地铁施工引起的建筑物扭曲变形分析

Analysis of tunnelling-induced twist deformation of buildings

隧道施工或深基坑开挖过程中会引起地面建筑物或其他结构产生复杂的变形,长期以来,对建筑物的弯曲或剪切变形都进行过一些研究,但是一般都忽略了结构的扭曲变形。事实上,由于地层的位移,会引起附近的各类结构普遍承受不同程度的扭曲变形。本文讨论了建筑物某一个平面的扭曲变形(例如基础平面,或建筑物的某一个立面)问题。首先给出了一个平面扭曲变形的数学定义,然后基于力学分析和受力推导,得到了平面变形扭曲的量化表征和计算方法。进一步在对实测资料分析的基础上,探讨在某些简化假定条件下,建筑物基础板的扭曲变形分析方法。最后以伦敦伊丽莎白大厦(E lizabeth House)为例,采用本文所提出的方法具体量化分析了该建筑物在地铁隧道施工过程中产生的扭曲变形,并对扭曲变形的规律进行了探讨,对扭曲变形对结构安全的影响进行了分析。

Buildings and other structures may have to bear ground movements caused by construction of subway tunnels or other underground structures in the vicinity. In assessing building damages it is common practice to consider only structural bending or shearing, while ignore the twist deformation of structures due to the theoretical complexity and lack of relevant measurement data. However, twist deformation commonly occurs in buildings under excavation-induced ground movements and thus important to the safety of the structures. The mathematical and physical definitions of the twist deformation of a building plane are discussed, and a calculation method is proposed through a theoretical analysis of the building deformation modes. This method is assessed through a study of the measurement data for the Elizabeth House in London, which was monitored extensively during the construction of a nearby subway tunnel. Based on the case study, characteristics of building twist deformation are discussed.