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.

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.

Week 9 & 10: End of the First Modulus

We reached the end of the first modulus of T&TBMs MAS course with combination of some theoretical principles as lining structural design or risk management with several very interesting case studies.

To start with, Mirko Corigliano from ENEL Italy, covered the main aspects of Seismic design for underground structures. In most of the cases underground structures behaves properly against seismic actions due to its link to the ground and the damping effect of seismic waves with depth. It is important to consider anyway, when applicable, the seismic actions for the structural design of the lining elements in order to avoid undesired consequences such as loss of human lives or functionality.

Engineers Adriano Fava and Francesco Comba from Alpina S.p.A introduced a fantastic case study of a traffic tunnel undergoing the King's castle in Rabat, Morocco. An extremely delicate situation to minimise settlements in order to avoid any damage to this historical buildings lying on weak rocks. It is a great example of precise design and application of ground improvement and monitoring techniques.

Adriano Fava, Francesco Comba and the students after their case history lecture.

Eng. Andrea Pettinaroli held a case history lecture on Artificial Ground Freezing in Warsaw Metro. When underpassing an existing traffic tunnel a face collapse occurred even with a jet grouted arch of pipes due to the presence of a monogranular sand layer under the watertable in proximity of Vistula River. The solution applied to overcome this critical section was the use of Freezing technique, combining open and closed circuit technology they maintained the ground at around -30 °C, reaching this way the completion of a very critical section of the project.

Eng. Andrea Pettinaroli and the students of the Master after his case study lecture.

Harald Wagner (ITA AITES – EXCO Member, Consulting Engineer, Bangkok & Vienna) gave us a very interesting lecture regarding on the impact of Urbanising and the wide range of tunnelling applicability to cope with the raising demand in terms of infrastructure. He presented several case studies from his vast professional experience. 

Fabrizio Barpi from Politecnico di Torino held a fantastic two day course on structural design of composite linings, particularly focusing on the combination of shotcrete with steel ribs. He introduced the main background concepts of the structural theories to then explain thoroughly the procedure proposed by Carranza-Torres (2000). The idea is to use the equivalent section approach to distribute the forces and bending moments on each component of the section to then calculate their capacity diagrams in order to verify the safety conditions.

Fabrizio Barpi and the Master's students after his lecture on lining design.

We had the pleasure of receiving a lecture from Søren Degn Eskesen (ITA President and COWI Tunnel Chief Specialist) oriented to risk management methods. He emphasised on the importance of a thorough definition of every possible hazard to be encountered in a tunnelling project in order to have predefined countermeasures to tackle them as soon as possible and reduce their associated risk.

Søren Degn Eskesen and the students after his lecture on Risk Management Methods.

To finish with the first modulus we had a theoretical exam for the concepts presented until now. To pass the exam of each modulus is a must to obtain the final certificate of the Tunnelling and TBMs MAS Course.

Week 8: Numerical Modelling approach

To start with this week we had a day combining two very interesting topics explained by experts coming from the leading companies in the sector. Firstly, Maurizio Leotta from UTT Mapei (Waterproofing Director) went deeply trough the technologies and solutions applied by his company to waterproof the lining structures. The discussed solutions are not only applicable for tunnels but also for stations and other underground facilities lying under water table or that may expect some water influence in the span of their lifetime. Some application cases were studied focusing on the details and joints between elements, because these are the main source of failure of the system that would lead to undesired situations.

Maurizio Leotta (UTT Mapei) and Students after the lecture on Waterproofing systems.

After this lecture we moved to another topic very important and it is the probing ahead of a TBM face. Thomas Dickmann from Amberg consulting company held an outstanding lecture on geological and geophysical survey applications for TBM technology. He presented some techniques used for the evaluation of the ground properties ahead of the excavation face within the advancement steps. Finally he introduced the procedure developed by his company, the so called TSP (Tunnel Seismic Prediction) to define through a low charge D&B scheme with a good detail the conditions to be encountered.

Tunnel Seismic Prediction by Amberg Company presented by Thomas Dickmann.

In the following days Vincenza Floria (Geodata Engineering) introduced the main aspects and potentialities of Numerical Modelling for underground structures design. She established the theoretical basis considering also a big amount of case studies from her wide experience in Geodata projects all around the world. Thanks to a license provided by ITASCA we were able to apply all the concepts learned by using FLAC software to solve some simple examples performing a parametric analysis on the influence of the modification of certain ground and lining parameters on the system behaviour.

This is an amazingly powerful tool for the design that must be used with skill and knowledge about its limits and background theories.

Floria Vincenza (GEODATA) after her practical lecture on Numerical Modelling by FLAC.

Week 7: Conventional tunnelling and some key concepts

Professor Robert Galler (Montanuniversität Leoben) held an amazing lecture presenting the fundamentals of Austrian approach to Tunnelling. He went from the Conventional excavation technique, taking into consideration the fundamental static behaviour of the ground, to the tendering, design and construction phases, where precise attention is laid to the responsibilities and cooperation between the involved parties. I must say their approach is very smart, not only from the excavation technique viewpoint, so there is quite much to learn from such a solid model.

Professor Robert Galler and students after his lecture on Conventional Tunnelling.

Professor Claudio Oggeri from Politecnico di Torino introduced the General Concepts of Monitoring. This is the key tool for the comparison between the predicted and the real situation of the whole tunnel project, it is also fundamental for the control of the safety and stability from the construction to the operation. Defining threshold values for each measured parameter is a must.

European Standards introduced by Prof. Oggeri regarding Monitoring Plan.

A complete day was dedicated to Concrete Technology by Mapei UTT (Underground Technology Team) experts. Cristiano Maltese tackled the durability of the material from the basic chemistry of the involved reactions, defining the main degradation phenomena and the mitigation measures that must be taken into consideration while designing, preparing, casting and curing the concrete.

Dr. Cristiano Maltese and Master's students after Concrete Technology lecture.

Carlo Pistolesi emphasised on the mix design of concrete, taking into consideration the exposure classes, the required resistance and some other particular requirements of each project to define the right proportions and composition. The conclusion is that knowing very well this material is of paramount importance in order to be able to produce the durable structures required for tunnelling purposes.

Eng. Carlo Pistolesi and the students after his lecture on Concrete Technology.

Professor Peila continued with his series of lectures focused on Ground Improvement techniques, going deeply in this occasion into permeation grouting solution. He presented the technological aspects, grouting mixtures and the design and testing procedures for a proper result in terms of continuity, permeability and strength without causing disturbances to surface structures. The lecture was combined with plenty of case history from his former professional experience as a young engineer in a grouting company.

This week concluded preparing the field for the topic of next week that will be Numerical Modelling. Professor Borri Brunetto from Politecnico di Torino held a fantastic theoretical lecture on the fundamentals of numerical methods, starting from the mathematics of continuum mechanics and going through the background theories solved by Numerical Models to obtain a computationally efficient and convergent to a good approximation solution. 

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.