With the increase of traffic flow, the road carrying level needs to be improved, more and more bridges need to be demolished and rebuilt. The primary principle of bridge demolition is safety first, but collapse accidents caused by improper construction occur from time to time. This paper takes Qingshuihe Bridge as the research object, and studies the distribution law of structural residual bearing capacity during bridge demolition by finite element numerical simulation method, so as to provide theoretical support for the safe demolition of bridges. Based on ABAQUS finite element software to establish the bridge model, using explicit finite element analysis method, the structure along the z-axis equally spaced division of 30 free slices, analyzed the distribution of internal forces and residual bearing capacity of the bridge structure under different demolition time. The study shows that: with the increase of demolition time, the maximum value of internal force in Fx direction reaches 3260kN, which occurs at the number of slices 15; the internal force in Fy direction shows a symmetric structure about the number of slices 15, with the maximum value of 8.83×104kN; the residual bearing capacity of the structure decreases from the initial 194896kN to the 144676kN in 240min, which is the rule of change of the double-exponential decay function. By comparing the tests of specimens FCD-1, FCD-2 and FCD-3 with the finite element simulation, the model errors were 9.2%, 4.3% and 5.2% respectively, which verified the accuracy of the model. This study provides a reference basis for the structural safety control during the demolition process of similar bridges such as the Clearwater River Bridge.
