abdulqadeer29

first define Service load cases as per UBC, then you will get what you need....

in Safe , you have to provide value of modulus of subgrade, you can't define bearing capacity. Geo technical report should mention actual modulus of subgrade , otherwise you have to do it on the basis of load and allowable settlement. ( BOWLES - Foundation Analysis and design) As you have mentioned that you are new in this field, you should concentrate on manual calculations, it would be utter madness if you simply accepted your software results without any manual checks and without any involvement of your engineering. if you are giving 48 inches raft for 5 storey building, it is too too much ( if it is commercial or residential), it means your loading ( live and dead loads) need correction. verify them from UBC OR ASCE. Calculate Punching manually first.

Parameters including Guidelines set by different authorities on the basis of RESEARCH WORK. As a Structural Design Engineer you have to follow code in every aspect and remain within the boundary lines set by codes.

what i have observed is , we generally avoid expansion joint in foundation, but i have read from few books which recommend expansion joint in foundation as well...

i have one more point, should we have to separate foundation as well, if we are providing expansion joint???

our main problem is regarding temperature and shrinkage. in case of seismic, this building behave well due to presence of main two heavy cores in resisting against seismic forces without expansion joint. i am attaching complete plans just to give you an idea of typical floor plans. now can i avoid expansion joint by increasing temperature and shrinkage reinforcement.?? 4th. to 13th.Floor Plan.pdf Basement-1 to Basement-3.pdf Lower Ground to 3rd Floor Plan.pdf

sir, issue is not about location, it is more about whether we should provide it or not.?? according to some views , it is recommended that we can increase temperature and shrinkage reinforcement and avoid expansion joint. i am still at the same point, should i go for ????

i have attached column layout plan of a 20 storey building,i am dithering about its expansion joint, whether to provide it or not. not found any code evidence yet. some books recommend expansion joint after every 150-200 ft. and some even allow up to 300 feet without any expansion joint. kindly suggest some authenticated source , on the basis of that i can decide. PLAN.pdf

In etabs we use EQX , EQY for respective directions. so this earthquake force should have carry both its vertical and horizontal component with itself. so there is no need to define these modified equations when we are assisted by software. but during manual calculations we have to incorporate these modified equations. Is my understanding correct? kindly correct and explain me if i am wrong ???

how much it matters to consider all four possible cases of earthquake, when we have building without any irregularity? because it create a bit problem when you have all four cases and it become quite hectic job to bring building in a stabilizing position for all those cases??? i am solving a structure having 20 stories , and seems to be quite manageable against seismic as two main cores is located at center. but when i go for all four cases, it require extra stiffness at one side of the building in two cases. c2.bmp c.bmp untitled.bmp

Etab is for frame analysis, for basement walls you have to follow procedure of retaining walls , in most of the cases when your wall is attached with slabs at each floor , behavior of wall also vary as like beam with pin support at various points.....

do you have this book of Wilson in soft form or you can provide me any link ?

modeling iz a tool which provide us assistance but not approach to deal with such things...

Real failure iz NOT TO TRY, THOSE HAVING FEAR OF FAILURE IN THEIR MINDS NEVER ACHIEVE SOMTHING SPECTACULAR....

yup done with this project, calculate OTM due to seismic and wind forces, and made checks against bearing pressure.... check OTM , by considering tank empty,

The minimum amount and spacing of reinforcement to be used in structural floors, roof slabs, and walls for control of temperature and shrinkage cracking is given in ACI 318 or in ACI 350R. The minimum-reinforcement percentage, which is between 0.18 and 0.20%, does not normally control cracks to within generally acceptable design limits. To control cracks to a more acceptable level, the percentage requirement needs to exceed about 0.60% (REFRENCE ACI COMMITE REPORT 224R-01) So according to above statement , should we follow 0.60%, to be on more safe side??

Design of concrete structures BY NILSON.

got ur point... i have removed those errors which i were getting earlier...reduce mesh size as well..but still getting same results problem in case of beams../

Rana Waseem @ one more point , i have checked my load combo's , but still getting same problem, etab is displaying end and midspan moments correctly as i manually checked as well , but reinforcement issue is still there which i mentioned earlier....

got ur point ... etab iz not mentioning those areas where load transfer error occurs, ....so how to check those areas where this load transfer error occur....???

i am getting more reinforcement in bottom even though i am getting more moment values at support in few particular areas ..i am not sure why etab is showing more reinforcemet at bottom in these particular grids? any one having any idea? untitled.bmp

got ur point.....

when there is an expansion joint provided in building, do we have to model both parts of building separately??? or we have to make a single model for both parts , ?? and second do we have to terminate our beams when there is a expansion joint, if we are making a single model for both parts of building....???

he is placing his beam at the end of the column, not at the node....as in etab we should move node to node...no doubt in actual a beam can rest at the edge of the column as a support...but in etab we should avoid this otherwise etab will not consider that column as a support... untitled.bmp

i have more concern over your framing plan than meshing....