连续梁桥预制PC小箱梁裸梁加载试验研究

Static load test research on PC precast beams of small-box beam in continuous girder bridge

为评估某桥左幅5-3端跨中梁(小箱梁)的实际承载能力,验证桥梁设计可靠性和施工质量。基于静载试验的方法,研究正载工况下该小箱梁控制截面的应变和挠度值,并与设计值进行校验。分析结果表明:在试验荷载作用下,该小箱梁各测试截面的挠度实测值均小于理论计算值,其挠度校验系数为0.73~0.82,结构刚度性能满足规范要求;各测试截面的应变实测值均小于理论计算值,应变校验系数为0.78~0.88,结构强度满足规范要求;试验加载过程中未出现异常现象;加载前及荷载作用下,小箱梁测试截面附近区域内,未发现新增的肉眼可见的横向裂缝,表明该小箱梁结构静力性能满足设计荷载的正常使用要求。

In order to evaluate the actual bearing capacity of the left 5-3 end span middle girder(small box girder)of a Bridge,and verify the design reliability and construction quality of the bridge.The strain and deflection values of the control section of the small box girder under normal load are studied and verified with the design values based on the method of static load test.The test results show that,under the test load,the measured deflection value of each control section of the small box girder is less than the theoretical value,the deflection calibration coefficient is between 0.73 and 0.82,and the structural rigidity meets the design requirements.The measured strain value of each control section is less than theoretical value,the strain calibration coefficient is between 0.78-0.88,and the structural strength meets the design requirements.The test small box girder has undergone a static test loading with a load efficiency of 0.99,and no abnormal phenomena occur during the test loading process.Before loading and loading under the action,no new visible transverse cracks were found in the area near the test section of the small box girder.That is,the static performance of the test small box girder structure meets the normal use requirements of the design load.