Special Mention In Media (ITACET Newsletter)

I am happy to share with my readers that, this blog was mentioned in the ITACET Foundation's newsletter as "A blog of interest". Thanks for your support and continuous encouragement. I will continue to write and share useful and original content.

The newsletter could be accessed at http://www.itacet.org/Newsletter/NL_detail.php?no_nl=19

PDF Link

Special Mention in ITACET Newsletter - July 2014 

"Tunnelling and TBM" Course at Politecnico di Torino, Italy: Summary

In this post, I intend to summarize about the 2nd Level Specializing Masters / Master of Advanced Studies (MAS) degree program on "Tunnelling and TBM", which I was following at Politecnico di Torino, Italy. Having completed the academic course work (46 out of 60 credits), I am about to begin my thesis work (based on job experience / stage / internship) to complete the remaining 14 credits.

MAS program on "Tunnelling and Tunnel Boring machines" at Politecnico di Torino, Italy is one of the four courses offered worldwide on Tunnelling which is endorsed by International Tunnelling Association (ITA/AITES) and ITACET committee. Three of them (including this) are MAS level / 2nd Master's level  course and one of them is MSc level course (details).

The program at Politecnico di Torino combines university lectures with expert lectures from construction companies, machines producers, design companies and industry professionals to provide the multidisciplinary knowledge. The program has been running for around 18 years, offered once in two years, and has now reached its 9th edition (more details).

In clockwise from top-left corner. Herrenknecht site visit, Prof. Kovari's lecture, Prof. Galler's Lecture, ITACET Board with program participants.

Course Structure

The course contained the following modules. Lectures for each of the modules were delivered by industrial experts along with the university professors.

• Contractual and legislative aspects, work sites management, quality 
• General aspects of mechanized tunneling and Hard Rock TBMs
• Plants and microtunneling
• Rock Mass Characterization, Geo investigations and risk assessment
• Safety and environmental issues of work sites
• Soil mechanized tunneling
• Tunnel design and construction method
• Tunnel supports

All my posts related to the course can be accessed here.

Details about the course content are summarized in the following info-graphics.

Time distribution in the program

Distribution of guest lectures

Background of lecturers during the program

Time allotted for different modules

I would like to thank ITACET Foundation for their financial support to follow this program and their constant encouragement during the course work.

My thanks are due to Prof. Peila, Director of the Master Course for his tireless effort and his constant willingness to receive feedback from the participants of the program for continuos improvement of the course.

Sponsors of this edition of Tunnelling and TBM Program

Sponsors of previous editions of Tunnelling and TBM Program

Tunnelling & TBM Course: Case Studies

Tunnelling practice draws upon experience from similar or comparable projects; the success of new construction is based on these experiences. Success in management largely depends on the ability to draw upon and adapt this experience, learning and lessons of failure as well as success. To make sure we had a global idea of practical difficulties faced in tunnelling projects worldwide and the available technologies to handle them, following case studies were studied during the MAS course work on Tunnelling and TBM.

For some of the projects, I have provided reference to the relevant published articles.

Case Study on Ground Improvement

• Zurich Metro (Weinber Tunnel & Zimmerberg Tunnel), Swiss - Underpinning and Microtunnel (link of paper on its instrumentation)
• Metro Vienna (Niederhofstrasse), Austria - Freezing (link)
• Mannheim Subway, Germany - Freezing (link) [5]
• Quadratsch Tunnel, Austria - Jet Grout Umbrella
• Escherberg Tunnel - Hannover Wuerzburg, Germany - Pipe Roof Umbrella
• Warsaw Metro - Consolidated body using HDD (link)

More details about the above projects can be looked at ITA-AITES World Tunnel Congress 2007's Training Course on Ground Reinforcement (link) and in ITACET's Training material on "Ground Improvement, Pre-Support and Reinforcement" held during World Tunnel Congress 2013.

