Energy Measurement in Standard Penetration Tests

The standard penetration test (SPT) is a widely used in situ method worldwide that can evaluate soil properties based on the blow counts (N-value). N-value depends properties, and energy transferred to drill pipe during hammering. Currently, European American scholars generally believe variation amount of hammer transmitted due different types drop systems primary factor leads variations N-value. In China, there lack research quantitative transfer efficiency system data from instrument. this study, an in-situ Jiangsu Province was performed at site using instruments are commonly China. Corresponding time history curves strain, acceleration, force, velocity, degree were obtained through stress wave test. propagation law analyzed, domestic SPT measured. test, most measured between 74.5 84.5%, average 0.3723 kJ; 78.7%; deviation (SD) 3.82, coefficient (CV) efficiency(ER) 4.9%. 78.7% be considered system. calculated results reported article improve level investigation. Based Er, home abroad corrected.