变宽连续梁桥腹板预应力锚头混凝土破裂影响

Influence of concrete rupture on web prestressed anchor head of widened continuous girder bridge

为分析施工过程中腹板预应力锚头混凝土破裂修复后连续箱梁结构整体受力是否满足设计要求,本文以某市过江通道及连接线工程为例,分析东侧引桥上层第三联变宽连续箱梁腹板预应力锚头混凝土破裂产生的原因和导致的影响,并基于Midas Civil有限元软件,结合现场实际处理情况进行数值分析,根据得出的预应力损失对成桥状态的影响量值与设计成桥状态进行数值比较。结果表明:锚头混凝土破裂造成主梁弯矩、正应力、主应力和竖向位移的影响量值,代入设计使用阶段正截面抗弯验算、正截面抗裂验算、斜截面抗裂验算、正截面应力验算和斜截面应力验算均能满足设计规范要求。

In order to analyze whether the overall force of the continuous box girder structure meets the design requirements after repairing the ruptured concrete of the web prestressing anchor head during the construction process,the engineering of city river crossing and connecting line are taken as example,the causes and resulting effects of the ruptured concrete of the web prestressing anchor head of the third link of variable widthed continuous box girder on the upper level of the east approach bridge are analyzed.Numerical analysis is carried out based on Midas Civil finite element software combined with the actual treatment at the site,and numerical comparison is made between the derived values of the impact of prestressing loss on the completion state and the completion state design.The results show that the influence values of bending moment,positive stress,principal stress and vertical displacement of the main girder caused by anchor head concrete rupture can meet the design specification requirements by substituting the positive section anti-bending test,positive section anti-cracking test,diagonal section anti-cracking test,positive section stress test and diagonal section stress test in the design use phase.