"Direct Push Technologies, Overview, Applications and Limits"Cost efficient and sustainable remediation, especially with innovative in situ remediation technologies, requires detailed knowledge of the subsurface in view of the pollutant distribution and the hydrogeology. So far commonly site investigations based on boreholes are used for the characterization of contaminated sites. In most cases these methods are time consuming, costly and as a consequence the site characterization is based only on a few drillings, i.e. investigations points, which results typically in insufficient information about the "real" extend and location of the contamination.
An alternative approach for site investigation is the use of Direct Push (DP) technology. This technology refers to a growing family of tools used to obtain subsurface investigations by pushing and / or hammering small-diameter hollow steel rods into the ground. By attaching specialized probes to the end of the steel rods, it is possible to conduct high resolution logging of rock parameters as well as to collect soil, soil gas, and ground water samples. Using DP technology it is feasible to get very quick and on site information about the three-dimensional pollutant situation. This information serves as a basis for decision about the ongoing stepwise site investigation. So overall more information can be received at lower costs. Besides the broad applicability of DP technology, it also allows for a target-oriented installation of monitoring equipment.
Due to the development of new powerful machines and tools, the application of DP technology increased strongly during the last years and became a viable alternative to conventional methods for site investigation. With the new generation of DP machines several sounding locations can be completed per day. Furthermore, under ideal conditions (e.g. soft, unconsolidated sediments) depths of more than 50 m can be reached.
The presentation will give an overview about the various direct push technologies and will also show the benefits of these techniques for investigation of contaminated sites exemplary from case studies.