Progressive Collapse

Progressive, or disproportionate, collapse is an inherent issue with RF structures. The structures rely on interlocking of the main members, which means that the accidental removal of one member can potentially mean the collapse of the entire structure. The building regulations, codes of practices or national standards in many countries stipulate that the risk of proportionate collapse must be addressed in the design. Normally, the regulations will specify what type of buildings or structures, or in what proportion of the structure, collapse would be acceptable if a single member was accidentally removed. Therefore, for relatively small RF structures, or for lower risk building groups (for example, low-rise dwellings or agricultural buildings), the design may not be subjected to any special restrictions with regard to disproportionate collapse.

For larger structures or structures of greater importance, where the consequences of collapse are more severe, design measures would need to be included to deal with the risk of progressive collapse. These may include additional tying of members that act as diaphragms and allow individual members to be held up by catinery action. Also, in seismically active areas it would be important to ensure greater structural redundancy. In the case of the Japanese RF structures, the earthquake energy is dissipated by designing timber joints without steel connectors, which allow the structure to move with the earthquake motion. An excellent example of increased structural redundancy is the Seiwa Burnaku Puppet Theatre Exhibition Hall RF structure, where a double RF structure of clockwise and anticlockwise spiralling RF beams is used for the roof. In the case of the progressive collapse of one of the RF structures, the other will take over the redistributed load of the roof. Further research needs to be carried out to explore the structural behaviour of RF structures, especially when they are subjected to dynamic loadings. Despite the fact that there is a need for further research, it is clear from the Japanese built examples that progressive collapse is a problem that can be successfully resolved.

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Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

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