Monitoring and Analysis of the Construction Process of Prefabricated Assembly Pier of High-Speed Railway
The construction process monitoring should be carried out to evaluate the influence of assembly construction process on the integrity and health status of prefabricated bridges.The whole construction process monitoring of prefabricated assembly socket pier refers to arranging steel bar strain gauges,concrete strain gauges and vibrating string strain gauges in advance at the key position to monitor the connection nodes of bridge substructure(foundation-bridge pier,bridge pier-pier cap)during the construction process.The monitoring points contain the strain of concrete and stress of steel located in the connections of bridge substructure(foundation-bridge pier,bridge pier-pier cap)and cap during the construction process of PC cap and the transportation and construction of box girder.Because the deviation caused by construction load conditions is cumulative,the health status of the bridge during construction can be evaluated by monitoring.The monitoring and analysis,including the data of vibrating string strain gauge and concrete surface strain gauge show that during the construction of PC cap,the maximum compression strains of the concrete inside and outside the foundation-bridge pier connection zone are 181 με and 48 μεrespectively.Meanwhile,the maximum tension strains of the concrete inside and outside the foundation-bridge pier connection zone are 146 με and 44 με respectively,and the maximum stress of reinforcing bars there is 44.5 MPa.During the transportation and construction of PC box girder,the maximum compression and tension strains of the concrete at the bridge pier-pier cap connection zone are-118 με and 148 με respectively,and the maximum stress of reinforcing bars there is 70.8 MPa.The results of construction monitoring show that the stress and strain of the connections of the bridge substructure are small during the construction process of PC cap and the transportation and construction of box girder,and the steel bars and concrete are in the elastic stage.The construction load incurs little damage to the overall performance of the structure and is within the safe range.
万方数据
