DYNAMIC SOIL-STRUCTURE INTERACTION ANALYSIS: DETECTING THE RELIABILITY OF MODELLING THE PILES AS A PLATE ELEMENT FOR A MULTISTORY BUILDING RESTING ON DEEP FOUNDATION

Abstract

The assessment of seismic responses of buildings in dynamic-soil-pile-structure interaction problems has been one of the main interests among researchers in recent decades. Simulating such problems is usually done by two-dimensional models to overcome the difficulties encountered in 3D models. Commonly, piles were represented by plate elements of infinite length, disregarding the soil flowing between piles. Recently, Plaxis – a finite element software- implemented a new feature known as “the embedded pile row” that allows the definition of piles' out of plane spacing in a 2D model. Many researchers proved its validity in accurately simulating the real 3D pile’s behavior. The objective of this paper is to detect the reliability of modeling the piles as plate elements, by comparing the performance of the structural-pile system with the plate feature to that with the embedded pile row feature. A series of 2D finite element models are generated while varying the soil type, the earthquake frequency content, and the out-of-plane piles' spacing. This paper demonstrated that the building response with piles modeled as plate elements is just adequate when the surrounding soil is dense. Yet, regarding the pile response, the plate feature is unable to capture the real behavior for all soil types.