ROAD SUBGRADE STRENGTH UNDER VARIOUS FLOODING EVENT

Abstract

Flooding and water inundation could result in great damage to road pavements. In principle, the design of pavement structure is based on the strength of compacted soil known as subgrade or road foundation. Therefore, subgrade is the major significant part of road structural systems. When roads are inundated for a long time or repeatedly, the materials in each layer of road structure become saturated, and then the original condition of subgrade soils will be compromised. This study investigated the effect on sub-grade strength and properties due to road submergence period and repeated submergence of road structural systems. Two types of soil that are normally used as the embankment soils in road construction, which can be categorized as cohesive and cohesionless materials were used in this study. California Bearing Ratio (CBR) test and Oedometer consolidation test were carried out on the various categories of inundation and loading conditions including repeated inundation. The findings indicated that the strength of subgrade materials were affected differently depending of inundation period and number of repeated inundation.