Drawings for Sewer and Water - City of London

.COarse sand
Plein or reinforced concrete_
to be 15 MPA before
backf;lling - Formed
Crushed stone
Max. size 19mm
Formed or poured
1/4 0. D.
b 40.D.
(100 Min,)
CLASS A-1
CONCRETE CRADLE BEDDING
Coarse sGnd
Plain or reinforced concrete
tobe 15 MPA before
backfilling - Formed
Crushed stone
Max. size 19ram
NOTES:
1. ’W’ = O..D. + 200mm for pipe sizes up to
and including 600mm in dia. and 1-1/40.D.
for pipe sizes greater than 60On, n;
2. ’P’ is the ratio of area of steel to the
Grea of concrete at the crown for
concrete oroh. and at the invert for
, concrete cradle.
3. All b~dding materials to be mechanically
compacted in Occordence with City of London
Standurd Contract Documents
a. When reinforcing steel is required to
obtaih ~ specifio load factor, design detail
shall be submitted to the Contract
Administrtotor for epprov~l.
A. ALL DIMENSIONS.ARE IN MILLIMETERS
UNLESS OTHERWISE SHOWN
Load Factors:
~ 2.8 for plain concrete
= 3.4 for reinforced concrete
wi.th p =.0,4%
= 4.8 f.or reinforced concrete
with p = 1,0%
CiTY OF LONDON STANDARD DRAWING
.>~LASS A-1 CONCRETE CRADLE BEDDING AND CLASS A-2
CONCRETE ARCH BEDDING FOR RIGID PIPE
1996 05 15 crfY ENGINEER