The Horizontal Directional Drilling (HDD) industry has experienced tremendous growth over the past several decades, making HDD a commonplace method for trenchless installation. In this lecture, Dennis will introduce his “3 G’s”—Geometry, Geology, and Geography”—as a framework for understanding HDD design, construction, and project management. The lecture will review some of the earliest applications of HDD, including major river crossings, and trace the evolution of HDD into its many modern applications. Today, HDD is widely used for installing gas, water, and sewer mains; communications and electrical conduits; and a variety of chemical pipelines. These applications extend beyond river crossings to highway crossings and rights-of-way through developed areas, allowing infrastructure to be installed while minimizing disruption to streets, driveways, businesses, and other existing facilities. Topics covered will include HDD equipment and tooling, fundamental design principles, hydrofracture estimation methods, construction considerations, and other factors essential to the successful planning and execution of HDD projects. The lecture will provide participants with a practical understanding of the technical and field considerations involved in designing, constructing, and managing HDD installations.
Speaker: Dennis J Doherty, P.E., BC.PLW, F.ASCE, Senior Consultant – Trenchless Technologies, Geotechnical Design and Instrumentation Services, Terracon
Dennis is a versatile principal engineer with proven experience and is recognized nationally as a leader in trenchless technology. With more than 40 years of industry experience, the last 30 of which have been focused on design, construction, and management of underground infrastructure through application of trenchless technologies, including pipe bursting, microtunneling, auger boring, pipe jacking, pilot tube method, and horizontal directional drilling, he applies a “think outside the box” approach to his projects.
Doherty has been a member of the North American Society for Trenchless Technology (NASTT) since 1992 and has been instrumental in advancing trenchless technology for the industry. He is also a Fellow of the American Society of Civil Engineers (ASCE) and, as one of several principal authors, he contributed to the ASCE Standard Construction Guidelines for Microtunneling and Pilot Tube Methods. He also led a joint task force to revise the standards and add a section on trenchless methods for Gravity Sanitary Sewer Design and Construction.
Registration deadline: Tuesday, October 27, 2026
Registration information: Register to attend this meeting and pay by credit card online by clicking Register. To register online for an event at the BSCES member rate you must login or enter the email associated with your ASCE membership. Cancellations received after October 27, 2026, and no-shows will be billed.