Construction Verification of Under-bearing Arch Bridge Based on Construction Monitoring and Test

In this paper, a bottom-bearing arch bridge is taken as an example to carry out the bridge construction monitoring and load tests. In order to ensure the safety of the arch bridge structure in construction and reach the internal force state of the bridge, in the construction monitoring, the construction process of the main girder type and stress, construction error and safety state is monitored. At the same time, in order to verify whether the bridge can meet the design requirements, static and dynamic load tests are carried out after the bridge is completed. The results of construction monitoring show that the stress state of the structure during the construction process is basically consistent with the theoretical calculation and design requirements, and both meet the design and code requirements. The final measured stress state of the structure is within the allowable range of the beam and arch composite bridge, and the stress state of the structure is normal and meets the code requirements. The results of load test show that the measured deflection values of the middle section of the main girder of the test hole are all less than the theoretical calculation values, and the deflection is between 1.54~3.40 mm, indicating that the bearing capacity of the structure meets the design requirements. In addition, under the four working conditions, the measured values of the transverse strain of the main girder are all less than the theoretical values, and the values are all positive. The stress at the measured points is in the tensile state, which meets the design requirements, indicating that the structure has a good elastic recovery ability after unloading. This study can provide important reference value for the construction and design of the same kind of under-bearing arch bridge.