A Novel Approach to Bracing a Piled Retaining Wall using Temporary Piled Buttresses-Video

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Hannah Davis of Cementation Skanska presented a temporary propping solution for a retaining wall at a new commercial arena in Manchester, on a site affected by historic coal workings. Strict movement limits, deep excavation, nearby utilities, and construction-access needs made conventional berms, horizontal props, raking struts, and ground anchors unsuitable.<br /><br />The team proposed 19 temporary secant-piled buttresses, comprising 133 piles, arranged perpendicular to a 200-metre contiguous piled wall. Their locations and stiffness were iteratively coordinated with permanent works and bearing piles. Numerical modelling informed the design, while site monitoring recorded wall deflections below the 25 mm limit and generally below predictions.<br /><br />The buttresses enabled earlier berm removal and uninterrupted access for excavation and piling, saving time and cost. Davis noted that additional ground-stiffness testing and more extensive instrumentation—such as inclinometers or fibre-optic sensing—could improve future designs and validation. In discussion, she clarified that the buttresses were separated from the wall by a gap and connected only through the capping beam.

Keywords

temporary propping

retaining wall

secant-piled buttresses

Manchester arena

ground movement monitoring