深厚软土地基群桩沉降计算深度现场试验研究  

Field Test for Determining Compression Layer Thickness under Pile Group in Deep Soft Soil Foundation

作　　者：陈福江[1] 马建林[1] 朱林[1] 乐大维[1] 

机构地区：[1]西南交通大学土木工程学院,成都610031

出　　处：《地下空间与工程学报》2015年第5期1144-1151,共8页Chinese Journal of Underground Space and Engineering

基　　金：铁道部京沪高速铁路科技重大专项(2008G031-B);国家自然科学基金(51009130)

摘　　要：选取京沪高速铁路3处桥梁群桩深厚软土地基为试验点,采用单点沉降计和液位沉降计联合观测,并通过远程自动监测系统对监测数据进行实时自动采集和传输,对深厚软土地基群桩的沉降计算深度进行现场测试。现场实测表明,对于粉砂类持力层、粉质黏土持力层和黏土类持力层,计算沉降深度分别约为桩基外缘轮廓短边长度的1.2倍、1.5倍和2.1倍。测试结果和规范法计算结果对比分析表明,在10%应力比的情况下,应力比法计算得出的计算沉降深度与实测值较接近,其平均值比实测值高约15%;在20%应力比的情况下,应力比法计算得出的计算沉降深度较实测值偏小,平均值比实测值低27%;由变形比法计算得到的计算沉降深度通常偏大,平均值比实测值大77%。The on-site tests on calculated settlement depth in deep soft soil foundation were conducted under three bridge pile groups of Beijing-Shanghai high speed railway by liquid level settlement meter and single point settlement meter,and the monitoring data were collected and sent automatically in real time by remote auto monitoring system. The test results show that the calculated settlement depths in sandy bearing strata,silty clay bearing strata,and clay bearing strata are about 1. 2 times,1. 5 times,and 2. 1 times the outer short side length of pile group,respectively. The comparison between test results and calculated results by code methods shows that the calculated results under 10% stress ratio condition are the closest to test results,with average calculated results slightly larger than test results by 15%; the calculated results under 20% stress ratio condition are less than test results,averagely by27%; the calculated results under settlement ratio condition are generally larger than test results and in average by 77%.

关 键 词：深厚软土地基 群桩 沉降计算深度 应力比法 变形比法 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]