A one-story, 50-m wide X 90-m long manufacturing building is to be built on a site underlain by medium dense to dense silty sand with occasional gravel. This soil probably has better than-average engineering properties and average uniformity. There are no indications of previous grading or fill at this site, and the groundwater table is believed to be about 30 m below the ground surface. We anticipate supporting this building on spread footing foundations located about 0.5 m below the ground surface. There are no accessibility problems at this site.
(a) How many exploratory borings will be required, and to what depths should they be drilled?
(b) What type of drilling and sampling equipment would you recommend for this project?