Effect of Ground Slope on the Dynamic Response of Piles Group in Liquefiable Soil based on 3D Numerical Simulation

Lateral spreading-induced soil liquefaction has imposed significant damage to the deep foundations of bridges, ports, offshore structures, and buildings. Despite various experimental, numerical, and field studies by previous researchers, there is also no comprehensive approach to assessing the effects of lateral spreading on pile groups. Numerical simulations are an economical tool for investigating and a means of representing the seismic performance of the pile groups at sites with liquefaction-induced lateral spreading.In this paper, the effects of various pile groups (e.g, of 1×1, 2×2, and 3×3) on reducing the potential for liquefaction during the earthquake are investigated parametrically, applying three-dimensional finite element (FE) simulations using OpenSees software. To examine the ground inclination angle and array of pile group effects, different models have been subjected to the El Centro (1940) earthquake. This study evaluates the effect of each of these factors on soil acceleration, lateral displacement, excess pore pressure and piles bending moment. The numerical model has been verified and calibrated in the literature through the analysis of well documented a large-scale (1-g) shake-table test.The results are shown that with increasing the ground slope angle, in a specified point of the soil, less pore water pressure is produced and the dissipation of pore water pressure starts earlier, but the variations of pore water pressure increase. In mildly sloping ground, with began of lateral deformations, soil heave occurs in the upslope and soil subsidence occurs in the downslope of the piles, and with increasing ground slope angle, the amount of these subsidence and heave increase. On the other hand, the ground slope angle is a very effective parameter in the lateral and vertical displacement of piles that should be considered in design code.