Concrete form deck too short 3

[RattlinBog]

I feel a bit ridiculous asking this, but I could use a sanity check.

Has anyone dealt with a situation where concrete form deck (non-composite) was ordered too short and one of the ends won't be able to bear on a support? Beams are 7 ft OC, but 13 ft form deck was ordered. I can provide a sketch in the morning when I'm back at my desk.

Would it ever be acceptable to arrange the form deck in a way that the end of one deck laps the end of the next deck between supports (in mid-air)? The lap joint would need to be connected together. I've crunched some deck bending stress numbers already but wanted to see if anyone has even come across something like this before... (P.S. Slab is designed to be self-supporting. Form deck is for construction only. Area is constantly wet, so I expect the decking to rot away over time.)

 

[RattlinBog]

Thank you. I'm definitely relieved. I learned a lot this week, what to do and what not to do. I'll reach out to Vulcraft technical folks next week and see if I can learn some more. For future projects, I'll plan to have a better handle on submittals and have an understanding of what's being ordered. I work in mining, and sometimes it's a bit like the wild wild west out here, especially on shutdowns.

I really appreciate everyone's help and critique.

 

[KootK]

@SRE & RB: you both did an exemplary job of crisis management on this. Level heads and fast decisions. I don't think that I've ever seen this forum put to such impressive, practical use

 

[RattlinBog]

I have some follow up questions/discussion points now that I've gotten some sleep and time to think. Let me know if I should start a new thread. This is a bit lengthy, but I'm trying to not lose sight of or underestimate the risks that were looming over my project last week. Sure, I could choose to wipe my brow and move on, thinking this won't happen again. But who am I kidding? I'd rather dig into this and feel some pain so hopefully I can learn something. Please don't hold back on criticism--that's where real growth happens. (Don't worry, I'll plan to have a similar conversation with a local mentor or two and not just be confined to this forum.)

I'm trying to be blunt with myself. It's becoming clear to me that I don't have a good grasp on where to draw the lines on construction means and methods / taking responsibility of certain temporary form work or shoring on projects where I am the owner and designer. I'll throw in some background below. My main question is this: what are some professional, safe, and ethical ways to handle means and methods/construction-related responsibilities before and during a project--particularly ones that are designed in-house by owner engineers? I'm beginning to open my eyes on just how ignorant I am related to this.

SRE, I don't know your full background, but I can relate to your owner role that you've described here and in other threads (I understand you also worked for a bridge contractor). You mentioned in-house design projects. That is also what I do in my role, along with other responsibilities. I complete the design of small to medium sized structural projects that I feel I can ethically take on given my past experience and skillset. For large projects or those outside my ability, I hire consulting firms. I worked in consulting out of college for just shy of four years. Unfortunately, my last year and a half was during covid lockdowns, and all our offices were forced to work from home for that duration. That was not a fun time for me career wise (not trying to make light of other people's hardships). It was challenging to talk to or be mentored by senior engineers, complete site visits, interact with owners, etc. My growth felt stunted, and I was frustrated. I ended up going back for my M.S. Civil Engineering part time and jumped ship to work on the owner side at a local mining company (in the processing facility, not the actual ore body). I really enjoy this type of work, but it also shines a light on my weak areas.

The last thing I want to happen is for someone to get injured, or worse. How do owner engineers manage that risk? Do they outsource all engineering to consulting firms, doing no in-house designs themselves? Do you place all construction-related activity and shoring/rigging/falsework responsibility on the contractor? Do they complete in-house design of the permanent structure but hire a firm to design shoring/falsework, etc? What happens if the contractor is a smaller, local outfit that does good work but perhaps doesn't have the resources to complete their own construction-related design? Are they supposed to automatically know to hire a consulting firm/third party to design or review their shoring needs? What if they don't take this step but then something unexpected happens during construction (surprise, surprise)? Who takes on that responsibility amid the rush and chaos? That's a lot of questions, some rhetorical, but hopefully you can see where I'm coming from.

 

[phamENG]

RB - I worked in a similar role, but only briefly. I went into it just before Covid hit, and 6 months later I was 'working from home'. Not a lot for an 'on site' engineer to do 'from home'. I decided to leave and start my own design/consulting business. So my experience is not in depth, but I have a few thoughts.

-In house vs. out-sourced: your approach is similar to what was expected of me. Small projects I did (foundation for a little MBS enclosure, repairs to a damaged building, new access stair, etc.), the big mill expansions we hired out.

-Means and methods: this can be tough. It's best handled through detailed and enforced specifications. Know what your specifying, why you're specifying it, and when you need to hear from them to confirm they understand and will meet it. In an industrial setting like this, as you know, time is more valuable than money. The contractor has insurance, sure, but if your facility is anything like the mill where I used to work, extending a shutdown by 2 days would exhaust the insurance and bankrupt every contractor on site. So there is no meaningful way of recouping those losses. That means there is some amount of shared responsibility to get the plant back up and running, even if the contractor or 3rd party engineer made a mistake. The level to which you wade into that is based on your ability first and comfort level second. (Hopefully you're only comfortable when you're able...)

 

[RattlinBog]

phamENG, your description on means and methods is more or less exactly what I'm faced with. Extending a shutdown is typically out of the question. You complete a design, plan and schedule, award a bid, and then something unexpected comes up in the middle of construction at 8 pm on a Tuesday. You're firing up the line on Friday. Okay Mr. Contractor, this is your mess so clean it up. Well we can't. The material we ordered took 6 weeks to show up; you won't get anything new in time. Now what?

