Study On Creep Properties And Engineering Application Of Soil-rock Mixture In Qinba Mountains

Qinba mountainous is an area with extremely complicated geological conditions.The mountains and valleys in the area are interlaced with each other,making it a natural breeding ground for geological disasters.It has also been a frequent occurrence area of geological disasters for many years,among which the type of geological hazards is shallow soil-rock mixture landslides.This paper uses a combination of experiment and theory,briefly analyzes the development and evolution of shallow landslides in the Qinba Mountains,and summarizes the creep deformation characteristics of landslides.Based on the creep test of soil-rock mixture under different influencing factors,the creep characteristics under different conditions are analyzed.The numerical simulation method was applied to the analysis of engineering examples.The main research contents and achievements of this article are as follows:1 According to various characteristics,shallow surface landslides in the Qinba Mountains are divided into four stages: the surface unloading stage,the accelerated weathering stage,the weathering accumulation stage,and the shallow landslide occurrence stage.Creep deformation runs through the landslide formation.The whole process of development,development,and on this basis,the type of creep of the slope is divided.2 Taking soil-rock mixture landslides as the research object,the landslide accumulations were subjected to particle analysis,moisture content,and other basic physical property tests,and the soil-rock mixture tests were optimized to match the indoor creep tests under different conditions.Focusing on the creep shear tests of soil-rock mixtures under different influencing factors such as different water content,different particle size groups,and different rock content,the results show that the water content has a greater influence on the creep of soil-rock mixture,and the higher the moisture content is.The creep increment change is more obvious;the creep deformation characteristics of different particle size groups and different rock content are different,and the creep deformation of the 5-10 mm particle size group and 50% of the rock content is the lowest.3 Based on the line viscoelastic H-K model,the viscoplastic element was added to establish the six-element viscoelastic-plastic constitutive model,which was used to describe the plasticity characteristics of the soil-rock mixture in the accelerated creep stage.The correlation between the model and experimental data was good.4 The creep slip mechanism of typical shallow soil-rock mixture landslide was revealed.The finite element software ABAQUS was used to numerically simulate the creep deformation of the landslide.The results showed that the area where the plastic deformation of the landslide was the first to generate plastic deformation was located.At the top of the slope,along with the increase of time,the plastic zone gradually expands along the contact surface of the soil and rock toward the slope foot,which is in line with the actual landslide deformation.