The Group met on Sunday April 23 and Monday April 24. These meetings were attended by 16 participants representing 12 member countries: Austria, China, Korea, Denmark, Spain, United States, France, Italy, Netherlands, United Kingdom, Singapore and the Czech Republic.

The meetings included a progress review of the program agreed at the 2005 Istanbul meeting, as well as a discussion on future actions to be undertaken.

Since the Istanbul meeting, the recommendation on "Settlement Induced by Tunneling in Soft Ground" has been finalized, following the review performed by the referees designated by the Executive Committee and is now ready for publication.

Most of the activity over the past year has been dedicated to the preparation of two recommendations, on "Strategy for site investigations of tunneling projects", on the one hand, and on "Monitoring & Control of Underground Works", on the other hand, as well as participating in the works of the ITA task force on "Risk Management".

The two draft recommendations were reviewed during the first meeting, and a new set of actions agreed for finalizing the documents prior to the Prague meeting.  The two recommendations are meant to provide high level strategic information, and to reflect on the practices of member countries.

The discussion on future works identified "Risk Management" as one key area of activity for the coming years.  Three potential areas of activities were defined:
- actions aimed at facilitating the dissemination of risk management practices; this may include developing educational material for training;
- actions aimed at building a data base providing evidence of the benefits of risk management, based on a review of case histories of projects where the method was successfully implemented;
- follow up document to the 2004 "Guidelines for Tunneling Risk Assessment" issued by WG2.

The Group met on Sunday May 8 and Monday May 9. These meetings were attended by 13 participants representing 12 member countries.

The first meeting was largely dedicated to the review of the draft recommendation on the “Strategy for site investigations of tunneling projects”.  The document is meant to focus on key principles with additional background material being provided in appendices.  The production of the appendices will require the collection of information on guidelines used in member countries, as well as on practices in terms of level of investigation works undertaken for tunneling projects.

The group also reviewed the outline of the document to be prepared in relation to “Monitoring and Control of Underground Works”, and a plan of action was agreed for the production of a draft recommendation. This document should take account of guidelines produced in other countries, notably in Austria, Korea, UK and the recommendation on “Monitoring methods for underground structures” recently published by the French Tunneling Association.

It is expected that the final drafts of the two documents will be produced during the coming year, for review at the Seoul meeting.  Another document prepared by the group on “Settlements induced by tunneling works” is currently under final review and should be ready for publication in the second half of 2005.

During the second meeting, the group also reviewed the “Code of Practice for Risk Management of Tunneling Works” submitted by the insurance and re-insurance companies to the ITA.  The position expressed by WG2 on this document is that a number of issues would tend to make it difficult for this code of practice to be endorsed as currently drafted.

These include:

-          The document is perceived as highly demanding on all stakeholders, particularly if it is to be enforced as a code;

-          It is primarily based on the practice of one country (UK).

-          The document introduces notions such as the concept of “robust design” which definition can be highly subjective;

-          The approach does not leave sufficient room to risk sharing considerations.

It has also been suggested that some clarification should be provided on the levels of losses currently carried by insurance companies in tunnel construction projects. 

On the other hand, it should be recognized that the document focuses on the implementation of a risk assessment and management approach which principles are in accordance with the “Guidelines for tunneling risk management” prepared by WG2.  It is therefore believed that there should be ground, on the basis of this initiative, for establishing a dialogue with insurance companies on the ways to jointly work at managing the risks associated with tunneling projects and improving the quality of project delivery.

The group also discussed communication and working practices and it was agreed that, as far as practicable, more use would be made of the ITA forum to exchange information within the group and progress the activities currently undertaken.

WG2 – Research – Animateur: Eric Leca (France), Vice-Animateur:

Yoshihiro Takano (Japan), Tuteur: Harald Wagner (Austria)

The Group met on Sunday May 23 to review the activity of the past year and elaborate the program of the coming year. This meeting was attended by 14 participants representing 11 member countries.

This year, Yann Leblais presented his resignation as Animateur to the Executive Committee, after leading the Group successfully for eleven years. The Group decided to renew his position by secret vote, according to the Articles of the Association. It also asked unanimously to the Vice-Animateur to remain in place.

The leading team is now composed of:

-          Eric Leca of France, as Animateur;

-          Yoshihiro Takano of Japan, as Vice-Animateur;

and is willing to offer, together with the other group members, a highly motivated team of professionals to the Association.

The activity of the past year has been focused in three areas:

-          Risk Management of Tunneling Projects;

-          Settlements induced by Tunneling;

-          Site investigations.

The document on “Risk Management of Tunneling Projects” has been approved and published. The recommendation on “Settlements induced by tunneling” is now complete and being submitted to the Executive Committee for review. Work has progressed on “Site investigations”, with a draft recommendation being discussed at the meeting on Sunday.

In terms of future work, the group has taken the view that it should primarily concentrate on the compilation and dissemination of knowledge available from existing works. This approach is perceived as an appropriate way to serve the international community, while setting tasks for the group that would be seen as achievable in a reasonable timeframe. A number of practical measures have also been suggested to facilitate group work, including introducing a leader and co-leader for each task and making use of modern communication technologies to exchange between annual meetings. Contributions from member countries that are not represented within the Group will also be welcome.

