Creating Space Underground
JUNE 2019

Dr. Gary S. Brierley (AKA Dr. Mole)
Founder of Brierley Associates

It is extremely gratifying for me to help celebrate Brierley Associates' 20-year anniversary. Being a part of a start-up firm is always exciting; to say the least - Wishful thinking is great, but if the phone doesn't ring then all is for naught.
In March of 1999, Brierley Associates took a chance and it turned out well.  I was operating out of Boston at that time and Gregg Sherry came on board in April of 1999 with an office in Denver. Alan Howard and Jim Smith joined as partners shortly thereafter and AJ McGinn, Brierley Associates current President joined in September 2000. It is difficult to recall all of the opportunities that we enjoyed during the first few years of our existence, but we were able to keep our cash flow under control and fortunately realized a steady increase in the demand for our services. Our work on the Big Dig and the Braintree-Weymouth and Boston Outfall tunnels was particularly noteworthy.
Over the years, Brierley Associates has been blessed to work on all types of projects, for many different kinds of clients and in every conceivable ground condition. At Brierley Associates we emphasize what it takes to create successful tunneling projects and the key to success is a solid understanding of how the ground will react to your proposed method of tunneling. No other form of construction has such a challenging interface between planning, design, and construction as does tunneling. Every job is different, and every job requires a great deal of good brainstorming in order to get it right.
Twenty years and counting and, looking back, it was "fun" to participate in the process!


North American Tunneling Journal recently interviewed Brierley Associates' Principal and Co-Founder, Gregg Sherry, PE.  

To read the complete interview, click here.

David J. Berti, Senior Consultant

Lake Mead, which supplies 90 percent of Southern Nevada's water, has dropped 110-ft since 2000, a trend that is expected to continue into the foreseeable future. Given the circumstances and the need to have a reliable water supply, Southern Nevada Water Authority (SNWA) developed a plan to construct a third deep-water intake in Lake Mead. The Lake Mead Intake No. 3 project consists of these major components: a deep-water intake riser and inlet structure, an intake tunnel driven beneath the lake and a portion of Saddle Island, a pumping station on Saddle Island, and a pipeline connection to the existing Alfred Merritt Smith WTF.

Learn more

Rebecca Brock, Associate

In 2015, the National Tunnel Inspection Standards (NTIS) were implemented. This is the first standardized program requiring  that all public vehicular tunnels be  inspected, inventoried, and reported on every two years. In the fall of 2018, five additional Brierley personnel successfully passed the required training course. We now have six Nationally Certified Tunnel Inspectors who are located across the United States:
  • Rebecca Brock, PE, PMP, NCTI
  • David Kwietnewski, PE, NCTI
  • Patrick Smith, PhD, PE, GE, NCTI
  • Jarek Trela, PhD, NCTI
  • Greg Van Etten, PG, NCTI
  • Josh Zimmermann, NCTI
Brierley has served in the Colorado Department of Transportation's (CDOT's) tunnel inspection and asset management program with teaming partners Stantec and Gannett Fleming since 2014. This team was recently awarded this same contract, which will extend through 2023. CDOT has 22 State-owned and 11 Local Agency-owned vehicular tunnels, some of the tunnels are unlined or shotcrete-lined with portals and/or approach embankments comprised of exposed bedrock that are vulnerable to geologic hazards. In addition to meeting the requirements of the NTIS, CDOT requires their consultants to have a geologist or geotechnical engineer available to evaluate the structural geology of the tunnel and other geological features that might be encountered.
Brierley's vast knowledge of ground behavior stemming from our nationwide tunnel, geostructural and geotechnical design services plays a vital role in evaluating the complex geology that can be encountered in tunnels constructed in rock. If you would like to know more about Brierley Associates Nationally Certified Tunnel Inspectors and how we might be able to help your team, please contact Rebecca Brock in our Denver Office at 303-703-1405.

Chicago, IL

Every two years, industry leaders and practitioners from around the world ga ther at the Rapid Excavation and Tunneling Conference (RETC), the authoritative program for the tunneling profession, to learn about the most recent advances and breakthroughs in this unique field. The event will be held June 16 - 19, 2019 in Chicago, Illinois at the Hyatt Regency Chicago.

Brierley's Rory Ball (
Session Co-Chair for Ground Support and Final Lining), Tom Pullen, Ike Isaacson, Don Wotring, Gregg Sherry, Alan Howard, Sean Harvey, Nancy Nuttbrock, Dave Sackett, Seth Hoffman and Ashok Stanley will be attending the conference. 

