砂井—管桩处理区结合部变形特征的研究  

Research on Deformation Characteristics of Soil in the Joint Zone of the Treatment Soft Foundation by Sand Well and PHC pipe

作　　者：孙克强 曾繁斌 李国维[2] 刘日新 SUN Ke-qiang;ZENG Fan-bin;LI Guo-wei;LIURi-xin(Guangdong Road and Bridge Construction Development Co.Ltd.,Guangzhou 510510,China;Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210024,China;Guangdong Communications Planning&Design Institute Group Co.Ltd.,Guangzhou 510510,China)

机构地区：[1]广东省路桥建设发展有限公司,广州市510510 [2]河海大学岩土力学与堤坝工程教育部重点实验室,南京市210098 [3]广东省交通规划设计研究院集团股份有限公司,广州市510510

出　　处：《公路》2024年第11期68-75,共8页Highway

基　　金：国家自然科学基金项目,项目编号51908235、42177126。

摘　　要：工程中由于各种因素限制,在同一地质条件下常常需要采用两种或以上的地基处理方式,然而处理区结合部应力复杂,需要研究揭示其变形特点。以某沿海高速公路项目为依托,首先开展现场试验研究,分析砂井与PHC管桩处理区结合部位土体的沉降变形规律,揭示结合部差异沉降的影响范围,结果显示在处理区分界线15 m范围内,砂井地基差异沉降明显;其次,利用有限元模拟现场试验,并在已经验证的数值模拟中分析桩体挠曲变形,数值模拟表明桩体产生的挠曲变形方向为背离砂井区,最大位移处在软土层中,且其位置越靠近砂井区,则变形越大。研究结果表明,当采用袋装砂井与PHC管桩处理软土地基时,交界面处桩体挠曲变形需要特别关注,砂井长度减小使得软土快速排水固结区缩小,整体沉降减少;管桩区整体沉降不受砂井长度变化的影响;边桩最大挠曲变形对于堆载厚度比对于砂井长度更加敏感。Due to various factors in projects,it is inevitable to adopt two or more methods to treat the soft foundation even under the same geological conditions.However,the stress of the joint area of the treated foundation is complicated,and it is necessary to study and reveal its deformation characteristics.Relying on a costal expressway project,field tests are carried out first to analyze the soil settlement and deformation features in the junctional area treated by sand well and PHC pile,and reveal the range that significant differential settlement affects.The results show that within 15 m from the boundary of the two treated areas,the differential settlement of the sand well foundation is significant.Secondly,the field test is simulated by finite element method,and the lateral displacement of the pile is analyzed from the verified numerical simulation.Numerical analysis shows that the direction of the lateral displacement of the pile is outward the sand well,the maximum displacement is located in the soft soil layer,and closer to the sand well area,greater the deformation is.When sand wells and PHC piles are used to treat soft soil foundations,the lateral displacement of the side piles requires special attention.The parameter analysis shows that the rapid drainage and consolidation area of soft soil decreases and the overall settlement decreases with the decrease of sand well length.The overall settlement of PHC pile area is not affected by the change of sand well length.The maximum deflection deformation of side pile is more sensitive to the load thickness than the sand well length.

关 键 词：软土地基 袋装砂井 PHC管桩 地基差异沉降 桩体挠曲变形 

分 类 号：U416.5[交通运输工程—道路与铁道工程] TU472.32[建筑科学—结构工程]