Mechanical Property Analysis of Light Railway Trough Girder Subjected to Combined Bending and Torsion

The application of reinforced concrete trough girders in urban light railway reduces the noises that affect the neighborhood, which also alleviates the traffic problems. However, constraint torsional problems will be caused by the swaying force of the train; therefore more reasonable reinforcement methods should be used. Girders under constraint torsion were researched to interpret their stress states and mechanism of fractures based on the limit state analysis method. Warping, normal stress, and shearing strength distributions are interpreted, and a new mechanics analysis method is put forward. Then the warping moment is translated into moments by integrating the warping normal stress in the webs and plate separately and doing derivations of the integral. Combined with the bending moment bearing capacity calculation formula, the torsional limit bearing capacity formula for trough girders under constraint torsion is primarily established. The ultimate torque from the formula agrees with both the test results in the existing references and the simulated results from ABAQUS software. The results exhibit significant guidance for engineering applications.