$1.25M Project Could Make Mining, Construction Safer

A UA engineering research program into new methods of determining rock strength could reduce hazardous working conditions that currently cause thousands of deaths every year in mining and construction.
January 24, 2012
Pinnaduwa H. S. W. Kulatilake, professor of geological engineering in the UA College of Engineering.

A University of Arizona geotechnical engineer has been awarded $1.25 million to conduct research that could provide safer working conditions for miners and construction workers.


Ground failure is generally any significant movement of the ground, such as a landslide or underground excavation collapse. Or it can happen when the ground moves and flows like liquid, which results when earthquakes or high water pressure cause soil to lose its strength.


Part of the problem is that current methods of rock assessment simply are not up to the task of providing a detailed picture of what engineers are truly getting into when they start blasting and tunneling.

Pinnaduwa H. S. W. "Kumar" Kulatilake, professor of geological engineering in the UA College of Engineering, is the sole principal investigator for a five-year project to develop new methods of assessing ground stability. The National Institute for Occupational Safety and Health, which is part of the Centers for Disease Control and Prevention, is funding the research.

Ground stability depends on the strength and deformability of rock, which in turn depend on:

  •     What type of rock is present and how it behaves under certain conditions
  •     Presence of joints, fractures and faults
  •     Stresses on the rock, such as pressure from overlying rock, or tectonic forces
  •     Groundwater conditions
  •     Stresses and forces present in the rock that will be released by excavation

The relationships among these factors are complex and it is difficult to determine rock strength and deformability, and thus ground stability, using the analysis techniques and limited field and laboratory investigations that are currently available.

During the five-year project, Kulatilake will extend rock strength criteria he has developed to make them applicable in three-dimensions. He will be working with two mines in the U.S. and two mines in China to apply his new methodologies to underground and surface excavations to check how well they work in the real world.

China's official mining death toll in 2010 was 2,631. It is the world's largest coal producer and consumer and employs 5.5 million coal miners.





Another aspect of the problem is that assessing ground stability and preventing ground failure are extremely difficult. Because the number of experts in this area is decreasing, along with funding to train their replacements, a dwindling few remain to conduct these challenging assessments.

In terms of creating a new generation of experts in this area, Kulatilake expects the research to lead to the completion of seven doctoral dissertations.

"We need to have some young blood," he said. "It is time to create a new generation of mining professionals who are experts in ground control."

The research findings will be incorporated in graduate courses that Kulatilake teaches in the department of mining and geological engineering and the department of civil engineering and engineering mechanics. And his teaching will extend beyond the University of Arizona: During the last 20 years, he has taught 52 short courses all over the world.

Overall, Kulatilake expects his research results to provide a wealth of information related to excavations made for mineral extraction, tunnels for hydropower and transport, dams, foundations, natural and man-made slopes, underground caverns for oil and gas storage and human use, and hazardous waste isolation caverns.