ABSTRACT
No project can be properly designed or constructed without a careful analysis of the conditions at its site or on its route. Meteorological and topographical conditions are often well documented and a matter of record. Disappointingly, the same is not true for subsurface conditions. While the subsurface state of the site or route can sometimes be surmised from local empirical data because other excavation has been carried out near the site or on the route, only full-scale earthwork will reveal what, if any, obstacles to construction are present below the surface. Both urban and rural areas can pose problems. In cities, buried streams, utility lines and old foundations are just some of the obstacles that can be unexpectedly uncovered. In less populated areas, underground boulders, caverns, unstable rock and natural wells can all complicate a job that was expected to be routine. Because unexpected conditions lead to delay and expense, a site or route survey should be undertaken well in advance of commencing any work in an attempt to anticipate what conditions will be encountered. The question of when, by whom and how this survey is done depends upon the commercial circumstances involved. In fact, in some projects such as highways, railroad and subways, a detailed survey of the route is often not feasible at all if the terrain is rough or the route is lengthy.
