施工栈桥在深基坑工程中应用技术研究

Technical study on application of trestle bridge in deep foundation pit engineering

沿海城市深基坑工程普遍面临周边场地狭小,地下多为软弱土层,基坑施工期间围护体变形随基坑暴露时间延长而持续增长的情况。通过合理设置施工栈桥后可以安全快速地开挖土方,方便后期地下结构施工,加快地下工程施工进度,从而减少基坑施工对周边环境带来的不利影响。但如何合理地将施工栈桥与基坑支护体系设计相结合,现行规范仍需进一步研究,如施工栈桥上使用荷载的限值大小、工况组合及栈桥尺寸、平面合理范围布置等问题。借助于上海市区近年完成的若干基坑工程,对上述问题进行数据统计分析,供今后栈桥设计施工时进一步研究参考。

Deep foundation pit engineering in coastal cities is generally faced with the narrow surrounding area,the underground strata is mostly composed of soft soil,and the deformation of the enclosure during the construction of foundation pit is increasing with the prolongation of the exposure time of the foundation pit. The earthwork can be excavated safely and quickly after the reasonable adjustment of trestle bridge,which facilitates the construction of the subsequent underground structure and speeds up the construction progress of the underground engineering,thus reducing the unfavorable influence on the surrounding environment of the foundation pit construction. But how to combine the design of the trestle bridge and the foundation pit support system reasonably,the current norms still need to be further studied,such as load limit,load combination,lane dimension and reasonable plain layout of the trestle bridge,e. t.. With reference to several foundation pit projects completed in Shanghai city in recent years,makes a statistical analysis of the above problems was made for further research and reference for the design and construction of trestle bridge in the future.