Numerical Analysis of Closer Back-to-Back Reinforced Soil Walls: Effect of Reinforcement Arrangement

Numerical Analysis of Closer Back-to-Back Reinforced Soil Walls: Effect of Reinforcement Arrangement | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Numerical Analysis of Closer Back-to-Back Reinforced Soil Walls: Effect of Reinforcement Arrangement Hanan Bekkar, Mohamed Djabri, Alaoua Bouaicha, Ali Farik This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7618712/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 25 Nov, 2025 Read the published version in Transportation Infrastructure Geotechnology → Version 1 posted You are reading this latest preprint version Abstract Back-to-Back Mechanically Stabilized Earth Walls (BBMSEWs) are a frequently form of retaining walls with complex geometry and widely used in numerous geotechnical constructions especially in the bridge approaches. Current design guidelines for BBMSEWs are limited where the Federal Highway Administration recommendations provide a concise overview of the design of this structure. In this paper, the assessment of connected and unconnected closer BBMSEWs under applied static loads was numerically investigated by using two-dimensional finite element analysis. This study deal with the influence of the reinforcement layers and applied static surcharge loads on the behavior of BBMSEWs by analyzing four numerical models of walls with different arrangement of geosynthetic reinforcement under various charge intensity. For the comparison, the factor of safety and the horizontal wall displacement were preferred for external stability, while the maximum tensile load in reinforcement was selected to evaluate internal stability of walls. The most important findings indicate that the arrangement of reinforcement significantly influences the response of BBMSEWs. GRSWalls Wall displacement Numerical analysis Maximum tensile load Static load Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 1 Introduction The design of Mechanically Stabilized Earth Walls (MSEWs) is more intricate than that of conventional retaining walls due to the interaction between soil and reinforcement materials (Hazirbaba et al., 2019 ). Unlike conventional walls that rely on mass and rigidity, MSEWs depend on a composite system of soil and reinforcements, requiring careful consideration of internal, external, and global stability. This complexity demands a more detailed analysis of soil behavior, reinforcement properties, and construction methods to ensure long-term stability and safety. Mechanically Stabilized Earth Walls, particularly those using geosynthetic-reinforced soil technology namely noted GRSWs, have become an important structure in modern geotechnical and civil engineering because of their cost-efficiency, construction simplicity, and adaptability to diverse site conditions. These structures with horizontal layers of reinforcement enhance soil stability and load-bearing capacity, offering reliable solutions for retaining walls (Tatsuoka et al. 2014 ). Back-to-back Mechanically Stabilized Earth Walls (BBMSEWs) configuration is being increasingly employed in bridge abutments, highway ramps, railway particularly in urban or confined areas and present a design and performance challenges due to complex interactions between adjacent reinforced zones. In 2009, the Federal Highway Administration (FHWA) provided design and construction guidelines for such systems (Berg et al. 2009 ). The design approach of these structures is generally based on the distance where two cases were identified and detailed in (Berg et al. 2009 (Fig. 1 ). In recent decades, the behavior of BBMSEWs under static and dynamic loading using limit equilibrium approach, experimental techniques and numerical modeling was reported in several studies. These studies have significantly advanced the understanding of the mechanical behavior and interaction mechanisms within such systems, while also exploring various factors that influence their performance. Among the first researches specifically addressing BBMSEWs that conducted by Han and Leshchinsky ( 2010 ). The authors examined the performance of BBMSEWs with segmental block facings using limit equilibrium approach and the finite difference method based in FLAC software. Their parametric analysis focused on two key variables: the ratio of wall width to height and the properties of the backfill material and the results were evaluated in terms of the required tensile strength of the reinforcement, the location of the critical failure surface, and the lateral earth pressures behind the reinforced zone. In addition, multiple researchers have highlighted the advantages of incorporating geosynthetics into geotechnical infrastructure to enhance performance and stability (Chawla and Shahu 2016a ; Chawla and Shahu 2016b ; Chawla et al. 2021 ). Anubhav and Basudhar (2012) and Katkar and Viswanadham ( 2012 ) investigated the performance of BBMSEWs through experimental testing. Complementary numerical analyses were conducted by Hardianto and Turong (2010) to further understand the behavior of these wall systems. Based on the large-scale instrumented test wall reported by Won and Kim ( 2007 ), El-Sherbiny et al. ( 2013 ) investigated various wall width-to-height ratios (W/H) of BBMSEWs. The study revealed that when the D/H ratio is less than 1, interaction occurs between the two MSEWs, leading to decreased earth pressure as a result of the incomplete formation of the failure wedge. Djabri and Benmebarek ( 2016 ) and Benmebarek et al. ( 2016 ) assessed the stability of BBMSEWs using the numerical analysis software PLAXIS. Their study examined how the (W/H) ratio influences lateral earth pressures, critical failure surface and tensile forces within reinforcements. They also evaluated the impact of backfill material quality on the overall factor of safety. In a subsequent study, Benmebarek and Djabri ( 2017a ) explored the influence of reinforcement overlap length in BBMSEWs systems. Further, Benmebarek and Djabri ( 2017b ) carried out a numerical investigation on the dynamic response of BBMSEWs under various harmonic loading. Balunaini et al. ( 2017 ) examined the influence of surcharge loading and compaction on the structural behavior of BBMSEWs considering both connected and unconnected configurations. The results indicated that, for stiff and unconnected reinforcements, lateral pressures extended deep along the wall. However, in the case of connected reinforcements, these effects diminished with depth due to the arching phenomenon. The results given by Pour and Kalantari (2018) showed that shorter reinforcement lengths and lower tensile strengths can be effectively used when the soil has a higher internal friction angle and cohesion. Also, using different materials in layered configurations leads to improved overall performance, structural optimization, and lowers the required strength of reinforcement elements. Sravanam et al. ( 2019 ) investigated the lateral earth pressures and the tensile load in reinforcement for BBMSEWs subjected to compaction and surcharge loads across various (W/H). The study conducted by Sravanam et al. ( 2020a ) explored both connected and unconnected BBMSEWs systems focusing primarily on the tensile force distribution within the reinforcement under working stress conditions. The effect of reinforcement stiffness on structural response was also assessed. Later, Sravanam et al. ( 2020b ) proved that connected BBMSEWs can be effectively designed using the same approach as unconnected walls, which contrasts with the approach recommended by the FHWA guidelines (Berg et al. 2009 ). Dram et al. ( 2021 ) utilized PLAXIS 2D to check the seismic behavior of connected and unconnected BBMSEWs. They found that connecting the reinforcement at the middle significantly influenced key performance criteria, including maximum displacements, tensile forces within the geogrid, and dynamic earth pressure distribution. Additionally, the numerical analysis carried out by Xu et al. ( 2021 ) shows that increasing wall height has a decreasing impact on bearing capacity. As reported in studies (Samee et al. 2021a ; Samee et al. 2021b ), the performance of BBMSEWs with steel layers under seismic conditions was studied using a series of 1g shaking table tests. Their main results indicated that separating the opposing walls and shortening the length of the reinforcement overlap increases the lateral deformation and reduces the wall stability. Najafizadeh et al. ( 2022 ) used physical modeling and Particle Image Velocimetry (PIV) to examine how variations in wall spacing and applied loading influence the performance of back-to-back anchored retaining walls and shallow foundations. The study found that an effective distance of about 2.5 times the wall height minimizes interaction between the walls. Recently, Zheng et al. ( 2023 ) confirmed that the acceleration amplification factors generally increase with elevation and the maximum value is found at the uppermost section of the wall. Yazdandoust and Daftari ( 2024 ) studied how reinforcement type and layout affect BBMSEWs supporting railways. They found that reinforcement stiffness improves bearing capacity more than pull-out resistance. Connecting walls with continuous reinforcements gave the best results, while fully separated reinforcements performed worst. In more recently numerical study, Attallaoui et al. ( 2024 ) explored the dynamic behavior of Back-to-Back Mechanically Stabilized Earth walls using the finite element code PLAXIS. The study revealed that closer wall spacing increases system flexibility and shifts maximum displacement downward, reducing potential damage at the crest. It also showed that tensile forces in reinforcement layers under earthquake loading exceed those predicted by the FHWA method, emphasizing the importance of considering wall-to-wall interaction in BBMSEWs design. In the same way, Rahimi et al. ( 2024 ) conducted nonlinear dynamic analyses of a validated BBMSEWs model using the finite difference method integrated in FLAC2D software to develop fragility curves under far-field and near-field seismic conditions. Their study showed that increasing metal strip overlap significantly reduces seismic vulnerability by up to 35% for far-field and 50% for near-field earthquakes. Additionally, vector fragility curves were found to provide more accurate vulnerability assessments than scalar curves. In the latest study focusing the bahaviour of this special configuration, Rahmouni et al. ( 2025 ) investigated the influence of interaction distance between two railroad loadings on the static behavior of BBMSEWs using FLAC. Parametric analyses revealed how varying loading distances affect soil bearing capacity, failure mechanisms, reinforcement loads, wall displacements, and lateral earth pressure. The literature review indicates that most studies on BBMSEWs have focused on wall spacing and seismic loading, with limited attention to wall configurations effects, highlighting the need for advanced numerical and experimental investigations to deal with this situation. This paper aim to examine and discuss the static performance of connected and unconnected back-to-back geosynthetic reinforced soil walls (Case 1) using Finite Element Method included in PLAXIS 2D. Particularly, this research evaluate the effects of surcharge load values and reinforcement arrangement disposition, factors rarely addressed in existing literature, on wall displacement, safety factor and tensile force in reinforcement. 