Dubai hub for international networking 26 Apr 2018

Since joining the International Tunnelling and Underground Space Association in 2011, much has been achieved by Member Nation United Arab Emirates. As well as holding its own series of annual tunnelling conferences, the Tunnelling Chapter of the UAE Society of Engineers was successful in its bid in 2015 to host the World Tunnel Congress (WTC) in 2018 and the 44th General Assembly of the 74 Member Nations of the International Tunnelling Association (ITA).

More than 1,700 delegates are reported as joining the annual gathering of the international tunnelling industry to appreciate a programme of technical session presentations and an exhibition of nearly 200 leading companies of equipment, materials, products and services to the industry.

The congress theme Underground space for building future sustainable cities was particularly apt for the host region of the world and the UAE host city Dubai, a glittering conurbation of concrete and glass rising from the desert, among them the Burj Khalifa tallest building in the world, the Burj Al Arab iconic sail building and the Palm Jumeirah manmade island. As well as reaching high into the air with its urban planning and development, the city has recognized the vital role of underground space for its sustainable future. As well as designs on building a hyperloop system of supersonic transportation, Dubai has projects underway to build out its metro system with added lengths underground, is expanding its sewerage system and is investing in stormwater and groundwater drainage. The 15km metro Red Line extension, with a 4km underground section with two underground stations, is to be opened in time to support the city’s hosting of the international Expo event in 2020. One of the post congress technical tours was to the operation of a 10m diameter Herrenknecht EPBM that is excavating a single tube, double track running tunnel for the underground alignment.

Significant to the congress theme was the topic of the Sir Alan Muir Wood Lecture, delivered this year by Ed Cording of the USA. In his presentation, titled Monitoring and controlling ground behavior and the source – Recent applications to pressurized tunneling, Cording, as a geotechnical consultant and Professor Emeritus of Civil and Environmental Engineering at the University of Illinois at Urbana-Champaign, tracked the research and development of the ability to control ground movement and surface settlement when using modern TBMs to excavate tunnels beneath sensitive urban areas and city centres. He described the operation of several benchmarking TBM projects that illustrate without any doubt that the these machines can excavate tunnels through soft ground conditions and avoid any surface settlement damage without the use of supplementary processes such as compensation grouting. One of the examples described in detail is the operation of the 17.5m diameter EPB TBM that completed the Alaskan Way SR99 high viaduct replacement tunnel beneath the city of Seattle. Despite the hold up caused by the need to replace the main bearing, the machine demonstrated clearly its ability to be operated to control ground movement and prevent any damaging surface settlement, limiting settlement readings to millimeters and well below predictions.

Next year at the WTC in Naples, Italy, Martin Herrenknecht has accepted the ITA invitation to deliver the 2019 Muir Wood Lecture.

At the ITA Open Session on Tuesday morning, a panel discussion explored the topic of Contractual Practices for the 21^st Century and the development of the ITA/FIDIC Emerald Book of conditions of contract specifically for tunnelling and underground works. The panelists included representatives of project owners for the BBT Brenner Baseline Tunnel between Austria and Italy and the Government of Saudi Arabia as owner, procurer and operator of underground infrastructure; the World Bank as a funding agency of tunnelling projects particularly in underdeveloped and developing countries; SMEC as a consulting engineer and designer of underground infrastructure; the International Tunnelling Insurance Group (ITIG); and Contractor Bouygues of France, which undertakes major tunnel construction projects under various contract and procurement arrangements in different parts of the world.

The panel and the its question and answer session that engaged the audience addresses the fact that construction of tunnels and underground structures is seen as very expensive, always over cost and difficult to manage by owners. The ability of the various forms of contract to control the variables and manage the risks involved is considered an important influence on the outcome of underground excavation projects and taking this further the ITA is working in collaboration with FIDIC, the International Federation of Consulting Engineers, to publish a set of conditions of contract that are specific to the management and control of underground construction projects.

To be published as the Emerald Book, Matthias Neuenschwander, Chair of the FIDIC-ITA Trask Group 10, described the most important features of the new conditions of contract as:

• A balanced sharing of the ground related risk: the owner shall bear the risk of the ground being better or worse than anticipated, and the contractor shall bear the risk of the time and cost for excavation and support in the expected ground conditions.
• Provisions for dealing with unforeseeable ground conditions will be included in the General Conditions of Contract: a good contract should also state how to proceed in order to find solutions when something unexpected occurs.
• It will be a Form under the accepted and widely used FIDIC standard, with the endorsement of the ITA. An existing FIDIC set of General Conditions of Contract for design-build construction works has been taken, and only a minor portion of the clauses required adaptation in order to suit the nature of underground works.
• Apart from the particular clauses created especially for the use in underground works, the Emerald Book includes (as the other FIDIC forms) a provision for a standing Dispute Avoidance and Adjudication Board (DAAB). This is a committee of independent experts who in case of a dispute shall in a short lapse of time issue an adjudication. This adjudication should be binding to the parties unless and until challenged and overturned by an arbitration or an ordinary tribunal. This provision has proven effective worldwide for more than 40 years, shortening time and cutting costs of disputes.
• The Emerald Book will be accompanied by a Guidance for the Preparation of Tender Documents, to assist owners in the tasks they should perform in order to produce a call for tenders that will lead to a robust and balanced contract.

Neuenschwander announced that the new conditions of contract has passed through two of three stages of review successfully and with the last stage scheduled for Autumn 2018, the Emerald Book is expected for publication at the end of 2018 or in the first quarter of 2019.

As a result of the panel discussions, Bill Edgerton of McMillen Jacobs Associates of the USA submitted a Discussion Forum contribution to TunnelTalk to keep the discussion going and widen the field of debate. The panel discussion session was also recorded and TunnelTalk will bring an edited copy of the recording to readers next week.

In other ITA news, the General Assembly welcomed Keith Bannerman of Australia as the new Chair of the ITA Young Members, taking over from current Chair Sindre Log of Norway for a two-year team and Denmark was announced as the uncontested host of the WTC in 2021 after Malaysia in 2020 and Italy in 2019.

The proceeding of the WTC and of the General Assembly in Dubai had an air of optimism and progressiveness about it. Like the city itself there was a sense of can-do and high ambitions for both the industry and for the ITA itself, with technical presentations providing details of overcoming challenges and taking new developments forward and the ITA looking forward to its coming years of growth and international recognition as the industry’s leading voice of influence.

The next WTC will be in Italy in Naples in May 3-6 2019.

TunnelTalk looks forward to meeting friends and colleagues then and at the several local industry conferences and exhibitions in the meantime.