Undrained Strength and Stability Analysis for a Quick Sand

Abstract

This paper describes (1) the general characteristics of quick sand, (2) a method for the determination of the undrained strength of a quick sand which is located in the Arabian Gulf and (3) an example of a stability analysis of a structure constructed on this quick sand deposit. From a brief review on past studies on quick sand, it is first shown that the quick sand possesses quite different shear characteristics from the usual type of sand and is characterized by a liquefaction type failure under static shear conditions. From an examination of consolidated undrained strength tests performed on undisturbed and disturbed samples of a quick sand located in the Arabian Gulf, it is then shown that the undrained strength of this quick sand is almost the same as that of normally consolidated clay and that anisotropy in undrained strength is relatively greater than that of clay. Finally the results of a stability analysis for sliding of a structure (a rubble-mound breakwater) is shown. The analysis used undrained strength values for the quick sand and considered the effect of anisotropy in the undrained strength.