Thank you. I’ve been looking for just such a video to show in class. Didn’t have any luck when I search, then a few weeks late this shows up as a recommendation. Perfect.
Mike - Very good point! I forgot about that! A deadman anchor (basically a large chunk of concrete) placed far behind the wall is another great option. Thanks for the reminder!
The tiebacks are installed by drilling a small diameter hole (4-6 inches) back into the hillside. A special drilling machine drills this hole sideways, downward at an angle of 15 to 45 degrees using a screw auger that is hollow in the center. Next, a piece of steel rod is inserted down the center of the hollow screw and grout/concrete is pumped into the hole. The grout prevents the hole from collapsing and hardens into concrete around the steel rod. Pretty cool, huh?
yes - the wale is the horizontal beam between two of the vertical beams. The wale minimizes the number of tiebacks that are required. Every single one of the vertical beams must be secured with the tiebacks into the hill, and each one would need a tieback. But, by placing a tieback connected to a wale, the wale can then secure TWO vertical beams.
Awesome video! I am looking to cost out the difference between using Rakers or tie backs - and how much each would cost overall in a project. Specifically the property is 147 feet long and beside it will be a development with about 2 stories of below grade parking. Using average spacing of tiebacks and taking into account the below grade is 2 stories, how much would that cost to build that out using tiebacks along that one wall? And conversely - without using tiebacks what would the same scenario cost if they used rakers for that wall? Im just looking for ball park figures +-. If you could advise that would be greatly appreciated!!
An engineer can calculate that, and it is quite involved. The part nearest the wall does not "count" as anchor, because ity is moving with the wall. Stronger soil will require a smaller diameter around the anchor and a shorter length, once past the "unbonded zone" close to the wall. Best results are when anchored portion is in bedrock. Design will show number and spacing of anchors, location, angle, length, strand diameter, and wale (horizontal beam) size. So, there's no a simple answer, sorry!
Seems you were saying you put the sleepers in top to bottom, as you dig out behind the wall line. Is that right? If so, you'd have to cut the sleepers short enough that they could potentially fall out. Are they screwed to the C post soldiers? btw. Great videos, I run a retaining wall company in Australia.
Hello, I have a question. I work for an excavation company specializing in earthwork. Recently we were tasked with tieback removal and unfortunately we lost one of them during the process. my question is, what problems does that create structurally? If a tieback is designated for removal later and a portion of it is removed but the rest remains in the bore what happens to the structure? Thank you.
If a tieback is no longer needed for the purpose of holding the wall back, then leaving it in place shouldn't be detrimental to the wall. The only problem might be if the remaining tieback is going to interfere with some other construction back in the hillside. (I've not heard of removing tiebacks before, so I'm really interested in why, and how, you did that!) Sounds interesting! Email me more if you have time: Joek@RetainingWallExpert.com
Is the tie back a part of permanent structure? But I remembered when I was having training in a construction company. People talked about touching up blindside waterproofing after removal of tie back. I was confused.
Muhammad, check out this video that shows how lagging is installed. Usually in 5' sections. They go "down" by going "up" in 5ft sections... If that makes any sense... ruclips.net/video/tiJLFOCvUxc/видео.html
You are right. Most of the time, the lagging is NOT placed behind the flange, but is attached to the face. This is done by welding small (6-inch long) threaded rods to the face of the beam. A small steel plate with a hole in the center acts as a washer holding back the timber.
Al ShangriLa True - good catch! Yes, these beams were installed into pre-drilled holes. The holes were filled with lean concrete which was chipped away from the steel beam as the excavation was made downward. So, yes, these beams were not "driven". Thanks for watching!
Al ShangriLa STEEL IS NEVER "CAST-IN-PLACE" Cast-in-place refers to concrete being poured on site, steel is fabricated at the steel shop, not at the job site
Al ShangriLa The steel beams ARE CAST-IN-PLACE. They were cast into concrete that was placed ON-SITE. Just like any steel rebar can be cast-in-place into a retaining wall on-site. The beams were NOT driven into the ground. They were "cast" into drilled shafts that were filled with concrete after the steel beam was placed into the open shaft. So, YES, the beams WERE "CAST-IN-PLACE".
Thank you for making the video not too long but extremely informative I always appreciate somebody that’s knowledgeable in their trade. Thank you
Thank you. I’ve been looking for just such a video to show in class. Didn’t have any luck when I search, then a few weeks late this shows up as a recommendation. Perfect.
i am an architect student and i am learning these from you! thank you! teach us more!
wow, this early in youtube you did make a very good and informative video. Hope you are doing well in life sir
Mike - Very good point! I forgot about that! A deadman anchor (basically a large chunk of concrete) placed far behind the wall is another great option. Thanks for the reminder!
