Research on support technology of driving roadway under the influence of continuous fault fracture zone

Research on support technology of driving roadway under the influence of continuous fault fracture zone | 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 Article Research on support technology of driving roadway under the influence of continuous fault fracture zone Li Xin Zhang, Yi Li, Gang Li This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5224498/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract In order to study the support technology of roadway excavation under the influence of multiple fault fracture zones, this paper takes 2101 transport trough of Donggou Coal Mine as the engineering background, and analyzes the surrounding rock variation rules at different stages during roadway excavation under the influence of multiple fault fracture zones through numerical simulation software. The results show that the main factors affecting the surrounding rock are vertical stress and unstable rock mass in the fracture zone. Through numerical simulation, the plastic zone is reduced by 58% after grouting and strengthening support, and the deformation of roof, bottom plate and two sides is reduced by 3.05m, 0.5m and 1.6m respectively. Due to the change of rock stratum caused by fault drop after breaking zone, it is necessary to strengthen the support of roadway roof. After supporting, the plastic zone is reduced by 40%, and the deformation of roof and two sides is reduced by 0.75m. The results of simulation analysis meet the requirements of support and provide a theoretical basis for mine construction. It also provides reference for the excavation of roadway under similar conditions. Earth and environmental sciences/Environmental sciences Physical sciences/Engineering multi-fault fracture zone complex geological conditions fault activation mutual influence of fracture zone Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Introduction Due to large-scale mining, coal resources continue to decrease. Complex geological conditions have an increasingly significant impact on coal mining, in which complex geological structures and high stress coupling bring new challenges to underground roadway support [1-4] . In coal measure strata, fault, fold, collapse column and other geological structures are common bad geological phenomena. When approaching these geological tectonic zones, fracture zones usually form due to strong tectonic stresses. In the crushing area, the crushing deformation such as mesh, leaky roof, continuous sheet wall and large-scale caving [5-9] is usually concurrent, which seriously affects the safety of roadway. Among them, the fault fracture zone has the characteristics of large width, long length and wide influence area, which becomes the difficulty of roadway support. Engineering geology and mining technology are the key factors affecting the control of surrounding rock of roadway [10] . Complex engineering geological conditions are relatively extensive and complex, but high stress is the most important factor for the instability of surrounding rock of roadway [1-4] . Therefore, it is necessary to grasp the law of influence of high stress concentration area generated by fault fracture zone on surrounding rock deformation during roadway opening. It has become the key point of roadway support under complex geological structure conditions. At present, domestic and foreign scholars have carried out extensive research on roadway under the influence of fault structure. Among them, Zhang Haidong [11-14] used FLAC3D to simulate the stress evolution and activation status of F5 reverse fault in Yangcun Coal Mine, and found that the wider the fault zone width, the more easily the fault is activated, and the footwall mining has a greater impact on fault activation [15] . Li Zhihua [16-20] , through the analysis of geological conditions on the 6303 face of Jisan Coal Mine, learned that the roof stability was unstable before the fault in the footwall mining, while the roof stability became worse after the fault in the upper wall mining. Zhong ZL [21] analyzed the results of multiple active strike-slip faults through a three-dimensional numerical model and showed that the fault dislocation amplitude, the distance between adjacent fault planes and other factors would affect the tunnel damage degree. However, Zhong ZL [21] 's research is applicable to the condition that tunnel lining is not suitable for drilling and mining in deep underground areas prone to high stress concentration. In this paper, based on the engineering background of Donggou Coal Mine 2101 transport channel, FLAC3D is used to study the influence law of roadway surrounding rock deformation caused by multiple fault fracture zones at different stages during roadway opening, compare the deformation degree of roadway surrounding rock caused by stress changes, put forward the corresponding roadway support scheme, and demonstrate it based on monitoring data. Engineering background The overall structure of the working face of 2101 is a monoclinal structure with a dip Angle of 3~5°, the average thickness of the coal seam of the working face of 2101 is 6.23m, and the tilt length of the working face is 480m. Fully mechanized top coal caving is adopted, and the working face has three faults F4, F5 and F6, among which F4 is far away from F5 and F6. F5 and F6 faults are separated by 15 m and influence each other. Therefore, the supporting technology of excavation roadway under the influence of continuous fault fracture zone is analyzed by taking 2101 face transportation channelling through F5 normal fault and F6 normal fault as the main research object. 2101 Transport channel: the section shape is trapezoidal section, the upper bottom of the roadway is 4.8m, the lower bottom is 5.8m, the digging height is 3.12m, and the daily support section is steel shed support; According to the geological conditions of the top and bottom strata of the coal seam and the physical parameters of the coal and rock mass at the 2101 working face of Donggou Coal Industry Co., LTD., Table 1 is shown below. Table 1 Numerical simulation of physical and mechanical parameters of coal and rock mass Lithology Density/kg·m -3 Shear modulus/GPa Bulk modulus/GPa Cohesion/MPa Tensile strength /MPa Internal friction angle /° Siltstone 2737 6.6 9.2 8.0 1.7 40 Mudstone 2691 2.8 4.4 3.6 0.9 32 Coal 1421 1.17 3.3 1.6 0.5 25 Limestone 2610 6 8 4.5 3.7 38 Medium sandstone 2719 4.58 6.3 8.2 4.1 40 Fault 1300 0.2 0.1 0.2 0.1 17 Numerical simulation 1. Model Establishment The simplified model is established according to the geological condition and physical parameters of coal and rock mass of Donggou Coal industry 2101 working face. The established model is 480 m long, 50 m wide and 50 m high. Since the working face of 2101 belongs to a near horizontal coal seam, the horizontal coal seam model is established, as shown in Figure 1. 