ENGINEERING GEOLOGY/Overview 445 ground This requires defining the state of the ground conditions: the geometry of the various soil and rock units, locating their boundaries; determining their structure, composition and (geotechnical) properties; identifying displacements or distortions (actual or potential), for instance those arising from neotectonic forces (stress), mining or excavation; and identifying the presence of fluids within and flow through the units comprising the ground profile Three disciplines are particularly important for the synthesis of engineering geology: hydrogeology, soil mechanics, and rock mechanics Engineering geology facilitates their integration with the science of geology, particularly by bringing to bear the skills of observation, balancing idealization with reality, and injecting both experience and sound judgement Hydrogeology concerns the character of fluids (water and gas) within the ground (as distinct from hydrology which concerns fluid flow, generally at the surface), whereas soil mechanics and rock mechanics are engineering disciplines, together forming the profession of geotechnical engineering Each activity has its own distinct methodology and its own rigour Each is interlinked and so there is a need to strive towards coherence and integration The term ‘environmental geology’ has evolved relatively recently, but as a discipline is really a component of engineering geology, concentrating on issues related to our industrial legacy, in particular the chemical character of the ground and groundwater, with focus on contaminated land The Profession Another term requires consideration: ‘geological engineering’ The distinction between this and ‘engineering geology’ lies in the requirements of the engineering institutions Accreditation of education and training falls within the remit of these professional institutions They set levels of training if direct registration of the individual is to be approved, such as the minimum time devoted to subjects like mathematics, mechanics, and design In the United States, this is undertaken by the Accreditation Board for Engineering and Technology (ABET), leading to appointment as a Professional Engineer (PE); in the United Kingdom this is done by the Engineering Council (EC), leading to appointment as a Chartered Engineer (CEng) Such accredited courses are commonly entitled ‘Geological Engineering’, especially in the USA The training of a ‘Geological Engineer’ in essence follows that of an engineer with additional geological knowledge, whereas the ‘Engineering Geologist’ remains a scientist; this difference has ramifications for professional registration and professional indemnity A relatively new route is now opening up for those working primarily within geoscience, accredited by the Geological Society of London, which leads to appointment as a Chartered Geologist (CGeol) This accreditation is also accepted by the European Federation of Geologists, qualifying the registrant as a Euro Geologist (Eur Geol), equivalent to a Euro Engineer (Eur Ing), but only the latter currently has legal standing Development Engineering geology addresses the issues resulting from adverse ground behaviour Records of early applications may be traced back five millennia, to the Ancient Egyptians mitigating the impact of flooding by the River Nile and constructing the Pyramids There follow records of the Romans and Medieval Europeans utilising their understanding of engineering geology in a wide range of public works as well as for the extraction of mineral resources and support of military campaigns, notably sapping and mining In the early nineteenth century, the creator of the first comprehensive geological map of England and Wales, the engineer William Smith, expressed the essence of an engineering geologist, applying geological principles (largely stratigraphic) to the design and construction of the British canal system as well as to groundwater control However, the development of engineering geology as a recognizable discipline in its own right arguably had to wait until the early twentieth century and realization of the important impact of geology on civil engineering This was exemplified by failure of slopes along the Panama Canal in the first decade and the devastation brought about by the 1906 San Francisco earthquake, focusing attention to the wider potential adverse impact of the ground on the built environment This encouraged the pioneering work by Karl Terzaghi, transcending the disciplinary boundaries between the science of geology and the art of engineering, seeding the growth of the geotechnical profession worldwide Publication lagged behind the increased understanding of ground behaviour that was being developed within the construction industry, from research underway in government-funded establishments, and from the lectures being delivered to engineering institutions and university students Books containing ‘engineering geology’ in the title had been published by the 1880s, for instance the volume by Henry Penning, but were not widely distributed