The following topics will be progressed during the coming year:

-          Site Investigations;

-          Monitoring and Control of Underground Works.

A third action on Security has been discussed but it was decided that further concerting with the other working groups would be required before an action should be launched on this matter.

GT2 – Research – Animateur: Eric Leca (France), Vice-Animateur: Yoshihiro Takano (Japan), Tuteur: Harald Wagner (Austria)

Le Groupe s’est réuni le dimanche 23 mai pour faire un bilan de l’année écoulée et definer le programme de l’année à venir. 14 personnes, représentant 11 nations membres ont participé à cette réunion.

Cette année, Yann Leblais a présenté sa démission de son rôle d’Animateur au Bureau Exécutif, après avoir mené avec succès les travaux du groupe pendant 11 ans. Le Groupe a décidé de procéder à son renouvellement par vote à bulletin secret, conformément aux Statuts de l’Association. Il a également sollicité unanimement le Vice-Animateur pour qu’il conserve ses fonctions.

L’équipe de coordination est maintenant composée de :

-          Eric Leca (France), Animateur ;

-          Yoshihiro Takano (Japon), Vice-Animateur ;

et constitue, avec les autres membres du groupe, une équipe motivée d’acteurs de la profession désireuse d’apporter son concours à l’Association.

L’activité de l’année écoulée s’est articulée autour de trois thèmes :

-          Maîtrise des risques en travaux souterrains ;

-          Tassements liés au creusement des ouvrages souterrains ;

-          Reconnaissances de terrain.

Le document relatif la « Maîtrise des risques en Travaux Souterrains » a été approuvé et publié. La recommandation relative aux « Tassements liés au creusement des ouvrages souterrains » est achevée et soumise au Bureau Exécutif. Les travaux sur les « Reconnaissances de terrain » se sont poursuivis et un premier document a été examiné au cours de la réunion de dimanche.

En ce qui concerne les travaux futurs, le groupe a pris le parti de faire porter son effort sur la compilation et la diffusion de connaissances issues de travaux existants, considérant que cette approche permettait d’apporter une contribution utile à la communauté internationale, tout en se donnant des objectifs réalisables dans des délais raisonnables. Quelques mesures pratiques ont également été évoquées pour faciliter les travaux du groupe, notamment l’introduction d’un double pilotage des actions du groupe et l’utilisation de moyens modernes de communication pour faciliter les échanges entre chaque réunion.

Le programme de l’année à venir porte sur les sujets suivants :

-          Les reconnaissances de terrain ;

-          L’auscultation et le contrôle en travaux souterrains.

Une troisième action sur la Sûreté a également été envisagée, mais il a été jugé qu’une concertation préalable avec les autres groupes de travail était nécessaire avant de pouvoir engager une action dans ce domaine.

Twelve people from ten countries attended the meetings of the Working Group (Austria; Korea; Spain; United States of America; France; Italy; Japan; Netherlands; Romania; United Kingdom).

In Oslo, in 1999, the idea of a reflection on Risk assessment related to the construction of underground works was launched. This work, coordinated by Soren Eskesen (Denmark), is seeing its outcome.

The final version of the text was sent to the Executive Council for its meeting in October 2002 in Moscow. The last version of the report on "Tunnelling Risk Assessment" will be completed, at the request of the Tutor, by a short paragraph on the link between these analyses of risks and costs, and of delays. This addition will be made after and the Group would like the Executive Council to launch now very rapidly the publication of the document in TUST. Perseverance always pays! The resumption of works, almost historic for the Group, on the document devoted to "Settlements related to the Boring of Underground Works", has been actual since Sydney, under the impulse of Eric Leca (France) and of Barry New (UK). The document examined in session only requires linguistic adaptations. The text will be sent for approval to the Executive Council before the summer 2003.

The Group devoted almost all their works to focusing again on the last topic launched in Sydney on site investigations for tunnelling projects, the coordination of which is ensured by Yoshihiro Takano (Japan). The reflection took into account two important lines:

- first line: the Group would like to decline the global aim proposed in Milan by its Animateur, namely that the members of the Group, who have poor means, it should be reminded, are rather there to:

 

- identify, on a given subject, the right practices and the state-of-the-art reports of quality published in the world,

 

- put, if possible, these texts in relative perspectives,

 

- therefore show the way to the tunnelling community, and particularly the most deprived countries, with a methodology of approach;

 

- second line: all work must have clear aims and a delimited field; this evidence is sometimes neglected in the enthusiasm of meetings!

 

On these bases, the Group:

- gave a new name to their work: Strategy for Site Investigations for Tunnelling Projects;

 

- limited their object to the period between the launching of the project at the customer and the beginning of the construction;

 

- extended their scope to the information needed by the customer, by engineering and by the company;

 

- worked out the detailed plan of the text so that the coming year is devoted to the collection of knowledge and practices on precise items.