Big Sky Resort, Montana

Look for Brierley Associates at the  American Society of Mining and Reclamation (ASMR) Annual Meeting, June 3 to 7, 2019, at the Big Sky Resort in Montana. This conference focuses on the research, technical, and regulatory issues associated with the land and water implications of anthropogenic land disturbances. It will provide a forum for the dissemination of information through presentation of research findings, field tours, and open discussion of public policy relating to the applied science of reclamation, rehabilitation, remediation, and restoration of areas disturbed by mining, oil and gas, conventional and alternative energy production, contaminated sites, agriculture, road construction, large-scale commercial development, and other disturbances to land and water resources.
Brierley's Abandoned Mine Lands Sector Leader Dr. Mohamed Gamal along with, Dave Hibbard and Robert Mascarenas will be attending and exhibiting at the conference.  Please stop by Booth #14 and discuss how Brierley can help with your next project.

Denver, CO

Amr Ewais, PhD, P.Eng

Brierley Associates welcomes Amr Ewais to the Denver, Colorado office. Amr is a registered Professional Engineer in the Province of Ontario, CA and has more than 14 years of experience in geotechnical, geoenvironmental and structural engineering. He joined Brierley from the University of California Berkeley where he worked as a research associate for two years. Amr earned his PhD in geotechnical and geoenvironmental engineering from Queens University, Kingston, ON, Canada. He earned his M.Sc. in tunneling and B.Sc. in civil engineering from Ain-Shams University, Cairo, Egypt. Amr has authored or co-authored fifteen industry papers on the use and characteristics of HDPE geomembranes. His geotechnical engineering expertise ranges from: infrastructure monitoring (using fiber optics), post-grouted shafts , contaminant transport, slope stability; and, structural analysis and design.

Amr may be contacted at our Colorado Boulevard Office 303.483.2899 or by email at .

Anna Crockford, P.Eng
Brierley Associates welcomes Anna Crockford to our Denver, Colorado office. Anna has 8 years of geological engineering experience, primarily with Mine Design and is a registered Professional Engineer in the Provinces of Ontario and Alberta. She has worked on a wide variety of geotechnical engineering problems in the mining sector (underground and open pit) and heavy civil project including dams, foundations, and tunnels. Anna has expertise in rock mechanics, excavation and support design, 2D and 3D numerical modeling of geomaterials, natural and engineered slopes, and underground excavations. Anna earned a Bachelor of Science in Geological Engineering and Master of Applied Science in Geomechanical Engineering from Queen's University in Kingston, ON, Canada. Anna has authored and co-authored a dozen industry papers and presentations on geomechanics, rock support and tunneling.
Anna may be contacted in our Broadway Office 303-446-6642 or by email

Bill Zietlow, Senior Associate

Kyle Friedman demonstrating how to log soil samples to high school students.
At one point, most of us engineers and geologists, were not yet engineers or geologists. Some of us didn't find our calling until relatively late in life, even after our first university or work experiences. To help students who are thinking about careers in civil engineering, Brierley's Denver office joined with Denver Public Schools to offer a mentoring program to high school juniors who want to explore more about our profession. This semester, three students from Cole and College View High Schools had the opportunity to learn from Geotechnical Engineers Bill Zietlow and Kyle Friedman.

Bill and Kyle introduced the students on how infrastructure projects start with initial concepts and design followed by: engagement of consulting engineers and geologists to further assess project requirements and, surficial and subsurface characteristics; development of design drawings and bid documents. The students also learned about the role that engineers and geologists fill during construction. This all sounds rather dry, so to bring some realism to the learning process, Bill and Kyle arranged for the students to visit one of our ongoing projects sites to see how highway construction is organized and how soil nail retaining walls are built.

One of the objectives of Brierley's mentoring program is "learn by doing". Each of our students learned basic spreadsheet calculation skills that they applied to a design project. Sebastian and Emily reduced push data from a recent guided auger bore tunnel and compared the resulting loads with two different predictive models. They found good agreement with both models and also noticed a change in load rate in the middle of the drive, suggesting a change in geology. Brandon analyzed soil nail proof tests from one of our retaining wall projects in Austin, Texas to see if the measured bond strength agreed with the value assumed for design.

Upon completion of the program, they each shared their learning experience and project work with their teachers and classmates through a career day poster presentation at their respective schools.

Thank you Emily, Brandon and Sebastian for spending some time with Brierley Associates, we wish success upon each of you during your senior year and in selecting a satisfying career path.

Our Core Purpose

Brierley Associates delivers intrinsic, recognizable value to our owner, A/E firm, and contractor clients by focusing on constructability, efficiency and practicality.  Our geotechnical and structural design and consulting services are founded on a keen understanding of our clients' needs, subsurface conditions, site-specific constraints, and the risks associated with the construction of tunnels, underground facilities and heavy civil infrastructure projects.

                  Creating Space Underground - Coast to Coast