Piz Nair – Monitoring the stability of the rock mass

Piz Nair - Monitoring the stability of the rock mass

The Challenge

At the Piz Nair summit, a mountain located near Sankt Moritz in the Albula Alps in Switzerland, at over 3,000 m, Huggenberger AG has provided instrumentation and collaborated in the installation of a measuring system to monitor the stability of the rock mass. The instrumentation was produced by its parent company SISGEO SRL. The purpose of the system is to measure the movements and rock temperature of the rock mass in correlation with the variations in temperature, related to global warming.

The Solution

The installation conditions of the instruments are extremely strict and it has therefore been decided to drill no. 5 boreholes 18 meters deep. The boreholes are equipped with telescopic ABS inclinometer casing, manual vertical deformation measurement with 14-level magnetic references plus temperature measurement strings (thermometer chains) with 16 high precise temperature sensors per borehole.

The Results

The acquisition of data concerning the deformation (vertical settlements and rock mass temperature) will be carried out with manual operated and systems the BRAIN-borehole inclinometer and magnetic extensometer. In a later phase of the project this might be converted to automatic mode, using the MD-Profile in-place-inclinometer. The temperature sensors (16 PT100-sensors per borehole) are measured automatically with Sisgeo's OmniaLog- data acquisition system. Huggenberger AG in close collaboration with the geotechnical engineer Thomas Rüegg and the drilling company Geo-Grischa is responsible for the installation and commissioning.