Realistic Simulation Supports Expansion of the London Underground

By Akio

Dubbed “one of the most complex tunneling projects in the U.K.,” the Bond Street Station Upgrade (BSSU) project is being carried out to satisfy growing traffic demands within London’s busiest shopping district, the West End.

Upon its completion, Bond Street Station’s daily passenger numbers are expected to rise from 155,000 to 225,000.

A project this complex in nature has to consider the existing tunnel infrastructure, as well as the stress and strains imposed by the surrounding soil layers for the development of new tunnels.

Dr. Sauer and Partners was contracted to provide such tunneling expertise. The company took on responsibility for preliminary-to-detailed design and construction on all BSSU sprayed concrete lined (SCL) tunnels.

Tweet: The Bond Street Station Upgrade utilized realistic #simulation to test preliminary tunnel designs. @Dassault3DS #AEC http://ctt.ec/X4UWh+Click to tweet: “The Bond Street Station Upgrade utilized
realistic #simulation to test preliminary tunnel designs.”

 

Using FEA simulation, they were able to virtually test the ground through which the tunnels are being dug alongside the existing tunnel structures.

Model1.000

This realistic assessment enabled them to improve upon the preliminary design, as well as bring greater confidence to the overall approval process.

To learn more, read the case study, “Tunnel Vision” to see how realistic simulation plays an important role in tunnel excavation.

We also encourage you to download the whitepaper by Ali Nasekhian, Sr. Tunnel/Geotechnical engineer at Dr. Sauer and Partners, which highlights the merits and shortcomings of large 3D models in tunneling.

Tweet: Realistic #Simulation Supports Expansion of the #LondonUnderground @Dassault3DS @3DSAEC #AEC #BIM http://ctt.ec/dU4NO+

Click to tweet this article.

 


Related resources:

White Paper: “Mega 3D-FE Models in Tunneling Bond Street Station Upgrade Project”

Case Study: “Tunnel Vision”

Collaborative and Industrialized Construction Solutions

SIMULIA Solutions page

Game-changing graphene: the amazing properties of a single-atom layer of carbon

By Catherine

Written by Catherine Bolgar

 

Step aside, silicon. There’s a new substance that promises to revolutionize medicine, industry, water treatment, electronics and much more. That substance is graphene—a single-atom-thick layer of carbon, a millionth of the width of a human hair.

 

iStock_000039618600_Small

The world’s first two-dimensional material, graphene is potentially plentiful (carbon being the sixth most abundant element in the universe) and cheap. And it possesses amazing qualities and potential uses:

It’s transparent, but conducts…

electricity and heat. Most good conductors are metals such as copper, which is opaque and quick to heat when electricity passes through. But they are prone to hot spots, which form around defects and cause electronic devices to fail. Graphene, by contrast, transfers heat efficiently. “It’s a good alternative to copper,” says Nai-Chang Yeh, professor of physics at California Institute of Technology. Indeed, electronic equipment may in future use graphene-coated copper interconnections to prevent overheating or wear and tear.

It’s light and flexible, but it is…

Hands of scientific showing a piece of graphene with hexagonal molecule.200 time stronger than steel. The carbon-to-carbon bond is very strong, says Rahul Nair, Royal Society fellow at the University of Manchester. In addition, graphene’s carbon atoms are arranged in a tight, uniform honeycomb structure, which is able to bear loads and resist tearing. A membrane of graphene could withstand strong force without breaking, says Dr. Yeh. It may someday be used in aerospace, transportation, construction and defense.

 

It’s a superlubricant

“If you take one piece of flawless graphene and put it on top of another, and slide one against the other, there’s almost no friction,” says Dr. Yeh. Coating machines parts with graphene could minimize unwanted friction, providing industry with countless applications.

It’s impermeable…

Graphene’s honeycomb structure is too tight for any molecules to squeeze through. “If you have graphene on metal, it’s perfect protection, because other molecules in the air cannot penetrate that honeycomb hole,” says Dr. Yeh. Indeed, Dr. Nair has dissolved graphene oxide in water to create a paint-like film that can protect any surface from corrosion. This graphene paint could be used by the oil and gas industry to protect equipment against saltwater, or by pharmaceutical and food packaging firms to block out oxygen and moisture, thereby extending their products’ shelf life, says Dr. Nair.

…but can also be permeable. A single-micrometer-thick film containing thousands of layers of graphene oxide has nanosize capillaries between its layers, which expand when exposed to water. However, those capillaries don’t expand when exposed to other substances. This is unusual because a water molecule is bigger than a helium or hydrogen molecule. However, water behaves differently when it’s within the confined space of a nanometer, moving rapidly through the graphene oxide nanocapillary. By contrast, salt that is dissolved in the water is blocked. One use for this, says Dr. Nair, could be water or molecular filtration.

It’s a chemical contradiction

A sheet of graphene is inert, but its edges are chemically reactive, says Dr. Yeh. A little graphene flake has a large perimeter relative to its area, allowing for more reaction. These flakes could be used to remove toxins from water.

It can be magnetic

MagnetThe zigzag-shaped edges of graphene have magnetic properties.“People imagine that you will be able to use graphene sheets as a magnet that can pick up iron at room temperature,” explains Dr. Yeh. That something all-carbon can be magnetic is “amazing,” she adds. Coupled with its electric conductivity, graphene’s magnetic properties may open up all sorts of applications in spintronics and semiconductors.

