DYNAMIC PROBING (DPSH) INVESTIGATION FOR EMBANKMENTS AND BACK-FILL IN SEQUENTIAL EXTRACTIVE LAND USE

Abstract

Extractive land use, such as quarrying for construction materials, is typically progressed by excavating pits, constructing bridging embankments, and back-filling pits with overburdened or processed waste materials.  Collection of geotechnical data at various stages of the extraction and back-filling activities can provide a valuable record of the history of the ground conditions and provide input to the assessment of land use options when back-filling is complete. A mechanized dynamic probe in the super heavy category (DPSH) has been used in recent investigations as the primary tool for geotechnical data collection in these rapidly changing environments. In addition, data from a combination of lightweight manual dynamic probes (DCP), cone penetration testing (CPT), standard penetration testing (SPT), and installed settlement plates have been collected, allowing a comparison of the methods. The condition of embankments formed on the batter of open pits and temporary embankments forming land bridges between pits can be effectively assessed using these techniques. Backfill of pits with site materials or with imported material should be progressively monitored and assessed for suitability and/or ground improvement requirements for future land uses.