干线公路沥青路面水平裂缝破坏力学机理研究及对策

Research and Countermeasures on the Damage Mechanics Mechanism of the Horizontal Cracks in the Asphalt Pavement of Arterial Highway

以干线公路半刚性基层沥青路面产生的水平裂缝为研究对象,采用力学分析软件计算在标准轴载和超载作用下的力学响应。通过对路面结构层应力应变特性及最大剪应力随深度变化特点分析,结合路面实际破坏现象,揭示了干线公路半刚性基层破坏的根本原因在于:沥青面层薄,高剪应力区位于半刚性基层上,半刚性基层竖向受剪超过其抗剪强度就产生水平裂缝。为提高半刚性基层疲劳寿命,避免路面早期病害,应采取如下措施:结构层中沥青路面厚度至少提高到12cm,施工中基层应采用一次压实成型,形成整体性好的高性能半刚性基层,同时养生期严格控制车辆通行。

The horizontal cracks produced by semi rigid base asphalt pavement on trunk highway being the study ohject, the mechanical response of the standard axle load and overload is calculated by means of mechanical analysis software. Through analysis of the characteristics of stress and strain and the change of maximum shear stress with depth of pavement structural layer, combined with the actual pavement damage, the basic reason for the destruction of the semi-rigid base of the trunk road is revealed, the asphalt surface is thin, and the high shear stress zone is located on the semi rigid base, semi rigid base vertical shear exceeds its shear strength to produce horizontal cracks. In order to improve the fatigue life of semi rigid base, following measures should be taken to avoid the early diseases of pavement： the thickness of asphalt pavement is increased as least to 12cm, and during construction, the base course should be compacted and formed in one time in order to construct good overall performance semi-rigid base, and at the same time strict control of vehicle access shall he made during curing period.