U.S. Fish & Wildlife Service Low Hazard Dams - Association of State ...

damsafety.org

U.S. Fish & Wildlife Service Low Hazard Dams - Association of State ...

STANDING OPERATING PROCEDURESProblemInspection Guidelines – Concrete Upstream SlopeProbable Cause andPossible ConsequencesRecommended ActionsShortened seepage path or increasedstorage levels.1. Higher velocity flows can causeerosion of drain, thenembankment materials.2. Can lead to piping failure.Concrete deteriorated fromweathering. Joint filler deterioratedor displaced. Soil is eroded behindthe face and caverns can be formed.Unsupported sections of concretecrack. Ice action may displaceconcrete.Soil loses its moisture and shrinks,causing cracks. Note: Usuallylimited to crest and downstreamslope. Heavy rains can fill cracksand cause small parts ofembankment to move along internalslip surface.1. Accurately measure outflowquantity and determine amount ofincrease over previous flow.2. Collect jar samples to compareturbidity.3. If either quantity or turbidity hasincreased by 25%, a qualifiedengineer should evaluate thecondition and recommend furtheractions.RDSO NOTIFICATION REQUIRED1. Determine cause. Either patchwith grout or contact engineer forpermanent repair method.2. If damage is extensive, a qualifiedengineer should inspect thecondition and recommend furtheractions.RDSO NOTIFICATION REQUIRED1. Monitor cracks for increases inwidth, depth , or length.2. A qualified engineer shouldinspect condition and recommendfurther actions.RDSO NOTIFICATION REQUIREDRevision No. 0B-17 October 2008

More magazines by this user
Similar magazines