Knauf Seismic Design

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Types of Collapse and Damage The collapse of buildings can either be global or local. The term local implies that only a part of the load-bearing structure or a single construction component collapses. When a collapse is termed global, the whole structure is considered to have been destroyed. Cracks, plastic displacements etc. are damages which can cause the loss of a building’s usability, as well. Apart from basic “under dimensioning,” the following types of collapses may occur due to errors in either the conception or execution of buildings: The “soft story effect” (fi gures 2 and 3) occurs due to a story with little rigidity (for architectural reasons mostly the ground fl oor) that attracts stresses from rigid stories and subsequently collapses. It is the weakest part of the structure. Strictly speaking, it is a local collapse, but it can cause a global collapse and lead to the ultimate loss of the building. The “short columns effect” (fi gure 7) is caused by undesired load swaps into construction components that are not divided well enough from the load-bearing structure. The reason is the subsequent increase of rigidity through masonry and the following higher seismic load due to the shortening of the swing period. The sudden and unannounced collapse of infill masonry (fi gures 6 and 8) is extremely dangerous to people in the building. It can even lead to a complete collapse of the whole building (fi gure 5). The reason is the higher rigidity of infi ll masonry, as compared with the softer columns, that causes the swapping of loads into the masonry. The brittle material collapses in an explosion-like manner. 6 Figure 6: Collapse of infi ll masonry Figure 7: Short columns effect Figure 8: Collapsed infi ll masonry
Knauf Seismic Design Less Weight - Less Trouble Example according to Eurocode 8 (EN 1998: 1997): (figure 9) ● 7-story residential building ● Reinforced skeleton construction ● Total height: 19 m ● Ground area 18 x 12 m ● Reference value of horizontal ground acceleration: 0.4 g ● Total weight of load-bearing compo - nents: 1095 t ● Total weight of walls (masonry incl. plaster = 200 kg/m² interior / 240 kg/m² exterior)): 518 t ● Total weight of walls (interior: Knauf W112, 49 kg/m², exterior: Aquapanel, 42 kg/m²) : 109 t ● Total weight of building: Figure 9: Skeletal frame of a 7-story building Table 3: Load values for cited example Interior Walls Exterior Walls Total vertical load for earthquake calculation Masonry (200 kg/m²) (240 kg/m²) Knauf Systems W112 (49 kg/m²) Aquapanel (42 kg/m²) 17.8 MN 13.7 MN with masonry: 1614 t with Knauf systems: 1204 t (25 % less weight when Knauf Systems are used instead of masonry) By calculating the earthquake loads according to Eurocode 8 it can be determined that these loads are decreased by Total horizontal earthquake load according to EC 8 at a 0 = 0.4 g 4.0 MN 3.1 MN approx. 23 % when using Knauf W112 for interior partitions and Knauf Aquapanel for exterior walls. Ratio 100 % 77 % A more economic dimensioning of the expensive reinforced concrete structure thus becomes possible for both static and earthquake loads. Additionally, earthquake safety is improved due to the better deformation and collapse behavior of drywall constructions in the event of an earthquake. 7
Page 1 and 2: Knauf Seismic Design Edition 08/200
Page 3 and 4: Soft Buildings Advantages: Appropri
Page 5: Knauf Seismic Design Seismic Zones
Page 9 and 10: Knauf Seismic Design Applications N
Page 11 and 12: Table 6: Maximum Resistible Horizon
Page 13 and 14: Table 8: Knauf Suspenders 0.25 kN A
Page 15 and 16: Table 10: Collapse loads for metal
Page 17 and 18: Knauf Seismic Design Material Value
Page 19 and 20: Table 14: Selected international st

Knauf Seismic Design

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