Dynamic Soil Reactions around a Beam-on-Multiple-Piles Structure and their Application in the Parallel Seismic Integrity Test

In this paper, an analytical solution to the dynamic reaction of half-space soil around a beam-on-multiple-piles structure is proposed. This can be used to evaluate the effect of an adjacent vibrating pile of unequal length or pile defects on parallel seismic (PS) integrity test results. The structure-soil interaction (SSI) problem was decomposed into a beam-multiple-pile coupled vibrating model and an extended half-space soil model. The surrounding soil reactions were calculated employing the half-space soil excited by known vibration (HEKV) solution scheme. The HEKV solution scheme and the accuracy of the analytical results were validated through comparisons with finite-element analysis (FEA). The validated model was then used to study the influence of an adjacent vibrating pile on the pile response, and to optimize the selection of technical parameters for the PS test. The obtained results were used to discuss the uncertainties of the PS test in terms of multiple-pile foundations and adjacent vibrating piles, and to develop the theoretical basis for testing multiple-pile foundations. Finally, practical guidance is provided for the application of the PS test to multiple-pile foundations in practice.