As one typical clay,the red clay is widely distributed in Yunnan,Guizhou,Sichuan,Guangxi and Guangdong provinces in China.Its engineering properties are complicated.The red clay subgrade treatment is related to the highway engineering construction quality.Gravel pile with excellent permeability,could accelerate the speed of consolidation and settlement of red clay.As a foundation design method to satisfy the bearing capacity,settlement requirements,and enhance the foundation seismic performance,is widely used in the foundation treatment of large area.This paper is based on the case of red clay subgrade treatment in the expansion and reconstruction project of Xiaolong highway,make a comparative analysis of ABAQUS numerical simulation,theoretical analysis and field bearing capacity test,post-construction settlement monitoring,Research the characteristics of composite foundation in Yunnan Xiaopu to Wulong highway engineering in the K2 + 160 ~ K2 +292 section,the main contents include:?By comparing and analyzing the results of subgrade settlement before and after the treatment,the effect of vibro replacement stone column on foundation consolidation settlement of red clay is proposed.?Through the comparison and analysis of the results of experiments and numerical simulation for bearing capacity of the single pile and the composite subgrade,the calculation parameters of the gravel pile design are optimized.?The effects of gravel pile compression modulus,cushion compression modulus and gravel layer thickness on the consolidation settlement of red clay composite subgrade and the stress ratio of pile-soil analyzed by finite element method,provides the basis for the optimization of calculation methods and formulas. |