Selection of TBM

This blog post is with reference to my previous post related to the lecture series on Design and Selection of TBM and it attempts to summarize the Recommendations for TBM Selection practiced in the following countries:

• Germany, Switzerland, Austria (German speaking countries)
• France
• Japan (only soft ground)
• Norway (only hard rock)
• Italy

Following references are cited in this post:

[1] Chapter 19, "Mechanised Shield Tunnelling, 2nd Edition", Maidl. B et al., Ernst and Sohn Publishers, Berlin, 2011. ISBN 978-3-433-02995-4 (link)

[2] ITA working group on Mechanized Tunnelling, "Recommendations and Guidelins for Tunnel Boring Machines (TBMs)", ITA-AITES, 2000 (link)

[3] AFTES Working Group no. 4, "New Recommendtaions on Choosing Mechanized Tunnelling Techniques", Tunnels et Ouvrages Souterrains, Hors-Serie No. 1, 2005

It should be realized that it is not possible to draw up an analytical method for choosing the most suitable TBM. All the above guidelines just give definition/classification of different types of  TBM, highlights the scope of application and analyses the effect of selection criteria (geological, project, cost, etc.)

German speaking countries mostly follow, DAUB recommendations [4] for the selection of Tunnelling machines and in my opinion, the DAUB recommendations are very comprehensive (which also includes the technical features of the machines). It also summarizes the Rock/Soil parameters which could be used as a thumb rule for the selection of TBM. Following figures shows the classification of TBMs according to DAUB and the general work flow for finalization of Type of TBM. It can be noticed that DAUB's classification system is based on machine type.

Classification of TBMs - DAUB [1]

Flowchart for Selection of TBM

In addition to the above TBMs, DAUB also defines special types of TBM (Blade schields, Multiple circular shield). Terminology used for different machines are dependent on the country of use and hence it should be considered while comparison.

French Tunnelling Association's recommendations (AFTES) [3] have a classification system based on the support type (shown below). In addition to definition of TBM types and applicability, AFTES recommendations have evaluated the effect of different parameters on different type of Tunnelling techniques and is tabulated on a three point scale. This helps the designer to check all the factors affecting a particular choice of TBM.

Classification of TBMs - AFTES [3]

ITA Working Group No. 14 report on Selection of TBM [2] provides comprehensive guidelines and recommendations in the form of four individual reports representing Japan, Norway, Germany, Austria, Switzerland, France and Italy. The Japanese working group's TBM classification is similar to the one in DAUB. In addition to the applicability matrix of different types of TBM for different soil conditions, it also makes a comparison with the Drill & Blast method and gives a basic flowchart for selection of TBM for soft ground (shown below).

Flowchart for Selection of Softground TBM - Japanese WG [2]

Norway has developed guidelines for TBM selection for Hard Rock wherein the prognosis model decides the type of TBM and the tools required to achieve a balance between economy (tools consumption) and progress rate. The document further explains the procedure to calculate cutting rate, progress rate, cutter consumption etc.

In the Italian Working Group report to ITA, along with basic classification and definition of TBMs, emphasis has been given to indicate the type of geotechnical and geological tests needed at different stages of design to select the most appropriate TBM. 

Additional Reference:

[4] Recommendation produced by the working group, "Recommendations for the selection of tunnelling machines", German Tunnelling Committee (DAUB)

[5] “Project Report 1-94, Hard Rock Tunnel Boring”, published by University of Trondheim, The Norwegian University of Science and Technology, NTH Anleggsdrift (link)

[6] Tunnelbohrmaschinen im Hartgestein. Ernst & Sohn, 2001 (link)

[7] Stein, Dietrich. Grabenloser Leitungsbau. John Wiley & Sons, 2003 (link)
[8] British Tunnelling Society Working Group, Specification for Tunnelling, 3rd Edition, Thomas Telford Ltd, ISBN: 9780727734778, March 2010 (link)

Week 12 & 13 Tunnelling & TBM Course: Types of TBM & Selection of TBM

Last 2 weeks of lecture (7th to 16th April, 2014) was mainly focussed to give us an overview of types of TBM and selection of TBM according to the project and geologic requirements.

Along with the theoretical background, to give us a practical understanding of TBM type selection and design, we had the following guest lectures from the Industry:

• Slurry shield TBM by Prof. Markus Thewes, Institute for Tunnelling and Construction Management, Ruhr-University Bochum
• Rock TBMs by Mr. Massimo Concilia, Project Manager, Impresa Pizzarotti & C. S.p.A.
• EPB and Hydro-Shield by Mr. Allesandro Cresdo, Manager, Herrenknecht
• TBM Selection case histories by Mr. Jens Classen, Director of Mechanized Tunnelling, TOTO
• TBM Selection case histories by Gilbert Fontanille, NFM Technologies
• Design of TBM by Maurizio Marchionni, Geodata.

