Reclamation Information Sharing Environment (RISE)

Voids form as a consequence of the deteriorated state or poor design of the structures they are associated with. There are a variety of different mechanisms that can lead to the formation of voids adjacent to dam structures (U.S. Bureau of Reclamation, 2019). Determining the appropriate action to be taken after a void has been detected involves the careful consideration of many different factors. Selection of the appropriate method is always site specific. Designers must consider factors such as the type of materials used in the original design as well as common design / construction practices at the time of construction. Some other important factors include downstream impacts, extent and location of damage, size and shape of conduit or spillway adjacent to the void, type of material being eroded, size of dam, and cost of repair. This report details each of the different repair, renovation, and replacement techniques for structures associated with void formation, and provides guidance on the appropriate action to be taken. Additionally, the report provides the results of laboratory testing on permeable low density cellular concrete and foam transported sand as innovative methods to repair voids.