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- เผยแพร่เมื่อ 16 ก.ย. 2020
- Team Kestava tackles more seismic design problems using ASCE 7-16 chapters 11 and 12, and this time its all about finding story shear for multi story buildings. This example problem goes through the steps on how to find seismic criteria of a structure based on a few preset parameters.
The team shows you how to calculate base shear of a multi story structure and then we walk through how to distributed that base shear into individual story shear. Its our first steps into designing a skyscraper and highrise!
We touch on:
seismic mass
base shear (V)
story shear (Fx)
Cs
Response modification factor (R)
Importance factor (I)
Period of our structure (T)
By the end of our seismic lessons ASCE 7-16 WILL be your friend.... that still eats your food.
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I love how you try to add some fun moments in your tutorials!
I try haha, gotta like what you do!
You are a life saver. Thank you!!!
Got your back Jay. spread the word that Team Kestava is the place to be.
I have a Presentation in a few hours and this video has summed up my whole semester project. Thank you 🇵🇬
Wonderful!
It's shoveling!!! Thank you so much.
You bet Milestone!
Fantastic video. Thanks a lot.
Glad you liked it! let me know if you have more topics youd like covered
Very thank 🙏
Thank you my friend 🙏 can you make a video on how to read the soil report and how to decide which foundation system we should use depending on that soil report? And how to find bearing capacity then ? And for sure if you have time and if this topic is within your majority
great video sir, tanks.
Appreciate the kind words Jose! Let me know anytime what type of questions you have and ill add them to the list of videos!
Can you make a video on how to distribute these forces on shear walls in each floor plan ? Thank you 🙏
Great video thanks
No problem 👍
Hey I have a question about the determining of Seismic Design Category(SDC), what if for Table 11.6-1 and 11.6-2, the SDC obtained from those are different? from which table do we choose our SDC then? Thank you!
i lost it when michael scott started shouting
Thanks for the video, I have some questions at this point: (Quest.1) as it says here that time period is 0.2 for short and 1 sec for tall buildings. Are these time fixed values? Isn't is very common to have time period way greater than 1 sec. How we design for buildings having more than (say) 30 stories? (Quest 2) isn't Time period a function of type of building material i.e. concrete, timber, steel, type of soil strata on which it rests, number of stories etc. So how we can generalise just 2 time period when there are number of factors which can change the time period of a building? Thanks..
would this or any part of be a PE Civil Structural question, and which part you may think it would be ?I understand that 12 story building is a bit of a stretch at the exam, but I think the first part of looking up the formulas from ASCE 7-16 may be a good question at the exam, your feedback is appreciated.
Would you happen to know why for seismic, when calculating the base shear, people often divide by 1.4? I’ve been told it’s going from ultimate to ASD?
Hey Jeff, its a conservative approach to switch back and forth between ASD and Ultimate as youve stated. this comes from the load combination in chapter 2 of the ASCE 7-10/16 provisions. Ultimate = 1.0Eh and ASD = 0.7Eh. for JUST base shear that is a 30% difference so 1.3 might be more justifiable, however when talking about all factors of seismic design where DL is used in the calcs the ASD and Ultimate load cases get more complex and I believe 1.4 ROUGHLY translates between the two. again this is just a rough order of magnitude but should not be taken as gospel, otherwise it'd be in the code!
Thank you as I have watched the 3 parts earlier and follow through. Assume there are 16 columns totals on this structure, is the base shear V and W calculated are for one of the column only? I guess he won't answer and can someone who know answer this ?
Thanks for this incredibly helpful video! Why did you not calculate Fv and Fh for this problem? why did it stop at Fx? Can you explain...
video was just getting long and felt this was a good stopping point! thanks for watching as always!
I was wondering why we calculated the overturning moment at the 4th floor?
Hi Casey, I put that question in to show how you find OTM at each story. As we move down the stories the forces increase and you would need to design each story for the increase in forces. It was just to show not every story sees the same forces. great question!
6:48 What if it's C & D? Which category do I need to design with?
You'd still need to design with D. Great question!
@@Kestava_Engineering Thanks for the clarification. You deserve more subscribers! Keep it up.
@@TV-ws8mf Thank you for the kind words! spread the word, Team Kestava is growing baby!
Hi Rich, thanks for your nice video. Just want to know what is PGA used for. I was doing a design work, the employer's requirements said the minimum PGA used for design is 0.6g, but PGA has not shown up in your video so far.
Hi Kaihui - PGA stands for peak ground acceleration. PGA is the max ground acceleration that happens during shaking caused by an earthquake at a specified location. and since its the "peak" PGA refers to the largest recorded acceleration on an accelerogram. I havent used PGA much but ill have to get it incorporated into a video for you!
@@Kestava_Engineering thank you so much mate!
Hii sr can you tell me how to distribute storey shear to various vertical elements?
you have 3 options
1 - flexible diaphragm
2 - semi rigid diaphragm
3 - rigid diaphragm
Our case is rigid diaphragm
in your claculation S1 =0.4 & Site class D. so Cs should multiply with 1.5 as per ASCE 7-16 11.4.8. so Cs will be 1.5x0.0398 =0.0597. isn't it????
Awesome videos man really helpful stuff. I also watched your 3 part video and I was just wondering - why is it that the ground level w_x value in this video is 0 but with the other video it actually had a weight at ground level?