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
K. An expansion joint of 55 mm per 100 meters maximum shall be provided in the duct
banks. Additionally, a construction joint shall be installed if pouring of concrete is
commenced any time after initial set of adjacent concrete. Neither expansion nor
construction joints shall be installed under a roadway.
L. For duct banks in stable soils, the soil below the duct bank shall be compacted to 90
% of maximum density to a minimum depth of 300 mm. A dewatering system shall
be used to lower the water table below the final excavation depth to eliminate
disturbance of in-situ soil densities.
2.03 STUB-UPS
A. Stubs-up for electrical equipment connections and other requirements shall consist
of either 100 mm or 150 mm diameter hot double-dipped galvanized rigid steel
conduit entirely encased in concrete.
B. Rigid steel conduits and bends for stub-ups shall comply with the requirements of
Section 16130.
C. The bends for stub-ups shall be 90 degrees with a minimum radius of 1200 mm.
D. Bends for stub-ups shall serve as transition between PVC conduits embedded below
grade and rigid steel conduit installed exposed on surface. Such bends shall be
provided with a PVC steel coupling on one end and a threaded male or female
adapter on the other end.
2.04 MANHOLES
A. Appropriate type and size of manholes shall be provided as shown on the Drawings
or required on site in compliance with the requirements of Local Standards
Organization, BS and Electricity supply authority or Telecom supplier regulations.
B. Manholes for communication and low current systems shall be constructed in
accordance with the standard practice and requirements of Telecom Supplier.
Regulations.
C. A sump pit shall be built into the base slab directly beneath the manhole opening to
collect and retain any water present in the manhole. Periodic maintenance may be
required since sump pumps will not be permanently installed.