某地铁车站洞桩法施工变形和结构受力分析

Analysis of the Deformation and Structural Stress of a Metro Station Constructed by Pile-Beam-Arch Method

  • 摘要: 洞桩法(PBA)作为一种新型的地铁车站施工工法已得到了成功应用,但缺少对PBA法地铁车站施工引起的地表沉降和结构受力的综合研究。文章以某洞桩法施工地铁车站为工程背景,采用数值模拟与现场监测相结合的方法,对洞桩逆作法不同施工阶段引起的地表沉降和车站结构受力进行分析。研究结果表明:导洞开挖和扣拱施作对地层的扰动较大,因此有必要对地层进行预加固处理(如超前管棚+注浆),进而严格控制地面沉降总量;围护桩轴力时程曲线可分为3个阶段,即快速增长阶段、缓慢增长阶段、稳定持平阶段;实测和计算得到的沉降值变化规律基本吻合,地表沉降最大值均发生在车站中轴线上方,符合Peck沉降槽理论。

     

    Abstract: As a new construction method of metro stations, the Pile-Beam-Arch method (PBA) has been success? fully applied in the practical engineering, but there is a lack of comprehensive researches on the surface settlement and structural stress of metro stations caused by PBA method construction. Taking a metro station constructed by Pile-Beam-Arch (PBA) method as the engineering background, this paper analyzes the surface settlement and the structural stress of the metro station in different construction stages of PBA top-down construction method, by means of the combination of numerical simulation with on-site monitoring. The research results show that the excavation of the pilot tunnel and the construction of the supporting arch have great disturbance to the ground, it is necessary to pre-reinforce the ground (such as advance pipe-roof + grouting), so as to strictly control the total amount of ground settlement. The time-history curve of the axial force of retaining piles can be divided into three stages: rapid growth stage, slow growth stage, and stable stage. The variation laws of measured and the calculated settlements are basically consistent, and both the measured and calculated maximum surface settlement occur above the central axis of the station, which is in line with the Peck settlement trough theory.

     

/

返回文章
返回