Study On Shaking Table Test Of Simulated Earthquake For A New Type Bridge Composed Of An Inclined Arch And A Curved Beam

As a landscape bridge,the composite bridge composed of an inclined arch and a curved beam(BIACB)has prominent spatial effect due to its distinctive shape.The inclined arch undergoes a coupling stress state of axial compression,in-plane and out-of-plane bending moments,and torsion,leading to a complex mechanical behavior.Although it is rare for a bridge to experience a complete damage under seismic excitation,large displacement response and local damage may still occur under strong earthquakes.Moreover,due to the coupling effect of bending moment and torque of the curved beam suspended by the inclined arch,the reaction forces of bearings inside and outside the curved beam are different,causing the bridge to become prone to earthquake disasters,such as bearing failure and the loss of stability.Compared with traditional straight-beam arch bridges,the seismic issue of BIACB is more unpredictable,and thus it is necessary to carry out the research on its seismic performance.This paper focuses on the study of shaking table test of simulated earthquake for BIACB.The main work and conclusions are as follows.(1)According to the similarity principle,a scaled 1:40 experimental model of BIACB was designed and manufactured;The model simulated by artificial mass was used in the present study;According to the principle of equivalence for stiffness,the complex and irregular original section was equivalent to a regular one;In order to accurately simulate the mass distribution of the arch of the prototype bridge,four slotted lead blocks with different sizes were made according to the dimensions of the variable sections of the inclined arch.(2)The seismic excitation test in three directions was carried out.The effects of seismic wave characteristics,input directions and multi-dimensional excitations on the seismic responses of BIACB were intensively studied.The trend of suspender force increment excited by earthquake in different directions was analyzed.(3)Finite element(FE)model of BIACB in shake table test was established by using MIDAS CIVIL software.The finite element model calculation results were compared with the shaking table test results to verify the reliability of finite element method.(4)Based on the prototype bridge design,a set of finite element models of BIACB with different inclination angles of arch were designed and established to investigate the influence of inclination angles of arch on seismic response of BIACB.