Research On Environmental Geologic Hazards Of Railway Slope In Typical Loess Area

With the further implementation of Western Development in China, there has grown up an urgent need of economic construction for building railway tracks under different geological conditions. In loess areas, problems resulting from slope environment and geological disasters will seriously influence the normal management and operation of the roads. Therefore, on fully discussing the major categories and influencing factors of geological failures, the present study focuses on landslides and collapse which are common in loess districts. Taking the loess slope from Watang to Hongdong sections of the railroad in the centric-south area of Shanxi as its research subject, we have systematically analyzed the main forces that affect the geologic hazards in slope environment on the basis of exploring the topography and geomorphology, geological structures, hydrogeological conditions of the target areas and construction activities of human. It comes a conclusion that the environmental geology is affected most by the types of slope and projection of excavation. What’s more, a conceptual model of factors affecting geological disasters which occur from Watang to Hongdong sections of the railroad in the centric-south area of Shanxi is set up in the research.Through the FLAC3D (Fast Lagrangian Analysis of Continua in3Dimensions) software, we analyze the displacement and the3-D numerical simulation of stress of the loess slope from Watang to Hongdong of the railroad in the centric-south area of Shanxi. By comparing the diagrams of displacement and stress after the first, third, fifth and seventh step of excavations, we find that with excavating, the displacement of the slope is increasing, which severely affects the stability of the slope. Meanwhile, stress concentration occurs at the bottom of slope, rendering the possibility of geologic hazards. Thus both excavating areas and the toe of slope need reinforcing so as to reduce the concentration of stress. To sum up, this research will provide necessary theoretical framework for railway construction from Watang to Hongdong sections in Centric-southern Shanxi and is hoped to play a drawing lesson to the similar railroad building in the future.