针对高速公路路基拓宽差异沉降控制问题，本文依托于某实体拓宽工程，建立了拓宽路基有限元分析模型。首先，评价了常规密度填料下的拓宽路基差异沉降，结果表明新老路基的差异沉降量和横坡度均不能满足要求。然后，开展了轻质化泡沫轻质土拓宽路基分析，并基于横坡度和差异沉降控制指标，确定了泡沫轻质土浇筑的最佳湿密度为0.8 g/cm3，最佳弹性模量为470 MPa，以及泡沫轻质土处治拓宽路基时容许高度为6 m。最后，对比分析了泡沫轻质土和常规填土下的路基工后沉降，发现泡沫轻质土可有效降低路基和地基的沉降、水平位移及路基横坡度。
Aiming at the problem of differential settlement control of highway subgrade widening, this paper establishes the finite element analysis model of widening subgrade based on the practical widening project. First, the differential settlement of widening subgrade using conventional density filler is evaluated, and the results show that the differential settlement and cross slope of the new and old subgrades cannot meet the requirements. Then, the widening subgrade of foamed light- weight soil is analyzed, and based on the cross slope and differential settlement control index, the optimal wet density of foamed lightweight soil is 0.8 g/cm3, the optimal elastic modulus is 470 MPa and the allowable height of widening subgrade of foamed lightweight soil is 6 m. Finally, the subgrade post-construction settlements of foamed lightweight soil and conventional filled soil are compared and analyzed. It is found that foamed lightweight soil can effectively reduce the settlement, horizontal displacement and cross slope of subgrade and foundation.