2 Model Description 2.2 Configuration and Parameters of the Baseline Model Nowadays, Finite Element Method (FEM) is extensively used in structural analysis and offers significant advantages over analytical methods, particularly for structures with complex geometries and arbitrary boundary conditions (Do and Hoang 2025 ). Therefore, this research investigates a series of BBMSEWs using PLAXIS 2D V8.2 software applied FEM (Brinkgreve 2018). It is worth emphasizing that PLAXIS is a robust and widely adopted tool in geotechnical engineering, frequently employed in numerous researchers (Nu et al. 2020 ; Khalid and Alshameri 2021 ). Moreover, it has been previously employed in several investigations focusing on BBMSEWs under various loading conditions. In the baseline model configuration, the wall height (H) was fixed at 6 m, with a toe embedment depth of 0.6 m, as illustrated in Fig. 2 . The wall width was set at 8.4 m, yielding a (W/H) ratio of 1.4 and the spacing between the two opposing walls was 0 m. Each wall included eight layers of geosynthetic reinforcement, each 4.2 m long (L = 0.7H), in accordance with the standard reinforcement length suggested by FHWA guidelines (Berg et al. 2009 ). These reinforcements were anchored to four precast concrete facing panels, each measuring 1.50 m in both width and height. The foundation soil was modeled to a depth of 6 m, with both the native and reinforced soils treated as homogeneous materials governed by the Mohr-Coulomb failure criterion. The geosynthetic reinforcements, characterized by a tensile stiffness of EA = 2500 kN/m, and the panels, which properties are listed in Table 1 , were modeled as linear elastic behavior. Table 1 Material properties of concrete panel facing elements (Benmbarek and Djabri 2017) Model Axial stiffness (EA) (kN/m) Flexural rigidity (EI) (kN/m 2 /m) Thickness (d) (m) Weight (Wc) (kN/ m/m) Poisson ratio (ν) Elastic 2250 4220 0.474 3.750 0.2 Table 2 summarizes the key geotechnical and mechanical characteristics of the reinforced soils as documented in previous experimental and numerical studies conducted by (Benmbarek and Djabri 2017). Table 2 Characteristics of the foundation soil, reinforced and retained backfills (Benmbarek and Djabri 2017) Properties Symbol Unit Reinforced soil Foundation soil Material model - - Mohr-Coulomb Mohr-Coulomb Material type - - Drained Drained Unit weight γs kN/m 3 16 22 Cohesion c kN/m 2 0.2 100 Poisson’s ratio ν - 0.3 0.3 Angle of shearing resistance ϕ deg. 34 30 Dilation angle ψ deg. 0 0 Deformation modulus E kN/m 2 4x10 4 5 x10 4 The reinforcement layers and facing elements were installed sequentially alongside the placement of backfill layers. This procedure was repeated for each layer until the full structure was completed. Upon completion of the construction phase, which accounted solely for the self-weight of the backfill, the model was prepared for the application of external static loading. 2.2 Geometry of the Models Used in the Comparative Study This paper examines four configurations of reinforcements for closer connected and unconnected BBMSEWs (Fig. 3 ). The configurations chosen in this study at different arrangements of reinforcement layers was recently selected by other authors read a dynamic analysis of reinforced soil retaining wall (Samee et al. 2021b ). In the first model such as wall A, the opposing walls were connected using continuous integrated strips. In the wall B, eight separate rows of non-overlapping strips were used. For wall C, the lower four reinforcement layers were unconnected and the four upper layers are connected. Conversely, in the wall D, the four upper geosynthetic reinforcements are unconnected, with the lower four strips being connected (Fig. 3 ). 3 Results and Discussion The retaining walls stability was assessed based on four criteria, the external stability was assessed through horizontal wall displacements and overall factor of safety; the internal stability was verified by examining the maximum tensile with as its location (i.e., its distance from the wall facing) in each reinforcement. The geosynthetic arrangements were varied under a range of uniform static surcharge loads, increasing from 20 to 100 kN/m². The analysis results are presented as graphical profiles illustrating how the response of BBMSEWs varied with different reinforcement arrangements and levels of applied static surcharge loading. 3.1 Horizontal Wall Displacement According to the Reinforcement Arrangement The results evidently show that the maximum horizontal displacement occurs at the Mid-wall when the load is small, i.e. 20kN/m 2 and keep the same position after increasing the surcharge to 100 kN/m 2 (Fig. 4 ). The maximum horizontal displacements for all walls were described by curves (Fig. 5 ). The numerical results confirmed that wall displacement increases as the value of static surcharge loads on the wall increases. In the other hand, the findings illustrate that the displacements in connected walls, i.e wall A are lower than those in unconnected walls, i.e, wall B; the deformation in connected walls is approximately 50% less than in unconnected walls. By comparing wall A with wall B, it was shown that the horizontal wall displacement is lower for a wall A compared to wall B, which gives a greater value, because the reinforcements in it are not connected. Note that the difference between wall A and wall B when q = 20 kN/m 2 is about 70%, and the later was found to be 100% when the surcharge was increased five times. Also, when comparing the wall C with wall D, increasing the surcharge from 20 kN/m 2 to 100 kN/m 2 involves an increasing of the maximum wall displacement where the difference is 21% and 40% respectively. It should be noted that in wall C, the four layers at the less half of the wall are unconnected and the four upper strips are connected. Conversely, in the wall D, the four upper strips are unconnected. 3.2 Factor of Safety The numerical results indicate that the factor of safety (FS) varies depending on the disposition of reinforcement and the load values on each wall (Fig. 6 ). The findings confirmed that an increase in the values of the surcharge lead to decrease the factor of safety. As noticed in the case of wall A, in which the reinforcements are all connected, the factor of safety take high values compared with the case in which the reinforcements are unconnected in wall B where Fs have a low values. For example, comparing the wall A with wall B it was found that the decreasing difference is 100% under a surcharge of 100 kN/m 2 . Also, when comparing the wall C with wall D it was found that when the four upper strips are connected and the four strips of the lower half of the walls are unconnected; FS takes larger values that compared to the inverse case, i.e wall D. For example, the value of FS increased from 1.7 to 1.95 under the influence of a load 100 kN/m 2 illustrating that arrangement of reinforcement significantly affects the permanence of BBMSEWs in term of the factor of safety. 3.3 Maximum Tension Load Respecting Reinforcement Arrangement Figure 7 illustrates the curves evolution of maximum reinforcement tensile in reinforcement (Tmax) at which have the same look for all cases. It is also evident that the position and value of Tmax was located in the second line from the base of the wall, with one value was mentioned for wall F under 100 kN/m 2 surcharge load (Fig. 7 b). Moreover, it is possible to see that wall B presented the greater values of Tmax observed during surcharge application, in which the reinforcements are unconnected and with the differences up to 62.25% in relation to wall A; i.e, connected case. Furthermore, the load values significantly influences the tensile load in reinforcement, for information, in the wall C case, increasing the surcharge for a five times involves an increase of Tmax about 77.44% (Fig. 7 b). To judge the effect of the reinforcement distribution, the curves show that wall C presented the small values of Tmax compared to wall D (maximum decreasing difference of 26.93%), indicating that reversed arrangement of reinforcement mainly influences the reinforcement tensile loads. Furthermore, when comparing the wall A with the wall B, the wall C with the wall D respectively, it was found that where q = 20 kN/m 2 the difference is varying 43.13% up to 62.30% respectively; this difference become 14.39% and 26.93% after applying a surcharge of 100 kN/m 2 . The potential line of maximum tensile load is shown in Fig. 8 . It can be seen that at the bottom of the retaining walls, the difference is negligible (except at the top), where the difference is very small. These results indicated that the potential line of maximum tensile load is not as influenced by the disposition of the reinforcement and that it is very close to the line given in the FHWA 2009 guidelines. 