What is natural period for first mode of 20 storey flat slab building
What is natural period for first mode of 20 storey flat slab building
(OP)
Dear all,
Can anyone suggest a common & proper first fundamental period for 20-storey building using column, flat plate and a shear wall system? I am dealing with a design of one building. It has been found that the first mode (in torsion) has a period about 5.7 sec.
Thank
Can anyone suggest a common & proper first fundamental period for 20-storey building using column, flat plate and a shear wall system? I am dealing with a design of one building. It has been found that the first mode (in torsion) has a period about 5.7 sec.
Thank






RE: What is natural period for first mode of 20 storey flat slab building
RE: What is natural period for first mode of 20 storey flat slab building
I think that period of 5.7s isn't unusual, since you have very soft torsional layout. Listen to dougantholz advices.
RE: What is natural period for first mode of 20 storey flat slab building
Thanks for all useful advices, esp. dougantholz. I have tries adding edge beams of size 800x400 to avoid serious reduction in clear height. The period is now gone to 4.17 s. Still the torsional mode is dominant. I would have question whether we need to completely eliminate this torsion susceptibility, i.e. first mode shall not be a torsional mode, if so.
Sincere