Static Seismic with IS1893 - pt.3: Design Horizontal Acc. Coeff.(Ah) || Sa/g, Z, R, Response Spectra

In this video, I will cover an important topic, how the design horizontal acceleration coefficient Ah is calculated and used for static seismic analysis. This Ah value depends on several factor including site specific condition and building related parameter. I will discuss all these factors used to calculate the Ah value.
For analysis and design of any structure (concrete, steel or composite) which is in low or high seismic prone area, we need to perform a detailed seismic analysis and based on the analysis results, go for member/connection design. Static seismic analysis is one of the easiest method of earthquake force consideration but it is not only limited to that. For dynamic analysis and seismic detailing, we need static seismic inputs. There are 15 different inputs required for IS1893:2016 code and if any incorrect input is assigned, that may lead to unsafe design.
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Part 2: Basics of Design Base Shear || Criteria, VBmin, Seismic Weight -- • Static Seismic with IS...
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Part 4: Loads & Combination || Non-orthogonal Frame || Auto-Load Combo -- • Static Seismic with IS...
For more details on Seismic analysis, check this video --
• Modelling for Seismic ...
Also check this playlist --
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[@soumikmandal2647]

You have the skill to teach. Thank you for the simplified explanation

[@dipeshchauhan5196]

Excellent explanation ❤

[@lukog9622]

God level explanation. Keep posting such videos which actually help budding engineers like me.

[@karthik013013]

Very detail explanation thank you and hope more videos will guide us

[@shaikheslamulhoque8611]

very nice

[@nooranistores8015]

Thanks for uploading video that are very helping for us, sir I requested to you that kindly upload a video on perform analysis command, when to use perform analysis only/p delta analysis /perform buckling analysis/perform direct analysis,
Also what's the meaning of Perform analysis No/print all/static check/mode shape etc.
Sir, also make a video on full procedure of dynamic analysis by time history/modal time history method. Thank you sir...

[@honey26singh]

Sir please make video on basement wall design in staad pro

[@binayaksamanta863]

Yes

[@aleximmanuel3621]

Great topic an damn well explained . Ther is just one thing which i earlier to highlighted in forums of Bentley , which is why staad has provided only one value for R in seismic defination it should rather be for two horizontal direction , taking case of PEB structures which has been the hot topic over last few webinars , we need two R factors . For American code has two r factors in staad defination , the same could be for Indian code too right ?? Basicallt having two different ah values for two hot directions. We need to scale it in order to implement two different R values.

[@surojit_ghosh]

You are correct, and it is fairly common to have two different framing systems for any steel structure. I am not sure why it is not there for IS code, only way to consider this - using different load factor which is not accurate as several checks (like VBmin) will not be performed. I will suggest you to post this in Ideas channel (communities.bentley.com/products/ram-staad/i/ ) and see, what the product management think about this.

[@aleximmanuel3621]

@@surojit_ghosh the problem also is even consultant ofthen in project specification mentions one value for R . they also speak the staadpro language . Lesser R value will give more seismic forces and vice versa, which is why then often certain straight forward concepts becomes too complicated even for most of the engineers.

[@paydaycheting2207]

Hi iam working in a project where even after 400modes in response spectra getting nearly 50% missing mass. How can i account for this lost mass

[@surojit_ghosh]

You can use Load dependent Ritz vector method for Eigen solution, by default subspace iteration is used which causes this problem. Change the eigen solution method from Analysis > Miscellaneous command option.

[@shubhampatwardhan3212]

How to calculat importance factor why its 1.5 why is not1.6 or 1.7

[@surojit_ghosh]

This value is available in relevant design guide, for IS code, check cl.6.4.2 and Table 8 of IS1893 (part 1): 2016.

[@thineshm5386]

Please write your Mail id sir , need some help regarding irregular structure