English abstract
During the last decades, the Arabian Gulf countries have gone through a spectacular phase of development. Inevitably, this resulted in utilization of virgin lands and large scale urbanization development programs. As Gulf countries have large coastal areas, the development programs included many construction sites in the coastal areas. During the geotechnical surveys which were created in these areas for investigation purposes by different researchers, some geotechnical problems were reported. One of the typical problems is the presence of the sabkha soil. The sabkha soils are problematic soils and they are characterized by the presence of salts. The type and amount of salt greatly affect the engineering properties of the soil. When the soil is dry, the salt is considered as a bonding agent that will increase the shear strength and reduce the compressibility of the soil. When the soil gets saturated, the salt dissolved resulting in a loose fabric soil causing an increase in the soil compressibility. This may lead the soil to collapse.
The purpose of this research was to investigate the load carrying capacity of sabkha soil using geogrid reinforcement and to investigate the effect of using geogrids on the performance of sabkha soil. The sabkha soil was collected from Al-Auzayba area, 2 km east of Muscat International Airport. The general geotechnical tests were conducted to investigate the engineering properties of the soil. Two testing models were used to carry out the loading tests.
The results obtained indicated that load carrying capacity of sabkha soil was very low especially when the soil was soaked. The use of geogrid in sabkha soil improved the load carrying capacity of sabkha. Sabkha- geogrid system can carry higher loads than the system without geogrids, particularly
in the soaked condition. The improvement on the load carrying capacity of soaked sabkha has a relation with numbers and spacing of the geogrid membranes. As the spacing decreases and the number of geogrid increases, the load carrying capacity of soaked sabkha increases. Also economical
analysis was conducted to compare the cost of geogrid as stabilization material with cost of cement stabilization system from which it was found that geogrid stabilization system is more economic than mixing sabkha with cement.
