Observation
Though there was raining during the time of accident, no thunderbolt, earthquake or strong wind was reported.
Most of the roof structures including the truss collapsed. There was a huge bang prompting one of the survivors we met at the hospital under treatment to run for safe place. He felt as if the entire building was being fallen. He got very short time to run and nearly escaped.
There were two major impacts at the ground floor from the fallen debris causing punching of the marbled floor and some part of concrete underneath.
Most of the sliding plates fell whereas two sliding plates were pushed and left adjacent to the supports. The block walls provided along the sliding support line were interestingly thrown away. Fixed supports were intact and failure at these supports was brittle failure of sockets connected to the balls provided at the supports. Most of the sockets at fixed supports were failed. Base plates to the supports, where fixed supports were provided, were intact except two, which were slightly bended upwards. Three 16 mm reinforcement bars were welded to the base plates in these two places to anchor the plates to the beams and columns.
From the marks found in the base plates provided at fixed supports of short walls it seems that pipes were not fully welded to the base plates and most of the weld may have damaged before accident took place. It is speculated based on the site observation that among 5 supports on each short wall, one at the middle on each short wall was not provided a base plate.
Welding had been done at some places around the socket and ball connections. |
