To abroad excursion
Every two years the Geotechnical and Rock Engineers’ club organizes a big excursion abroad. The purpose of the trip is to familiarize the club’s members with geotechnical and rock engineering in countries other than Finland and also show them what kind of work finnish companies do abroad. It has already been two years since the last trip and the planning of this years excursion has begun. Because of the 2017 excursion to South Korea the expectations are high and we are determined to organize just as interesting trip also this year. This fall the club’s members get to explore geotechnical and rock engineering in Central Europe. During our trip we will visit the most fascinating construction sites and consulting offices in Southern Germany, Switzerland and Austria. Our destinations are particularly interesting because there are numerous tunnel and railway construction sites. There are for example many tunnel boring machines used under the Alps at this very moment. Many finnish companies are also operating in these countries and it is not impossible that some of our club’s members will be working there in the future. These are just some of the reasons why it is crucial for future professionals to broaden their skills.
You can get more information about our trip by following this page and our clubs social media or by asking from the organizing group.
+358 40 418 3088
+358 40 570 5701
The whole excursion group arrived on time to the Helsinki-Vantaa airport at 6:30. Thanks to the early flight to Stuttgart, we landed before the noon and had the whole day to explore the city. One of our group member, Ossi, had an idea to go see the Urach Waterfall. So we took both the rental cars and left for a evening trip. There were some difficulties to find the place, we couldn’t drive all the way there. Cars were left and the long walk began. Finally we made it there and it was worth the walk.
Our second day of the excursion started with a first site visit, Züblin’s site in the city, Stuttgart 21.
The Deutsche Bahn’s Stuttgart 21 is a rail project part of the European Paris-Stuttgart-Bratislavia railway axis. An estimated 10 billion euros has been spent on the project so far and the estimated completion time was 2021.
The main railway station comprises of Northern, central and southern section. The project runs across the Stuttgart valley which has a complicated geology. The valley crossing has a lot of conflicts with sewers, tunnels and other underground infrastructures which would be relocated. Also, the project is in conflict with the mineral water reserve, which is the second largest in Europe and according to German regulation, the water flow can not be stopped. The project, being in the central area of the city, has to be planned in a way not to disrupt traffic. One of the major challenge with the project site is a 100 year old building, which was underpinned and raised in order for tunnels to be built underneath.
One of the most interesting topic was about the chalice shaped segment columns which would be used to construct the main railway station. A total of 28 chalice shaped segment columns is to be constructed. The chalice shaped column being a complicated structure has to be constructed in 3 phases. It is really fascinating how each rebar and pre-stressed concrete has to be designed for each 28 columns. It took 9 months to complete the first column due to its complexity. This was a great learning point for the group. Questions about settlements of the columns were asked as they would be constructed at different time frames. Settlements of the columns are estimated at 2cm, which is negligible compared to the size of the columns.
The third day of our excursion started with a drive to Rastatt where Zublin AG presented us the Rastatt railway tunnel. The tunnel is part of the new Karlsruhe-Basel railway being constructed. Our focus was of course on the two TBMs used at the site, since none of the group had seen one before. TBMs were used to excavate two over 4-kilometer tunnels below the city of Rastatt.
First, in a project presentation, details of the project were discussed. Challenges of the project were clear. Low overburden, difficult groundwater and overground conditions to mention few. Some solutions were based on the TBM itself which used bentonite slurry to counter the earth pressure. Another interesting solution was to use freezing to reduce effects to the groundwater and provide support.
After the presentation was a visit to the tunnel. We drove a train used to operate the logistics of the TBM to the tunnel face. Luckily for us, the TBM was in parked position which allowed us to visit also the areas right behind the cutting head. We even got a small demo of the ring element ejector in use.
One of the absolute highlights of our excursion was the visit to Herrenknecht factory in the afternoon. We were given a detailed presentation of the company and their products in addition to the principles of the different TMB solutions. The visit was topped off with the tour of the factory. Thank you for Zublin AG and Herrenknecht AG for great excursions.
