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本文是企图发展一种通用的方法来计算由于粘滞流动而使沥青层产生的残余变形。根据线性的、弹性多层理论,使用计算机程序,能够计算出在车轮荷载下道路中的应力应变分布。根据速度v=X/t的关系可以把静态的应力应变分布转换为“动态分布”。这样,在每一个给定点上的应力和应变便成为时间的函数。按照马克斯韦尔元件所表征的粘弹性性质的假设来计算一个车轮通过所引起的一个层次中的残余变形。总的车辙深度是通过总计所有粘弹性层次的不可回复的变形而得到的。缓冲器的粘滞度η是随着荷载次数而增加的时间因素,所以考虑这个因素是重要的。这样,在交通行驶下发生在沥青层中的“压实”现象就可以被描述出来。材料的特性从本文所叙述的无侧限压缩的蠕变试验中表示出来。考虑了影响车辙的下列条件:温度分布,车轮荷载的次数和大小,车轮通过的横向分布以及车辆速度。推荐的方法可以用来评定在不同气侯条件下为抵抗车辆作用力所要求的地沥青混合料的力学性质。虽然提出的方法是作为一种实际的工程设计方法,但对于评定不同地沥青混合料和不同结构组合的相对使用特性也是有用的。这个方法的正确性可以同自1972年以来在瑞士试验路所做的测定结果相比较而显示出来。通过从正常车道和错车道的地沥青层中野外取样测得的力学性质的比较可以看出压实的效果。
This article is an attempt to develop a general method to calculate the residual deformation of the asphalt layer due to viscous flow. According to the linear, elastic multi-layer theory, a computer program can be used to calculate the stress-strain distribution in the road under wheel loads. According to the relationship of velocity v = X / t, the static stress-strain distribution can be transformed into “dynamic distribution”. Thus, the stress and strain at each given point become a function of time. The residual deformation in a layer caused by the passage of a wheel is calculated on the assumption of the viscoelastic properties represented by Maxwell elements. The total rutting depth is obtained by combining the irrecoverable deformations of all viscoelastic layers. The viscosity η of the bumper is a time factor that increases with the number of loads, so it is important to consider this factor. In this way, the phenomenon of “compaction” occurred in the asphalt layer under traffic can be described. The properties of the material are shown in the creep tests without confinement compression described in this paper. Consider the following conditions that affect rutting: temperature distribution, the number and size of wheel loads, the lateral distribution of wheels passing, and vehicle speed. The recommended method can be used to assess the mechanical properties of asphalt mixtures required to resist vehicle forces under different climatic conditions. Although the proposed method is used as a practical engineering design method, it is also useful for assessing the relative use characteristics of different asphalt mixtures and different structural combinations. The correctness of this method can be compared with the results of the measurements made on the Swiss pilot road since 1972. The compaction effect can be seen by comparing the mechanical properties measured in the field from the asphaltic layers of normal and wrong lanes.