Posts about civil engineering

Building a Network of Tunnels Underground to Ease the Flow of Traffic

Guest post by Aron Alba

“Roads must go 3D” – Elon Musk

The Boring company plans to build the network of tunnels under the ground in order to combat traffic congestions all over United States. As seen in their presentation video, the idea is to construct a system of tunnels in which electric vehicles autonomously zip around cars, people and cargo transport in high speed under the surface (like a scene from a science fiction movie).

The ride would begin with the lift that lowers the vehicles from the surface into the tunnel system. These lifts could be a possible bottleneck for the entire system, but it may be the best solution. To secure the vehicle to the autonomous pod and possibly select the end destination would take some time anyways, so this transition into the tunnel system could go unnoticed. Pods could travel at higher speeds than those allowed for the human driver, since the system is autonomous and completely monitored. The scenery wouldn’t be much though, so probably not the most interesting ride, but certainly fast.

Why build a tunnel network in the first place?
Traffic congestion is a very common nuisance in american lives. With the problem just getting worse. In order to solve this problem you have to build more roads or have fewer cars on them with arranging a better public transport. The land for the roads is scarce. The alternative of going up using drones to fly people around may not become possible due to safety concerns in a long time. Where to go then? Underground.

This has not been done before for obvious reasons, it is really expensive. The most expensive roads to build are tunnels and bridges. Tunnels have even more problems the larger they get. With people driving inside of them there needs to be proper ventilation to get rid of the carbon-monoxide. Resting stops for people. Great deal of risk with so many people driving inside a closed tunnel. The subway system is one solution to many of these problems. Except subways lack the flexibility and require substantially more infrastructure.

Elon Musk’s big plan is to use the technology that his other company Tesla already has developed. Instead of trains like in a subway system, Musk plans to have autonomous pods that run on battery power to zip along the tunnels. This has several advantages. First the battery powered pods to not require power lines to be continuously run through the tunnel like the train does, this saves on the costs of the tunnel. Also since the pods will be autonomous, this saves on personnel needed to operate the system. But probably the smartest idea behind the Boring company’s plans is to build a tunnel with a smaller bore diameter. Probably large enough to fit a pod with a largest planned Tesla vehicle but certainly smaller than the current tunnels for trains.

The Boring company plans to build the tunnel network using a tunnel boring machines. These machines are massive systems build to bore tunnels with circular cross section. They consist of cutting head system, a system for removing earth, systems for advancing the cutting head, systems for laying the concrete walls around the bore. At the end these machines leave a tunnel pretty much ready to use.

Continue reading

Hyperloop – Fast Transportation Using a Better Engineering Solution Than We Do Now

Elon Musk (the engineer and entrepreneur behind Tesla electric cars and before that he helped create PayPal) has a very cool idea of how to provide fast long distance transportation (faster than a plane). Essentially it is a big version of pneumatic tubes that used to be used to send small packages around a building, as seen in the movie – Brazil 🙂 Details are scheduled to be released August 12th.

This Is How Elon Musk Can Build the Hyperloop for a Tenth the Cost of High-Speed Rail

Having a elevated Hyperloop main line also completely avoids or reduces many of the pitfalls of ground-level right-of-ways, and opens up some new opportunities as well:

  • The crossing of other right-of-ways, like roads and railways, will be a breeze.
  • Rivers and other terrain obstacles will only be a 10th the problem of rail construction.
  • Hyperloop can avoid tunnels completely by having more flexible choices of right-of-way.
  • An elevated right-of-way opens up new route options, like leasing farmer’s fields using contracts similar to what wind-power companies sign.
  • That could be paid for by leasing Hyperloop’s right-of-way to communications companies for fiber optic cables, cell phone towers, etc.
  • …and let’s not forget the solar power that a couple of square miles of surface area can generate!

Hype Builds Before Elon Musk’s August Alpha Plan for Hyperloop

The Hyperloop would transport passengers from San Francisco to Los Angeles in about 30 minutes and at about twice the average speed of a commercial jet. The system would be on-demand, cheaper than current alternatives, impossible to crash, and potentially, run entirely on solar power.

Travelers ride in pods magnetically accelerated and decelerated into the main tube (like a rail gun) where the air circulates at speed. The air between pods acts as a cushion, preventing crashes, while more air injected through perforations in the tube levitates the pods and reduces friction, much as it might on an air hockey table.

Elon Musk has some very good ideas but what really sets him apart is turning them into functioning enterprises. Great ideas are wonderful but a huge number never go anywhere. Those people that can actually get ideas into the marketplace are the people that provide a much greater standard of living for all of us. And many of them are engineers.

Update: link to his blog post announcement.

