Royal Plaza Hotel
Korat, Thailand
Background
 Friday 13th August 1993
 collapse <10 seconds
 burying 379, killing 137, badly
injuring 227
 Technical investigation
Historical Records
 Originally 3 storey high plus 1
underground
 3 more storeys were added, no
record of foundation/column
strenghtening
Unique collapse
 Occurred 3yrs after last modification
 No unexpected forces of nature eg.
earthquake, storms
Reasons for failure
 marginal F.O.S after 3 more storeys were
added to the building
 Columns carried dead load of 70-80% of
strength capacity~microcracks causing
creep deformation
 “Progressive failure“- failure of 1 column
increased load on the other columns,
causing failure
Technical Investigation
 Test of Concrete Strength- no deficiency,
compressive strength 10-15MPa 95 %
reliability
 Test of Rebars- Reinforcing steel bars
conformed to standard
 Soil Test- bearing capacity sufficient for
foundation even after the modification
Lessons
 entrepreneurs want to cash in with
minimum investment efforts
 able and honest professional
engineers, who care more for the
standard of the works than to obey
the architects and the clients.
Short & Long Term Measures
 Safety Review of 218 buildings
 Registration of professional engineers more strictly
controlled.
 Indemnity insurance system.
 Design of public buildings must be cross-checked and
jointly responsible by third-party engineer.
 Usage of public buildings requires a license ~ renewed
every 5 or 10 years.