土工格栅对在役桩承式路堤蠕变的影响

Effect of Geogrid on Creep of Pile-supported Embankment in Service

为了研究土工格栅在黄土地区对在役路堤蠕变变形机制的影响,利用FLAC3D软件及内嵌的FISH语言,对长治至安阳高速公路长平(长治-平顺)路桥过渡段进行一比一数值模拟分析。通过对实测值与模拟值的对比,验证了所建模型的正确性,从而确保了模拟工后蠕变的准确性。通过格栅上部桩土应力比的与格栅下部桩土应力比的比值来分析格栅在工后蠕变中荷载传递的变化机制,通过横向差异变形率来探究格栅对减小因蠕变引起的不均匀沉降的作用。研究表明:格栅、土拱在路堤填筑过程中和工后蠕变间断二者传递荷载的大小处于动态平衡中,虽然填筑过程中,土拱效应远大于张拉膜效应,但随着工后蠕变,张拉膜效应发挥的作用逐渐增大,二者的作用效果差距逐渐缩小,直至达到新的平衡;土工格栅对减小路堤工后蠕变和减小路堤工后不均匀沉降有不可替代的贡献。

In order to study the influence of geogrid in loess area on the creep deformation mechanism of active embankment,FLAC3 D software and embedded FISH language were used to analyze the overcorrection of Changping（Changzhi-Pingshun） road and bridge over Changzhi to Anyang expressway simulation analysis.By comparing the measured value with the simulated value,the correctness of the model is verified,and the accuracy of the postworking creep is ensured.The variation mechanism of the load transfer in the post-working creep is analyzed by the ratio of the pile-soil stress ratio of the upper part of the grid to the pile-soil stress ratio.The transverse deformation rate is used to investigate the effect of the grid on the creep the role of uneven settlement.The results show that the size of the load of the grille and the soil arch in the embankment filling process and the post-working creep intermittent is in the dynamic equilibrium.Although the arching effect is much larger than the tensioning effect in the filling process,the effect of the posterior creep and tensioning membrane is gradually increasing,and the effect gap between the two is gradually reduced until the new balance is reached.The geogrid has a tendency to reduce the postconstruction creep and there is irreplaceable contribution for reducing the uneven settlement of the embankment.