On 28th of June 2014 around 4:40 PM IST one of two under construction buildings collapsed at a suburb of Chennai, in the Indian state of Tamil Nadu. The collapse happened during heavy rain and a thunderstorm with lightning. The building site was still busy. Workers and casual uninvolved searched shelter from the rain and frequent lightning. This is the reason the accident claimed many victims, altogether 61 casualties. Many of the survivors delivered eye witness reports. According to those reports the building collapsed directly after a lightning stroke. This might be the first documented case where a lighting caused the complete collapse of a building.
The debris pattern is most unusual, since the building was split into two halves and each half shifted to the respective side. The simulation, made by Virtual Validation Corporation Kostack & Walter, reproduces this extraordinary dynamics very well. The software was developed at Laurea University of Applied Sciences.
Now, that we are able to successfully simulate the collapse of big building structures, the software Blender gives its splendid support to exploit the simulation results for interactive walk throughs. Blender´s powerful features facilitate educational tools for rescue workers and paramedics. A training program could teach them in localizing victims within the debris, estimating their physical condition and applying first aid measures.
We have reached an impressive milestone. Our BCB add-on has evolved into a serious simulation tool: One of the software validation cases in our Inachus research has been the collapsed Pyne Gould Corporation building in Christchurch. The building was destroyed in a devastating earthquake, on 22 February 2011. The Blender add-on was able to simulate the debris pattern fairly accurately as it can be seen from the video and the still images at the end of it.
Only the simulation of concrete structures is possible at the moment. Much remains to be done, such as the simulation of deformable building elements like steel structures. The bases is laid with the introduction of spring constraints. But the working of springs in Blender needs yet thorough investigation.
This video is a first test to see if our simulation results can be used in an interactive walk through environment. The collapsed blender model is exported into the unreal game engine. Here a character can walk around, climb the debris or search inside for cavity spaces. This technology would be perfectly suitable for the education of rescue personnel. It is for example possible to apply physical behavior to debris fragments so that trainees can move pieces and experience the subsequent collapse.
The latest Bullet Constraints Builder version v.1.8 allows plastic deformation of building parts. We have added generic springs as a new constraint type.
First we thought we would attend the Blender conference only as audience, but then got invited at short notice to present our research on our simulation tool to the community . The conference was streamed live over the internet, twitter messages were cast on the theater walls in minute cycles. We admit this was all quite exciting for us. The feedback and the interest after the talk was very encouraging. Now our talk is stored on youtube.