4 Conclusion Back-to-back Mechanically Stabilized Earth Walls (BBMSEWs) involve complex geometries and substantial external loads, making it difficult to distinguish between internal and external stability during design and construction. This complexity has prompted growing interest from researchers aiming to better understand the behavior of these systems. Despite existing studies and design guidelines, the behavour of BBMSEWs remains not fully understood and numerical analysis proves to be a valuable tool for enhancing current knowledge in this field. In this paper, two-dimensional numerical modelling using a finite element PLAXIS code was carried on the behavour of four closer connected and unconnected BBMSEWs. This research specially examined how the reinforcement disposition affects the stability of these structures and several comparative studies were carried out leading to the following key findings: The finite element method demonstrated that horizontal wall displacement increases proportionally with increasing static surcharge load. On the other hand, when the static surcharge loads values increased for five times, the maximum tensile force in reinforcement increased by about 60%. Mid-wall connections lead to a significant reduction in horizontal displacement by approximately 19% and substantially improve the factor of safety, increasing it from 2 to 7 compared to unconnected walls. The arrangement of the reinforcement had a significant impact on horizontal wall displacement. In light, when the four strips of the lower half of the wall are connected and the four upper strips are unconnected the maximum displacement was very less than that of in the conversely case. On the contrary, the factor of safety was slowly increased for the same compared walls. The unconnected walls exhibited slightly higher and more uniform maximum tensile forces compared to the connected walls. Moreover, significant tensile forces were observed in the reinforcements close to the base and occurred at a height of 0.9 m from the bottom of the wall. Furthermore, in the configuration where the lower half of the wall contains four unconnected reinforcement strips and the four upper strips are connected, the maximum tension load is lesser than that of in the conversely case where the four upper strips are unconnected. The potential line of maximum tensile load was not influenced by the reinforcement arrangement at the same at the distribution surcharge load as found in the first part of the study. The lines given in this numerical study was similar at these provide by the FHWA 2009 guidelines. This research offers valuable insights regarding the behavior of BBMSEWs under static loading, enhancing the overall understanding of their performance. However, it does not consider certain factors such as soil compaction and compressible foundation conditions, which may also influence their response behavior. While offering important insights into their static response, it does not account for factors such as soil compaction and compressible foundation conditions. Future research should explore additional parameters under both static and dynamic conditions, including wall height variations, reduced reinforcement lengths, different reinforcement layout and backfill soil types. Additionally, these findings should be validated through physical model testing to ensure practical applicability and reliability. Declarations Author Contribution H.B. and M.D.: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Writing - Original DraftH. B, M.D., A.B. and A.F.: Conceptualization, Methodology, Validation, Investigation, Writing - Review & Editing, Supervision References Attallaoui, S., Benmebarek,S ., Benmebarek, N.: Numerical Analysis of Seismic Response of Back-to-Back Mechanically Stabilized Earth Walls. International review of Civil Engineering, 15 (2024). https://doi.org/10.15866/irece.v15i2.23538 Anubhav, S., Basudhar, P. K.: Numerical modelling of surface strip footings resting on double-faced wrap-around vertical reinforced soil walls. Geosynthetics International 18, 21–34 (2011). https://doi.org/10.1680/gein .2011.18.1.21 Balunaini, U., Sravanam, S. M., Madhav, M. R.: Effect of compaction stresses on performance of back-to-back retaining walls. In Proc., 19th Int. Conf. Soil Mechanics and Geotechnical Engineering, edited by Lee,W., Lee, J. S., Kim H. K., Kim D. S, 1951–1954. London: International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) (2017). Benmebarek, S., Attalaoui, S., Benmebarek, N.: Interaction analysis of back-to-back mechanically stabilized earth walls. Journal of Rock Mechanics and Geotechnical Engineering 8, 697-702 (2016). https://doi.org/10.1016/j.jrmge.2016.05.005 Benmebarek, S. and Djabri, M.: FEM to investigate the effect of overlapping-reinforcement on the performance of back-to-back embankment bridge approaches under self-weight. Transportation Geotechnics 11, 17-26 (2017a). https://doi.org/10.1016/j.trgeo.2017.03.002 Benmebarek, S., Djabri, M.: FEM analysis of back-to-back mechanically stabilized earth walls under cyclic harmonic loading. Indian Geotechnical Journal 48, 498-509 (2017b). https://doi.org/10.1007/s40098-017-0269-z Berg, R. R., Christopher, B. R., Samtani, N. C.: Design of mechanically stabilized earth walls and reinforced soil slopes, design & construction guidelines, Report No. FHWA-NHI-00-043, 394pp (2009). Brinkgreve, R.B.J.: "Manual for Plaxis 2D" version8, Balkema, Netherlands (1998). Chawla, S., Shahu, J.T.: Reinforcement and mud-pumping benefits of geosynthetics in railway tracks: Model Tests. Geotextiles and Geomembranes 44, 366–80 (2016a). https://doi. org/10.1016/j.geotexmem.2016.01.005 Chawla, S., Shahu, J.T.: Reinforcement and mud-pumping benefits of geosynthetics in railway tracks: Numerical Analysis. Geotextiles and Geomembranes 44, 344–57 (2016b). https://doi.org/10.1016/j.geotexmem.2016.01.006 Chawla, S., Shahu, J.T., Kumar, S.: Analysis of cyclic deformation and post-cyclic strength of reinforced railway tracks on soft subgrade. Transportation Geotechnics 28, 100535 (2021). https://doi.org/10.1016/j.trgeo.2021.100535 Djabri, M., Benmebarek, S.: FEM analysis of back-to-back geosynthetic-reinforced soil retaining walls. International Journal of Geosynthetics and Ground Engineering 2, 26 (2016). https://doi.org/10.1007/s40891-016-0067-1 Do, N-T., Hoang N.T.: The uncertain free vibration analysis of functionally graded sandwich plates placed on a variable elastic foundation. Latin American Journal of Solids and Structures 22, e8506 (2025). https://doi.org/10.1590/1679-7825/e8506 Dram, A., Balunaini, U., Benmebarek, S., Sravanam, S.M., Madhav, M.R.: Earthquake response of connected and unconnected back-to-back geosynthetic-reinforced soil walls. International Journal of Geomechanics 21, 1532-3641(2021). https://doi.org/10.1061/(ASCE)GM.1943-5622.0002206 El-Sherbiny, R., Ibrahim, E., Salem, A.: Stability of back-to-back mechanically stabilize earth walls. In: Proceedings of Geo-Congress: Stability and Performance of Slopes and Embankments III. Reston, USA: American Society of Civil Engineers (ASCE), 555e65 (2013). http://dx.doi.org/10.1061/9780784412787.058 Han, J., Leshchinsky, D.: Analysis of back-to-back mechanically stabilized earth walls. Geotextiles and Geomembranes 28, 262-267 (2010). https://doi.org/10.1016/j.geotexmem.2009.09.012. Hardianto, F. S., Truong, K. M.: Seismic deformation of back-to- back mechanically stabilized earth (MSE) walls. In Earth Retention Conf. 3, Geotechnical Special Publication 208, edited by R. Finno, Y. M. A. Hashash, and P. Arduino: 704–711. Reston, VA: ASCE (2010). https://doi.org/10.1061/41128(384)70 Hazirbaba, K., Mugheida, O., Abu-Lebdeh, G.: A critical review on seismic design of earth-retaining structures. Jordan Journal of Civil Engineering 13, 61-69 (2019). Katkar, B.H., Viswanadham, B.V.S.: Centrifuge Studies on the behavior of back-to-back geogrid reinforced soil walls. Proc. of the Ist Asian Workshop on Physical Modelling in Geotechnics, 14-16, Bombay, India (2012). Khalid, M. H., Alshameri, B.: Determination of safe depth and lateral distance of unsupported excavation near mat foundation in cohesive soils using PLAXIS. Journal of Applied Science and Engineering 25, 249-260 (2021). https://doi.org/10.6180/jase.202204_25(2).0011 Najafizadeh, A., Zad, A. A., Yazdi, M.: Experimental evaluation of back-to-back anchored walls by single plate anchors. International Journal of Geomechanics 22, 04022221 (2022). https://doi.org/10.1061/(ASCE)GM.1943-5622.0002470 Nu, N. T., Van Loi, B., Huong, N. T. T.: An analytical model for residual stress prediction in rebound deformation of the foundation pit. Journal of Applied Science and Engineering 23, 661-668 (2020). https://doi.org/10.6180/jase.202012_23(4).0010 Pour, M. T., Kalantari, B.: Parametric analysis of back-to-back reinforced earth retaining walls. Pamukkale University. Journal of Engineering Sciences 25, 247-256 (2019). https://doi: 10.5505/pajes.2018.22308 Rahimi, M., Firoozfar, A., Alielahi, H.: Fragility curves for seismic vulnerability of Back-to-Back mechanically stabilized earth walls. Geotechnical and Geological Engineering 42, 7525-7552 (2024). https://doi.org/10.1007/s10706-024-02938-7 Rahmouni, O., Belkebir, M., Baazouzi, M., Belhocine, M., Mabrouki, A.: Numerical analysis of back-to-back mechanically stabilized earth walls subjected to dual railroad loadings. International Journal of Geotechnical Engineering 19, 50-61 (2025). https://doi.org/10.1080/19386362.2024.2445845 Samee, A. A., Yazdandoust, M., Ghalandarzadeh, A.: Effect of reinforcement arrangement on dynamic behavour of back-to-back mechanically stabilised earth walls. International Journal of Physical Modelling in Geotechnics 22, 1-38 (2021a). https://doi.org/10.1680/jphmg.20.00088 Samee, A. A., Yazdandoust, M., Ghalandarzadeh, A.: Performance of back-to-back MSE walls reinforced with steel strips under seismic conditions. Transportation Geotechnics 30, 100540 (2021b). https://doi.org/10.1016/j.trgeo.2021.100540 Sravanam, S. M., Umashankar, B., Madhira, R.M.: Behavior and design of back-to-back walls considering compaction and surcharge loads. International Journal of Geosynthetics and Ground Engineering 5, 5-31 (2019). https://doi.org/10.1007/s40891-019-0180-z Sravanam, S. M., Umashankar, B., Madhira, R.M.: Behavior of connected and unconnected Back-to-Back Walls for Bridge Approaches. International Journal of Geomechanics 20, 06020013 (2020a). https://doi.org/10.1007/s10706-020-01435-x Sravanam, S. M., Umashankar, B., Madhira, R.M.: Analysis of single and back-to-back reinforced retaining walls with full-length panel facia. Geotechnical and Geological Engineering 6, 6281-6293 (2020b). https://doi.org/10.1007/s10706-020-01435-x. Tatsuoka, F., Tateyama, M., Koseki, J.,Yonezawa, T.: Geosynthetic-reinforced soil structures for railways in Japan. Transportation Infrastructure Geotechnology 1, 3-53 (2014). https://doi.org/10.1007/s40515-013-0001-0 Won, M.S., Kim, Y.S.: Internal deformation behavior of geosynthetic-reinforced soil walls. Geotextiles and Geomembranes 25, 10-22 (2007). https://doi.org/10.1016/j.geotexmem.2006.10.001 Xu , P., Yang , G., Li , T., Hatami, K.: Finite element limit analysis of bearing capacity of footing on back-to-back reinforced soil retaining walls. Transportation Geotechnics 30, 100596 (2021) https://doi.org/10.1016/j.trgeo.2021.100596 Yazdandoust, M., Daftari, F.: Behavior of back-to-back mechanically stabilized earth walls as railway embankments. Geosynthetics International 31, 785-805 (2024). https://doi.org/10.1680/jgein.23.00126 