Volume 4, Issue 1 (March 1981)
The Need for a Schema for the Classification of Transitional (Shale) Materials
The need for comprehensive information on the characteristics and behavior of earth materials has been recognized for many years. With the increase in size and importance of structures and facilities designed by engineers in recent years, there has been an increased interest in rock materials underlying the surficial soil layers. Many earth materials, however, are not readily classified as either soil or rock. These transitional materials comprise 50 to 75% of the sedimentary rock of the earth's crust and have been involved in a number of geotechnical engineering problems (slope stability, settlement, and bearing capacity failure) around the world. Various classification approaches are summarized and the continuing need to develop simple field and laboratory procedures for identifying, classifying, and evaluating transitional materials is discussed.