The shear strength of infilled and slickensided discontinuities of some Hong Kong saprolites

The strength of infilled discontinuities within saprolites is difficult to obtain using standard laboratory testing equipment. Representative discontinuity strengths are important if slope stability is likely to be discontinuity controlled. As with rock-cut slopes, the identification of critical discontinuities within a saprolite slope is important and this can normally only be satisfactorily done by surface mapping of the slope during construction. This paper reviews the use of large-shear-box testing to obtain data for weak infilled discontinuities within a saprolite mass for two sites in Hong Kong.