Portcullis House – Category III Design Check and Ground Movement Assessment

Working Platform Design for Scotland’s Tallest Residential Building

Ground Projects were appointed to support the development of Scotland’s tallest residential building, an over 30 storey student accommodation tower, by delivering specialist geotechnical design services and a ground movement assessment for the permanent works and two temporary tower cranes.

The tower cranes reached heights of up to 90 metres and were founded on large reinforced concrete bases overlying CFA bored piles. The piles were installed within challenging ground conditions, comprising variable Made Ground and very soft tidal flat deposits, overlying bedrock.

A key project constraint was the close proximity of Network Rail infrastructure. The adjacent railway cutting is supported by deep masonry retaining walls extending nearly 10 metres below pavement level, requiring careful assessment of ground movements and structural impact.

Ground Projects undertook a Category III independent design check of the tower crane pile foundations using multiple analytical approaches in line with Eurocode 7 and BS 8004:2015 for single and group piles.

Following approval of the temporary works design, a finite element analysis (FEA) was completed to predict the ground movements generated from the permanent works and assess the impact on the nearby railway assets.

Our involvement helped ensure the safe delivery of critical construction infrastructure on schedule and on a constrained site with complex ground conditions and sensitive adjacent assets.