A FLOOR that collapsed underneath hundreds of bargain-hunters at a Spanish furniture store last week may not have been properly strengthened more than 20 years after it was first found to be under designed.
No one died in the accident but 185 shoppers were injured, eight seriously, when they fell 4.5m into the basement of the warehouse-style Muebles Peralta store in Dos Hermanas near Seville last Thursday.
The accident is one of the most serious building-related catastrophes on record in Spain. A 90m2 hole opened near the tills in the store, which had been inundated with shoppers after the owner had heavily advertised a sale of armchairs for £12 each.
The structure was purpose-built for the Muebles Peralta chain in 1975. The designer was a local structural engineer Otcile and the contractor Construcciones Vincente Laguna. Floor construction is reported to be typical of the period, with insitu concrete-topped hollow core concrete blocks spanning between small section concrete I-section purloins at 600mm centres. These in turn span 6m between the main steel I-beams, which sit on exposed fabricated steel columns.
After the collapse it emerged that, in 1993, Muebles Peralta won £350,000 in damages from Construcciones Vicente Laguna, following a court case fought over structural problems dating from the time of construction. Muebles Peralta subsequently retained former Otcile engineer Manuel Garcia Pizarro, who found remedial work was needed throughout the structure.
It is still unclear if the damages sum was invested in comprehensive strengthening or whether only the visible faults in the structure were made good.
Antonio Gonzales Garcia, a representative of local architectural technicians institute the Colegio de Aparajedores, said that standards in Spanish buildings of the same age were generally good, and insisted the con- struction problems in this case were almost certainly a one-off.
But he added: 'If the same engineer and contractor were responsible for more buildings, these would have to be checked before we can be sure.'
Local press sources familiar with the original court case have suggested that the floor had been designed to take a loading of only 2kN/m2. In 1975, this was considered a bare minimum for European domestic-type structures - UK building codes at the time specified a minimum of 4kN/m2 for department stores.
However, Spanish building code AE88, introduced in 1988, now demands 4kN/m2 for domestic structures and 6kN/m2 for office and commercial applications.
According to the new chairman of the Eurocode Actions on Structures committee, Professor Haig Gulvanessian, the draft Eurocode on structural loading requires 4.5kN/m2 for department stores, plus an allowance for point loading from displays.
A judicial investigation in to the collapse is under way in Dos Hermanas, home town to many of the injured. The investigations are expected to take up to a year. Seville's Consumers Association is planning legal action against the Muebles Peralta chain for failing to take due care of the public.
Andrew Mylius in Dos Hermanas, Spain.