Analysis of loess fracture on slope stability based on centrifugal model tests

Abstract

Natural slopes are very common for the complicated topography in the loess area; meanwhile, many artificial slopes were produced by large-scale engineering construction and excavation in recent years. The fractures are widely distributed in the slope, which have a great impact on the slope stability. It is difficult to find out a reasonable method of evaluating the stability of fractured slopes. So, the influence of loess fracture on slope stability was studied by using geotechnical centrifugal testing machine to simulate the process of stress-strain change of slope and systematically studied the influence factors of loess fissure on slope displacement and stress field change, deformation, and failure process. The results show that the displacement of the fractured loess slope is generally larger than that of the integrated loess slope. The difference in vertical displacement of slope edge between the two models is the largest, up to 2 cm. The horizontal displacements of the two models in the slope have a large difference before 1200 s, and the maximum displacement is 1.25 cm. After 1200 s, the difference gradually decreases. There is a great difference in the stress change trend between the two models. The stress in the slope foot, slope top, and slope edge of the fractured slope model has obviously reduced abruptly during the test, and the stress in the integrated loess slope model has little change during the test. It reflects the influence of fractures on the stress distribution of slopes, and the sudden change of stress is a response to the local failure of slopes. The results can provide reference for stability evaluation of fractured loess slopes and the prediction of the risk of loess landslide.