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?
(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
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.
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
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
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..
Indeed. Check this video for a deeper look on RC retaining walls. This is where every single action gets addressed. ruclips.net/video/zYg_By_0a6I/видео.html&ab_channel=CivilEngineeringEssentials
You are most welcome. Please note that there is even a deeper dive video on this channel, found under: ruclips.net/video/zYg_By_0a6I/видео.html Stay tuned for more content. Also, if possible, suggest this channel to your friends. Regards, CEE
You are most welcome. There is even a deeper video on this topic: ruclips.net/video/zYg_By_0a6I/видео.html&ab_channel=CivilEngineeringEssentials Also, if possible, suggest this channel to your friends. Regards, CEE
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
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.
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.
I think I agree with you. Actually, I had a deeper video about this topic. You can find it under: ruclips.net/video/zYg_By_0a6I/видео.html&ab_channel=CivilEngineeringEssentials
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?
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
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?
Hi there, it is modeled as a shell. Also, please note that there is an even deeper video on this channel found under: studio.ruclips.net/user/videozYg_By_0a6I/edit
@@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.
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
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.
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.
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
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
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
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?
(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
@@CivilEngineeringEssentials , 🥰, looking forward to. Thanks again for your wonderful work.
@@CivilEngineeringEssentials Does robot take into account the cohesion of the soil while calculating the stresses ?
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.
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
@@CivilEngineeringEssentials thanks
TBH, great detail, the best tut for me atm, PLZ keep your great work
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
Amazing, thank you !
You are most welcome. Stay tuned for more content, CEE
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..
Indeed.
Check this video for a deeper look on RC retaining walls. This is where every single action gets addressed.
ruclips.net/video/zYg_By_0a6I/видео.html&ab_channel=CivilEngineeringEssentials
REally good stuff
oh thnx a lot, it honors me that you like those videos. Please stay tuned for more content. Regards,
CEE
Great video, very helpful, Thanks
I am glad you liked it. Stay tuned for more 👍
Great video thanks!
You are most welcome.
Please note that there is even a deeper dive video on this channel, found under:
ruclips.net/video/zYg_By_0a6I/видео.html
Stay tuned for more content. Also, if possible, suggest this channel to your friends.
Regards,
CEE
Thank you
You are most welcome.
There is even a deeper video on this topic:
ruclips.net/video/zYg_By_0a6I/видео.html&ab_channel=CivilEngineeringEssentials
Also, if possible, suggest this channel to your friends.
Regards,
CEE
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
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.
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.
I think I agree with you. Actually, I had a deeper video about this topic. You can find it under:
ruclips.net/video/zYg_By_0a6I/видео.html&ab_channel=CivilEngineeringEssentials
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?
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
Great..
Happy you liked it. There are more in depth videos on this channel so check them out
Thank
Most welcome. Stay tuned for more content.
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?
Hi there, it is modeled as a shell.
Also, please note that there is an even deeper video on this channel found under:
studio.ruclips.net/user/videozYg_By_0a6I/edit
@@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.
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
Could you include links to the books you mentioned?
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.
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.
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?
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
Good job
Glad you liked it👍
alhamdulillah
thank civil engineering essentials
You are most welcome my brother. I hope you all the best.
This is good!
Glad you liked it.
Help spread the word 👍
From where you got the combinations ?
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
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.
Hello there, sure thing. I will plan a nice video for earthquakes next week.
Glad you liked the video
@@CivilEngineeringEssentials ok thank y bro
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
Hi there, doing good.
I think you are right. I will try that. Thnx a lot and all the best,
CEE