Design of RC Retaining Walls (Simplified) in Autodesk Robot

[@donaldkhanye2323]

Thank you CEE 💯, “…. the opportunity to see your thought process in detail, and the step-by-step suffering that you endure 😊 …..” are indeed necessary and they do make the tutorials feel that much more practical and engaging. Questions: 1. The foundation “length” in the final RSA design is about 4.2 meters. Braja M Das proportioning dimensions guides for this length are 0.5 to 0.7H (1.5 to 2.1 meters). I am concerned that 4.2 meters does not “feel right, it feels too long” are you not worried about this dimension? 2. @ about 30h11 you explained the importance of the soil weight above the heel; @ about 26h30 aren’t the reactions of the wall support you mentioned not only representing the HORIZONTAL components of the soil above the heel and not the VERTICAL components? I am thinking that maybe the VERTICAL component of the soil weight above the heel should be model into the design of the retaining wall foundation somehow? What are your views?

[@CivilEngineeringEssentials]

(Fun fact: the discussion made me rename the video as - Simplified- because you gave me amazing food for thought. I think there is something even better to be prepared next week. + You will get a shout-out at that moment ^_^. It is next week because I already scheduled a Video for 08.09 about modeling swimming pools.) As for Q1, I totally agree. The reason why the retaining wall was this large is because of the bearing capacity. The loads on the foundation are eccentric, and cause higher pressure on the toe and even uplift in the heel region. Robot suffers in not taking some points about the heel into account. I will address this issue in a more detailed video in the future. This is also point 2 for point 2: The reactions you see on the foundation horizontal soil pressure and moment. the vertical force you see here is due to the weight of the wall. This is what I mean by "there is no full module that designs retaining walls in robot, and the engineer has to make it in two pieces" However, you gave me an amazing idea, and I will post something about this next week after doing some research. I am betting that one can define the soils weight above the heel in the geotechnical soil characteristics by putting the soil height on one side 3meters. I still have - however - to check the accuracy of calculations. I will prepare a video about this. Your question is amazing, and I will put it in the description Regards, CEE

[@donaldkhanye2323]

@@CivilEngineeringEssentials , 🥰, looking forward to. Thanks again for your wonderful work.

[@BA-gp7sr]

@@CivilEngineeringEssentials Does robot take into account the cohesion of the soil while calculating the stresses ?

[@nhanvohoang8935]

TBH, great detail, the best tut for me atm, PLZ keep your great work

[@CivilEngineeringEssentials]

There is even a better video that compares and digs deeper in the RC retaining wall design. Take a look on that too. Happy you liked it. Please help the channel grow by suggesting it to other friends and encouraging them to subscribe. Regards, CEE

[@benjaminlavigne2272]

Amazing, thank you !

[@CivilEngineeringEssentials]

You are most welcome. Stay tuned for more content, CEE

[@parkiegras2653]

Great video thanks!

[@CivilEngineeringEssentials]

You are most welcome. Please note that there is even a deeper dive video on this channel, found under: kzbin.info/www/bejne/sIrKkHWvlJWUbKs Stay tuned for more content. Also, if possible, suggest this channel to your friends. Regards, CEE

[@niisarpei3676]

Great and Intensive Presentation CEE. We need to discuss a lot of things, which am sure will unfold as the course keeps taking shape. I personally size my basement/retaining wall this way 1. height of wall/15 for wall thickness. 2. For the base I usually do a width of 0.6* wall height and proportion 1/3 and 2/3 to the toe and heel side respectively. The earth on the toe side is usually neglected for conservative reasons I personally think these personal provision is quiet in line with your reference material. However, in loading the wall and the base, the BS 8110 treats the earth on the heel side as DL and recommends 10kN/m surcharge weight on the heel side to account for LL which is distributed in a rectangular shape horizontally and vertically to the wall and base. You are right in the analysis of basement walls, as usually the moment and shear diagram depict that of a propped cantilever due to the adjoining frame on the suspended ground floor. I wish to see how to add the surcharge live load on the wall and base of the retaining wall. Your model is quite conservative (300 thick wall for 3000mm height of wall) and simplified in loading (1.4 DL) hence the nominal reinforcements in the wall. I believe in future tutorials we can discuss more on how Robot displays results for walls and floors as It’s might be misleading and confusing in representation of the results. Thank you Have a lovely day Sir Regards.

