T&TBMs MAS Course Final Trip

Day 1 (06/07/16):

During the last week we had the opportunity to visit some very interesting sites as a conclusion of the course.

To start with, we went to the hydroelectric power plant of Nant de Drance in Switzerland. In this site, an enlargement of the system was done in order to double the capacity of an upstream dam. In this way, by a pumping station is possible to save the energy with an efficiency of 85% in the surplus moments. The final capacity of the power plant will be 9000 MW. For the twin tube connection to the pumping station an open TBM was used with several ground treatment operations in order to cross a fault zone with water pressure up to 20 bar and with high risk of causing settlements to the arch dam. For the twin vertical shafts of 8 m dia. the raiseborer technique was utilised to drive a pilot tunnel from which the D&B muck could be removed from the bottom caverns. Steel lining was required in the most critical components of the tubing system with the highest requirements for the welding and junction systems. A very unique and impressive solution was construction of massive underground caverns for the installation of a batching plant and mechanical offices. A unique project with the highest standards and a very positive scope in one of the most beautiful alpine environment.

Students at Nant de Drance hydroelectric power plant with the extended dam at the back.

Day 2 (07/07/16):

During the next day we had the fantastic oportunity to visit Herrenknecht factory in Schwanau, Germany. The leader of the market is producing their machines in a taylor made and precise way, providing solutions for most of the underground excavation techniques and scenarios. We visited the microtunnelling and mining areas and then the TBMs section where the machines of the upcoming projects are being built. There were several EPBs, Mixshields and Rock TBMs in different phases of assembly and production. The possibility to see the separate components and study them in detail it is fundamental to understand its working principles and functioning. One of the most impressive experiences for a young tunneler, walking through this small town producing such powerfull and reliable tools. In the picture, a 15,7m dia. Mixshield TBM being assembled.

Students at Herrenknecht factory in Schwanau, Germany.

Day 3 (08/07/16):

To close the trip we went to northern Italy, in the border with Austria to visit the jobsite for the future Brenner Base Tunnel (BBT). The exploration phase was just finished on the italian side by driving an open rock TBM through the future emergency escape tube, that will be used in the future for the muck out of the excavated material up to the deposit area to reduce the impact on local roadways. The project consist of twin tubes for a high speed railway connection taking part of the South - North corridor from Naples to Helsinki. The construction should start by the end of this year as the tender is being closed at the moment. After receiving a presentation on the main features and challenges of this project by the client’s engineering company we went to visit the stretch finished as well as the underground TBMs assembly cavern in the core of the alps. Great attention is being paid in this project to the communication with the local people, by informing and giving access in order to reduce the opposition to such a possitive project for the enviroment and the community.

Underground TBMs assembly cavern for the Italian lot of the BBT.

Week 24: Jobsites organisation and Microtunnelling

During the last week of the Master course, Nicola della Valle (Tunnel Consult) held a very interesting lecture on the logistics and organisation of job sites in urban areas where the efficient use of the available spaces is a key for the tunnel excavation productivity. He presented some case studies from his vast professional experience of well and not so well organised job sites and the direct consequences in the overall quality of the tunnelling process.

Nicola della Valle and the students of the master after his lecture on Jobsites in Urban area

Going on during this week, Roberto Crova presented the case study of Torino Metro Line 1 Extension, a jobsite that we had the opportunity to visit during the last day of the course, where the space available was minimum to launch the machine in a telescopic way with the back up completely installed at the surface.

Cutterhead of the EPB machine to be used for the extension of Torino Metro line 1

Mario Patrucco from Politecnico di Torino held a fantastic lecture on safety in underground spaces, risk management and ventilation design. This was part of a five days module fully dedicated to the safety control.

Finally to close with the Master Course, Ray Sterling from Louisiana Tech University held a fantastic intensive course of three days concentrated on Microtunnelling and trenchless excavation techniques. 

