气压沉箱竖井施工对周边土体环境影响的数值模拟研究  

Numerical simulation of influence on surrounding strata due to shaft construction with pneumatic caissons

作　　者：王海林[1,2] 彭芳乐[1,2] 郭建刚[1,2] 徐正良 刘晨 

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092 [3]上海市城市建设设计研究院,上海200125

出　　处：《岩土工程学报》2008年第S1期62-67,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家科技支撑计划资助项目(2006BAJ27B02-02)

摘　　要：针对气压沉箱特殊的施工工艺及流程,从现场监测和数值模拟两方面对上海某气压沉箱竖井施工对周边土体环境的影响进行了研究。基于监测结果,给出了气压沉箱周边土体地面沉降和水平位移的分布形式及影响范围。根据气压沉箱分节下沉特点,对其下沉过程进行了力学分析,在仅考虑沉箱竖向受力平衡的前提下提出了用于分析施工全过程对周边地层变形的力学模型,并介绍了其在有限元软件中的实现。土体采用Hardening-Soil弹塑性模型(HS模型),可以模拟初次加载和卸载-再加载之间的刚度差别。通过计算结果和实测值的比较,证实了该力学模型及所采用土体参数的合理性、有效性。According to the particular construction technology of pneumatic caissons,in view of the filed monitoring and numerical simulation,the influence on the surrounding strata of one shaft construction employing pneumatic caissons in Shanghai was studied.Based on the measured data,the properties of surface settlement and horizontal movements surrounding the caisson were analyzed.Considering the construction plan,the mechanical analysis for the whole sinking process was conducted,and one mechanical model for analyzing the ground deformation was developed based on the equilibrium of vertical forces acting on the caissons.The implementation of the model in FEM codes was introduced.In order to simulate the difference of soil in stiffness for primary loading and un-/reloading,the hardening-soil(HS) elastoplastic model was employed. A comparison between the calculated and measured results verified the mechanical model and the parameters used in the numerical simulation.

关 键 词：气压沉箱 竖井 现场监测 数值模拟 

分 类 号：TU472[建筑科学—结构工程]