不同含水率条件下EPS颗粒轻量土蠕变特性试验研究  

EXPERIMENTAL ON CREEP PROPERTIES OF EPS BEADS LIGHT WEIGHT SOIL UNDER DIFFERENT WATER CONTENTS

作　　者：刘德方[1] 侯天顺[1] Sibel Pamukcu 

机构地区：[1]西北农林科技大学水利与建筑工程学院,杨凌712100 [2]里海大学土木与环境工程系,美国宾夕法尼亚州伯利恒市18015

出　　处：《工程地质学报》2017年第1期102-109,共8页Journal of Engineering Geology

基　　金：国家自然科学基金项目(51509211);西北农林科技大学博士点基金项目(2011BSJJ084);西北农林科技大学大学生创新训练项目(201410712093)资助;陕西省自然科学基金项目(2012JQ7013);中央高校基本科研业务费专项资金项目(QN2012025);陕西省专项配套经费项目(Z109021108);陕西省社会发展科技攻关项目(2015SF260);国家留学基金项目(201406305047)

摘　　要：为了得到轻量土路基中央部位在长期荷载作用下的蠕变规律,通过单向固结蠕变试验,分析了不同含水率EPS颗粒轻量土、素土在不同轴向压力下的蠕变特性。研究表明:固定其他因素,轴向压力越大,含水率越高,土样蠕变变形越大。轻量土加载1d基本上可以达到总变形的93%~98%,蠕变变形具有明显的衰减特征。轻量土是一种结构性土体,与素土蠕变机理完全不同。当轴向压力小于压缩屈服应力时,轻量土蠕变变形主要是孔隙闭合、水分的排出、固体颗粒移动的结果;当压力大于压缩屈服应力时,轻量土土样原有结构被破坏,EPS颗粒自身会被压缩。基于土体衰减蠕变特征,本文依据双曲线模型建立了轻量土经验蠕变模型,基本上可以反映路基中央部位轻量土的蠕变规律,经验模型适用于轻量土条件为轴向压力小于土体压缩屈服应力。试验与理论计算分析表明,轻量土固结特性优于素土,路基沉降在施工过程中就可以达到稳定,运营期间的工后沉降基本可以忽略。In order to gain the creep laws of light weight soil which is in the central part of the subgrade under long-term loading,the creep properties of light weight soil and remolded soil with different water contents and axial compression force were analyzed by one-dimensional compression tests. The results show that when other factors are the same,the higher the axial compression force and water content are,the greater the creep deformation of soil samples is.The deformation of light weight soil under loading for one day can basically reach 93%~ 98%of the whole deformation,and the attenuating creep is obvious. Light weight soil is a kind of structural soil,and it has different creep mechanism with remolded soil. When the axial compression force is no more than the compressed yield stress,the creep deformation is mainly from holes closure,drainage water,solid particles＇ movement. When the axial compression force is more than the compressed yield stress,the original structure of the light weight soil will be destroyed and EPS beads will be compressed. Based on the attenuation creep characteristics of light weight soil,an empirical creep model is established base on the hyperbolic model. When the axial compression force is less than the compressed yield stress,it can basically reflect the creep laws of light weight soil which is in the central part of the subgrade. By the experiments and theoretical calculation analysis, it is found that the consolidation characteristic of light weight soil is better than that of remolded soil. So the subgrade settlement can reach a stable value after the construction,and the post-construction settlement can almost be neglected during the operation.

关 键 词：轻量土 含水率 蠕变特性 蠕变试验 蠕变模型 

分 类 号：TU411.3[建筑科学—岩土工程] P642.3[建筑科学—土工工程]