In order to supply rescue personnel with training material a data base with pre-run collapse simulations was created. This building library consists of four building types that are archetypical representations of a number of commonly built structures:
1. Vitruv Building #2: a low apartment building
2. Vitruv Building #3: a high rise building with a square shaped floor plan and a center core
3. Vitruv Building #9: a high rise building with a rectangular floor plan and a center core
4. Vitruv Building #11: a historic, double wing brick building
Those four buildings have been submitted to various explosion and earthquake scenarios. Damages from detonations were defined and earthquakes with four ascending intensities from low to devastating were simulated.
This building library is expected to be extended in the future to not only serve training exercises but also allow more and more accurate predictions where hollow spaces will be formed in which victims can survive.
In the beginning the videos show a new useful BCB functionality: A mesh of the concrete rebar is generated following the definitions in the BCB´s Formula Assistant namely rebar position amount and sizes. This rebar mesh is only for diagnostics to detect obvious mistakes in the element settings and is not linked to the simulation routine.
We picked up our initial approaches (blog post from 20. Mai 2015) to visualize cavities and applied a modified version on the collapse debris mesh. We could prove that cavity can be visualized fast and directly in Blender largely with Blender´s native inbuilt modifiers. The result can be seen in the last sequence of the videos.
The 6th plenary meeting took place from from 7.-9. of November. It was an intense succession of status updates, workshops, and discussions. It is a great pleasure and honor to work with top scientists and accomplished engineers. The atmosphere was despite the intensity of the meeting schedule relaxed and joyful. It felt almost like the reunion of a big family.
LUAS´presentation was well received among technical partners and end users. We got good feedback and fresh inspirations. It makes it always a pleasure to present when the topic is interesting and when tools such as the BCB work neatly.
This video shows the simulation of the second building from the building library. Two damage scenarios were examined: a pillar removal due to explosion and an earthquake. The pillar removal did not lead to collapse. The video displays the reaction when the strong earthquake time history was applied.
The building library collects a range of typical building structures (9-10 buildings) including structural details. Prone to collapse risks are examined and the collapse shapes are exported from the simulations in a digital exchange format DXF and OBJ. The building library can be used in a real collapse case to estimate the probable location of cavities.
The removal of these two pillars did not lead to collapse.
According to an Indian source: “A single Judge investigation committee and a Special Investigation Team (SIT) were formed by Tamil Nadu government to investigate the cause of the disaster. The major reason for this disaster was due to the carelessness of the builders in Chennai. The chief engineer handling the construction accepted his mistake and was fined by the police.”
Unfortunately the reasoning for the collapse was not given in detail. In this video the building shows a remarkable stiffness towards the end of the collapse. This contradicts the accusations that the building was prone to collapse at any time by its own self weight.
Here is a video and download link for the virtual training tool prototype created using Unreal Engine 4. The building model is from a collapse simulation of the Pyne Gould Corporation building in Christchurch, New Zealand. The simulation was made by Laurea UAS as a part of INACHUS´ software validation cases .
At the current stage of the prototype, the user will try to find and evacuate all victims in the scene. The prototype will hopefully be improved further by another student, so it can be brought to a point where it could be used as a virtual training tool to reduce costs in Urban Search and Rescue training. For example adding first aid, techniques and decision making according to the USaR principles could be implemented in the tool.
The project was done by Ville Tiira as an internship and thesis, which are a part of the Bachelor’s degree in Business Information Technology in Laurea UAS.
We are happy that our Pyne Gould simulation was noticed by the creator of the Bullet Physics library himself. The video is now cross-linked on his personal Google+ profile:
The claim that the apartment building in Chennai (see post below) collapsed because of a lighting strike sounds- at first- far fetched, since such never was reported before. However, the Polytechnic Südwestfalen, Germany, made laboratory tests that showed that an enormous explosive power is mobilized, when the charge of a lighting jumps from one reinforcement iron to another (when not properly bound together). A possible lesson for engineers and builders in the industrialized countries as well.
© Polytechnic Südwestfalen, Prof. Dr.- Ing. Jan Meppelink