Test and numerical investigations on the spatial mechanics characteristics of extra-wide concrete self-anchored suspension bridge during construction

摘要

This work is aimed at studying the mechanics characteristics of the self-anchored suspension bridge with extra-wide concrete girder during girder erection and system transformation. First, the determination and implementation processes of reasonable completion state were introduced briefly, taking the Hunan Road Bridge as the background project, which is the widest concrete self-anchored suspension bridge in China currently. Then, the ANSYS beam-type finite element model and field monitoring data were integrated to investigate the cable system evolutions during system transformation. Finally, the global refined finite element model was established using solid element to consider the shear lag effects in extra-wide girder. The measured data show that the cable displacements in tensioned domains were characterized by weak coherence and contraflexure characteristics. The longitudinal and transverse stresses of extra-wide girder distributed unevenly along transverse direction. The maximum shear lag coefficients of girder at completion state reached to 1.3. Moreover, small transverse compressive stress, or even the transverse tensile stress reaching to 1.80?MPa, appeared in the top plate segments. The measures including the arrangement optimization of transverse prestressed tendons and monitoring point redistribution were given. The research can provide references for the structural designing and safety control of the similar bridges.