Geotechnical Desk Study - Islington Council

Geotechnical Desk Study
xii) Diagonal fracture (within the track side elevation) extending from the extrados ring of the
ground floor arch window, down to the corner of the building – visible externally and internally
xiii) Wall constructed along the crest of the cutting slope with evidence of vertical
settlement/slippage of the end wall from the main building. A wide opening has formed
between the front wall elevation and gable end
xiv) It appears that the front wall is not ‘keyed’ into the end wall at gable end suggesting the wall
to be a later construction (perhaps replacing an ‘original’ doorway opening into the main
building during use as commercial premises). However, the front wall has a number of visible
diagonal fractures, again indicating settlement/slippage of cutting slope material below.
In addition to the localised defects highlighted above, it appears that a large percentage of the
visible defects have arisen from foundations movement issues such differential settlement,
foundation rotations and sliding, caused by soil creep or associate ground conditions discussed in
detailed in Section 8.
In view of the orientation and distribution of retaining walls fractures (e.g. East Side Boundary
retaining wall) in conjunction with the actual wall geometry, we can draw the conclusion that the
wall foundation slippage has produced large scale rotation of wall and extensive damage along
the entire length of the structure. The sensitivity of the retaining wall footings to the underlying
ground movement, may be a result of the wall construction details, such as inadequate sizing and
depth of footings in relation to the actual ground conditions. However, this is subject to
confirmation by record drawings or site investigations, as appropriate.
5044006/002 Geotechnical Desk Study (2).doc 17