宋小金 樊亮

摘 要：在实测4种沥青路面结构应力响应的基础上，系统研究了行车速度与不同深度下的荷载响应持续时间的关系。研究结果表明，行车荷载沿路线方向的应力影响的有效长度在速度为20 km/h左右时存在峰值，沥青结构层内应力响应的持续时间与行车速度、深度存在显著的非线性关系。通过非线性数据拟合，得到了行车速度大于20 km/h时的荷载时间与荷载速度和结构深度的关系式，该公式意义明确，相对于已有的理论方法，其拟合精度大为提高。对大于20 km/h的行车速度与路面荷载频率之间的关系进行分析，建立了行车速度与不同路面深度的荷载频率的关系，为室内试验有效模拟行车荷载提供了依据。

关键词：沥青路面；应力；速度；频率

中图分类号：U416.217 文献标志码：A

文章编号：1674—2974（2018）07—0071—06

Abstract： Based on the measured stress response of 4 kinds of asphalt pavement structures， the relationship between the driving speed and the load response duration under different depths was systematically studied. The results show that the effective length of the impact of the traffic load along the route direction has a peak at the speed of about 20km/h. There is a significant nonlinear relationship between the duration of the stress response in the asphalt structure and the speed and depth of the traffic. Through the nonlinear data fitting， the relationship between the load time and the load velocity and the structural depth when the driving speed is greater than 20km/h was obtained. The formula has clear meaning， and the fitting accuracy is greatly improved compared with the existing theoretical methods. The relationship between the driving speed of more than 20km/h and the road load frequency was analyzed， and the relationship between the driving speed and the load frequency of different pavement depth was established， which provides a basis for the effective simulation of the driving load in the laboratory.

Key words： asphalt pavements；stress；speed；frequency

瀝青材料具有黏弹性，其劲度模量对加载时间具有依赖性，实际沥青路面表现为应力脉冲时间越短，沥青混合料表现出的模量越大，具有高频高弹的特点[1-2].由于行车荷载对沥青路面具有连续、瞬时的冲击作用，其速度的变化影响着路面结构内的应力持续时间，因而沥青层材料在不同行车速度下，所表现出来的模量值是不同的，而对沥青路面的力学响应分析更是与行车速度紧密相关[3-5].

国内外对沥青路面应力脉冲和行车荷载因素的关系开展了一定的研究.1971年巴克斯达用有限元和弹性理论计算了柔性路面不同点位的竖向应力脉冲，得到了路面……