Engineer wanted splice on middle post 9

[hgcdesign]

hello guys , this may be a dumb question but I'm going to ask anyway. The engineer of record on a house I'm building wanted a steel beam spliced on middle post with a concrete pad of 24x24" . I built it with a 34x34 concrete pad and just left the post solid because it came that way and seames to make more sense not to cut it , I still supported it on the middle post . Now he is telling me I have to redo it because the pad needed to be 36x36 for a solid beam . This makes zero sense to me but I guess I could be missing something. Beam is 50' Thanks

 

[oldestguy]

Wait for a structural engineer here to provide two moment diagrams, one for each case along with the loads imposed on post and at ends. It does appear your footing is close enough to take care of the 36" sq. called for anyhow. Describe ground conditions: hard, medium, or soft?

 

[r13]

The EOR designed the beam as two spans simply supported beam. By not proving splice, you have made the beam continuous over the post. The reactions on the column base could be much different for the two cases.

 

[hgcdesign]

The ground is medium, There is 1 foot of compacted road base under the basement slab and concrete support pad.

 

[oldestguy]

Sounds like you are fine as is, but compare the cost of making the cut and splice as compared to another engineer giving an OK to what you did. Maybe "getting along" might over rule costs.

 

[r13]

I don't think you have any chance to argue with the EOR, as he is the one understand the system, wand who is fully responsible for the success of the project. If the pad hasn't been poured, you might just do what was been told. If it is already in place, try to point out that any corrective action may hurting the footing rather than help. I think he will be able and willing to find a way out of this situation. Be factual and calm when negotiate with the EOR.

 

[hgcdesign]

Thanks guys if I could actually get the EOR I think I would be fine, he's a real good guy, but he always send a student out there who has a chip on his shoulder trying to prove how smart he is and gives is a hard time for being 1/8th long on rebar.. We will just cut and splice it no big deal just trying to save the client money.

 

[r13]

Sounds like my first year on field assignment ...

 

[Tomfh]

Changing to continuous span will increase the post load somewhat, however I am a bit confused why 34 x 34 isn’t enough when 24 x 24 was ok. That’s a big increase in footing size, more than what I would expect is required to offset the extra load due to making the beam continuous

What are the span lengths each side of the post?

 

[oldinspector]

You say the engineer is reasonable and the intern may not be. Verify directly with the engineer.

 

[hgcdesign]

25' each side , other side is on exterior foundation wall

 

[Tomfh]

If the spans are equal I don’t understand why the footing isn’t adequate if as you say you have already doubled its size.

 

[JAE]

It may be that this engineer is assuming that a continuous beam over the column is equivalent to an equivalent beam/column joint and thus the column has moment imparted to it and, as another stretch, assumes that the base of the column, in bending, is imparting moment on the footing.

A theory as to how the EOR and his Robin are looking at this. Not that I agree with it. Just a guess.

 

[JLNJ]

The max difference is 5/8 / 1/2 or 12.5 percent if continuous.

The difference between 36^2 and 24^2 is 225 percent! Even a 34x34 is 200 percent.

I think the EOR needs to sharpen his pencil just a little and this will be fine.

 

[r13]

For an interior column with two 25' continuous span, I don't think 3' square feet footing is overly excessive. Also, we don't know what else is coming into this column, or beams. We all second guess here.

 

[canwesteng]

Could also just be a PFO from the engineer to a contractor that can't follow simple plans.

 

[Tomfh]

True, we don’t really know what’s going on. There may be a good reason that we’d all immediately agree with. At face value it does appear a little odd though.

 

[hgcdesign]

I apologize i left out a pretty important fact we have 2 other post also at 12.5' on each side.

 

[hgcdesign]

Also I have 6 major projects going on 2 with major steel work and haven't had 1 issue with any of the engineers, actually they have said they enjoy coming to our jobs because they don't have to worry about stupidity . This is our second job with this engineering firm and it will be our last . I can follow simple plans but if something doesn't make sense and it cost more I will always try and save my clients money and save time , we tend to way over build everything requested of us , because our name is on it. Just like the tjis on this job were 9.75 and we switched to 11.75 at a cost out of our own profit .

 

[radiocontrolhead]

Am I the only one here who is completely confused with this thread. Can we start all over, particularly at post 1? With diagrams/sketches and a very well thought out problem statement.