轨道约束对近断层简支梁桥纵向地震响应影响  

Influence of Track Constraints on Longitudinal Seismic Response of Near-fault Simply Supported Beam Bridge

作　　者：李天铭 LI Tianming(Science and Innovation Industrial Development Co.,Ltd of China Railway First Group Co.,Ltd.,Xi’an 721000,China)

机构地区：[1]中铁一局集团科创产业发展有限公司,西安721000

出　　处：《高速铁路技术》2025年第2期62-69,共8页High Speed Railway Technology

摘　　要：随着我国铁路路网规模的不断扩展,高速铁路在近断层地区架设桥梁已成为不可避免的趋势。本文以一座近断层铁路简支梁桥为研究对象,通过有限元分析软件Opensees对该桥梁进行精细化建模,重点研究了扣件纵向阻力、滑动层摩擦系数以及剪力齿槽刚度等因素对铁路简支梁桥在地震作用下响应的影响。研究结果表明,随扣件纵向阻力增大,墩底剪力呈现增大趋势,墩底弯矩则呈现减小趋势,且中墩地震响应大于边墩;随滑动层摩擦系数增大,桥梁地震响应呈现减小趋势,且对边墩的影响较中墩更为显著;随剪力齿槽刚度的增大,桥梁地震响应呈现先增大后趋于稳定;在不同轨道约束作用的影响下,近断层脉冲地震动会显著增加主梁的纵向位移和墩底内力,但并未明显改变地震响应的总体规律。With the continuous expansion of China’s railway network,it is inevitable to build high-speed railway bridges in near-fault areas.This paper took a near-fault railway simply supported beam bridge as the research object,and employed the finite element analysis software Opensees to finely model the bridge.The study focused on the impact of such factors as the longitudinal resistance of fasteners,friction coefficient of sliding layer and shear alveolar stiffness on seismic response of railway simply supported beam bridge.The results show that with the increase of the longitudinal resistance of the fastener,the shear force at the pier bottom tends to increase,while the bending moment at the pier bottom tends to decrease.Additionally the seismic response of the middle pier is greater than that of the side pier.With the increase of the friction coefficient of the sliding layer,the seismic response of the bridge tends to decrease,with a more significant impact on the side pier compared to the middle pier.With the increase in the stiffness of shear alveolar,the seismic response of the bridge increases first and then stabilizes.Under the influence of different track constraints,near-fault pulse ground motion has a significant amplification on the longitudinal displacement of the main beam and the internal force of the pier bottom,but it does not significantly change the seismic response law.

关 键 词：轨道约束 近断层 脉冲地震动 纵向地震响应 

分 类 号：U448.217[建筑科学—桥梁与隧道工程]