既有建筑桩基础开挖过程中承载特性数值分析  

Numerical Analysis on the Bearing Behavior of the Existing Building's Pile Caused by Excavation around Piles

作　　者：贾强[1] 张鑫[1] 张琳 

机构地区：[1]山东建筑大学土木工程学院,济南250100 [2]山东省能源建筑设计院,济南250002

出　　处：《地下空间与工程学报》2016年第1期114-118,共5页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51278286);教育部长江学者和创新团队项目(IRT13075)

摘　　要：既有建筑物增设地下空间时,需要运用桩基础支撑上部建筑物,才可开挖建筑物下面的土方。随着桩周土减少和桩基础的暴露,桩的承载特性会出现变化。运用ANSYS有限元程序分析了桩周土开挖前、开挖10m和开挖20m等工况下,桩基础承载特性的变化规律。从分析的结果可以看出,开挖前后桩基础沉降表现出中间桩沉降大、周边桩沉降小的规律;随着开挖深度增大,桩基沉降量明显增大。上段桩周土开挖后,不仅造成未开挖部分桩身侧阻力和桩土间的滑移量增大,而靠近开挖面处增加更明显。当开挖至桩承载力接近极限状态时,桩底的侧阻力和滑移值逐渐接近开挖面附近的数值。The underpinning pile can be used to support the existing building for construction of basement. The soil excavation around the pile can decrease the bearing capacity of piles. Finite element analysis based on Ansys code are established to study the bearing behavior of piles in three steps： before soil excavation,10 m depth soil excavation,20 m depth soil excavation. Some conclusions are drawn as follows： the settlement values of column-heels in middle part were larger than those in the area around; in the soil digging phase, the settlement values of pile increase. The soil excavation around the pile caused the increasing of piles side resistance and the slip value between the pile and soil,and more obvious near the excavation face. While the bearing capacity of piles approaching the limit state,the piles side resistance and the slip value were close to values of those near the excavation face.

关 键 词：桩周土开挖 桩侧阻力 数值分析 沉降 

分 类 号：TU473.1[建筑科学—结构工程]