北京某深基坑开挖过程的阳角效应分析  

Analysis on External Angle Effect in Excavation of a Deep Foundation Pit in Beijing

作　　者：董淑海 张雪东 沈宇鹏[3] 左瑞芳[3] 

机构地区：[1]中交第三航务工程勘察设计院有限公司,上海200032 [2]中交铁道设计研究总院有限公司,北京100088 [3]北京交通大学土木建筑工程学院,北京100044

出　　处：《路基工程》2017年第4期175-179,195,共6页Subgrade Engineering

摘　　要：以北京市某深基坑支护工程为例,运用ABAQUS有限元软件,建立了桩锚支护体系分析模型,分析了不同施工工况下基坑开挖过程中的阳角效应,并与实际工程实测结果进行了对比分析。结果表明:(1)阳角凸出部位的桩体顶部最大变形量大于其他部位,该部位的锚杆力在整个开挖过程中也比较大;(2)阳角角度制约着基坑的开挖过程,同一深度处阳角角度越小,基坑开挖难度越大;(3)基坑阳角凸出长度对桩顶变形及桩体弯矩影响显著,但随着凸出长度的增大,影响效果渐弱;(4)桩体横向位移和弯矩均随基坑开挖深度的加大而逐渐增大;(5)地基最大隆起量受阳角凸出长度及基坑开挖深度影响较大,且凸出长度和开挖深度越长,影响效果越明显。A deep foundation pit supporting project in Beijing was taken as an example in this paper. By using the ABAQUS finite element software, a pile anchor supporting system analysis model is established and the external angle effect in excavation of a foundation pit under different construction conditions is analyzed and compared with the actual engineering measurement results. The results showed： ① The maximum deformation of foundation pile top at the protruding position is larger than that of other parts, and the anchor force of this position is also larger in the whole excavation process ; ② The size of the external angle restricts the excavation process of the foundation pit. The smaller the size of the external angle is, the more difficult the excavation is. ③ The external angle＇s protruding length of the pit has a significant effect on the deformation of the pile top and the bending moment of the pile, but the effect is weaken with the increase of the protruding length. ④ Both the lateral displacement and bending moment of the pile are increased with the increase of excavation depth gradually. ⑤ The maximum bulge of the foundation is greatly affected by the protruding length of the external angle and the excavation depth of the foundation pit, moreover, the longer the protruding length and the excavation depth, the more obvious the effect is.

关 键 词：深基坑 阳角效应 桩锚支护体系 空间效应 

分 类 号：TU712.4[建筑科学—建筑技术科学]