Zheng, Y., Li, F., Guo, W., Wang, P., Yang, G.: Influence of facing conditions on the dynamic response of back-to-back MSE walls. Soil Dynamics and Earthquake Engineering 164, 107650 (2023). https://doi.org/10.1016/j.soildyn.2022.107650 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 25 Nov, 2025 Read the published version in Transportation Infrastructure Geotechnology → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7618712","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":522492505,"identity":"7f88a038-7450-4e66-963a-c610af090900","order_by":0,"name":"Hanan Bekkar","email":"","orcid":"","institution":"Research Laboratory of Sedimentary Environment, Mineral \u0026 Water Resources of Eastern Algeria, Department of Earth and Universe Sciences, Echahid Cheikh Larbi Tebessi-Tebessa University","correspondingAuthor":false,"prefix":"","firstName":"Hanan","middleName":"","lastName":"Bekkar","suffix":""},{"id":522492506,"identity":"a81f3f3a-a0d8-4a35-b239-74158d1d9441","order_by":1,"name":"Mohamed Djabri","email":"data:image/png;base64,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","orcid":"","institution":"Research Laboratory of Sedimentary Environment, Mineral \u0026 Water Resources of Eastern Algeria, Department of Earth and Universe Sciences, Echahid Cheikh Larbi Tebessi-Tebessa University","correspondingAuthor":true,"prefix":"","firstName":"Mohamed","middleName":"","lastName":"Djabri","suffix":""},{"id":522492508,"identity":"86a1cf05-ee59-45bf-8521-5264888f07c7","order_by":2,"name":"Alaoua Bouaicha","email":"","orcid":"","institution":"Scientific and Technical Research Center on Arid Regions CRSTRA, Campus of Mohamed Khider University","correspondingAuthor":false,"prefix":"","firstName":"Alaoua","middleName":"","lastName":"Bouaicha","suffix":""},{"id":522492510,"identity":"6dd5f9e6-7e17-4cdd-9377-14ba9f860471","order_by":3,"name":"Ali Farik","email":"","orcid":"","institution":"Hydraulics and Civil Engineering Department, Laboratory of New Technologies and Local Development, University of El Oued","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"","lastName":"Farik","suffix":""}],"badges":[],"createdAt":"2025-09-15 09:23:37","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7618712/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7618712/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s40515-025-00748-9","type":"published","date":"2025-11-25T15:58:41+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":92500134,"identity":"29124404-d7e0-404a-a88a-cdb478161ee4","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":536007,"visible":true,"origin":"","legend":"","description":"","filename":"Bekkaretal.Transpinfgeot15092025.docx","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/918cdab5fea30f86c3dc864b.docx"},{"id":92501485,"identity":"1397494b-50b5-4f1f-8f1d-fab0667d7474","added_by":"auto","created_at":"2025-09-30 11:26:11","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":5378,"visible":true,"origin":"","legend":"","description":"","filename":"b3eaec6218f24891b7472ccece95f4d1.json","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/6f92969c3023cc610734e898.json"},{"id":92500353,"identity":"84bf3585-3da9-498a-848f-4b36f5f27933","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"xml","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":86711,"visible":true,"origin":"","legend":"","description":"","filename":"b3eaec6218f24891b7472ccece95f4d11enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/69376cacbb5e3bc83c52c238.xml"},{"id":92500132,"identity":"cc097cb9-a31b-4020-a3dd-5bb53d99c84c","added_by":"auto","created_at":"2025-09-30 11:10:10","extension":"png","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":42677,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/3f802d8ce9a4e92271cd1cf8.png"},{"id":92500142,"identity":"6a112120-f8b8-410f-9822-6131636a4980","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":95335,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/2f748907721cb0d0d9061724.png"},{"id":92500360,"identity":"a55d7164-47ad-4fa5-9bd0-29f5b3ee185b","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"png","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":160678,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/4b9d7504556e8fa56cae7c3d.png"},{"id":92500149,"identity":"348c4119-f2fc-4c9c-b9bd-a94432adb8e3","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":48555,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/f4e6871e44ce74d9fe7f1fa6.png"},{"id":92500356,"identity":"00341201-5feb-4004-886e-555f79afa70f","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":14840,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/1cc3c2f18a6c4eb9d6de5be9.png"},{"id":92500155,"identity":"8c474a18-b903-47c1-9b06-02e7d16111b9","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":11900,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/c4c17c909057007e52473a80.png"},{"id":92500146,"identity":"025dbd3d-7d95-43eb-8297-b0cd7ed48474","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":55769,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/30381feb5bd5a3a182cc0459.png"},{"id":92500357,"identity":"8ee6985e-0e06-4059-8121-0306f7c47cd0","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":50473,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/a1dfbef823da66a5e665f160.png"},{"id":92500358,"identity":"00978214-a5ec-4e83-b054-c59d5d9e0625","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":21589,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/7a4aef2cada594c93fbd09da.png"},{"id":92501488,"identity":"06c1f0e1-90d3-401f-a0bc-1964ff037b67","added_by":"auto","created_at":"2025-09-30 11:26:11","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":22114,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/cb99ea5cb0a825f9ae9fc190.png"},{"id":92500154,"identity":"f9f21143-631e-4c6f-9ddc-03d1a919b7a6","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":27965,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/b42d6360be605cd34f2533da.png"},{"id":92500362,"identity":"485db4f5-f82e-4623-b507-7385ae00908f","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":19582,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/9fc082f9ebf245e604e66c2c.png"},{"id":92500153,"identity":"4f37b5f2-ab35-433e-b4aa-c3807cb48b2f","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":5198,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/1d43fc28dfd2d71800b1012d.png"},{"id":92500363,"identity":"f11aadeb-ef75-4cec-b951-e73855278be4","added_by":"auto","created_at":"2025-09-30 11:18:11","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":4489,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/e6a5bae8dbaf630514003c02.png"},{"id":92500148,"identity":"d4580051-4701-462b-aeac-12109bef425c","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":23744,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/1a4e3efb1778d7cf09f6cf20.png"},{"id":92501793,"identity":"dc4dc376-e3e4-4ad8-b161-e8f7ffbbf7b2","added_by":"auto","created_at":"2025-09-30 11:34:11","extension":"png","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":19133,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/41fe794e70dabb234ba059ec.png"},{"id":92500158,"identity":"e36f66ee-77d4-4827-ac7b-fe878dbf0fc8","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"xml","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":85434,"visible":true,"origin":"","legend":"","description":"","filename":"b3eaec6218f24891b7472ccece95f4d11structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/cfc3bceae232dc37095e265f.xml"},{"id":92500160,"identity":"375f9848-fc40-42dd-9fb8-5a1c869d6448","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"html","order_by":20,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":91081,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/76458fbdb3b9da4476426bb2.html"},{"id":92500130,"identity":"1bd3a8ee-b80f-4f34-8907-905916d8d2ee","added_by":"auto","created_at":"2025-09-30 11:10:10","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":42677,"visible":true,"origin":"","legend":"\u003cp\u003eThe design of BBMSEWs (Berg et al. 2009)\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/23f2a732cce27be1861acd37.png"},{"id":92500131,"identity":"643824cd-afb3-4867-acc3-a05f0f67f178","added_by":"auto","created_at":"2025-09-30 11:10:10","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":95335,"visible":true,"origin":"","legend":"\u003cp\u003eThe geometry of basic Closer BBMSEWs model subject to static surcharge loads\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/0b9ff6328190b02b0eccfd1b.png"},{"id":92500138,"identity":"de73ae30-01c6-4fc0-ade3-04ad22ca79a4","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":160678,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic of BBMSEWs at different reinforcement arrangement with D=0m and W/H =1.40\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/cf8cff3318072e99eaca3315.png"},{"id":92500140,"identity":"7bd3f11a-3d58-40a6-b6db-c301f101694b","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":59727,"visible":true,"origin":"","legend":"\u003cp\u003eHorizontal wall displacement for different surcharge values: (a) for q=20 kN/m\u003csup\u003e2\u003c/sup\u003e, (b) for q=100 kN/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/2de47f6cca96124da22fc8c8.png"},{"id":92501792,"identity":"711b17b6-cd1f-46ea-a697-bf49f96fcabd","added_by":"auto","created_at":"2025-09-30 11:34:11","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":14840,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of maximum horizontal wall displacement with the respect of values of external load and distribution of reinforcement\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/a4d739e521e6d47604c94cab.png"},{"id":92500139,"identity":"f2f8e4d5-6c89-452e-84fd-38e0c2f02f07","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":11900,"visible":true,"origin":"","legend":"\u003cp\u003eValues of the factor of safety (FS) for walls with the respect of the reinforcement arrangement\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/746b68dfd91a703de6c6c7c5.png"},{"id":92500159,"identity":"01102702-79ce-4591-a201-3ce561e79018","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":72577,"visible":true,"origin":"","legend":"\u003cp\u003eMaximum tensile loads in reinforcement: (a) for q=20 kN/m\u003csup\u003e2\u003c/sup\u003e, (b) for q=100 kN/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/f454dcc412677ae626087a22.png"},{"id":92500144,"identity":"6a597108-d820-44d5-9385-db3e9f5e4d9d","added_by":"auto","created_at":"2025-09-30 11:10:11","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":66057,"visible":true,"origin":"","legend":"\u003cp\u003ePotential line of maximum tensile load: (a) for q=20kN/m\u003csup\u003e2\u003c/sup\u003e, (b) for q=100kN/m\u003csup\u003e2\u003c/sup\u003e for different reinforcement arrangement\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/374bb8df756bdddf192e0e89.png"},{"id":97179554,"identity":"9abfc366-4a5a-4b26-933d-990a7e8db519","added_by":"auto","created_at":"2025-12-01 16:16:05","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1010342,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7618712/v1/f6ae215c-1b5b-40f8-adfa-fcadf508fa08.