某客运专线T型梁受力性能研究  

Study on the Mechanical Performance of T-shaped Beam of a Passenger Dedicated Line

作　　者：樊少彻 易有淼[2] FAN Shaoche;YI Youmiao(School of Civil Engineering,Southwest Jiaotong University,Chengdu Sichuan 610031,China;China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan Hubei 430063,China)

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《铁道建筑技术》2020年第8期89-93,共5页Railway Construction Technology

摘　　要：为了解某客运专线所采用的新型优化设计T型梁受力性能,对32m预应力混凝土简支T梁进行静载弯曲试验,以分析研究T型梁的变形特征、支座沉降等受力性能,并运用有限元法对试验过程进行模拟。结果表明,两片试验梁的挠跨比均小于设计值,跨中下缘实测应变与荷载基本保持线性关系,梁体拉应力最大区域仍处于弹性工作状态,梁体中部下缘及底面均未发现受力裂缝。有限元模型挠度计算值和实测值误差在I mm之内,变化趋势基本一致;梁体的刚度富余量在13%~27%之间。基于平截面假定和线弹性理论提出适用于客运专线的T型梁应力分布预测方程和挠度预测方程,可快速推算该梁型在荷载作用下某一点的应力和位移。In order to understand the mechanical performance of the T-shaped beam optimized for a passenger dedicated line,the static load bending test of 32 m prestressed concrete simple supported beam is carried out,with a view to analyzing and studying the deformation characteristics of T-shaped beam,bearing settlement and other mechanical properties,and the test is simulated by using the finite element method.The test results show that the deflection span ratio of the two test beams is less than the design value,the measured strain at the lower edge of the middle span keeps linear relationship with the load basically,the area with the largest tensile stress of the beam body is still in the elastic working state,and no stress cracks are found at the lower edge and bottom surface of the middle part of the beam body.The error between the calculated value and the measured value of the finite element model is within I mm,and the variation trend is basically the same.The stiffness margin of the beam is between 13%and 21%.Based on the plane section assumption and linear elasticity theory,the stress distribution prediction equation and deflection prediction equation of T-shaped beam which are suitable for passenger dedicated line are put forward.The stress and displacement of a certain point of the beam under load can be calculated quickly.

关 键 词：客运专线 预应力混凝土T型梁 抗裂弯曲 静载试验 有限元法 

分 类 号：U448.21[建筑科学—桥梁与隧道工程]