Creating Space Underground
MARCH 2019

AJ McGinn, PhD, PE, President/CEO

March 2019 marks Brierley Associates' 20th year of "Creating Space Underground". We thank our clients, employees, project partners, industry colleagues and founding Principals for this success. Our journey began in 1999 when Gary Brierley announced the establishment of Brierley Associates and the opening of our Denver office, led by Gregg Sherry in the first issue of " SubSurfing USA". During the following year, Alan Howard and Jim Smith joined the firm; and I was brought on as "Employee No. 1".

By 2004, Brierley Associates was featured in Tunnel Business Magazine. That year also marked one of the first of many noteworthy projects. Design of the 4,200-ft long, 12-ft diameter New Crystal Springs By-Pass Tunnel for San Francisco Public Utilities was awarded to Brierley Associates in joint venture with Arup.   

By 2008, our first major Design/Build project, Lake Mead Intake No 3 was underway. We again teamed with Arup in a joint venture arrangement to serve as lead designers for Vegas Tunnel Constructors, a joint venture of Impregilo SpA and SA Healy.  In 2015, that project received the Global Tunnel Project of the Year Award and in 2016 the Tunnel Achievement Award for Project Excellence.

Brierley Associates has been fortunate to be at the forefront of many complex and challenging milestone projects such as:
  • 2009: Caldecott Fourth Bore Highway Tunnel linking Alameda and Contra Costa Counties, CA.
  • 2010 New Irvington Water Tunnel and Vargas Shaft in Sunol, CA. At the time of construction, the 41-ft diameter, 115-ft deep Vargas Shaft was the deepest application of unreinforced secant pile temporary excavation support system.
  • 2010: Water Treatment Plant No. 4 Raw Water Intake and Pump Station Shaft for the City of Austin, TX.
  • 2012: Design/Build Twin Box Vehicular Roadway Tunnels for Liberty University in Lynchburg, VA.
  • 2013: 181 Fremont Tower in San Francisco, CA.  The project was a complex support of excavation system for a 60-ft deep basement excavation in the urban core of San Francisco.
  • 2014: Designer of Record for the "Bertha" Access Shaft in Seattle, WA.
  • 2015: Design/Build Single Horizontal Directional Drilling installation of 3,000-ft and 1,200-ft of 54-inch diameter HDPE Forcemain in Miami Beach, FL, which remains a world record for that size pipe.
  • 2017: Design/Build Northeast Boundary Tunnel with Salini-Impregilo-Healy,JV in Washington, DC for DC Clean Rivers.
Since our founding in 1999, Brierley Associates has focused on  constructability, efficiency and practicality to deliver intrinsic recognizable value to our owner, A/E firm and contractor clients.  These are the tenets of our success that will guide us through the next 20 years. During this anniversary year, the forthcoming issues of InDepth will celebrate our clients, partners and staff and their significant contributions to " Creating Space Underground ".

David J. Berti, Senior Consultant

Constructed in 1874-75, San Leandro Lake was renamed Lake Chabot after Anthony Chabot, the water visionary who led construction of the
dam that created the lake, which is situated within Castro Valley. When it was built, the lake was the primary source of water for San Francisco East Bay. Currently this 315-acre reservoir is a controlled recreational area and serves as a standby emergency water supply.

In 1924 the outlet structure was upgraded and in 2016 DMZ Builders was awarded a contract by East Bay Municipal Utility District (EBMUD) to complete a seismic retrofit, which included a major upgrade to the stone and brick masonry outlet structure and its appurtenances.

Kaneohe/Kailua Sewer Tunnel Project
Recognized for Excellence by American Council of Engineering Companies of Hawai'i

Congratulations to Wilson Okamoto Corporation and the Kaneohe/Kailua Sewer Tunnel project team for receiving the Grand Conceptor Award and People's Choice Award from the American Council of Engineering Companies of Hawaii on February 2, 2019. 
The KK Sewer Tunnel project, with a total cost of $375 million, was completed within the allotted schedule and budget. Construction of the 13-ft diameter tunnel, approximately three miles long from the Kaneohe Pretreatment Facility to the Kailua Regional Wastewater Treatment Plant was aligned under the Oneawa Hills.  After tunneling was complete, 126-inch diameter Hobas pipe was placed and the annular space backfilled with foamed grout. Now in service, wastewater from Kaneohe is conveyed to the Tunnel Influent Pump Station, which lifts the wastewater to the plant for treatment.  
Brierley Associates served in various capacities to Southland/Mole JV the tunnel and shaft contractor including: Pre-bid evaluations and bid assistance; design and submittals for temporary works including shaft and tunnel initial support design; tunnel mapping and initial support selection during construction, jet grouting and low-density pipe backfill grout design and implementation, and assistance with contract change management.  

Brierley Associates' staff involved during the total four-year project duration included:  Alan Howard (Principal-in-Charge and Project Manager); Jeremiah Jezerski (Geotechnical and Tunnel Construction Engineer); Greg Van Etten (Tunnel Engineering Geologist); Phil Burgmeier and Mohamed Gamal (3D Finite Element Analysis Modeling), Charles Luxford (Structural Engineer), and Brian Dorwart (Pipe and Grouting Consultant).  During construction Don Painter served as Project Manager for Southland/Mole JV and subsequently joined Brierley Associates as our Honolulu Office Lead after project completion. 

