Around the world

Materials World magazine
13 Oct 2014

Rhiannon Garth Jones takes a look at some of the most exciting and innovative infrastructure megaprojects currently being undertaken.

Human history has been no stranger to infrastructure projects on a grand scale. As well as the architectural wonder that is the pyramids, the Ancient Egyptians built the Lighthouse of Alexandria to guide ships into the great harbour. The Romans were famous for their straight, durable roads, as many a schoolchild will inform you. The Great Wall of China, while not actually visible from the moon, remains a jaw-dropping achievement. The Suez Canal was no schoolboy endeavour, nor were the railways that were built across the vast expanses of North America and the rest of the world in the 19th Century.

In recent years, we have not been shy about emulating the achievements of our ancestors, and some of the infrastructure projects being undertaken around the world today are feats of engineering equal to those that have gone before, requiring imagination and innovation. In the UK, we have seen the Channel Tunnel and now Crossrail, but we are not alone in investing in huge infrastructure programmes.

One such project, the Alaskan Way viaduct, in Seattle, USA, which replaced the section of tunnel damaged by an earthquake in 2001, had a tunnel boring machine (TBM) named Bertha, specially created to work on the four-lane underground tunnel. Bertha is 17.5m in diameter, weighs in at a cool 6,100 tonnes and cost US$80m. This 3.2km tunnel is estimated to cost US$4.25bln and will be completed by 2016. The Alaskan Way viaduct is just one of many megaprojects currently being undertaken in technically challenging areas of the globe. Earthquake zones, high seas and mountain ranges are among the difficulties that today’s engineers encounter, and seem to be overcoming. We take a look at how they’re doing just that.  

Sunda Strait Bridge, Indonesia
Estimated cost: US$10bln
Overall length: 30km
Estimated completion date: 2020, although delays have made this unlikely
This project is actually a series of bridges, carrying a six-lane highway and double-track railway across the three islands of Prajurit, Sangiang and Ular in the Sunda Strait. It will be the most expensive single infrastructure project carried out in Indonesia and will include several of the longest suspension bridges in the world. The strait lies on one of the world’s most dangerous earthquake zones, and the active volcano Krakatoa is only 40km away, adding to the technical challenges faced by engineers working on the project.  

The Gotthard Base Tunnel, Switzerland
Estimated cost: US$10.3bln
Overall length: 152km
Estimated completion date: 2016
After 20 years of construction and preparation, this railway tunnel through the heart of the Swiss Alps will have been one of the most protracted tunnel construction projects in the world in terms of time taken to complete, and will also be the greatest in length. The intention of the tunnel, which is suitable for high-speed trains and heavy freight, is to shift freight volumes from road to rail, reducing the environmental damage caused by heavy lorries.

To cut construction time in half, four access tunnels were built so that construction could start simultaneously at four different sites, and a fifth was later added. The tunnel cuts through the Gotthard Massif Mountain Range 600m below the existing tunnel, to enable faster passage.  

Eurasia Tunnel Project, Turkey
Estimated cost: US$1.4bln
Overall length: 5.4km
Estimated completion date: 2017
The Eurasia Tunnel, built under the Bosphorus straits, is designed to improve traffic management in Istanbul, a city of 14 million people. It will connect the European and Anatolian sides of Istanbul and, more widely, Turkey’s European and Asian road networks.

The project includes a 1.4km earthquake-proof immersed tube, assembled from 11 sections and placed 60 metres below sea level – 55 metres of water and 4.6 metres of earth. The elements weigh up to 18,000 tonnes and are designed to withstand earthquakes of up to 7.5 on the Richter scale, due to concerns about the proximity of the tunnel (18km) to the active North Anatolian Fault.  

The Qinghai–Tibet railway, China
Estimated cost: US$3.5bln
Overall length: 1,956km
80% – of track higher than 4,000m
The Qinghai–Tibet railway, coined the closest stretch of railway to the sky, carries passengers at heights reaching more than 5,000m. With 80% of the track higher than 4,000m, passengers have to seek medical approval to travel. The stretch between Golmud and Lhasa, completed in 2005, was laid in temperatures ranging from a wintry -35°C to more than 30°C in the summer.

Providing a steady, reliable signalling and communication system over such a long distance and in such a harsh environment presented its own problems, not least in terms of continuity of electrical supply. An assistant solar power system was used, consisting of nine supply stations with a gross capacity of 122.4kW, and a further seven supply stations along the length of the railway.  

Dubai Waterfront, UAE
Estimated cost: US$16bln
Estimated length: 440km2
The UAE is famous for its astonishing man-made infrastructures, and this waterfront looks set to further that reputation. The conglomeration of canals and artificial archipelago will occupy the last remaining Persian Gulf coastline of Dubai, and is expected to become the largest waterfront and man-made development in the world.  

East Side Access, USA

Estimated cost: US$10.8bln
Estimated completion date: 2023
A controlled drill-and-blast method, using two 640-tonne TBMs, is being used to build a new East Side rail station below the Grand Central Terminal in New York City. The TBMs bore 15m a day, working beneath the busiest railroad interlocking in the country, which handles 800 trains every day.   

Ohio River Bridges Project, USA
Estimated cost: US$16bln
Estimated length: 440km2
This project will overhaul a metropolitan transport area – rebuilding the Kennedy Interchange, completing two new bridges over the Ohio River and reconstructing various ramps. It will be the largest transportation project constructed between the two states, and it is hoped it will reduce the region’s traffic congestion.   

Panama Canal expansion, Panama
Estimated cost: US$5.25bln
Estimated completion date: 2015
The work will double the capacity of the Panama Canal by creating a new lane of traffic and allowing more, and larger, ships to transit. Concerns have been raised over the possible impact of the work on biodiversity. However, the National Association for Nature Conservation in Panama believes there will be very low levels of salinisation, which will maintain biodiversity and water quality for human use.