The effect of hysteresis on the resilient modulus (MR) of subgrade soils was investigated via a series of laboratory suction-controlled MR tests conducted on unsaturated, fine, sandy silt under cyclic suction. In other words, tests were performed at various suctions along the soil-water characteristic curve (SWCC) primary drainage, primary wetting, and secondary drying paths. A relationship between resilient modulus and suction, called theMR characteristic curve (MRCC), is obtained. Results indicate that the resilient modulus is dependent on the suction-stress history of the soil. For a given suction, specimens that underwent cyclic suction (i.e. drying followed by wetting) showed higher resilient modulus than those that underwent primary drying.
Samenvatting