Objectives
The chief objectives of the site visit to the accident site were to
- Take first hand information from the concern officials, witnesses and injured pertaining to the collapse of the roof structure causing such a large casualties.
- Document the post-collapse scenario especially concerning remaining structures and fallen structures.
- Gather other information necessary for further scrutiny.
- Identity likely causes of structural failure of the roof structure.
Salient Features of the Accident Site
The accident site is a type of rectangular yard of size approximately 20 m by 33 m. The main hospital building at the site of accident consists of building blocks at three sides and another side is only a plane frame tied orthogonally to a braced frame at the ends. The six-story building was further raised a story consisting walls at four sides architecturally to receive light through windows in these walls.
 
Collasped roof truss Fixed support on long wall
The accident site at the ground floor was used for resting place to caretakers and visitors, housed inquiry and ticket counter. This is a place supposed to accommodate a large number of people most of the time.
This placed was covered with a space truss  roof with ball and socket joints. This roof was situated at a height of 24 m from the ground floor arranged in pagoda style. This roof structure was completed in 2000. The Consultant was Parikh and Associates, Mumbai and the Contractor was SpaceTech Engineers, Mumbai. The roof structures consisted of layers of corrugated sheets, concrete reinforced with chicken wire mesh, tarfelt layer, back mortar and slate (Fig. 3). Such a heavy roof was further raised at the middle longitudinally as told by Er. Gupta to provide another roof structure and light receiving system through sidewalls.
The roof truss was supported on 11 fixed supports and 11 sliding supports transversely along the long walls and 5 supports on each short wall. Fixed supports were welded to the base plates with stiffeners. Base plates were anchored to the RC beams. All fixed supports on long wall were tied with channel section at top longitudinally. All supports on the long walls were rested at the RC columns tied with beams.
Fixed and sliding supports on short wall were alternately arranged whereas the middle supports were simply rested on RC beam without base plate.
No permanent access to the roof structure was provided. No signs of distress were noticed or reported earlier and no maintenance was carried before the accident after completion of the roof structure in 2000. |
