考虑动荷载影响的当量轴载换算理论分析

Equivalent standard axle load conversion in theory considering dynamic load

摘要:

为了分析考虑动荷载后的当量轴载,建立二自由度车辆模型,计算出动荷载系数功率谱密度、动荷载的大小及分布概率,推导了考虑动荷载后的当量轴次增长率,并进行实例计算.结果表明:计入动荷载后当量轴次比目前轴载换算标准有不同程度的提高,对沥青路面以设计弯沉值和沥青面层层底拉应力为指标时,高速和一级公路相应指标值提高1%～2%,其他等级公路相应指标值提高2%～5%;以半刚性基层层底拉应力为指标时,高速和一级公路相应指标值提高3%～6%,其他等级公路相应指标值提高7%～17%.对水泥混凝土路面高速和一级公路相应指标值提高15%～25%,其他等级公路相应指标值提高35%～80%.

Abstract:

To consider dynamic load while equivalent standard axle load conversion is carried out,two degree of freedom vehicle model is built to calculate power spectral density of dynamic load coefficient,and then distribution of dynamic load coefficient is calculated.Increasing degree of equivalent standard axles is calculated in theory while dynamic load is considered.The results of examples show that equivalent standard axle load shall be increased when dynamic load is considered for various kind of pavement: for asphalt pavement,while design deflection and tensile stress at the bottom of asphalt pavement is taken as index,1%-2% shall be increased for expressway and first class highway,2%-5% shall be increased for other classes highway;while tensile stress at the bottom of semi-rigid base is taken as checking index,3%-6% shall be increased for expressway and first class highway,7%-17% shall be increased for other classes highway;for cement concrete pavements,15%-25% shall be increased for expressway and first class highway,35%-80% shall be increased for other classes highway.