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. The “tip resistance” is determined by the force required to push the tip of the cone and the “sleeve friction” is determined by the force required to push the sleeve through the soil. The “friction ratio” is the ratio between sleeve friction and tip resistance, measured as a percentage. Soil type and thereby resistance to liquefaction can be inferred from these measurements.