Focus on Civil Works and Engineering
CLEAN CURRENTS 2026
Time: 4:30 PM - 5:30 PM
Day: 9/23/2026
Room Number: Water Power Intelligence Theater
New: Add Sessions to Your Calendar
Interested in this session? Click "Add to My Calendar" and save specific sessions so you don’t miss out. Available for Mobile and Desktop
Calendar Note: Selecting “Add to Calendar” may download a calendar file (.ics) to your device. On mobile, tap the downloaded file to open it in your calendar app. On desktop, open the downloaded file to add the event to your calendar.
This Intelligence Theater block features the following case studies:
Click a case study below to jump to its details:
Validation of Structural Models. What It Is, and How It’s Done
Mitigation of Alkali-Aggregate Reaction (AAR) through Slot Cutting - Lessons Learned from Red Rock Dam
Lower Baker Dam Seepage Control Project
Validation of Structural Models. What It Is, and How It’s Done
Schnabel Engineering, LLC
There is significant confusion over the term “validation” in dam safety engineering. There is no confusion, or disagreement, regarding the need to check calculations and analyses to reduce the risk of error. It is part of our Ethics, “to protect the health, safety, and welfare of the public”. But this is really verification of the process, not validation. So, what is validation? This paper will discuss and provide an example where results from a numerical model were validated.
For this paper the terms will use the definitions summarized below.
• Verification – process of establishing accuracy, confirm
• Validation – action of proving accuracy
Civil Engineers are at a disadvantage compared to many other engineering disciplines. Mechanical and electrical systems typically undergo rigorous testing to observe the behavior and limitations prior to being placed into operation. Civil engineers, however, never really know how strong their design is until it is broken (look at a simple compressive load test on a concrete sample is proof). Dam safety engineers have another problem. Even if physical tests could be performed, most times the size of the structure and the magnitude of load would make testing impractical and prohibitive.
Dam safety engineers that design and analyze large structures have had to rely on “verification” methods because validation techniques were costly or unavailable. Performance Based Evaluation (PBE) tests and analysis techniques now provide a method to measure the physical behavior of large structures and assess the behavior for large loads. The PBE field tests measure the response of the structure for specific loads. The PBE analysis methods calculate physical characteristics from the measured response, such as modal frequencies, and energy attenuation. These structural characteristics are then used to develop numerical models that actually reproduce measured response.
The paper will summarize recent projects that have incorporated PBE techniques to validate numerical models. The steps included in the paper are considered ground-breaking for dam safety engineering, yet the methods have been successfully used in other disciplines such as firefighting, bridge design and analysis, aeronautical and aerospace technologies. The process used resulted in numerical models that reproduce the measured behaviors and had less uncertainty regarding the results. The process also enlightened and educated the engineers, owners, and regulators to better understand the structural behavior, numerical modeling techniques, helped to develop long-term monitoring of performance, and informed risk reduction.
Mitigation of Alkali-Aggregate Reaction (AAR) through Slot Cutting - Lessons Learned from Red Rock Dam
In-Place Machining Company
This presentation explores the application of slot cutting as a structural relief technique to manage AAR expansion and discusses the proven results at Red Rock Dam. This precision method involves strategically cutting vertical slots through the dam’s concrete monoliths to relieve internal stresses and accommodate movement without compromising stability. Field instrumentation, displacement monitoring, and numerical modeling are used to evaluate the stress redistribution and deformation control achieved post-cutting.
Lower Baker Dam Seepage Control Project
Ballard Marine Construction
Lower Baker Dam (Baker Dam) is a 285-foot-tall, 550-foot-long thick concrete arch dam located on the Baker River in Concrete, WA. Operated by Puget Sound Energy as part of the Baker River Hydroelectric Project, the dam forms Lake Shannon, a 7-mile-long reservoir with a total volume of 146,279 acre-feet that feeds two turbines with a total authorized capacity of 109 MW.
A private Joint Venture (Lower Baker Constructors) consisting of Traylor Bros., Inc., Advanced Construction Technologies, Inc., and Ballard Marine Construction, LLC was selected to remediate significant seepage at Lower Baker Dam. The project was delivered under an Early Contractor Involvement (ECI) model, enabling close collaboration among the owner, engineer, and contractor during preconstruction. This approach supported refinement of design concepts, evaluation of value engineering alternatives, permitting activities, and advancement of the access platform design to 100 percent completion.
Contractor investigations included additional ROV operations to establish pre-project seepage locations and flow rates. High-definition multibeam surveys were performed before inspections to identify and remove debris obstructing inspection areas. Data collected was used to determine diver safety requirements and prioritize locations for seepage mitigation performed in the reservoir.
Primary seepage mitigation strategy focused on installation of a 2-line grout curtain immediately upstream of the dam to treat the foundation features. Key elements included site development at both abutments, construction of a 400-foot-long contractor-designed upstream access platform, real-time monitoring during cementitious grouting, and incorporation of bitumen grouting operations. All work was completed while the dam remained fully operational.
Project challenges included protection of environmentally sensitive waterways, unknown subsurface conditions encountered during drilling, high flow zones in the foundation, and workforce constraints in a remote location. These risks were mitigated through proactive planning, adaptive construction strategies, and continuous monitoring, resulting in effective remediation of seepage at a high-hazard dam.
This project successfully addressed a complex geotechnical challenge: mitigating significant seepage through a 285-foot-tall concrete arch dam’s abutments and foundation which had increased to 200 cubic feet per second (cfs). Through the integration of specialized capabilities from each joint venture (JV) partner, the team successfully achieved a difficult engineering milestone by decreasing total seepage to less than 1 cfs.
