针对城市桥梁采用的独柱墩连续梁桥具有的缺点,提出了采用两跨T形刚构桥梁的结构形式。利用非线性时程分析方法,考虑钢筋混凝土桥墩材料的非线性,对两种桥梁结构在纵向地震动作用下的非线性地震反应行为进行了分析,得到了两种桥梁结构桥墩的弯矩、剪力、位移以及塑性铰转角时程。结果表明,在同一地震动作用下,T形刚构桥墩所受弯矩小于连续梁,所受剪力大于连续梁,桥墩塑性铰的转角远小于连续梁。因此,在同等损伤程度和保证桥墩抗剪能力的情况下,T形刚构比连续梁能够承受更强的地震。
Considering the shortcomings of the continuous girder bridge with single column pier usually used in city, two-span T-shaped rigid-frame bridge with single-column pier is put forward in this paper. Using the time-history analysis and considering the material nonlinearity of reinforced concrete of the pier, the nonlinear seismic responses of the two bridge structures subjected to horizontal seismic ground motion are analyzed, and the time histories of moments, shear forces, displacements and rotation angles of plastic binges are presented. The results show that, compared with the continuous girder bridge, the shear forces of T-shaped rigid-frame bridge are bigger, the mo- ments of T-shaped rigid-frame bridge are smaller, and the angle of plastic hinge of T-shaped rigid-frame bridge is e- ven smalle. So the anti-seismic performance of T-shaped rigid-frame bridge is better than that of continuous girder bridge under the condition that the shear-resistant capacity of pier is remarkable.