Landslide Area Brienz/Brinzauls

Monitoring of an active landslide area with automatic and manual measurements

Project: 2019 - ..., Brienz/Brinzauls (GR), Switzerland

Client: Canton Grisons, Forestry and natural hazards office

The Brienz landslide in the canton Grisons (CH) has been surveyed and its movements monitored for around 100 years. In recent years, these movements have increased significantly. In places, the slopes above the village of Brienz are sliding at a rate of more than 5 metres per year, which has been confirmed by previous measurements.

In order to record changes in the landslide area in the shortest possible time, the project managers at the Office for Forests and Natural Hazards have been relying on 12 TEDAMOS GNSS measuring systems since mid-July 2019, which were put into operation in three stages. The self-sufficient, solar-powered measuring systems enable the project managers to reliably monitor the movements at the 11 sensor locations in the millimetre range, all year round and regardless of the weather, in relation to a local GNSS reference station, which was installed a few kilometres from the landslide area in a stable zone.

The causes of such landslides usually lie in water-bearing layers in the subsurface. In order to observe the water pressures in these layers, we installed a total of 8 automatic porewater pressure or piezometer sensors in 6 boreholes in spring 2023.

To observe the depths and different velocities and groundwater movements of the slip horizons in the subsurface, Terradata regularly performs manual inclinometer measurements in 6 boreholes to depths of 160 m and has performed flowmeter measurements.

Services

Supply, installation and commissioning of autonomous TEDAMOS GNSS sensors
Supply, installation and commissioning of automatic measuring pore water pressure and piezometer sensors
Automatic monitoring incl. alarming with high-precision 1h, 4h and 24h solutions
Manual inclinometer and flowmeter measurements
Online access to current measured values via web-based customer portal.