地铁车站洞桩法施工对地层沉降影响研究

结合大连地铁松江路车站的工程条件,运用有限元软件MIDAS-GTS建立车站结构-地层三维模型,得出了地表沉降、沉降槽以及塑性区的发展规律.结果表明:地表沉降依照施工过程具有阶段性,导洞施工是控制地表沉降的关键阶段;最大地表沉降及最终地表沉降均符合60mm的控制基准,故洞桩法在控制地表沉降方面是有效的;沉降槽形态及深度受群洞效应影响,且与结构埋深及施工方式有密切关系;塑性区主要产生于导洞阶段,洞桩法基本抑制了塑性区的发展.

Research on ground settlement of metro station construction by PBA method

Combined with engineering conditions of Songjiang Road metro station in Dalian, a three-dimensional model of underground station was built using finite element software MIDAS-GTS, and the development tendencies of surface settlement, settlement trough and plastic zone were analyzed. The analytical results show that the surface settlement has obvious stages and the construction of pilot tunnel is the key phase to control surface settlement. Furthermore, the maximum surface settlement and the final surface settlement both meet the control criterion 60 mm, so PBA (pile-beam-arch) method is effective to control surface settlement. And the mode and depth of the settlement trough are affected not only by multi-tunnel effect, but also by burial depth and construction mode. Finally, plastic zone generates at pilot tunnel phase, PBA method could control the development of plastic zone effectively.