摘要
随着我国货运铁路重载扩能运输的发展,大轴重、长编组引起的噪声污染日趋严重,后装声屏障已成为减小噪声污染的主要措施之一,但通过扩能改造提升的在役重载铁路桥梁原设计时并未考虑后装声屏障对桥梁结构的影响。为研究在重载铁路桥梁上后装声屏障的适应性,以在役铁路桥梁主梁型32 m简支T梁(专桥-2059A)为研究对象,采用数值模拟与结合现场实测桥梁现状分析的方法,基于不同荷载组合作用,开展T梁加装声屏障后主梁、声屏障与桥梁连接的位置及道砟槽板适应性分析,并对T梁翼缘板及声屏障结构的潜在薄弱位置进行破坏分析。研究结果表明:T梁加装声屏障后,主梁纵向强度受梁体L/8~L/4处抗剪控制,其中梁体L/8处抗剪安全系数为1.70,小于规范要求值1.80;声屏障与桥梁连接位置安全储备不足,其中,在最不利荷载组合作用下,挡砟墙钢筋应力超过容许值1.25倍、裂缝宽度超过容许值0.54 mm;道砟槽板在最不利荷载组合作用下,其钢筋应力安全储备剩余23.2%、裂缝宽度比规范容许值小0.07 mm。综合考虑3种分析,该类型T梁不宜后装声屏障;在最不利情况下,T梁及声屏障结构破坏顺序依次为预埋化学锚栓处、挡砟墙处、声屏障立柱与水平杆交接处、道砟槽板变高度处、翼缘板根部处。
With the development of heavy-haul capacity expansion transportation of freight railways in China,noise pollution caused by large axle load and long marshalling tends to be increasingly serious and the rear noise barrier has become one of the main measures to reduce noise pollution.However,the original design of the in-service heavy haul railway bridge upgraded through capacity expansion does not consider the influence of the rear noise barrier on the bridge structure.The 32 m simplysupported T-beam(bridge-2059A)of existing railway bridge is studied.The method of numerical simulation combined with field measurement of bridge status analysis is adopted.Based on different load combinations,the adaptability analysis of the main girder,the position of the noise barrier and the bridge connection and the ballast tank after the T-beam is installed with the noise barrier is carried out,and the potential weak position of the flange plate and the noise barrier structure is analyzed.The results show that after the T beam is equipped with the noise barrier,the longitudinal strength of the main girder is controlled by the shear resistance at L/8~L/4 of the beam body,and the shear safety factor at L/8 of the beam body is 1.70,which is less than the standard value(1.80).The safety reserve of the connection between the noise barrier and the bridge is insufficient.Under the most unfavorable load combination,the reinforcement stress of the ballast retaining wall exceeds the allowable value by 1.25 times,and the crack width exceeds the allowable value by 0.54 mm.Under the most unfavorable load combination,the residual safety reserve of reinforcement stress is 23.2%,and the crack width is 0.07 mm smaller than the allowable value.Considering the three kinds of analysis,it is concluded that this type of T-beam should not be equipped with noise barrier.In the most unfavorable situation,the damage order of T-beam will be:embedded chemical anchor,ballast retaining wall,the junction of noise barrier column and horizontal bar,the height of ballast tank,and the root of flange plate.
作者
郑晓光
刘永前
陈树礼
李勇
许宏伟
ZHENG Xiaoguang;LIU Yongqian;CHEN Shuli;LI Yong;XU Hongwei(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;School of Safety Engineering and Emergency Management,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《铁道标准设计》
北大核心
2024年第3期123-132,共10页
Railway Standard Design
基金
河北省重点研发计划项目(20375410D,21375403D)
河北省自然科学基金项目(E2020210017)
石家庄铁道大学优秀青年科学基金项目(2018019)。
关键词
重载铁路
铁路桥梁
预应力混凝土
T梁
声屏障
实测修正
数值模拟
适应性
heavy haul railway
railroad bridge
prestressed concrete
T-beam
noise barrier
measurements correction
numerical simulation
adaptability