Finally, the Animateur reminded to the Group that he had started his task in 1993 in Amsterdam, at the very same place, and that he was thinking of being taken over. The reflection on this subject is now open among the members of the Group and will be discussed again in Singapore.

Ten members from six countries (Australia, Denmark, France, Japan, The Netherlands, United Kingdom) attended the meeting of Working Group Research. We have one complete study, two studies in progress and one new study, as follows.

1. State-of-the-arts report on seismic design of tunnel (Coordinator; Youssef Hashash) We had finalized this study in the last meeting in Milan. After the approval of the Executive Council, "Seismic Design and Analysis of Underground Structures - A State-of-the-Arts Report" was published in Volume 16, No.4 of TUST.

2. Settlement induced by urban tunnelling (Coordinator; Eric LECA and Barry NEW) We have studied this theme for more than ten years and we should finalize it in the last year. The target of this study is to make the recommendation. The proposed recommendation is based on the recommendation of AFTES in 1996. In consideration of the development of the tunnelling technology and the technology of analysis of ground movement in these 10 years, we have restarted this study. We will modify the proposed recommendation based on the one made by AFTES with the new standard of each country such as BTS Standard and make the final draft of it in this year. This study will be finalized in the next meeting in Amsterdam and published in TUST in the next year.

3. Risk analysis (Coordinator; Soren ESKESEN) Coordinator presented the final draft of the "Guidelines for Tunnelling Risk Assessment". We agreed it on the main point. Other comments will be accepted by the end of April. Then, with the approval of the Executive Council, the Guidelines will be published in TUST in this year.

4. Site investigation (Coordinator; Yoshihiro TAKANO) This is a new study, which was proposed by Prof. Andre ASSIS firstly, and TAKANO leads this study with the assistance of JTA. The target of this study is to make the Guidelines for Site Investigation of Tunnelling Project. At the first stage, we will collect each guideline or recommendation of each country and make the draft. We will discuss this draft in the next meeting in Amsterdam. It will take about 2 years to finalize this study. We decided to use the website of Working Group to make our activities more efficient.

Sixteen representatives from fourteen countries attended the Working Group's meeting.

I would like to start off with a reminder that the year 2000 was marked by the loss of two loyal members of the group, Virgil Fierbinteanu from Romania and Birger Schmidt form the United States, who passed away due to illness. I would like to pay a deep tribute to them on behalf of the group and the ITA community.

In Durban, the group presented its report to the Executive Committee on the design of lining in tunnels excavated by TBM. This text has been published in the form of a guide in volume 15 of TUST, n°3.

In Milan, the group agreed on the final version of its report on designing earthquake-resistant underground structures. This report has been submitted to the Executive Committee and any corrections will be made next September. So, it could be published for the end of 2001. The group wishes to use TUST as the publishing medium.

Now that these two important stages have been reached, the group will be able to concentrate on completing its report on settlement caused by tunnel excavation and continue working on its global analysis of risks linked to underground construction. On the other hand, the subject which was scheduled in Sao Paolo on the choice of safety margins has been put on hold for now due to a lack of serious commitment from its co-ordinator.

On a more general note, the group proposes improving its capacity to inform the international community by, in the future, writing up more compilations based on national contribution, put into perspective by a preface of four to five pages written by the group.

Lastly, the group plans to use a university course to compile data on settlement witnessed on site, with the aim of validating improvements made on recent sites as regards settlement reduction. This work, in the first place, will involve perfecting the structure of a database. Secondly, the base would be fed with data already available from member groups and thirdly, it would be approved by the ITA as a recommended model and released in country members. If this project is to reach term, it will depend on ITA financial support. This point will be discussed in greater depth after the summer.

Eight members from six countries (Brazil, Denmark, Japan, Singapore, Sweden, and United States) attended the meeting of Working Group Research.

The WG has five studies, as follows.

1.Guidelines for Design of Shield Tunnel Lining (Coordinator; Yoshihiro TAKANO). The WG has finalized these guidelines and submitted them to the Executive Council for approval. After approval, the guidelines will be published in "Tunnelling and Underground Space Technology".

2.State-of-the-art report on seismic design of tunnel (Coordinator; Schmidt BIRGER). The coordinator presented his draft report. It will be reviewed by specialists, (e.g. professors of universities) to check the detailed parts. It will be discussed in Milan and finalized. The report of the final version will be published in 2001.

3.Risk analysis (Coordinator; Soren ESKESEN). The coordinator presented his paper and the draft of guidelines, and proposed the strategy to make the guidelines. The WG organized a Sub-Working Group comprising five members to make the activities more efficient. They will collect reports on the risk analysis and send them to the coordinator. He will make the draft of guidelines of about 20 pages and send it to each member before the end of April 2001.

4.Recommendation on the settlement induced by urban tunnelling (Coordinator; Yann LEBLAIS). This study is now at the final stage, but, could not be discussed because the Coordinator was absent from the meeting.

5.Study on the safety factors of limit state design method of tunnel (Coordinator; Dan EISENSTEIN). The WG could not discuss this study because the coordinator was absent from the meeting.