[@CivilEngineeringEssentials]

Hello there, I am glad you liked it and it sparked a lot of ideas and topics to be discussed. I am planning a (deep dive) video for the retaining walls next week, since you and another dear subscriber (Donald Khanye) have raised a lot of valid points that I want to address. I think I will be modeling like 3 to 4 retaining walls side to side and talk about the various points raised, with comparisons and more information. Your suggested dimensions are somehow near what Braja M Das suggests. I will investigate them and compare both in the next video. You both gave me a lot of food for thought and I have to script a nice concise and engaging script to be filmed for next week ^_^, so stay tuned. I have put it on my schedule for next week, because I already scheduled a swimming pool modeling video for the 08.09.2022 + I am expecting the retaining wall video to be long. Regards, CEE

[@niisarpei3676]

@@CivilEngineeringEssentials thanks

[@hamidanghaie5197]

Great video, very helpful, Thanks

[@CivilEngineeringEssentials]

I am glad you liked it. Stay tuned for more 👍

[@lmthunzi]

REally good stuff

[@CivilEngineeringEssentials]

oh thnx a lot, it honors me that you like those videos. Please stay tuned for more content. Regards, CEE

[@aliahmataliahmat4440]

Great..

[@CivilEngineeringEssentials]

Happy you liked it. There are more in depth videos on this channel so check them out

[@hamidmajeedabdful]

Thank you

[@CivilEngineeringEssentials]

You are most welcome. There is even a deeper video on this topic: kzbin.info/www/bejne/sIrKkHWvlJWUbKs&ab_channel=CivilEngineeringEssentials Also, if possible, suggest this channel to your friends. Regards, CEE

[@walshi2292]

Good job

[@CivilEngineeringEssentials]

Glad you liked it👍

[@somnangvat8599]

Thank

[@CivilEngineeringEssentials]

Most welcome. Stay tuned for more content.

[@sentumbwefarouk9247]

thank you so much doctor, just a quick ask, WHY DO U USE FLOORS FOR RETAINING WALLS, INSTEAD OF THE ROBOT WALL, whats their characteristics and if possible could use the "wall" and vary their results, kindly? thank u

[@CivilEngineeringEssentials]

That is a very good question. Walls and floors will have the same analysis. However, when you design them, robot walls are going to be treated as shear walls. With boundary elements In robot walls, the load is assumed NOT to be perpendocular to its plane surface. Like a shear wall. So its design is different than floors, where you have the assumption of forces perpendicular to its plane surface 👍🌹 Hope it makes sense. Feel free to ask again if need be.

[@levichidera8350]

This is good!

[@CivilEngineeringEssentials]

Glad you liked it. Help spread the word 👍

[@vukvukanic1095]

Great video, one question. Are you modeling the wall as a floor in order to have moment actions part of the design withing the provided reinforcement module?

[@CivilEngineeringEssentials]

Hi there, it is modeled as a shell. Also, please note that there is an even deeper video on this channel found under: studio.kzbin.infozYg_By_0a6I/edit

[@vukvukanic1095]

@@CivilEngineeringEssentials Yes, I watched both of them. Actually if you look at 7:57 you can see the properties, Structure object property=Floor, and when you export it the wall to provided reinforcement module it's categorized as Floor. I think you are referring to the Calculation model property which is Shell.

[@CivilEngineeringEssentials]

Oh I see. I misunderstood your question. Sorry about that. Yes, indeed, I used the "floor" command. you can make it a "wall element", It will work. Now I still have not talked about wall elements in this channel, but this will change very soon. There is a basement video I am preparing, in its second part, it will be designing the basement wall once as shell and another time as wall. So stay tuned (Part 1 is about the modeling, part 2 is about the design) Part 1: this friday Part 2: the next Regards, CEE

[@tukangsipilofficial1362]

alhamdulillah thank civil engineering essentials

[@CivilEngineeringEssentials]

You are most welcome my brother. I hope you all the best.

