Evaluation of Lateral Interpretation Criteria for Drilled Shaft Capacity in Gravels

Representative interpretation criteria are examined in detail to evaluate the lateral response of drilled shaft foundations in gravels. A database of field lateral load tests is used for the analysis. The representative criteria are subdivided into absolute displacement, displacement as a function of shaft diameter, rotation limit, mathematical model, and graphical construction method. Comparison of these criteria shows that the initial elastic region ends at approximately 3-5 mm, 0.50 % B, and 0.08 degrees rotation, which represent the serviceability limit state. The final region begins at about 25 mm, 2.5 % B, and 0.33 degrees rotation, which represent the ultimate limit state. The graphical construction methods, QL and QS& W, are located within the transition region of the curve. Among these criteria, the displacement limits, QL, and QS& W methods demonstrate more reliable results. The typical load-displacement curves for lateral capacity in gravels are developed for engineering practical use. Further, recommendations for the use of these interpretation criteria are also given.