【作者】 候跃； 刘涛； 黄永亮；

【Author】 HOU Yue;LIU Tao;HUANG Yongliang;Shandong Province Key Laboratory of Marine Environment Geology Engineering,Ocean University of China;

【机构】 山东省海洋环境地质工程重点实验室(中国海洋大学)；

【摘要】 膨胀土的胀缩特性、裂隙性、超固结性常对膨胀土地层中的工程建设造成不良影响,以热-力耦合数值模拟为基础对膨胀土深基坑开挖过程中的受力变形特性进行研究。首先由室内试验测定原状膨胀土的膨胀力,然后以FLAC^3D热-力耦合模块模拟一环刀土样推导目标膨胀力下的膨胀系数,最后以扬州某膨胀土深基坑为例,计算上述膨胀系数下深基坑在开挖过程中的受力变形特性,并与基坑实测数据进行了对比。结果表明:（1）围护结构侧向变形轮廓线为"鱼腹型",最大侧向变形位置发生在开挖面以上一定范围内,最大侧向变形值大致为（0.15%⁰.30%）H;（2）立柱隆沉曲线平缓,数值大致处于（-0.04%⁰.14%）H;（3）墙后地表沉降槽呈"√"型,影响范围达到了2.5H_e以外,最大地表沉降值为δ_vm=（0.05%⁰.15%）H,最大地表沉降与最大围护结构侧向变形的关系约为δ_vm=（0.33⁰.56）δ_hm;（4）土压力值均处于视土压力包络线范围以内,大致为1.07γH_e。更多还原

【Abstract】 Construction in expansion soil layer is often adversely affected by swell-shrink,fissure,over-consolidation characteristics of expansion soil,the mechanics and deformation characteristics of expansion soil deep foundation pit during excavation is studied based on coupled thermo numerical simulation.At first,the expansion force of undisturbed expansion soil is measured by laboratory test,and then a ring knife soil sample is simulated using coupled thermo module of FLAC,to derive expansion coefficient under target expansion force,finally mechanics and deformation characteristics of deep foundation pit in excavation process under Above-mentioned expansion coefficient is calculated,taking a Yangzhou expansion soil foundation pit as an example,and comparing with the measured data of the foundation pit.The main research conclusions are as follows:（1） Contour line of retaining structure lateral deformation is shaped like a fish belly,the maximum lateral deformation occurs in a certain range above the excavation face,the maximum lateral deformation is approximately（0.15%⁰.30%）H;（2）The curve of vertical column displacement is gentle,the value is approximately（- 0.04% 0.14%） H;（3） The surface settlement trough behind the retaining wall is ’√ ’ type,the influence range is beyond 2.5H_e,the maximum surface settlement is δ_vm =（0.05%⁰.15%）H,the relationship between maximum surface settlement and maximum lateral deformation of retaining structure is approximately δ_vm =（0.33 ⁰.56）δ_hm;（4）The earth pressure values are within the range of the earth pressure envelope by measurement,the value is substantially 1.07γH_e.更多还原