The Royal Plaza Hotel Collapse
Background on Collapse
Friday 13th August 1993 at
10:10 a.m.
 Collapsed
 The
 379
collapse took less than 10 seconds!
people were buried, killing 137 and
badly injuring 227.
Structural History

Originally constructed with three storey’s and
an underground level.

Planning permission granted in 1985 for
addition of three extra floors.

In 1990, three extra storeys were added. No
foundation or columns strengthening.
An uncommon Collapse
 No
modifications added to the building in
the previous three years.
 No
extreme conditions in the environment
or loading applied to the building.
The Investigation

The factor of safety of the columns was almost
1.
 Over designing the initial structure led to the
delay in the building collapsing.
 Creep deformation occurred in the columns as
they were carrying dead loads of 70-80% of their
strength capacity.
 ‘Progressive Failure’ – the collapse of the initial
columns, caused the remaining columns to fail.
Tests Conducted



Test of Concrete Strength – strength was
in the range of 10 – 15 MPa with 95%
reliability.
Test of Rebar – steel was found to confrom to
standards.
Soil Test – the bearing capacity of the soil was
sufficient to support even the expanded 6
storey building.
Remedial Measures Taken





Public Universities were ordered to review the
safety of a number of buildings.
218 buildings were investigated.
Registration of engineers must be more strictly
controlled.
Public buildings must carry a license which must
be renewed every five years.
Design of future public buildings must be crosschecked by a third party engineer who will also
be held responsible.
 Any
Questions?