Forensic Distress Evaluation of Damaged Building at Hyderabad

Abstract

Hyderabad, Sindh Pakistan 25.637 N latitude and 68.367 E longitude and elevation of 13m is located on east bank of Indus river, is composed of alluvial-loessic soil deposits underlain by limestone beds alternating with clay layers. The climate is hot desert and the region is typically an arid tropical region. Buildings located in and around Hyderabad have experienced settlements of moderate to major scale. Recently, a large number of buildings have been declared unsafe by the city authorities due to cracks and other damages resulting from excessive settlements. Geotechnical distress evaluation of damaged buildings was carried out to ascertain the causes of failure using conventional and geophysical techniques. Several tests were carried out on the field. Geophysical testing at selected sites confirms the presence of a thick layer of problematic soil which is reasonably uniform in lateral directions. The problem with the soil is that it showed excellent strength when dry but on addition of moisture, it lost its strength. Stabilization of soil was studied using a number of commercially available admixtures and grouts. The study concludes that the engineering properties of foundation soil can be improved in an economical way using locally available materials and thus the problem may be avoided in future and the abandoned buildings can be rehabilitated saving a significant amount of money