通过室内模型试验，研究了新旧路基差异沉降作用下土工格栅加筋拓宽路堤填土的工作性状; 试验共设计了在加筋拓宽路堤填土中不铺设土工格栅、铺设2 层土工格栅，新填路基发生0、20、30、50mm 差异沉降等6 种工况，测试和分析了荷载作用下各工况路堤的不均匀沉降分布和土工格栅的变形特性．结果表明: 在加筋拓宽路堤填土顶层和底层加铺土工格栅，可以有效减少堤顶荷载作用下的路堤填土沉降变形; 相同路基差异沉降条件下，相比未加筋路堤，加铺2 层土工格栅加筋路堤的荷载作用位置附近发生的沉降最大可以减少48%; 在路基差异沉降作用下，新旧路堤结合处的土工格栅受力最大，土工格栅可以较好地均化路堤顶面沉降分布，调节沿路堤横断面方向新旧路堤结合处的差异沉降．

In order to investigate the performance of the reinforced widening embankment with geogrid under the differential settlement between the new widening subgrade and the old one,some indoor model tests were repectively designed and conducted under six conditions,including the no-geogrid and 2-layer geogrid reinforced widening embankments as well as the differential settlements of 0,20,30 and 50mm. For each condition,both the differential settlement distribution of the embankments and the strain performance of geogrid were tested and analyzed under load. The results show that placing the geogrid on the top and bottom layers of the reinforced widening embankment can effectively reduce the settlement deformation of the embankment caused by the load at the top of the embankment,that,as compared with the no-geogrid reinforced embankment,the settlement of the 2-layer one can reduce by at most 48% near the place under load at the same amount of the subgrade differential settlement,that the geogrid at the junction of the old embankment and the new widening one receives the biggest tension stress under the subgrade differential settlement,and that the geogrid can significantly homogenize the settlement distribution on the embankment surface and adjust the differential settlement of the junction in the cross-section direction of the embankment.