Dead and Superdead Loads
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Dead and superdead loads Dead loads are typically loads which the program can calculate by itself based on geometry (length, width, thickness) and material properties specified (density). Steel framing member weights are automatically calculated by the program. Any dead load which cannot be calculated by the program need to be input as a SUPERDEAD. Examples of this could be slab finishes (marble, tile), masonry loads etc. Live load reduction is typically permitted for columns supporting multiple floors, as recommended by ASCE 7. The reduction of live load is based on probabilities. Assume that you have a 25 story building, with a column supporting a tributary area of 30'x30' on each floor. The chances that each one of these floors has a live load at the same time is unlikely and the code allows you to reduce the load based on its "Influence Area". Greater the influence area, the more reduction you are allowed to take, but no more than a 60% reduction on live loads. Minimum Lo = 0.4 L. Some restrictions apply, check Chapter 4 of ASCE 7.
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Dead and Superdead Loads
Transcript of Dead and Superdead Loads
Dead and superdead loads Dead loads are typically loads which the program can calculate by itself based on geometry (length, width, thickness) and material properties specified (density). Steel framing member weights are automatically calculated by the program.
Any dead load which cannot be calculated by the program need to be input as a SUPERDEAD. Examples of this could be slab finishes (marble, tile), masonry loads etc.
Live load reduction is typically permitted for columns supporting multiple floors, as recommended by ASCE 7. The reduction of live load is based on probabilities. Assume that you have a 25 story building, with a column supporting a tributary area of 30'x30' on each floor. The chances that each one of these floors has a live load at the same time is unlikely and the code allows you to reduce the load based on its "Influence Area". Greater the influence area, the more reduction you are allowed to take, but no more than a 60% reduction on live loads. Minimum Lo = 0.4 L. Some restrictions apply, check Chapter 4 of ASCE 7.
