Field Trips 2021

Field Trip April

Friday, April 23
Jakob and David used the good weather to drive to stations to build up more corner reflectors. Thomas and I went to the south of Georgia to visit a rather new cascade of HPP in the area of Shuakhevi. We talked with the responsible engineer at the site and could get (without photos) an idea about this HPP system in comparison to Enguri Dam. Also at this site, the power tunnel had been a real challenge.

Thursday, April 22
We went to Abchasia and we really got a unique opportunity because we went into the steel pipes of the penstock area in which the water runs directly to the turbines. Part of these 40 mm thick tubes had to be repaired. We also met our drillers which currently drilled a borehole close to the penstock… oh I wished I would have had Eduard, the winch and the televiewer at the site. Crossing the border takes a long time, so we came back in the evening with some great views into the technique of a giant powerhouse area.

 

Wednesday, April 21
Again Power Tunnel. We tried to measure more structures from adit 4 northward, but after 300 m we could not go on further because ca. half a meter of silt made us get stuck. Thus we returned to adit 1 to prolongate the part which we had been measuring the week before. This time, most of the lights already had been turned off and no rehabilitation activities were going on. So in the absolutely dark tunnel we had to rely on our flash-lights and we hoped that no one will close the big gate when we are in the tunnel. We spent several hours to measure from km 1 to km 2.1.

Tuesday, April 20
Andreas left for Tbilisi after the final check of the GB-SAR. Jakob and David worked on the Corner-Reflectors and Thomas, Birgit and Georgian colleagues took the opportunity to search one of Fritz Rummes Hydraulic Fracturing Boreholes and piles of rocks at the Khudoni location with the means of a metal detector. However, the tool was too weak to find the borehole and we had to go back without success (but being wet). Our Georgian colleagues want to return with a military version of a metal detector... But geologist Thomas was happy because he could measure some of the structures at the Khudoni location.

 

Monday, April 19
Together with Jakob from the geodetic team we measured the exact geodetic height of the KIT-1 and the piezometer wellbores. Only one of the wellbores has to be measured with triangulation methods because we got only too few satellites to determine the exact position. Because some of the boreholes had been on the lowest level we came very close to the open gates of Enguri dam and could admire the impressive water flow. In the meantime Andreas Schenk fixed together with David Svandadze and Georgian workers the GB-SAR at the warehouse station.

 

Sunday, April 18
Again we went into the Power Tunnel. This time for a distance of ca. 5 km from the entry at adit 5. Inside the power tunnel we checked fractures and spalling. Some of the open construction joints could be at orientations of tensile stresses, which had been calculated by PhD candidate Thomas Niederhuber (Team AGW-TP).

Saturday, April 17
On Saturday we provided a presentation for the company Energony who is doing part of the power tunnel rehabilitation works. Afterwards some of us were lifted via a crane and a cage from the top of the dam to the Jvari Reservoir lake. There we measured some points to follow the Ingirishi fault plane…. And we got up again to the dam top… Andreas Kron started his drone to follow our flight. But even colleagues who did not join the crane tour left the surface. Andreas Schenk installed the GB-SAR on the roof of a house at the warehouse site.
 

Friday, April 16
Trip to Nenskra valley. The teams of IWG and IPF had been checking the bridges in the Enguri and Nenskra-Valley for the possibilities to install instruments to measure the water flow and the sediment load in the rivers. All colleagues were impressed by the fact that one of the bridges had been damaged by a flood 2 years ago. (P1010082). In the afternoon the teams separated and the AGW-TP and Piewak & Partner went on to search for potential drilling sites in the Nenskra-Valley. This is quite difficult because only in a few places the bedrock reaches the surfaces. In most places the pebbles and rocks transported by the river would be critical for drilling and logging. However, the rocks close to the river provided a nice place for the lunch break.

Thursday, April 15
PCR Testing day. In the morning Piewak&Partner and AGW-TP checked for the northern prolongation of the Ingirishi fault. Other colleagues discussed with local builders the forthcoming activities and went shopping (building material).

Wednesday, April 14
The teams at Enguri have been working in the field. The IWG-team was digging at a 10 m high embankment for sediment samples in the centre of the Enguri Valley. At that position the original lake bottom had been crosscut by the river due to the low waterlevel which is required for the Enguri power tunnel rehabilitation works. The colleagues Stephan, Klajdi and Andreas also used a drone which offered some spectacular views. As everybody could imagine the digging at the surface was simple…. But they went down the embankment too. What they could not identify clearly was the remnant boot which they found…may be a lost scientist from an earlier field campaign. IPF built up the GB-SAR at the hotel location and the GIK team checked its equipment to be used in the field the next days. The AGW-TP and Piewak & Partner checked fractures in the power tunnel at adit 1 (close to dam) and adit 2 (Olori Valley) as well as the potential location of the Ingirishi fault in the Olori Valley.

Tuesday, April 13
After having passed the COVID Tests at Munich airport and the night flight, we arrived at around 4:30 a.m. on Tbilisi airport where we picked up cars (Andreas, Andreas, KLajdi, Jakob, Stephan) or got picked-up (Birgit, Thomas) by our Georgian colleagues. In the afternoon we met Mr. Aberle from Energony with whom we discussed the model results of T. Niederhuber for the Power Tunnel. Lateron we had a meeting with Director Joni Chania.