The BAPG presents...
When Did the Slope Start Moving…Varved Clays, Pipelines, and Landslides.
Todd G. Bown, P.G. (AL, NY, and PA)
Senior Project Manager, GZA GeoEnvironmental
(1 PDH Credit Available - pending approval)
Abstract -
Following a week of heavy rain, on May 16, 2000, a landslide occurred in the village of Delmar, NY, just outside of the City of Albany. During the landslide, a portion of the slope between Delaware Avenue (Route 443) and Normans Kill failed and moved northwards to Normans Kill creating a 300 ft long and 70 ft deep scarp. The landslide flow carried soil into the Normans Kill, damming it which prompted the City of Albany to relocate that section of the river. Later, on June 10, 2000, the landslide toe failed again and flowed into the relocated Normans Kill while repairs were underway.
Subsequently, debris from the relocated stream channel were removed and more riprap was added to the channel banks.
In May of 2024, a property owner located adjacent to the properties affected by the 2000 landslide reached out for assistance in identifying the current stability state of their right-of-way. At this time, a landslide scarp (tension crack), approximately 140 feet wide with measured displacement between 2 to 6 inches was present within an asphalt parking lot situated above their property.
Initially, the project started with a desktop analysis, involving the review geotechnical data reports from the subsurface investigation conducted by the New York State Department of Transportation (NYSDOT) after the year 2000 landslide. Using the borings, material index and strength data (in-situ and residual shear strength) from 2000 landslide, the slope stability of the property was assessed under several case conditions for global and localized failures. Case models reported factors of safety below one for circular failure along various critical slip surfaces.
This presentation will review the work progress from desktop analysis to the recently completed slope monitoring instrumentation program, and how an instrumentation monitoring plan was developed for the property owner to safely operate their subsurface assets with real-time slope instrumentation data.
Speaker Bio -
Todd Bown has over twenty years of geologic consulting experience and is a Senior Project Manager with GZA GeoEnvironmental. His professional interests include the development and management of geotechnical and geological hazard projects within GZA's energy and water business units. Mr. Bown specializes in dam safety, geotechnical instrumentation, geologic mapping, geologic hazard assessment, kinematic analysis for rockfalls, and stability analysis of slopes. Before GZA, Todd worked for the Palmerton Group, where he was actively involved with the plugging and abandonment of orphaned oil wells and waterflood oil leases within the Appalachian basin for a Fortune 500 energy company. In his early career, Todd started as a drillers helper and worked as a field geologist for a national engineering firm.
Todd is a licensed professional geologist in New York, Pennsylvania, and Alabama. He is also a certified slope access technician through the PCIA, and is approved to drill on high-hazard earthen embankments for FERC and USACE projects. In prior years, he served in several positions on the BAPG board, as well as a director on the NYSCPG board. Todd holds a Bachelor of Science in Geology from Buffalo State and a Master's in Geotechnical Engineering from Missouri Science & Technology.
Important Information & Reminders -
Did you know that the cost is the largest barrier preventing students from attending BAPG meetings? Please consider sponsoring a student's attendance during registration. This gesture can have a long-lasting impact by supporting students beyond the current meeting.
The final headcount for attendance is due the Friday (5/9) before the presentation. Participants will have to pre-register for this event and will not be able to walk in unregistered on the day of the event.
This is our last meeting of the 2024-2025 season. Keep your eyes peeled for additional hiking and social hour opportunities this summer before we reconvene next fall.
