公路波形钢腹板PC简支箱梁桥冲击系数的计算分析

Calculation and Analysis of Impact Factors of Highway Simply-Supported PC Box Girder Bridge with Corrugated Steel Webs

为科学计算和合理评估公路波形钢腹板PC简支箱梁桥在移动车辆荷载作用下的冲击系数,以一座计算跨径为30m的单箱单室波形钢腹板PC简支箱梁桥为研究对象,运用MATLAB软件编写了车桥耦合振动的计算程序。运用所编制的程序计算分析了车辆类型、行车速度及路面平整度等因素对波形钢腹板PC简支箱梁桥冲击系数的影响,并将计算所得的冲击系数与《公路桥涵设计通用规范》(JTG D60-2015)规范值进行对比。结果表明:波形钢腹板PC简支箱梁桥的冲击系数应依据路面平整度的情况合理确定;冲击系数并不一定随车重的增加而增大,可能与车型有关;车重和车速对冲击系数的影响较为复杂,无明显规律;总体的超规范工况数和相应的最大超规范百分比与车辆类型有关。

To scientifically calculate and reasonably evaluate the impact factors of the highway simply-supported prestressed concrete（PC）box girder bridge with corrugated steel webs subjected to the moving vehicle load,a simply-supported PC single-cell single-box girder bridge with corrugated steel webs and with calculated span length of 30 m was taken as the study object and the calculation program for the vehicle and bridge interaction vibration was compiled,using the software MATLAB.The complied program was then used to calculate and analyze the influences of the vehicle types,vehicle travelling speed and road surface roughness on the impact factors of the bridge and the impact factors obtained from the calculation were compared to the corresponding values in the General Code for Design of Highway Bridges and Culverts（JTG D60-2015）.The results demonstrate that the impact factors of the simply-supported PC box girder bridge with corrugated steel webs should be reasonably determined according to the road surface roughness.The impact factors do not necessarily increase with the increase of the vehicle weight,but the increase of the impact factors is probably related to the vehicle types.The influences of the vehicle weight and vehicle traveling speed on the impact factors are complex and not regular and the general numbers exceeding the load cases and the corresponding maximum percentage exceeding the provisions in the code are related to the vehicle types.