“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
Study relating to materials testing Detecting damages in non-magnetic steel through magnetism
23.07.2018 | Technische Universität Kaiserslautern
Innovative genetic tests for children with developmental disorders and epilepsy
11.07.2018 | Christian-Albrechts-Universität zu Kiel
There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.
The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...
New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference
Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...
Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...
Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.
When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...
Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.
Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....
17.08.2018 | Event News
08.08.2018 | Event News
27.07.2018 | Event News
20.08.2018 | Information Technology
20.08.2018 | Life Sciences
20.08.2018 | Information Technology