Week 23: Ventilation and Safety in underground spaces II

Elena Chiriotti Tender management

Elena Chiriotti and the students after her lecture on tenders management

This week was devoted to the study of the the safety and ventilation issues by
Achille Sorlini of Telt

Achille Sorlini and the students after his lecture on safety on work sites

and by Prof. Mario Patrucco of Politecnico di Torino
Finally Prof Romano Borchiellini of Politecnico di Torino  gave a good analysis of the design issues of tunnel ventilation

Week 22: Safety in underground spaces I

This week Prof. Patrucco started the analysis of the safety issues in tunnel construction.
The topic of  use of compressed air in Tunnelling was developed by Eng. Paolo Morzone and Eng. Luca Bicchierini of Atlas Copco company

Prof. Marina Pirulli of Politecnico di Torino  developed the topic  of tunnel vs slope stability

The important case history of the Frejus tunnel was discussed by Eng. Leone of Telt

Week 21: TBM's auxiliary systems

Starting with this week, Patrizio Torta (PM&E) presented some case studies of Claims, focusing on the importance of the rights and duties of each party acting on a project. He emphasised as well on the value of a well established contract to avoid conflicts and its catastrophic consequences in economical and schedule terms.

Patrizio Torta and the students after his lecture on claims management

Fritz Grübl (PSP Consulting Engineers GmbH and University of Applied Sciences Stuttgart) held a very interesting and dynamic lecture on TBM driving and segmental lining design. As a founder member of TACS guidance systems he discussed the evolution and state of the art of this key component of the machine for its precise steering along the designed alignment. His main research topic at Stuttgart University of Applied Sciences is Segmental Lining so he presented as well the most important aspects for its design and installation. 

Fritz Grübl and the students after his lecture regarding TBM guidance and lining

From his more than 30 years experience on TBM drives, Antonio Nicola from Salini Impregilo   pointed some very interesting and crucial aspects to take into consideration for the planning and operation phases of a mechanised tunnelling project. Focusing mainly on the auxiliary and miscellaneous systems such as:

• Muck transport
• Concrete and segments transport
• Ventilation system
• Hyperbaric facilities
• Slurry treatment plant
• EPB soil conditioning agents supply
• Dewatering and water treatment plant
• Compressed air supply
• Electricity supply

Antonio Nicola and the students after his lecture on TBM miscellaneous systems

Jarre Pietro (Global) gave us another of his peculiar presentations focusing on the importance of a well established communication and the increasing importance of the GIS and BIM based softwares to improve the interoperability of the parties involved in the design and construction process. Technology provide us with powerful tools that must be exploited to enhance the logistics, monitoring and communication during the life span of a project.

Pietro Jarre and the students after his lecture on GIS and BIM use for communication.

Week 20: Frejus Exploratory Tunnel jobsite visit

Starting with this week, Romano Allione (FIDIC Contracts expert) started with a two day seminar to explain the main concepts behind conditions of contracts of the International Federation of Consulting Engineers guidelines (Red, Silver, Yellow book). He took some time as well to present some very interesting case histories from his wide personal professional experience, such as Panama Canal where he provided his expertise.

Romano Allione and the students after his lecture on FIDIC conditions of contracts.

During this week we had the opportunity to visite the Frejus Exploratory Tunnel from the french side, we visited the segmental lining factory and the underground cavern for the assembly of a NFM single shield rock TBM. Some additional pictures are available at Site Visit section.

Course members and Master's director Daniele Peila at the jobsite entrance.

TBM's Cutterhead and Shield inside the underground assembly cavern.

Finally during this short week due to the Republic Day of Italy, Oggeri Claudio presented a very interesting lecture on the reuse of excavated material. This is a topic of mayor concern nowadays due to the higher constraints in terms of disposal of the spoil, the possibility of reutilise it instead of treating it as a by product has to be considered not only for environmental but also for economical reasons.

Frejus Exploratory tunnel site visit

Site visit to Frejus Exploratory tunnel:

40 ton crane at the main portal of the jobsite.

Segment Factory:

Segment mould with anchored gaskets installed and oiled.

Concrete casting of the key segment.

Connector socket and spacer for the reinforcement.

Forklifts for the segments handling.

Anchored gasket installation on the mould.

Longitudinal joint of the segment with guiding rod.

Invert precast segments.

Segments stockage area.

Underground TBM assembly cavern:

TBM's shield and cutterhead during assembly. 