 

[phamENG]

That's why submittal requirements are so important. Make them provide shop drawings. Have some sort of pre-demo meeting that involves verification of all materials. You can't account for everything that might come up, but you can be sure that they have everything they need to do the intended project.

It's different from a 'regular' construction project. On a regular job, a delay of a week or two isn't good but can be dealt with. In your case, it's not an option. So you have to take extraordinary measures to ensure it doesn't come to that. Better to put the burden of proof on the contractor before than for you to deal with the pressure afterwards.

 

[SlideRuleEra]

RB - The definition of some of a Contractor's means and methods (M&M) is often straight forward:
If the Contractor keeps materials, it's part of his M&M. On this project the steel decking remains even though it is used only for forms. That is not M&M. Selection and design of this deck is the Owner's responsibility (more on this on a followup post). If the Contractor had used, say, additional temporary supports as part of the form support, that is M&M.

How the Contractor performs the work is part of M&M. He could pump concrete or use a crew of workers to wheelbarrow concrete into place. (Just an extreme example, the most efficient choice is pretty obvious... but not always.)

Concerning design of the Contractor's M&M:
Always have a prebid meeting, with all bidders present, to go over any factors about the project that the Owner needs for bidders to know.
Always have a preconstruction meeting to discuss with the selected Contractor what he plans to do.
If you want to be certain that a Contractor knows what they are doing, in your spec require submittal of detailed M&M for your review and acceptance before work begins. (NOTE: Acceptance, not approval).

If the project is especially challenging, require that the M&M submittal be signed & sealed by a PE.

If I think of something else, will post again.

My background:
BS in Engineering (Energy Conversion), took the EIT Exam and passed, my senior year.

Never worked for an engineering firm.

Through ROTC in college, six weeks after graduation I'm a 22 year old active duty U.S. Air Force second lieutenant assigned as a "Development Engineer" (as in Research & Development) for aircraft life support equipment at Wright Patterson AFB, "Area B" (formerly known as "Wright Field"), Ohio. Served four years active duty; all of this time counts with my state engineering board toward the four years experience needed to take the 8 hour written PE exam... take it and pass.

Complete active duty and, with my father, formed a highway bridge construction corporation. I ran it as Chief Operating Officer for 6 years. During this time decided to make a DIY transition from mechanical/electrical engineering to civil/structural/geotechnical engineering. Corporation is marginally profitable, so performed an orderly shutdown of the company. Note: We did all our own work, such as pile driving, form / pour concrete, etc. (no subcontractors).

Took job with midsize electric utility (generation - 17 major generating units located at 4 different geographic sites, with smaller units at other locations) as the only civil/structural/geotechnical engineer in that department. Note: Company knew full well that my degree was in ME/EE, in fact, that was a job requirement. Over time, promoted to corporate level Principal Engineer (Civil/Structural/Geotechnical) for the company. Together with my very talented understudy (19 years younger than me), we took on the most difficult technical projects anywhere in the company. Note: You remind me a lot of the understudy. Retired after 21 years.

In the mean time, I remained in the active Air Force Reserve (as an engineer) for 18 more years, retiring with total active plus reserve time of 22 years.

Formed one person LLC to practice engineering for nine years, more as a profitable hobby than a job. Some design work to help homeowners & businesses get out of building code problems, but also teach PE review course, construction management, and technical editing for Professional Publications, Inc. (PPI) books to prepare engineers for the civil / structural PE exam.

Then retired for real. However, six months ago, the Homeowner's Association where my wife and I live asked me to join the Board of Directors (pro bono, of course) to use engineering skills to start resolving the aging infrastructure problems (roads & streets, surface & subsurface storm water drainage, pedestrian bridge rebuild / replacement, etc.) Unretired my PE license and in the thick of things on those projects.

 

[JStructsteel]

Long post, but just have them shore at that location.

 

[RattlinBog]

SRE - nice to read about your impressive career. Thank you for your service. Thanks for the advice/feedback on M&M, etc. I'll put those into action. We already do pre-bid and pre-construction meetings, but there's usually a heavier focus on safety than anything.

I wish I had someone like you for a boss that I could learn from daily. I'm the only structural at my plant. Somedays I miss consulting just to have that daily/weekly mentorship back, but I do enjoy my new role a lot, frankly more than consulting. I would also have to take a big pay cut. At least I have old colleagues and other mentors that are usually a phone call away. Going back for my M.S. has also helped me feel better about technical competence. Right now I'm studying to get a better understanding of LFRS and diaphragm design. I'm decently competent with individual structural member design; putting it all together in a building system is another animal.

 

[SlideRuleEra]

RB - Like KootK, I thought you did an outstanding job of handling this project starting when the 13' long deck was delivered. I do have some constructive criticism for you to consider on the Owner in-house design process used. May be a few days before I can get back to you. This morning we had to move out of our house to allow a Contractor to replace flooring destroyed by a broken potable water pipe. That post I made yesterday is not one of my better ones, didn't accurately address your questions, sorry.

 

[RattlinBog]

Sorry to hear about your house situation. Doesn't sound fun at all. You've already helped me a lot. I don't have any expectations of you if you don't get to a follow up reply.