09-26-2010, 07:17 AM
(09-26-2010, 06:40 AM)paladin Wrote: Hi skyscraper,
From your words, I gues your building is a tall building containing : basement, podium & tower
I guess you separate your building into 3 model : basement, podium & tower ?
If what I guess correct, why you did not model all your building in a file of etabs ?
Doing separate analysis, do not represent real condition of the building.
I'd like to discuss tall building analysis & design ( including : calculation of R, correction of base shear, correaction of CM ... & such calculations in tall building ) with you ... if you agree.
Thanks
Paladin
Thanks Paladin
I am involved in couples of high rise buildings design ranged from 30 to 60 storey buildings. These buildings are designed with ACI and EC8 for EQ design. There are number things encountering during the design as
1) Normally we use a another software for horizontal elements design such as RAPT and Ram Concept which are not countered the lateral loads for these elements.
2) Since the horizontal elements designed as above, in Etabs model we need to define slab as membrane and release the columns to slab connection leading cores take all lateral loads. This causes annoy due to the excessive building deflection.
3) Another approach is to define the slab as shell and do not release column connection its but for beams connected to the core. We need to do another check for slab design b double the moment diagram from Etabs to add extra bars as required.
4) However, we still got the excessive shear problem on slab , especially at the open or slab slot due to lateral loads. Take an an simple example, if we apply 50kN for 100m structures, the shear transfer at the ground floor podium will be around 100,000kN at 5m height. We do need consider somehow to transfer this shear.
may you help