山区2级公路路面早期大面积疲劳破坏状况研究

Research on Large-area Fatigue Damage Conditions of Second Class Highway Pavements at Early Stage in Mountainous Areas

通过对某山区2级公路沥青路面交通量、气象资料、弯沉测定、钻芯试验、路面结构以及排水设施等方面的调查分析,得出该路面出现早期大面积疲劳开裂破坏产生的原因为:超载严重导致基层层底实际拉应力大于设计拉应力而出现疲劳破坏;边沟未设泄水孔、土路肩,致使路基形成封闭水域而导致结构层积水;面层过薄、路面开裂导致雨水下渗并汇聚在面层基层之间产生冲刷破坏;气温骤降导致面层温缩开裂。研究结果将为南方多雨重交通地区的2级公路设计、施工及维护提供一定的参考依据。

Based on investigation and analysis for volume of traffic, meteorological data, deflection measurement, core test, pavement structure and drainage facilities, etc. of asphalt pavement of some second class highway in mountainous area, this paper obtains causes for large-area fatigue cracking damage on this pavement at early stage, including fatigue damage due to actual tensile stress on the bottom of base course which is bigger than designed tensile＇stress caused by serious overload; water logging in structural layer due to enclosed water area on roadbed caused by no drainage openings and earth shoulders equipped for side ditches ; scouring damage produced due to infiltration of rainwater and convergence between surface course and base course caused by too thin surface course and cracking of pavement; and temperature shrinkage crack of surface course due to abrupt decrease of air temperature. The research result of this paper will provide certain reference basis for design, construction and maintenance of second class highways in southern areas with more rain and heavy traffic.