Geotechnical consequences of ground motion: hazard perspectives

Abstract

Following the 13 April 1992 Roermond earthquake, areas of the Netherlands experienced severe shaking and suffered ground failures, particularly ground cracking, sand injections, and shallow local landslips. Such phenomena are well documented in historical case histories of large earthquakes in many areas of the world: famous examples of widespread failure are reviewed and the key phenomena identified, e.g. Assam (1899) and Alaska (1964). The geotechnical conditions and consequences resulting from strong ground motions are emphasized and important applications in earthquake hazard assessment are discussed in the context of readily available literature. Liquefaction and kindred state changes leading to mass failure, settlement, and flow-slide behaviour are considered for cases of water-saturated sandy and silty deposits. A simple classification is required to facilitate discussion of strong motion domains; these being nearfield, proximal farfield, and distal farfield. Volume changes, dewatering and displacement patterns provide insights into hazard assessment applications, amongst which three are considered: (i) intensity scaling effects, with a scheme appropriate to north-west Europe, (ii) in situ measurement by Standard and Cone Penetration Tests (SPTs and CPTs), and (iii) palaeoseismology. The potential of finding palaeoliquefaction phenomena in the southern Netherlands is considered to be high in the vicinity of certain faults. The importance of palaeoseismology is evaluated with relevant world-wide research perspectives regarding palaeoliquefaction. Recommendations are given to encourage research initiatives.