深厚软弱覆盖层高承压水地质条件下锚碇受力变形及稳定性研究  

Research on Deformation and Stability of Anchorage Foundation under the Geological Conditions of Deep and Weak Overburden with High Confined Water

作　　者：姚宇 周彦锋 管维东 唐政 韩冬冬 YAO Yu;ZHOU Yan-feng;GUAN Wei-dong;TANG Zheng;HAN Dong-dong(Bridge Engineering Discipline,Tongji University,Shanghai 200092,China;China Design Group Co.Ltd.,Nanjing 210014,China;CCCC Highway Bridges National Engineering Research Centre Co.Ltd.,Beijing 100088,China)

机构地区：[1]同济大学桥梁工程系,上海市200092 [2]华设设计集团股份有限公司,南京市210014 [3]中交公路长大桥建设国家工程研究中心有限公司,北京市100088

出　　处：《公路》2025年第2期175-182,共8页Highway

摘　　要：张靖皋长江大桥北航道桥是主跨为1 208 m、缆跨布置为530 m+1 208 m+530 m的双塔单跨吊悬索桥。该桥南锚碇处软弱覆盖层以粉质黏土为主,厚度为43.8~50.5 m,粉质黏土层以下砂层均为承压含水层,承压水水头埋深在地面以下1.6~3.25 m,承压水水头高。南锚碇基础采用外径为90 m、墙厚为1.5 m的复合地基圆形地下连续墙基础,为满足基础底部地基承载力、抗渗性能、摩擦系数等的要求,基底以下28 m厚(局部加厚至30.5 m)进行地基加固处理。结合项目工程建设条件,对南锚碇基坑开挖地连墙支护结构受力变形、抗渗性能、抗滑和抗倾覆、地基承载力和锚点位移进行验算,结果均满足规范要求。所采用的锚碇基础及地基加固设计方案,可为类似深厚软弱覆盖层高承压水地质条件下桥梁锚碇结构类型和基础持力层的选择提供参考。The North Channel Bridge of Zhangjinggao Yangtze River Bridge is a double-tower singlespan suspension bridge with a main span of 1208 m and span layout of 530 m+1208 m+530 m.The weak covering layer at the south anchorage of the bridge is mainly silty clay,with a thickness of 43.8~50.5 m,the sand layer below silty clay layers are confined aquifers,the confined water head is buried 1.6~3.25 m below the ground,and the confined water head is high.The south anchorage foundation adopts a circular diaphragm composite foundation with an outer diameter of 90 m and a wall thickness of 1.5 m.In order to meet the requirements of foundation bearing capacity,impermeability,friction coefficient and other considerations at the bottom of the foundation,28 m thick below the foundation(locally thickened to 30.5 m)is subjected to foundation reinforcement treatment.In this paper,combined with the construction conditions of the project,the strength and deformation,anti-seepage performance,anti-sliding and anti-overturning,foundation bearing capacity and anchor point displacement of the diaphragm supporting structure excavated in the south anchorage foundation pit are checked and calculated,and the results all meet the requirements of the specification.The anchorage foundation and foundation reinforcement design scheme adopted in this paper can provide reference for the selection of bridge anchorage structure types and foundation bearing layers under geological conditions similar to deep and weak overburden with high confined water.

关 键 词：桥梁工程 张靖皋长江大桥北航道桥 软弱覆盖层 圆形地下连续墙 复合地基 深层地基加固 地基承载力 

分 类 号：U443.24[建筑科学—桥梁与隧道工程] U441.5[交通运输工程—道路与铁道工程]