6.11 Define Load Pattern for Load Cases and Mass Source for Seismic Weight │ Akshay Thakur
HTML-код
- Опубликовано: 7 окт 2024
- Lecture: 6.11 Define Load Pattern for Load Cases and Mass Source for Seismic Weight
Download Attachment to the Lecture:
[IS 1893 (Part-1): 2016] drive.google.c...
[Load Calculations and Considerations as per IS 875 and 1893 Part-1 2016] drive.google.c...
[Excel File: Design of RCC Building as per Indian Standard by ETABS] drive.google.c...
[Free] Course: Complete Design of G+3 Storey RCC Building as per IS Codes by ETABS
Course Instructor: Akshay Thakur
Watch Complete Course for Free on RUclips: • [Free Course] Complete...
Download Course Brochure: drive.google.c...
Course Description: In this course, you will learn how to plan structure with respect to architectural planning and as per codal provisions of Indian Standard codes then you will learn how to use IS Codes to calculate the loads on the structure and modelling and analysis of building structure in computer software ETABS, and most importantly you will go through the design procedure of each type of structural element manually as well as with the help of MS Excel Sheets and at last how to detail your structural sections and preparation of drawings for Construction-Site Execution purpose.
Download All Attachment Files [Resources] of Course: drive.google.c...
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
I hope you'll have a great time with my course and will learn a lot.
I'd be happy if you would give me some feedback about the course in the comment box.
Good reviews help others to find this course and enough positive energy will push me to create another course in future!
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Healthy Discussions and Queries are always Welcome inside Comment Section
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
You can also follow me on:
Blog: explorecivilsi...
Telegram: t.me/akshaythakur_civilengineer
RUclips: bit.ly/youtube-akshaythakur
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Keep in Touch with me on this RUclips Channel for, New Videos/Courses in Civil-Structural Engineering
Happy Learning,
Akshay Thakur
_If you complete the course, then I'd be happy If you give me the feedback of this course by just filling this google form_ _forms.gle/Q7gUW4untqbBszfs8_
@Kaustubh Saundane kindly update the version at least to 18.0 or latest...
btw, it won't matter alot just consider parameters like imoortance factor, etc. as per IS 2016 revision, there is just slight change in soil types cuve values for Sa/g in latest for some specific limit of time period...
many many thanx thakur sir.this is what most of the student want and where they stuck during their work .u r great .one day ur channel will be at top among the etab student
Thanks You, Sujan ...
What is the use of earthquake eccentricity why we use
Clause 7.8.2 of IS 1893(1) - 2016 states that to consider 0.05 design eccentricity to be used at floor hence it is defined and also diaphragm need to defone for this.... cause its needs to consider in each floor for analysis checks like... storey drift, actual torsion, accidential torsion and torsional irregularity, etc.
Sorry for, Edited Video as Blur at 5:46
at 5:46 I have inputed the Wind Load for +Y direction in Fy Column for WLY Load Pattern
Sir Which values have to take in Fy negative or positive..??
In excel sheet we have positive and and negative values
@@rameshgorle1760 for Wind Load-X values should put in X... for Wind Load-Y values should put in Y...
@@rameshgorle1760 you can create wind pattern in negative direction as well by for X & Y directions otherwise you can consider proper sign while used in load combination...
Dear, should we go for ESM or Dynamic analysis like response spectrum and p-delta for G+6 building? Which analysis when to use? I have assumed ESM for low rise and dynamic for high rise like above G+7. So tell me which one to use when? Thank you in advance.
read clause 7 of IS 1893 for better understanding when to use dynamic analysis ... for p-delta considerations and checks and privisions go through IS 16700 ...
watch video lectures 4.4, 5.1 in the course for more ...
as you mention, just to correct you; P-Delta is not a Analysis it is a effect because of lateral loading that we do need to consider in tall building structures...
And we can take windward and leeward cofficient factor also in designing ratger then calculating the windload manually ?
Yes, you can... but in Force Coefficient Methods everything is in under control of all conditions and we get to know what exact load we are applying.
Why you use program calculated time period .Time period from program calculated and approximate method value is different .So which option is best for analysis ?
if you want to be conservative you can use time period by which you will get higher value of sa/g that may be program calculated (modal analysis) or imperial as per code....
but for real projects you should go with imperical time period as per codal formula that may depends on type of building: bare frame, rc shear wall, or other
What does an earthquake load in x+0.05e means? is it essential to consider that. pls guide.
if you are doing dyanmic analysis then it may not needed... for static it is essential...
At 11:44 time of defining mass source you have check mark to "additional mass", but not to "adjust diaphragm lateral mass to move mass centroid by". what is concept behind that?
alternatively when to apply check mark on option " include vertical mass".
*Mass Source in ETABS*
*• Element Self Mass:* Self Weight of Structure (by considering Model Part w.r.t. Materials Properties & Applied Loads under Dead Load Pattern)
*• Additional Mass:* It includes Loads like Cladding, etc.
