About the author:

The 9th Engineering Co., Ltd., MBEC, Zhongshan, Guangdong 528400, China

Abstract:

The reconstruction and expansion section of Xingang Road Bridge on the Changchun⁃ShenzhenExpressway is located in a transition curve segment, where deck elevation and transverse gradientadjustment are complex, and conventional synchronous jacking can not satisfy the control requirementsarising from the nonlinear distribution of jacking heights at different support points under varyingsuperelevation conditions. In view of these engineering characteristics, an intelligent constructiontechnology for proportional asynchronous jacking of existing continuous girder bridges was proposed. Byoptimizing the rotation axis and jack layout, the jacking control values at each support point weredetermined, and a PLC⁃based intelligent control system was adopted to realize deck elevation adjustment.In addition, self⁃weight⁃based preloading, stepwise transition of the bearing system under restrictedworking space, and real⁃time monitoring throughout the construction process were integrated to ensure thesafety and precise control of gradient adjustment. Field application showed that the transverse gradient ofthe existing bridge was adjusted from 1.7% to -0. 3%, with the maximum jacking height of 15.1cm. Thejacking and lowering processes remained stable, the deck elevation and longitudinal / transverse gradientssatisfied the design requirements, and both the construction duration and project cost were reduced.