Basic design parameters for different stone columin configurations

Dissertant

al-Mahdi, Asil Salib

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Master

Degree Date

2002

English Abstract

The present work sheds the light on the evaluation most important parameters, the area replacement ratio and the length to diameter, regarding the design of soft soil reinforced with stone columns.

The ordinary stone columns have been modified to increase their efficiency by either the enlarged base technique or by using the concrete plug technique. The investigation was carried out through model tests performed on soft saturated bed of soil, 400mm in depth, with undrained shear strength, ranges between 7, 5 to 8 kN / m2 , Circular footings 60.

70, 80 and 100mm, in diameter, resting on the bed of soil were loaded incrementally up to failure. Three series of model test were performed, the first consists of ordinary stone columns.

The second covers the model tests with enlarged base while the third, was concerned with stone column with concrete plug, The influence of area replacement ratio and length to diameter ratio was detected from the results of the first series.

Both bearing improvement ratio and settlement reduction ratio have a dominate-effect OR the overall behavior of the composite soil. The presence of the enlarged base caused a substantial increase in the load carrying capacity that reached about 3.5 times the load carrying capacity of the ordinary stone columns when the area replacement ratio is 0.72. The concrete plug technique provided an encouraging result in controlling both the load carrying capacity and the settlement with plug length to column length ratio between 0.2 to 0.4.

A proposed increases in bearing improvement ratio (from 4 to 4.5 for area replacement ratio equal 0.72).

Also the settlement reduction ratio is decreases from 0.09 to 0.05.

Main Subjects

Civil Engineering

Topics

• Construction engineering
• Freemasonry
• Soil mechanics
• Architecture
• Walls
• Concrete columns

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305621