沪宁扩建桥梁极限承载能力实桥试验研究

Practical Experimental Study on Ultimate Bearing Capacity of Actual Bridge in Huning Expressway Extension Project

实桥破坏性试验,对于真实了解桥梁在塑性阶段的力学行为、损伤发展过程、刚度退化规律、塑性铰、内力重分布以及破坏形态等方面具有仿真分析和缩尺模型试验所不可替代的作用,但由于耗资巨大,组织复杂,要求高、难度大而很少得以进行。利用沪宁高速公路江苏段扩建改造过程中部分桥梁拆除重建的难得机遇,对其中一座三跨连续箱梁桥和一座简支T梁桥开展了国内首次公路实桥承载能力极限状态破坏性试验,着重研究了桥梁由弹性、弹塑性直至破坏全过程中的受力机理、破坏过程、破坏形态以及刚度退化规律等重要问题。

Destructive experiments on actual bridges have advantages over numerical simulation and model test on understanding the plastic mechanic behavior, damage evolution, stiffness deterioration, plastic hinge occurrence, force redistribution of bridges.However,destructive experiments are seldom conducted due to it＇s high cost.During the time of extension of the Huning expressway,some bridges are dismantled and are used in destructive experiments.This paper introduces the destructive ultimate load capacity test on a three-span continuous box- girder bridge and a simple T beam bridge.It focuses on the variability of bridge dynamic characteristics,damage scenarios,damage evolution and the correlations between damage and dynamic characteristics aiming at researching the feasibility of vibration-based damage detection method.