EVALUATION AND IMPROVEMENT OF EASTERN SAUDI CALCAROUS SEDIMENT FOR CONSTRUCTIONAL PURPOSES

Saad A. Aiban, Hamad I. AI-Abdul Wahhab And Omar S.B. AI-Amoudi

ABSTRACT:

During the last two decades, the Arabian Gulf countries have gone through a spectacular phase of both industrialization and infrastructure establishment. Many of these unprecedented activities resulted in some unexpected post constructional problems attributed to the lack of proper quality soil coupled with the unfamiliarity with the inferior properties of these soils. Many ground improvement techniques have been used in most of the large projects; however the ground improvement for the small projects has not been utilized to meet the demand and the environmental requirements of the eastern province of the Kingdom. This makes it necessary to investigate the geotechnical problems that are related to road construction in order to come up with appropriate stabilization techniques for the local soils. Many investigations have been conducted on eastern Saudi soils and results have indicated that the calcareous material known locally as "marl" which is heavily utilized in construction has acute water sensitivity. Such sensitivity could reduce the CBR from over 200 to less than 10. Results have also indicated that the additions of low percentages of Portland cement (less than 4 %) increases the strength, reduces water sensitivity improves the durability of the treated calcareous sediments. The findings were utilized in the construction of a few field trial sections. The performance of the sections was excellent for the past seven years. This encouraged the modification of road construction in the area. In this research, the problems associated with the calcareous sediments and the ways and means for their improvement as well as the quality control procedure and the modification of the standards will be discussed.