On 12 October 2013, the 24-storey high ‘Space’ building collapsed in Medellín, Colombia. The building had a reinforced concrete structure founded on large-diameter piles with enlarged bases. During and after construction the building exhibited structural problems and excessive settlements of some piles. Because of the evidence of structural damage, the building was evacuated on 11 October 2013, 1 day before the collapse. Isolated large-diameter piles excavated in a firm, high-plasticity saprolitic residual clay, supported building columns. Building collapse was triggered by a significant increase of the vertical load transmitted by some columns, which, in turn, is explained by widely different settlements experienced by neighbouring piles and the resulting loading transfer mechanisms. The first part of the paper presents the results of the field exploration and laboratory tests, as well as the structural and architectural layout, including the construction process and other forensic aspects that could influence the collapse of the structure. Afterwards, the joint structure–foundation–soil numerical model developed and its predictions are described. Matching the records of pile settlements, measured during construction and afterwards until building collapse, with model predictions allowed the validation of the model. The causes that triggered the collapse were identified and some other lessons were learned.

Peer Reviewed