Week 6: Tunnelling applied technology

We have reached the sixth week in Tunnel and Tunnelling Boring Machines Master Course.

This week was dedicated to some tools for tunnelling excavation as Formworks, Rock Drilling tools and Mechanical Cutting equipments.

Specialised crew from CIFA (Underground Concrete Machineries) gave a complete overview of their available technology for Formworks. Eugenio Bertino introduced precast segments moulds and the different plant layouts for the production system depending on the project requirements. Later on, Giovanni Esposito completed the topic speaking about Cast in-situ formworks, explaining the principles of self supporting and self reacting technologies, emphasising on the details for a proper application at the job site.

Bertino and Esposito from CIFA and Students after Formworks lecture.

Another company that presented his technology this week was SANDVIK (Mining and Construction Tools), particularly they exposed Rock Drilling Tools and Roadheader equipments.

Juha Kukkonen dedicated a complete day to Rock Drilling machines and tools produced for tunnelling and mining applications. Jumbos for D&B excavation, Bolting units and Extension Drilling equipments were treated in detail, analysing the control systems of the machine that ensure the best possible results in terms of production and final product.

Juha Kukkonen from SANDVIK and Students after Rock Drilling Machines lecture.

Thomas Peinsitt presented the whole catalog of available products for Mechanical Cutting equipment, focusing mainly on Roadheaders. He went through its mechanical features, cutting sequence, cuttability parameters, wear phenomena and finally safety and ventilation aspects. Thomas shown the potential of this rarely applied technique through many case studies.

Thomas Peinsitt (SANDVIK) lecture on Mechanical Cutting and Roadheaders.

To conclude this week Director of the course Prof. Daniele Peila held a very interesting lecture on soft ground improvement techniques as forepoling, face reinforcement, drainage and jet grouting, describing deeply their particular features and design procedures. Great part of the lecture was reserved to case studies from his professional experience in order to understand the wide range of possibilities available to enhance the properties of the material to be excavated and guarantee safe and stable working conditions.

Professor Peila lecture on Ground Improvement.

Week 5: Excavating and supporting rock masses

Last week in Tunnelling and Tunnel Boring Machines MAS course was focused on two wide conventional tunnelling fields as Drill and Blast excavation technique and first phase support for rock masses.

Dr. Daniele Martinelli (Rockplan - Politecnico di Torino) introduced the D&B technique, from explosives and detonators to the design of the whole blasting scheme. Another key concept is the management of blasting induced vibrations to avoid disturbances to surface structures. From his wide experience in Baltic hard rocks excavation at Rockplan (Finnish rock structures design company) he presented some practical examples and exercises to reassure the concepts.

Dr. Martinelli and Students after his lecture on hard rock excavation examples from Rockplan. 

Stefano Airoldi from Orica explained the technology and field of applicability of the bolts produced by his company, merging the theoretical concepts of each type of bolt with his background from a large career in rock improvement technique. Dr. Martinelli proposed a calculus example for bolting technique and same case studies. 

Orica bolting technology presented by Stefano Airoldi.

Dal Negro Enrico from Mapei (Construction Equipment Supplier) held a fantastic lecture focused on sprayed concrete for first phase lining applications both for temporary and permanent solutions. He presented dry and wet mixtures technologies focusing mainly in the latter as it is the one applied in almost 95% of the cases.

Sprayed concrete technology presented by Mapei UTT leader Dal Negro Enrico.

 Two experts from Bekaert Maccaferri (De Rivaz, Benoit and Rossi, Bruno) gave an outstanding presentation on the use of fibre reinforced concrete technology for tunnelling applications. Cast in-situ final lining, Precast concrete segments and last but not least Sprayed concrete are the main field of applicability for this innovative solution that provide fantastic performance, faster and safer working conditions than conventional steel reinforced concrete. 

De Rivaz, Rossi and students after the lecture on fibre reinforcement for tunnelling applications.

Finally Dr. Martinelli presented the concept of grouting for rock masses combined with several practical examples from his own experience at Rockplan company. Some time was given also to a case study of the approach taken by the company to some very interesting projects as metro tunnels and a nuclear repository in Finland.

Rockplan rock structures design case studies presented by Dr. Martinelli.

Week 4: Getting into Tunnelling

In the past week at T&TBM Master there was a combination of very interesting lessons held by high level professors that resulted in a great learning experience.

