复杂艰险构造区铁路桥梁系统地震响应分析Part Ⅰ: 断层效应影响

近断层地震对桥梁的影响日益引起关注.本研究提出了桥梁?土?桩基全局建模方法，强调了更详细的桥墩及土壤非线性的真正好处，它可以比一系列轴载更真实地描述物理现象.协同SHAKE91程序并利用p-y曲线、t-z曲线和q-z曲线建立土?桩基非线性模型，采用双线性模型模拟桥墩及桩基础的滞回特性，建立不良地质发育区铁路桥梁?土?桩基多跨简支梁桥体系模型，计算其弹塑性地震响应，分析A_p/v_p等对桥梁的弹塑性地震响应的影响.研究结果表明:桥梁横竖向响应受A_p/v_p影响特点不同，相比墩底固结工况，考虑桩基后桥梁横向地震响应减小；对于竖向响应，在A_p/v_p > 10时桥梁竖向地震响应降低，说明竖向地震在较高频率影响桥梁地震响应. 

Seismic Response of Railway Bridges in Active Complex Tectonic Zones Part Ⅰ: Effects of Fault Effects

There is a growing worry about the impact of near-fault earthquakes on bridges. This paper presents a bridge-soil-pile foundation global modeling technique that stresses the actual advantages of more comprehensive abutment and soil nonlinearity, which may reflect physical events more accurately than a sequence of axial loads. The nonlinear soil-pile foundation model is established using p-y, t-z, and q-z curves and the SHAKE91 program. The bilinear model is employed to simulate the hysteretic characteristics of the pier and pile; the high-speed railway bridge-soil-pile model is established in this paper. The elastic-plastic seismic response of a high-speed railway bridge subjected to the near-fault ground motions and the A_p/v_p ratio on the seismic response of the bridge-pile system is analyzed. The results indicate that the A_p/v_p ratio influences the bridge's lateral and vertical response in different ways. In contrast with the fixed base bridge, the lateral response of the bridge decreases for the bridge-foundation system. On the other hand, for the same bridge-foundation system, the vertical response decreases when A_p/v_p is greater than 10, which demonstrates the vertical NF ground motion impacts the seismic response of the bridge in the high-frequency range.