At Mott MacDonald we strive to combine innovative approaches to tunnelling with proven technology to produce winning solutions. And to ensure we’re at the forefront of tunnel engineering, we’re continually researching and developing leading edge engineering solutions for the wide variety of projects we undertake.

Awards and accolades

Testimony to this is our portfolio of industry awards going back all the way to the Channel Tunnel, the recipient of an array of accolades – just two of which include the British Construction Industry (BCI) Special Award for an Outstanding Feat of Civil Engineering and the Concrete Society Award in the civil engineering category.

Proving one of our most innovative projects and prolific award winners, the Boston Central Artery jacked tunnel in the USA has scooped a series of high profile awards. These include the USA’s Civil Engineering Research Foundation’s Premier Award for Innovation – the Charles Pankow Award – created by the American Society of Civil Engineers to recognise collaborative work in introducing innovation to design and construction. The project’s latest award – its tenth no less – is the 2004 Nova Award for innovation.

Also in North America the Canadian Consulting Engineers Awards honoured the St Clair River Tunnel with the Schreyer Award for civil engineering, its highest distinction, and presented an Award of Excellence for the twin tunnels on Toronto’s Sheppard Subway – which brought us further recognition when the Construction Management Association of America presented its 2003 International Project of the Year Award to the joint venture incorporating our team.

Limehouse Link highway tunnel in the UK also won a BCI Award where our input on the cut-and-cover tunnel – especially our application of the observational method – resulted in substantial cost and time savings. Another plaudit came from the Institution of Civil Engineers which granted a special mention for engineering innovation to the Heathrow Express tunnel which we directed for BAA. The Medway Tunnel was the first immersed tube in the UK to be constructed without an external membrane and won awards from both the Concrete Society and the Institution of Civil Engineers.

The most recent award for our tunnelling team has been the 2004 Tunnelling Industry Award for Excellence in Tunnel Design, for our work on the San Diego Mission Valley light rail transit project in California, USA.

Kuala Lumpur’s Stormwater Management and Road Tunnel (SMART) – currently under construction – will be the first dual purpose tunnel of its kind in the world

Ongoing advances

Our innovation in design continues with the unique SMART project in Malaysia. Conceived as a flood relief tunnel to divert floodwaters away from Kuala Lumpur city centre, it was considered that the 11.8m internal diameter tunnel could double up as a two-deck motorway in low rainfall periods to relieve traffic congestion. Mott MacDonald has carried out the feasibility study as well as the detailed design services to take the project from concept through to construction.

Over the years we have been associated with many innovations in the tunnelling field, just a few of which include:

• the bentonite slurry shield for soft ground tunnelling
• large scale use of epoxy-coated reinforcement for tunnel linings
• soil injection and chemical ground treatment to aid tunnelling progress
• special segmental linings to accommodate openings without hindering the TBM advance
  

Research and development

Following a number of recent research projects relating to the use of shotcrete or sprayed concrete lined tunnels and shafts, we pioneered the use of the sequential excavation method (SEM) in the UK. Our continual assessment of SEM application has enabled us to advance the understanding of the system so that we can now offer state-of-the-art analysis and designs for this form of tunnelling.

In the 1970s we conceived, patented and developed the technique of utilising a thixotropic material such as bentonite to support unstable ground encountered at the face of a tunnelling machine passing through water-bearing sands or gravels Our expertise and experience in fire and life safety and tunnel ventilation systems have been recognised in commissions from the UK Department of Transport to provide guidelines and standards for the whole of the UK in this specialist area of tunnel design.

Since its inception we have been almost continually represented on the committee of the British Tunnelling Society, with our senior staff holding the position of chairman over several years. Our tunnelling staff have acted as advisors to the editorial advisory board and have also had representation as animateurs for the International Tunnelling Association. Our engineers have regularly authored papers for international conferences and publications on all aspects of tunnel planning, design, analysis and construction.