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News

Mai-Juni 2022

In April, we were invited to attend the final conference of the Damast project, where we could present our project. The colleagues from KIT (Karlsruhe Institute of Technology) work within the area of the Enguri Dam and therefore they are our "neighbours". We have agreed to work together in Svaneti with regard to their follow-up project and try to support each other.
In May and June, the staff of the TU Bergakademie Freiberg categorised 140 km of the road from the Enguri dam up to just before Ushguli with regard to the degree of hazard and the hazard mechanisms. Thus, we have a practicable overview of the individual sections. In some sections we have classified the slopes according to the Q-Slope system. This is a very simple, empirical method for an initial assessment of the stability of rock slopes with no reinforcement and possible adjustments in slope angles.

Böschungsarbeiten Straße von Mestia nach Ushguli

Engineering-geological investigations of slope in the Enguri valley

At two localities with slate slopes, drone flights and terrestrial surveys were carried out by Aero-DCS in order to subsequently generate geometric 3d models. At the same time, the two staff members of the TU Bergakademie Freiberg carried out an engineering geological mapping of these localities.
The results are engineering-geological 3d models that represent the slope geometry and joint sets with which calculations on stability are carried out. In addition to 3d models, geotechnical 2d models are also generated, as they are often sufficient for robust statements. Such 2d models were generated in other road sections, too.
In addition, the engineering-geological 3d models are used for the creation of reinforcement concepts by the company Jähnig as well as for the common planning of the rock monitoring (Aartesys) by EA Systems. This common planning ensures efficient monitoring.

The slopes consist mainly of slate, which is very often so heavily fissured that both the geological terrain work and the installation are sometimes very dangerous. At the moment we expect the installation to take place next July and August and the plan is to install the sensors using platform truck.
In addition to the consolidated slopes, further monitoring by means of pendulum sensors will be installed in the Lendjeri debris flow channel. This will be supplemented by the installation of pore water pressure sensors, the installation of a simple weather station and a camera by HTW Dresden. Debris flows in Lendjeri mainly take place in July and especially in August.
With the above-mentioned components, the relation between rainfall events and the triggering of the debris flows in Lendjeri as well as the processes themselves will be better understood. This also helps to make the statements more reliable by modelling future debris flows and deriving appropriate countermeasures.
We are supported in the installation by the mayor of Mestia and the inhabitants of Lendjeri.

During our stay, we were able to test the Georisk app on site so that the company Dassau Geoinformatik could still make improvements. This mainly concerns the transfer of the reports to our server and the subsequent display in the GIS.

 

November 2021

This month, the final locations of the weather station were decided. For Ushguli, the installation is planned at the school. We want to involve the students in our activities, i.e. explain what we do and give them access to the weather data. The aim is to build on this to create an interest in the topic of natural risks or in science and engineering.
We also determined the way of monitoring for Lendjeri and defined the configuration of the system. To do this, visibility analyses were first carried out in QGIS, as the gateway and the probes need to communicate with each other via radio. This allowed us to narrow down the potentially suitable locations for the gateway. With the radio measurements that have now been carried out, we have determined the most suitable location and agreed this with the mayor in order to ensure a continuous power supply for the gateway.

Straße von Mestia nach Ushguli

Slopes in the Enguri valley

 

We also talked to the mayor about the possibility of building gabions to secure the slopes on site. On the one hand, this would create income opportunities and on the other hand, the debris from the debris flows could be used. We will draw up the technical requirements for this and determine the approximate investment costs, while the Georgian partners will look into possible financing from the Georgian side.
The Ministry of the Environment promised us further technical support. Here, the focus will be on historical weather data and events of mass movements. The aim is to gradually obtain an overview of the spatial distribution and timing of mass movements. In addition, we want to work out the connections between e.g. precipitation and mass movements.
Hydrological analyses and simulations of flood events are also being considered. The concrete analyses will be discussed in the coming weeks.
This knowledge will help us to calibrate the monitoring system with regard to alarms and to gradually classify risk areas and hazard zones from the Mestia road to the lowlands.

 

October 2021

We are preparing the field investigations for November. Here, among other things, we will discuss the creation of safety concepts on selected rock slopes. The weather stations are also to be installed and put into operation in the course of November.

Road from Mestia to Ushguli

Road from Mestia to Ushguli

 

August 2021

During the two-week stay, we discussed the concrete work and study areas with the governors of Upper Swanetia and Mingrelia as well as local mayors. Furthermore, we explained our project to the inhabitants in various villages. They were very grateful and offered us their support.

'Black Channel' (left) and debris flow in Zabeshi (right)

"Black Channel" Zabeshi (left) and debris flow in Lendjeri (right)

After the joint inspection of the first selected localities, surveys and drone flights were carried out. These serve as the basis for generating digital terrain models, which are the prerequisite for calculations and modelling of mass movements. For the calculations, sample material was taken from two debris flows in order to analyse the soil mechanical parameters in the laboratory at the HTW Dresden. Within the framework of the field investigations, it was decided to install a first monitoring and early warning system in Lendjeri in the course of the next six months. Currently, the concrete design of the system is in progress. Furthermore, the points for the installation of the weather stations were determined.

Drone images of debris flow in Lendjeri (left) and Zabeshi (right)

Drone images of debris flow in Lendjeri (left) and Zabeshi (right)