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...

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...

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...

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...

At a height of 770 feet, Oroville Dam is the tallest dam in the United States. On February 7, 2017, a section of the concrete chute slab of the service spillway at Oroville Dam failed during spillway discharge. Several days later, as the California Department of Water Resources was evaluating and managing discharges through the damaged service spillway during a large rainfall event, the emergency spillway activated for the first time in the pr...

Communication is important in all aspects of dam safety within an organization, with the public, and with the specific owners or stakeholders of a project. Risk communication and stakeholder participation should ensure that (1) responsible and impacted stakeholders will be partners and be afforded the opportunity to participate in decisions that impact them, and (2) communications regarding potential inundation hazard, consequences, and share...

The purpose of this course is to provide a brief introduction into the science of concrete arch dams. The review will touch on design methods used in the past, but primarily focus on the methods used in the current state of the practice. A historical review of construction techniques will be discussed, and how that relates to evaluations and the physical behavior of the structures. The basic loads and loading conditions used for analysis will...

This webinar will review the 2004 failure of Big Bay Dam. A potential failure modes framework was used to make the forensic root-cause assessment based on data and information provided by the State of Mississippi. A detailed timeline of the failure obtained through review of court proceedings will be presented including the appearance of a number of distress indicators, the seriousness of which were not recognized and acted upon by the Owner a...

Dams are inherently vulnerable during rehabilitation construction due to risks such as a weakened/reduced cross section of the structure or reduced flood passage capacity. Successful management of the risks salient to dam construction requires proactive identification, planning, and mitigation by all parties. This 2-hour webinar will examine typical risk categorization with a focus on dam safety during construction, the risk identification and...

This course will present potential failure modes for chute spillways and ways to design these spillways to minimize the potential for failure. 1. Understanding failure modes such as cavitation and hydraulic jacking that can affect chute spillways. 2. How to evaluate potential spillway design and construction details that could lead to failure modes. 3. How to evaluate potential spillway failure mode4. Understanding design details that can hel...