Assessing the Bearing Capacity of Backfills by Stress Wave Velocity and Cone Penetration Resistance

Abstract

AbstractSand-cone test is one of the most common tests performed to assess the compaction quality of backfills for earth works. However, performing such test is time consuming and can only obtain the density and water content of backfills. In order to obtain their engineering properties, such as strength or bearing capacity, additional tests such as California Bearing Ratio (CBR) test or plate loading test must be performed. In this study, a miniature dynamic cone penetrometer was developed. The feasibility of assessing the bearing capacity of backfills by stress wave velocity and dynamic cone penetration resistance was investigated. Samples of a silty clay were compacted with various compaction energy and moisture contents. In addition to the density and moisture content, the CBR, P-wave and S-wave velocity, as well as penetration resistance of a mini cone of these samples were measured. Linear relationships between the CBR and S-wave velocity/penetration resistance were found. Therefore, it is feasible to assess the bearing capacity of backfills by these two techniques.