2. Stress change analysis The bottom boundary of the model is fixed, the top of the model is a free boundary, and the displacement constraint is applied in the horizontal direction. The top load is generated by the overlying rock load. According to the buried depth of the roadway, the self-weight stress on the top is 15 MPa, and the initial horizontal stress is 15 MPa. After the initial balance is shown in Figure 2. According to Figure 2: (1) According to the analysis of horizontal stress diagram, the overall horizontal stress is symmetrical, and the horizontal stress is the same under the same burial depth, indicating that the main influence of normal fault is vertical stress. At the same horizontal position, the vertical stress is basically greater than the horizontal stress, which indirectly proves that the maximum principal stress of normal fault is generated by the gravity of overlying strata. (2) According to the vertical stress balance diagram, the vertical normal stress is all compressive stress, and basically maintains the law of gradually increasing with the increase of depth, but the stress distortion is caused by the occurrence of fault zones, which is manifested as a slight decrease in the fault zone; However, the compressive stress on both sides of the fault increased, especially in the overlapping image area of the two faults, the maximum compressive stress exceeded 22 MPa. (3) The horizontal stress along the roadway strike is basically unchanged, while the vertical stress changes greatly. The roof of the roadway with large deep pressure is basically 15.5MPa, and the floor of the roadway is basically 17.0MPa. The internal stress value of the fault decreases, the horizontal stress decreases to 10-12 MPa, and the minimum vertical stress decreases by 10-12 MPa. The stress value between the two adjacent faults increases, which shows that the vertical stress of the roof increases by 2 MPa. The horizontal stress is basically unchanged. According to the analysis, the main attention is paid to the roof and floor failure caused by vertical stress and the influence of unstable surrounding rock on the roadway. The simulated stress after roadway opening is shown in Figure 3: According to Figure 3: After roadway opening, the horizontal stress of the roadway is stable, and the inner fault area drops to 6.2MPa. There are four stress concentration zones on both sides of F5 and F6 faults, the highest being 20 Mpa, and the stress zones are perpendicular to the upper and lower sides of the roadway respectively. In the F5 and F6 fault, the driving roadway is mainly affected by the four stress concentration areas and the unstable rock formation in the fracture zone. 3. Determining the Impact scope The influence range and degree of continuous fault on the roadway can be obtained by numerical simulation of opening deformation on the roof and floor and two walls of the roadway. Since F5 and F6 are unstable fracture zones, it is necessary to determine whether the two sides of the roadway have large deformation due to the crushing of surrounding rock. The deformation curve of the surrounding rock of the excavation roadway is shown in Figure 4: It can be seen from Figure 4: (1) The surrounding rock of the roadway increases in deformation under the influence of faults at 390m; The first peak value is reached at 431m, which is the center of F5 fracture zone. At 451m, it descends to the bottom valley in the high stress concentration area affected by the superposition of continuous faults. It began to rise again 451m later, and reached the second peak at 467m, which was the center of F6 crushing zone. The deformation of section 467-490m decreases by 490m and becomes stable. (2) segmented support analysis ① The deformation of the driving roadway is less than 1m before entering the 425m crushing zone, so it is not necessary to strengthen the support; ②The deformation of 442-460m in the area affected by the superimposed stress of the two faults is less than 1m, so it is not necessary to strengthen the support; ③ The deformation of surrounding rock begins to stabilize after 490m, when the deformation of the roof is much larger than that before the F5 and F6 fracture zones and is greater than 1m, it is necessary to strengthen the support, which is because the properties of the surrounding rock of the two faults with large continuous drop change. The analysis shows that the two fracture zones of the driving roadway section 425-442m and section 460-474m need to be pre-grouting to stabilize the broken surrounding rock, and then strengthen the support to prevent the deformation of the surrounding rock. After 490m, the roof was reinforced to prevent roof deformation. The original support scheme of the remaining excavation section meets the support requirements. Support scheme optimization 1.Pre-grouting in the crushing zone According to the tunnel environment and geological conditions, pre-grouting is carried out at a section 2M away from the fault fracture zone. The length of F5 fault is about 16M, and the grouting is carried out in 8 sections. The length of F6 fault is about 14M, and the grouting is carried out in 7 sections. As shown in Figure 5: According to the buried depth of the roadway, the formula can be used: P=KH: P is the design grouting pressure, MPa; H is the depth of grouting, m; K is the pressure coefficient determined by the grouting depth. The buried depth of this coal seam is around 220m underground. According to the relevant rules of grouting operation and the value table of pressure coefficient at the corresponding depth, the grouting pressure coefficient is set as 0.02 and 4.4MPa is obtained. Affected by factors such as slurry solidification and the redistribution of broken surrounding rock during grouting, there will be a certain amount of slurry loss, and the grouting pressure is finally determined to be 5 MPa. The water-cement ratio of cement grout is 1:0.8 ~ 1:1 (weight ratio), and the ratio of grout to water glass grout is 1:0.3 ~ 1 (volume ratio), which is appropriately adjusted according to the actual geological conditions on site. 2.Crushing belt and reinforced support section In order to facilitate the construction of the crushing belt (after grouting) and strengthen the support section, anchor mesh cable + I-beam shed