路面实体结构模型力学响应试验方法研究

Study on Mechanical Response Test Method for Real Pavement Structure Model

为获得荷载作用下路面结构的实际力学响应规律,设计并完成了路面实体结构模型试验,讨论了试验方法的平行性和复现性,分析了3种典型路面结构模型的力学响应规律。结果发现:路面结构模型力学响应试验方法平行性、复现性、可靠性较好,可作为路面结构力学响应行为研究的一种有效手段;当试验条件相同时,不同路面材料的结构模型受力情况存在显著差别,水泥稳定碎石和沥青混凝土表面径向应变随着与荷载距离的增加呈现压缩-拉伸交替变化、具有明显的力学响应特征点,而水泥混凝土并无此现象;近荷载端沥青路面结构处于受压区,而稍远离荷载的位置则为受拉区,当荷载较重时,可能会引起沥青路面表面开裂,形成荷载型Top-down裂缝;路面结构模型力学响应试验可以反映路面材料在结构中的实际工作状态,能够为路面结构计算和材料参数确定提供参考。

In order to obtain authentic mechanical response rule of pavement structure under loading, the corresponding experiment is designed and accomplished. The parallelism and reproducibility of the experiment are discussed, analysis and the mechanical response rules of typical pavement structure models are discussed. It is found that （1） The mechanical response test method for pavement structure has the characters of good parallelism, reproducibility and reliability, it can be used as an effect way to investigate the mechanical response behaviors of pavement structures. （2） The mechanical states of different pavement materials are quite different under the same test condition. For the pavement of cement stabilized macadam and asphalt concrete, the radial strain changes as alternative compression-tension way with the increase of loading distance, which has obvious mechanical response character, while there is no similar situation for cement concrete. （3） The region of pavement which is close to loading is in compressive state, while the region slightly away from loading is in tensile state. The load-typed top-down cracking of pavement developed from top surface crack may appear when load is too heavy. （4） The working state of pavement material can be reflected by utilization of the mechanical response test of the pavement structure model, which can be a good reference for calculating pavement structure and determining parameters of pavement material.