Effect of soil subgrade modulus on raft foundation behavior

Omer Mughieda,Mohamed Sherif Mehana,Kenan Hazirbaba

doi:10.1051/matecconf/201712006010

Omer Mughieda, Mohamed Sherif Mehana + Show 1 more

Open Access

https://doi.org/10.1051/matecconf/201712006010

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Abstract

The present study is carried out to investigate the effect of soil subgrade modulus on bending moment, shear, and deformation characteristics of raft foundation. Subgrade models are an approximate representation for the actual load-displacement behavior of the supporting soil. One of the widely-used methods to model soil subgrade modulus is “Winkler” method where the interaction between soil and foundations is represented by a number of springs. The main flaw of this model is the lack of coupling between springs and representation of the non-linearity of load settlement behavior of soil. In this work an attempt is made to analyze “Winkler” method through a commercial software (SAFE V2014) in terms of the effect of soil subgrade modulus on the behavior of raft foundation.

Highlights

The type of foundation used for any structure depends on various parameters such as geometric properties of the structure, super-structure loads, foundation material properties, foundation thickness and supporting soil sub-grade modulus
Use of a raft foundation proves to be more economical compared to spread footings in case spread footings would cover more than one third of structure footprint area [1]
A clear understanding of the behavior of raft foundation in relation to the supporting subgrade is mandatory to ensure the economy and safety in design, the objective of this paper is to examine the effect of supporting soil subgrade modulus on raft design

Summary

Introduction

The type of foundation used for any structure depends on various parameters such as geometric properties of the structure, super-structure loads, foundation material properties, foundation thickness and supporting soil sub-grade modulus. “Raft” or “Mat” foundation is commonly used in Abu Dhabi, UAE, especially to support low-rise building and light structures. Use of a raft foundation proves to be more economical compared to spread footings in case spread footings would cover more than one third of structure footprint area [1]. A clear understanding of the behavior of raft foundation in relation to the supporting subgrade is mandatory to ensure the economy and safety in design, the objective of this paper is to examine the effect of supporting soil subgrade modulus on raft design. This study focuses on the changes in raft straining actions and deflections due to the change in the value of soil subgrade reaction “Ks”

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