So whats the rule of thumb for operating a Vibrating Tamper Plate (mounted on excavator) near foundations? Can I operate this equipment within a couple feet of a home foundation or a building slab? If you wouldn't recommend being that close, what is the offset from a building that you would feel comfortable not to cause any damage to the foundation? fyi the excavator is a medium size 172HP
Welcome to the Forums BFH. We're going to need some more information. For starters - New foundation or old one? What type of soil? How close to the foundation? From the title it says 325, which is a decent sized excavator - 325FL, 325DL, 325C? There is a weight difference between those models for instance. Did you damage a foundation?
Dido cm A 325 and a hydralic plate is quite a bit of compaction I leaned a retaining wall with a backhoe and compaction wheel so anything is possible but we need details
Poured,reinforced,fully cured,green,braced,free standing,hollow blocks ,solid blocks,filled hollow blocks with without rebar. What do specs call for?
My apologies...…... I'm glad you asked for more info on the machine. Here, I was in such a rush to post, I gave you the info on our other machine. The one with the tamper is Kobelco 140sr. Weight is around 33,000 lbs, and 93 HP. As for the foundation.....Yes, they are claiming I caused some damage by operating the tamper within 2 foot of the corner, and there is indeed a crack in the floor in that corner. I was hoping to find other cracks in this floor, but unfortunately that didn't happen..... So much for the "Crack in every Bag" theory))), but its hard to say if that crack was there prior to my work. The foundation was laid in 2014, and is a monolithic (s) style, where the parameter is 12" - 14 " deep, and the pad is 6" thick. This is not below the frost line in PA, but whoever did the job, it does look good. The only crack in the floor happens to be where I ran the tamper. The crack is in the 6" floor portion, but does not extend into the thicker footer portion of the pour. From the inside, the cracks forms a perfect Isosceles Triangle with the back and side walls. The soil in this area is a medium to tight texture, with some clay and a little rocky. Drainage is pretty good. On a scale of 1-10, I'd give it a 8. I hope my description makes sense. Again, I apologize for the misinformation at first. ps. Thanks for the "welcome" This situation has been rather stressful, but I hope to become a familiar face around here.
apologies for the initial misinformation. (see post #5)
I'm no help but what part of pa are you from
I cracked a block foundation with a jumping jack once. When you tell the new guy to keep running it until the sand doesn't compact anymore, that foundation would have been completely collapsed and crushed every core before that jumping jack was done. That sounds like a completely different situation than yours. Are they saying you lifted the corner (forced too much soil under the slab)? or cracked it from vibration or what? I obviously pushed in a weak block wall from too much pressure, kind hard to understand how you cracked an on grade slab. And what are they expecting you to do about it? Even if they can prove the crack is new, kinda hard to prove you were negligent.
Tyler d4c..... I am near Knox Dale, which is near Brookville, PA}}}}
They were in the building when we were compacting. They are going with "excessive vibration" is what cracked the thinner 6" floor. They claim the building vibrated so hard, they expected to have more damage than there was. According to the property owner and his consulting engineer....Here is their 2 main points to substantiate "vibration" cracked the floor. 1) only the floor is cracked, and not the thicker parameter footer. Being the footer and floor are one solid pour, their engineer believes to crack the floor (by lifting, heaving or settling), the parameter "footer" would have to have a crack somewhere. It does not. 2) The engineer says the crack is very clean on both sides of the split. If the crack in the 6" floor was cause by LIFTING OR SETTLING to the stress point of failure, the top surface of concrete would be chipped and have small chunks missing. (Even I think there may be something to this point. I hate to say, it does sound logical)
Do you have any pictures you could post?
I have to PAUSE for an off topic post to this thread. The main point to this post, was to get a little education on the Do's and Don't to using a Vibrating Tamper plate. What is the general "rule of thumb" for using a 33k lb machine so close to a foundation......ect…..ect. What I'm going to say doesn't affect the main topic of the thread, but you may find it amusing....or dumb on my part. Before this building was erected, the neighboring property owner built a new home. When hooking up his lateral, he crossed over the corner of the adjoining property owner by approximately 8-9 feet (now the owner of the cracked floor). So now 50 years later, I'm digging up the lateral to be replaced, only to find I'm coming within 2 foot of this building. As Paul Harvey would say......and there is "The Rest of The Story"
Pictures I had were on a flash drive, which is in the hands of legal council. He said he would copy them to his computer and return the drive. I have a meeting with him on Monday.
