桩墙式挡土结构的变形模式及其识别

基坑挡土结构的侧向变形数据是反映基坑工程安全与环境控制的重要指标之一。由于现场地质条件与施工过程的复杂性,实际发生的挡土结构变形与设计计算结果在变形值大小及分布形态上存在差异。基于工程经验及挡土结构的受力变形原理,总结归纳了挡土结构典型的变形模式及其特征,在此基础上,基于贝叶斯概率准则实现对挡土结构实测变形的整体模式及局部模式识别。依此不仅可判明实际施工工况的变化或可能存在的工程缺陷,同时由于其可以提供非正常变形模式的预警,从而弥补了现行规范中仅以变形大小和速率为预警指标的不足,对于提高信息化施工的准确性和及时性具有重要意义。

Deformation patterns of retaining structures in excavation and their recognition

The deformation data of retaining structures are considered to be one of the important indice to evaluate the safety and environmental impacts of excavation projects. However, because of the complexity of geological conditions and construction process, it is difficult to reflect the real stress condition with accurate value and shape of the deflection curve obtained by analytical solutions. Typical patterns of deflection curve are proposed based on the previous experience, soil mechanics and corresponding construction conditions. A method for pattern recognition of deflection curve based on the Bayesian probability theory is used to indicate the potential defects of retaining walls, and it has significance for improving the accuracy and efficiency of the informational construction. The proposed method is proved to be feasible by an actual project.