support is adopted: Figure 6 Section shape is trapezoid. FourΦ20×2200mm left-turned non-longitudinal steel rebar bolts are arranged in each row of the two rows, and the row distance between the bolts is 800mm×800mm. The top row is arranged with 6Φ20×2200mm left-turned non-longitudinal steel rebar bolts, and the row distance between bolts is 800mm×800mm; The top plate is arranged with three Φ17.8×7300mm high-strength and low-relaxation prestressed steel strands, rectangular layout, and the row distance between anchor cables is 1600mm×1600mm. The steel shed adopts 12# I-beam steel shed to shed, and the shed distance is 1000mm. In the actual construction process, the length of the anchor cable should be adjusted according to the investigation of the roof to ensure that the anchoring section is located in the hard rock stratum of the roof to ensure the safety of the roof. Simulated support prediction 1.Vertical stress simulation and prediction Through simulation analysis, the tunnel is mainly affected by four vertical stress concentration areas and unstable rock formation in the crushing zone, so the change of vertical stress before and after roadway support is mainly analyzed: According to Figure 7, the maximum compressive stress extending from the vertical stress on both sides of the roadway to the depth of the two sides after grouting of the broken belt to 20.068 MPa is analyzed. After adding support, the vertical stress on both sides of the roadway almost disappeared, mainly concentrated in the four end corners of the roadway, and the maximum compressive stress was 25.260MPa. According to Figure 8 , it is analyzed that after roadway support optimization after fault, the vertical stress concentration area on both sides of roadway decreases and is slightly away from roadway, and stress concentration area appears at four end angles of roadway, with the maximum value increasing from 25.622 MPa to 27.098 MPa. 2. Plastic zone simulation and prediction It can be seen from Figure 9 that the plastic zone in the crushing zone is significantly reduced by 30% after pre-grouting, and stable rock mass is formed around the roadway to protect the roadway. The plastic zone in the crushing zone is reduced by 40% after strengthening the support. It can be seen from Figure 10 that the plastic zone of 474m-580m section is significantly reduced by 45% after strengthening the support. The fracture area and reinforced support section are obviously reduced after grouting and support respectively, and the predicted support scheme is effective to simulate. 3. Deformation simulation and prediction As can be seen from Figure 11: After simulated grouting of the crushing belt, the maximum deformation of the top and bottom plates and the two sides are reduced by 1.5m, 0.3m and 0.6m respectively. It is verified that the pre-grouting of the crushing zone is effective for the stability of the roadway surrounding rock. Based on pre-grouting, the maximum deformation of the top and bottom plate and the two sides of the crushing belt is reduced by 1.55m, 0.2m and 1m respectively after the support simulation of the crushing belt and the reinforced support section. The deformation of roadway roof in the reinforced support section is reduced by 0.75m, and all of them are less than 1m. It is predicted that strengthening support scheme can effectively prevent and control the deformation of roadway surrounding rock. Data monitoring According to the completion of site construction, monitoring points are set at the top and bottom of four sections and two sides of the roadway 400m (no normal fault is encountered in section 1), 430m (normal fault fracture zone in section 2), 450m (mutual influence zone between two normal faults in section 3), and 500m (after the surrounding rock of F5 and F6 faults in section 4 is stable and changed), respectively. The deformation distance /m from 1 to 6 months after the completion of construction is monitored to judge the supporting effect. According to the monitoring data, FIgure 12 shows that the roadway is stable after segmented support through the F5 and F6 fault fracture zones, and the supporting effect can reach the theoretical value, and the supporting effect is good. Conclusion Through the simulation analysis of the supporting section and field testing, the support optimization of the transportation roadway of 2101 face in Donggou Coal Mine has changed the stress position of the roadway, reducing the plastic zone of the crushing zone by 58% and the plastic zone of the supporting section by 45%, effectively controlling the deformation of the roadway surrounding rock and providing a guarantee for the safety of coal mine production. It also provides reference for the excavation of similar coal mines. Declarations Author Contribution Prof. Lixin Zhang provided the data and project, Dr. Yi Li wrote the first draft and determined the research methodology, and Prof. Gang Li provided the research funding. Prof. Lixin Zhang and Prof. Gang Li supervised Dr. Yi Li to revise the first draft. Data Availability All data generated or analysed during this study are included in this published article [and its supplementary information files]. References Li Guichen; Yang Sen; Sun Yuantian; Xu Jiahui; Li Jinghua. Research progress of roadway surrounding rock control technology under complex conditions [J]. Coal Science and Technology, 202:17. Kang Hongpu, Feng Zhiqiang. Current situation and development trend of grouting reinforcement technology for roadway surrounding rock in Coal mine [J]. Coal Mining,2013:7-13. Wang Xiaoqing, Kang Hongpu, Gao Fuqiang. Analysis of pressure arch formation and bolt action in gravel anchoring [J]. Journal of China Coal Society,2020 LI Gui-Chen1,2, Yang Sen, Sun Yuan-tian, XU Jia-hui, LI Jing-hua. Research progress of roadway surrounding rock control technology under complex conditions [J]. Coal Science and Technology,:,2022.50 Chen Xiaoxiang, Wu Junpeng. Study on mechanism and control technology of large deformation of roadway surrounding rock in fault fracture zone [J]. Journal of Mining and Safety Engineering,2018:13-20. Wang Xiangyu, Bai Jianbiao, Li Lei. Research on deformation and failure mechanism and control technology of near-fault mining roadway [J]. Journal of Mining and Safety Engineering,2014:14-20. LIU Quansheng, Zhang Hua, Lin Tao. Surrounding rock stability and support measures for deep coal mine roadway [J]. Chinese Journal of Rock Mechanics and Engineering,2004:171-176. Zhao Yixin, Jiang Yaodong, Meng Lei. Application of grouting support technology in advanced pipe shed in extremely complex fault zone [J]. Journal of