Study On The Attenuation Law And Fine Microstructure Of Compacted Red Clay In Highway Engineering

The red clay is different from the general cohesive soil,mainly in the high water content,high plasticity,high void ratio,even high strength and other physical properties and mechanical parameters of the law.Based on the regularity of dry and wet mechanical properties of red clay under cyclic attenuation of National Natural Science Fund Project "(NO.51368010),based on previous research results on the red clay,red clay subgrade in Guizhou,Guizhou University in the two phase of the project of red clay as the research object,in the soil and soil mechanics theory,the testing technology of geotechnical engineering methods,through field investigation,laboratory experiment,theoretical analysis and Research on the attenuation of compacted red clay under cyclic drying and wetting law.The research results are as follows:(1)The stress-strain curve of red clay began to be steep,and when the strain reached a certain value,the curve became smooth,and there was no peak.Damage in the form of bulging damage,no obvious failure surface;(2)The shear strength index of soil samples(cohesion C,internal friction angle)decreases with the increase of moisture content,and increases with the increase of compaction degree,and decreases with the increase of the number of cycles;(3)With the increase of the number of cycles n,the cohesion C decreases monotonously,and the internal friction angle is in the range of 5 degrees;(4)Under the same conditions,the shear strength index is generally higher than that of high temperature test.With the increase of the number of cycles,the first time after drying,the shear strength index is lower than the first dry wet test;(5)The calculation parameters of slope stability under dry and wet cycles are as follows: the value of cohesion stability is from 55% to 60% of the initial state,and the stable value of the internal friction angle is about 50% of the value of the circulation.The research results will provide better technical support for the design of slope stability in red clay area,to prolong the service life of highway maintenance management,reduce costs,and has great economic benefit and social benefit,and provide technical reference for other industries.