波形钢腹板箱梁嵌入式结合部的应力分布

针对波形钢腹板预应力混凝土箱梁桥嵌入式结合部应力分布问题,以宁波市百丈东路甬新河桥为背景,应用三维有限元方法进行应力分析。通过有限元计算模型,分析了不同荷载条件下结合部的应力分布特性,讨论了嵌入式结合部钢腹板纵向约束对应力分布的影响。理论计算结果表明,波形钢腹板混凝土箱梁的结合部应力比较小;弯矩作用下结合部应力主要是由截面的弯曲应力产生,应力集中不明显;剪力作用下在钢腹板插入口附近有应力集中现象,易发生混凝土开裂、钢板疲劳损失;采用钢板作为纵向约束措施对改善结合部的应力集中有一定效果。

Stress Behavior in Embedded Connection Zone of Box Girder with Corrugated Steel Webs

In order to investigate the stress distribution in embedded connection zone of prestressed concrete box girder with corrugated steel web,3-D finite element method was used with the background of Yongxin River Bridge over East Baizhang Road in Ningbo.The distribution characteristics of stress in connection zone were analyzed under different load cases,while the effect of longitudinal restraint to the stress distribution was discussed.The theoretical results showed four points:(1) the stress was small in connection zone;(2) the connection stress was mainly from section bending stress under moment effect and the local stress concentration effect was not significant;(3) the insert position of corrugated steel web occurred stress concentration under shear force of cross-section,where would easily happen to concrete crack and fatigue damage;(4) the effective of longitudinal reinforced steel plate was to improve the stress concentration in connection zone slightly.