[@Howtodoanything99]

Good day, thank you for the video. Could you please assist me, I’ve done the example exactly how you did it in the video, but I’m getting an error when i run the calculations. The errors are (1). Example not specified. (2) no supports. (3) the load has not been distributed correctly. How do I fix them?

[@CivilEngineeringEssentials]

Hello there and good day to you too. Please make sure you select "Shell" when you define the wall of the retaining wall. If you use "curtain wall" or something else, this error occurs. Sorry for the late reply, Regards, CEE

[@BA-gp7sr]

Thank you for your efforts on these vidoe's but i have a question why did you use the floor icon instead of using the wall icon?

[@CivilEngineeringEssentials]

Because Robot's reinforced concrete design module designs (walls) as shear walls with boundary elements and so on. Of course retaining walls do not have those

[@عازفالليل-ك6ق]

Thank you very match..... I want check for sliding by robot pleas my friend explain it or tell me if that any video on youtube explai it.......

[@mmrm250]

Could you include links to the books you mentioned?

[@CivilEngineeringEssentials]

Hi there, unfortunately, I am not allowed to do this due to copyright laws However, you can google anything by writing: bookname filetype:pdf and all possible pdfs will appear in the search PS: Sorry for the late reply. I had a ton of things to finish and now I am gradually getting back

[@safiyamunther4061]

13:09 dear sir, I noticed that Robot doubles the the pressure value after its being assigned to the panel. Do you know why? Personally I prefer to calculate and assign the soil pressure manually until I figure out why this issue happens.

[@CivilEngineeringEssentials]

I think I agree with you. Actually, I had a deeper video about this topic. You can find it under: kzbin.info/www/bejne/sIrKkHWvlJWUbKs&ab_channel=CivilEngineeringEssentials

[@chunhinchoy2056]

can i add shear pin(s) under the retaining wall in this software?, if the retaining wall is sitting on rock, i decided to add shear pin(s) to resist shear and tension, which the stiffness of rock and shear pin is not the same, thanks for taking the time to read this msg.

[@CivilEngineeringEssentials]

In Robot, applying shear pins in the model is - unfortunately - not possible. However, you could think of adding a linear spring to model this pin. I hope you enjoy the videos. Stay tuned for more.

[@slavg2339]

What if RS define wall foundations (24:01) perpendicular to the panel in every node?

[@demitri59]

From where you got the combinations ?

[@CivilEngineeringEssentials]

If you use the design module to generate the combinations, then those are done automatically using the Code you defined. If you want to see you definition, then please go to: Tools -> job Preferences. Expand (Design Codes) Under (Loads) you will find the used codes to auto-generate the combinations. Regards, CEE

[@structureOG]

Your heel section is much longer than necessary because of the way you have used robot (no fill pressure is applied to the heel footing section). This also means settlement and bearing capacity calculations do not include the 3m of fill (60kPA - 6 ton per m^2!!!) on the footing..

[@CivilEngineeringEssentials]

Indeed. Check this video for a deeper look on RC retaining walls. This is where every single action gets addressed. kzbin.info/www/bejne/sIrKkHWvlJWUbKs&ab_channel=CivilEngineeringEssentials

[@salaheddine6721]

thank you it's great video please a next time show me how to applicate a load of earthquake at this wall and thank y again.

[@CivilEngineeringEssentials]

Hello there, sure thing. I will plan a nice video for earthquakes next week. Glad you liked the video

[@salaheddine6721]

@@CivilEngineeringEssentials ok thank y bro

[@majidjassim933]

Hello, how are you? If you can speak slower so that non-English speakers can understand what you are saying, so that your viewing increases and everyone understands .... Thank you, the content is excellent

[@CivilEngineeringEssentials]

Hi there, doing good. I think you are right. I will try that. Thnx a lot and all the best, CEE