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Numerical Analysis of Closer Back-to-Back Reinforced Soil Walls: Effect of Reinforcement Arrangement","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eThe design of Mechanically Stabilized Earth Walls (MSEWs) is more intricate than that of conventional retaining walls due to the interaction between soil and reinforcement materials (Hazirbaba et al., \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Unlike conventional walls that rely on mass and rigidity, MSEWs depend on a composite system of soil and reinforcements, requiring careful consideration of internal, external, and global stability. This complexity demands a more detailed analysis of soil behavior, reinforcement properties, and construction methods to ensure long-term stability and safety. Mechanically Stabilized Earth Walls, particularly those using geosynthetic-reinforced soil technology namely noted GRSWs, have become an important structure in modern geotechnical and civil engineering because of their cost-efficiency, construction simplicity, and adaptability to diverse site conditions. These structures with horizontal layers of reinforcement enhance soil stability and load-bearing capacity, offering reliable solutions for retaining walls (Tatsuoka et al. \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e2014\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eBack-to-back Mechanically Stabilized Earth Walls (BBMSEWs) configuration is being increasingly employed in bridge abutments, highway ramps, railway particularly in urban or confined areas and present a design and performance challenges due to complex interactions between adjacent reinforced zones. In 2009, the Federal Highway Administration (FHWA) provided design and construction guidelines for such systems (Berg et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). The design approach of these structures is generally based on the distance where two cases were identified and detailed in (Berg et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2009\u003c/span\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn recent decades, the behavior of BBMSEWs under static and dynamic loading using limit equilibrium approach, experimental techniques and numerical modeling was reported in several studies. These studies have significantly advanced the understanding of the mechanical behavior and interaction mechanisms within such systems, while also exploring various factors that influence their performance.\u003c/p\u003e\u003cp\u003eAmong the first researches specifically addressing BBMSEWs that conducted by Han and Leshchinsky (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2010\u003c/span\u003e). The authors examined the performance of BBMSEWs with segmental block facings using limit equilibrium approach and the finite difference method based in FLAC software. Their parametric analysis focused on two key variables: the ratio of wall width to height and the properties of the backfill material and the results were evaluated in terms of the required tensile strength of the reinforcement, the location of the critical failure surface, and the lateral earth pressures behind the reinforced zone. In addition, multiple researchers have highlighted the advantages of incorporating geosynthetics into geotechnical infrastructure to enhance performance and stability (Chawla and Shahu \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2016a\u003c/span\u003e; Chawla and Shahu \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2016b\u003c/span\u003e; Chawla et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eAnubhav and Basudhar (2012) and Katkar and Viswanadham (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) investigated the performance of BBMSEWs through experimental testing. Complementary numerical analyses were conducted by Hardianto and Turong (2010) to further understand the behavior of these wall systems.\u003c/p\u003e\u003cp\u003eBased on the large-scale instrumented test wall reported by Won and Kim (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2007\u003c/span\u003e), El-Sherbiny et al. (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) investigated various wall width-to-height ratios (W/H) of BBMSEWs. The study revealed that when the D/H ratio is less than 1, interaction occurs between the two MSEWs, leading to decreased earth pressure as a result of the incomplete formation of the failure wedge.\u003c/p\u003e\u003cp\u003eDjabri and Benmebarek (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) and Benmebarek et al. (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e2016\u003c/span\u003e) assessed the stability of BBMSEWs using the numerical analysis software PLAXIS. Their study examined how the (W/H) ratio influences lateral earth pressures, critical failure surface and tensile forces within reinforcements. They also evaluated the impact of backfill material quality on the overall factor of safety. In a subsequent study, Benmebarek and Djabri (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e2017a\u003c/span\u003e) explored the influence of reinforcement overlap length in BBMSEWs systems. Further, Benmebarek and Djabri (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2017b\u003c/span\u003e) carried out a numerical investigation on the dynamic response of BBMSEWs under various harmonic loading.\u003c/p\u003e\u003cp\u003eBalunaini et al. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e2017\u003c/span\u003e) examined the influence of surcharge loading and compaction on the structural behavior of BBMSEWs considering both connected and unconnected configurations. The results indicated that, for stiff and unconnected reinforcements, lateral pressures extended deep along the wall. However, in the case of connected reinforcements, these effects diminished with depth due to the arching phenomenon. The results given by Pour and Kalantari (2018) showed that shorter reinforcement lengths and lower tensile strengths can be effectively used when the soil has a higher internal friction angle and cohesion. Also, using different materials in layered configurations leads to improved overall performance, structural optimization, and lowers the required strength of reinforcement elements.\u003c/p\u003e\u003cp\u003eSravanam et al. (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e2019\u003c/span\u003e) investigated the lateral earth pressures and the tensile load in reinforcement for BBMSEWs subjected to compaction and surcharge loads across various (W/H). The study conducted by Sravanam et al. (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2020a\u003c/span\u003e) explored both connected and unconnected BBMSEWs systems focusing primarily on the tensile force distribution within the reinforcement under working stress conditions. The effect of reinforcement stiffness on structural response was also assessed. Later, Sravanam et al. (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2020b\u003c/span\u003e) proved that connected BBMSEWs can be effectively designed using the same approach as unconnected walls, which contrasts with the approach recommended by the FHWA guidelines (Berg et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2009\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eDram et al. (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) utilized PLAXIS 2D to check the seismic behavior of connected and unconnected BBMSEWs. They found that connecting the reinforcement at the middle significantly influenced key performance criteria, including maximum displacements, tensile forces within the geogrid, and dynamic earth pressure distribution. Additionally, the numerical analysis carried out by Xu et al. (\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e2021\u003c/span\u003e) shows that increasing wall height has a decreasing impact on bearing capacity.\u003c/p\u003e\u003cp\u003eAs reported in studies (Samee et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2021a\u003c/span\u003e; Samee et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2021b\u003c/span\u003e), the performance of BBMSEWs with steel layers under seismic conditions was studied using a series of 1g shaking table tests. Their main results indicated that separating the opposing walls and shortening the length of the reinforcement overlap increases the lateral deformation and reduces the wall stability.\u003c/p\u003e\u003cp\u003eNajafizadeh et al. (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2022\u003c/span\u003e) used physical modeling and Particle Image Velocimetry (PIV) to examine how variations in wall spacing and applied loading influence the performance of back-to-back anchored retaining walls and shallow foundations. The study found that an effective distance of about 2.5 times the wall height minimizes interaction between the walls.\u003c/p\u003e\u003cp\u003eRecently, Zheng et al. (\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2023\u003c/span\u003e) confirmed that the acceleration amplification factors generally increase with elevation and the maximum value is found at the uppermost section of the wall. Yazdandoust and Daftari (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) studied how reinforcement type and layout affect BBMSEWs supporting railways. They found that reinforcement stiffness improves bearing capacity more than pull-out resistance. Connecting walls with continuous reinforcements gave the best results, while fully separated reinforcements performed worst.