Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ground Motion Study May Show Need to Modify Building Codes

06.12.2011
“In recent decades, population growth and scarcity of undeveloped metropolitan land have changed urban land use patterns and placed an increasing number of people and infrastructure in areas susceptible to topographic effects during earthquakes,” said Adrian Rodriguez-Marek, associate professor of civil and environmental engineering at Virginia Tech.

“A major impediment towards understanding and realistically modeling topographic effects has been the lack of a statistically significant number of seismic recordings from densely instrumented sites with topographic features,” Rodriguez-Marek added.

New testing conducted in a steep, mountainous region of Utah, using mining induced events, is providing a new set of data necessary for better predictions.

The testing is part of a large National Science Foundation funded project involving five institutions across the United States, with Rodriguez-Marek of Virginia Tech serving as the principal investigator. This project focuses on increasing the understanding of the effects of surface topography on earthquake ground motions and seismic risk. The goal of the project is to develop design-ready tools to account for the effect of topography on ground motions.

In addition to Virginia Tech, the University of Washington, Georgia Tech, the University of Arkansas, and the University North Carolina at Charlotte are also participants. The project uses the Network for Earthquake Engineering Simulation (NEES) equipment sites at the University of California at Davis and at the University of Texas at Austin.

The first recordings included more than 50 mining-induced seismic events. Researchers from the University of Arkansas and the University of Texas at Austin gathered this first data.

According to Rodriguez-Marek, when the study is completed, they will have the necessary information to “modify building codes and to improve safety in the building environment.”

Hillsides, ridges, and canyons are examples of sites where researchers do not have current reliable data to know how seismic shaking will be impacted by the ground features.

Although researchers have documented effects through observations of damage and the collapse of structures near the top of steep hills or ridges, “proper quantification of these effects” has not occurred because the areas did not have “densely-instrumented sites to record data,” Rodriguez-Marek explained.

The test site in Utah stood about 2000 feet above the long-wall mining activities of Deer Creek Coal Mine. The researchers placed 13, three-component sensors in a three-dimensional array over the ridge and hillside. Data was collected 24 hours a day for seven consecutive days. The 50 seismic events represented the first phase of a multi-phase project. Additional data will be gathered at the Utah site this summer, and from tests at a geotechnical centrifuge at the University of California at Davis.

“As real earthquakes are infrequent and unpredictable, the shallow and predictable seismic activity induced by the stress relief that results from long-wall mining provides a good source of seismic energy for this study,” Rodriguez-Marek said.

“Preliminary results clearly show higher ground motion intensity near the crest or peak of the slope,” he added. The early data was used to calibrate mathematical models of the effects and to design the second phase of testing that occurred in the summer of 2011. Results are still being processed.

This NSF study includes a new Bridge to the Doctorate Program geared towards increased participation and education of Hispanic students in the field of earthquake engineering.

“We hope to use our approach and collaboration among universities to serve as a model for increasing diversity in large, collaborative science, engineering, and technology research projects. Students from the University of Puerto Rico at Mayaguez have participated in summer studies at the University of Arkansas, and one student is currently enrolled at the University of North Carolina at Charlotte,” Rodriguez-Marek said.

Lynn Nystrom | Newswise Science News
Further information:
http://www.vt.edu

More articles from Studies and Analyses:

nachricht Self-organising system enables motile cells to form complex search pattern
07.05.2019 | Westfälische Wilhelms-Universität Münster

nachricht Mouse studies show minimally invasive route can accurately administer drugs to brain
02.05.2019 | Johns Hopkins Medicine

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

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

Im Focus: The hidden structure of the periodic system

The well-known representation of chemical elements is just one example of how objects can be arranged and classified

The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...

Im Focus: MPSD team discovers light-induced ferroelectricity in strontium titanate

Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.

Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

Uncovering hidden protein structures

18.06.2019 | Life Sciences

Monitoring biodiversity with sound: how machines can enrich our knowledge

18.06.2019 | Life Sciences

Schizophrenia: Adolescence is the game-changer

18.06.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>