ABSTRACT
This paper presents an experimental study to evaluate the effects of water content on the mechanical behavior of a base course material subjected to moving wheel loads in case the degree of saturation varies due to rainfall and change of ground water level. In this paper, a series of laboratory element tests and model tests were performed with gravel under airdried and saturated conditions. First, to understand the mechanical behavior of granular roadbed under traffic loads, two types of small scale model tests which adopt a fixed-place loading method and a moving loading method are performed. Here, the former is a method for applying pulsating compression vertical loads to a paved road, while the latter is a method for making a wheel with a constant vertical load travel on the paved road like actual traffic loading. Next, to examine the mechanical characteristics of the base course material subjected to moving wheel loads, two types of multi-ring shear tests which differ in loading method are performed. Here, the multi-ring shear test, which can apply torsional simple shear for gravel and then consider a change in direction of principal stresses like traffic loads, is newly developed as a laboratory element test (Ishikawa et al. 2007).
