Automatic SPT monitor

Abstract

An apparatus is used with an impact hammer penetration assemble such as standard penetration test (SPT) in geotechnical engineering. The impact hammer penetration assembly comprises a penetration sample, a series of rods coupled together and an impact hammer apparatus. The drop of the hammer from a constant height hits the coupled rods and sampler in series and forces the sampler deeper into the ground. The apparatus includes a tip depth transducer and sampler to output a first electrical signal that is a function of the sampler tip position. A shock force transducer communicates the axial shock force in the rod to output a second electrical signal that is a function of the rod shock force and hammer blows.; A shock penetration transducer communicates the movement of the coupled rods and sampler to output a third electrical signal that is a function of the sampler penetration due to the hammer blows. A micro-process controller monitors and processes the first, second and third signals in real time.