摘要
西堠门公铁两用大桥主桥采用主跨1488 m公铁同层布置分离式钢箱梁斜拉-悬索协作体系桥。结合该桥册子岛侧锚碇区域地形与地质条件,对嵌岩重力锚和隧道锚进行综合比选,最终采用施工风险小、耐久性好、养护工作量小的嵌岩重力锚。为增加锚碇抗滑稳定性,基底后端设计为台阶型,并设置2道嵌岩墙;为减小基坑开挖量,锚碇底部左、右两侧及尾部设为斜坡状。采用ANSYS软件建立岩石-混凝土接触有限元模型,对锚碇受力性能、地基应力及抗滑稳定性进行计算分析。结果表明:锚碇前锚室底板与支墩、顶板与锚体等连接部位及后锚室锚后牵拉区均存在较大拉应力,需针对性配筋;地基应力及抗滑稳定性均满足要求;设置台阶型锚体对抗滑稳定性贡献显著。
The main bridge of Xihoumen Rail-cum-Road Bridge is a combined cable-stayed and suspension bridge with a main span of 1488 m.The main girder comprises separated steel boxes that forming a deck accommodating both highway and railway.Given the topographical and geological conditions at the anchorage site on the Cezi Island,the options of gravity rock-socketed anchorage and tunnel anchorage were analyzed and compared,and the gravity rock-socketed anchorage was finally chosen because of its excellence in construction risk control,durability and future maintenance.To improve the anti-slipping stability of the rock-socketed anchorage,the rear of the anchorage base is designed as steps,where two rock-socketed walls are also installed.To reduce the excavation volume of the foundation pit,the right and left sides as well as the back of the anchorage base are treated as slopes.The rock-concrete contact finite element model was built by ANSYS,to calculate and analyze the mechanical property,foundation stress and anti-slipping stability of the anchorage.The results demonstrate that great tensile stresses exist in the connections between the base plate and buttresses in the front anchor chamber,the connections between the roof and anchor body and the traction area behind the anchor plugs in the rear anchor chamber,whereby reinforcement should be tailored for specific locations.The foundation stress and anti-slipping stability of the anchorage can meet the requirements.The contribution of steps to the anti-slipping stability of the structure is significant.
作者
邱远喜
肖海珠
刘俊锋
QIU Yuan-xi;XIAO Hai-zhu;LIU Jun-feng(China Railway Major Bridge Reconnaissance&Design Institute Co.,Ltd.,Wuhan 430056,China)
出处
《桥梁建设》
EI
CSCD
北大核心
2020年第S02期9-15,共7页
Bridge Construction
基金
中国中铁股份有限公司科技研究开发计划项目(2019-专项-01)。
关键词
斜拉-悬索协作体系桥
嵌岩重力锚
结构设计
岩石-混凝土接触分析
结构应力
基底应力
抗滑稳定性
有限元法
combined cable-stayed and suspension bridge
gravity rock-socketed anchorage
structural design
rock-concrete contact analysis
structural stress
foundation stress
anti-slipping stability
finite element method