Mining and Safety Engineering,2013:108-112. LIU Kaide, Liu Quansheng, Liu Bin. Study on countermeasures and effects of roadway stability control in geological anomaly zone [J]. Chinese Journal of Rock Mechanics and Engineering,2011:115-126. Wang Jinhua, Kang Hongpu, Gao Fuqiang. Numerical simulation of force transfer mechanism and stress distribution of anchor cable support [J]. Journal of China Coal Society,2008:5-10. Zhang Haidong. Simulation study on the influence of fault fracture zone width on the activation rule of reverse fault [J]. Coal Engineering,2018,50(01):96-99+104. Wang Enying, Shao Qiang, Du Yunkuan. Genetic mechanism and distribution of coal in Liangpan structure of reverse fault [J]. Mining Safety and Environmental Protection,2010:6+10-12. Sun Zongqi, Zhang Jinghe1 Changes of ground stress before and after the occurrence of geological fault structures [J]. Chinese Journal of Rock Mechanics and Engineering, 2004 (23) Wang Enying, Shao Qiang, Han Songlin. Mechanical analysis of normal fault formation and its control on structural coal [J]. Coal Science and Technology, 2009,37 (09) The relationship of displacement length of normal faults and its significance [J]. Earth Science Frontiers,2004:247-256. Wu Xiang, Zhao Quanfu, Wan Bin. Study on occurrence rule of small dip normal faults in Daizhuang mine field [J]. Coal Science and Technology,2005:62-64. Zhang Wenxi, Wei Yanlong, Pan Fan. Mine pressure law during normal faults of fully mechanized mining face [J]. Coal Mine Safety,2016:210-213. Tian Zhaochuan. Safety technology practice of normal fault crossing in Fully mechanized caving face [J]. Shandong Coal Science and Technology, 202:3. LI Zhihua, Dou Linming, Lu Zhenyu, et al. Study on fault slip instability induced by mining [J]. Journal of Mining and Safety Engineering Zheng Y,Wu K,Jiang Y J,et al. Optimization and design of pre-reinforcement for a subsea tunnel crossing a fault fracture zone[J]. Marine Georesources & Geotechnology,2023,41(1). Zhong Z L,Zhen W,Mi Z,et al. Structural damage assessment of mountain tunnels in fault fracture zone subjected to multiple strike-slip fault movement[J]. Tunnelling and Underground Space Technology incorporating Trenchless Technology Research, 2020104 (in Chinese). 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Reinforced support after section 490m\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/ae6b51491bb223ecaddae372.png"},{"id":70341174,"identity":"992da473-da58-4d55-92a5-d675da0f0cac","added_by":"auto","created_at":"2024-12-02 10:03:02","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":82898,"visible":true,"origin":"","legend":"\u003cp\u003eChanges of plastic zone before and after grouting and support\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/6feb0e02029b8f2e306af37c.png"},{"id":70341179,"identity":"0dc63c2f-2b54-46dc-878f-87828cf82c08","added_by":"auto","created_at":"2024-12-02 10:03:04","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":56681,"visible":true,"origin":"","legend":"\u003cp\u003eDeformation curve of roadway surrounding rock before and after grouting and support\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/2f0bdceb7745a5e8db7cd5c8.png"},{"id":70340574,"identity":"cb576bdf-1a86-451a-b207-d4f3b2dbdd69","added_by":"auto","created_at":"2024-12-02 09:55:03","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":64759,"visible":true,"origin":"","legend":"\u003cp\u003e(a) No reinforced support after section 490m Figure 10 (b) Reinforced support after section 490m\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/a328f9e53b224198744050ca.png"},{"id":70340561,"identity":"d63dac52-d104-4155-913b-b45994f066c3","added_by":"auto","created_at":"2024-12-02 09:55:01","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":91418,"visible":true,"origin":"","legend":"\u003cp\u003eMigration data of surrounding rock in four sections six months after construction\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/3658c6e1522d04f5ad8abf84.png"},{"id":84865239,"identity":"d284f69b-cec6-449d-84ca-54f774247506","added_by":"auto","created_at":"2025-06-18 08:02:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1518054,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/0b6d8e25-f9cb-4c3b-8620-c2c4a7d34102.pdf"},{"id":70340615,"identity":"bba5bd33-e778-4a02-9a08-60b5af196871","added_by":"auto","created_at":"2024-12-02 09:55:10","extension":"rar","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":2647423,"visible":true,"origin":"","legend":"","description":"","filename":"Relevantexperimentaldata.rar","url":"https://assets-eu.researchsquare.com/files/rs-5224498/v1/246fb52d8084f82ece540e1c.rar"}],"financialInterests":"No competing interests reported.","formattedTitle":"Research on support technology of driving roadway under the influence of continuous fault fracture zone","fulltext":[{"header":"Introduction","content":"\u003cp\u003eDue to large-scale mining, coal resources continue to decrease. Complex geological conditions have an increasingly significant impact on coal mining, in which complex geological structures and high stress coupling bring new challenges to underground roadway support \u003csup\u003e[1-4]\u003c/sup\u003e. In coal measure strata, fault, fold, collapse column and other geological structures are common bad geological phenomena. When approaching these geological tectonic zones, fracture zones usually form due to strong tectonic stresses. In the crushing area, the crushing deformation such as mesh, leaky roof, continuous sheet wall and large-scale caving\u003csup\u003e\u0026nbsp;[5-9]\u003c/sup\u003e is usually concurrent, which seriously affects the safety of roadway. Among them, the fault fracture zone has the characteristics of large width, long length and wide influence area, which becomes the difficulty of roadway support.\u003c/p\u003e\n\u003cp\u003eEngineering geology and mining technology are the key factors affecting the control of surrounding rock of roadway\u003csup\u003e\u0026nbsp;[10]\u003c/sup\u003e. Complex engineering geological conditions are relatively extensive and complex, but high stress is the most important factor for the instability of surrounding rock of roadway\u003csup\u003e\u0026nbsp;[1-4]\u003c/sup\u003e. Therefore, it is necessary to grasp the law of influence of high stress concentration area generated by fault fracture zone on surrounding rock deformation during roadway opening. It has become the key point of roadway support under complex geological structure conditions.