Analysis of Piles and Piers Foundation Subjected to Lateral Load in Seismic and Static Condition

Abstract

A matrix procedure is presented to determine soil-foundation contact reaction and lateral displacement on piles and piers in seismic and static conditions. The method is obtained from the deformation compatibility between the soil mass and the foundation structure. The four boundary cases that can occur in professional practice are considered. The method takes into account the compressibility of the stratified soil mass, the rigidity of the foundation and the horizontal drag forces induced by the soil mass against the foundation during an earthquake. The procedure has the advantages of not being iterative, of being easily programmed and readily extended to other boundary conditions, such as other kinds of foundations -shallow and deep-, and different subsoil conditions. Furthermore, a method is disclosed for the stability analysis of foundation piles and piers subjected to lateral loading, both static and seismic conditions. The stability analysis for stratified soil is based upon the models of foundation soil-structure interaction and the Rankine’s theory of earth passive pressure. In addition, its application is simpler, and it can be solved using a spreadsheet. The Method considers the pore pressure generated in a fine saturated soil during an earthquake or during a rapid application of the horizontal load. The solution of two examples is shown, one in static condition and one in seismic condition, detailing the procedure step by step.