云南镇雄呢噜坪大桥总体设计

The Overall Design of Neluping Bridge in Zhenxiong, Yunnan

呢噜坪大桥位于云南省镇雄县,连接易地扶贫安置点与城市中心,是镇雄发展交通系统的控制性工程。呢噜坪大桥桥位处地形是V字形山谷,考虑经济性与施工快捷性,采用(6×40)m的简支预应力混凝土T梁桥。上部结构为结构简支、桥面连续的预应力混凝土T梁,下部结构桥墩为空心薄壁墩和实体板墩,桥台为U型重力式桥台和轻型桥台。桩基为直径1.5 m和2.0 m的钻孔灌注嵌岩桩,持力层为中风化玄武岩层。桥墩施工采用滑模施工,T梁采用架桥机架设安装。该桥在设计中采用了在T梁底和盖梁顶设置剪力销等措施,满足结构地震作用下限位和大纵坡抗滑移的需求。

Neruping Bridge is located in Zhenxiong County,Yunnan Province,connecting the poverty-alleviation relocation resettlement site and the urban center,which is a control project for the development of the transportation system in Zhenxiong.Because the terrain of the bridge site is a V-shaped valley,a(6×40)m simply-supported prestressed concrete T-beam bridge is adopted considering the economy and construction speed.The superstructure is a prestressed concrete T-beam with simply-supported structure and continuous bridge deck,the substructure piers are hollow thin-walled piers and solid plate piers,the abutments are U-shaped gravity abutments and lightweight abutments.The pile foundation is the bored socketed pile with a diameter of 1.5 m and 2.0 m,and the bearing layer is a medium-weathered basalt layer.The construction of the pier is carried out by slip form construction,and the T-beam is erected and installed by bridge erecting machine.In the design of the bridge,measures such as setting shear pins at the bottom of T-beam and the top of capping beam are adopted to meet the requirements of position limit of the structure and the anti-slip of large longitudinal slope under seismic action.