“中心岛法”斜支撑基坑开挖坡比探讨  

Investigate on Gradient Slope Applying the Construction of Central Island With Inclined Brace

作　　者：徐德馨[1] 唐传政[2] 彭汉发[1] 张杰青[1] 施木俊[1] 

机构地区：[1]武汉市勘测设计研究院,湖北武汉430022 [2]武汉市建设工程设计审查办公室,湖北武汉430015

出　　处：《城市勘测》2008年第5期157-160,共4页Urban Geotechnical Investigation & Surveying

基　　金：武汉市建委科研课题;编号200722

摘　　要：采用三维有限元分析方法，对武汉某基坑“中心岛法”开挖施工过程进行了模拟，分析了开挖过程中支护结构水平位移和基坑周边地表沉降的变化过程，为基坑初步设计和优化设计提供了参考。在同一地层和支护布设情况下，采用不同坡比开挖对基坑支护结构水平位移及周边地表沉降的影响进行了研究，研究结果表明：随着斜坡开挖坡度的增加，斜坡开挖前后支护结构水平位移和基坑周边沉降不断增加，且增大的幅度越来越大；针对不同的基坑场地和周边环境情况，选取合理的斜坡坡比，对控制基坑开挖对周边环境的影响以及缩短基坑工期等有很好的作用，从基坑安全性和工期两方面综合考虑得出武汉一级阶地两层地下室及以下基坑较合适的开挖坡比为1：1．0～1：1．5。Through 3D finite element analysis the construction course of some foundation excavation applying construction of central island in Wuhan is simulated, analyzing the changing course of horizontal displacement of supporting system and settlement curves of surrounding surface by excavation, in order to providing reference for preparatory and optimized design of foundation excavation. In the same circumstances of soil stratum and supporting system arrangement, influence on horizontal displacement of supporting system and settlement curves of surrounding surface of different gradient slope is analyzed, study results show that：with the gradient of slope increases, horizontal displacement of supporting system and settlement of surrounding surface by fore - and - aft slope excavation increase, also the rate of increase increases;considering different pit field and surrounding enviromnent, selecting a reasonable slope gradient has a very good effect on controlling the impact on surrounding environment and reducing the excavation period. Comprehensive consideration of time limit and safety of excavation, two - story and below basement excavations of which the appropriate slope gradient is 1 ： 1.0 - 1 ： 1.5 in the first terrace in Wuhan.

关 键 词：基坑开挖 “中心岛法” 斜支撑 三维有限元分析 修正剑桥模型 

分 类 号：TU470[建筑科学—结构工程]