lure of a random masonry retaining wall surveyed to assess causes of failure.  Self-seed Yew trees had established on hill slope above the wall and the roots had penetrated rubble fill behind the wall. Uncontrolled surface water run-off was entering the wall which had been pointed with cement mortar leading to build-up of water behind the wall and its ultimate failure due to excessive lateral earth and water pressure.

Survey identified wider risk of overhanging unstable rock mass over works area. So undertook a wider rock mass stability survey by visual survey and engineering geological mapping techniques on sub-vertical red sandstone face in river gorge setting.  Identified remedial actions and liaised with client agent and contractors to procure retaining wall repair and improved surface water drainage and to undertake preparatory temporary works to make the overhanging rock slope safe.

Failed random masonry retaining wall and self-seeded Yew trees on overlying over-steepened soil slope