盾构隧道施工时地层沉降模型试验研究

Large-scale Physical Modelling on the Ground Settlement Induced by Shield Tunneling

随着我国经济的发展,地铁已成为改善城市交通拥堵状况的主要途径之一。但地铁隧道的施工却又不可避免地带来诸多安全隐患,例如,由于隧道施工时土层的沉降,导致管线的破裂。本文旨在通过室内大型模型试验研究地铁盾构隧道开挖时上覆土层的沉降分布特征,分别测定不同深度地层的沉降值,通过对试验数据的分析与整理,得出沉降沿地层深度的分布规律。结果表明:同一深度的地层沉降基本符合peck公式曲线;地层沉降槽的宽度值i不会随沉降量的增加而变化,只与该地层的所处深度有关;并根据试验得出沉降槽宽度i的经验公式。

With the rapid development of China,subway is becoming a main method to solve the traffic jam in huge cities. However,a number of problems have been induced by the subway construction,such as the pipeline failure caused by the ground settlement. In this study,large-scale modeling was used to evaluate characteristics of the settlement caused by shield tunneling through measuring the settlement at different depth. It is demonstrated that the settlement trough at a specific depth can be fitted using normal distribution curve. The parameter i presenting the width of the settlement trough would not increase with the settlement increase but only depends on the depth of the settlement trough. An empirical formula for the width of the settlement trough was proposed based on the test results.