INVESTIGATION ON STABILIZATION OF A SAUDI SABKIIA SOIL

Hamad I. A1--Abdul Wahhab, Ibrahim M. Asi and Ornar S.B. Al-Amoudi

2nd Geotechnical Engineering Conference, Cairo University, fall. 10-13, 1994

ABSTRACT

Literature search indicates that sabkha improvement has been extensively used for large-scale construction, when the recommended methodologies include stone columns, dynamic compaction, use of geotextiles and pile foundations. For relatively small-scale construction such as highways and small buildings, the use of the above methods is not feasible and therefore classical methods of stabilization using lime, cement, asphalt, etc. should be researched. This is because sabkas have a very high salt content and therefore previous experience with conventional soils cannot directly be applied.

In this investigation, a typical sabkha from eastern Saudi Arabia was used. The soil was first classified using sieve analysis and Atterberg limits tests. The surface area was then determined using the centrifuge kerosene equivalent (CKE) test to preliminarily estimate the optimum asphalt dosage. Two types of liquid asphalts were used, namely emulsion and cutback, at four different percentages. In order to further improve the strength of the asphalt-stabilized sabkha, lime and cements were also added at three different weight percentages (0, 2 and 4%). Isotropically-consolidated triaxial tests were conducted to evaluate the performance of these stabilized sabkha specimens.

Although liquid asphalts did not bring about any improvement as anticipated, results of this investigation indicate that the sabkha properties (Ф and c) have improved significantly by the addition of cement to the emulsified asphalt. Properties of sabkha have been improved to a lesser extent when lime and emulsified asphalt were conjointly used. Emulsified asphalt at 4 % portland cement proved to be the best treatment.