软土地基浅埋暗挖隧道数值模拟分析

Numerical Smulation of Shallow Tunnel Construction In Soft Soil Foundation

软土地基具有高压缩比、低力学性能、较强塑性,给浅埋暗挖隧道的施工带来诸多不利。本文拟采用数值模拟和现场监测对比的方法研究开挖过程中的位移沉降规律。文中以实际工程为背景,在给出工程地质条件、力学性质、相关参数的基础上,应用FLAC-3D软件对软土地基浅埋暗挖隧道的施工过程进行数值模拟。模型中,土体采用各向同性的弹塑性体,混凝土和锚杆采用弹性体,仅考虑自重应力,模拟得到了该条件下的变形云图。沿隧道中轴线两侧各20m范围内布置位移传感器监测其沉降值,并与数值模拟结果进行了对比。结果表明,二者的沉降曲线分布基本一致,数值模拟结果可以为类似工程的设计与施工提供借鉴和依据。

Due to soft soil foundation with high compression ratio, low mechanical property and strong plasticity, it brings many disadvantages to shallow buried tunnel construction. The method of the numerical simulation and field monitoring contrast is used in this paper to study displacement and settlement regularity in the process of excavation. In a setting of practical engineering, based on the engineering geological condition, chemical properties and related parameters, FLAC - 3 D software is used to numerically stimulate the construction process of soft soil foundation under the shallow tunnel. Soil in the model is with isotropic elastic plastic body, concrete and anchor using elastic body. Depending on soil＇ s self - weight stress, stimulation gets a deformation cloud picture, which is specifically meeting to this condition. Displacement sensors are placed within range of 20m along the tunnel axis, so that to monitor and get the sedimentation data. Compared with the results of numerical simulation, we finally find that the distribution of two settlement curves are basically the same. Also for similar project, this numerical simulation can provide worthy reference in the process of either design or the construction.