Miscellaneous Experiments with Pressuremeters

Abstract

This chapter considers some of the fringe uses and trials applied to the pressuremeter and its test. In position BH18, a cone pressuremeter (CPM) with a dummy cone was pushed from 6 to 7 metres, so that the centre of its inflation point was in a similar plane to that of the SBP. A quick undrained test was carried out with the CPM. The expansion is plotted as radial displacement for maximum definition but expressed as cavity strain, the CPM test has expanded four times further than the self-boring pressuremeter tests. Experimental pressuremeter testing in the clay immediately surrounding the tunnel was carried out soon after the initial test drift was completed. After further construction, a programme of self-bored and pre-bored pressuremeter testing was carried out between 1999 and 2009. These were along and across the tunnel alignment, the latter boreholes being horizontal, vertical and angled.