Measurements of energy and dynamic force using instrumented SPT in a soil profile and wave propagation analysis

This article applies methodologies for direct computation of energy in the SPT test using accelerometer and strain data measurements by the force squared (EF2), the force-velocity integration method (EFV) and the calculation of the soil dynamic force (Fd). The measurements were done in a sandy clay deposit using an instrumented bar with strain gauges and piezoelectric accelerometers. Test energy efficiency and soil dynamic force (Fd) calculations were made along the profile. A numerical model for the instrumented SPT test was also implemented using the finite difference scheme proposed by Smith (1960) to simulate the wave propagation along the rods during the test. The possibilities and limitations of this application are discussed.