Specifications

NAIROBI OPERATIONAL HUB
UNOPS Building, UN Lane, Off UN Avenue Tel: [phone]
P.O Box 783,Village Market, 00621 E-mail: [e-mail]
Nairobi, Kenya Website: www.unops.org
UNOPS is ISO 9001 certified
D. The PVC coated rigid steel transition bend or conduit shall extend minimum 150
mm above grade. A concrete envelope 100 mm high above the finished floor shall
be formed around such risers to minimize corrosion at point of emergence. The top
of the envelope shall be sloped for drainage.
3.05 CONSTRUCTION OF MANHOLES AND HANDHOLES
A. Manholes and handholes shall be constructed of precast or cast-in situ concrete to
sizes shown on the Drawings. Horizontal concrete surfaces of floors shall have a
smooth steel trowel finish.
B. Frames and covers shall be watertight and covers shall fit the frames without undue
play. These shall be free from warp and blow holes that may impair their strength of
appearance.
C. Steel and iron shall be formed to shape and size with sharp lines and angle and shall
have a smooth finish.
D. Provide all necessary lugs and brackets.
E. Set pulling-in irons and other built-in items in place before pouring concrete.
F. Provide a 3 m earth rod external to each manhole and handhole. Also provide an
earth bar in each manhole and handhole affixed to the wall above the duct bank box-
outs. Connect to earth rod using 70 mm² bare copper conductor and bond earth
conductors associated with each power cable inside the manhole or handhole.
3.06 CABLE WARNING SIGNS AND TAPES INSTALLATION
A. Direct buried cables shall be installed in accordance with the requirements for
external cable installation given in Section 16120.
B. Cable warning signs shall mark all direct buried splices and shall be placed at
intervals not exceeding 30 m along the cable route.
C. Cable warning tapes shall be installed 300 mm directly above cable throughout the
entire cable route and shall cover the full width of cable trench.