Double cone pressure meter

TLDR: A double cone pressure meter has a body (1) in the shape of two hollow cones placed base to base as mentioned in this paper, which is pushed downwards into the ground, the solid nature of the variable diameter fixed body forces the surrounding soil at a particular level to deflect radially outwards and then inwards in a controlled manner and at a predetermined rate.

Abstract: A double cone pressuremeter has a body (1) in the shape of two hollow cones placed base to base. As the device is pushed downwards into the ground, the solid nature of the variable diameter fixed body (1) forces the surrounding soil at a particular level to deflect radially outwards and then inwards in a controlled manner and at a predetermined rate in order to force upon the soil the type of deformation required to carry out a pressuremeter test. Strain gauged circular hoops (10) set flush with the outer surface of the device measure the soil pressure. Drilling fluid passes down a pipe (5) and is removed together with soil or rock waste via the annulus between the pipe (5) and body (1). Water pressure is measured by sensors (11).