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HomeMy Public PortalAboutPrecast Concrete ManholeM.S.D. STANDARD MANHOLE FRAME AND COVER. SET MANHOLE FRAME WITH TWO (2) COMPLETE ROWS OF 1 INCH THICK FLEXIBLE RUBBER MASTIC SEALANT. ADJUST TO GRADE WITH APPROVED GRADE RING. PRECAST RISER SECTION. ROUND RUBBER GASKET JOINT OR APPROVED EQUAL. SHAFT STEPS UNIFORMLY SPACED AT 16" C-C. (* ) SHOULD NOT BE OVER TOP OF PIPES AND SHALL EXTEND 5-1/2" FROM WALL. PRECAST MANHOLE BASE. ELEVATION NOTES: CONCENTRIC PRECAST TOP TRANSITION CONE SECTION, MANHOLES 42-48 INCHES. 42" OR 48" DIA. 7 4" . i /2" 2-1/2"-- BASE SECTION 6"MIN. FOR DROP PIPE, FACTORY CAST OPENING AS REQUIRED. APPROVED PATENTED COMPRESSION TYPE JOINT. PROVIDE AND ADJUST RISER SECTIONS SO THAT PIPE INLET DOES NOT EXTEND THROUGH MAN- HOLE JOINT. WATER PROOF EXTERIOR OF SANITARY MANHOLES. APPROVED PATENTED COMPRESSION TYPE JOINT. DEFLECTION ANGLE AS REQUIRED. BASE PLAN 1) THE MINIMUM INSIDE DIAMETER FOR THE BASE AND RISER SECTIONS SHALL BE 42 INCHES FOR 8 INCH DIAMETER SANITARY SEWERS AND ALL STORM SEWERS. THE MINIMUM INSIDE DIAMETER FOR SANITARY SEWERS LARGER THAN 8 INCH DIAMETER IS 48 INCHES. MANHOLE SHALL MEET ASTM C-478 REQUIREMENTS. 2) FLOWLINE ELEVATION OF INCOMING PIPES SHALL BE 1 INCH HIGHER THAN THAT OF OUTGOING PIPE. 3) PIPE SIZES LARGER THAN 24 INCH DIAMETER MAY REQUIRE MANHOLE DIAMETERS OF 60 INCH, 72 INCH OR 96 INCH AS DETERMINED BY OUTSIDE DIAMETERS AND ORIENTATIONS OF CONNECTING PIPES. 4) ECCENTRIC CONES SHALL BE USED ON DIAMETERS 60 INCH AND LARGER. STEPS SHALL EXTEND DOWN VERTICAL WALL OF CONE. 5) PRIOR TO FABRICATION, SHOP DRAWINGS SHALL BE SUBMITTED TO THE DISTRICT FOR APPROVAL OF MAN- HOLES ON PIPE DIAMETERS LARGER THAN 24 INCH AND ALSO FOR THOSE STRUCTURES WITH A DROP PIPE CONNECTION. PRECAST CONCRETE MANHOLE METROPOLITAN ST. LOUIS SEWER DISTRICT Standard Details of Sewer Construction Dr. WSH/SAM Ch. J.C.K. 2009 SHEET 21 (REV)