Pile capacity testing means

A method of constructing cast-in-place concrete piles by which the static load bearing capacity of a pile is dynamically determined during its formation. In the disclosed method, successive charges of concrete are placed into a removable casing and subsequently driven into the soil by a drop hammer. The pile may be of the pedestal type having an enlarged base for increased load capacity. The pile shaft is formed by incrementally elevating the casing and driving concrete into a vertical series of annular enlargements corresponding to the points at which the lower end of the casing is stopped. The load capacity of the pile base and the individual enlargements is determined by measuring the resistance of the soil against penetration of the several concrete portions when driven by the hammer. This resistance is calculated as a product of the total mass of the concrete in motion and the hammer multiplied by the deceleration of the hammer and an adjustment factor to account for the effects of nonaxial concrete motion, energy losses, etc., at or about the time of zero velocity as determined by a decelerometer or any other suitable device mounted on the hammer.