交通荷载作用下高填方路堤的工后蠕变模型探析

Creep settlement model of high-filled embankment after construction under traffic loads

针对交通荷载长期作用下高填方路堤的工后蠕变沉降问题,基于车辆交通荷载的特性分析,将路堤填筑体上产生的应力考虑成动静组合应力,建立了填筑体动静组合荷载下的Kelvin体蠕变方程,并将荷载参数对计算模型的影响进行了分析,结果表明:组合荷载下填筑体的蠕变与静载条件下蠕变有相同的时间变化趋势,与相同静载(与组合荷载最大应力相等)作用条件对比,在初阶蠕变段和稳定蠕变段,动蠕变应变都小于静蠕变;荷载频率越大,应变达到周期最大应变所需的时间越短,同时由计算可知荷载频率越小,蠕变长期应变越大;蠕变长期应变是动载幅值系数的一阶线性函数,随着动载幅值系数的增大而增大,且递增速率随加载频率的增大而减小。

Based on the study of the behavior of high fill embankment,the stress in subsidence on high embankment was simplified into combined stress,and the creep settlement model of high-filled embankment after construction was established.By solving the differential equation of the Kelvin model under cyclic load,the creep equation was established,and the influences of the load parameters on the calculation model discussed.The facts show that the creep trend of Kelvin model under cyclic load is the same as that under static load with the changing of time,and the dynamic creep strain is less than the statistic creep strain during the initial section and the stable section in the condition that the statistic loads are equal to the maximum of the dynamic load;that with the decrease of the frequency of cyclic load,the time that the strain reaches the most in the first cycle will increase and the long-term strain will increase too;that the long-term strain which is a linear function of the amplitude parameter of the cyclic load will increase with the amplitude parameter of the cyclic load;and that the increasing speed decreases with the frequency of the cyclic load.