I have been asked to design some foundations and buildings for an industrial project with an expected 10-year life. Is it possible to do anything differently for this shorter life project than it would be for a standard expected life design that would reduce the construction costs? Other than...
I am writing a grouting spec for baseplates and have been reading the resources I can find to do so. In everything I have read, it says that when grouting in cold weather, you need to heat the area, foundation, etc. before and after grouting to allow it to cure properly. Then the resources I...
I have found myself trying to get some post-installed anchors to resist uplift in existing foundation stem walls many times over the years and it is always hard to do. The numbers from ACI 318 App. D just don't work out to where you can resist more than 2500 or 3000 lbs in tension or shear...
In the plant where I work we have large vehicles that move heavy vats of product around. The vehicles have hard solid tires. The pair of wheels in the front are located together in the center of the machine and rotate to do all the steering and drive the machine. But the front wheels rotate...
What formula or method would you use to determine the force required to push the sharpened tip of a round shaft a certain distance into a very thick piece of metal (magnesium in my case, but I assume the formula would be the same using the proper E or Fy or something for whatever material)? To...
I have some foundation settlement problems under some smallish lightly loaded spot footings and under some very large heavily loaded mat foundations. The settlement in both cases seems to be mainly caused by acidic runoff seeping through the soil and dissolving the underlying soils (and...
If the numbers work out, would you ever use a shear connection to support a cantilever beam? In other words, would you be comfortable using something like a single angle three bolt shear type connection to support the "fixed" end of a cantilever steel beam if it is lightly loaded and the...
We are in the middle of a project where there are large concrete column bases with large grout pockets for shear keys. Due to unforeseen circumstances we have to shut down construction until next spring. Our winters usually are cold and snowy mingled with temperatures that rise above freezing...
I think this is a simple question, just want to get an opinion because I haven't run across this before. I have a concrete moment frame that supports a small elevated platform and it is in earthquake country where Chapter 21 of ACI applies (special reinforced concrete moment frame). Chapter...
I am a PE and do concrete design frequently. I also frequently am involved in watching the designed concrete members get built in the field and I am constantly stressed and depressed and aghast at the inattention to detail that the concrete contractors seem to have. It seems they never pay any...
I want to weld two steel channels back to back to hold them together for gravity loading. I don't think there is really a strength requirement but I want to keep them together. I was thinking of using a stitch weld (say 3-6) along the seam at top and bottom, but I am not sure what type of weld...
I am creating a spreadsheet to design baseplates based on AISC DG1. It all seems pretty straight forward except for two things. The first is I can't conceptually understand why the thickness of a baseplate with large moments would be governed by the n dimension of the baseplate on the...
I am involved in a project that has a concrete contractor and a steel erector as two separate contracts. Neither contract specifies who is to provide leveling nuts or shims. In my mind the answer is obvious that the steel erector is to provide the leveling nuts or shims because they have a...
Does anyone use Visual Analysis by IES for structural analysis? I used it 6 or 7 years ago and liked it pretty well, but am wondering if anyone has used it recently that can comment on ease of use, reliability, etc. Thanks.
I work at a plant where we have a round wood stave tank, 55' diameter, that has settled about 12" on one side, putting a bit of a tilt to the tank. I am wondering how I figure out at what point this becomes a safety issue. How do I determine what angle the tank can be sitting at without the...
I am trying to figure out how to attach a 42" pony wall around the edge of an elevated floor and connect it to the floor in a way that it meets the 200 lb point load requirement in the IBC on guardrails. If I use 200 lb applied at 42" height, I get a moment at the base of 8400 in-lb. Using a...
I am reading through the ACI 530-11 masonry code and don't understand how the reinforcement shear stress is calculated. The formula is Fvs = 0.5(Av*Fs*d/(An*s)). I am looking at this specifically for a shear wall, not a beam, but I think the formula is the same for both.
Av is defined as the...
I am designing a house that is wood framed and has brick facing from ground to roof all the way around. In determining what holdowns are required from lateral loads, I am hesitant to include the weight of the brick veneer as a resisting weight for overturning resistance because I don't know...
I have heard a few building officials say that all wood members (beams, joists) must be bearing on at least 1.5" at the support. I cannot find this is the code and wondered if anyone else knows where it comes from. I think it is probably good practice in most cases to have the beam or joist...
I have always thought that the thermal factor Ct for determining roof snow loads should be taken as 1.1 for most homes. From what I understand Ct=1.1 when the roof is ventilated and the insulation between the roof surface and the heated area is greater than R=25. I live in Utah and the roofs...
