Displacement-Based Simplified Calculation for Pile-Soil Interaction under Reciprocating Low-Cycle Pseudo-Static Loads

Abstract

Abstract A reciprocating low-cycle pseudo-static loading test on three reinforced concrete (RC) piles was performed in the Structural Laboratory of Fuzhou University to study their failure modes and seismic behaviors. The modified calculations of lateral deformation and soil pressure along the piles were further verified based on the test results. In this article, a displacement-based simplified calculation for pile-soil interaction of piles was proposed based on the shear equilibrium and test results, and then it was compared with the traditional m method and p-y curve method. The test results show that m method overestimated the bearing capacity of piles, leading to a lower safety factor for the piles. Therefore, it was not suitable to calculate the internal force and lateral displacement under large displacement. Moreover, the ductility of prestress high-strength concrete pipe piles or RC piles would be overestimated by the p-y curve method. Although the p-y curve method took into account the nonlinearity of soil, the calculated force-lateral displacement curve still showed a significant difference with the test results under large deformation. The test results further show that the modified calculation of lateral displacement and soil pressure can be preferably validated by test results, which indicates that the displacement law of laterally loaded pile can be accurately assessed. Furthermore, the proposed displacement-based simplified calculation showed a good agreement with the test values in terms of internal forces and force-lateral displacement curve. Therefore, it was recommended for analyzing the cyclic behavior of laterally loaded pile foundations considering soil-pile interaction in integral abutments jointless bridges (IAJBs).