Analysis Of The Shear Characteristics And Slope Stability Of Landslide Deposits Filling Materials

Loose deposits can be divided into landslide deposits,alluvial deposits,diluvial deposits,and colluvial deposits or the mixture of them according to the cause of formation.Its engineering properties are quite different from homogeneous soil and crushed rock.With the rapid development of highway in China,more and more road constructions will come across the special geological materials.Based on the field investigation in Luonan and Lueyang County,Shaanxi Pronvince,the paper studied the shear characteristics and slope stability of landslide deposits filling materials using the methods of indoor test and numerical simulation.The main achievements of the dissertation are as follows:1)Field investigation was carried out along the road BaLi-Shangzhou District in Luonan County and the highway near Lueyang County.It is concluded that the loose deposits in the two areas are mainly composed of three types: alluvial deposits,landslide deposits and residual deposits,which are widely distributed and extremely uneven.The scales of the particles in the study area range from 0.1m to 1.0 m and the particle size distribution of different regions changes greatly.2)Sieve analysis and compaction test of specimens taken from LingYan temple in LueYang county were performed.The results show that the specimen has a higher rock particle content between 55% and 60%.The optimum water content of the landslide deposits sample decreases and the maximum dry density reaches the maximum when the rock particle content is 65% and then decreases with the increasing rock particle content.3)Large-scale direct shear tests were conducted on the reconstituted landslide deposits samples.The shear strength,cohesive force,internal friction angle,and characteristics of volumetric strain are studied based on the shear stress-horizontal displacement curves with different rock particle content and water content.The sensitivity of cohesive force and internal friction angle to water is also analyzed.4)The Geo-Studio numerical simulation was used to analyze the stability of the landslide deposits near LingYan temple under conditions of moderate rain,heavy rain and rainstorm.The results indicate the safety factor of slope stability decreased rapidly and then slowed down.The order of the descending value of the safety factor is moderate rain>heavy rain>rainstorm.