2017 E.B. Burwell, Jr. Award

Presented to:

P.L. Johnson
P.L. Johnson

along with
Shires, P.O., and Sneddon, T.P.


“2016, Geologic and Geotechnical Factors Controlling Incipient Slope Instability at a Gravel Quarry, Livermore Basin, California”

Citation by Mike Hart

The E.B. Burwell Jr. Award is given to authors of a paper that advances knowledge concerning principles of the practice of engineering geology. The paper authored by Phil Johnson, Pat Shires, and Tim Sneddon certainly accomplished that feat. Not only is the paper well written and well organized, it has managed to utilize all the components of engineering geology that go into characterizing and solving a complex geotechnical problem. The paper describes the slow deformation of slopes in a gravel quarry that if allowed to continue unabated, could have resulted in catastrophic landsliding. The authors followed a classic approach to their investigation that included research, site characterization, a well-planned subsurface investigation, analysis, and finally, design of a solution to incipient landslide failure. Their careful investigation and analysis prevented what would have likely evolved into a fully developed landslide affecting a nearby residential development. The paper shows what can be accomplished when all the tools of the engineering geologist and geotechnical engineer are brought to focus in solving a difficult geotechnical problem.

top2017 E.B. Burwell, Jr., Award — Response by the Authors

We wish to thank the GSA Environmental and Engineering Geology Division for this honor and Mike Hart for writing the citation for this award. Mike was one of the peer reviewers for our Environmental and Engineering Geoscience paper, and his comments, as well as those of the other peer reviewers and the journal editor, helped to improve the final paper.

We were fortunate to have the opportunity to thoroughly investigate an incipient landslide on a quarry slope within a Quaternary sedimentary basin, the Livermore Basin, in the eastern San Francisco Bay Area. The Livermore Basin is located within the Mount Diablo Fold and Thrust Belt, and the geologic complexities of that area (particularly the folding of fine-grained lacustrine sediments) led us to apply the principles of stratigraphy, structural geology, and hydrogeology to understand the geologic factors controlling slope movement. Together with our geotechnical engineering team, we used the results of this investigation to design mitigation measures to improve the static and seismic stability of the failing slope. These mitigation measures proved to be effective, because we were provided with the opportunity to investigate the site geology using appropriate subsurface investigation methods, including numerous continuously cored deep borings and installation of slope inclinometers and vibrating wire piezometers. The extensive scope of investigation was key to understanding the unique geologic conditions at the quarry site and surrounding area.

A significant part of our work also included detailed slope stability analyses and geotechnical laboratory testing. In particular, the seismic displacement analyses strongly controlled the eventual mitigation design. We were fortunate to have the assistance and guidance of University of California Berkeley Professor Jonathan D. Bray during the slope stability analysis and design process.

An extensive study such as this required help from many people. We wish to acknowledge the many staff members at Cotton, Shires and Associates, Inc., who assisted with numerous field tasks such as monitoring of slope inclinometers and piezometers, logging and inspection during installation of dewatering wells, and inspection and testing during placement of the earth fill buttress. They had a vital role in completion of this investigation and implementation of the mitigation measures that addressed the incipient landslide hazards at the site.