\u003c/p\u003e\u003cp\u003eIn more recently numerical study, Attallaoui et al. (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) explored the dynamic behavior of Back-to-Back Mechanically Stabilized Earth walls using the finite element code PLAXIS. The study revealed that closer wall spacing increases system flexibility and shifts maximum displacement downward, reducing potential damage at the crest. It also showed that tensile forces in reinforcement layers under earthquake loading exceed those predicted by the FHWA method, emphasizing the importance of considering wall-to-wall interaction in BBMSEWs design. In the same way, Rahimi et al. (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2024\u003c/span\u003e) conducted nonlinear dynamic analyses of a validated BBMSEWs model using the finite difference method integrated in FLAC2D software to develop fragility curves under far-field and near-field seismic conditions. Their study showed that increasing metal strip overlap significantly reduces seismic vulnerability by up to 35% for far-field and 50% for near-field earthquakes. Additionally, vector fragility curves were found to provide more accurate vulnerability assessments than scalar curves.\u003c/p\u003e\u003cp\u003eIn the latest study focusing the bahaviour of this special configuration, Rahmouni et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e2025\u003c/span\u003e) investigated the influence of interaction distance between two railroad loadings on the static behavior of BBMSEWs using FLAC. Parametric analyses revealed how varying loading distances affect soil bearing capacity, failure mechanisms, reinforcement loads, wall displacements, and lateral earth pressure.\u003c/p\u003e\u003cp\u003eThe literature review indicates that most studies on BBMSEWs have focused on wall spacing and seismic loading, with limited attention to wall configurations effects, highlighting the need for advanced numerical and experimental investigations to deal with this situation.\u003c/p\u003e\u003cp\u003eThis paper aim to examine and discuss the static performance of connected and unconnected back-to-back geosynthetic reinforced soil walls (Case 1) using Finite Element Method included in PLAXIS 2D. Particularly, this research evaluate the effects of surcharge load values and reinforcement arrangement disposition, factors rarely addressed in existing literature, on wall displacement, safety factor and tensile force in reinforcement.\u003c/p\u003e"},{"header":"2 Model Description","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Configuration and Parameters of the Baseline Model\u003c/h2\u003e\u003cp\u003eNowadays, Finite Element Method (FEM) is extensively used in structural analysis and offers significant advantages over analytical methods, particularly for structures with complex geometries and arbitrary boundary conditions (Do and Hoang \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2025\u003c/span\u003e). Therefore, this research investigates a series of BBMSEWs using PLAXIS 2D V8.2 software applied FEM (Brinkgreve 2018). It is worth emphasizing that PLAXIS is a robust and widely adopted tool in geotechnical engineering, frequently employed in numerous researchers (Nu et al. \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Khalid and Alshameri \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Moreover, it has been previously employed in several investigations focusing on BBMSEWs under various loading conditions.\u003c/p\u003e\u003cp\u003eIn the baseline model configuration, the wall height (H) was fixed at 6 m, with a toe embedment depth of 0.6 m, as illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The wall width was set at 8.4 m, yielding a (W/H) ratio of 1.4 and the spacing between the two opposing walls was 0 m. Each wall included eight layers of geosynthetic reinforcement, each 4.2 m long (L\u0026thinsp;=\u0026thinsp;0.7H), in accordance with the standard reinforcement length suggested by FHWA guidelines (Berg et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2009\u003c/span\u003e). These reinforcements were anchored to four precast concrete facing panels, each measuring 1.50 m in both width and height.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe foundation soil was modeled to a depth of 6 m, with both the native and reinforced soils treated as homogeneous materials governed by the Mohr-Coulomb failure criterion. The geosynthetic reinforcements, characterized by a tensile stiffness of EA\u0026thinsp;=\u0026thinsp;2500 kN/m, and the panels, which properties are listed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, were modeled as linear elastic behavior.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMaterial properties of concrete panel facing elements (Benmbarek and Djabri 2017)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eModel\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAxial\u003c/p\u003e\u003cp\u003estiffness\u003c/p\u003e\u003cp\u003e(EA) (kN/m)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eFlexural\u003c/p\u003e\u003cp\u003erigidity\u003c/p\u003e\u003cp\u003e(EI)\u003c/p\u003e\u003cp\u003e(kN/m\u003csup\u003e2\u003c/sup\u003e/m)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eThickness\u003c/p\u003e\u003cp\u003e(d)\u003c/p\u003e\u003cp\u003e(m)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eWeight\u003c/p\u003e\u003cp\u003e(Wc)\u003c/p\u003e\u003cp\u003e(kN/ m/m)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003ePoisson ratio\u003c/p\u003e\u003cp\u003e(ν)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eElastic\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e2250\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e4220\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.474\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e3.750\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u003cp\u003e0.2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e summarizes the key geotechnical and mechanical characteristics of the reinforced soils as documented in previous experimental and numerical studies conducted by (Benmbarek and Djabri 2017).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eCharacteristics of the foundation soil, reinforced and retained backfills (Benmbarek and Djabri 2017)\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eProperties\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSymbol\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUnit\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eReinforced soil\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eFoundation soil\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaterial model\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMohr-Coulomb\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMohr-Coulomb\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaterial type\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eDrained\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eDrained\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eUnit weight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eγs\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ekN/m\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e16\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e22\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCohesion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003ec\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ekN/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e100\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003ePoisson\u0026rsquo;s ratio\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eν\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0.3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.3\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eAngle of shearing resistance\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eϕ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003edeg.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e34\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e30\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDilation angle\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eψ\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003edeg.\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDeformation modulus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eE\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003ekN/m\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4x10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e\u003cb\u003e5\u003c/b\u003ex10\u003csup\u003e4\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eThe reinforcement layers and facing elements were installed sequentially alongside the placement of backfill layers. This procedure was repeated for each layer until the full structure was completed. Upon completion of the construction phase, which accounted solely for the self-weight of the backfill, the model was prepared for the application of external static loading.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Geometry of the Models Used in the Comparative Study\u003c/h2\u003e\u003cp\u003eThis paper examines four configurations of reinforcements for closer connected and unconnected BBMSEWs (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The configurations chosen in this study at different arrangements of reinforcement layers was recently selected by other authors read a dynamic analysis of reinforced soil retaining wall (Samee et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2021b\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eIn the first model such as wall A, the opposing walls were connected using continuous integrated strips. In the wall B, eight separate rows of non-overlapping strips were used. For wall C, the lower four reinforcement layers were unconnected and the four upper layers are connected. Conversely, in the wall D, the four upper geosynthetic reinforcements are unconnected, with the lower four strips being connected (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"3 Results and Discussion","content":"\u003cp\u003eThe retaining walls stability was assessed based on four criteria, the external stability was assessed through horizontal wall displacements and overall factor of safety; the internal stability was verified by examining the maximum tensile with as its location (i.e., its distance from the wall facing) in each reinforcement.\u003c/p\u003e\u003cp\u003eThe geosynthetic arrangements were varied under a range of uniform static surcharge loads, increasing from 20 to 100 kN/m\u0026sup2;. The analysis results are presented as graphical profiles illustrating how the response of BBMSEWs varied with different reinforcement arrangements and levels of applied static surcharge loading.