Sohaib Iqbal

dfetermine the soil pressure on the raft at wall side. consider it in calculations along with the retained soil pressure on the wall and check stability of wall against overturning and sliding. 

apologies for late reply.

i hope u all are doing well. basically i modelled a symmetric G+3 structure and performed  linear dynamic analysis. after that i m trying to model with base isolators and then again will perform response spectrum analysis after considering 30 % damping. basically i have to observe reduction in base shear and change in time period bcz of rubber isolators.

respected engineers.

i m working on base isolated structures. can anyone provide me the literature and examples for this?

Respected members!

how outcomes differ when we do auto and manual mesh?

which is most accurate and preferable?

if i assign a column of 5 ft wide it will take as solid mass. how to consider it hollow (as in case of inside stairs) in etabs?

can we model it on etabs like column?

dear waqas. can we assign strips L/4 at column?

Respected engineers.

can anyone tell me that what is difference between 1st and 2nd order analysis?

specially related to steel structures also.

because it is a easier way to get maximum deflections, moments and shear on the beam having pick up column.

can we consider loads on pick up column given by etabs then apply it as point load to design beam which is supporting pick up col?

i did. etabs designing it as a column but not designing the lower beam for this pick up column load.

on different steel percentages ultimate design section takes 30 to 80 % more load as compared to ASD design sections.

yes this is true. u can verify it by solving beam using these two methods. ASD method give large sections as compared to ultimate. but it is good in achieving servicibility criteria.i will try to give u an example solving by these two methods and thier comparison.

Respected engineers!

can anyone elaborate the procedure to assign pick up column in etabs

sir Rana!

will u please elaborate the procedure of checking torrosional irregularity and procedure to deal it. as u mentioned in ur post.

Thanks

cover requirements are necessary. in case of paints it needs proper mentainance on the basis of define mentainance model otherwise weather impacts like carbonation (due to increasing content of CO2 in air) , chloride attack can cause corrosion of steel. Concrete Cover is the first defence line to prevent corrosion.

in country like Pakistan after several years we will look forward in repairing and mentainance instead of new construction. bcz some structures like bridges are our national assests. we have to work that how to upgrade then in different respects like shear , flexure, torsion. we are also facing earthquakes and after shocks. u can work on it that how to convert ordinary building into earthquake resistance by keeping in view our economy.

u can also do project on effect on the strength of structural members by the carbonation increasing content or how to monitor, mitigate existing structures like bridges etc. also give mentainance model for them.

but it isnt showing when new courses will be started?

can anyone provide me the literature for designing and analyse of pile foundations?

how we can determine in etabs either wall is in compression or tension?

waseem bhai what is the procedure to model this type of foundation in SAFE ie strap beams over raft?

my senior did the similar method in a combine footing ie provided strap beam over combine footing to reduce amount of top steel in combine footing. but i didnt get a way to model and analyze it on safe.

Umer bhai which software is recommended by you to design piles?

thanks Ahmed. but we want slab without beams ie flat slab . so we are getting very thick slabs. . so load is concentrating at edges and failing raft on soil pressure at edges also at the centre ( below lift wall). we cannot extend raft because of adjacent plots and road.

Thanks Umer bhai. we want flat slab so we are going for post tensioning in order to reduce thickness of slab. can we use ribbed slab or waffle? some one told me to to design normal slab like a hollow slab if thickness is act 14 inch or 16 inch. can we do this?