Research On Anti-collision Performance Of Steel Barrier Installed On Long-span Bridge

With the rapid development of ship transportation industry and the construction of cross-sea bridges in China,vessel-bridge collisions frequently occur,which leads to huge loss of people’s life and property.Therefore,it is essential to research the vessel-bridge collision problem.In this paper,the finite element method is used to analyze the vessel-bridge collision by talking the engineering project of the Quanzhou Bay Bridge as study case.This research work is also focused on vessel-bridge collision considering the pile-soil interaction,and the anti-collision performance and structural optimization of anti-collision steel barrier.The main research works are as follows:Firstly,the research background and significance to research the vessel-bridge collision are briefly introduced.The current research status of vessel-bridge collision in domestic and abroad is summarized.Moreover,the empirical formulas and related regulations on vessel-bridge collision,and the research method to solve vessel-bridge collision problem are elaborated.The finite element software of ANSYS/LS-DYNA is used to simulate the 1900T barge colliding on square piers and rigid wall with different sizes,and calculation models are validated by comparing the references.After that,the barge with different velocities colliding on the bridge cap estabilished by the nonlinear damage concrete model is simulated.The calculation results show that the collision force,and horizontal displacement of the cap and piles don’t increase monotonously with the increase of the barge’s velocity.The concrete cracking area is most likely to appear at the top of the group piles and fixed bottom of the group piles.Compared with the results of linear elastic cap,the collision force and horizontal displacement of the model with nonlinear inelastic damage concrete are smaller.By simulating the barge-bridge collision with the anti-collision steel barrier,it can be found clearly that the steel barrier can improve the anti-collision capability of the bridge cap effectively,and the most vulnerable damage positions of the steel barrier are at the top and bottom of the steel barrier’ corner.After installing the steel barrier on cap,the 1st,2nd and 3rd residual principal tensile stress of group piles decreases by 33.33%,56.67%and 45.21%compared to the ones without steel barrier.After considering the pile-soil interaction and the steel barrrier,the 1st,2nd and 3rd residual principal tensile stress increases by 0.50,2.75 and 2.87 times respectively compared with the ones without pile-soil interaction.After considering the initial stress of the soil and structure and the steel barrier is installed on cap,the 1st,2nd and 3rd residual principal tensile stress of the group piles increases by 32.98%,17.33%and 34.48%respectively.In addition,the influence factors such as boundary conditions of soil and group piles,the structure style of pile foundation,the initial stress of sub-soil and structure induced by gravity on barge-bridge collision are evaluated.The necessity to consider the most complex conditions,the energy consumption of the steel barrier under study cases,the residual stress of the structure after collision,and most vulnerable damage area on structure are analyzed.Finally,the classification,characteristics,applicable conditions of anti-collision system are summarized.By simulating the barge collision on the cap considering anti-collision steel barrier with different types,thicknesses and spaces of steel plates,and the residual stress of the cap after collision and the materials consumption of steel barrier under different conditions are compared to take the structural optimization.The anti-collision steel barrier composed of the steel plates type of Q390,thickness of 8.00 mm and spacing of 0.80 m is the optimized structure.