Evaluating the feasibility of inverted T foundation on expansive soils

Abstract

This paper presents a comprehensive design study conducted in Saudi Arabia, focusing on the performance evaluation of an inverted T foundation system in a building constructed on expansive soils. The study aimed to investigate the causes of damage and evaluate the performance of a proposed inverted T foundation. A single story market building in a semi-arid region with expansive soil was constructed utilizing a 40 cm-thick mat foundation as a precautionary measure against soil swelling. However, the building experienced instability and damage shortly after completion. This study explored the replacement of the existing mat foundation with an inverted T foundation. The research involved assessing the ability of the inverted T foundation to withstand swelling pressures and its impact on the structural members of the building. Design guidelines and tools were developed to support the design and analysis of the inverted T foundation. Economic feasibility was also evaluated. The study compared the effects of swelling pressure on two types of foundations: a mat foundation and a rigid strip foundation. The results showed that the inverted T foundation demonstrated less upward movement and was found more effective in mitigating the detrimental effects of soil expansion compared to the mat foundation. Design guidelines and tools, including schedules, and charts were developed to support the design and analysis of the inverted T foundation. The findings have significant implications for the design and construction of buildings on expansive soils, offering insights into the effectiveness of the inverted T foundation as an alternative solution. The research contributes to the knowledge of foundation design on expansive soils in general and provides practical guidance for engineers and practitioners in similar geological contexts.