Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Geofoam Protects Pipelines From Earthquakes

04.10.2012
Lightweight and stiff as a board, a plastic foam material is being used to protect Utah’s natural gas pipelines from rupturing during earthquakes.

“If an earthquake occurs, high-pressure gas lines are one of the most important items to protect,” says Steven Bartlett, associate professor of civil engineering at the University of Utah. "If they rupture and ignite, you essentially have a large blowtorch, which is catastrophic.”

Bartlett has partnered with natural-gas company Questar to use large expanded polystyrene blocks called “geofoam” as a compressible, protective cover for natural gas pipelines buried underground.

“This low-impact technology has an advantage in urban environments, particularly if you need to realign already buried structures such as gas lines or utilities without affecting adjacent buildings or other facilities,” says Bartlett.

Geofoam has been used for decades in Europe, North America and Asia to lighten loads under roads and reduce settlement. One-hundredth the weight of soil with similar strength, geofoam blocks reduce construction time and don’t erode or deteriorate.

Bartlett previously researched the design and use of geofoam as a lightweight road embankment in the Interstate-15 reconstruction project through the Salt Lake Valley a decade ago, and more recently in the TRAX light rail line that opened last year to serve West Valley City, Utah. Geofoam currently is being used in the TRAX extension to the airport.

Questar – which provides natural gas to almost 900,000 customers in Utah, southwestern Wyoming and southeastern Idaho – is using geofoam in lightweight covers for minimizing damage to natural gas pipelines caused by severe earthquakes.

“Most pipelines are designed to withstand some ground shaking, but not several feet of sudden fault offset that may occur in a major earthquake,” says Bartlett. “When a fault breaks, it occurs in milliseconds. It is an extreme event. The problem Questar faced was, how could a buried pipeline survive that offset?”

Geologists expect that when a major earthquake strikes the Wasatch fault zone in the Salt Lake Valley, a fault rupture likely will make the valley drop down relative to the mountains. As the valley drops down, a buried pipeline would start to lift up. However, most buried pipelines lie under six to eight feet of compacted soil. This weight becomes too much for a pipe to bear, causing it to rupture, Bartlett says.

Numerical simulations of earthquake fault ruptures performed by Bartlett and his students show a geofoam-protected pipeline on the valley side of the Salt Lake City segment of the Wasatch fault could withstand up to four times more vertical force than traditional soil cover.

Based on Bartlett’s experience with geofoam, Questar asked him to develop a strategy for protecting buried pipelines crossing earthquake faults in urban areas, such as 3300 South, an arterial street in the Salt Lake Valley.

“In this situation, we had to put the pipeline right down the center of the roadway. When we looked at what other countries did, they built a trapezoidal geometry above the pipe—basically just a wedge,” says Bartlett.

Such a wedge would require many blocks of foam and would disrupt a large section of road, Bartlett says. “This would be a major problem in an urban area, as you might have to tear up 20 feet of lateral roadway. Try to do that for 3300 South – you’d have to shut the whole road down.”

Rather than gut a major thoroughfare, Bartlett proposed a “slot trench” design in which a block of geofoam is placed in a narrow trench between a pipeline and the pavement above. In this design, if the pipeline begins to lift up, it will displace the geofoam block and compress it. Although geofoam is solid, it contains tiny air pockets that can compress without sacrificing the material’s overall integrity. As the geofoam is compressed further, it will slide upward along the trench sidewalls and could eventually damage the pavement above. However, says Bartlett, the pipeline will remain intact and essentially undamaged.

Since the 3300 South project, Questar has been installing geofoam to protect other natural gas pipelines in the valley.

In addition, Bartlett and colleagues at the University of Memphis and University of Illinois at Urbana-Champaign are investigating geofoam to help new buildings withstand earthquakes. When a building shakes during an earthquake, says Bartlett, soil adjacent to the building puts additional pressures on its walls as it tries to move back and forth.

By placing a geofoam buffer between a building’s walls and neighboring soil, it can sway without experiencing additional pressures. The geofoam, which deforms in a controlled manner when placed against a structure, can reduce earthquake pressures by 30 to 50 percent, according to Bartlett’s calculations. This also reduces the amount of steel and reinforcing concrete needed to protect the building from earthquake damage.

Compared with compacted soil, geofoam is competitive when total construction costs are considered, Bartlett says. What’s more, geofoam requires typical road embankment construction times of one month, compared with 12 to 15 months using traditional methods.

“When there are sensitive utilities involved, seismic stresses or time is a factor, this technology wins hands down,” says Bartlett.
Contacts:
--Steven Bartlett, professor of civil engineering – office (801) 587-7726, cellular (435-841-9837), bartlett@civil.utah.edu

-- Aditi Risbud, senior communications and marketing officer, College of Engineering – office (801) 587-9038, cellular (213) 400-5815, aditi.risbud@coe.utah.edu

University of Utah College of Engineering
72 S. Central Campus Dr., Room 1650 WEB
Salt Lake City, UT 84112
(801) 581-6911 fax: (801) 581-8692

Aditi Risbud | Newswise Science News
Further information:
http://www.coe.utah.edu

More articles from Earth Sciences:

nachricht New insights into the ancestors of all complex life
29.05.2017 | University of Bristol

nachricht A 3-D look at the 2015 El Niño
29.05.2017 | NASA/Goddard Space Flight Center

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

Reptile vocalization is surprisingly flexible

30.05.2017 | Life Sciences

EU research project DEMETER strives for innovation in enzyme production technology

30.05.2017 | Power and Electrical Engineering

New insights into the ancestors of all complex life

29.05.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>