Case study on Swelling Condition

• Gotthard Base Tunnel - Execution and Swelling case study [1, 2]

Case Studies on Segmental Lining

• Groene Hart Railway Channel Tunnel, Netherlands (Largest TBM in 2001)
• Passante Ferroviario Railway Tunnel, Italy
• Seattle Metro Tunnel, USA
• Wanjiazhai Water Tunnel, China
• Wuhan Road Tunnel, China
• Boston Outfall Tunnel, USA
• Bangkok Metro, Thailand
• WSK-E-Vienna, Sewage Tunnel, Austria

Special Purpose/ Dual Purpose TBMs

• Paris Subway - Lot 35B of the “EOLE” line, France - Slurry + Rock TBM [3]
• Sparvo Tunnel - Special TBM arrangement for gas protection and execution case study [4] 
• Klang Valler MRT, Kuala Lampur Metro - Variable Density TBM (EPB + Mix shield)

Case Study on Soil Conditioning

• Singapore NELP Klang River Crossing, Singapore - Soil Conditioning
• Botlek Tunnel, Netherlands - Soil Conditioning 

Case Study on Ground Water Control

• Vienna Metro (Pottendorfer Strasse), Section U6/1, Austria - Ground water control using deep wells
• Munich Metro - Ground water control using Vacuum and Compressed Air
• Bucarest Metro - Dewatering and managing related risks

Case Studies on Numerical Modelling

• Gibraltar Strait Tunnel - Feasibility Design
• Sigma 2, Athens Metro, Greece - Portal Design
• T3 Sochi Portal, Russia - Portal Design
• Maldonado Flood Control Tunnel, Buenos Aires, Argentina - Shaft Design
• Brooklyn Station (Line 5), Sao Paulo Metro - Shaft Design
• Canoas Waterwater Plant (Cribado-Y-Succion) - Shaft Design

Case Study on Slurry Shield TBM

• Wasterschelde Tunnel, The Netherlands
• Lake Mead, USA [11-12]

Case Study on Mix Shield TBM

• SMART Tunnel, Kuala Lumpur, Malaysia [3]

Case Studies on Inclined Tunnels / Shafts

• St. Petersburg Tunnel - Escalator shaft, 30 degrees inclined
• Limmern Tunnel - Incline Shaft using Gripper TBM, 40 degrees inclined

Case Study on Monitoring and Interpreting TBM Output data

• Sao Paulo Metro [3] 

General Project Overview Case Studies

• Ceneri Base Tunnel, Switzerland [8, 9] (Site visit details)
• Lyon - Turin High Speed Railway Tunnel, France & Italy
• Turin Metro, Italy
• Maldonado Flood Control Tunnel, Buenos Aires, Argentina
• Metro de Porto, Portugal [3, 6] 
• Jerusalem (HSR T3) High Speed Railway, Israel

Overall, around 50 tunnelling projects were discussed regarding various aspects of the projects to give us a link between 'Theory to Design to Practice' and to understand the state of the art industrial practices.

References:

[1] Heinz Ehrbar, Gotthard Base Tunnel Sedrun section mastering squeezing rock zones, Underground Space Use: Analysis of the Past and Lessons for the Future – Erdem & Solak (eds) © 2005 Taylor & Francis Group, London, ISBN 04 1537 452 9

[2] Kovári, Kalman. "Design methods with yielding support in squeezing and swelling rocks." World Tunnel Congress, Budapest, Hungary. 2009.

[3] Guglielmetti, Vittorio, et al., eds. Mechanized tunnelling in urban areas: design methodology and construction control. CRC Press, 2008.

[4] GATTI, Martino, Rocksoil SpA, and Giovanna CASSANI. "The largest TBM–EPB machine in the world, designed to the Appennines. The experience of the Sparvo Tunnel."

[5] Stephan Semprich: Ground freezing technique with respect to tunnelling in urban areas.

[6] Babendererde, Siegmund, et al. "Geological risk in the use of TBMs in heterogeneous rock masses-The case of “Metro do Porto” and the measures adopted." Workshop in Aveiro, Portugal (in print). 2004.

[7] Volkmann G.M., Button E.A. & Schubert W. 2006; "A Contribution to the Design of Tunnels Supported by a Pipe Roof." Proc. 41st U.S. Rock Mechanics Symp., American Rock Mech. Assoc., June 17-21, Golden, CO.

[8] Filippino, R., K. Kovari, and F. Rossi. Construction of a cavern under an autobahn embankment for the Ceneri Base Tunnel." Geomechanics and Tunneling 5.2 (2012).

[9] Anagnostou, Georg, and Heinz Ehrbar. Tunnelling Switzerland. vdf Hochschulverlag AG, 2013.

[10] Galler, R., et al. "The New Guideline NATM–The Austrian Practice of Conventional Tunnelling." BHM Berg-und Hüttenmännische Monatshefte 154.10 (2009): 441-449.

[11] Feroz, M., Jensen, M. & Lindell, J.E. 2007. The Lake Mead intake 3 water tunnel and pumping station, Las Vegas, Nevada, USA. RETC Proceedings, 647 - 662.

