Instrumented dynamic cone penetrometer incorporated with time domain reflectometry

In this study, an instrumented dynamic cone penetrometer incorporated with time domain reflectometry (IDPT) is developed to provide portable in-situ penetrometer for evaluation of ground strength and water content. The IDPT probe combines cone tip energy module with accelerometer and load cell, and time domain reflectometry (TDR) probe to simultaneously obtain transferred energy and water content. The IDPT is applied to embankment with dynamic cone penetrometer (DCP) and penetrometer incorporated with TDR probe (TDRP). In addition, the strength and water content of ground in rainfall conditions are characterized with time. Penetration indices of IDPT and DCP show similar trends in ground strength characterization, and volumetric water contents detected by IDPT and TDRP are almost identical. As water infiltrates the ground with time, the penetration index and volumetric water content increase. This study suggests that the IDPT may be effectively used for the simultaneous evaluation of ground strength and water content.