ZOHAIB SATTAR NAGRA

there is a command of load applied in ritz vector window......what loads should we apply? and why? ( I am doing non linear time history analysis on building) @Rana @UmarMakhzumi @waqar saleem

plz expalin.

this is my observation , I usually found first mode (eign vector) time period to be greater than (1.4 x ELP Time period) for low rise buildings.SO thats what I was saying in previous discussion that code make conservative design by taking larger time period hence large base shear....mean while when we consider dynamic time period as in case of RS analysis we get less base shear so we get ecnomical design. @Rana @SALMAN CH. I noted that (in case of ubc 97 in etab we always get 1.4 x method A time period in low rise.)

@SALMAN CH what I have explained in paragraph 1 is that when you got less time period then you will got high base shear basically time period is inversely propportional to base shear.and ubc bound us to not take time period greater than 1.4 Ta thus leading us to conservative design .

SALAM @SALMAN CH SB. I noticed that usually dynamic time period is always bigger than (1.4Ta or 1.3TA) so thats why Etab always take (1.4Ta or 1.3TA) and we get more base shear through eqivalent static method for normal regular buildings than dynamic analysis. "what I understand is that in equivalent static method , code allow us to make ecnomical design of building by not taking method A time period and on the same side it is making conservative design by limiting method b(dynamic T) time period to 1.4 times of method A. plz correct me If I am wrong." Actually I was confused with csi manual lines shown in image I attached below. why it is saying that if "Tmode>1.4Ta then T=TA". Isn't it the contradiction to what Etab actually doing.? My deep Thanks and regards.

I have noted that when we select "program calc" option in etab then program just multiply time period of method A by 1.4 (zone 1,2,3) and 1.3 (zone 4)....any one plz explain why? @Rana

Thank you salman sb you have cleared alot of things and what I understand uptill now is (that there will come an extra reinforcement to balance the forces due to temperature in addition to seismic and gravity reinforcement) but I still have a question (what will happen to vertical shear walls directly facing sunlight?) what will happen if we apply temperature loading on these walls?axial stresses develop in wall?reinforcement?

@SALMAN CH my building is 227 ft x 170 ft with 60 ft x 60 ft opening in centre.as per ACI report 224.3 if diifference of annual mean temperature and maximum low or high temp (which ever is high ) is less than 20 C then we will give expension joint after 90m.but if it is greater than 60m then we will provide it after 60m. plz check image attached. plz explain third point I have a model file in office in which they have applied 27 degree only on roof .Why they have not applied it on buildiing exterior sides expose to climate like expterior columns and exterior beams and exterior walls on each story.? how to overcome the (axial load on beams) problem which you have explained in third point.? do we have to play with stiffness modifires? procedure?

For islamabad how much temperature (degree celcius) should I apply to my external members because in islamabad temperature varies from five degre in winter and upto 46 degree in summer.........also what if internal temperature (in rooms) is also not controlled then in this case we have to take temp affect on internal members also???

Is it necessary to apply temperature loads to all frame members ? plz shed some light. I want to skip "expension joint" in the building so I need guidence. what will be the steps and limits during temperature analysis to avoid expension joint?

Salam I am analyzing six story building and the time period of my building is 1.2 sec but my drift is under control.I have checked my all nodes and they are attached.I want to know either it is ok to go with this too high time period.I have attached my model and it is in 2016 version. 1 MODAL.EDB

SALAM to all members, I am doing my master research in PBD for tall building ....i have applied response spectrum analysis on my building....My supervisor asked me to calculate momment in my shear wall for the first governing modes of my building so that I can assign fiber hinges at where momment is critical.........(as far as my knowledge I can calculate displacement or velocity for each mode and then combine them by CQC or SRSS manually as given in alan william and many other books).My question is that how can we calculate momment for suppose first two modes (both manually and procedure to calculate it by ETABS) through out the wall.........I shall be very thankfull to all senior members who would help me in this regard as early as possible.

CAN ANY ONE PLZ SPECIFY THAT FROM THESE 6 LOAD COMBINATIONS OF ASCE FOR WIND,.... WHICH COMBINATIONS ARE USED FOR DRIFT AND SERVICIBILITY CHECK?AND WHICH WILL BE USED FOR DESIGN?