Optimization Analysis For Mechanical Properties Of Hinge Joints In Fabricated Hollow Slabs In Highway

With rapid development of economy, a large number of bridges were constructed. Fabricated hollow slab bridge, because of its advantages, such as simple structure, convenient construction, and low cost, etc., has been widely used as the main type of the bridges with small or middle span in China. However, damages of the hinge joint of hollow slabs are severe due to insufficient design, construction, or management, which seriously reduce the overall stiffness of the bridge decks, endanger the safety of bridges and result in over-funding for maintenance. Although some construction measures and reinforcement methods are available, the joint damages are still very common. To solve this problem, this study focused on mechanic behavior of the hinge joints between hollow slabs and concluded that the slab with a width same vehicle lane performs best. Optimal values of parameters related to the new slab section were determined through structural analysis. Contents and conclusions of this thesis are summarized as follow:(1) The previous studies and practices on hollow slabs and hinge joints were reviewed. Typical damage features of hinge joints were identified, and the mechanism of the damages and prevention measures were discussed.(2) Vehicle lanes of hollow slab bridge was arranged according to "Standard atlas of highway bridges and culverts". The influence of relevant position between hinge joints and location of vehicle wheels on shear stress in hinge joints was studied. It can be concluded that the hinge joints would subject to fatigue load of vehicle while they meets the frequent action line of wheel.(3) The relationship between slab width and hinge shear was analyzed by introducing the transverse distribution of wheel tracks and the optimal width of the slab to minimize the stress in the hinge joint was obtained. Based on the modal analysis, the superiority of the optimal width was verified.(4) The model of the hollow slab bridge with optimal width cross section was established using ABAQUS finite element software, and rationality of the optimal width was verified from the aspect of the local stress of the hinge joint. Based on the longitudinal and transverse moving load, the most disadvantageous position of the joint force was determined.. The hollow slab bridge and plastic damage model were established and the effect of hinge joints damage on the stress was analyzed.(5) The influence of span length, skew angle, layer thickness and construction quality of hinge joint concrete on hollow slab hinge joints stress and displacement were studied, and a recommended ranges of the parameters were proposed, for the hollow slab bridge with optimal width cross section.