*• Specified Pattern:* This Option Enables Designer to Consider Specific Pattern with control over Multiplier which helps to consider approproate ammount of live load
*• Adjust Diaphragm Lateral Mass:* it can able to give eccentricity w.r.t. diaphragm, mostly used for huge-complex structures & for research work
*• Include Lateral Mass:* in this case Mass Source Component X & Y are considered by software
*• Include Vertical Mass:* in this case Mass Source Component Z are considered by software (this are almost negligible so for most common structures it is untick; if you tick this then Base Shear is increase by 1% to 2%)
*• Lumped Storey Mass at Story Level:* Basic Approach of Calculation of Earthquake Load
hope your doubts are clear with this....
@@AkshayThakur very well explanation sir..much appreciated.
it would be so useful if you clear one more doubt - you wrote if tick the "Adjust Diaphragm Lateral Mass" option then it will consider the eccentricity.
my question is that we already consider one eccentricity at the time of defining load pattern ( EQ-X + ecc.) also another eccentricity at the time of assigning diaphragm ( to know distance between Center of mass and centre of rigidity), then which type of eccentricity is considered by software if we tick the above said option.
• Eccentric Earthquake Load is for Accidental Torsion....
• Adjust Diaphragm Lateral Mass is for to Adjust Location of Mass Source w.r.t. Diaphragm; where, mostly for common regular building structures with uniformly loaded floor it is not required...
*Actual Torsion* = Difference between CM & CR; it is for to check the Floor Mass w.r.t. Floor Rigidity...
*Accidental Torsion* is the Eccentric Earthquake Load in ETABS cause change in Earthquake Load in Structural Members
*Adjust Diaphragm Lateral Mass* is for Location of Seismic Weight w.r.t. Diaphragm which affect the Earthquake Load and so EL & ELe will also change respectively....
*Everything has its own Importance, the things is what to consider w.r.t. structural conditions is need to consider...*
@@AkshayThakur thanks a lot sir..
Sorry Sir , Self weight assigning is also available in staad pro , Y-1 , Check That.
yeah, but not the way it etabs; in etabs we have full control over materials properties than staad.pro
sir, in the excel file you shared(design of RCC building as per IS by ETABS) WL in X direction is 21KN at floor 1 n 11 at head room roof. bt here u r assigning it in reverse i.e. 21 at head room roof... How ????
It is because of effective height.... height is calculated for wind load at story for half of above part and half below.... whereas on over head room slab no any storey so half height is considered as effective heights at top storey.... hence the value is less....
for opimizing load calculations you need to also consider width of head room appropriately for that storey.... which i have not done in video 4.3 in the same course....
Check the Video "4.3 Manual Wind Load calculations as per IS 875.2-2015" for this....
*we calculate wind load in the asending order from 1st storey to top, but it ETABS we need to input reverse because in user load wind load pattern table starts from top storey to lower one....*
@@AkshayThakur yess...due to less effective height force value at top storey is less than other floor, but here in video at 5.24 value at top storey inputed is more than other floor thats contradicting waht calculated manually in excel sheet which u shared
Sir what if we consider eccentricity in x and x direction earthquake load kn single case
you can, ETABS results will not differ but for defining load combination manuallly you will get problem, but if you are go with default design combo then ETABS will consider all things...
my suggestion is define seperate case so that you can check behaviour of particular case...
what if we use IS code instead of user load in wind load calculation?
Need reply sir.🙃
there are two approaches to calculate wind loads for linear static analysis one force coefficients and other is pressure coefficients
If you choose, Wind Load as per IS code in Load Pattern then you have to find exact Cpe & Cpi (external and internal presure coefficients) values, those are easy to calculate for truss structures only, if you can do so for building considering opening and all then you can go with that as well....
in the mention procedure of video i have calculated wind Load by force coefficients....
you can go with any method but make sure all the code parameters are correct as per method...
@@AkshayThakur can I apply the force coefficient method for high rise? How the high rise building analysis differ from the method you provideded in this course of G+3 building?
Need reply sir...😊
for tall buildings generally wind forces from wind tunnel testing are used or otherwise gust factor approach is used, which is the further advanced procedure of force coefficients method...
generally for shed type structures pressure coefficient method is used
for general building structures force coefficient method is used
for tall buildings gust factor method is used or otherwise wind tunnel test data is used....
While defining the mass source, why we have not taken into consideration the lateral loads and their multipliers??
Mass Source is used to calculate Lateral Earthquake Force... & as per Guidelines of IS 1893.1-2016 we need to consider full dead load and part of live load....
my advice is that, if you haven't idea about manual calculations for earthquake load as per IS 1893.1-2016 then read the basic literature and then come to software analysis.... becuase before inputing any data in software the thing is you should have solid understanding over concepts....
OK sir...I will surely consider that... Thank You
@@AkshayThakur how to apply mass source if there are live loads are acting is both greater and also equal or less than 3
Do we need to define two mass source in that case.
@@Sankalp-Art-Work then create two load patterns and for LL =& 3 0.5 should apply...
why do we want to input eccentric earthquake load...
to check for Torsion, as per Cl.7.8 of OS 1893.1-2016