Static And Dynamic Calculation Analysis Of Metro Station-viaduct Combined Structure

With the rapid development of cities,the co-location structure of stations and bridges has emerged as the times require,and it is becoming more and more common.In order to study the static and dynamic characteristics of a co-constructed structure of a corrugated steel web-steel composite box girder bridge and a four-line transfer subway station,this paper uses Midas / Civil software to establish a finite element model based on relevant design data.Based on the bridge code and building code,the static response of the structure under 6 types of sub-loads and 8 load combinations was analyzed.At the same time,the multi-Ritz vector method is used to analyze and compare the natural vibration characteristics of the joint structure and the separately constructed corrugated steel web steel-concrete composite bridge.The results show that:(1)In addition to the dead load,The effect of bridge lane load on the vertical displacement of bridge structure,civil defense load on the vertical displacement of subway station structure,the effect of temperature on the stress of concrete bridge deck,the effect of bridge lane live load on the shear stress of corrugated steel web,the normal stress of steel bottom plate and civil defense load on the vertical and horizontal beam of the top floor and structural column are the most significant.The partial load acting on a bridge or a subway station alone has very little effect on the displacement and stress of another part of the structure.(2)Under each load combination condition,the stress results of the longitudinal and transverse beams are generated by accidental combination,and the stress peaks of other parts are generated under basic combination conditions.And generally speaking,for the stress results of each part of the composite structure,the reference building code is more conservative(the stress peak value is larger)when the basic combination is used,and the reference bridge code is more conservative(the stress peak value is larger)when the occasional combination is used.(3)The fundamental frequency of the joint structure is 1.067 Hz,and the fundamental period is 0.938 s.Its first-order mode is manifested by the negative vertical drift of the double bridge above the X axis.Due to the relatively small stiffness of the column pier,the fixed pier will have Large amplitude vertical swing,meanwhile,two bridges produce positive and symmetrical vertical bending in the same direction.(4)The stiffness of the upper composite bridge is less than that of the subway station below.The lateral stiffness of the composite bridge is greater than the vertical and longitudinal stiffness.The vertical stiffness of the station structure is greater than that of the transverse and longitudinal bridges.(5)The joint construction with the subway station will reduce the stiffness of the combined bridge structure compared with the single construction,and the most obvious reduction direction is the longitudinal stiffness extending in the positive direction of the X axis,and the frequency of its related mode shapes The reduction was 12.7%.And because the reduction of the lateral stiffness is larger than the lateral stiffness,the forward longitudinal flutter mode appears earlier.