敦格铁路沙山沟特大桥风荷载计算方法

Wind Load Calculation of Shashangou Bridge on Dunhuang-Golmud Railway

以位于库姆塔格沙漠东缘的敦格铁路沙山沟特大桥为研究对象,对比分析了TB 10002—2017《铁路桥涵设计规范》与JTG/T D603360⁃01—2018《公路桥梁抗风设计规范》中关于风荷载计算的规定;采用风速廓线仪在桥址处实测风场数据,测量出下垫面粗糙度Z0为0.093 cm;收集桥址附近气象站连续21年的风速观测数据,通过统计年平均最大风速并采用皮尔逊Ⅲ型曲线推算出百年一遇最大风速为24.8 m/s。研究结果表明,Z0现场实测值与规范规定值相差较大,对于特殊地区的重点桥梁,应该根据现场实测数据计算风荷载。

Taking the Shashangou bridge on the east edge of Kumtag desert as the research object,the wind load calculation provisions in TB 10002—2017“Code for Ddesign on Railway Bridge and Culvert”and JTG/T D603360-01—2018“Wind-resistant Design Specification for Hghway Bridges”were compared and analyzed.The wind field data measured by wind profiler at the bridge site show that the roughness Z0 of underlying surface is 0.093.The wind speed observation data of the weather station near the bridge site for 21 consecutive years were collected,and the PearsonⅢ-type curve was used to calculate the maximum wind speed with 100 year return period as 24.8 m/s.The research results show that there is a big difference between the measured value of Z0 and the value specified in the code.For the key bridges in special areas,the wind load should be calculated according to the field measured data.