\u003c/p\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Horizontal Wall Displacement According to the Reinforcement Arrangement\u003c/h2\u003e\u003cp\u003eThe results evidently show that the maximum horizontal displacement occurs at the Mid-wall when the load is small, i.e. 20kN/m\u003csup\u003e2\u003c/sup\u003e and keep the same position after increasing the surcharge to 100 kN/m\u003csup\u003e2\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe maximum horizontal displacements for all walls were described by curves (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). The numerical results confirmed that wall displacement increases as the value of static surcharge loads on the wall increases. In the other hand, the findings illustrate that the displacements in connected walls, i.e wall A are lower than those in unconnected walls, i.e, wall B; the deformation in connected walls is approximately 50% less than in unconnected walls.\u003c/p\u003e\u003cp\u003eBy comparing wall A with wall B, it was shown that the horizontal wall displacement is lower for a wall A compared to wall B, which gives a greater value, because the reinforcements in it are not connected. Note that the difference between wall A and wall B when q\u0026thinsp;=\u0026thinsp;20 kN/m\u003csup\u003e2\u003c/sup\u003e is about 70%, and the later was found to be 100% when the surcharge was increased five times.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eAlso, when comparing the wall C with wall D, increasing the surcharge from 20 kN/m\u003csup\u003e2\u003c/sup\u003e to 100 kN/m\u003csup\u003e2\u003c/sup\u003e involves an increasing of the maximum wall displacement where the difference is 21% and 40% respectively. It should be noted that in wall C, the four layers at the less half of the wall are unconnected and the four upper strips are connected. Conversely, in the wall D, the four upper strips are unconnected.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e3.2 Factor of Safety\u003c/h2\u003e\u003cp\u003eThe numerical results indicate that the factor of safety (FS) varies depending on the disposition of reinforcement and the load values on each wall (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). The findings confirmed that an increase in the values of the surcharge lead to decrease the factor of safety. As noticed in the case of wall A, in which the reinforcements are all connected, the factor of safety take high values compared with the case in which the reinforcements are unconnected in wall B where Fs have a low values. For example, comparing the wall A with wall B it was found that the decreasing difference is 100% under a surcharge of 100 kN/m\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eAlso, when comparing the wall C with wall D it was found that when the four upper strips are connected and the four strips of the lower half of the walls are unconnected; FS takes larger values that compared to the inverse case, i.e wall D. For example, the value of FS increased from 1.7 to 1.95 under the influence of a load 100 kN/m\u003csup\u003e2\u003c/sup\u003e illustrating that arrangement of reinforcement significantly affects the permanence of BBMSEWs in term of the factor of safety.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.3 Maximum Tension Load Respecting Reinforcement Arrangement\u003c/h2\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e illustrates the curves evolution of maximum reinforcement tensile in reinforcement (Tmax) at which have the same look for all cases. It is also evident that the position and value of Tmax was located in the second line from the base of the wall, with one value was mentioned for wall F under 100 kN/m\u003csup\u003e2\u003c/sup\u003e surcharge load (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003eb).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eMoreover, it is possible to see that wall B presented the greater values of Tmax observed during surcharge application, in which the reinforcements are unconnected and with the differences up to 62.25% in relation to wall A; i.e, connected case.\u003c/p\u003e\u003cp\u003eFurthermore, the load values significantly influences the tensile load in reinforcement, for information, in the wall C case, increasing the surcharge for a five times involves an increase of Tmax about 77.44% (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003eb).\u003c/p\u003e\u003cp\u003eTo judge the effect of the reinforcement distribution, the curves show that wall C presented the small values of Tmax compared to wall D (maximum decreasing difference of 26.93%), indicating that reversed arrangement of reinforcement mainly influences the reinforcement tensile loads.\u003c/p\u003e\u003cp\u003eFurthermore, when comparing the wall A with the wall B, the wall C with the wall D respectively, it was found that where q\u0026thinsp;=\u0026thinsp;20 kN/m\u003csup\u003e2\u003c/sup\u003e the difference is varying 43.13% up to 62.30% respectively; this difference become 14.39% and 26.93% after applying a surcharge of 100 kN/m\u003csup\u003e2\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe potential line of maximum tensile load is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e. It can be seen that at the bottom of the retaining walls, the difference is negligible (except at the top), where the difference is very small. These results indicated that the potential line of maximum tensile load is not as influenced by the disposition of the reinforcement and that it is very close to the line given in the FHWA 2009 guidelines.\u003c/p\u003e\u003c/div\u003e"},{"header":"4 Conclusion","content":"\u003cp\u003eBack-to-back Mechanically Stabilized Earth Walls (BBMSEWs) involve complex geometries and substantial external loads, making it difficult to distinguish between internal and external stability during design and construction. This complexity has prompted growing interest from researchers aiming to better understand the behavior of these systems. Despite existing studies and design guidelines, the behavour of BBMSEWs remains not fully understood and numerical analysis proves to be a valuable tool for enhancing current knowledge in this field.\u003c/p\u003e\u003cp\u003eIn this paper, two-dimensional numerical modelling using a finite element PLAXIS code was carried on the behavour of four closer connected and unconnected BBMSEWs. This research specially examined how the reinforcement disposition affects the stability of these structures and several comparative studies were carried out leading to the following key findings:\u003c/p\u003e\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eThe finite element method demonstrated that horizontal wall displacement increases proportionally with increasing static surcharge load. On the other hand, when the static surcharge loads values increased for five times, the maximum tensile force in reinforcement increased by about 60%.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eMid-wall connections lead to a significant reduction in horizontal displacement by approximately 19% and substantially improve the factor of safety, increasing it from 2 to 7 compared to unconnected walls.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe arrangement of the reinforcement had a significant impact on horizontal wall displacement. In light, when the four strips of the lower half of the wall are connected and the four upper strips are unconnected the maximum displacement was very less than that of in the conversely case. On the contrary, the factor of safety was slowly increased for the same compared walls.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe unconnected walls exhibited slightly higher and more uniform maximum tensile forces compared to the connected walls. Moreover, significant tensile forces were observed in the reinforcements close to the base and occurred at a height of 0.9 m from the bottom of the wall. Furthermore, in the configuration where the lower half of the wall contains four unconnected reinforcement strips and the four upper strips are connected, the maximum tension load is lesser than that of in the conversely case where the four upper strips are unconnected.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eThe potential line of maximum tensile load was not influenced by the reinforcement arrangement at the same at the distribution surcharge load as found in the first part of the study. The lines given in this numerical study was similar at these provide by the FHWA 2009 guidelines.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e\u003cp\u003eThis research offers valuable insights regarding the behavior of BBMSEWs under static loading, enhancing the overall understanding of their performance. However, it does not consider certain factors such as soil compaction and compressible foundation conditions, which may also influence their response behavior. While offering important insights into their static response, it does not account for factors such as soil compaction and compressible foundation conditions. Future research should explore additional parameters under both static and dynamic conditions, including wall height variations, reduced reinforcement lengths, different reinforcement layout and backfill soil types. Additionally, these findings should be validated through physical model testing to ensure practical applicability and reliability.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eH.B. and M.D.: Conceptualization, Methodology, Software, Validation, Formal analysis, Investigation, Writing - Original DraftH. B, M.D., A.B. and A.F.: Conceptualization, Methodology, Validation, Investigation, Writing - Review \u0026amp; Editing, Supervision\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eAttallaoui, S., Benmebarek,S ., Benmebarek, N.: Numerical Analysis of Seismic Response of Back-to-Back Mechanically Stabilized Earth Walls. International review of Civil Engineering, 15 (2024). https://doi.org/10.15866/irece.v15i2.23538\u003c/li\u003e\n \u003cli\u003eAnubhav, S., Basudhar, P. K.: Numerical modelling of surface strip footings resting on double-faced wrap-around vertical reinforced soil walls. Geosynthetics International 18, 21\u0026ndash;34 (2011). https://doi.org/10.1680/gein .2011.18.1.21\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eBalunaini, U., Sravanam, S. M., Madhav, M. R.: Effect of compaction stresses on performance of back-to-back retaining walls. In Proc., 19th Int. Conf. Soil Mechanics and Geotechnical Engineering, edited by Lee,W., Lee, J. S., Kim H. K., Kim D. S, 1951\u0026ndash;1954. London: International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) (2017).