摘要
为探究斜坡基底软土–桩网复合地基的变形特性,以沿海铁路线某深厚软土地基断面为原型,开展比尺为1∶100室内离心模型试验。通过对试验数据的整理分析,结果表明:(1)路堤顶部两侧的竖向和横向位移、两侧沉降差在运营期都有明显增长,但竖向和横向位移主要产生于路堤施工阶段,而沉降差基本产生于运营期内;(2)加筋垫层对其下方的地基表层横向位移有明显约束。地基右侧土体的竖向和横向位移关于路堤中心不对称,表现为右侧大于左侧,地基表面呈现出明显偏向斜坡外侧的非对称"沉降盆";(3)斜坡桩和悬浮桩的桩顶竖向和横向位移明显大于平台桩,平台桩潜在破坏模式为弯拉或弯剪破坏,斜坡桩为倾斜破坏,悬浮桩为倾斜+横移破坏;(4)桩发生明显上刺和下刺现象,且淤泥质黏土表现出流体特性发生绕桩横向流动。
Centrifuge test modeling a typical project of coastal railway line was conducted in order to study the deformation characteristics of pile-geogrid composite foundation in soft soil underneath the slope. The vertical and horizontal movements and the differential settlement of the embankment surface keep increasing during the operation period. The majority amount of the vertical and horizontal movements of the embankment surface was developed during the construction period, while the majority amount of the differential settlement was developed during the operation period. The lateral movement of the soft ground surface is constrained by the geogrid- reinforcement. The horizontal and vertical deformation in soft ground at the side of slope base is larger than the other side, thus an asymmetric settlement basin appears. The vertical and horizontal movements at the head of platform piles are less than that of slop piles and floating piles. The platform piles are under bending and tension or bending and shear deformation, the piles in slope experience the inclination deformation, and the floating piles experience the inclination deformation and lateral movement. The piles pierce upwards into the geogrid reinforcement and downwards into the underlying stratum, and the muddy clay between the slope piles flows around the piles laterally like fluid.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2018年第1期209-219,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
四川省科技计划项目(2015SZ0068)
中国铁路总公司科技研究开发计划课题(2015G006–D)
交通运输部建设科技项目(2013318800020)~~
关键词
桩基工程
斜坡基底
软土
离心模型试验
桩–网复合地基
变形特性
pile foundations
slope base
soft soil
centrifuge model test
pile-geogrid composite foundation
deformation characteristics