\u003c/p\u003e\n\u003cp\u003eAt present, domestic and foreign scholars have carried out extensive research on roadway under the influence of fault structure. Among them, Zhang Haidong\u003csup\u003e[11-14]\u003c/sup\u003e used FLAC3D to simulate the stress evolution and activation status of F5 reverse fault in Yangcun Coal Mine, and found that the wider the fault zone width, the more easily the fault is activated, and the footwall mining has a greater impact on fault activation\u003csup\u003e\u0026nbsp;[15]\u003c/sup\u003e. Li Zhihua\u003csup\u003e[16-20]\u003c/sup\u003e, through the analysis of geological conditions on the 6303 face of Jisan Coal Mine, learned that the roof stability was unstable before the fault in the footwall mining, while the roof stability became worse after the fault in the upper wall mining. Zhong ZL\u003csup\u003e[21]\u003c/sup\u003e analyzed the results of multiple active strike-slip faults through a three-dimensional numerical model and showed that the fault dislocation amplitude, the distance between adjacent fault planes and other factors would affect the tunnel damage degree. However, Zhong ZL \u003csup\u003e[21]\u003c/sup\u003e 's research is applicable to the condition that tunnel lining is not suitable for drilling and mining in deep underground areas prone to high stress concentration.\u003c/p\u003e\n\u003cp\u003eIn this paper, based on the engineering background of Donggou Coal Mine 2101 transport channel, FLAC3D is used to study the influence law of roadway surrounding rock deformation caused by multiple fault fracture zones at different stages during roadway opening, compare the deformation degree of roadway surrounding rock caused by stress changes, put forward the corresponding roadway support scheme, and demonstrate it based on monitoring data.\u003c/p\u003e\n\n\n\n\n\n\n\n\n\n\n\n\n\n"},{"header":"Engineering background","content":"\u003cp\u003eThe overall structure of the working face of 2101 is a monoclinal structure with a dip Angle of 3~5°, the average thickness of the coal seam of the working face of 2101 is 6.23m, and the tilt length of the working face is 480m. Fully mechanized top coal caving is adopted, and the working face has three faults F4, F5 and F6, among which F4 is far away from F5 and F6. F5 and F6 faults are separated by 15 m and influence each other. Therefore, the supporting technology of excavation roadway under the influence of continuous fault fracture zone is analyzed by taking 2101 face transportation channelling through F5 normal fault and F6 normal fault as the main research object.\u003c/p\u003e\u003cp\u003e2101 Transport channel: the section shape is trapezoidal section, the upper bottom of the roadway is 4.8m, the lower bottom is 5.8m, the digging height is 3.12m, and the daily support section is steel shed support; According to the geological conditions of the top and bottom strata of the coal seam and the physical parameters of the coal and rock mass at the 2101 working face of Donggou Coal Industry Co., LTD., Table 1 is shown below.\u003c/p\u003e\u003cp\u003eTable 1 Numerical simulation of physical and mechanical parameters of coal and rock mass\u003c/p\u003e\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"643\"\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eLithology\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003eDensity/kg·m\u003csup\u003e-3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003eShear modulus/GPa\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003eBulk modulus/GPa\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003eCohesion/MPa\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003eTensile strength /MPa\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003eInternal friction angle /°\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eSiltstone\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e2737\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003e6.6\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003e9.2\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e8.0\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003e1.7\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eMudstone\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e2691\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003e2.8\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003e4.4\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e3.6\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003e0.9\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003e32\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eCoal\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e1421\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003e1.17\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003e3.3\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e1.6\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003e0.5\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eLimestone\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e2610\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e4.5\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003e3.7\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eMedium sandstone\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e2719\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003e4.58\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003e6.3\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e8.2\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003e4.1\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd valign=\"top\" style=\"width: 19.1291%;\"\u003e\n \u003cp\u003eFault\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e1300\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.1524%;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.93%;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 10.5754%;\"\u003e\n \u003cp\u003e0.2\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 14.619%;\"\u003e\n \u003cp\u003e0.1\u003c/p\u003e\n \u003c/td\u003e\u003ctd valign=\"top\" style=\"width: 16.0187%;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e"},{"header":"Numerical simulation","content":"\u003cp\u003e\u003cstrong\u003e1. Model Establishment\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eThe simplified model is established according to the geological condition and physical parameters of coal and rock mass of Donggou Coal industry 2101 working face. The established model is 480 m long, 50 m wide and 50 m high. Since the working face of 2101 belongs to a near horizontal coal seam, the horizontal coal seam model is established, as shown in Figure 1.