建（构）筑物掏土纠倾法极限状态分析与风险控制研究

建（构）筑物掏土纠倾法是纠倾工程中最常用的方法，而基于塑性区理论的纠倾设计方法，建（构）筑物并不发生回倾，根本原因在于屈服与破坏是两个不同的概念，掏土孔周边塑性区的形成并不意味着掏土孔的破坏，即建（构）筑物并没有达到回倾的极限状态。本项目在塑性区研究基础上，基于数值极限分析方法，建立建（构）筑物回倾的极限状态方程。通过模型试验研究与数值分析相结合，研究不同岩土特性情况下掏土孔的破坏机制，阐明掏土孔破坏机制，建立掏土孔破坏准则。在此基础上，考虑场地土随机特性，建立土结相互作用的建（构）筑物纠倾数值分析模型，研究建（构）筑物掏土纠倾法回倾的极限状态，建立基于极限状态的设计方法；进行建（构）筑物回倾动态稳定全过程分析，确定回倾速率、回倾量及回倾方向等纠倾过程中的关键因素的界限值，并对纠倾过程实时监测，构建预警系统，实现纠倾过程风险的主动控制。

The under-excavation method is most commonly used in the rectification of buildings at present. However, the leaning building designed by the plastic theory method doesn't restore in the engineering projects. The main reason is that yielding is different from failure. The formation of the plasticity around the under-excavation hole doesn't equal to the failure of the excavation hole. This means that the limit state of restoring of the building has not obtained. In this regards, the proposal focuses on the study of the limit state of restoration of the leaning building using under-excavation method. The failure modes of the excavation hole are studied by model experimental and numerical researches, and the corresponding failure criteria are established. Further, a soil-structure interaction building rectification model considering the random field is established, and the limit state of building rectification is studied. In this context, the design method for building rectification is put forward based on the limit state analysis. Finally, the analysis of dynamic steady tilting process is done, and the thresholds of some key factors such as rectification rate, tilting value, rectification direction are determined. The information of rectification is detected during the project implication. Thus, a pre-warning system is established based on the limit value and detecting data. Therefore, the active risk management for rectification projects is ensured.