市政技术2024，Vol.42Issue(12)：75-83,9.DOI:10.19922/j.1009-7767.2024.12.075
不同重塑含水率下黏土路基填料的无侧限抗压强度
Unconfined Compression Strength of Clay Subgrade Fillings with Different Reshaped Water Contents
摘要
Abstract
As the commonly used roadbed filling materials in road engineering construction,clay's strength charac-teristics are crucial for the safe and stable service of roads.However,during the on-site filling process of the roadbed,precise control of the reshaped moisture content is difficult,resulting in changes in the microstructure and strength characteristics of the filling material.The study is to explore the variation of unconfined compression strength(UCS)of clay subgrade fillers with different remolded moisture contents.UCS tests were conducted on sev-en types of clay subgrade fillers with 7 different reshaped moisture contents(14％,16％,18％,20％,25％,28％,30％).And the apparent morphology of typical samples was observed using scanning electron microscopy(SEM).The results show that:l)With different remolding moisture contents,the stress-strain relationship of clay subgrade filling materials exhibit strain softening characteristics,which is a typical brittle failure form,and becomes more pronounced with the increase of remolding moisture content and loading strain rate.2)UCS of clay subgrade filling shows a"bell shaped"variation pattern,which show firstly increasing and then decreasing with the increase of re-shaped moisture content.The characteristic reshaped moisture content w-cha=19％can be defined at the peak point of the curve,and the w-cha value is lower than the optimal moisture content(wopt=28％).This variation pattern is related to the changes in clay particles and matrix suction.3)When the reshaped moisture content changes around w-cha=19％(±1％),UCS remains basically unchanged;When the reshaped moisture content varies within a wide range(beyond±1％),the UCS change rate increases with the decrease of reshaped moisture content on the w-cha dry side.On the w-cha wet side,UCS change rate increases with the increase of reshaped moisture content.The research results provide a scientific basis for understanding the engineering behavior of clay subgrade fillers under different reshaped moisture content conditions.关键词
非饱和土/黏土/路基填料/重塑含水率/无侧限抗压强度/微观结构Key words
unsaturated soils/clay/subgrade fillings/reshaped water content/unconfined compression strength/microstructure分类
建筑与水利引用本文复制引用
汪晶,刘锦辉,亓帅,马伟..不同重塑含水率下黏土路基填料的无侧限抗压强度[J].市政技术,2024,42(12):75-83,9.基金项目
国家自然科学基金青年项目(52108295) （52108295）
北京建筑大学培育项目-青椒计划(X24023) （X24023）
北京建筑大学'建大英才"项目(JDYC20220811) （JDYC20220811）