Lifting device for the assembly of the TBM's shield components.

Overhead crane for the assembly of the backup.

Main bearing of the TBM.

Launching pit of the TBM.

Week 19: Some remarkable case histories

During this week we had the opportunity to gather some of the most interesting case studies of the carrier of Brian Fulcher (Ex Kenny Construction Company, USA). He introduced cases such as metro line extension in 72nd street NY and Rio Piedras in Puerto Rico, explaining the keys of the successes and defeats he faced during this challenging projects.

Brian Fulcher and the students after his lecture.

Going on this week, Berenice Moreau (CETU, France) held an outstanding lecture on segmental lining design for fire resistance. Starting from the analysis of the catastrophic fire events that took place in the late nineties all around europe, she went through the evolution of the laws and norms concerning the lining design to introduce the theories proposed and in use nowadays in order to bring safety inside the tunnel not only in terms of stability but mainly for the people passing through. 

Berenice Moreau and the students after her lecture.

Daniele Martinelli (Politecnico di Torino) presented a great lecture on abrasivity tests to be carried out in the laboratory for the assessment of the wear phenomenon of the tools during the excavation process. Even if there are some standard tests very well known and correlated to the cutting tools life, there is also a great research on going to find tests that are more and more representative of the true conditions to be found on site.

Some representers of Pini swiss engineers came to present the project of Ceneri Base Tunnel they worked on as designers in the last years. Davide Merlini as the chief manager of the project, presented its main aspects and peculiarities. Stefano Morandi talked about the geological features as the Site Supervisor in Sigerino adit. Mateo Falanesca presented the approach adopted for the design of rock excavation and finally Francesco Rossi explained the case of a portal through filling material below a highway under operation, a masterpiece of engineering.

Pini Engineers and the students after the lecture.

Finally, Giovanni Giacomin (Ghella Mechanised Excavation Manager) presented two great case histories. Starting from Maldonado sewage system in Argentina, a two tube system to cope with the constant floods of Buenos Aires city with a pumping station to the sea. Then he presented a fantastic project developed in Australia for the Brisbane Legacy Way, an outstanding performance in terms of quality security and logistics.

Giovanni Giacomin, his son and the students after his lecture.

Week 18: Visit to TUSC laboratory

To start with this 18th week of the T&TBMs MAS Course, Gustavo Bomben from FAVA company held a great lecture presenting their products, the technology and research behind them. The main focus was Gaskets and Connectors for segmental lining, they are pioneers in the market developing precise and smart solutions to guarantee a watertight and durable lining system.

Gustavo Bomben's lecture on Gaskets and Connectors for segmental lining

Later on, we went to Politecnico di Torino TUSC (Tunnelling and Underground Space Center) Laboratory where Daniele Martinelli and Cristina Oñate Salazar (PhD TUSC researchers) carried on some of the most common tests on soil conditioning to asses the proper dosage. As the tests used for this purpose are varied and come from other industries (concrete mainly), the ability of the operators and experience in the use of the conditioning agents is the key to obtain a proper conditioning of the soils.

Daniele Martinelli, Cristina Oñate Salazar and the students in the TUSC laboratory.

Marco Arato from Atlas Copco presented a complete lecture on mucking systems for mining and tunnelling. He went thoroughly through the main features of their available systems for the handling and transport of the excavated material. LHD (Load Haul Dump) vehicles and train systems are their most developed spoiling techniques.

Marco Arato's lecture on muck transport systems.

Week 17: TBM complementary facilities

Tommaso Grosso from Astaldi presented a set of case histories emphasising mainly on his last project at Warsaw metro. He described thoroughly the organisation of the jobsite in the urban area where space is very limited and the logistics are of main importance to avoid interferences and increase the productivity of the excavation process. Special attention was paid to the TBM assembly, launching, station crossing and arrival of the machine, that require tailor-made engineered solutions as these are critical processes.

Eng. Tommaso Grosso and the students after his great lecture.

