Influence of Soil Type and Loading Conditions on the Bearing Capacity of Pile Groups

Analyzing the behavior of piles, particularly for large marine structures, under cyclic loading —both horizontal and axial —is crucial due to the potential consequences of failure. This research aims to investigate how various factors affect axial cyclic loads on the bearing capacity of (۲*۲) pile groups in sandy soils. The study employs both static and dynamic analyses on ۴-member pile groups using Abaqus finite element software. Parameters under scrutiny include load capacity, dynamic load effects, and a parametric analysis of influential factors. Natural frequency, approximately ۴ Hz, obtained via frequency analysis, is used for loading, typically over ۱.۲ seconds, except when analyzing the effect of time. Piles are constructed from concrete, while sandy loose soil is utilized. Dynamic loading in the form of sinusoidal and harmonic stress is applied. The criterion for assessing load capacity is a ۲.۵ cm settlement of the pile group. Findings indicate that dynamic loading diminishes bearing capacity more in pile groups with more piles relative to static loading. A parametric study reveals that soil stiffness (soil elastic modulus) influences dynamic load bearing capacity, with a lesser effect in looser soil —bearing capacity decreases by ۲۲% in loose soil, ۲۸% in medium soil, and ۳۲% in dense soil compared to static conditions.

کلیدواژه ها:

cyclic loading ، pile group ، dynamic loading