PERIMETER COLUMN failure is emerging as the most likely reason for the collapse of a snow covered Moscow market building which killed 66 people last week.
Moscow based engineers told NCE it was likely that use of a mezzanine floor section to house market stalls overloaded the perimeter steel columns.
This is thought to have triggered column failure which then brought down the roof.
The 30 year old market is an 80m diameter circular structure with a concrete panelled roof, supported by steel perimeter columns (see diagram).
It is the third structure to fail while under snow loading in the past two months. An exhibition hall in Poland (NCE 2 February) and an ice rink in Germany have both collapsed this year.
Photographs of the collapse indicate that the outer wall on one side of the structure was pushed outwards. The wall and roof on the other side of the structure appeared largely intact.
Local media reports claimed that a mezzanine floor section around the outer edge of the building was supported by roof cables and the perimeter steel columns. It is not thought that the structure was designed to take extra resulting loads.
'If the columns were designed just to take the roof loading then the additional load from the mezzanine floor could have caused them to fail, ' said Arup Moscow associate Patrick Keating.
Market director Mark Mishiyev is reported to have been arrested on suspicion of violating maintenance regulations and endangering public health.
Local engineers said that it was unlikely snow loads triggered the failure.
'Buildings here are designed to take 1.4m of snow and there was only around 400mm on the market's roof, ' said Mott Macdonald's Russia director Howard Roberts.