Case Study: 001
Secondary Containment to Steel Fuel Tanks
The Task
Our client constructed five steel tanks, each 30m diameter by 9m
high. The design required a secondary leak detection barrier and
collection system surrounding each tank including a 25mm thickness
void between the barrier and the steel tank wall.
The Solution
F.L.I. Environmental proposed the use of a 1.5mm thickness HDPE
liner in composite with a cuspated polyethylene drainage material.
The drainage material gave a void thickness beneath the HDPE of
25mm and was designed to support the short term loading of a 3
metre depth of poured concrete. The drainage material was attached
to the tank face using a synthetic bitumen tape and was fed into a
circumferencial gutter at the tank base which in turn fed a sump
beneath the tank floor.
The HDPE liner was hung over the drainage material in 4.5 metre
wide panels form the bolts around the top circumference of the
tank wall. The individual panels of liner were fusion welded
together using a heated wedge welder and individual seams were
non-destructively tested by inflating the central air channel
within the formed weld. To secure the HDPE liner at the top of the
tank wall, a drilled stainless steel batten with a neoprene seal
was placed over the protruding bolts and clamped down over the
liner to produce a seal. At the tank base the HDPE liner fed into
the collection gutter and was secured using a resin sealant. |
HDPE Geomembrane Overlying Vertical Drainage Geocomposite
HDPE Geomembrane Overlying Vertical Drainage Geocomposite |
Following the installation of the liner, steel reinforcement was
constructed around the tanks and a concrete wall was poured full
height in three 3m lifts. Earth fill was subsequently placed around
the entire structure.
Customer
RAF Fairford, Gloucestershire, England.
Management Contractor
Motherwell Bridge European Projects
Consultants
Parkman
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