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e2. Stress change analysis\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eThe bottom boundary of the model is fixed, the top of the model is a free boundary, and the displacement constraint is applied in the horizontal direction. The top load is generated by the overlying rock load. According to the buried depth of the roadway, the self-weight stress on the top is 15 MPa, and the initial horizontal stress is 15 MPa. After the initial balance is shown in Figure 2.\u003c/p\u003e\u003cp\u003eAccording to Figure 2:\u003c/p\u003e\u003cp\u003e(1) According to the analysis of horizontal stress diagram, the overall horizontal stress is symmetrical, and the horizontal stress is the same under the same burial depth, indicating that the main influence of normal fault is vertical stress. At the same horizontal position, the vertical stress is basically greater than the horizontal stress, which indirectly proves that the maximum principal stress of normal fault is generated by the gravity of overlying strata.\u003c/p\u003e\u003cp\u003e(2) According to the vertical stress balance diagram, the vertical normal stress is all compressive stress, and basically maintains the law of gradually increasing with the increase of depth, but the stress distortion is caused by the occurrence of fault zones, which is manifested as a slight decrease in the fault zone; However, the compressive stress on both sides of the fault increased, especially in the overlapping image area of the two faults, the maximum compressive stress exceeded 22 MPa.\u003c/p\u003e\u003cp\u003e(3) The horizontal stress along the roadway strike is basically unchanged, while the vertical stress changes greatly. The roof of the roadway with large deep pressure is basically 15.5MPa, and the floor of the roadway is basically 17.0MPa. The internal stress value of the fault decreases, the horizontal stress decreases to 10-12 MPa, and the minimum vertical stress decreases by 10-12 MPa. The stress value between the two adjacent faults increases, which shows that the vertical stress of the roof increases by 2 MPa. The horizontal stress is basically unchanged.\u003c/p\u003e\u003cp\u003eAccording to the analysis, the main attention is paid to the roof and floor failure caused by vertical stress and the influence of unstable surrounding rock on the roadway. The simulated stress after roadway opening is shown in Figure 3:\u003c/p\u003e\u003cp\u003eAccording to Figure 3:\u003c/p\u003e\u003cp\u003eAfter roadway opening, the horizontal stress of the roadway is stable, and the inner fault area drops to 6.2MPa. There are four stress concentration zones on both sides of F5 and F6 faults, the highest being 20 Mpa, and the stress zones are perpendicular to the upper and lower sides of the roadway respectively. In the F5 and F6 fault, the driving roadway is mainly affected by the four stress concentration areas and the unstable rock formation in the fracture zone.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e3. Determining the Impact scope\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eThe influence range and degree of continuous fault on the roadway can be obtained by numerical simulation of opening deformation on the roof and floor and two walls of the roadway. Since F5 and F6 are unstable fracture zones, it is necessary to determine whether the two sides of the roadway have large deformation due to the crushing of surrounding rock. The deformation curve of the surrounding rock of the excavation roadway is shown in Figure 4:\u003c/p\u003e\u003cp\u003eIt can be seen from Figure 4:\u003c/p\u003e\u003cp\u003e(1) The surrounding rock of the roadway increases in deformation under the influence of faults at 390m; The first peak value is reached at 431m, which is the center of F5 fracture zone. At 451m, it descends to the bottom valley in the high stress concentration area affected by the superposition of continuous faults. It began to rise again 451m later, and reached the second peak at 467m, which was the center of F6 crushing zone. The deformation of section 467-490m decreases by 490m and becomes stable.\u003c/p\u003e\u003cp\u003e(2) segmented support analysis\u003c/p\u003e\u003cp\u003e①\u0026nbsp;The deformation of the driving roadway is less than 1m before entering the 425m crushing zone, so it is not necessary to strengthen the support;\u003c/p\u003e\u003cp\u003e②The deformation of 442-460m in the area affected by the superimposed stress of the two faults is less than 1m, so it is not necessary to strengthen the support;\u003c/p\u003e\u003cp\u003e③\u0026nbsp;The deformation of surrounding rock begins to stabilize after 490m, when the deformation of the roof is much larger than that before the F5 and F6 fracture zones and is greater than 1m, it is necessary to strengthen the support, which is because the properties of the surrounding rock of the two faults with large continuous drop change.\u003c/p\u003e\u003cp\u003eThe analysis shows that the two fracture zones of the driving roadway section 425-442m and section 460-474m need to be pre-grouting to stabilize the broken surrounding rock, and then strengthen the support to prevent the deformation of the surrounding rock. After 490m, the roof was reinforced to prevent roof deformation. The original support scheme of the remaining excavation section meets the support requirements.\u003c/p\u003e"},{"header":"Support scheme optimization","content":"\u003cp\u003e\u003cstrong\u003e1.Pre-grouting in the crushing zone\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAccording to the tunnel environment and geological conditions, pre-grouting is carried out at a section 2M away from the fault fracture zone. The length of F5 fault is about 16M, and the grouting is carried out in 8 sections. The length of F6 fault is about 14M, and the grouting is carried out in 7 sections. As shown in Figure 5:\u003c/p\u003e\u003cp\u003eAccording to the buried depth of the roadway, the formula can be used: P=KH:\u003c/p\u003e\u003cp\u003eP is the design grouting pressure, MPa;\u003c/p\u003e\u003cp\u003eH is the depth of grouting, m;\u003c/p\u003e\u003cp\u003eK is the pressure coefficient determined by the grouting depth.\u003c/p\u003e\u003cp\u003eThe buried depth of this coal seam is around 220m underground. According to the relevant rules of grouting operation and the value table of pressure coefficient at the corresponding depth, the grouting pressure coefficient is set as 0.02 and 4.4MPa is obtained. Affected by factors such as slurry solidification and the redistribution of broken surrounding rock during grouting, there will be a certain amount of slurry loss, and the grouting pressure is finally determined to be 5 MPa.