Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




SHAKE AND BLOW
Ground-improvement methods might protect against earthquakes
by Emil Venere for PU News
West Lafayette IN (SPX) Mar 24, 2014


Researchers are using T-Rex, a 64,000-pound shaker truck, in research to increase the resilience of homes and low-rise structures built on top of soils prone to liquefaction during strong earthquakes. T-Rex is based at a University of Texas at Austin facility that is part of the George E. Brown Jr. Network for Earthquake Engineering Simulation (NEES), a distributed laboratory with 14 sites around the United States. Image courtesy NEES photo.

Researchers from the University of Texas at Austin's Cockrell School of Engineering are developing ground-improvement methods to help increase the resilience of homes and low-rise structures built on top of soils prone to liquefaction during strong earthquakes.

Findings will help improve the safety of structures in Christchurch and the Canterbury region in New Zealand, which were devastated in 2010 and 2011 by a series of powerful earthquakes. Parts of Christchurch were severely affected by liquefaction, in which water-saturated soil temporarily becomes liquid-like and often flows to the surface creating sand boils.

"The 2010-2011 Canterbury earthquakes in New Zealand have caused significant damage to many residential houses due to varying degrees of soil liquefaction over a wide extent of urban areas unseen in past destructive earthquakes," said Kenneth Stokoe, a professor in the Department of Civil, Architectural and Environmental Engineering.

"One critical problem facing the rebuilding effort is that the land remains at risk of liquefaction in future earthquakes. Therefore, effective engineering solutions must be developed to increase the resilience of homes and low-rise structures."

Researchers have conducted a series of field trials to test shallow-ground-improvement methods.

"The purpose of the field trials was to determine if and which improvement methods achieve the objectives of inhibiting liquefaction triggering in the improved ground and are cost-effective measures," said Stokoe, working with Brady Cox, an assistant professor of civil engineering. "This knowledge is needed to develop foundation design solutions."

Findings were detailed in a research paper presented in December at the New Zealand - Japan Workshop on Soil Liquefaction during Recent large-Scale Earthquakes. The paper was authored by Stokoe, graduate students Julia Roberts and Sungmoon Hwang; Cox and operations manager Farn-Yuh Menq from the University of Texas at Austin; and Sjoerd Van Ballegooy from Tonkin and Taylor Ltd, an international environmental and engineering consulting firm in Auckland, New Zealand.

The researchers collected data from test sections of improved and unimproved soils that were subjected to earthquake stresses using a large mobile shaker, called T-Rex, and with explosive charges planted underground. The test sections were equipped with sensors to monitor key factors including ground motion and water pressure generated in soil pores during the induced shaking, providing preliminary data to determine the most effective ground-improvement method.

Four ground-improvement methods were initially selected for the testing: rapid impact compaction (RIC); rammed aggregate piers (RAP), which consist of gravel columns; low-mobility grouting (LMG); and construction of a single row of horizontal beams (SRB) or a double row of horizontal beams (DRB) beneath existing residential structures via soil-cement mixing.

"The results are being analyzed, but good and poor performance can already be differentiated," Stokoe said. "The ground-improvement methods that inhibited liquefaction triggering the most were RIC, RAP, and DRB. However, additional analyses are still underway."

The test site is located along the Avon River in the Christchurch suburb of Bexley. The work is part of a larger testing program that began in early 2013 with a preliminary evaluation by Brady Cox of seven potential test sites along the Avon River in the Christchurch area.

The 64,000-pound T-Rex, operated by NEES@UTexas at UT Austin, is used to simulate a wide range of earthquake shaking levels. NEES is a shared network of 14 experimental facilities, collaborative tools, centralized data repository and earthquake simulation software, all linked by high-speed Internet connections.

.


Related Links
Cockrell School of Engineering
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





SHAKE AND BLOW
Strong quake strikes off Chile
Santiago (AFP) March 23, 2014
A 6.0-magnitude earthquake struck off Chile's northwestern coast on Sunday, the latest of at least seven quakes to hit the region in recent days. About 25,000 homes south of the city of Iquique, on Chile's Pacific coast, suffered a 30-minute blackout, the national emergency office said, but there was no significant damage and no tsunami. The undersea quake hit at 1820 GMT and had a depth ... read more


SHAKE AND BLOW
Up to 18 unaccounted for in deadly US landslide

Safety lapses rapped after US nuclear plant fire

Contaminated Fukushima water may be dumped as problems mount

Fukushima: three years on and still a long road ahead

SHAKE AND BLOW
Pushing and pulling: Using strain to tune a new quantum material

Lightweight Construction Materials of Highest Stability Thanks to Their Microarchitecture

Oregon physicists use geometry to understand 'jamming' process

It looks like rubber but isn't

SHAKE AND BLOW
World Bank approves $73 mn for DR Congo hydro project

Bangladesh's otter fishing tradition faces extinction

World faces 'water-energy' crisis: UN

Deep Ocean Current May Slow Due to Climate Change

SHAKE AND BLOW
Back to life after 1,500 years

Permafrost Thaw Exacerbates Climate Change

The Frozen Truth about Glaciers, Climate Change and Our Future

NASA's Operation IceBridge Begins New Arctic Campaign

SHAKE AND BLOW
Stanford professor maps by-catch as unintended consequence of global fisheries

Ancient clam gardens nurture food security

Research reveals true value of cover crops to farmers, environment

Study examines pesticide poisoning of Africa's wildlife

SHAKE AND BLOW
Ground-improvement methods might protect against earthquakes

Earthquakes Caused by Clogged Magma a Warning Sign of Eruption

Strong quake strikes off Chile

Torrential rains kill 32 in South Africa in two weeks

SHAKE AND BLOW
Chinese nationals held in Nigeria for illegal fishing

Peacekeepers seize large weapons cache in C. Africa

French kill jihadist commander in Mali

What sculpted Africa's margin?

SHAKE AND BLOW
New stratigraphic research makes Little Foot the oldest complete Australopithecus

Eyes are windows to the soul -- and evolution

Stirring the simmering 'designer baby' pot

Empathy chimpanzees offer is key to understanding human engagement




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.