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)