\u003c/p\u003e\u003cp\u003eThe water-cement ratio of cement grout is 1:0.8 ~ 1:1 (weight ratio), and the ratio of grout to water glass grout is 1:0.3 ~ 1 (volume ratio), which is appropriately adjusted according to the actual geological conditions on site.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e2.Crushing belt and reinforced support section\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eIn order to facilitate the construction of the crushing belt (after grouting) and strengthen the support section, anchor mesh cable + I-beam shed support is adopted:\u003c/p\u003e\u003cp\u003eFigure 6 Section shape is trapezoid. FourΦ20×2200mm left-turned non-longitudinal steel rebar bolts are arranged in each row of the two rows, and the row distance between the bolts is 800mm×800mm. The top row is arranged with 6Φ20×2200mm left-turned non-longitudinal steel rebar bolts, and the row distance between bolts is 800mm×800mm; The top plate is arranged with three\u0026nbsp;Φ17.8×7300mm high-strength and low-relaxation prestressed steel strands, rectangular layout, and the row distance between anchor cables is 1600mm×1600mm. The steel shed adopts 12# I-beam steel shed to shed, and the shed distance is 1000mm. In the actual construction process, the length of the anchor cable should be adjusted according to the investigation of the roof to ensure that the anchoring section is located in the hard rock stratum of the roof to ensure the safety of the roof.\u003c/p\u003e"},{"header":"Simulated support prediction","content":"\u003cp\u003e\u003cstrong\u003e1.Vertical stress simulation and prediction\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eThrough simulation analysis, the tunnel is mainly affected by four vertical stress concentration areas and unstable rock formation in the crushing zone, so the change of vertical stress before and after roadway support is mainly analyzed:\u003c/p\u003e\u003cp\u003eAccording to Figure 7, the maximum compressive stress extending from the vertical stress on both sides of the roadway to the depth of the two sides after grouting of the broken belt to 20.068 MPa is analyzed. After adding support, the vertical stress on both sides of the roadway almost disappeared, mainly concentrated in the four end corners of the roadway, and the maximum compressive stress was 25.260MPa.\u003c/p\u003e\u003cp\u003eAccording to\u0026nbsp;Figure 8\u0026nbsp;, it is analyzed that after roadway support optimization after fault, the vertical stress concentration area on both sides of roadway decreases and is slightly away from roadway, and stress concentration area appears at four end angles of roadway, with the maximum value increasing from 25.622 MPa to 27.098 MPa.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e2. Plastic zone simulation and prediction\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eIt can be seen from Figure 9 that the plastic zone in the crushing zone is significantly reduced by 30% after pre-grouting, and stable rock mass is formed around the roadway to protect the roadway. The plastic zone in the crushing zone is reduced by 40% after strengthening the support.\u0026nbsp;\u003c/p\u003e\u003cp\u003eIt can be seen from Figure 10 that the plastic zone of 474m-580m section is significantly reduced by 45% after strengthening the support. The fracture area and reinforced support section are obviously reduced after grouting and support respectively, and the predicted support scheme is effective to simulate.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e3. Deformation simulation and prediction\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAs can be seen from Figure 11:\u003c/p\u003e\u003cp\u003eAfter simulated grouting of the crushing belt, the maximum deformation of the top and bottom plates and the two sides are reduced by 1.5m, 0.3m and 0.6m respectively. It is verified that the pre-grouting of the crushing zone is effective for the stability of the roadway surrounding rock.\u003c/p\u003e\u003cp\u003eBased on pre-grouting, the maximum deformation of the top and bottom plate and the two sides of the crushing belt is reduced by 1.55m, 0.2m and 1m respectively after the support simulation of the crushing belt and the reinforced support section. The deformation of roadway roof in the reinforced support section is reduced by 0.75m, and all of them are less than 1m. It is predicted that strengthening support scheme can effectively prevent and control the deformation of roadway surrounding rock.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eData monitoring\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAccording to the completion of site construction, monitoring points are set at the top and bottom of four sections and two sides of the roadway 400m (no normal fault is encountered in section 1), 430m (normal fault fracture zone in section 2), 450m (mutual influence zone between two normal faults in section 3), and 500m (after the surrounding rock of F5 and F6 faults in section 4 is stable and changed), respectively. The deformation distance /m from 1 to 6 months after the completion of construction is monitored to judge the supporting effect.\u003c/p\u003e\u003cp\u003eAccording to the monitoring data, FIgure 12 shows that the roadway is stable after segmented support through the F5 and F6 fault fracture zones, and the supporting effect can reach the theoretical value, and the supporting effect is good.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThrough the simulation analysis of the supporting section and field testing, the support optimization of the transportation roadway of 2101 face in Donggou Coal Mine has changed the stress position of the roadway, reducing the plastic zone of the crushing zone by 58% and the plastic zone of the supporting section by 45%, effectively controlling the deformation of the roadway surrounding rock and providing a guarantee for the safety of coal mine production. It also provides reference for the excavation of similar coal mines.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eProf. Lixin Zhang provided the data and project, Dr. Yi Li wrote the first draft and determined the research methodology, and Prof. Gang Li provided the research funding. Prof. Lixin Zhang and Prof. Gang Li supervised Dr. Yi Li to revise the first draft.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data generated or analysed during this study are included in this published article [and its supplementary information files].\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLi Guichen; Yang Sen; Sun Yuantian; Xu Jiahui; Li Jinghua. Research progress of roadway surrounding rock control technology under complex conditions [J]. Coal Science and Technology, 202:17.