Installation of fully grouted piezometers

Abstract

In the planning and design phase of the E16 Sandvika – Wøyen road project in Bærum Municipality in Norway, NGI installed a large number of piezometers using the "Fully grouted" installation method. Because of layered soil conditions, with soft clay overlaying very hard moraine, traditional "push in place" installation method was not feasible for a large number of the planned sensors. Instead, a method that could ensure that sensors installed in both the clay and the moraine at the same locations had to be used. In total, 35 sensors were installed using the grout in place method, and two sensors were installed in the clay as control. The results from a pumping test performed in close proximity to the installed sensors, confirm that the installation method was successful, and that the sensors respond rapidly to changes in the in situ pore pressure.