考虑降水作用下滨海地层深基坑变形特性研究

以厦门地铁共建段基坑工程为背景,采用数值模拟和现场实测方法对比研究滨海吹填砂和淤泥特殊土地层降水前后基坑挡墙侧移、地表沉降、坑底回弹及支撑轴力的变化规律。研究结果表明,考虑降水作用下基坑变形是土体固结和坑内卸载作用共同导致的。虽然基坑设计深度是影响变形的主要因素,但是降水作用对滨海地层造成的影响仍不能忽略;同时对于钢支撑的轴力损失采取相应的施工处置措施。研究成果可为滨海地层深基坑施工控制提供参考。

Taking the foundation pit project of Xiamen Metro joint section as the background,the numerical simulation and field measurement methods are used to compare the change rules of the foundation pit retaining wall side displacement,surface settlement,pit bottom rebound and supporting axial force in the coastal sand blowing and silt special land layer.The results show that the deformation is the result of soil consolidation and unloading in the pit.Although the design depth is the main factor affecting the deformation,the influence of precipitation on the coastal strata cannot be ignored.Meanwhile,corresponding construction measures are taken for the axial force loss of steel support.The research results can provide a reference for the construction control of deep foundation pit in coastal strata.