BLOG

Karst and Cave RSS news feed Like us on Facebook! follow us on Twitter!
Community news

Speleology in Kazakhstan

Shakalov on 11 Jul, 2012
Hello everyone!   I pleased to invite you to the official site of Central Asian Karstic-Speleological commission ("Kaspeko")   There, we regularly publish reports about our expeditions, articles and reports on speleotopics, lecture course for instructors, photos etc. ...

New publications on hypogene speleogenesis

Klimchouk on 26 Mar, 2012
Dear Colleagues, This is to draw your attention to several recent publications added to KarstBase, relevant to hypogenic karst/speleogenesis: Corrosion of limestone tablets in sulfidic ground-water: measurements and speleogenetic implications Galdenzi,

The deepest terrestrial animal

Klimchouk on 23 Feb, 2012
A recent publication of Spanish researchers describes the biology of Krubera Cave, including the deepest terrestrial animal ever found: Jordana, Rafael; Baquero, Enrique; Reboleira, Sofía and Sendra, Alberto. ...

Caves - landscapes without light

akop on 05 Feb, 2012
Exhibition dedicated to caves is taking place in the Vienna Natural History Museum   The exhibition at the Natural History Museum presents the surprising variety of caves and cave formations such as stalactites and various crystals. ...

Did you know?

That outlet cave is a cave developed at the point of re-emergence of an underground karst watercourse [19].?

Checkout all 2699 terms in the KarstBase Glossary of Karst and Cave Terms

BLOG on Speleogenesis.info < See all Blog posts
Cave Collapse Evolution Graduate Student Research Positions
johnny.lyonsbaral on 04 Jun, 2013

Limestone Cave Collapse Evolution As An Analog for Long-Term Rock Behavior

Abstract

Long-term rock behavior is important for understanding the degradation and failure of rock slopes, underground excavations, dam and bridge foundations, national monuments, and other critical rock structures. Natural underground caverns are an ideal geologic analog for studying long-term rock behavior, because of the relatively constant climate and the preservation of rockfalls that accumulate on the floor of the cave over thousands of years.  In this study, the evolution of rock degradation and failure in the Kartchner caverns in southern Arizona will be investigated, using a unique combination of radiometric dating and state-of-the-art geomechanics techniques.  First of all, to date the evolution of rockfall that has occurred in the cave over the last 100,000 years, both U-TH and Carbon dating will be used.  Because Kartchner is a live cave, speleothems occur on many of the rockfall blocks, and small cores will be taken at the base of these speleothems for dating.  Secondly, a new generation ground-based LIDAR scanner will be used to obtain detailed three-dimensional point clouds of the cavern geometry and also of the rockfall fragments on the floor of the cave.  The detailed point clouds along with the radiometric data will be used to reconstruct the cave geometry over the past 100,000 years. Finally, three-dimensional modeling will be conducted using the Abaqus finite element program. A time-dependent damage model based on subcritical crack growth will be implemented in Abaqus to simulate cave collapse evolution. Seismic loading of the cave will also be considered, since southern Arizona is susceptible to small to medium levels of seismic hazard.

Kartchner caverns provides a unique opportunity to understand long-term rock behavior, and the results should be of great interest to rock mechanics scientists and engineers as well as karst and cave specialists.  The results of this research will be used to develop and validate long-term strength models or subcritical crack growth models to correctly predict long-term rock behavior.  Kartchner caverns is also an ideal platform to communicate geomechanics to the general public, with public access to 2.4 miles of passages and attracting over 150,000 visitors each year.  As part of this research, an interactive geomechanics display case will be established in the Kartchner visitor center, and cave tour guides will provide geomechanics information on their daily tours.  The results of this research will hopefully provide new findings in the areas of cave breakdown and sinkhole development.  The results of this research might reveal the timing of past seismic events in southern Arizona, and therefore will be of interest to seismologists and also geologists studying Quaternary faulting. 

Student Solicitation

We are seeking graduate students to take on the research presented above.  Up to 3 years of NSF funding is available for either Masters or PhD students interested in participating in this Karst Geology and Geomechanics project.  Applicants need not have a prior degree in either Geological/Geotechnical Engineering or Geology, but strong understanding and interest in karst geology, rock mechanics or hydrogeology are desired for these positions.  If you believe you have the skills and passion to significantly contribute to this project, please call or email as soon as possible to the contact listed below.  Start dates may be possible as soon as Spring 2014.

John Kemeny, PhD

University of Arizona Department of Mining and Geological Engineering

Mines Building, Room 21

1235 E. James E. Rogers Way

Tucson, AZ 85721-0012

kemeny@email.arizona.edu

520-621-4448

You need to be logged in in order to post replies in this BLOG

Please use this pop-up Login Form to enter your member details. This page will reload automatically and you will be able to post reply.

If you are not yet a member of Speleogenesis and want to register please proceed to this page