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