软土地层双线隧道地表沉降计算公式修正

由于双线隧道存在复杂的耦合作用,盾构施工引起的地表沉降规律极为复杂,所以准确计算地表沉降较为困难。本文基于Peck公式和Chapman修正参数,考虑先行隧道的施工影响和双线隧道的相对位置关系,通过参数的经验量化,建立了双线隧道地表沉降的计算公式。此外,依托苏州市轨道交通S1号线工程,讨论公式在不同土层中的适用性及参数取值范围,在此基础上采用PLAXIS 3D有限元软件对双线隧道盾构施工进行了数值模拟。结果表明：在软土地层中进行盾构施工,应用本文修正公式计算得到的地表沉降值与数值模拟和现场实测结果均较为吻合。修正公式考虑了双线隧道的位置信息,可以定量反映隧道埋深和双线隧道间距对地表沉降的影响。该研究可为软土地区双线隧道盾构施工沉降计算提供参考。

Correction of surface settlement prediction formulafor twin tunnel with soft ground

Due to the complex coupling effect of the double-line tunnel, the surface settlement pattern caused by the shield construction is extremely complicated, so it is more difficult to predict the surface settlement accurately. In this paper, based on Peck"s formula and Chapman"s correction parameter, the prediction formula for surface settlement of the twin tunnel is established through the empirical quantification of the parameters considering the construction influence of the prior tunnel and the relative position relationship of the double-line tunnel. In addition, the applicability of the formula in different soil layers and the range of parameter values are discussed by relying on the Suzhou Railway Line S1 project, and on this basis, the numerical simulation of the double-line tunnel shield construction is carried out by using PLAXIS 3D finite element software. The results show that the surface settlement values calculated by applying the modified formula in this paper are in good agreement with the numerical simulation and field measurement results for shield construction in soft ground. The formula in this paper takes into account the location information of the twin tunnel, which can quantitatively reflect the influence of the tunnel depth and the spacing of the double-line tunnel on the surface settlement, and the settlement curve fitted by the modified formula shows a normal distribution. The study can provide a reference for the calculation of settlement in double-line tunnel shield construction in soft soil areas.