Innovation in dynamic in-situ testing

Engineering parameters reflecting dynamic responses have been used for reliable subsurface characterization in the field. The objective of this study is to summarize the innovations in in situ devices using dynamic penetration systems. The devices cover the Instrumented Dynamic Cone Penetrometer (IDCP) in small- and large-scale energy-monitoring modules for Standard Penetration Tests (SPT) and Seismic Dynamic Cone Penetrometers (SDCP). For the IDCP, Dynamic Resistance (DR) was experimentally estimated by the F², F-V, and F methods and their reliability was compared, while the DR was correlated with the DCPI to assess its applicability in the field. The large-scale IDCP for the deep and dense layer estimates the DR as well, which shows the functions of relationships with the DCPI and static cone resistance. Likewise, an energy monitoring module was installed at the rod head and the SPT sampler. The transferred energy ratios acquired by the energy-monitoring module at the rod head and sampler were compared, and the DR was reasonably correlated with the static cone resistance. Finally, the SDCP simultaneously measured the penetration index and maximum shear modulus, which can characterize both strength and stiffness of the layer. This study suggests that the innovation of dynamic in situ devices may allow for more reliable and efficient subsurface characterization.