高海拔山区铁路钢-混凝土结合梁温度场和温度效应研究  

Study on Temperature Field and Temperature Effect of Railway Steel Concrete Composite Beam in High Altitude Mountainous Area

作　　者：魏欣宇 陈克坚[2] 徐昕宇 WEI Xinyu;CHEN Kejian;XU Xinyu(Department of Bridge Engineering,Southwest Jiaotong University,Chengdu 610031,China;China Railway Eryuan Engineering Group Co.,Ltd.,Chengdu 610031,China)

机构地区：[1]西南交通大学桥梁工程系,成都610031 [2]中铁二院工程集团有限责任公司,成都610031

出　　处：《铁道标准设计》2022年第4期103-110,117,共9页Railway Standard Design

基　　金：国家重点研发计划项目(2017YFB1201204-081);中铁二院工程集团有限公司科学技术研究计划项目(KYY2019095(19-21))。

摘　　要：铁路结合梁温度荷载过大会危及列车行驶和桥梁结构安全。为研究高海拔山区高辐射、大温差环境对铁路钢-混凝土结合梁的影响,以典型32 m钢-混凝土结合梁为研究对象,建立有限元模型进行计算分析,得到高海拔山区下铁路钢-混凝土结合梁温度场和温度效应,同时与GB50917—2013《钢-混凝土组合桥梁设计规范》规定的设计温度梯度下的温度效应对比。研究表明,高海拔山区铁路钢-混凝土结合梁日间升降温过程最大温差分别为10.49,10.44℃。大气温差升高16℃,升降温过程混凝土板中部与混凝土下表面、钢梁温差平均增大3,5℃;结合梁升温过程的挠度增大2.45 mm,但降温过程的挠度变化不显著;升降温过程的结合梁混凝土板平均拉应力增大0.56 MPa,钢梁下翼缘最大拉应力变化在1 MPa内;靠近梁端区域栓钉的纵向相对滑移最大平均增量约0.1 mm。采用规范规定的温度梯度进行高海拔山区铁路结合梁设计是可行的,规范结果相比模拟结果,升温过程的挠度小3.27 mm,降温过程挠度大4.56 mm,混凝土内部的拉应力更为不利。Excessive temperature load on railway composite beam will endanger the safety of train running and bridge structure.In order to study the influence of high radiation and large temperature difference environment on railway steel concrete composite beam in high altitude mountainous area,this paper uses a typical 32 m steel concrete composite beam as the research object,establishes a finite element model,carries out calculation and analysis,and obtains the temperature field and temperature effect of railway steel concrete composite beam in high altitude mountainous area.Meanwhile,the temperature effect so obtained is compared with that under the design temperature gradient specified in GB 50917—2013 Code for Design of Steel Concrete Composite Bridges.The results show that the maximum heating and cooling process temperature difference of the steel concrete composite beam in the daytime is 10.49℃and 10.44℃respectively in high altitude mountainous area.When environment temperature difference increases by 16℃,the temperature difference between the middle part of the concrete slab and the lower surface of the concrete and that between the middle part of the concrete slab and the steel beam increases by 3℃and 5℃respectively.The deflection of the composite beam increases by 2.45 mm during the heating process,but it does not change significantly during the cooling process.The average tensile stress in the concrete slab increases by 0.56 MPa and the maximum tensile stress of the lower flange of the steel beam changes within 1 MPa.The longitudinal relative slip of the stud near the beam end increases by 0.1 mm.It is feasible to use the temperature gradient specified in the code to design railway composite beams in high altitude mountainous areas.Compared with the simulation results,the deflection of the code result is 3.27 mm smaller in the heating process and 4.56 mm larger in the cooling process,and the tensile stress of concrete is more unfavorable.

关 键 词：大温差 山区铁路 铁路桥 钢-混凝土结合梁 温度场 温度效应 

分 类 号：U448.13[建筑科学—桥梁与隧道工程] U441[交通运输工程—道路与铁道工程]