\u003c/li\u003e\n\u003cli\u003eKang Hongpu, Feng Zhiqiang. Current situation and development trend of grouting reinforcement technology for roadway surrounding rock in Coal mine [J]. Coal Mining,2013:7-13.\u003c/li\u003e\n\u003cli\u003eWang Xiaoqing, Kang Hongpu, Gao Fuqiang. Analysis of pressure arch formation and bolt action in gravel anchoring [J]. Journal of China Coal Society,2020 \u003c/li\u003e\n\u003cli\u003eLI Gui-Chen1,2, Yang Sen, Sun Yuan-tian, XU Jia-hui, LI Jing-hua. Research progress of roadway surrounding rock control technology under complex conditions [J]. Coal Science and Technology,:,2022.50 \u003c/li\u003e\n\u003cli\u003eChen Xiaoxiang, Wu Junpeng. Study on mechanism and control technology of large deformation of roadway surrounding rock in fault fracture zone [J]. Journal of Mining and Safety Engineering,2018:13-20.\u003c/li\u003e\n\u003cli\u003eWang Xiangyu, Bai Jianbiao, Li Lei. Research on deformation and failure mechanism and control technology of near-fault mining roadway [J]. Journal of Mining and Safety Engineering,2014:14-20. \u003c/li\u003e\n\u003cli\u003eLIU Quansheng, Zhang Hua, Lin Tao. Surrounding rock stability and support measures for deep coal mine roadway [J]. Chinese Journal of Rock Mechanics and Engineering,2004:171-176.\u003c/li\u003e\n\u003cli\u003eZhao Yixin, Jiang Yaodong, Meng Lei. Application of grouting support technology in advanced pipe shed in extremely complex fault zone [J]. Journal of Mining and Safety Engineering,2013:108-112.\u003c/li\u003e\n\u003cli\u003eLIU Kaide, Liu Quansheng, Liu Bin. Study on countermeasures and effects of roadway stability control in geological anomaly zone [J]. Chinese Journal of Rock Mechanics and Engineering,2011:115-126.\u003c/li\u003e\n\u003cli\u003eWang Jinhua, Kang Hongpu, Gao Fuqiang. Numerical simulation of force transfer mechanism and stress distribution of anchor cable support [J]. Journal of China Coal Society,2008:5-10.\u003c/li\u003e\n\u003cli\u003eZhang Haidong. Simulation study on the influence of fault fracture zone width on the activation rule of reverse fault [J]. Coal Engineering,2018,50(01):96-99+104.\u003c/li\u003e\n\u003cli\u003eWang Enying, Shao Qiang, Du Yunkuan. Genetic mechanism and distribution of coal in Liangpan structure of reverse fault [J]. Mining Safety and Environmental Protection,2010:6+10-12.\u003c/li\u003e\n\u003cli\u003eSun Zongqi, Zhang Jinghe1 Changes of ground stress before and after the occurrence of geological fault structures [J]. Chinese Journal of Rock Mechanics and Engineering, 2004 (23)\u003c/li\u003e\n\u003cli\u003eWang Enying, Shao Qiang, Han Songlin. Mechanical analysis of normal fault formation and its control on structural coal [J]. Coal Science and Technology, 2009,37 (09)\u003c/li\u003e\n\u003cli\u003eThe relationship of displacement length of normal faults and its significance [J]. Earth Science Frontiers,2004:247-256.\u003c/li\u003e\n\u003cli\u003eWu Xiang, Zhao Quanfu, Wan Bin. Study on occurrence rule of small dip normal faults in Daizhuang mine field [J]. Coal Science and Technology,2005:62-64.\u003c/li\u003e\n\u003cli\u003eZhang Wenxi, Wei Yanlong, Pan Fan. Mine pressure law during normal faults of fully mechanized mining face [J]. Coal Mine Safety,2016:210-213.\u003c/li\u003e\n\u003cli\u003eTian Zhaochuan. Safety technology practice of normal fault crossing in Fully mechanized caving face [J]. Shandong Coal Science and Technology, 202:3.\u003c/li\u003e\n\u003cli\u003eLI Zhihua, Dou Linming, Lu Zhenyu, et al. Study on fault slip instability induced by mining [J]. Journal of Mining and Safety Engineering \u003c/li\u003e\n\u003cli\u003eZheng Y,Wu K,Jiang Y J,et al. Optimization and design of pre-reinforcement for a subsea tunnel crossing a fault fracture zone[J]. Marine Georesources \u0026amp; Geotechnology,2023,41(1).\u003c/li\u003e\n\u003cli\u003eZhong Z L,Zhen W,Mi Z,et al. Structural damage assessment of mountain tunnels in fault fracture zone subjected to multiple strike-slip fault movement[J]. Tunnelling and Underground Space Technology incorporating Trenchless Technology Research, 2020104 (in Chinese).\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"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":"multi-fault fracture zone, complex geological conditions, fault activation, mutual influence of fracture zone","lastPublishedDoi":"10.21203/rs.3.rs-5224498/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5224498/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"In order to study the support technology of roadway excavation under the influence of multiple fault fracture zones, this paper takes 2101 transport trough of Donggou Coal Mine as the engineering background, and analyzes the surrounding rock variation rules at different stages during roadway excavation under the influence of multiple fault fracture zones through numerical simulation software. The results show that the main factors affecting the surrounding rock are vertical stress and unstable rock mass in the fracture zone. Through numerical simulation, the plastic zone is reduced by 58% after grouting and strengthening support, and the deformation of roof, bottom plate and two sides is reduced by 3.05m, 0.5m and 1.6m respectively. Due to the change of rock stratum caused by fault drop after breaking zone, it is necessary to strengthen the support of roadway roof. After supporting, the plastic zone is reduced by 40%, and the deformation of roof and two sides is reduced by 0.75m. The results of simulation analysis meet the requirements of support and provide a theoretical basis for mine construction. It also provides reference for the excavation of roadway under similar conditions.","manuscriptTitle":"Research on support technology of driving roadway under the influence of continuous fault fracture zone","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-12-02 09:53:57","doi":"10.21203/rs.3.rs-5224498/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":"70fd52b8-9b38-4553-be20-044edfc70d04","owner":[],"postedDate":"December 2nd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":40539903,"name":"Earth and environmental sciences/Environmental sciences"},{"id":40539904,"name":"Physical sciences/Engineering"}],"tags":[],"updatedAt":"2025-06-18T07:53:58+00:00","versionOfRecord":[],"versionCreatedAt":"2024-12-02 09:53:57","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5224498","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5224498","identity":"rs-5224498","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}