基于单因素分析的某深基坑优化设计  

Analysis of Optimal Design for Deep Foundation Pit with Single-factor

作　　者：杨将[1] 彭加强[1] 周奇辉[1] 卢慈荣[1] 

机构地区：[1]中国水电顾问集团华东勘测设计研究院,杭州300014

出　　处：《铁道工程学报》2009年第3期84-88,共5页Journal of Railway Engineering Society

摘　　要：研究目的：深基坑工程涉及影响因素多,变量间作用关系复杂。通过本研究,拟找到一个施工便捷、结构安全、经济合理的支护体系。研究结论：基于仿真分析采用单因素分析方法结合具体地铁基坑工程分析了支护系统围护桩刚度、支撑刚度、围护桩的入土深度对基坑工作性状的影响,得出结论如下：（1）适当地增加围护桩墙和支撑的刚度可以减小围护结构的变形,提高基坑的稳定性,但如果刚度过大会使支撑轴力过大,导致支撑失稳破坏,还会造成工程造价的提高;（2）围护桩入土深度应控制在合适的范围内,一般在基坑（开挖）深度的1.2~1.4倍之间。入土深度过小、桩身整体变形过大使基坑破坏,入土深度过大,对变形的控制效果不明显,会增加工程造价;（3）对围护桩径进行优化,得出在800桩径的围护结构作用下地表沉降满足控制要求,且能极大地降低工程成本。Research purposes：Deep foundation pit construction involves many factors and among which the inter-relationships are complicated,so it is necessary to do the research on seeking a money-saving bracing system with rational structure for rapid reconstruction.Research conclusions：Combined with a special subway excavation project,this paper analyzes the guard pile stiffness as support system,support stiffness and embedded depth of guard pile for foundation pit with single-factor analysis based on the simulation analysis.It concludes：（1）The deformation of exterior-protected construction can be reduced and the stability of foundation pit can be enhanced through improving the guard pile stiffness and support stiffness.However,if the stiffness is too much,the axial force becomes big,resulting in the support unstable and damaged and increase of the construction cost.（2）The depth of guard pile should be controlled in the range from 1.2 h to 1.4 h.If the embedded depth is less,the deformation of the pile becomes large,resulting in the foundation pit damage.If the embedded depth is too much,the effect on deformation control is not obvious,resulting in increase of the construction cost.（3） After Optimization of the pile diameter,the deformation control can meet the requirement of ground subsidence and the construction cost can be lowered much under the effect of guard pile with diameter of 800.

关 键 词：深基坑 仿真分析 优化设计 单因素分析 

分 类 号：TV551[水利工程—水利水电工程]