水载预压下复合地基沉降及桩土受力特性分析  

Analysis on the Settlement and Characteristics of Pile-soil Stress for Composite Foundation under Water Preloading

作　　者：周大垚 倪芃芃 ZHOU Dayao;NI Pengpeng(Guangdong Communication Planning&Design Institute Group Co.,Ltd.,Guangzhou 510507,China;School of Civil Engineering,Sun Yat-sen University,Guangzhou 510275,China;State Key Laboratory for Tunnel Engineering,Guangzhou 510275,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai 519082,Guangdong,China;Guangdong Key Laboratory of Marine Civil Engineering,Guangzhou 510275,China;Guangdong Research Center for Underground Space Exploitation Technology,Guangzhou 510275,China)

机构地区：[1]广东省交通规划设计研究院集团股份有限公司,广州510507 [2]中山大学土木工程学院,广州510275 [3]隧道工程灾变防控与智能建养全国重点实验室,广州510275 [4]南方海洋科学与工程广东省实验室(珠海),广东珠海519082 [5]广东省海洋土木工程重点实验室,广州510275 [6]广东省地下空间开发工程技术研究中心,广州510275

出　　处：《路基工程》2024年第2期62-70,共9页Subgrade Engineering

基　　金：国家自然科学基金面上项目(52078506);广东省自然科学基金面上项目(2023A1515012159)。

摘　　要：以广东省某高速公路T3标段为研究对象,部分路段采用预制管桩复合地基加固软土地基,采用水袋加载的方法进行等载预压,选取3个典型监测断面埋设传感器,监测分析地基土和桩身的沉降、土压力、桩身轴力的变化规律。结果表明:复合地基中桩体为主要的受荷体,设置褥垫层使其产生刺入变形,可有效调动地基土的承载力;荷载在地基中的传递存在滞后性,提升加载速率可有效改善荷载的传递速率,分级加载有助于达到更好的预压效果;过大的加载速率会导致土压力与桩身轴力出现波动,通过荷载重分配实现桩土共同承担上部荷载。采用水载预压联合预制桩复合地基处理软土路基,可降低30%的施工成本,且可有效提升地基工后的稳定性。Taking T3 section of a highway in Guangdong province as the research object,in some sections,the prefabricated piles composite foundation is used to strengthen the soft soil foundation.which used the water bag loading method for equal load pre-pressure,three typical detection sections are selected to embed sensors to monitor and analyze the foundation soil and pile settlement,soil pressure and pile axial force change rule.The results show that the pile body is the main loaded body in the composite foundation,and the setting of bedding layer can make it produce stabbing deformation to effectively mobilize the bearing capacity of foundation soil.There is a hysteresis in the load transfer in the foundation,and the load transfer rate can be improved by increasing the loading rate,the graded loading can help to achieve a better pre-compression effect.Too large loading rate will lead to the fluctuation of soil pressure and pile axial force,and the pile and soil jointly bear the upper load through load redistribution.By using water-loading preloading combined with prefabricated pile composite foundation to treat soft soil subgrade,it can not only reduce the construction cost by 30 %, but also effectively improve the stability of the foundation after construction.

关 键 词：复合地基 水载预压 现场实测 地基沉降 桩土应力 预制管桩 

分 类 号：TU432[建筑科学—岩土工程]