Anvil Stand question

[JHCC]

8 minutes ago, Frosty said:

Where on Earth does anybody drive concrete piles?

Louisiana. The piles that support the Lake Pontchartrain Causeway are 54" diameter tubes of prestressed concrete. See https://www.asce.org/project/lake-pontchartrain-causeway-bridge/.

[Beavers]

In Nebraska

In the late 90's I did the surveying for a DOT bridge with with driven concrete piles for the abutments and piers. I haven't seen them used since then, but they are still covered in our spec book. 

[Frosty]

Interesting, those are displacement piles that rely on skin friction to keep them from displacing laterally, tipping over. Cast in place concrete is prestressed as well, it doesn't require a factory or special facilities, hydraulic cable or rebar pullers are typical. 

I'll have to see if the drill logs are available online but from reading this article I'd have to say there wan't much resistance to advancing the piles. They set them two at a time and connected. Here we used a vibratory "hammer" to advance piles and the as built call the piles driven. 

I'll tentatively cop to "hammered" concrete piles but I'll want to look deeper. 

Thanks for the link John.

Frosty The Lucky.

[Beavers]

Standard Specifications for Highway Construction

Page 437 is the start of the pile section.

 

[Ted Ewert]

42 minutes ago, Frosty said:

I know this is fun your you Ted but there are people reading this forum who don't realize you're brainstorming ideas and we have to address your misconceptions to keep others from making those mistakes. 

I suggest you do your homework before accusing me of misconceptions. Google is a good place to start.

[JHCC]

29 minutes ago, Frosty said:

I'll tentatively cop to "hammered" concrete piles but I'll want to look deeper. 

Also, to "drive a pile" could presumably be understood in the non-literal sense of simply "installing a pile".

[Ted Ewert]

3 minutes ago, JHCC said:

Also, to "drive a pile" could presumably be understood in the non-literal sense of simply "installing a pile".

See above photo. That's a pile driver in the background and those are concrete pilings. I've actually seen this done.

[Beavers]

The concrete piles that I saw were just like the picture Ted posted. They were hammered into the ground just like steel H piles with a big diesel powered hammer. 

[Frosty]

Boy was I wrong, my apologies Ted. I've been reading the ASCE rules for driving concrete piles and am about half way through a Txdot, pile foundation, webinar. 

I can see why concrete piles aren't use here and probably why the bridge engineers I used to associate with never talked about them. 

Research first talk later and I don't know how many times I've said that very thing.

Pick your crow recipe Ted, I'll eat it.

The main topic for hammer driven piles is how to prevent impact damage to the concrete, lots of cushioning and heavy slow ram weights.

Frosty The Lucky.

[scotts_magic]

I have also witnessed it being done but don't recall much in any sort of rebound from the power hammer equipment being used on concrete pillars. Seems like concrete would absorb any rebound you might want to get with your anvil just to save your joints and make moving metal more efficient.

[ThomasPowers]

I'd say that at least on the outside most of planet Earth is "splashy"... meaning of course that on the surface Oceanography is more an "Earth Science" than Geology---(I became interested in Geology by knowing a Selenologist... back in the mid 1960's.)

The issue with anecdotal evidence is that what may hold true in a specific case for a specific person;  may be different for people working elsewhere/elsehow.   Big difference emplacing piles in gumbo than in Glacial tills.  (When I was studying drilling there was an example of hitting an over pressure zone in LA abd a picture of a piece of drill stem sticking out of the mud about 4-5'  with around 85' buried. It had been pushed out of the hole fast enough that it buried itself coming down.  Meanwhile in Oklahoma I worked a job where 3' a day was a good days accomplishment.)

[Ted Ewert]

I don't want you to eat crow Frosty, I would rather we just had a more constructive dialog. I'll be the first to admit that I spend a lot of time out in left field, but I'm not trying to mislead anyone. 

Ted

[Frosty]

11 minutes ago, Ted Ewert said:

I'm not trying to mislead anyone. 

