Cone Penetration Testing (CPT) - USGS
Figure by Tom Holzer, USGS. (Public domain.) Cone Penetration Testing (CPT) is used to identify subsurface conditions in the upper 100 ft of the subsurface. The USGS CPT uses a 23-ton truck to push a "cone" into the ground. The weight of the truck is partially supported by both the tip of the cone and the sleeve of the cone.