ABSTRACT
This chapter examines some current practices, identifies some good practices and some of the instances where matters did not go to plan and what lessons were learned from some problematic projects; it closes with some comments on what lies ahead with respect to deep excavations. Stored geological and geotechnical information is now extensive in many countries and is continuously increasing as data is added to existing databases and more databases are created. A comprehensive guide to site investigation, including methods of drilling and sampling, equipment used, in-situ tests and laboratory tests can be found in Geoguide. The simplest form of identification of the ground is by the driller examining returned flushing water and the recovered parings of soil and rock fragments. Drillholes are mostly sunk from the ground surface. Many are vertical and some are inclined. One of the biggest changes of thinking within the industry during the last few decades has been the means of addressing and quantifying risk.
