Analysis of raft foundation with geofoam for earthquake resistant

Abstract

It is becoming a great challenge for civil engineers to design a foundation with able to restrain form an earthquake. The paper presents the settlements of raft foundation (static load) and the effects of raft foundation (include building on it) that expose to an earthquake. In this process, geofoam, Expanded Polystyrene (EPS) is placed under foundation. The properties of this type of geofoam is super-lightweight closed cell, rigid, plastic foam. High strength give best option as fill for poor quality of soil. The various types and thickness of EPS under the foundation on soft soil are studied. A numerical finite element analysis program, PLAXIS 8.2 is used to simulate the problem. Earthquake cause shaking of the ground in all three direction, along the two horizontal directions (x axis, left and right) and the vertical direction (y axis). The purpose of this analysis is to find the settlement that might occur under the foundation that use Geofoam (EPS) and compare to not use Geofoam (EPS) and also to analyze its effects against earthquakes through software PLAXIS. In this project, various types and thickness of Geofoam (EPS), constant distributed load that acting on foundation and also constant dimension of raft foundation is used for this analysis.This analysis could be considered successful since the objectives is succeed.From the result of settlement under the raft foundation with and without using Geofoam (EPS) on soft soil, it can be conclude that higher density of Geofoam (EPS) have less effect on settlement and also Geofoam (EPS) thicknesses can affect the settlement which mean that higher thickness will cause higher settlement.