Delivering the waterproofing strategy on this prestigious and famous building in London. The project consisted of creating two new sub levels either side of the arch house amenities for a luxury hotel including a spa, swimming pool and ballroom. The Admiralty Arch basement project ultimately won the Structural Engineering category of the Year in Infrastructure Awards 2019 for its complexity.

THE CHALLENGE

Xypex was the only form of waterproofing and used in all elements of this build comprising of 3 separate basement elements located above two London underground tunnels, connecting to an existing basement via the ‘South Box’ link tunnel. Each structural element needed to be as thin as possible to maximize space but a thicker foundation raft slab was required to minimize movement to the tunnel. A secant box construction method was undertaken on both sides of the arch and a 1m perimeter of the ground floor slab completed the waterproofing continuity throughout.

THE XYPEX SOLUTION

Xypex’s minimum thickness requirement of 150mm (when poured as a single piece of concrete) allowed the engineer to maximize space while our monolithic pour detailing allowed a cost saving on the 1200mm thick raft slab. A full set of project specific CAD drawings were created to allow for clear construction joint detailing including concise underside of capping beam joints, form work anchors, steel columns, tie bolt and duct sealing.

Xypex Admix C Series – Ground floor slab 1m perimeter pour, basement slab B1, basement walls B1, basement slab B2, basement walls B2, lift pits, south core, link tunnels.

Xypex Concentrate – All construction joints.

Hydroswell Bentostrip – All construction joints, kicker joints and cast in penetrations.

THE RESULTS

SMR Projects delivered 1450m3 of Xypex waterproof concrete across the various build elements as a single form of waterproofing and signed off a dry habitable environment complete with a 25 year warranty.