University of Khartoum

An Experimental Study on Collapsible Soils in Omdurman

An Experimental Study on Collapsible Soils in Omdurman

Show full item record

Title: An Experimental Study on Collapsible Soils in Omdurman
Author: Hamid, Wail Osman Mukhtar
Abstract: Collapsible soils are one of the common causes of foundation settlement around the world. Collapsible soils are unsaturated soils undergoing a radical particle rearrangement and considerable volume loss upon wetting with or without additional loading. This research was introduced to investigate the existing soils in parts of Omdurman and assess whether these soils are collapsible. In addition, preventive measures could be implemented on these soils to reduce the collapse potential. The research was initiated by visual inspection of existing buildings condition in Northern and Southern Omdurman for selecting study areas. It was found that many buildings in Elthawra Elhara-19 at Northern Omdurman experienced significant cracks and some of them have been partially damaged. Therefore two areas were selected in Omdurman. One was Elthawra Elhara-19, and the second area was Khartoum New Airport site at Southern Omdurman. Three test pits were excavated manually to 3m depth, two were excavated at Elthawra Elhara-19 and one was excavated at Khartoum New Airport site. Field density test was conducted by using sand replacement method at the center each 0.5 m with considering the top 0.5 m as backfilled layer and sixteen samples were taken from the three test pits. Moreover, undisturbed samples were taken from test pit excavated at Khartoum New Airport site. The soil samples were tested in the laboratory to obtain the in physical properties. Tests conducted included particles size distribution, Atterberg limits, specific gravity, and compaction tests. Single oedometer test was also performed on the undisturbed samples from Khartoum New Airport test pit and on compacted disturbed specimens from the same test pit prepared at moisture content equal to optimum moisture content of samples. The susceptibility of studied soils to collapse was identified by using reported collapse criteria based on the physical properties of soils as an indirect method. The results showed that the reported collapse criteria presented by different authors do not apply in most cases. It was found that the only way for direct identification of collapse potential of soils excavated from Elthawra Elhara-19 was through performing in-situ field plate load test. The identification of susceptibility of soil excavated from Khartoum New Airport site to collapse was achieved by performing single oedometer test on undisturbed specimens. The results showed the collapse ranged between 4.2 % to 8.3 % and the severity of collapse is moderate. The preventive measures for reducing this collapse potential was attempted by performing single oedometer test on compacted disturbed samples prepared at moisture content equal to optimum moisture content of samples. The results showed the collapse ranged between 0.75 % to 3.21 % and the severity of collapse is slight to moderate. The results indicated that the soil is collapsible and collapse potential could be significantly reduced by compaction.
Description: 103 page
URI: http://khartoumspace.uofk.edu/123456789/16876
Date: 2015-11-04


Files in this item

Files Size Format View

This item appears in the following Collection(s)

Show full item record

Share

Search DSpace


Browse

My Account