盾构隧道施工对邻近建筑物破坏风险初步评估

隧道开挖会引起地表和深层土体沉降,研究地层移动规律对于确定建筑物风险等级和保护邻近建筑物具有重要意义。首先,基于Peck公式并考虑深层土体横向沉降槽引起建筑物的沉降和倾斜,得到了建筑物风险区计算模型;然后,通过改变参数,分析了隧道直径D、基础埋深d以及地层损失率V_L等对建筑物风险区大小的影响规律,推导得到了风险区的边界值(C/D)₀和(x/D)₀。最后,根据不同风险控制等级,提出了隧道开挖对邻近建筑物风险的初步评估方法,并将风险区划分为4个部分。研究结果表明:所提风险区划分方法仅需隧道直径D、地层损失率值V_L、隧道埋深Z以及沉降槽宽度系数i即可实现,具有简单、高效等特点,且能够反映不同参数对风险区变化的影响。研究结果可为隧道开挖对邻近建筑物安全影响初步判断和风险预估提供参考。

Preliminary Risk Assessment of Shield Tunnelling-incluced Damage to Adjacent Buildings

Tunnel excavation will cause surface and subsurface settlement. Studying the law of formation movement is of great significance to determine the risk level of buildings and protect adjacent buildings.Firstly,the calculation model of risk zone is obtained based on Peck's formula considering the settlement and inclination of buildings caused by subsurface settlement trough. Secondly, the influence rules of tunnel diameter D, foundation depth d and ground loss ratio V_L on the size of the building risk zone are analyzed, and the boundary values (C/D)₀ and (x/D)₀ of risk zone are deduced. Finally, according to different risk control levels, a preliminary risk assessment method for adjacent buildings during tunnel excavation is proposed, and the risk zone is divided into four zones. The risk zoning method proposed in this paper is simple and highly-efficient as only four parameters are needed: tunnel diameter D, ground loss ratio V_L, tunnel's buried depth Z and coefficient i of settlement trough width. The method also reflects the influence of different parameters on the change of risk zone. The research findings provide reference for preliminary judgment and risk prediction of the impact of tunnel excavation on adjacent buildings' safety.