Estimation of Shaft and Base Resistances of Cast-in-Place Piles in Israel from Analysis of Pile Loading Tests

Existing approaches for the estimation of shaft and base resistances of drilled, cast-in-place piles have been compared on the basis of data collected from local geotechnical consultants, from load tests performed as part of foundation projects in Israel over the last decades. Three typical Israeli foundation soils were considered-clay, sand, and kurkar (partially and variably cemented sand). Data from 18 load tests at 13 sites were used for the study. Existing correlations were first used to estimate relevant soil properties from results of in-situ tests [usually standard penetration tests (SPT) or vane shear tests] performed during the project site investigations. These properties were then inserted in existing resistance estimation expressions. The resulting estimated resistances were compared to resistances indicated in the loading tests. A statistical analysis was used to choose the most reliable correlations and resistance estimation expressions for piles embedded in the various soils.