Integritank® HF protects
Beckton Pumping Station
Shaft, helping redirect
stormwater and sewage.
CLIENT: THAMES WATER
MAIN CONTRACTOR: MVB JV
AUTHORISED CONTRACTOR: STIRLING LLOYD
CONSTRUCTION LTD
Project overview
The Thames Water Lee Tunnel is a key part of the
Thames Tideway project and is the first stage of
improvements to London’s sewer system which will
remove combined discharges of storm water and
sewage to the River Thames and lower River Lee.
The project requires a number of large tunnels to
carry the existing wastewater to Europe’s largest
water treatment works in Beckton, East London. A
major structure in the project is the Beckton Pumping
Station Shaft, measuring 82m deep and 42m wide and
at its base, subjected to over eight bar of hydrostatic
pressure.
TUNNEL WATERPROOFING
CASE STUDY
Lee Tunnel,
London, UK
Project overview
Product selection
Summary
Beckton Pumping Station Shaft
Product Selection
Main Contractor MVB, a joint venture
of Morgan Sindall, Vinci Grand
Projects and Bachy Soletanche,
selected Stirling Lloyd’s Integritank
HF spray applied membrane to
waterproof the concave base and
lower walls of the shaft. Integritank HF
was chosen as it provides a number
of unique benefits to waterproofing
structures of this type. Designed
specifically for installation in confined
spaces such as tunnels and shafts,
the HF membrane can be tested
electrically in-situ to confirm its
watertightness, and it provides
a balance of high performance
characteristics including resistance
to mechanical damage and abrasion,
excellent crack-bridging, and rapid
application and cure. The system can
also be applied on damp concrete
free of surface water.
SPRAY APPLICATION
APPLICATION CARRIED OUT IN SEGMENTAL PATTERN
Application
The Beckton Pumping Station Shaft
is the largest shaft on the project –
enabling the pumping of effluent from
the Lee tunnel itself. The shaft was
constructed following the sinking of
an outer diaphragm wall. Dewatering
was established and the shaft
excavated. A concave concrete base
was then formed by hit-and-miss
cast in-situ concrete segments to
minimise the possibility of shrinkage
cracks. Following the application
of the Integritank HF waterproofing
membrane a protective screed was
laid, onto which an 11,000 tonne
concrete base slab was cast in place.
An inner structural wall was then
cast by continuous slip-forming and
the annulus between this and the
diaphragm wall in-filled. To house the
manifold that carries the liquids into
the shaft a Suction Culvert was
constructed on the base slab; this
culvert was also waterproofed with
Integritank HF. Inside the shaft a
dividing wall, to the full height of the
shaft, was cast and the pumping
equipment installed.
To ensure that any movement at
the joints between the 150mm
thick segments forming the
base slab could be controlled.
Authorised Contractor Stirling Lloyd
Construction applied a stripe coat
of Integritank HF along each of the
Joints, reinforced with fabric scrim,
prior to main membrane installation.
The reinforced stripe coat provides
additional tensile strength to the
membrane across the joint.
Stirling Lloyd UK & Worldwide
Stirling Lloyd Polchem Ltd.
call +44 (0) 1565 633111
email [email protected]
or visit stirlinglloyd.com
Stirling Lloyd North America
Stirling Lloyd Products Inc.
call +1 860-666-5008
email [email protected]
or visit stirlinglloyd.com/north-america
Ref. PIA_Inte023(2).pdf Available form stirlinglloyd.com
Copyright © 2016 | Stirling Lloyd Polychem Ltd.
Beckton Pumping Station Shaft
Application continued
The main membrane installation
was also carried out in a segmental
pattern to fit in with MVB’s schedule
of placement of the 150mm
protective screed. The screed was
utilised to protect the membrane
from a “scaffold” of steel tubes that
stand on the waterproofed concrete
slab to support the reinforcement
mats for the main structural
concrete slab.
The rendered walls were then also
waterproofed up to a height of
1.8m. Prior to handing over each
waterproofed segment area to
MVB, Stirling Lloyd Construction
completed their installation by
non-destructively testing the
applied membrane with a “holiday
tester”, to confirm that the
membrane was fully-waterproof.
This capability for confined space
tunnel waterproofing is unique to
Integritank HF.
Summary
The successful completion
of the Beckton Pumping
Station Shaft, utilising the
Integritank HF system
will help ensure effective
containment of storm
water and sewage from the
River Thames and lower
River Lee. Pumping the
wastewater to Europe’s
BASE CONSTRUCTION
largest water treatment
works in Beckton, East
London. This was a key
part in the Thames Tideway
project and was first
stage of improvements to
London’s sewer system.
HF STRIPE COAT AT JOINTS
SCALE OF BECKTON PUMPING STATION SHAFT
Stirling Lloyd UK & Worldwide
Stirling Lloyd Polchem Ltd.
call +44 (0) 1565 633111
email [email protected]
or visit stirlinglloyd.com
Stirling Lloyd North America
Stirling Lloyd Products Inc.
call +1 860-666-5008
email [email protected]
or visit stirlinglloyd.com/north-america
Ref. PIA_Inte023(2).pdf Available form stirlinglloyd.com
Copyright © 2016 | Stirling Lloyd Polychem Ltd.