The Self-Boring Pressuremeter (SBPM) has the capability to achieve testing in minimally disturbed, near-insitu conditions. This is done by the probe acting similar to a small tunnel-boring machine; the cutting shoe and rotating drag bit (or rock roller) cuts and flushes material out of the borehole, replacing the cut material instantly with the probe itself. This technique minimises the material relaxing upon the probe’s insertion, achieving a test in near-undisturbed conditions.

This instrument is best used in soils (drained or undrained). The two Pore Water Pressure Cells located 180 degrees from one another on the membrane measure and record the pore water pressure response both during insertion (drilling), and during the live test. The SBPM can also be used for permeability testing, to determine the insitu horizontal conductivity, as well as to perform consolidation testing, to determine the coefficient of consolidation and the lateral hydraulic conductivity.