Chicago, IL

NASTT's No-Dig Show is the largest trenchless technology conference in North America, where professionals learn new techniques that will save money and improve infrastructure. The March 17-21, 2019 event offers six tracks and 160 peer-reviewed, non-commercial presentations, including case studies.
Brierley Associates' Nick Strater-Trenchless Practice Leader, Rebecca Brock, Bill Zietlow, Brian Dorwart and Jim Williams authored the presentations summarized below. Rory Ball, Tom Pullen, Nathan Stubley and  Kyle Friedman will also be attending.  

Alternative HDD Construction Method for Ocean Outfall

2018 Project of the Year New Installation Honorable Mention

Authors:  Craig Camp-GHD; Nick Strater-Brierley Associates; Sharron Lynn-City of Rehoboth Beach, DE; Kelvin George-GHD.

Paper Number:  MM-T2-03
The paper will focus on the lessons learned during construction of an offshore pipeline. Project design elements consisted of: pipeline routing, construction alternatives, and regulatory requirements. One of the biggest impacts to the project was the construction schedule, which required winter marine work and placing the system into operation by June 30, 2018. The winter of 2017-2018 was most notable for four nor'easters in March, which directly affected marine construction. Horizontal directional drilling was used to install about 3,800-ft of off shore ocean outfall pipeline. Project challenges were many, including the need to re-drill 1,200-ft of pilot hole.

Engineering Judgement Required to Use Empirical Tunneling Estimating Methods
Authors:  Bill Zietlow-Brierley Associates; Becky Brock-Brierley Associates; Ryan Crum, City and County of Denver Public Works
Paper Number:  WM-T1-02
Estimating microtunneling parameters often involves empirical methods that are correlated to ground conditions by coefficients derived from case histories. These correlations are often developed based on a limited number of case histories. However, tunneling projects occur in a wide range of ground conditions, thus, great care must be exercised when applying these empirical methods. A recent microtunneling project in Denver, Colorado illustrates this point. This project consisted of twin 96-inch diameter microtunnel drives for new storm drains crossing beneath 17 active rail lines. Ground conditions consisted of both clayey and sandy soils, much of it reworked fill from 100 years of rail yard construction activities. Given the limited access, few geotechnical borings  were completed along the tunnel alignments. Methods for estimating tunneling-induced settlement and pipe jacking forces will be summarized in this presentation and compared to data acquired from the project in Denver.
Assessment of Soil and Bedrock Abrasivity for Horizontal Directional Drilling Projects - A Qualitative Approach
Authors:  Nick Strater-Brierley Associates; Danny Crumpton-Inrock Drilling, Inc.; Brian Dorwart-Brierley Associates; Jim Williams-Brierley Associates
Paper Number:  TM2-T2-02
A common risk to Horizontal Directional Drilling projects is tool and equipment wear associated with abrasive soil and bedrock conditions.   Abrasive conditions can significantly reduce drilling and reaming production rates and increase project costs associated with tool and equipment rehabilitation and replacement. This paper presents common bit and reamer wear patterns that may be attributed to abrasive conditions and provides a summary of indicators and testing that may be used to asses both soil and bedrock abrasivity during project planning and design. An abrasivity scale is provided to help quantify relative abrasivity that may be used to anticipate tool and equipment wear and assist with tool selection.

Chicago, IL

Since 1940, the Ground Hog Club has brought together individuals working in the administration, design and construction of subsurface work. The Ground Hog Club's  Annual Dinner Dance was held on  January 26, 2019.  Robb Johnson of Engineering Construction Innovations and Brierley's Alan Howard, Gregg Sherry, Ike Isaacson and Tom Pullen attended the event.

Kanab, UT

Tanner Brown and Sriram Sekar have joined our BIM team led by Jake Koeliker. Tanner recently graduated from the University of Utah with BS in Civil Engineering. He worked with Brierley as an intern over the summer of 2017. Tanner may be contacted in our Kanab, UT office at 435.222.1159 or by e-mail at

Sriram Sekar recently earned his MS Construction Management from the University of Houston and holds an undergraduate degree in Civil Engineering from Anna University, Chennai, India. While pursuing his masters, he started working with the university as a BIM Modeler in the Facilities Planning & Construction Department. Sriram may be contacted in our Kanab, UT office at 435.222.1159 or by e-mail at

Denver, CO

William Shannon has joined our Denver office as a GIS and Civil 3D specialist. He earned a BS in Geographic Information Science from Texas State University and an AA degree in Geography from Austin Community College. Prior to joining Brierley Associates, Mr. Shannon worked at a well-known provider of wireless critical systems and a Texas regional environmental consultancy.
William's skills and experience includes: AutoCAD Civil 3D, ArcGIS, Autodesk Inventor, Trimble Pathfinder Office, remote sensing, environmental science, pedology, geology, fluvial and riparian systems,and ecological remediation.  Currently, Mr. Shannon is in pursuit of  his Geographic Information Systems Professional/Land Surveyor in Training certification. William enjoys hiking, camping, and kayaking.
William can be contacted in our Denver, CO office at 303.703.1405 or by e-mail at

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.

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