斜腿夹角对V形墩连续刚构桥地震响应的影响研究

为研究斜腿夹角对V形墩连续刚构桥地震响应的影响及合理斜腿夹角角度，以一座典型V形墩预应力混凝土连续刚构桥为研究对象，采用有限元分析方法研究了斜腿夹角θ对桥梁内力及位移的影响，得出了θ对结构地震响应的影响规律和变化曲线。研究结果表明:随着斜腿夹角的增加，在纵向地震力作用下，墩底纵向弯矩逐渐减小，墩顶和主梁墩顶支撑处纵向弯矩逐渐增大；在横向地震力作用下，跨中横向弯矩逐渐减小，墩底横向弯矩逐渐增大，墩顶横向弯矩基本不变；在竖向地震力作用下，墩底和墩顶竖向弯矩逐渐增大，主梁支撑处竖向弯矩逐渐减小；斜腿夹角对纵向或横向地震力作用下结构位移影响不大，对竖向地震力作用下的位移影响较大。在满足静力设计的前提下，当两斜腿夹角为90°时，结构地震响应相对较小，受力合理性最优。研究成果可为该类桥梁的抗震设计与斜腿夹角角度选取提供参考和依据。

Study on the influence of angle of oblique legs on seismic response of V-shaped pier continuous rigid-frame bridge

In order to study the influence of oblique legs angle on the seismic response of V-shaped pier continuous rigid-frame bridge and obtain the reasonable oblique legs angle, a typical V-shaped pier prestressed concrete continuous rigid-frame bridge was taken as the research object, finite element method was used to investigatethe influence of the angle θ of the oblique legs on the internal force and displacement of the bridge.The influence rule and variation curve of the angle of the oblique legs on the seismic response of the bridge were obtained. The results show that with the increase of the angle of the oblique legs, under the action of the longitudinal seismic load, the longitudinal bending moment of the pier bottom decreases gradually, and the longitudinal bending moment of the pier top and the pier top support of the main beam increases gradually. Under the action of the transverse seismic load, the transverse bending moment of the midspan decreases gradually, the transverse bending moment of the pier bottom increases gradually, and the transverse bending moment of the pier top basically remains unchanged. Under the action of the vertical seismic load, the vertical bending moment of the pier bottom and the pier top gradually increases, and the vertical bending moment of the main beam support decreases gradually. The angle of the oblique legs has little effect on the structural displacement under the action of longitudinal or lateral seismic loads, and has a great influence on the displacement under the action of the vertical seismic loads. On the premise of the satisfying the static calculation, when the angle between the two oblique legs is 90°, the seismic response of the structure is relatively small, and the force reasonableness is optimal. The research results can provide the reference and basis for the seismic design of this type of bridge and selection of angle between oblique legs.