More examples of cool extreme engineering: Monitor-Merrimac Memorial Bridge-TunnelTransferring Train Passengers Without Stoppingtransatlantic tunnelWebcast on Machine That Bores Subway Tunnels

Research on Ancient Roman Concrete Will Allow the Creation of More Durable and Environmentally Friendly Concrete

Analysis of samples of ancient Roman concrete pinpointed why the best Roman concrete was superior to most modern concrete in durability, why its manufacture was less environmentally damaging – and how these improvements could be adopted in the modern world.

“It’s not that modern concrete isn’t good – it’s so good we use 19 billion tons of it a year,” says Paulo Monteiro (U.S. Department of Energy’s Lawrence Berkeley National Laboratory). “The problem is that manufacturing Portland cement accounts for seven percent of the carbon dioxide that industry puts into the air.”

Portland cement is the source of the “glue” that holds most modern concrete together. But making it releases carbon from burning fuel, needed to heat a mix of limestone and clays to 1,450 degrees Celsius (2,642 degrees Fahrenheit) – and from the heated limestone (calcium carbonate) itself. Monteiro’s team found that the Romans, by contrast, used much less lime and made it from limestone baked at 900Ëš C, or lower, requiring far less fuel than Portland cement.

Cutting greenhouse gas emissions is one powerful incentive for finding a better way to provide the concrete the world needs; another is the need for stronger, longer-lasting buildings, bridges, and other structures. Roman harbor installations have survived 2,000 years of chemical attack and wave action underwater. We now expect our construction to last 50 to 100 years.

The Romans made concrete by mixing lime and volcanic rock. For underwater structures, lime and volcanic ash were mixed to form mortar, and this mortar and volcanic tuff were packed into wooden forms. The seawater instantly triggered a hot chemical reaction. The lime was hydrated – incorporating water molecules into its structure – and reacted with the ash to cement the whole mixture together.

Continue reading

Documentary on 5 Women Majoring in Science and Math at Ohio State

In the clip, Jennifer Jones, a civil engineering student who talks about her challenges and determination to overcome obstacles in her honors program at Ohio State University. The clip is from Gender Chip Project, a documentary following 5 women majoring in the sciences, engineering and math at Ohio State University.

Related: Women Working in ScienceWomen Choosing Other Fields Over Engineering and MathGirls in Science and EngineeringFixing Engineering’s Gender Gap

Monitor-Merrimac Memorial Bridge-Tunnel

photo of Monitor-Merrimac Memorial Bridge-Tunnel photo of Hampton Roads Virginia Bridge-Tunnel

Now that is some cool engineering: a bridge that becomes a tunnel. The Monitor-Merrimac Memorial Bridge-Tunnel is a 4.6 miles (7.4 km) crossing for Interstate 664 in Hampton Roads, Virginia, USA. It is a four-lane bridge-tunnel composed of bridges, trestles, man-made islands, and tunnels under a portion of the Hampton Roads harbor where the James, Nansemond, and Elizabeth Rivers come together in the southeastern portion of Virginia.

If you like this post, please look at our other popular posts, and consider adding our blog feed to your blog reader. Posts such as: Bacteriophages: The Most Common Life-Like Form on Earth, Robot Finds Lost Shoppers and Provides Directions and The Engineer That Made Your Cat a Photographer

It was completed in 1992, after 7 years of construction, at a cost $400 million, and it includes a four-lane tunnel that is 4,800 feet (1,463 m) long, two man-made portal islands, and 3.2 miles (5.1 km) of twin trestle.

Photos by Virginia Department of Transportation. Details from wikipedia. Google satellite view of the bridge-tunnel.

Related: Extreme EngineeringCool Falkirk Wheel Canal LiftThe Dynamics of Crowd Disasters: An Empirical StudyA ‘Chunnel’ for Spain and MoroccoSwiss dig world’s Longest Tunnel

Transferring Train Passengers Without Stopping

The webcast shows a train transferring passengers without stopping. Essentially passenger modules are picked up and dropped off at each station. Looks pretty cool and would seem to require somewhat complex engineering – which can be a problem as complexity allows for more things to go wrong. Still it looks pretty cool. The sound is not in English but you can see what the idea is.

Inventor rolls out efficient non-stop train system

Taking the Kaohsiung MRT system as an example, Peng says that its maximum speed is 85 kph. Because it must stop at every station, it achieves an average speed over its route of just 35 kph. If the non-stop system were in place, the top velocity of 85 kph could be maintained throughout the system, saving time and energy.

via: trains that pick you up without stopping

Related: Extreme EngineeringMIT Hosts Student Vehicle Design SummitDesigning Cities for People, Rather than Cars