On Wednesday, after the first and only night in Zürich, our excursion group woke up early for visiting the head office of Pöyry Switzerland Ltd. There Hans-Martin Braun warmly welcomed us and gave an interesting presentation including the history of Pöyry in Switzerland, overview of the competences and fields of expertise of the company as well as information of the past projects related to geotechnics and underground construction.
Braun told us that Pöyry’s main competence in Switzerland consists of transportation & technics, civil & structural engineering and water & environmental engineering. 600 experts working in six offices have been involved for example in designing and consulting over 1000 km of tunnels in the past 20 years. Switzerland’s annual investment in infrastructure is as high as 60 billion CHF (~60 billion €) which takes care that Pöyry’s expertise is highly needed today and in the future.
The expertise of Pöyry Switzerland is not limited to home country projects. For example one of the export consulting projects Braun told us was Tunel Emisor Oriente, where 62 km wastewater drainage tunnel from Mexico City to Hidalgo was constructed using six TBMs. Other reference projects that Braun highlighted were Gothard base tunnel, Nant De Drance pump-storage scheme and Zürich Cross-city rail link. We heard a lot of interesting technical details about these projects. Probably most of the questions excursion group made for our host was concerning the Gothard base tunnel project. We learned of its geological conditions, post-excavation convergence issues and steel ring support techniques, just to mention a few.
After the Pöyry’s office excursion our group hopped on to the two minibuses and we drove 200 km to Albula tunnel II construction site, which is one of the ongoing projects of Pöyry. The site is located in the altitude of 1820 meters above sea level in the small town called Preda. The drive itself to the destination was an unforgettable experience because of the spectacular scenery of Alps!
In Preda, our host Patric Walter, the site manager of Albula tunnel II, gave us a presentation of the tunnel project. The existing 6 km long Albula railway tunnel, constructed in 1903 and being nowadays a UNESCO world heritage, had become to the end of its life cycle. It was then decided that new Albula tunnel II will be built next to the existing one, making the old tunnel to serve as a service and emergency tunnel.
The drill & blast based excavation of the Albula tunnel II is already finished while the other tunnel interior construction phases, including for example the permanent supporting and dismantling drainage systems, are ongoing. After the comprehensive presentation of the project, Walter guided us to the site. The site excursion consisted of the visit to the tunnel itself as well as seeing the gravel production site and the temporary wastewater treatment system of the tunnel.
After the site visit, the group of ours greeted our host for fascinating excursion and started the trip to our next accommodation in the town of Chur. Once again, thank you Pöyry and our hosts Hans-Martin Braun and Patric Walter!
After waking up in Chur we began the drive to our excursion of the day. We headed to Hagerbach Test Gallery, which is a tunnel where companies have a chance to test and develop for example their construction techniques. Our visit started with a introduction of Normet, which is one of the over 20 companies that are using the tunnel for their purposes. Normet is a manufacturer of machines mainly used in mining and tunnelling. What really captured my interest was their new electric SmartDrive machines and how they are all electric. Also their future goal is to have the machines fully automatic so that they can do the work by itselves. After the Normet’s presentation there was a short introduction to the Hagerbach and after that they took us to a tour around the tunnel. Some of the things they do in the tunnels were pretty interesting. For example they have a section where firefighters have been training putting out fires and evacuating.
They also have a rock and concrete testing laboratory and in addition to so called serious work they organize underground weddings, raves etc. You can find a firing range from there too. The final part of the excursion was a lunch at the restaurant in the tunnel. Thank you Normet for the food! It was delicious! Rest of the day we spent driving to Innsbruck and exploring the city which from the first glance felt really charming.
Friday started with a tasty breakfast after which we started heading towards today’s excursion site – Brenner Base Tunnel (BBT). Car trip from Innbruck took 45 minutes of curvy roads with breathtaking views.
BBT is a new railway tunnel from Austria to Italy.
We arrived to LOT H51 Pfons-Brenner which is a large section of BBT located near Italian border. BBT has two single-tube main tunnels, exploration/evacuation tunnel, cross sections in every 333 meters and emergency stations in every 20 kilometers.
