深基坑施工对高架基础的变形影响及控制研究  

Influence of deep excavation on deformation of elevated bridge foundations and countermeasures

作　　者：丁勇春 王建华[2] 

机构地区：[1]中交第三航务工程勘察设计院有限公司,上海200032 [2]上海交通大学,上海200240

出　　处：《土木工程学报》2012年第7期155-161,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(50679041)

摘　　要：以上海某下穿高架并紧邻高架基础的地铁车站深基坑为背景,采用简化分析、三维数值模拟及原位监测等手段,对复杂环境下深基坑施工对邻近高架基础的变形影响及变形控制措施进行研究。采用基坑开挖环境影响简化分区图并根据保护对象与基坑的相对位置关系,确定高架桩基的影响类型。根据混凝土结构裂缝控制要求,采用等代荷载法普通梁模型建立由桩身应力控制的桩基及基坑围护结构变形控制指标。通过建立三维整体计算模型,动态预测基坑围护结构及高架桩基的变形性态。主要监测结果与上海地区其他工程的对比分析表明,本工程采取的基坑围护结构及支撑体系调整、坑内地基加固及结构局部逆作等一系列变形控制措施,不但有效控制基坑自身的变形,也有效保护邻近高架基础的安全。For a deep excavation for underground metro station adjacent to elevated bridge pile foundations, simplified analysis,3-D numerical simulation and in-situ monitoring are employed to study the behavior of the excavation and its influence on deformation of the nearby pile foundations. Based on the simplified partition diagram of environment impact of deep excavation according to the relative spatial relationship of the pile foundations and the excavation, the influence types of pile foundations and the corresponding protection are presented. The deformation control criteria of retaining structures of excavation and pile foundations are established based on crack control requirement of concrete pile using the equivalent load method. The comparison of the measured data with the other related projects in Shanghai soft soil area shows that these deformation control measures adopted in this project, which include the adjustment of retaining structure scheme and strut system, inside ground improvement and top-to-down construction of partial middle slab, can restrict of the deformation of the excavation and ensure the safety of the nearby elevated bridge pile foundations.

关 键 词：软土 地铁车站 基坑 钻孔灌注桩 地下连续墙 桩基 变形控制 

分 类 号：TU473.2[建筑科学—结构工程]