Research On Triaxial Creep Characteristics Of Lvliang Area Q₃ Loess

With the rapid development of my country’s economy,infrastructure construction has become an important factor to improve the efficiency of economic development.As loess widely distributed in my country,it has become a key field of research for geotechnical workers.Loess is a special kind of soil.Due to its complicated internal structure and special material composition,the mechanical properties of loess are complicated,especially the rheological properties of loess have a great influence on the long-term stability of the project.This article takes the Q₃ loess in Lvliang area as the research object,systematically studies the physical and mechanical properties and rheological characteristics of the Q₃ loess in this area,specifically divided into the following aspects:（1）In this paper,the basic physical and mechanical properties of the Q₃ loess in the Lvliang area were tested.The test results show that there is a significant linear relationship between the density and water content of the Q₃ loess in the study area,from which the dry density of the Q₃ loess is 1.376g/cm³;Q₃ loess has the largest content of powder particles in the particle size composition,accounting for about 70%of the total particles,followed by clay particles,accounting for about 25%of the total particles;Q₃ loess is a medium compressible soil,and its collapsibility grade is mild and moderate.（2）Through the conventional triaxial tests with different water content（5%,10%,15%,20%）and confining pressure（50k Pa,100k Pa,150k Pa,200k Pa）,the test results show that the stress-strain characteristics and water content of the Q₃ loess in Lvliang area It is closely related to the confining pressure,and a functional relationship between the strength index c andφof the loess and different water contents is obtained.（3）Through the triaxial creep test,the creep curve is analyzed:the Q₃ loess sample in the Lvliang area reflects the two typical creep stages of initial creep and constant velocity creep under different test conditions:analyzing the stress-strain isochronous curve,you can The creep failure stress of the soil sample is obtained;the deformation characteristics of the loess are very different with different partial stresses;based on the test data,the comprehensive functional relationship between the creep failure stress of the loess and the water content and confining pressure is obtained.Based on previous research results,the creep mechanism of loess was briefly analyzed through experiments.（4）Through creep test results,the creep constitutive model of Q₃ loess in Lvliang area was established,and three empirical models,Singh-Mitchell creep model,Mesri creep model and author’s own creep model,were analyzed.The variable empirical model is more suitable for the creep characteristics of the Q₃ loess in the study area;the generalized Kelvin model suitable for the Q₃ loess in the study area is established.