Location

Chicago, Illinois

Session Start Date

4-29-2013

Session End Date

5-11-2013

Abstract

The city of Hyderabad is a part of lower Indus Basin with arid-tropical climatic conditions. Geologically, the soil deposits near Hyderabad are of alluvial-loessic nature underlain by limestone beds alternating with clay layers. Groundwater is present at shallow depth which fluctuates to even shallower depths during monsoon season in the months of July and August. In recent past, large number of buildings built over shallow foundations in the city suffered structural damages of varying scale in the form of cracks and settlements. Some of these buildings were declared dangerous from safety and stability view point and got vacated by local administration. A forensic geotechnical distress evaluation was carried out to identify the causes and process of damages. The study comprised survey of structural distresses and review of original geotechnical investigation report, selected design parameters, construction materials used and quality controls implemented. Additional geotechnical field and lab investigations using conventional and geophysical techniques were carried out to characterize the existing foundation soil conditions. Presence of problematic soil layers of swelling nature were found within the zone of influence of all the damaged structures. Investigations indicate swell pressure to be the major source of distresses leading to foundation failure. Leakages of water from supply lines, sewerage pipes and fluctuating ground water table are identified as the sources of water responsible for swelling. The paper includes detailed methodology of geotechnical distress evaluation, recommendations to enhance geotechnical investigation for problematic soils and selection of appropriate design parameters. It is hoped the lessons learnt from this case history would enhance practical geotechnical engineering practices in Pakistan and elsewhere.

Department(s)

Civil, Architectural and Environmental Engineering

Appears In

International Conference on Case Histories in Geotechnical Engineering

Meeting Name

Seventh Conference

Publisher

Missouri University of Science and Technology

Publication Date

4-29-2013

Document Version

Final Version

Rights

© 2013 Missouri University of Science and Technology, All rights reserved.

Document Type

Article - Conference proceedings

File Type

text

Language

English

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Apr 29th, 12:00 AM May 11th, 12:00 AM

Forensic Geotechnical Distress Evaluation of Damaged Buildings in Alluvial-Loessic Soils; A Case History

Chicago, Illinois

The city of Hyderabad is a part of lower Indus Basin with arid-tropical climatic conditions. Geologically, the soil deposits near Hyderabad are of alluvial-loessic nature underlain by limestone beds alternating with clay layers. Groundwater is present at shallow depth which fluctuates to even shallower depths during monsoon season in the months of July and August. In recent past, large number of buildings built over shallow foundations in the city suffered structural damages of varying scale in the form of cracks and settlements. Some of these buildings were declared dangerous from safety and stability view point and got vacated by local administration. A forensic geotechnical distress evaluation was carried out to identify the causes and process of damages. The study comprised survey of structural distresses and review of original geotechnical investigation report, selected design parameters, construction materials used and quality controls implemented. Additional geotechnical field and lab investigations using conventional and geophysical techniques were carried out to characterize the existing foundation soil conditions. Presence of problematic soil layers of swelling nature were found within the zone of influence of all the damaged structures. Investigations indicate swell pressure to be the major source of distresses leading to foundation failure. Leakages of water from supply lines, sewerage pipes and fluctuating ground water table are identified as the sources of water responsible for swelling. The paper includes detailed methodology of geotechnical distress evaluation, recommendations to enhance geotechnical investigation for problematic soils and selection of appropriate design parameters. It is hoped the lessons learnt from this case history would enhance practical geotechnical engineering practices in Pakistan and elsewhere.