预应力混凝土简支梁桥在重载作用下的抗剪性能分析  

Analysis on Shear Performance of Prestressed Concrete Simply Supported Beam Bridge under Heavy Load

作　　者：战昂[1] 欧阳平 ZHAN Ang;OUYANG Ping(CCCC First Highway Consultants Co.Ltd.,Xi'an 710075,China)

机构地区：[1]中交第一公路勘察设计研究院有限公司,西安市710075

出　　处：《公路》2021年第11期90-95,共6页Highway

基　　金：国家自然基金项目,项目编号51308396。

摘　　要：以某跨度为32m的变截面预应力混凝土简支T梁为研究对象,通过建立数值模型,重点分析了恒载、活载以及不同重载列车荷载组合作用下的梁体剪应力变化规律。分析得到了以下结论:预应力荷载对梁体剪应力影响最大,其次是自重荷载,最小的是二期恒载,剪应力峰值均发生在距离梁端支座1.5m处,恒载组合作用下梁体剪应力满足规范要求;C64型、C70型、C80型和KM98型列车荷载下剪力以及弯矩依次增大,简支梁桥结构的安全性能逐渐降低;不同荷载组合下的剪应力分布曲线变化规律相同,并且剪应力峰值均满足规范要求;工程中可以用剪应力作为控制梁体裂缝开展的主要因素,以初步防止开裂现象发生。Taking a 32 mspan PC simply supported T-beam as the research object,a numerical model is established by using the finite element software MIDAS/civil.The shear stress variation law of the beam body under the action of dead load,live load and different heavy load train load combinations are analyzed emphatically.The following conclusions are obtained:the prestressed load has the greatest influence on the shear stress of the beam,followed by the self weight load,and the minimum is the second stage.The results show that the peak value of shear stress occurs at 1.5 maway from the beam end bearing,and the shear stress meets the requirements of the code under the combined action of dead load;the shear force and bending moment of C64,C70,C80 and KM98 train load increase in turn,and the safety reserve of bridge structure gradually decreases;the variation law of shear stress distribution curve under different load combinations is the same,and the maximum shear stress meets the requirements of the code.In projects practice,shear stress can be used as the main factor to control the development of beam cracks,which can be used to prevent the occurrence of cracks.

关 键 词：简支梁 重载列车 预应力 剪应力 数值模拟 性能分析 

分 类 号：U441.5[建筑科学—桥梁与隧道工程]