Construction verification of a cable-stayed arch cooperative bridge in China

The mechanical properties of cooperative system bridges are complex. This paper describes the construction monitoring and load tests of a cable-stayed and arch cooperative bridge. The cable force, girder stress and arch alignment were monitored during construction to ensure the safety of the bridge structure and attain the intended internal force state in the completed bridge. Static and dynamic load tests were performed after completing the bridge to test its bearing capacity. The construction monitoring observations indicated that the cable force and suspender force change of the bridge during construction were generally consistent with theoretical calculations. The measured cable force of cable C01 was between 2155 and 3085 kN, and the measured value of suspender LS15 was between 980 and 1250 kN; these values conform to the laws of mechanics. The load test results demonstrated that the maximum deflection of the mid-span section of the girder was 5.8 mm, which was less than the theoretical value (6.3 mm). The measured impact coefficients of the bridge under four sets of working conditions based on dynamic load testing were similar to the computed results. These results confirm that the girder has sufficient structural stiffness.