全地下泵站深基坑开挖支护结构安全稳定性分析

Safety and Stability Analysis of Support Structure for Deep Foundation Pit Excavation in All-Underground Pumping Station

针对当前使用基于开挖施工监测与数值模拟分析、基于“墙-撑-锚”组合支护体系变形模拟分析方法,易受由于地基中大量存水导致塌陷从而使数值模拟结果不精准的问题,进行全地下泵站深基坑开挖支护结构的安全稳定性分析。以空港污水处理厂迁厂输水管线及泵站工程项目为例,阐述深基坑支护技术及常用的支护结构类型,着重从深基坑支护的整体抗滑稳定性、基底抗隆起稳定性和抗管涌特性分析全地下式泵站深基坑支护的安全稳定性,并通过实例验算了地下连续墙作为全地下式泵站的基坑支护是可靠的;在结构失稳情况下,中心隆起程度模拟结果与实际数值最大相差0.06 mm,模拟结果具有精准性。

The deformation simulation analysis method based on excavation construction monitoring and numerical simulation analysis,and the deformation simulation analysis method based on the“wall-supportanchor”composite support system are easily affected by a large amount of water in the foundation,and the numerical simulation results are inaccurate due to collapse.To address this issue,the safety and stability analysis of the deep foundation pit excavation support structure of the all-underground pump station is proposed.Taking the relocation of the airport sewage treatment plant and the pump station project as an example,this paper introduces the deep foundation pit support technology and the commonly used support structure types,and analyzes the safety and stability of the deep foundation pit support of the all-underground pump station from the overall anti-sliding stability of the deep foundation pit support,the anti-uplift stability of the base and the anti-piping characteristics,and through an example,checks that the underground diaphragm wall is reliable as the foundation pit support of the allunderground pump station;in the case of structural instability,the maximum difference between the simulation result and the actual value of the center bulge degree is 0.06 mm,with accurate numerical simulation results.