宜都长江大桥南岸重力式锚碇基础方案比选  

Foundation Selection for South-Bank Gravity Anchorage of Yidu Changjiang River Bridge

作　　者：罗勇 姜炜 易龙 任蒙[2] LUO Yong;JIANG Wei;YI Long;REN Meng(Hubei Jiaotou Yichang Expressway Construction Management Co.,Ltd.,Yichang 443300,China;CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430056,Hubei)

机构地区：[1]湖北交投宜昌高速公路建设管理有限公司,湖北宜昌443300 [2]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《桥梁建设》2023年第S01期127-133,共7页Bridge Construction

基　　金：湖北省交通运输厅科技项目(2017-538-2-9)。

摘　　要：湖北宜都长江大桥(原名白洋长江公路大桥)为主跨1000 m双塔单跨钢桁梁悬索桥,南岸(宜都岸)锚碇场地覆盖层厚约51.4 m,其中中粗砂混卵石、卵石层厚约46.9 m,属强透水、含水丰富地层,所含第四系孔隙水与长江水力相互连通,地下水位与长江水位基本持平。针对南岸锚碇工程区深厚富水砂卵石层的地质情况,提出沉井基础、地下连续墙基础和浅埋扩大基础方案,并从结构方案、施工方案、工程经济性等方面进行综合比选,推荐采用工程量最小、地下水位以上施工、经济性最优的浅埋扩大基础。浅埋扩大基础采用矩形平板基础,平面尺寸为101 m×71.5 m,基坑开挖深度为8.0 m。对该方案进行安全性验算,结果均满足设计和规范要求。The Yidu Changjiang River Bridge(originally known as Baiyang Changjiang River Bridge)in Hubei Province is a two-tower steel truss stiffening girder suspension bridge with a main span of 1000 m.The hanger cables are only arranged in the central span.The overburden at the south-bank anchorage(Yidu side)is about 51.4 m thick,where medium and coarse sands intersect with pebbles,and the thickness of the pebble layer is about 46.9 m,belonging to strongly pervious and water-rich stratum,where the pore water in the quaternary strata joins with the Changjiang River,and the pore water level is basically leveled with the Changjiang River water level.To address the geological conditions at the north-bank anchorage,the caisson foundation,diaphragm wall foundation and shallowly-buried spread foundation were compared from perspectives of structural configuration,construction challenges and engineering economy,and the shallowly-buried spread foundation was finally selected,because the working amount would be the smallest,the construction could be carried out above the groundwater level and the economy would be the best.The shallowly-buried foundation is a rectangular slab foundation,measuring 101 m×71.5 m,with the foundation pit excavation reaching 8.0 m deep.The safety checking of the structure demonstrates that the structure meets the design and code requirements.

关 键 词：悬索桥 锚碇基础 卵石层 沉井基础 地下连续墙基础 浅埋扩大基础 方案比选 安全性验算 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U443.1[交通运输工程—道路与铁道工程]