Graphene’s potential may be extraordinary, but how easy is it to create? It was first isolated in 2004 at Manchester University by Andre Geim and Konstantin Novoselov who won the 2010 physics Nobel Prize for their work. They arrived at graphene by using adhesive tape to peel off ever-thinner layers from graphite, a process subject to continual improvement. In one common method, copper is heated to 1,000 degrees Celsius, near its melting point. Methane gas, comprising carbon and hydrogen molecules, is then added, and the copper rips off the bond between the two molecules, dissolving the carbon into the copper and letting the carbon “grow” on the surface, Dr. Yeh explains. The result is a sheet of graphene.

David Boyd and Wei-Hsiang Lin, working with Dr. Yeh at Caltech, however, found that what counts most is not heat but clean copper.  Copper oxidizes quickly in air and so has a thin layer of carbon oxide on its surface. They use hydrogen plasma, which has “gas radicals that behave like erasers and clean up the surface of the copper,” Dr. Yeh explains. The process allows graphene to grow in five minutes at room temperature.

Most importantly, this method could be scaled up to produce industrial amounts of high-quality graphene—a huge step towards realizing its true potential.

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. 

For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

 

Photos courtesy of iStock

Test tube transport: the Hyperloop nears reality

By Catherine

Written by Catherine Bolgar, in association with WSJ custom studios

 

Source: Hyperloop Transportation Technologies

Source: Hyperloop Transportation Technologies

Imagine traveling in capsules sucked through a tube using low air pressure and magnetic acceleration to achieve speeds of up to 760 miles (1,223 km) per hour. That’s the idea of the California Hyperloop, which could eventually cut the travel time between Los Angeles and San Francisco to a mere 30 minutes, compared with today’s one-hour flight or six-hour car journey.

As soon as next year, a full-scale test track will begin construction in Quay Valley, a proposed sustainable community located between California’s two major metropolises.

The Hyperloop is a system that not only makes sense because it’s cheaper to construct, but it’s also sustainable so it’s cheaper to run,” says Dirk Ahlborn, chief executive officer of Hyperloop Transportation Technologies, Inc. “It changes the world.”

Tesla founder Elon Musk first laid out his Hyperloop vision in 2013 and invited others to take up the challenge. Turning the idea into a full-scale model in just three years may seem fast, but, as Mr. Ahlborn points out, it took a decade to get to the moon—“a way more difficult task,” he says. “The Hyperloop technology sounds like science fiction but, in the end, everything we’re doing already exists. The Quay Valley track is necessary to find out how to optimize the technology.”

The Hyperloop concept is similar to the pneumatic tubes used by banks to carry cash and documents, except that the passenger capsules would be sucked through the tube by controlled propulsion. A capsule (with large doors for speedy boarding) would enter a tightly sealed exterior shell. The tubes would probably be constructed from steel—although other materials, including fiberglass, are being considered—and covered with solar panels to supply the system’s energy. Low air pressure—of around 100 Pascals—would reduce air resistance inside the tube, while magnetic levitation and an air cushion would allow the capsule to hover above the tube’s surface. The straight track would further aid speed. As on a flight, passengers would sense how fast they are moving only when the capsule accelerates, slows or turns.

 

Hyperloop. Source: Forbes

Hyperloop. Source: Forbes

The Quay Valley track will allow engineers to work out optimum capsule size and boarding procedures. Each capsule is currently expected to seat 28 passengers and depart every 30 seconds during peak times, allowing a full-size Hyperloop to transport some 3,360 passengers an hour.

The Hyperloop would be elevated on pylons, making it possible to place the route above existing infrastructure such as highways, while also simplifying the process of obtaining right of way and minimizing the environmental impact.

More importantly, the pylons would be flexible enough to withstand earthquakes, in the way that pylons built in the 1970s to carry Alaska’s oil pipeline have proved resilient to such shocks, Mr. Ahlborn notes. As an enclosed system, the Hyperloop would also be impervious to harsh weather.

Perhaps more revolutionary than the technology is the way the Hyperloop team itself works. As well as partnering with companies and universities, more than 300 experts from 21 countries have been brought onto the team, working remotely online. Although they don’t get paid—most hold day jobs as engineers—they do get company stock options. “They’re driven by passion,” says Mr. Ahlborn.

The Hyperloop is groundbreaking in a commercial sense, too. It is expected to cost $16 billion to build, versus $68 billion for a comparable California high-speed rail line. Ticket prices for the Los Angeles-San Francisco stretch, at $20- $30, would be far cheaper than flying, and even that business model is open to disruption. “Do we need tickets?” asks Mr. Ahlborn. “Or are there other ways in which we can generate enough income.” Maybe the Hyperloop could “make more money having more people ride and we can say it’s free. Or maybe it’s free at certain times, and at peak times it costs a bit,” he adds.

The Hyperloop turns conventional infrastructure on its head, from its technology to its crowdsourcing. “Usually these things are done behind closed doors in a boardroom. We’re trying to be open. We’re using the community to do everything,” Mr. Ahlborn says. The Hyperloop “is a first for a lot of things.”

For more from Catherine, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.



Page 1 of 2612345...1020...Last »