盾构法隧道施工引起的土体超孔隙水压力消散,会导致工后地表继续沉降。在前人研究基础上,提出了隧道周围土体的初始超孔隙水压力计算方法。采用分层总和法,计算由于扰动区内土体超孔隙水压力消散引起的地表固结沉降量,结合施工阶段地表沉降量,叠加得到总的工后横向地表沉降。提出了固结开始t时刻的地表总沉降量计算方法,研究了地表沉降速率随时间的变化。算例分析结果表明:本文方法计算得到的横向地表沉降曲线符合正态分布规律,与实测值吻合;地表总沉降速率的发展也与实测沉降速率曲线相符。
Due to the excess pore water pressure dissipation, the post-construction surface settlement will be continued caused by shield tunneling. Based on past research, a calculation method of initial excess pore water pressure around the tunnel is put forward. By using layerwise summation method, the surface consolidation settlement can be got within disturbed region of excess pore water pressure dissipation. Combining with the surface settlement in tunnel construction phase, total transverse post-construction surface settlement is obtained. The total surface settlement after soil consolidation is proposed;and surface settlement rate changes over time are also studied. As is shown in analytical calculation, the calculated results of the transverse surface settlement curves are in good agreement with the field data; and they are also in accordance with the normal distribution law. The development of total surface settlement rate is in good agreement with the field data.