HSE word is out on Pipers Row car park collapse

When the Pipers Row car park in Wolverhampton collapsed in 1997 the HSE commissioned research into the cause. The findings of that research have now been published.

A 120-tonne section of the top floor of the 1965-built car park collapsed, starting with a punching shear failure at one column which spread to eight others.

The good news is that the failure wasn't down to the type of structure, called Lift Slab because it was built by lifting concrete floor slabs up on to pre-cast columns and wedging them in place.

The bad news, though, is that the disaster was caused by a series of little oversights at the design, construction, inspection and maintenance stages. It's bad news because human error can be infinitely repeated, but to prevent this the HSE recommends:

• Assess strength loss and the rate of deterioration when you see poor build quality or deterioration. The current practice of corrosion check surveys may miss problems
  
• Core tests should be done on concrete if it looks poor to work out its exact strength
  
• Invent inspection regimes that will catch deterioration that superficial inspections miss
  
• If reinforcement drawings are not available, get in there and establish the rebar detail
  
• Design code BS8110 oversimplifies the loadings and stresses. Actual construction tolerances, as-built strengths and the effects of deteriorations should be considered
  
• The risk of progressive collapse should be considered by looking at load redistribution
  
• Deterioration, corrosion or cutting should be checked by a structural engineer rather than considered as a cosmetic repair.