Correlation between Resilient Modulus MR and Deviator Stress for Subgrade soils of northern provinces in Vietnam

Abstract

Recently, Resilient Modulus is applied in pavement structural design in Vietnam. The resilient modulus of subgrade soil is an essential input parameter for a flexible pavement design. The resilient modulus depends on soil properties, stress state, and soil type. However, there is limited research on resilient modulus of soils and models to estimate resilient modulus in Vietnam. Therefore, in this study, soil samples were collected from two provinces in northern Vietnam, namely Bac Giang province and Ninh Binh province, and then physical and mechanical tests were conducted for these samples. In addition, a series of cyclic triaxial tests also conducted according to AASHTO T307 specification to obtain resilient modulus of these soils. The results showed that the resilient modulus decreased with the increase of deviator stress for Bac Giang samples and increased with the increase of deviator stress in the case of Ninh Binh samples. Simple deviator stress models have developed to estimate a resilient modulus of soils in the area.

Keywords

• resilient modulus subgrade cyclic triaxial test