摘要
依托于南京地铁一号线南延线百家湖车站工程,利用经验证的数值模型和计算方法,研究了支护桩入土深度、不同型钢型号、型钢布置形式、不同支撑轴力、不同支撑水平间距等参数对SMW围护结构变形的影响。得出了各因素对围护结构变形的影响规律：支护结构的入土深度过小,会造成＂踢脚＂现象,在保证基底不失稳的条件下,当入土深度超过1.5H后,继续增加入土深度对减小支护结构水平位移的效果很小;不同形式的内插型钢布置对支护结构变形影响较大,型钢的型号对基坑变形影响较小;增加各道支撑预加轴力可以有效的减小围护结构变形,但施加过大的预应力会导致支护桩的过分后移,影响支护桩的强度,建议按照设计轴力的50%-80%取值;减小支撑水平间距是减小位移的有效方法,本车站工程支撑水平间距设为3.5-4 m为宜。
Based on Baijiahu subway station at Southern Extension of Nanjing Subway Line 1,this paper analyses effect of embedded depths of retaining piles,different types of section steels,different arrangement of section steels,different strut axial forces and so on to the deformation of the SMW wall by validated model and calculation method. The conclusions of the numerical test are as follows： Insufficient embedded depth may cause the SMW wall damage. When embedded depth exceed1. 5H,increasing embedded depth of the wall again shows no benefit to preventing structural deformation. According to different disposition forms of the section steel,the deformation of the SMW wall changes obviously. The influence caused by the change of section steel type to the deformation is insignificant. Increasing brace pre axial force can effectively control the wall displacement. But Excessive force can lead to excessive displacement backward and influence the strength of supporting pile. the optimum pre axial force is50% to 80% of design value. Reducing the horizontal spacing of the steel support can effectively reduce displacement of the wall,the optimum horizontal spacing is 3. 5m to 4m for Baijiahu subway station.
出处
《地下空间与工程学报》
CSCD
北大核心
2015年第4期1066-1071,1079,共7页
Chinese Journal of Underground Space and Engineering
基金
江苏省自然科学基金项目(BK2011406)
关键词
SMW工法
深基坑
监测
数值模拟
变形
预加轴力
SMW engineering method
deep foundation pit
monitoring
numerical simulation
deformation
brace pre axial force