\u003c/li\u003e\n \u003cli\u003eBenmebarek, S., Attalaoui, S., Benmebarek, N.: Interaction analysis of back-to-back mechanically stabilized earth walls. Journal of Rock Mechanics and Geotechnical Engineering 8, 697-702 (2016). https://doi.org/10.1016/j.jrmge.2016.05.005\u003c/li\u003e\n \u003cli\u003eBenmebarek, S. and Djabri, M.: FEM to investigate the effect of overlapping-reinforcement on the performance of back-to-back embankment bridge approaches under self-weight. Transportation Geotechnics 11, 17-26 (2017a). https://doi.org/10.1016/j.trgeo.2017.03.002\u003c/li\u003e\n \u003cli\u003eBenmebarek, S., Djabri, M.: FEM analysis of back-to-back mechanically stabilized earth walls under cyclic harmonic loading. Indian Geotechnical Journal 48, 498-509 (2017b). https://doi.org/10.1007/s40098-017-0269-z\u003c/li\u003e\n \u003cli\u003eBerg, R. R., Christopher, B. R., Samtani, N. C.: Design of mechanically stabilized earth walls and reinforced soil slopes, design \u0026amp; construction guidelines, Report No. FHWA-NHI-00-043, 394pp (2009).\u003c/li\u003e\n \u003cli\u003eBrinkgreve, R.B.J.: \u0026quot;Manual for Plaxis 2D\u0026quot; version8, Balkema, Netherlands (1998).\u003c/li\u003e\n \u003cli\u003eChawla, S., Shahu, J.T.: Reinforcement and mud-pumping benefits of geosynthetics in railway tracks: Model Tests. Geotextiles and Geomembranes 44, 366\u0026ndash;80 (2016a). https://doi. org/10.1016/j.geotexmem.2016.01.005\u003c/li\u003e\n \u003cli\u003eChawla, S., Shahu, J.T.: Reinforcement and mud-pumping benefits of geosynthetics in railway tracks: Numerical Analysis. Geotextiles and Geomembranes 44, 344\u0026ndash;57 (2016b). https://doi.org/10.1016/j.geotexmem.2016.01.006\u003c/li\u003e\n \u003cli\u003eChawla, S., Shahu, J.T., Kumar, S.: Analysis of cyclic deformation and post-cyclic strength of reinforced railway tracks on soft subgrade. Transportation Geotechnics 28, 100535 (2021). https://doi.org/10.1016/j.trgeo.2021.100535\u003c/li\u003e\n \u003cli\u003eDjabri, M., Benmebarek, S.: FEM analysis of back-to-back geosynthetic-reinforced soil retaining walls. International Journal of Geosynthetics and Ground Engineering 2, 26 (2016). https://doi.org/10.1007/s40891-016-0067-1\u003c/li\u003e\n \u003cli\u003eDo, N-T., Hoang N.T.: The uncertain free vibration analysis of functionally graded sandwich plates placed on a variable elastic foundation. Latin American Journal of Solids and Structures 22, e8506 (2025). https://doi.org/10.1590/1679-7825/e8506\u003c/li\u003e\n \u003cli\u003eDram, A., Balunaini, U., Benmebarek, S., Sravanam, S.M., Madhav, M.R.: Earthquake response of connected and unconnected back-to-back geosynthetic-reinforced soil walls. International Journal of Geomechanics 21, 1532-3641(2021). https://doi.org/10.1061/(ASCE)GM.1943-5622.0002206\u003c/li\u003e\n \u003cli\u003eEl-Sherbiny, R., Ibrahim, E., Salem, A.: Stability of back-to-back mechanically stabilize earth walls. In: Proceedings of Geo-Congress: Stability and Performance of Slopes and Embankments III. Reston, USA: American Society of Civil Engineers (ASCE), 555e65 (2013). http://dx.doi.org/10.1061/9780784412787.058\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHan, J., Leshchinsky, D.: Analysis of back-to-back mechanically stabilized earth walls. Geotextiles and Geomembranes 28, 262-267 (2010). https://doi.org/10.1016/j.geotexmem.2009.09.012.\u003c/li\u003e\n \u003cli\u003eHardianto, F. S., Truong, K. M.: Seismic deformation of back-to- back mechanically stabilized earth (MSE) walls. In Earth Retention Conf. 3, Geotechnical Special Publication 208, edited by R. Finno, Y. M. A. Hashash, and P. Arduino: 704\u0026ndash;711. Reston, VA: ASCE (2010). https://doi.org/10.1061/41128(384)70\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHazirbaba, K., Mugheida, O., Abu-Lebdeh, G.: A critical review on seismic design of earth-retaining structures. Jordan Journal of Civil Engineering 13, 61-69 (2019).\u003c/li\u003e\n \u003cli\u003eKatkar, B.H., Viswanadham, B.V.S.: Centrifuge Studies on the behavior of back-to-back geogrid reinforced soil walls. Proc. of the Ist Asian Workshop on Physical Modelling in Geotechnics, 14-16, Bombay, India (2012).\u003c/li\u003e\n \u003cli\u003eKhalid, M. H., Alshameri, B.: Determination of safe depth and lateral distance of unsupported excavation near mat foundation in cohesive soils using PLAXIS. Journal of Applied Science and Engineering 25, 249-260 (2021). https://doi.org/10.6180/jase.202204_25(2).0011\u003c/li\u003e\n \u003cli\u003eNajafizadeh, A., Zad, A. A., Yazdi, M.: Experimental evaluation of back-to-back anchored walls by single plate anchors. International Journal of Geomechanics 22, 04022221 (2022). https://doi.org/10.1061/(ASCE)GM.1943-5622.0002470\u003c/li\u003e\n \u003cli\u003eNu, N. T., Van Loi, B., Huong, N. T. T.: An analytical model for residual stress prediction in rebound deformation of the foundation pit. Journal of Applied Science and Engineering 23, 661-668 (2020). https://doi.org/10.6180/jase.202012_23(4).0010\u003c/li\u003e\n \u003cli\u003ePour, M. T., Kalantari, B.: Parametric analysis of back-to-back reinforced earth retaining walls. Pamukkale University. Journal of Engineering Sciences 25, 247-256 (2019). https://doi: 10.5505/pajes.2018.22308\u003c/li\u003e\n \u003cli\u003eRahimi, M., Firoozfar, A., Alielahi, H.: Fragility curves for seismic vulnerability of Back-to-Back mechanically stabilized earth walls. Geotechnical and Geological Engineering 42, 7525-7552 (2024). https://doi.org/10.1007/s10706-024-02938-7\u003c/li\u003e\n \u003cli\u003eRahmouni, O., Belkebir, M., Baazouzi, M., Belhocine, M., Mabrouki, A.: Numerical analysis of back-to-back mechanically stabilized earth walls subjected to dual railroad loadings. International Journal of Geotechnical Engineering 19, 50-61 (2025). https://doi.org/10.1080/19386362.2024.2445845\u003c/li\u003e\n \u003cli\u003eSamee, A. A., Yazdandoust, M., Ghalandarzadeh, A.: Effect of reinforcement arrangement on dynamic behavour of back-to-back mechanically stabilised earth walls. International Journal of Physical Modelling in Geotechnics 22, 1-38 (2021a). https://doi.org/10.1680/jphmg.20.00088\u003c/li\u003e\n \u003cli\u003eSamee, A. A., Yazdandoust, M., Ghalandarzadeh, A.: Performance of back-to-back MSE walls reinforced with steel strips under seismic conditions. Transportation Geotechnics 30, 100540 (2021b). https://doi.org/10.1016/j.trgeo.2021.100540\u003c/li\u003e\n \u003cli\u003eSravanam, S. M., Umashankar, B., Madhira, R.M.: Behavior and design of back-to-back walls considering compaction and surcharge loads. International Journal of Geosynthetics and Ground Engineering 5, 5-31 (2019). https://doi.org/10.1007/s40891-019-0180-z\u003c/li\u003e\n \u003cli\u003eSravanam, S. M., Umashankar, B., Madhira, R.M.: Behavior of connected and unconnected Back-to-Back Walls for Bridge Approaches. International Journal of Geomechanics 20, 06020013 (2020a). https://doi.org/10.1007/s10706-020-01435-x\u003c/li\u003e\n \u003cli\u003eSravanam, S. M., Umashankar, B., Madhira, R.M.: Analysis of single and back-to-back reinforced retaining walls with full-length panel facia. Geotechnical and Geological Engineering 6, 6281-6293 (2020b). https://doi.org/10.1007/s10706-020-01435-x.\u003c/li\u003e\n \u003cli\u003eTatsuoka, F., Tateyama, M., Koseki, J.,Yonezawa, T.: Geosynthetic-reinforced soil structures for railways in Japan. Transportation Infrastructure Geotechnology 1, 3-53 (2014). https://doi.org/10.1007/s40515-013-0001-0\u003c/li\u003e\n \u003cli\u003eWon, M.S., Kim, Y.S.: Internal deformation behavior of geosynthetic-reinforced soil walls. Geotextiles and Geomembranes 25, 10-22 (2007). https://doi.org/10.1016/j.geotexmem.2006.10.001\u003c/li\u003e\n \u003cli\u003eXu , P., Yang , G., Li , T., Hatami, K.: Finite element limit analysis of bearing capacity of footing on back-to-back reinforced soil retaining walls. Transportation Geotechnics 30, 100596 (2021) https://doi.org/10.1016/j.trgeo.2021.100596\u003c/li\u003e\n \u003cli\u003eYazdandoust, M., Daftari, F.: Behavior of back-to-back mechanically stabilized earth walls as railway embankments. Geosynthetics International 31, 785-805 (2024). https://doi.org/10.1680/jgein.23.00126\u003c/li\u003e\n \u003cli\u003eZheng, Y., Li, F., Guo, W., Wang, P., Yang, G.: Influence of facing conditions on the dynamic response of back-to-back MSE walls. Soil Dynamics and Earthquake Engineering 164, 107650 (2023). https://doi.org/10.1016/j.soildyn.2022.107650\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"GRSWalls, Wall displacement, Numerical analysis, Maximum tensile load, Static load","lastPublishedDoi":"10.21203/rs.3.rs-7618712/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7618712/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBack-to-Back Mechanically Stabilized Earth Walls (BBMSEWs) are a frequently form of retaining walls with complex geometry and widely used in numerous geotechnical constructions especially in the bridge approaches. Current design guidelines for BBMSEWs are limited where the Federal Highway Administration recommendations provide a concise overview of the design of this structure. In this paper, the assessment of connected and unconnected closer BBMSEWs under applied static loads was numerically investigated by using two-dimensional finite element analysis. This study deal with the influence of the reinforcement layers and applied static surcharge loads on the behavior of BBMSEWs by analyzing four numerical models of walls with different arrangement of geosynthetic reinforcement under various charge intensity. For the comparison, the factor of safety and the horizontal wall displacement were preferred for external stability, while the maximum tensile load in reinforcement was selected to evaluate internal stability of walls. The most important findings indicate that the arrangement of reinforcement significantly influences the response of BBMSEWs.\u003c/p\u003e","manuscriptTitle":"Numerical Analysis of Closer Back-to-Back Reinforced Soil Walls: Effect of Reinforcement Arrangement","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-30 11:10:06","doi":"10.21203/rs.3.rs-7618712/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9812b498-cbe6-40f2-8be0-b16abd4b6206","owner":[],"postedDate":"September 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T16:12:26+00:00","versionOfRecord":{"articleIdentity":"rs-7618712","link":"https://doi.org/10.1007/s40515-025-00748-9","journal":{"identity":"transportation-infrastructure-geotechnology","isVorOnly":false,"title":"Transportation Infrastructure Geotechnology"},"publishedOn":"2025-11-25 15:58:41","publishedOnDateReadable":"November 25th, 2025"},"versionCreatedAt":"2025-09-30 11:10:06","video":"","vorDoi":"10.1007/s40515-025-00748-9","vorDoiUrl":"https://doi.org/10.1007/s40515-025-00748-9","workflowStages":[]},"version":"v1","identity":"rs-7618712","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7618712","identity":"rs-7618712","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}