I'm out in the DuBois area! As to the operation, i really wouldn't want to use vibrating equipment next to the foundation. However, I'm curious to see what the pictures look like but it does seem strange that the 6" piece cracked but it doesn't extend into the thicker sections. I wonder if there is any re-bar in that monolithic pour. If there isn't, I wonder how they explain away temperature and shrinkage cracking......
Temp and shrinkage cracking was a thought that crossed my mind as well since the slab is not below the frost line. However I live in a land that doesn't have a frost line so what do I know..
That brings back memories. I used to fly into DuBois from Pittsburgh when I worked in the coal mines around Clarion - that was 40 years ago...!!
If vibration cracked the floor it would have cracked the footing on a mono it did not do it by having eather cause it would have picked the corner of the building up as well and it would be obvious If the crack is less than 4 feet I bet it could be patched by demoing that little area Bonding some rebar and repour it The demo would prove weather it's a lack of rebar it just interesting cause the corner of a mono footing is a pretty weak point to cracking cause all the bar is bent there to begin with As for running a plate tamp if your running in 2 foot lifts it take less than 10 seconds to bring it into compaction most of the time I have personally run mine literally against 4 inch stem walls and not had a problem
Never known you played up here in the land of the strip coal
Part of what some would say was my mis-spent yoof...!! For 18 months I shuttled between Jasper AL & Clarion PA It was all downhill after that.
It would be awful interesting to sit down and listen to you about all your travels I would have to say
Ahh Jasper, AL about 1 HR north of me on I-22. I bet you were with Drummond.
Whenever we see cracked floors inside a building and the footer is good.... the usual culprit is BAD compaction/inappropriate fill under the slab.... and we see it a lot near the edges... mainly because people didn't/couldn't compact close enough to the footing....
Sorry for the thread hijack but you know that Drummond are also in Colombia..? Walker & Winston counties were dry in those days. You had to go down Hwy78 to the Green Top on the Jefferson County line to get beer. According to the Costeños from the Atlantico Province in Colombia where the Drummond mines are located there are two type of gringos - "Gringos" and "Alabama Gringos"
Id go with poor compaction and skimpy rebar, the crack was there waiting to be exposed. Demo and patch would prove the weakness, but epoxy injection would be the quick fix to that crack. It just would nt reveal the cause of the crack. In years of doing pile driving jobs there were a few complaints especially if we were in clay. Got the point where my insurance co wanted a pre blast survey as they called it. Never created any real damage ,people just like to bitch. Bear in mind these werent big piles,maybe up to 20000 ft lbs energy, but you can feel it.
Small world isn't it! I wasn't around 40 years ago though. I grew up riding my dirt bike in the strip jobs around the Jefferson and Clearfield counties. They have made the access into and out of the DuBois airport much better within the last 10 years. I swear Barney Fife runs the security at that airport though.
HA! Winston county is still dry...Walker is not. Winston County stills calls itself the Free State of Winston. During the civil war they never picked a side - story has it they were selling moonshine to the North and South and didn't want to upset their customer base. A friend of mine from High School works for Drummond and regularly goes to Columbia. The pics of their mines down there are impressive.
So, what is the complainant wanting from you. Is the crack tight, or did the piece separate slightly ? Did you put a level on it to determine if the triangular piece heaved any ? A core drill sample containing both sides of the crack would be interesting to see if the crack is fresh.
Considering the vibration caused by them, it doesn't surprise me someone who's foundation is 2' away from where one was working is complaining. I have been 100' away from one on a 200 hoe and you can still feel the ground shaking. I personally wouldn't be running one within 20' of any foundation without someone signing off on all liability to any foundation damage caused. It's not always whether you caused damage, it's whether or not someone will try and come after you claiming you did. I bet on 20% of demos I do I get a neighbor complaining dropping pieces of concrete to break them was shaking their house and thinking it caused damage even if the house is 20-30' away. A basement floor cracking in a corner like a triangle is nothing new. But really hard to prove either way when it happened.