SPT dynamic analysis and measurements

Measurements of force and acceleration on SPT systems are discussed and evaluated using solutions from both wave mechanics and a wave equation analysis program. The results show that acceleration and force can be accurately measured during SPT operations with currently available transducers, and that the force and particle velocity calculated by wave equation analysis agrees well with both measurements and wave mechanics solutions. A study of energy transmission in the SPT system is included. This study was conducted using wave mechanics and wave equation analysis. The results show that to accurately calculate energy transmission, measurements of both force and acceleration must be available. The method that has been specified in ASTM D4633-86 can produce large errors. The wave equation analysis also indicates that the standard penetration test (SPT) blow count is affected by drill rod area for low blow counts.