The webinar will discuss the basics of various non-destructive evaluation (NDE) methods and their applications for investigating dam, spillway and conduit conditions such as freeze-thaw cracking, void, seepage, corrosion of reinforcing, anchor bolts, strength/moduli, and stability. Guidance will be provided as to which NDE methods are useful for diagnosing various conditions of concrete, masonry, earthen and steel materials. The webinar will...

In 1980, Roller Compacted Concrete (RCC) was utilized to construct the Willow Creek gravity dam in Oregon. Since that time, there have been over 200 RCC projects in the United States. With applications such as gravity dams, overtopping protection, buttresses, guide walls at locks, and service spillways, RCC has proven to be a durable and economical solution to difficult engineering problems throughout the US. Internationally, RCC gravity and...

The Webinar consists of two basic parts: • A history of filter design practice including theoretical design considerations • A step-by-step design process with criterion for the design of a critical filter for one example soil type The primary topics covered in the first part of the Webinar are: 1. Early filter designs that addressed only interparticle seepage and piping. 2. The historical research performed by Sherard et al to deve...

Seepage models for earth dam projects require estimates for the coefficient of permeability for each zone in the cross-section. Models also require an estimate of the anisotropy of the permeability in the zone (anisotropy is the ratio of the horizontal to vertical permeability values of the permeability). Computations of drain designs require accurate estimates of the permeability of filter and drainage materials. Empirical estimates provide...

Quality control activities are important during the construction of an earth dam. The quality control program is intended to ensure that the compacted fill meets or exceeds all the specifications for the earth fill in the construction contract. The two primary specifications involve the degree of compaction and the acceptable range of water content for each zone in the compacted fill. This Webinar provides guidance on common pitfalls in the q...

Content & Objectives: The SITES computer program provides engineers with a tool for predicting the formation and progression of a headcut in an auxiliary spillway during a design storm. The predicted performance given by SITES includes the extent and speed of development of a headcut that may develop in the auxiliary spillway. The predicted erosion in the spillway depends on (1) the duration and quantity of design flow through the spillway...

This webinar will provide practical guidance on the selection of soil shear strength parameters for static slope stability analysis. Topics covered include: stress-strain behaviors of cohesionless and cohesive soils and their relationships to strength selection; drained and undrained strengths and their application in stability analysis; the differences between effective stress and total stress analysis methods; loading cases for stability ana...

As dams deteriorate, or as their purpose and benefits diminish, there may come a time when the appropriate action is to decommission the dam. For some dams, this can be a very simple, rapid and inexpensive undertaking. For other dams, it can be a very complex and costly process, requiring years to accomplish. The purpose of this webinar is to provide an overview of recent trends in dam decommissioning in the United States with an emphasis on t...

Cracks are likely to develop in most embankment dams and levees, and not just in those that are poorly constructed. This course will present some of the common conditions that can lead to adverse geostatic stress conditions, cracking, and hydraulic fracturing in embankments. Case histories are used to illustrate various crack-forming mechanisms and potential failure modes associated with embankment cracking. The need for caution when consideri...

Low-level conduits (pipes) through the base of a dam are the most common spillway for small earthen embankment structures. However, the discontinuity caused by the presence of the conduit creates numerous issues that must be addressed during the design and construction of the low-level pipe. This short course will present general design and construction related issues that dam engineers and owners should be aware of when considering a low-leve...