Marple Lock, Stockport, Greater Manchester – UK

Project Overview

Constructed in 1804, the ashlar and dressed stone walls of Marple Lock 7 along the Peak Forest Canal were bulging and required remediation. The lock wall stood 6m high with remeditation required over a 9m stretch. At only 2.2m wide the lock presented a narrow working area. The solution would need to ensure the future stability of the wall whilst meeting several other criteria. Being Grade II listed, the finish of the wall needed to remain consistent and unchanged following the remediation. Due to the movement of boats up and down the lock, no structural components could sit proud or be visible on the wall.

Solution

Core holes were drilled by hand declined at 20° below horizontal; starting with a larger diameter core hole, followed by a smaller diameter core hole, into which the load plate would be recessed. Positions for Percussion Driven Earth Anchors (PDEA^®) were adjusted and staggered so that all core holes were drilled through the centre of the stone rather than across joints. A total of 36 Platipus permenant aluminium bronze BAT anchors were driven to a depth of 5m, using a Brokk 170 to overcome spacial constraints. Once loadlocked to a working load of 14kN / 23kN, the stone cores were replaced to conceal the load plate, providing a flush finish with minimal appearance of remedial works. This cost effective solution to secure the wall against further instability, was completed by Platipus Approved Installer, Holemasters Demtech, on behalf of Canals and Rivers Trust.