摘要
为了探讨小半径曲线连续刚构桥梁在抗震计算中采用直梁代替弯梁的简化计算,以一座(80+2×120+80)m的小半径连续刚构桥为例,比较了0°、15°、30°、45°、60°、75°、90°七种水平地震输入方向地震荷载工况下的直梁、弯梁模型的动力特性和地震响应。计算结果表明,在任意水平方向输入地震动时,构件的地震响应最大值均可能出现,因此可通过改变地震动输入方向来确定地震响应最大值;该曲线桥可以按照直线桥进行抗震设计,但需保证最不利截面的设计强度、提高墩顶梁截面的抗剪强度、加强梁端外侧支座的抗震设计强度并约束主梁的横向位移。在满足上述局部构造设计强度的有效条件下,采用直梁代替弯梁对该桥进行简化抗震设计的方法适用可行。
Focused on the the simplified calculation for the straight beam instead of the curved beam in the seismic calculation of curved continuous rigid frame bridge with small radius, this paper takes a small radius curved rigid frame bridge which has a span of （80 ＋2 x 120 ＋ 80） m as the example. The dynamic characteristics and seismic response of straight beam model and curved beam model under seven seismic load conditions are compared by adjusting the horizontal seismic input direction as 0 0, 15 °, 30 °, 45 °, 60 °, 75 °, 90 °. According to the seismic response calculation, the maximum seismic response of component can be emerged under ground motion input of random direction. Thus, it is a feasible method to determine the maximum seismic response of component by changing the input direction of ground motion. This curved beam model can be designed by straight beam model in seismic design, but the aspects including the design strength for the most favorable sections, shear strength for the beam sections on the top of piers, strengthening seismic design intensity of the lateral bearings in beam ends and constraining the lateral displacement of the main beam must be ensured. The simplified seismic design method of calculating the straight beam instead of the curved beam is applicable and feasible under the condition of satisfying the local structure design strength from the above - mentioned.
出处
《北方交通》
2017年第12期1-5,9,共6页
Northern Communications
关键词
曲线连续刚构桥
地震响应
动力特性
简化抗震计算
Continuous curved rigid frame bridge
Seismic response
Dynamic characteristics
Simplified seismic analysis