[12] Georgios Anagnostou, Muir Wood Lecture 2014 "Some Critical Aspects Of Subaqueous Tunnelling" (link)

Ceneri Base Tunnel Visit - Week 24

During the Week 24 (30th June - 4th July) of our Tunnelling course, we had a visit to the Herrenknecht HQ and a visit to the Switzerland's third largest tunnel - Ceneri Base Tunnel. This blog post presents some of the details of the latter.

Ceneri Base Tunnel © AlpTransit Gotthard Ltd. Retrieved 4th July '14

The 15.4 km Ceneri Base Tunnel completes the link between Zurich and Milan (passing through the Gotthard Base Tunnel) with overburden varying from 800m to 100m. The project is managed by Alptransit Gotthard Ltd and the contractor is Condotte Cossi Consortium.

Location of Ceneri Base Tunnel [1]

Based on the Pini Swiss Engineer's presentation (during Week 18 of our course), we had an overview of the project's technical and geological challenges. Our visit was more focussed to learn the operational and logistical challenges and how innovatively, the Alptransit has been managing it. This tunnel construction site, probably, has the most mechanized form of Drill and Blast tunnelling.

The tunnel face

The tunnel face can be seen in the picture above. There is no problem in the stability of face and hence no additional measures are taken. The support system can be seen - rockbolts with shotcrete. No steel arches are used. Second layer of shotcreting is done after installing the rockbolts.

Three boom drilling jumbo (suspended logistic platform can be seen at crown)

Crusher at the starting of belt conveyor.

The tunnel is excavated using Drill and Blast technique. Two drilling jumbos are available at the site. One of them is used for tunnel advancing and the other one is used for cross tunnels. After each round of blasting, the muck is loaded in to the crusher using a back hoe loader. The crusher is connected to the belt conveyor and the muck is taken away to the portal. The whole system of belt conveyor and ventilation is hanging from the crown using a logistic platform and could be extended as the tunnel advances (like in a TBM).

One of its kind - Concrete batching plant inside the tunnel (special cavern)

Special cavern is built to accommodate the batching plant inside the tunnel itself.

Provision for future expansion

Complete muck handling system is using belt conveyor.

Nonel detonators

Sliding form work for Tunnel side walls in preparation

Sliding formwork for the tunnel side wall can be seen in the above picture. This is at a cavern location. The complete crown is going to be concreted using shotcrete (no formwork is used at cavern's crown). Lattice girder type assembly is used in steel cage work to optimise the rebar cage assembly time.

References:
[1] European International Contractors (EIC) newsletter (link), retrieved on July 5th, 2014.

Herrenknecht Visit - Schwanau, Germany

Towards the end of our MAS degree program on Tunnelling and TBM at Politecnico di Torino, we had an opportunity to visit the Herrenknecht's main manufacturing facility in Schwanau, Germany. Politecnico di Torino (Prof. Daniele Peila) along with the Herrenknecht's engineers organised this visit for the participants of the MAS program.

Herrenknecht EPB TBM for Doha Metro - Assembled at Schwanau, Germany

I have been working as a Geotechnical engineer from the year 2009 and during this period of 5 years, I was lucky enough to visit and get involved in some very interesting construction sites (ranging from mining sites, underground metro, harbour facilities, skyscrapers, power plants, railways etc) but I was never as much excited as I was during the visit to the Herrenknecht's headquarters. Although this is technically not a construction site, the Tunnel Boring Machines (TBMs), manufactured here, plays a pivotal role in the success of any Tunnelling construction site and the amount of "Civil engineering concepts" goes into making of this "Mechanical machine" is immense. It was not just me, most of the course participants felt the same way. It was the Disney Land of the Tunnel/Geotech engineer or of that sort, one can not get upset here.

We had an opportunity to visit EPB TBM, Mix-Shield (Slurry) TBM, EPB-Hard Rock Convertible TBM and Hard Rock Gripper TBM in the bigger diameters suite. In addition to the assembled TBMs, we witnessed and learned, among others, the following important aspects:

• The process of assembly of main bearing
• Segment erection process
• Mechanism of foam delivery for soil conditioning
• Working of screw conveyor
• Slurry separation unit

On the Microtunnelling front, we saw completely assembled and spare parts of Pipe jacking Micro TBMs (EPB and Slurry), Pipe thrusters and HDD rig. This visit, coming just after Prof. Sterling's lecture on Microtunnelling gave us a comprehensive understanding on the mechanism of Microtunnels and working phenomenon.

Herrenknecht - Main facility entrance