TC Activity
TC 28: Underground Construction in Soft Ground
In recent decades there has been a massive development of large cities throughout the world. Due to the lack of surface space and the need for extensive transport infrastructure systems, there is an increasing rapid growth in underground construction in these urban environments with significant tunnelling and excavation works.
Technical Committee TC 28 has a major commitment towards consolidating and sharing technical knowledge and experience in the investigation, design, analysis and construction of underground works in the urban environment, including tunnels, caverns and deep excavations. The main topics addressed by the committee are:
– Tunnelling in soft ground;
– Deep excavations;
– Monitoring the effects of underground works;
– Numerical analysis of tunnels and deep excavations, assessing both stability and induced movements and deformations;
– Protective measures, ground treatment, control of groundwater inflow and deformations (e.g. by compensation grouting);
– Safety, risk and hazard management.
The primary activity of TC28 is the organising of an international conference every three years. After the first symposium at New Delhi in 1994, symposia have subsequently been regularly organised: London (1996), Tokyo (1999), Toulouse (2002), Amsterdam (2005). These symposia, for all of which comprehensive proceedings have been produced containing the written papers, selected and reviewed by members of TC28, along with general reports and special lectures, thus provide a regular means of presenting information about the latest construction projects and research linked to the theme of Underground Construction in Soft Ground.
The next TC28 symposium is to take place in Shanghai in April 2008 and will be organised by the University of Tongji in Shanghai (HW Huang, & GB Liu) with the support of Hong Kong University of Science and Technology (CWW Ng). To date the organising committee has received more than 260 abstracts. Further information can be obtained on the conference website: http://www.tc28- shanghai.org.
TC28 is supporting a regional one-day workshop on 12th September 2007 to be held in Perth, Western Australia. This is being organised by Eric Hudson- Smith (TC28 core member representing Australia) with the support of the Australian Tunnelling Society (ATS). Further details can be found on the website: http://www.ats.org.au/whatson.php. TC28 also plans to hold a workshop in Budapest in 2008, to be organised by József Mecsi (core member representing Hungary).Two new activities have recently been launched by TC28 following the committee meeting held during the Amsterdam conference in 2005. The first concerns the creation of a database relating to tunnelling and deep excavation works and the second the preparation of guidelines for comparing field or physical model observations with numerical simulations.
Site visits during the TC28 International Symposium in Toulouse (2002)
Database for tunnelling and deep excavations
Databases relating to tunnelling and deep excavation works potentially have great benefit from modelling, validation and case study viewpoints. Experience in this field has shown that there are often many difficulties with such databases when they are created within the framework of committees or associations. A typical example is that the pre-established form to be completed by those compiling the database, is rarely compatible
with the information available from the actual working cases. There are also frequently issues relating to the maintenance of the database after its creation. It was decided at the meeting that a well-organised database could provide significant benefit to the committee, providing information from international sources. Therefore work has been initiated to set up a new database, taking into account recent developments that allow a more flexible organisation and identify key input information required. A group from INSA at Lyon (R. Kastner and F. Emeriault looking after the geotechnical aspects and R. Louis-Sydney the information technology aspects) have started creating this database. A working meeting concerning its organisation was held in Lyon in December 2006 with J. Standing, and an initial version is now available. This version will be provided to interested members of TC28 and presented and discussed at a meeting to be held at the forthcoming ECSMGE in Madrid for critical review and final implementation.
Guidelines for comparing field or physical model observations with numerical simulations
Currently many papers are published comparing numerical or theoretical simulations and predictions with data from field or physical model observations. These are often too basic. The intention with this second proposed theme is to write simple guidelines on this subject, e.g. taking into account basic scientific rules and making sure that sufficient information is provided so that the paper can be considered useful. A sub-committee is soon to be set up to take charge of the organisation of this activity and to progress this activity.
The next meeting of members of TC28 will take place on 27 September 2007 at the next 14th European Conference on Soil Mechanics and Geotechnical Engineering being held in Madrid.
Reported by Richard Kastner, chairman of TC28 and Jamie Standing, secretary of TC28
Download ISSMGE Bulletin – Volume 1 Issue 2 (pp. 3-4)
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