Mechanical Properties Of Lower Structure Of Curved Girder Bridge With Steep Transverse Slope Research On Seismic Performance Evaluation

In order to meet the needs of route design and crossing terrain,the steep cross-slope curved beam bridge is widely used in the construction of bridges in the western mountainous areas.This paper combines the specific engineering practice and found that the double-column pier has the characteristics of strong adaptability to complex terrain conditions,convenient construction and low cost.In addition,in view of the characteristics of different types of slopes such as micro-slopes,gentle slopes,steep slopes and extremely steep slopes in the western mountainous areas,as well as the requirements of seismic fortification targets of engineering bridges,this paper mainly carried out the following aspects:(1)The development status and structural characteristics of the curved girder bridge are introduced.The development of the four aspects of the mechanical behavior of the curved girder bridge,the lower structure of the steep cross-slope bridge,the pile-soil interaction and the performance-based seismic design are summarized.And the research status,the problems existing in the current steep cross-slope bridge research are summarized.(2)Considering the influence of curvature,under the vertical load,the curved beam bridge will generate corresponding torque while being subjected to bending,and the torque will in turn cause flexural deformation,that is,the "bending and torsion coupling" effect.In this paper,the factors affecting the "bending and torsion coupling" effect of curved girder bridges are analyzed.The basic assumptions and modeling points of the girder modeling of curved girder bridges are described.The distribution of curvature radius to pier top load distribution under different load conditions is analyzed.influences.(3)Analyzed the interaction mechanism between pile and soil when the pile foundation of the steep cross-slope bridge was subjected to the load transmitted from the superstructure.Based on ABAQUS software,the constitutive model of rock and soil and the simulation method of pile-soil contact relationship were studied.The change of the distance between the top of the pile and the lateral slope of the steep cross-slope curved girder bridge under the load combined with the top of the pier,the slope of the slope and the bearing behavior and mechanical behavior of the pile foundation under the height and pier diameter of the double-column pier Impact.(4)Taking the ground motion peak acceleration PGA as the strength index and the pier top displacement ductility ratio as the damage index,the direct regression probability demand model is used to establish the theoretical vulnerability curve of the steep cross-slope terrain double-column pier by the deterministic analysis method.The influence of the double-column pier height change,the cross-beam setting and the cross-slope change on the seismic performance is analyzed.