Movements and partial collapse of a 130 year old brick retaining wall at Lansdowne Crescent in Worcester had led to partial closure of the road. Previous attempts to prop the wall had failed and in places the wall appeared to be moving away from the stationary buttresses. Conservation requirements added significantly to the challenge of the task of stabilisation.

Given the age and aesthetic value of the wall, the client wanted to avoid defacing its Victorian charm by fixing nails and bearing plates on the face. Phi Group overcame this by coring out the wall at each of the 420 nail positions to a depth of 250mm, fixing the nail plates and replacing the core.

Solution:
Phi Group assessed the bearing pressure of each plate position and improve areas of poor quality mortar by pressure grouting before fixing the nail plates. With the nails in place, Phi replaced the circular brick cores and by selecting a mortar to match the original lime based products, produced a repair that is invisible at a distance. Structural work, including rebuilding another section of wall and localised repointing, was completed in eight weeks.

Phi Group planted replacement trees, once the slow-worms returned to the allotments in the spring.