论文部分内容阅读
基于地铁车站PBA工法施工实例,采用数值模拟方法分析给出了控制沉降变形的关键工序,总结了施工过程中采取的一系列施工措施和地下管线保护措施,通过施工监测揭示了沉降规律及变形控制重点.主要结论如下:1)PBA暗挖地铁车站施工沉降主要发生在小导洞开挖和扣拱施工阶段,这两个阶段是控制地表沉降的关键阶段;2)通过全断面注浆和后背回填注浆加固拱顶和管线之间的土体,可减少开挖后由于上部土体松散造成的沉降,有利于地下管线的保护;3)导洞开挖阶段和扣拱阶段地表累计沉降量分别为总控制值的55%和80%,是变形控制的重点.
Based on the construction example of subway station PBA, a series of construction measures and underground pipeline protection measures taken during the construction process are given by numerical simulation method. The settlement regulation and deformation control are revealed through construction monitoring The main conclusions are as follows: 1) Construction subsidence of PBA undercutting subway station occurred mainly in the construction of small pilot tunnel excavation and buckling arch construction, which are the key stages in the control of surface subsidence; 2) Through the full face grouting and back Backfill grouting to reinforce the soil between the vault and the pipeline can reduce the settlement due to the loosening of the upper soil after excavation, which is in favor of the protection of the underground pipeline. 3) The cumulative settlement on the surface during the excavation of the pilot tunnel and the buckling arch 55% of the total control value and 80%, is the focus of deformation control.