A Case Study of Using Numerical Analysis to Assess Slope Stability of National Highways in Northern Taiwan

Because of its location at the meeting point of the Eurasian Plate and the Philippine Sea Plate, Taiwan experiences earthquakes frequently. Mountains and hills make up the majority of the landscape, and Taiwan has some of the highest precipitation levels in the world. The stability of slopes in different parts of Taiwan is influenced by all of these factors. The study's instances are the National Freeway 1 and 5 slopes, where several landslide and rockfall incidents have occurred. This study used PLAXIS 2D CE finite element software to simulate and analyze the safety of highway slope protection projects. Displacements induced by normal and high groundwater levels were discussed. Moreover, a pseudo-static study of slope displacements under seismic conditions was performed. According to the results of the numerical study, the force operating on the slope was centered on the sliding surface when the groundwater level was normal, and it extended to the top when the groundwater level was high. By comparison, under seismic conditions, the force acting on the slope extended to the whole slope.