Sustainability issues related to the engineering geology of long linear developments

The development of long linear structures such as roads, rail roads, tunnels, canals and pipelines often has unique engineering geology challenges. These include geological modeling, the identification of material strength and support factors, stability and risk issues, material excavation characteristics and the proposal of techniques for overcoming geotechnical problems, which are normally assessed as part of the conventional engineering geological investigation. An additional factor that is becoming increasingly important but is seldom included in investigations is the sustainability of the geotechnical inputs, in contrast to the sustainability of the project which is generally included. Sustainability issues revolve around the non-renewable nature of most construction resources and there is no doubt that the injudicious use of these construction materials and construction water is not sustainable in the long term: it is thus essential that the engineering geo-logical investigation should take cognizance of such issues and be adapted to provide the design engineer with the information that will maximize the sustainability options. This will also require a closer on-going relation-ship between the engineering geologist and the design engineer. This paper highlights significant sustainability issues (note that these differ from conventional environmental issues) and suggests some mitigating solutions. The sustainability issues discussed include primarily material and water usage, with some reference to energy conservation (mostly through alternative material usage and processing techniques and transportation).