Study On The Stability Of Bedded Rock Slope Due To Rainfall Infiltration

As rapid development of China’s economy and implementation of the large-scale development strategy for the western region, high speed railway construction develops very rapidly in southwest China. However, a large quantity of embankment slopes and cutting slopes have boomed along railway due to complicated terrain and geological conditions and the necessary of construction during construction of high speed railway in southwest China. The bedded rock slope is one of the familiar types of slopes along railway. The frequent occurrence of bedding landslide induced by rainfall is a big hazard to the construction and operation of high speed railway. Thus it has significant practical meaning to carry on the research on the stability of bedded rock slope due to rainfall infiltration. Based on K307work site, this paper conducts systematical research work on the mechanical behaviors of rock bedded slope under rainfall by the research method of the similar simulation test and the numerical simulation analysis. The main research achievements are as follows:1. The characteristic of seepage flow for rock slope is analyzed, and the effect of rainfall infiltration on rock slope is studied. This paper also carries on research on the process of rainfall infiltration. The method to calculate stability coefficient of fractured rock slope is given and being used in analyzing project case.2. According to the similarity theory, combined with project fact of K307work, similarity model test study on the stability of bedded rock slope due to rainfall infiltration have been carried out. The similarity ratio has been constructed and the mix ratio of simulation materials for intensely weathered rock, slightly weathered rock and soft interlayer The material for retaining structure also has been constructed on the basis of similarity ratio. This paper designs model test and decides the layout plan for sensors. The test model has been constructed finally.3. This paper carries on model tests of natural slope, slope retained by anchor frame beam and slope retained by anchor frame beam and anti-slide pile with slope angle of25°and30°under the condition of rainfall. The change rule of liquid water content, pore water pressure and slope displacement in soft interlayer as internal force of retaining structure during rainfall has been studied and comparative analysis of slope mechanical behaviors with different angles has been done. The achievements shows that the biggest displacement appears at the lower part of slope, the increase of slope angle turns against stability of slope, retaining structure plays an important role in slope stability, and different kinds of retaining structure plays different roles. 4. Based on the finite element theory and combined with the established slope model, Midas/GTS has been used to analyze distribution of slope pore water pressure under different rainfall intensity and change rule of internal force for retaining structure. Furthermore, the stability and displacement of slope during rainfall has been studied. This paper also carries research on internal force of retaining structure during rainfall. The results of numerical analysis were compared with real data obtained from laboratory tests, the results show that changing trends obtained with both methods are basically consistent.