The tiebacks are installed by drilling a small diameter hole (4-6 inches) back into the hillside. A special drilling machine drills this hole sideways, downward at an angle of 15 to 45 degrees using a screw auger that is hollow in the center. Next, a piece of steel rod is inserted down the center of the hollow screw and grout/concrete is pumped into the hole. The grout prevents the hole from collapsing and hardens into concrete around the steel rod. Pretty cool, huh?
If only Bob Vila understood the drilled shaft and socket method he would be my hero just like you.
yes - the wale is the horizontal beam between two of the vertical beams. The wale minimizes the number of tiebacks that are required. Every single one of the vertical beams must be secured with the tiebacks into the hill, and each one would need a tieback. But, by placing a tieback connected to a wale, the wale can then secure TWO vertical beams.
thank you for this video I under stood from it more than what our professore had explained in the construction process coures
Awesome video. Very helpful
Awesome video! I am looking to cost out the difference between using Rakers or tie backs - and how much each would cost overall in a project. Specifically the property is 147 feet long and beside it will be a development with about 2 stories of below grade parking. Using average spacing of tiebacks and taking into account the below grade is 2 stories, how much would that cost to build that out using tiebacks along that one wall? And conversely - without using tiebacks what would the same scenario cost if they used rakers for that wall?
Im just looking for ball park figures +-. If you could advise that would be greatly appreciated!!
I know this video is old as dirt now (no pun intended lol) but nicely explained.
Lol
An engineer can calculate that, and it is quite involved. The part nearest the wall does not "count" as anchor, because ity is moving with the wall. Stronger soil will require a smaller diameter around the anchor and a shorter length, once past the "unbonded zone" close to the wall. Best results are when anchored portion is in bedrock. Design will show number and spacing of anchors, location, angle, length, strand diameter, and wale (horizontal beam) size. So, there's no a simple answer, sorry!
Seems you were saying you put the sleepers in top to bottom, as you dig out behind the wall line. Is that right? If so, you'd have to cut the sleepers short enough that they could potentially fall out. Are they screwed to the C post soldiers? btw. Great videos, I run a retaining wall company in Australia.
Also if reaching the bedrock is not an option, you could use a deadman anchor.
very cool!....I am a contractor and love all things construction!....
Hello, I have a question. I work for an excavation company specializing in earthwork. Recently we were tasked with tieback removal and unfortunately we lost one of them during the process. my question is, what problems does that create structurally? If a tieback is designated for removal later and a portion of it is removed but the rest remains in the bore what happens to the structure? Thank you.
If a tieback is no longer needed for the purpose of holding the wall back, then leaving it in place shouldn't be detrimental to the wall. The only problem might be if the remaining tieback is going to interfere with some other construction back in the hillside. (I've not heard of removing tiebacks before, so I'm really interested in why, and how, you did that!) Sounds interesting! Email me more if you have time: Joek@RetainingWallExpert.com
Is the tie back a part of permanent structure? But I remembered when I was having training in a construction company. People talked about touching up blindside waterproofing after removal of tie back. I was confused.
Yes - the tieback is a permanent feature!
ps. how do you know how far to drill and how do you know what the soil conditions are???
so how do you get the tie backs in? Excavation?
How could we exactly install timbers lagging while going downward? I could understand that point.
Muhammad, check out this video that shows how lagging is installed. Usually in 5' sections. They go "down" by going "up" in 5ft sections... If that makes any sense... ruclips.net/video/tiJLFOCvUxc/видео.html
You are right. Most of the time, the lagging is NOT placed behind the flange, but is attached to the face. This is done by welding small (6-inch long) threaded rods to the face of the beam. A small steel plate with a hole in the center acts as a washer holding back the timber.
Cool
I-beams or H-beams?
H - beams. Most commonly HP14x73 or HP14x89 beams are used.
Those wales certainly make the retaining wall look real ugly!
Those I beams are 'Cast-in-Place' not 'Driven'. Just sayin' . . .
Al ShangriLa True - good catch! Yes, these beams were installed into pre-drilled holes. The holes were filled with lean concrete which was chipped away from the steel beam as the excavation was made downward. So, yes, these beams were not "driven". Thanks for watching!
Thx for posting. Great tutorial. Kudos!
Al ShangriLa STEEL IS NEVER "CAST-IN-PLACE"
Cast-in-place refers to concrete being poured on site, steel is fabricated at the steel shop, not at the job site
Al ShangriLa The steel beams ARE CAST-IN-PLACE. They were cast into concrete that was placed ON-SITE. Just like any steel rebar can be cast-in-place into a retaining wall on-site. The beams were NOT driven into the ground. They were "cast" into drilled shafts that were filled with concrete after the steel beam was placed into the open shaft. So, YES, the beams WERE "CAST-IN-PLACE".
Thank you . Note I will not need to write up a non compliance :-)
Aren’t the soldier piles considered “H” piles ?
yes - exactly. H piles. They have a wider flange than an I-beam.