Table 7.26.

Guidance of spatial distribution of intrusive investigation from country codes and guides

Code/GuideSpacing (m)Associated comment
Euro Code
EN 1997-2:2007
20–200Where ground conditions are relatively uniform or the ground is known to have sufficient strength and stiffness, wider spacing or fewer exploration holes may be adopted. In either case, this choice should be justified by local experience.
US (EM 1110-2-1913)60–300Closer spacing in problem areas and wider spacing in ‘non-problem’ areas, with intelligent targeting of exploration holes around geological features.