拓宽方式对软土路基工程特性影响的离心模型试验  

Centrifugal test on influence of widening styles on the engineering characteristics of soft soil

作　　者：叶观宝[1] 葛敬文 许言[2,3] 张振 饶烽瑞[4] 戚得健 YE Guanbao;GE Jingwen;XU Yan;ZHANG Zhen;RAO Fengrui;QI Dejian(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Shanghai Institute of Geological Survey,Shanghai 200072,China;Key Laboratory of Land Subsidence Monitoring and Prevention,Ministry of Natural Resources,Shanghai 200072,China;Shanghai Construction No.2(Group)Co.Ltd.,Shanghai 200090,China;CIFI Holdings(Group)Co.Ltd.,Shanghai 201799,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]上海市地质调查研究院,上海200072 [3]自然资源部地面沉降监测与防治重点实验室,上海200072 [4]上海建工二建集团,上海200090 [5]旭辉集团股份有限公司,上海201799

出　　处：《水文地质工程地质》2022年第3期112-117,共6页Hydrogeology & Engineering Geology

基　　金：国家自然科学基金项目(41772281,41972272),中央高校基本科研业务费专项资金(22120190220)。

摘　　要：如何保持新旧路基间的变形协调是拓宽工程中普遍关注的问题,目前尚缺乏对于拓宽方式对软土路基工程特性影响的直接对比分析。本文开展离心模型试验,采用普通填料或气泡轻质土进行放坡或挡墙拓宽,分析了新旧路基变形、地基土中孔压和土压力在路基拓宽后的变化规律。试验结果表明,气泡轻质土显著减小拓宽过程中产生的孔隙水压力增量和附加应力增量。相较于边坡拓宽,挡墙拓宽方式对地基影响更小。轻质土路堤采用挡墙拓宽方式引起的挡墙倾角和墙背土压力均较小。采用Boussinesq公式计算得到的拓宽路堤引起的地基中附加应力分布与实测值基本吻合,且偏于保守。本文的研究成果对指导路基拓宽工程具有借鉴意义。Compatibility of deformation between the existing embankment and widened portion is a common problem in widening projects.There is still a lack of direct comparative analysis of the influence of widening methods on the engineering characteristics of soft soil subgrade.In this study centrifugal model tests are conducted to investigate the widening styles of slope and retaining wall using ordinary or lightweight materials.The embankment deformations,pore pressures and earth pressures in soil are monitored during flight.The results show that using the foamed light-weight soil can significantly reduce the pore water pressure and additional stress increments induced by the construction of the widened portion.As compared with the slope widening,the retaining wall widening had less impact on the foundation.The inclination of the retaining wall and the earth pressure on the back caused by the foamed light-weight soil embankment are low.It is indicated that the additional stress distribution in soil because of the widening portion calculated with the Boussinesq's equation is conservatively in good agreement with the measurements.The research results are meaningful for guiding widening projects.

关 键 词：泡沫轻质土 路堤拓宽 离心模型试验 软土 差异沉降 

分 类 号：TU432[建筑科学—岩土工程]