Professor Daniele Peila presented the technology and design methodology of Conveyor belts for muck transport in TBM driven tunnels. He based his lecture on a recent real case for a 7 km tunnel below the Alps. Designing every component of the system for the peak production expected is a must in order to avoid advancement limitations. This is a complex system that enhance the mucking out processes for medium to long tunnels reducing interference with the jobs and the risk of accidents due to vehicle impact to workers that is the main source of injuries for all projects.

During this week we had also the presence of Michele Mangione (ARUP) talking about segmental lining design and some very interesting case histories from his worldwide experience. His dynamic approach was the key to merge his knowledge with our interests in topics such as cross passages construction.

Michele Mangione and the students after his lecture.

A fantastic lecture was given by Richard Schulkins (MAPEI) regarding soil conditioning and backfilling grouting. His great experience in job sites all around the world was clear from his practical approach to treat topics that should not be tackled theoretically but from the continuous analysis of the conditions in the machine during the advancement. Each of these topics should never be disregarded as even if they may seem complementary, they play a paramount role on a smooth and efficient excavation process.

Richard Schulkins and the students after his lecture.

Week 16: Hard Rock TBMs

This week was fully dedicated to Hard Rock TBMs and some site organisation concepts concerning the miscellaneous systems to be taken into consideration for a mechanised tunnelling jobsite.

Mr. Brian Khalighi (Robbins, Engineering Vice President), held a fantastic lecture on Hard Rock TBMs coming from one of the most pioneering companies in the field. He went through the evolution of the technology applied to excavate this type of ground from the days of the foundation of the Robbins company until the last case studies in the most challenging conditions. He introduced as well the main features of Open Shield, Single Shield and Double Shield Machines, treating paramount aspects such as:

• performance, 
• cutterhead and cutting tools,
• ground improvement,
• backup systems,
• muck removal and 
• long distance tunnels considerations.

Brian Khalighi and the students after his lecture on Hard rock TBMs

To close with this week Dr. Massimo Concilia (Pizzarotti), held a very interesting two day course on how to choose or adapt already owned TBMs for Hard Rock conditions from his wide experience in the construction field of mechanised tunnelling. Based on some key cases he pointed out the most important factors to be considered while driving TBM tunnels and remarked the importance of a tailor-made precise solution to avoid some of the worst consequences to happen during the project. In addition he discussed about the jobsite planning and organisation in terms of logistics to enhance the productivity and reduce as much as possible the interferences and downtimes.

Excerpt from Massimo Concilia lecture on Hard Rock TBMs design

Week 15: Numerical Modelling and Monitoring of TBMs Advancement

This week in T&TBMs Master was devoted to the study of TBM advancement with lessons held by experts coming one more time from Geodata Engineering S.p.A. First some simplified 2D numerical models were defined to simulate a TBM driven tunnel behaviour and then we analysed as well the real parameters obtained from the machine driving and monitoring system.

Once again, Vincenza Floria (Geodata) gave us a two day practical course on FLAC 8.0 to model the advancement of the machine. The approach adopted for the simulation was the application of a relaxation factor known as the stress reduction method by Panet and Guenot (1982), in order to allow some gradual convergence of the excavated section before the installation of the lining. An interesting task required to perform a parametric analysis to understand and verify the influence of some factors as ground or lining properties and natural state of stress on the model behaviour. From this basic use of the software I could understand that it is a very powerful tool that requires a deep knowledge of the governing background theories.

Excerpt of a parametric analysis exercise done with FLAC 8.0

Finally Giampiero Carrieri (Geodata) held an outstanding lecture on TBM monitoring, not only regarding the machine driving parameters but also of the interaction between the excavation and the already existing structures. He focused on the importance of a well defined monitoring plan to take into consideration as a key tool for the Risk Management Plan, properly defining thresholds and countermeasures to be taken. His approach for the introduction of the topic was based on the presentation of several case histories from his most relevant projects.

Giampiero Carrieri and the students after his lecture on TBM Monitoring

Week 14: Facing Geological Particularities with Closed Shield Machines

This week in T&TBMs MAS Course was dedicated to the analysis of some particular geological situations that require attention when driving a TBM tunnel as well as to the study of EPB and Hidroshield Closed Shield mode machines. 

