Characterization of Swelling Potential of Shale Strata

Shale has long been recognized for its tendency to swell when exposed to the atmosphere. Interaction of moisture with exposed shale strata can cause serious ground stabi1ity problems, since the initial strength of a shale is reduced if the material is sensitive to moisture variations. In this paper, the authors present a classification system to estimate the response of swelling generated within shales. This characterization of the swelling potential is based upon plasticity, susceptibility to moisture, mineralogical constituents of clay size particles, and fabric. Use of this classification system in conjunction with other existing rock properties tests will provide data for more rational engineering design.