Potential failure modes analyses (PFMA) was first used in dam safety over twenty years ago and although thousands of PFMA workshops have been conducted since it was first introduced, the use and application of PFMAs is still mostly limited to larger federal agencies and occasionally by others on larger projects. PFMA is a tool and a framework to evaluate dam and levee safety. It has fundamentally changed the way many now approach assessing and...

Internal erosion causes about half of all failures of water-retaining earth embankment dams. Similar statistics apply to levees. Internal erosion occurs when the hydraulic loads imposed by water seeping through the pores or flowing through cracks and openings in the soils in embankments and their foundations generate erosive forces sufficient to overcome the resistance to erosion of those soils. The knowledge of internal erosion processes has...

Lawn Lake Dam, located in Rocky Mountain National Park failed suddenly and catastrophically on a sunny day in July 1982, and resulted in over $30 million dollars in damage and the loss of 3 lives. This webinar will explore the history of the dam, construction features responsible for the failure, the failure event and emergency response, the long legal process to assign liability for the failure and the overall impacts to the Town of Estes Par...

The on-demand course is intended to give the participants an understanding of cavitation on chutes and spillways. The course will be introduced with a video of a case study that illustrates some of the fundamentals of cavitation and an explanation of why cavitation causes damage. Following the video, a Power Point presentation will discuss the beneficial effects of aeration on preventing damage due to cavitation. The participants will be guide...

The on-demand webinar will describe the evolution of Prestressed Rock Anchor technology as applied for over 50 years to dams in North America. This evolution will be presented through an analysis of the successive phases of the PTI "Recommendations" documents, which constitute the referenceable standard of care. Special attention will be paid to issues associated with long-term performance and the so called "Legacy Anchors." Five Learning Obje...

This on-demand webinar will start with the most basic seepage concepts and finalize on actual evaluation of piezometric data for earth dams and levees. Simple basic seepage ideas using high graphic illustrations will be the means to teach all concepts in this webinar. Also, numerous difficult concepts will be fully explained using high graphic simple illustrations. For example, course will also provide unique insight into how seepage changes w...

This course is intended to provide guidance on the proper selection and installation of waterstops for hydraulic structures. This course will discuss the various types and applications of waterstops and discuss the necessary design constraints such as site constraints, joint types, head pressures, and concrete clearances and cover. The course will emphasize the need for thorough structure detailing to ensure proper clearances and placement loc...

Analyses of expected seismic performance of earthen dams subject to potential liquefaction hazard are routinely performed for high hazard dams. The State of Practice has increasingly evolved from simplified methods to the use of fully-coupled seismic pore pressure generation and nonlinear seismic deformation analyses (NDA) using either finite difference or finite element analysis frameworks. To evaluate the accuracy and reliability of these ND...

WinDAM software estimates the erosion and breach outflows from overtopping flows and internal erosion flows affecting earthen embankments. This webinar will provide an overview of the WinDAM model and the various inputs needed. The webinar will also cover output from WinDAM. The webinar will target users and designers more than researchers. Five Learning Objectives of This Course: How could overtopping affect my earthen dam? How could internal...

This webinar will review the 1938 construction failure of the upstream slope of Fort Peck Dam, Montana. The failure began at about 1:15 PM on September 22, 1938 as the construction work had progressed to within 20 feet of the final dam crest elevation. One hundred eighty men were working in the area. Thirty four men were injured. Eight men lost their lives, six of whom were never found and are buried somewhere in the dam. As a result of this s...