【摘要】 为了研究路堤在地震作用下的易损性特点和挡土墙对路堤震害易损性的影响,选取连云港—霍尔果斯高速公路西安—宝鸡段K1125+470处路堤进行理论性震害易损性评价。通过划分路堤震害等级,选取路堤震害损伤参数,建立了路堤震害等级与路堤震害损伤参数之间的对应关系;采用Flac软件建立了无挡土墙和有挡土墙路堤的有限差分模型,选取实际记录地震动进行了增量动力分析,明确了一定地震动峰值加速度作用下无挡土墙和有挡土墙路堤震害损伤参数的取值规律;采用概率性地震需求分析方法研究了路堤发生各等级震害的概率,绘制了路堤震害易损性曲线,并将无挡土墙和有挡土墙路堤的震害易损性评价结果进行对比。研究结果表明:地震动峰值加速度为1.2g时,无挡土墙和有挡土墙路堤发生毁坏的概率比地震动峰值加速度为1.0g时平均高16.854%和76.679%,比地震动峰值加速度为0.8g时平均高95.895%和88.008%,即无论有无挡土墙,地震动峰值加速度越大,路堤发生更严重等级震害的概率越大;超越概率为30%、50%和80%时,有挡土墙路堤发生毁坏时对应的地震动峰值加速度比无挡土墙路堤平均高17.93%、18.14%和18.34%,即在相同地震作用下,有挡土墙路堤的震害状况低于无挡土墙路堤,说明挡土墙对提高路堤抗震性能具有积极作用。更多还原

【Abstract】 In order to reveal the characteristics of embankment fragility under seismic actions and investigate the influence of retaining walls on embankment seismic fragility,seismic fragility was theoretically evaluated in view of the K1125+470 embankment of Xi’an-Baoji segment in Lianyungang-Huoerguosi expressway.Embankment seismic fragilities were ranked and seismic damage parameters were selected.The corresponding relationship between embankment seismic damage levels and seismic damage parameters as well as the finite-difference models of embankments with and without a retaining wall based on Flac was established.The actual seismicoscillation records were selected for the Incremental Dynamic Analysis,clarifying regularity of seismic damage parameters under the effect of peak ground acceleration with and without a retaining wall.Probability of seismic damage at different grades was investigated on the basis of probabilistic seismic demand analysis and the seismic fragility curves were also mapped.The comparison was made for the seismic fragility assessment results of the embankments with and without a retaining wall.The results show that when peak ground acceleration reaches 1.2g,the probabilities of destruction to the embankments with and without a retaining wall are 16.854%and 76.679% higher than the probability with the peak ground acceleration of 1.0g on average,95.895% and 88.008% higher than the probability with the peak ground acceleration of 0.8g on average.Whether the retaining wall exists or not,the greater the peak ground acceleration is,the greater the probabilities of severe embankment seismic damage are.When the transcendental probabilities of destruction damage are 30%,50% and 80% respectively, ground peak accelerations corresponding to destruction of embankment with a retaining wall are 17.93%,18.14% and 18.34%respectively higher than those without a retaining wall,namely,under the same seismic actions,the seismic damage status of embankment without a retaining wall is more serious than that with a retaining one,with a positive effect of a retaining wall on embankment seismic performance.更多还原