Construction—EMEA—Great Britain—Foundations
High Capacity DYWIDAG Bar Anchors
for Liverpool FC’s New Main Stand
Liverpool Football Club are in the middle of expanding their main stand
on Anfield Road to increase the seat capacity to 54,000, with work
continuing all through the football season.
The new main stand features considerably
increased depth and height and will be
sheltered by a large cantilevered roof.
The huge overhang of the roof is supported
by backstays that had to be anchored
down in the ground by 12 No. high capacity
DYWIDAG Bar Anchors.
The ground anchors consist of 75mm Ø
DYWIDAG Prestressing Steel Threadbars that
were pregrouted at the DSI factory in Southam
to ensure compliance with BS8081:2015 for
permanent anchors. With an ultimate strength
of 4,500kN, the tendons are the highest
capacity threadbars manufactured.
The boreholes for the 14m long DYWIDAG
Bar Anchors were drilled into the sandstone
bedrock using a down the hole hammer (DTH)
98
with air mist flush. This new flush mechanism
features flushing jets within the stabilizer
collar of the hammer that are arranged with
different orientations to create a vortex effect.
As a result, dust is fully suppressed, and
drilling performance is increased by 10-15%.
Prior to the installation of the production
anchors, three trial anchors were installed that
were equipped with bond isolators consisting
of foam collars. The foam collars were placed
at the interface between the active and passive
wedge zones to ensure the bond developed
in the grout body of the passive zone cannot
strut against the upper grout body within the
active zone, to develop a disproportionally
high load, which could be mistaken as the
bond performance within the fixed length.
Following the successful load testing of all
trial anchors, the DYWIDAG Anchors were
approved for installation.
Due to the weight of the anchor segments,
40kg/m, each section had to be lifted using
a DYWIDAG captive bar lifting shackle, and
placed within the borehole. A tremie pipe was
attached to the lead section, to ensure that the
anchors were grouted from the base up, once
fully installed. The installation method involves
installing the first section with a coupler fork
to hold it in position, then lifting the second
section into position, rotating it fully to ensure
correct engagement of the coupler, followed
by a short lift to take the load and remove the
coupler fork. This process is repeated for each
additional section.