Effect of geometry and soil properties on the analysis of raft foundationansys program

Dissertant

Majid, Zayd Hamid

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Master

Degree Date

2006

English Abstract

A mat or raft foundation is usually a large concert slab supporting a number of columns or an entire structure.

Rafts often rest directly on soil or rocks ; however, they may be supported on piles as well.

In the majority of cases, raft foundations are used where the soil has low bearing capacity.

By combining all individual footings into one raft, not only is the unit pressure on the supporting soil reduced but the bearing capacity is often increase.

In this study, a nonlinear three-dimensional finite element analysis has been used to conduct an analytical investigation of the effect of raft foundation geometry and the soil properties.

ANSYS (version 5.4) computer program is adopted for that purpose.

ANSYS is presently recognized as one of the most widely used and.

The 8-node brick elements in ANSYS are used to represent the concrete of foundation and the soil under the foundation which are denoted by Solid 65 for concrete and Solid 45 for the soil.

Many finite element mesh sizes have been tried in order to model the raft foundation and the soil layer.

The fine mesh is eventually considered to be the most representative to the results.

The outcome of the analysis on a case study revealed that both raft dimensions and soil properties represented by the modulus of A elasticity (Es) and Poisson's ratio (v) play a vital role in changing tire values of maximum bending moments (Mx, My and Mz) and maximum displacements.

Finally the results obtained from ANSYS program were compared with the results by other programs, i.e.

(FOCALS) and (FEAR 4.0).

Program (FOCALS) by (Wardle and Fraser, 1970) who studied raft foundation resting on layered foundation using finite element method Program (FEAR 4.0) (Finite Element Analysis of rafts-Version 4.0) prepared by the University of Sydney, Center for Geotechnical Research.

Main Subjects

Civil Engineering

Topics

• Construction engineering
• Freemasonry
• Mechanics
• Soil physics
• Soil mechanics
• Architecture
• Walls

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305914