车辆荷载和车道荷载对桥梁结构可靠度的影响

公路桥梁结构的整体计算采用车道荷载,结构的局部计算采用车辆荷载,车辆荷载与车道荷载的作用不得叠加.将采用这2种荷载设计的结构进行可靠度对比,结果表明,按车辆荷载设计的结构满足正常使用功能的可靠度偏低,更容易发生损坏,这些损坏会影响到结构的正常使用.提出通过调整重型车辆通过桥梁时的交通行驶规则,增大结构按正常使用极限状态设计时车辆荷载的代表值,从而提高按车辆荷载设计的结构可靠度.

Influences of Loads on Vehicles and Lanes on Reliability of Bridge Structures

Integral calculation for highway bridge structures adopts loads on lanes,local calculation for structures employs loads on vehicles,and the effects of loads on vehicles and lanes should not be superimposed.This paper compares reliabilities of structures designed by means of these two loads,the result show that the reliability of structures designed based on loads on vehicles to satisfy normal functions of use is lower and easier to damages,which will affect normal use of structures.The paper proposes to increase effect values of actions of loads on vehicles during design in limit state of normal use by adjusting traffic driving rules as heavy vehicles pass bridges so as to improve reliability of structures designed on the basis of loads on vehicles.