In the next blog post, various guidelines for the selection of TBM and key design aspects of TBM are discussed.

Mr. Allesandro Cresto's Lecture on EPB and Hydro-Shield

Week 11 Tunnelling & TBM Course: EPB Tunnelling Soil Conditioning

Along with general aspects of TBM Types and TBM selection, on 4th April, 2014 we had a guest lecture from Singapore (Mr. Richard Schulkins) to deliver a lecture on the topic of Soil Conditioning for EPB Tunnelling.

EPB Tunnelling has experienced a great increase in the number of applications and it can be considered the most used technology of the mechanised tunneling in urban area [3,7]. In this lecture, Mr. Schulkins discussed the objectives of Soil conditioning in EPB Tunnelling and the procedure for soil conditioning using various additives.

Click here for a basic presentation on Soil Conditioning by Prof. Peila (ITACET lecture presented in Argentina).

Followed by the lecture, we had a chance to see the experimental setup and witness some tests. Tests on characterisation of conditioned soil is limited and only recently some large scale tests using laboratory screw conveyor has been proposed [5] (details of past studies and tests are included in this reference) and Politecnico di Torino has one of such facilities to test the conditioned soil [1,3,7].

Experimental Setup in Politecnico di Torino [3]

There are five established tests for optimizing the conditioned soil (Foam penetration test, Slump test, shearing test, Compressibility test and friction test) however, during this lab demonstration, quality assessment of the conditioned soil were tested using slump cone test and permeability test. More details about the experimental setup and the test to assess the behaviour of conditioned soil is covered in the paper Peila et al (2009) [2]. Following video shows the demonstration in the Department of Structural Engineering, Construction and Geotechnical, Politecnico di Torino, Italy.

Following video shows the permeability test on the conditioned soil with 10m constant water head. The details of the setup and the test results could be studied in the paper Borio et al (2010) [4].

References: 

[1] D. Peila, C. Oggeri, and R. Vinai, “Screw conveyor device for laboratory tests on conditioned soil for EPB tunneling operations,” J. Geotech. Geoenvironmental Eng., vol. 133, no. 12, pp. 1622–1625, 2007.

[2] D. Peila, C. Oggeri, and L. Borio, “Using the slump test to assess the behavior of conditioned soil for EPB tunneling,” Environ. Eng. Geosci., vol. 15, no. 3, pp. 167–174, 2009.

[3] R. Vinai, C. Oggeri, and D. Peila, “Soil conditioning of sand for EPB applications: A laboratory research,” Tunn. Undergr. Sp. Technol., vol. 23, no. 3, pp. 308–317, May 2008.

[4] L. Borio and D. Peila, “Study of the Permeability of Foam Conditioned Soils with Laboratory Tests.,” Am. J. Environ. Sci., vol. 6, no. 4, pp. 365–370, 2010.

[5] L. Borio, D. Peila, C. Oggeri, and S. Pelizza, “Characterization of soil conditioning for mechanized tunnelling .”

[6] Pena. A, “Foam as a soil conditioner in tunnelling : physical and mechanical properties of conditioned sands,” University of Oxford, 2007.

[7] R. Vinai, D. Peila, C. Oggeri, and S. Pelizza, “Laboratory tests for EPB tunnelling soil conditioning,” in Underground Space - the 4th Dimension of Metropolises, 2007, pp. 273–278.

• This lecture was a part of ITACET Training Seminar organised in Politecnico di Torino. 

Week 10 Tunnelling & TBM Course: Mechanized Tunnelling (& ITACET Seminars)

Week 10 (24th March to 28th March '14) Lecture series of Tunnelling and TBM course marks the begining of Module 2 of the course, which is focused on Mechanized Tunnelling using TBM. This week's lecture was also combined with the ITACET Training Seminar which was open for working professionals also.

Week 10's lecture along with Today's (1st April '14) lecture by Professor Peila gives a complete overview of Mechanized Tunnelling using TBM (more details in the links below).

Following lectures were covered during this week:

• 1st April, 2014: General Aspects of TBM by Prof. Daniele Peila, Politecnico di Torino
• 24th March, 2014: Advances in Urban Tunnelling by Dr. Harald Wagner, International Consultant, Thailand
• 25th March, 2014: Urban Tunnelling and Case Studies by Prof. Kalman Kovari, Professor, ETH, Swiss Federal Institute of Technology Zurich
• 26th to 27th March, 2014: Cutting Tools and TBM Excavation Performance by Prof. Nuh Bilgin. Professor, Istanbul Technical University, Turkey.
• 28th March, 2014: Tunnel Face Stability by Prof. Georgios Anagnostou, Professor, ETH, Swiss Federal Institute of Technology Zurich.

ITACET Training Seminar