On Monday, directly from Lyon, Robert Galler (Montanuniversität Leoben) gave a video conference lecture for three simultaneous spectators: T&TBM Master's students at Politecnico di Torino, a University board at Paris and face to face with Master's students at Lyon (Tunnels et Ouvrages souterrains). 

The title of the lecture was Sustainable Tunnelling - Focus on Resource Efficiency and it was part of an experimental video-lecture approach being investigated as the future of training courses, conceived mainly for emerging countries with short access to specialised tunnelling education.

Robert Galler's video conference lecture from Lyon seen from Politecnico di Torino.

The quality of the lecture was perfect, interactive questions from each of the parties were really useful so finally feedback of the students was very positive from this experience.

The following lecture was held by Eng. Piergiorgio Grasso, president and founder of GEODATA Consulting and ITACET foundation Vice President. There are few words to say about such an outstanding professional, and his lecture on Layout Parameters for the Design and Risk Management in Tunnelling was a proof of it. Definitely one of the most remarkable lectures to learn from the experience of today's leaders in tunnelling industry.

Students and Eng. Piergiorgio Grasso after his lecture at T&TBM's Master Course.

Geologist Lo Russo Stefano from Politecnico di Torino provided a lesson on the fundamental aspects of water control in Tunnelling projects. He merged some basic concepts of hydrogeology with his professional experience from several big projects involving water resource management. Special remark was the need of searching smart solutions to overcome underground in-rushes treating the water as a resource instead of as a problem.

Stefano Lo Russo, Hydrogeology in Tunnelling lecture's.

Finally the director of this Master Course Professor Daniele Peila introduced the fundamental concepts of support techniques both for conventional and mechanised tunnelling. Special attention was laid to the design phase of first phase supports through empirical, analytic and numerical methods. The remarked concept by Prof. Peila was that none of the results of these methods should never be taken as a closed solution for any problem, instead we must consider the specificity of each project merged with the constructor experience.

A special opportunity was the visit to the Tunnelling and Underground Space Centre (TUSC) Laboratory at Politecnico di Torino. At this incredibly modern research centre several tests for Tunnelling industry are carried on mainly on Soil Conditioning for EPB, Wear tests, Extraction tests and some other innovative research devices are tested to model the reaction of the ground to the mechanised excavation process. We had the opportunity to presence some tests carried out on bicomponent grouting mixes for backfilling purposes. Special thanks are given to Eng. Carmine Todaro who introduced the main properties of this material and its characterisation process.

Eng. Todaro, Students and Prof. Peila at TUSC Research Laboratory.

Week 3: Rock mechanics week

The third week of T&TBM's Master course have been fully dedicated to study the main concepts of Rock Mechanics. Special emphasis on characterisation and modelling of rock masses, taking into account intact rock and discontinuities properties was laid.

Professor Monica Barbero from Politecnico di Torino covered three days of both practical and theoretical lectures with a fantastic didactic approach. After introducing the most important concepts for the characterisation of rock masses she presented some stereonet examples (hand drawn and with DIPS software) for the analysis of the possible kinematisms within the tunnel profile.

Kynematic analysis of an example presented by Prof. Barbero using DIPS software.

Following with the rock mass characterisation process, Dr. Giordano Russo from Geodata Engineering held a formidable lecture on Geomechanical Classification methods. From the first Terzaghi's approach (1946), following with Deere (1964), Bieniawski (1973), Barton (1995), Palmstrom (1995) and Hoek (1995) as the most widespread criteria in time he reached the actual approach applied and developed by Geodata company (GD Classification, Russo et al. 2007) shown below.

Master's students and Dr. Giordano Russo after his lecture on Geomechanical Classifications.

GD Classification for the characterisation of excavation behaviour (Russo et al. 2007)

Concluding this third week we visited the Politecnico di Torino Geotechnics and Rock Mechanics laboratory DIPLAB (DIsaster Planing LABoratory). Dr. Oronzo Pallara as the Technical Director of the laboratory conduced the visit introducing the available testing devices. From Direct Shear Devices, Oedometers, Uniaxial compressive presses, Triaxial apparatuses, to many other specialised devices for research purposes and for the laboratory characterisation of the soil, intact rock and discontinuities are available in this fantastic and modern laboratory.

Students, Professor Monica Barbero and Dr. Oronzo Pallara after the visit to the Politecnico laboratories.

Professor Monica Barbero and Dr. Oronzo Pallara introducing the laboratory to the students.

Dr. Oronzo Pallara explaining to the students the triaxial tests at soil mechanics laboratory.