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SPIRAL NAILS FOR REPAIRING BULGING FACE OF WELDED WIRE WALL _________________________________. ITD Project Development Conference Boise, Idaho April 2005 ___________________________________ By Tri Buu, P.E. Geotechnical Engr. Idaho Transportation Dept. SPIRAL NAILS.
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SPIRAL NAILS FOR REPAIRING BULGING FACE OF WELDED WIRE WALL_________________________________ ITD Project Development Conference Boise, Idaho April 2005 ___________________________________ By Tri Buu, P.E. Geotechnical Engr. Idaho Transportation Dept.
SPIRAL NAILS • MICA CREEK BRIDGE WAS CONSTRUCTED IN 2002, ON US-95, SOUTH OF C.D’.ALENE, IDAHO • HILFIKER WELDED WIRE WALLS WERE USED TO CONTAIN THE APPROACH EMBANKMENTS ON BOTH ENDS OF THE BRIDGE. • SOON AFTER THE WALLS WERE CONSTRUCTED, BULGING FACE PROBLEMS DEVELOPED IN SEVERAL LOCATIONS NEAR THE TOP OF SOUTHWEST AND NORTHEAST WINGWALLS, WHICH HAVE A 3 FEET HIGHT GABION WALL SITTING ON TOP OF THEM. IT IS BELIEVED THAT THE PROBLEMS WERE CAUSED BY THE EXCESSIVE VERTICAL SPACING OF WALL BACKFILL REINFORCEMENTS (OVER 3 FEET, WHILE TYPICAL SPACING IS 2 FEET) • THE WALL MANUFACTURER, HILFIKER, WAS CONTACTED REGARDING THESE FACING PROBLEMS AND THEY SUGGESTEDTHAT SPIRAL NAILS BE USED TO CORRECT THE PROBLEM.
SPIRAL NAILS • SPIRAL NAIL IS A HOLLOW NAIL HAVING A SPIRAL SHAPE SHAFT, ABOUT 10 FEET LONG WITH A 5” SQUARE PLATE AT THE END. • THE NAILS WERE DRIVEN THROUGH THE WELDED WIRE WALL FACES AND INTO WALL BACKFILL WITH A HYDRAULIC IMPACT HAMMER. THE HAMMER WAS MOUNTED AT THE BOTTOM OF AN EXCAVATOR’S BUCKET. • THE NAILS WERE DRIVEN IN BETWEEN TWO LAYERS OF WALL BACKFILL REINFORCEMENTS, AT A DOWNWARD ANGLE OF ABOUT 5 DEGREES. NAIL SPACINGS WERE ABOUT 3 FEET. THEY WERE DRIVEN ABOUT 2 TO 3 INCHES INTO THE WALL FACE. COULD BE DRIVEN DEEPER BUT STOPPED TO AVOID POTENTIAL DAMAGES TO WIRES AT WALL FACE. IT TOOK ABOUT 1.5 MINUTES TO DRIVE IN THE 10 FEET LONG NAIL. • MAIN APPLICATION OF NAILS IS TO KEEP THE BULGING PROBLEM FROM GETTING WORSE.
SPIRAL NAILS • BULGED WALL FACE
SPIRAL NAILS • SPIRAL NAILS
SPIRAL NAILS • NAIL END
SPIRAL NAILS • NAIL TIP
SPIRAL NAILS • NAIL SHAFT
SPIRAL NAILS • BEARING PLATE
SPIRAL NAILS • NAIL IN HAMMER
SPIRAL NAILS • POSITION NAIL FOR DRIVING
SPIRAL NAILS • DRIVING NAIL
SPIRAL NAILS • NAILED WALL FACE
SPIRAL NAILS • NAILED WALL FACE
SPIRAL NAILS • SEVERE BULGING WALL FACE
SPIRAL NAILS • DON’T KNOW ????? • PULL OUT CAPACITY OF NAIL • HOW LONG THE NAILS WILL LAST ____________________________________ NEXT IS A VIDEO OF THE NAIL INSTALLATION