An analysis method will now be explained which provides a safe analysis for self-supported floors such as raised floor slabs. Users are recommended the following steps be taken:
Create a separate job with a single floor group: the one in which the raised floor slab is located. The reason for doing this is that if the raised floor slab is defined jointly with the rest of the structure, as the program discretises the beam running along the top of the wall, if any horizontal loads are present, the beam will work removing bending moments from the column between which it spans. Therefore it will reduce load eccentricities from the column loads, providing unfavourable results. Additionally, the program does not design the reinforcement of this beam.
Introduce the dead and live loads as if they were the final load states of the job, without taking into account the construction process.
Introduce the wall supports.
Introduce the floor slabs.
Assign a fixity coefficient equal to 0 to the floor slabs. This way, the slabs are designed as being simply supported with all their load, which implies they have an added safety factor. In reality, it is sufficient if the top moment is a minimum, ¼ of the positive moment of the span, which is the way the program calculates the negative moment at the end of the joist.
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