Experimental investigation of laterally loaded piles in sand under multilayered conditions

In the present study, the lateral load responses and the lateral load capacities of piles in sand under multilayered conditions were investigated. For this purpose, a series of lateral load tests using two model piles was conducted within a calibration chamber under various multilayered soil conditions. The test results were then compared with those obtained under uniform soil conditions. Using the test results, the effect of the multilayered soil conditions on the design components for laterally loaded piles, such as the pile rotation point, the ultimate lateral load capacity, and the lateral soil pressure profile, were analyzed. It was found that the lateral load responses of piles are largely affected by the soil conditions near the surface and the pile base, while the effect of the conditions in the middle-depth layers is relatively small. It was also observed that the depth to the pile rotation point fluctuates during the initial loading, but then becomes stabilized as the level of the load is increased. No significant difference in the depths to the pile rotation point was observed between the uniform and the multilayered soil conditions. Based on the test results in this study, a modi- fied lateral pressure profile, applicable to the estimation of lateral pile load capacities, was proposed to more realistically reflect the effect of multilayered soil conditions.