Ronan Point Collapse Group 1: Gareth Nolan James O’Brien Jennie Quigley Laura Woodbyrne.

Ronan Point Collapse

Group 1: Gareth Nolan James O’Brien Jennie Quigley Laura Woodbyrne

Background

Housing destroyed by 2nd World War Development of prefabricated construction

techniques Therefore high-rise apartment buildings:

Large numbers of people Save land Constructed quickly Affordable

The Building

Clever Road, East London 22 storeys high Total of 110 apartments Consisted of both one and two bed Cost £500,000 to build

The Structure Construction began on July 25 1966,

completed March 11 1968 (less than 2 yrs to build)

Larsen – Nielsen method of construction Developed in Denmark in 1948 Walls, floors & stairways all pre-cast Slotted into place and connected on site Minimise amount of on-site construction

work Each floor was load bearing and supported the

floor above.

The collapse

5.45a.m May 16th 1968 Apartment 90 on the 18th floor Struck a match to light gas stove Explosion due to a gas leak resulting from

a substandard brass nut Magnitude of explosion very minor,

(<70kPa) should not have led to such a collapse

Apartment 90 on the 18th floor

Force of explosion knocked out the opposite corner walls of apartment

These walls were sole support for walls directly above.

Chain reaction All these floors collapsed onto floor 18

which was unable to take the extra weight. Floor 18 then collapsed onto floor 17,

which fell on floor 16 and so on to ground level.

Floor plan of the apartments:

Collapse sheared of the living room and kitchen portion of the apartments, leaving bedrooms intact

4 People died & 17 were injured. The reason for such low fatalities was

that almost all residents were asleep in their bedrooms.

All of the fatalities occurred in apartments 17-22, where the bedrooms also collapsed.

Cause of collapse Lack of structural redundancy No fail safe mechanisms No alternative load paths to support

upper floors should lower floors collapse

Building codes not kept up to date Poor workmanship

After the collapse

Reinforced with blast angles Continuing public concerns Demolished in May 1986, only 18

years after completion Life expectancy of 60 years.

Effect on building regulations

Initiated changes to the regulation codes Must now account for progressive collapse Also consider forces from an internal

explosion Minimum amount of ductility and

redundancy to be factored into design