Evaluation of driving energy transferred to split spoon sampler for accuracy improvement of standard penetration test

Uncertainties in the driving energy transferred to the split spoon sampler (E_sampler) cause inaccuracies of the standard penetration test (SPT) N values. In this study, an energy monitoring module (E-module) is developed to evaluate E_sampler and correct N. To demonstrate the application of the E-module, SPTs were performed at three study sites where the grounds are mainly composed of silty sands, and the transferred energy at the head of the driving rod (E_head) and E_sampler were evaluated. In addition, static penetration resistances were measured to validate the energy corrections of N. The experimental results and analyses indicate that the N corrected using E_sampler exhibits an improved relationship with static penetration resistances compared with that corrected using E_head because the E_sampler directly affects the penetration of the split spoon sampler. Therefore, the evaluation of E_sampler using the E-module and the correction of N may be used to obtain improved subsurface characterizations.