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Coal Mine Impoundment Inspection Training. Conducted By: Tri-State Safety Training Services Uniontown, PA 15401 724-439-2601. VISUAL INSPECTION OF EMBANKMENT DAMS. WHAT YOU NEED TO KNOW TO INSPECT AN EMBANKMENT DAM, AND FILL OUT A REPORT OF YOUR INSPECTION. WHAT WE’LL COVER:.
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Coal Mine Impoundment Inspection Training Conducted By: Tri-State Safety Training Services Uniontown, PA 15401 724-439-2601
VISUAL INSPECTION OF EMBANKMENT DAMS WHAT YOU NEED TO KNOW TO INSPECT AN EMBANKMENT DAM, AND FILL OUT A REPORT OF YOUR INSPECTION
WHAT WE’LL COVER: • BASIC DEFINITIONS • FEATURES OF A DAM; CONTROL FEATURES • DEFICIENCIES - POSSIBLE PROBLEMS • SEEPAGE, MOVEMENT, BLOCKAGE OF CONTROL FEATURES, EROSION, FIRE • INSPECTION ROUTE AND REPORT • COMMON INSTRUMENTATION • PIEZOMETERS, WEIRS, STAFF GUAGES, MONUMENTS • REGULATIONS
BASIC DEFINITIONS • DEFINITION OF AN EMBANKMENT DAM • CONFIGURATIONS • FEATURES OF AN EMBANKMENT DAM: • 6 MAIN FEATURES: CREST, SLOPE, BENCH, TOE ABUTMENT, GROIN • CONTROL FEATURES: • 4 COMMON CONTROL FEATURES: SPILLWAYS, DECANTS, CUTOFFS, DRAINS • DEFINITION OF LEFT SIDE / RIGHT SIDE
EMBANKMENT DAMS ARE CONSTRUCTED OF SOIL MATERIALS - INCLUDING MINE WASTE & REFUSE
DAMS ARE USED FOR FRESH WATER SUPPLY, OR FOR REFUSE DISPOSAL IN GENERAL, INSPECTION ACTIVITIES ARE THE SAME FOR EITHER USE, BUT THERE ARE SOME DIFFERENCES, THAT WILL BE ADDRESSED IN LATER SECTIONS
OTHER TYPES OF DAMS ARE UNLIKLY TO BE FOUND ON MINING SITES • CONCRETE ARCH • GRAVITY • MASONARY
CROSS VALLEY SIDE HILL DIKED INCISED THESE CONFIGURATIONS ARE BASED ON THE SHAPE OF THE EMBANKMENT WITH RESPECT TO THE SURROUNDING TOPOGRAPHY COMMON CONFIGURATIONS FOR EMBANKMENT DAMS:
CROSS VALLEY THE EMBANKMENT CROSSES AND BLOCKS A VALLEY
SIDE HILL A SIDE HILL IMPOUNDMENT LIES ALONG THE SIDE OF A SLOPE, OR HILL, AND DOES NOT CROSS A VALLEY BOTTOM
DIKED AN ENCLOSED DIKE BUILT ABOVE RELATIVELY LEVEL GROUND
INCISED EXCAVATED BELOW ORIGINAL GROUND LEVEL
COMMON FEATURES OF EMBANKMENT DAMS • CREST • SLOPE • BENCH • TOE • ABUTMENT • GROIN
“CONTROL FEATURES” ARE STRUCTURES DESIGNED TO CONTROL SEEPING OR FLOWING WATER. • SPILLWAY • DECANT • DRAIN • KEYWAY (CUTOFF)
DECANTS ARE STRUCTURES DESIGNED TO MAINTAIN NORMAL POOL ELEVATION
DRAINS ARE DESIGNED TO SAFELY COLLECT & CARRY SEEPAGE OUT OF THE DAM
KEYWAYS ARE DESIGNED TO REDUCE SEEPAGE RATE THROUGH OR UNDER DAM
LEFT SIDE / RIGHT SIDE OF A DAM IS DETERMINED BY VIEWING THE DAM ORIENTED LOOKING DOWNSTREAM
DEFICIENCIES “DEFICIENCIES,” OR “SIGNS OF DISTRESS,” ARE INDICATORS THAT A POTENTIAL PROBLEM IS DEVELOPING WITH THE DAM
UNCONTROLLED SEEPAGE DISPLACEMENT OF EMBANKMENT BLOCKAGE/DAMAGE TO CONTROL FEATURES EROSION FIRE (COAL REFUSE SITES) 5 CATEGORIES OF DEFICIENCIES
