泸州长江二桥主桥结构技术特点

Technological Features of Structure in the Main Bridge of the Second Luzhou Changjiang River Bridge

泸州长江二桥主桥为一极不对称连续刚构。为平衡结构内力 ,在不平衡一侧设锚碇桥台。介绍该桥设计中涉及的一些技术特点 :为改善主墩及其基础受力 ,在主跨合龙前跨中施加顶推力和将钢沉井中心偏移墩中心以获得部分平衡弯矩 ;钢沉井嵌入基岩与桩基共同受力以达到经济目的。通过仿真计算 ,对箱梁的剪力滞后影响进行定量分析 ,以验证设计假定 ,同时对 0号块处的应力集中采取改善措施。

The Second Luzhou Changjiang River Bridge proper is a continuous rigid frame bridge with highly asymmetrical span arrangement. To balance the internal force, an anchor abutment is set in the asymmetrical side. To get better internal force of the main pier and the foundation, a jacking force is loaded on the middle span before closure. And the steel open caisson is eccentric to the pier to get partial balanced bending moment. To achieve an economical purpose, the steel open caisson is imbedded into bedrock to bear the load together with the pile foundation. Through simulation analysis, the certain magnitude of shear lag of the box beam can be obtained, and the stress concentration in the start element can be handled.