Abstract: Aiming at the problem of gravity shoulder retaining wall setting under widening and rebuilding roadbed of mountainous highway, the analysis model was established by field test and numerical simulation, combining with G307 reconstruction and extension project. The stress and deformation characteristics of subgrade and retaining wall were studied. The reliability of the numerical analysis results was verified by comparing the numerical simulation results with the field measured values. At the same time, the related design and construction parameters were analyzed. The results show that the stability of the fill subgrade decreases with the widening width within a certain width limit; the stability of roadbed and retaining wall can be greatly improved by reasonably controlling the compaction degree and the selection of filling materials; the working performance of the roadbed and retaining wall can be improved by controlling the excavation of the soil mass of the old roadbed slope; the horizontal displacement of the wall body can be reduced by replacing the foundation with a certain depth.

Key words: highway engineering, mountain road, subgrade widening, retaining wall, numerical simulation

摘要： 针对山区公路路基加宽改建中的重力式路肩挡土墙问题，笔者结合G307改扩建工程，通过现场试验，并采用数值模拟方法建立分析模型，对路基和挡土墙的受力与变形特性进行研究，将数值模拟结果与现场实测值进行对比，验证了数值分析结果的可靠性，同时对相关设计及施工参数进行影响性分析。结果表明：在一定宽度限制内，填方路基的稳定性随着加宽宽度的增加而降低；合理控制压实度及填料的选择可以较大幅度的提高路基及挡土墙的稳定性；控制老路基边坡土体的开挖，可以改善路基和挡土墙的工作性能；对地基进行一定深度的换填处理，可以减小墙身水平位移量。

关键词: 道路工程, 山区公路, 加宽路基, 挡土墙, 数值模拟