考虑变形时间效应的地基压缩层厚度试验验证  

Experimental Verification of Foundation Compression Layer Thickness Considering Deformation Time-effect

作　　者：朱江江[1,2] 罗强 熊勇[3] 陈侃 ZHU Jiangjiang;LUO Qiang;XIONG Yong;CHEN Kan(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031 China;China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430063 China;Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources,Yangtze River Scientific Research Institute,Wuhan 430010 China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]中铁第四勘察设计院集团有限公司,武汉430063 [3]长江水利委员会长江科学院水利部岩土力学与工程重点实验室,武汉430010

出　　处：《铁道建筑》2020年第10期73-77,88,共6页Railway Engineering

基　　金：国家重点基础研究发展计划(2013CB036204)。

摘　　要：对高速铁路长期服役性能有影响的路基工后沉降主要来源于地基中具有显著时间效应变形的土层。通过离心模型试验,研究了重塑中低压缩性粉质黏土地基在路堤荷载作用下的变形时间效应;分析了地基在浅层同一加固深度、下部土层压实度改变的情况下,地基塑性变形时间效应随路堤高度的变化规律。结果表明:低矮路堤荷载作用下地基变形具有显著时间效应的土体主要分布在浅层,即使下部土层压实度改变仍不会对地基变形状态产生影响;路堤高度增加会引起地基变形具有显著时间效应的土层加厚,并超过预设的浅层加固厚度,导致下部土层的变形状态由微弱转变为显著;验证了采用时间效应法确定地基压缩层厚度的合理性。The post construction settlement of high speed railway subgrade,which affects the long-term service performance of high speed railway,mainly comes from the soil layer with significant time-effect deformation.Through the centrifugal model test,the time-effect of deformation of the remodeled low and medium compressibility silty clay foundation under the embankment load was studied.The time-effect of the plastic deformation of the foundation with the height of the embankment was analyzed under the condition of the same reinforcement depth in the shallow layer and the change of the compaction degree of the lower soil.The results show that the soil with a significant time-effect of foundation deformation under low embankment load is mainly distributed in the shallow layer,even if the lower soil compaction changes,the deformation state of the foundation will not be affected.The increase in the height of the embankment will cause the foundation to deform.The soil layer with significant time-effect will thicken and exceed the preset shallow reinforcement thickness,causing the deformation of the lower soil layer to change from weak to significant.The rationality of using the time-effect method to determine the thickness of the foundation compression layer is verified.

关 键 词：高速铁路 压缩层厚度 模型试验 中低压缩性土 地基变形 时间效应 

分 类 号：TU470[建筑科学—结构工程]