I now you're not. Unfortunately we can get lost in a topic and folks who aren't up to speed may take it wrong. Heck I made a living engaged in foundations geology and got it wrong. Provincialism on my part, I spouted off based on regional knowledge. I deserve a good dose of crow. Go ahead make me catch and cook my own, I deserve no less.

You might like to read up a little on the failure conditions for driving piles. Direct contact between the pile "cap" or "Helmet" and the pile is an automatic failure condition. The two reports I've read say a minimum two layers of 3" plywood are a must. One layer between the cap and pile and another between strike plate and "cap" or "Helmet".

Interestingly enough too long piles in too soft material lead to compression wave rebound either pulling the concrete pile apart or meeting the next impact wave traveling down the pile causing crushing damage. It's really interesting reading. 

Frosty The Lucky.

[Ted Ewert]

We can speculate endlessly on this topic, and it is interesting, but there's nothing like putting it to the test. I'll build a concrete stand and see how well my theories hold up. If it falls apart, I'll be hunting some crow myself. 

[JHCC]

43 minutes ago, Ted Ewert said:

See above photo. That's a pile driver in the background and those are concrete pilings. I've actually seen this done.

Oh, I have no doubt about it; see the link I posted about the Lake Pontchartrain Causeway. I'm just saying (speaking as someone whose training is in language rather than engineering) that "drive a pile" might be used in a non-technical, informal sense as well as the technical "drive it into the ground by hitting it" sense. No worries.

[Buzzkill]

If your past work that I've seen here is any indication, I have no doubt that you'll come up with something that works well for you.

I'm also a steel tripod guy.  I don't have a permanent forging area (yet) so I have to set up each time I forge.  The steel tripod is fairly light, it's stable, and I can fairly easily use a modified dolly to wheel the stand and anvil where I need to go.  If I didn't have to move it a lot I might want something with more mass or something bolted down, but unless I'm using a hammer around 4 pounds or heavier it stays put well either on a concrete slab or in dirt.

[Marc1]

4 hours ago, ThomasPowers said:

There are a number of diagrams put out by the manufacturers of huge power hammers historically showing them being set on layers of large oak balks before they set on concrete,

 I have personally installed back up generators for large factories, who's steel base was bolted to a concrete block and the concrete block sat in a deep pit on 150mm of cork. If we did not do this, the anchoring bolts would break loose in a short time. 

[Ted Ewert]

Thanks for the vote of confidence Buzzkill. I went out and bought the materials today, so I should have something put together in the near future. I'll start another thread when I get it going.

[MC Hammer]

Ted, I think you will invest a lot of money and time in building this concrete anvil stand only to have to go searching for a stump in the near future.  For hundreds of years blacksmiths used wooden stumps because they worked and were relatively cheap.  Don't over-think things.  Start simple with a stump and if that doesn't work build something else.  

There are plenty of posts here talking about cracks in their garage floors from power hammers on concrete.  You can put a lot of rebar in your anvil stand and you'll just eventually crack and chip away the concrete down to the top rebar pieces.  You are trying to "build the better mouse trap" when you could use the "mouse trap" that works and has worked for a looooooong time.  I am impressed with your out of the box thinking, but some things just work..........like wooden stumps and metal anvil stands.  Tons of them in use.  Your 200 lb anvil is not a monster and I'm sure there are some on this forum that have a 200 lb anvil mounted to a stump or metal stand.  My anvil is 179 lbs and it sits perfectly on a wooden stump secured with Z clips and lag bolts.  It doesn't move and in the end, I can modify it however I want.  Please don't read any emotion into this email, I'm just not understanding why you'd want to go through all that engineering to build a concrete anvil stand when it's much easier to use tried and true stands that have been working well and performing well for generations. 

[Ted Ewert]

MC... I'm just doing this as an experiment, and I'm using my little 70 lb anvil as the guinea pig. I'm only wasting $50.00 if it doesn't work, and I'm having fun designing and building it. If it works I'll build another one for the bigger anvil. BTW, the anvil will be mounted on a plate, which will be connected directly to rebar extending to another plate bolted to the floor. Steel will be baring most of the load and shock while the concrete will add mass and stiffness. Stay tuned...