The large majority of the rock excavation is done with TBM’s. In cross sections and in some more difficult places Drilling and Blasting is used. Once complete, BBT will be the longest railway tunnel in the world with the length of 55 kilometers. Total length of the tunnels will be overwhelming 230 kilometers.
Working with two countries’ authorities and regulations had been a challenging task. Traditional tunneling methods are different in each country which demanded adjusting plans to please both authorities. Austrians are used to New-Austrian-Tunneling-Method (NATM) whereas Italians use ADECO-RS (Analysis of Controlled Deformations in Rock and Soils) method. Originally exploration tunnel was meant to be used to gather information for tender phase but getting over 5000 permits in both countries resulted delay from the very beginning. Thus, excavation of the main tunnels had to be started before exploration tunnel was ready.
Long tunnel brings also other challenges like where to put all the excavated rock mass that was over 7 million cubic-meters in just lot H51 section that we visited. For this purpose project rented a whole valley to be used as a landfill. Level of the ground surface will rise around 150 meters for distance of over 500 meters. Current stage of the construction can be estimated from the volume of excavated rock. There is still some work to be done. Current estimate for the whole tunnel to be finished and operational was 2028.
After the interesting tour we headed back to Innsbruck to enjoy some food and free time.
Saturday was a chill day for us. First we went to Starkenberger’s brewery where we tasted local beer and also we got familiar with traditional German style of making pilsner and lager. After few beer we headed up to the Aqua Dome spa. Spa was really nice, like the ones in Baden-Baden. After 2 hours of swimming and relaxing, we drove back to the hostel where some of us continued the evening at the city and rest of us went to sleep. What a good day in Innsbruck.
On Sunday morning, Day 7, everyone woke up on their on time since we didn’t have any plans early in the morning. The were two good options for passing time before continuing our trip to Munich: One car drove up to the Hafelekar mountain to see the spectacular view over the city, the other car went to another mountain to see a beautiful mountain farm and to drive down the hill by unmotorized carts. Afterwards both cars continued their way to Munich. After arriving to the hotel and check-in we went to hang out with fellow engineering students from Technical university of munchen (TUM). A student representative showed us around in the campus and also served us a traditional bavarian dinner in their association room, which of course included some local beer. Everyone enjoyed the night very much and we got to share the study and some professional experience with local students. It seems so that their system is after all very similar to ours.
On monday morning we had an excursion in TUM’s geotechnical laboratory. On our way to the laboratory with got to experience a big city traffic jam. Fortunately we reserved enough time for the transportation and got there on time. The laboratory host was very kind person and ethusiastic in explaining us not only what they do but also why is their work important for the society. We learned that constant researsh is imperative for coming up with smarter and more cost-effective solutions in geotechnical operations.
After the excursion, we had the rest of the day free, so everyone had an opportunity to explore the city and enjoy sunny weather.
In the last excursion day we visited the Bauer manufacturing plant. The plant was located in Aresing city a 40 min driving distance from Munich. Christine, from Student Council for Civil, Environmental and Geoengineering, joined us for the excursion. We met her on Sunday when we were visiting their place in the campus. On the way to the destination we saw authentic views of German countryside.
Bauer group is a leading provider of services, equipment and products related to ground and groundwater. Bauer group is divided into three segments: Construction, Equipment and Resources. Bauer’s manufacturing plant in the Arusing was focused on assembling rotary drilling machines and cutters and it was under the Equipment segment.
In the factory area there was presented different production stages which they are doing in Aresing. We got nice overall figure what is done there and we could see a wide range of different rotary drilling digs and cutters. It was interesting to learn about the technologies inside those machines. For example, the amount of hydraulic equipment inside those machines is impressive. There can be 1000 liters of hydraulic oil in bigger machines.
Afternoon we spent exploring the city. We went to discover the city centrum, enjoyed good weather and hanged out with local students. All in all, the last full day of the trip was exiting. It was very interesting to see machines that usually doesn’t exist in Finland. Many thanks to Bauer group for today’s excursion! Thank you our hosts!