We had the privilege of receiving a lecture from Prof. Dr. Paul Marinos (NTUA, Greece) entitled Geological Constraints and Geotechnical Issues in Mechanised Tunnelling. He went through several situations that may be encountered when driving a mechanised tunnel from his wide experience as karstic voids, unpredicted hard/weak rock zones, squeezing ground or high pressure water presence. He provided also the main factors that need to be taken into consideration for the right choice of the machine, presenting many case histories to emphasise that each machine must be carefully selected.

Paul Marinos and the Master's students after his lecture.

After getting a clear idea about the choice of the machine, Alessandro Cresto (Herrenknecht) held an outstanding lecture to explain us thoroughly the EPB and HS Closed Shield TBM main features and technological aspects. In a three day intensive course he focused mainly in topics as:

• field of applicability and potentialities of each type of machine 
• main components design and materials
• components wear and maintenance operations
• special reparations
• support pressure
• backfilling grouting
• guidance systems

A strong background was provided by him presenting some very interesting and impressing case studies from his personal experience in one of the leading TBM construction companies, giving us also a general overview of the trends of the market.

Alessandro Cresto and the students after his lecture on EPB and HS.

Week 13: Closed Shields and Face Stability Design

To begin with this week, Prof. Dr. -Ing. Markus Thewes (Ruhr-Universität Bochum) held a fantastic lecture on Slurry Shield TBM technology. From his consistent research background and his wide experience on the application of this type of machines he covered deeply the most important issues to be taken into consideration. The slurry circuit, separation plants, bentonite suspensions, face support and difficult project conditions were the key points.

Markus Thewes and the Master's students after his lecture on Slurry shields.

Moreno Pescara from Geodata Engineering SpA, gave us a three day intensive course on Segmental Lining design. He went thoroughly through every detail regarding the design, verification, production, transport and assembly of the segments forming a precast concrete ring used in shielded TBMs. He emphasised in the importance of a proper Backfilling Grouting to control the induced settlements and to ensure the correct functioning of this lining system.

Extract of the lecture of Moreno Pescara on Segmental Lining Design.

Finally this week we had the honour to presence a great lecture from Georgios Anagnostou (ETH Zurich, Swiss Federal Institute of Technology) regarding Face Stability Analysis and Design. He went dynamically through the calculation method based on the silo theory and developed by him and his research group to asses the required pressure at the face. Special attention was paid to its application to closed shield machines, certainly this was one of a kind learning experience.

Georgios Anagnostou and the students after his lecture on Face Stability.

Week 12: Getting into Mechanised Tunnelling

Starting with the second modulus of the Master Course, Professor Peila held an introductory lecture on the overall aspects of mechanised tunnelling. He provided us with a clear picture of the developed technology and its main features in order to be prepared for the following lectures from specialists on the topic.

We had the honour of receiving a lecture by Prof. Dr. Kalman Kovári in which he adopted a practical approach to introduce us the aspects to take into account for different tunnel design cases. This interactive lecture was absolutely fruitful to apply and expose the concepts and ideas that we learnt in the past. From his wide experience he proposed some case studies to enhance our critical thinking of the possible solutions to overcome complicated conditions.

Prof. Kalman Kovári and the group of students after his lecture.

Prof. Dr. Nuh Bilgin (Istanbul Technical University) held an outstanding two day course on Cutting Tools and Excavability prediction for Mechanised Tunnelling. He went through the different tool types and its field of applicability, considering also their particular wear phenomena. Main attention was laid to the performance prediction in terms of Net Cutting Rate considering several numerical examples from true cases.

Prof. Dr. Bilgin and Master's students after his lecture on Cutting Tools.

To conclude with this first week of the second modulus, Eric Leca (Arcadis and ITA Executive Council Member) gave us a very interesting lecture on Tunnelling Induced Settlements. Starting from the governing theories with concepts such as the Volume Loss and its sources, he presented the factors to be taken into consideration for a proper tunnel driving in urban areas where the constraints are maximum. A valuable discussion of the monitoring results obtained in some case studies was the way to apply the concepts learnt, resulting in an exciting discussion.

Prof. Eric Leca and the students after his lecture on Tunnelling Induced Settlements.