Abstract: The coupling influence of rainfall infiltration and traffic load on the roadbed was analyzed by model test. The stress state and settlement development of low liquid limit silt roadbed under cyclic traffic load and the coupling effect of rainfall infiltration and traffic load were analyzed respectively. The impact of rainfall and traffic load on the bearing performance of roadbed was studied from the macro level. Subsequently, the initial state of the roadbed, the roadbed under the action of cyclic traffic load, the roadbed under the coupling of rainfall infiltration and traffic load were respectively sampled and scanned by the electron microscope scanning experiment. And the causes of the weakening of the roadbed bearing performance were studied from the meso-structure level. The results show that there is no significant change of the bearing performance of the roadbed under the action of the single-circle traffic load of the two-wheel group, but the bearing performance of the roadbed is significantly reduced under the coupling action of rainfall infiltration and traffic load. The dynamic stress on the upper surface of the base layer is reduced by about 17%, and the settlement increases by about 20%.

Key words: highway engineering; roadbed; model test; rainfall infiltration; traffic load; scanning electron microscope

摘要： 采用模型试验分析了降雨入渗及交通荷载耦合作用下对路基的影响，分别分析了低液限粉土路基在循环交通荷载作用下以及在降雨入渗和交通荷载的耦合作用下路基的应力状态及沉降发展情况，从宏观层面研究了降雨及交通荷载对路基的承载性能的影响。随后，通过电镜扫描实验，对初始状态的路基、循环交通荷载作用下的路基、降雨入渗及交通荷载耦合作用下的路基分别取样扫描，从细观结构层面研究了路基承载性能减弱的原因。结果表明：在双轮组单圆交通荷载的作用下路基的承载性能无明显变化，而在降雨入渗及交通荷载的耦合作用下路基的承载性能明显下降，基层上表面的动应力减少约17%，沉降增大20%左右。

关键词: 道路工程；路基；模型试验；降雨入渗；交通荷载；电镜扫描