TWO TYPES OF SEEPAGE: • CONTROLLED: SEEPAGE THAT IS SAFELY COLLECTED & DISCHARGED OUT DRAIN • UNCONTROLLED: SEEPAGE THAT IS NOT SAFELY COLLECTED & DISCHARGED OUT DRAIN • BY DEFINITION, ONLY UNCONTROLLED SEEPAGE IS A DEFICIENCY • NOT ALL SEEPAGE COMING OUT A DRAIN IS “CONTROLLED”
PLACES TO CHECK FOR SEEPAGE: • DRAIN OUTLETS • TOE AREA • AROUND PIPES THAT COME THROUGH DAM • GROIN DITCHES • SLOPE BELOW POOL • HILLSIDE DOWNHILL OF GROIN • VALLEY BOTTOM BELOW TOE • ADJACIENT VALLEY • PERIMETER OF POOL
EVIDENCE OF SEEPAGE • FLOWING WATER (DUH) • DARKER SPOTS (MOIST) - LIGHTER SPOTS (EVAPORITES) • IRON STAINS • LUSH VEGITATION (MOISTURE) • DYING VEGITATION (MOISTURE CARRIES SALTS OR ACID) • WATER LOVING VEGITATION (CATTAILS) • WINTER - ICE OR MELTING SNOW
RECORDING SEEPAGE IN REPORT • LOCATION • DESCRIBE WITH RESPECT TO SOME FEATURE • MARK ON DRAWING, OR XEROX OF PLAN VIEW • QUANTITY • USUALLY EYE-BALLED IN GPM • PRECISE MEASUREMENT MUCH BETTER • QUALITY • IS SEEPAGE CLEAR, OR IS IT COLORED WITH SOIL PARTICLES (TAN, BROWN, GRAY, BLACK, MILKY, ETC.
CRITICAL SEEPAGE OBSERVATIONS - THINGS YOU DON’T WANT TO SEE • YOU DON’T WANT TO SEE: • LARGE SEEPS • SEEPS THAT INCREASE SIGNIFICANTLY IN SIZE • SEEPS THAT ARE MILKY OR COLORED BY SOIL PARTICLES
DISPLACEMENT OF EMBANKMENT ANY EVIDENCE THAT THE EMBANKMENT HAS MOVED, EITHER AS A WHOLE, OR AS ANY PART WITH RESPECT TO ANOTHER PART
EVIDENCE OF DISPLACEMENT OF EMBANKMENT • CRACKS • BULGES • SCARPS • DEPRESSIONS • MISALIGNMENTS • DISPLACED TREES • SINKHOLES
DISPLACEMENT LEADING TO CRACKING,BULGE, & SCARP • SLIGHT INITIAL MOVEMENT MAY YIELD SMALL CRACKS ON THE CREST, OR ON EITHER FACE. • CONTINUED MOVEMENT MAY YIELD LARGE VERTICAL DISPLACEMENT (SCARPING) WITH CORRESPONDING BULGES DOWNHILL
THREE TYPES OF CRACKING • LONGITUDINAL • LENGTH OF CRACK IS ORIENTED WITH THE LENGTH OF THE CREST • TRANSVERSE • LENGTH OF CRACK IS ORIENTED PERPENDICULAR TO LENGTH OF CREST • POLYGONAL • HONEYCOMB, OR POLYGONAL ORIENTATION OF CRACKS
RECORDING DISPLACEMENT • LOCATION • DISCRIBE LOCATION WITH RESPECT TO DAM FEATURES • MARK ON DRAWING OR PLAN VIEW • TYPE • CRACK, BULGE, DEPRESSION, ETC. • SIZE • LENGTH, WIDTH, DEPTH, ETC. • ORIENTATION • TRANSVERSE, LONGITUDINAL, ETC.
BLOCKAGE/DAMAGE OF CONTROL FEATURES • BLOCKAGE OF, OR DAMAGE TO: • SPILLWAYS • DECANTS • DRAINS
BLOCKAGE OF/DAMAGE TO SPILLWAYS • OPEN CHANNEL: • MATERIAL SLOUGHED INTO SPILLWAY • MATERIAL ABOUT TO FALL INTO SPILLWAY • MATERIAL INTENTIONALLY PLACED IN SPILLWAY • EROISION DAMAGE TO SPILLWAY • INSUFFICIENT EROSION PROTECTION • PIPE: • DAMAGE TO PIPE • DETERIORATION OF PIPE • BLOCKAGE OF PIPE • POTENTIAL BLOCKAGE OF PIPE
BLOCKAGE OF/DAMAGE TO DECANTS: • TRASH RACKS BLOCKED WITH DEBRIS • TRASH RACKS NOT IN PLACE, OR SUBJECT TO DISLODGEMENT • SLOUGHAGE, OR POTENTIAL SLOUGHAGE OF MATERIAL ONTO DECANT INLET • MOVEMENT OF DECANT FOUNDATION • FLOTATION OF DECANT INLET