I have a project that was supposedly designed for a future 2nd story addition. Masonry bearing walls are used to support a precast roof (currently) with the intent to add a topping to the precast to make a floor and then we are to add new masonry walls and a new steel joist/deck roof. The...
Hello,
I have a condition where I have W8 outriggers bearing on top of a continuous HSS tube beam. The outriggers place a torque on the HSS tube. I want to make sure that I'm checking the wall of the HSS tube will be ok for the compression force created by the couple force. My thought is to...
Hello,
I recently watched the webinars from SJI discussing the use of Virtual Joists and Virtual Joist Girders in RISAFloor. They discuss after using the Virtual Joist in the software, to use typical call outs on plan. What I don't seem to grasp is how to turn the VJ callout in RISA into a...
I'm in the Midwest and we typically detail stoops with foundation walls that are extensions of the building foundation wall. I'm currently working on a project with 1000's of feet of storefront where a door could be inserted anywhere along the storefront. We are trying to figure out a way to...
Some beam web openings were cut larger than what I had called out on plan for a project. The beams are W12x14; pretty small. The current size violates the detailing and geometric requirements of the design guide so I need to "fix" the beam.
I’m looking for a little guidance on what to do:
1...
Hello,
I'm currently reviewing some calculations on a retaining wall. The engineer is checking Vu against (0.5 * Φ * Vc). They are basically using this to say that they don't need shear reinforcement. I always thought that this only applied to concrete beams. For walls and slabs, I just...
Hello,
I am checking my flexible diaphragm strength and deflection. I used ASCE 12.10.1.1 to get the design forces. I am using dynamic analysis so my dynamic force Fi, for each level is limited to 0.85Velf. Do I use this same force for the deflection? Can I reduce the force down to Vdym...
Hello,
I'd like to clarify a design issue we are having. We want to make sure we are applying the appropriate Cs value to our building mass.
We've run through the numbers and the basics. We are using ASCE 7-05.
Cs = 0.311 (12.8-2)
Csmax = 0.947 using just Ta = .156
Due to some...
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I'm evaluating an existing structure that has a 1-way slab supported by concrete beams and concrete walls. The existing documents indicate a Live Load for the room. I'm using the concrete beam reinforcement schedule to double check the beams for some new equipment in the room. I have...
I have a column with a large uplift and I'd like to use the D.5.2.9 part of appendix D. This lets us use the reinforcement in the pier to develop the tension. My issue is that D.5.2.3 has shortened my effective length for equations (D-4)- (D-11). Does this shortened effective length still...
Hello,
I'm supposed to do a small presentation to my department about how to use the Direct Analysis Method for Stability. I've downloaded some papers and articles from AISC, but I was curious if anyone knows of some good texts that explain it. As I haven't delved to deeply into myself, I'm...
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A construction issue has arisen that requires the top and bottom flange of a beam be coped out on 1 side, effectively leaving me with a channel. This cope would be required for 3 feet of a 20 foot span and would be in the first third of the beam. This beam is being used as a...
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A discussion has been started in my office about the use of plates in a model and their uses.
Usually, I'll model a plate between each beam. So, if I have a bay with 4 infill beams I have 5 plates. Typically, I check the plane stress box when I put these plates in so lateral...
Hello,
I'm a structural engineer and two electrical engineers showed me a detail of their generator pad that had a note that read something like, "...95% proctor test or 55psi PBV." Can anyone tell me what PBV means?
Hey guys,
Our company recently bought us iPads. I was hoping that some of my fellow engineers would know about some good apps that help out with work. I'm a structural engineer, but I'm really looking for any app (free or otherwise) that has been helpful in the engineering field. It...
Hello,
I'm diving deep into braced frame connection design. I'm trying to calculate my radius of gyration for a gusset plate. I know the d/sqrt(12) equation for rectangular members, I'm just not sure what to use for "d". Would it be my Whitmore length? would it be the actual length...
Hello,
I'm basically trying to model a strip footing that is about 80 feet long and 16 feet wide and 6 feet deep. I have 5 point loads from columns loads from a different model. I figured the best way to model my footing is to add nodes at 1 foot intervals and then add a compression only...
Hello,
I'm still pretty new at modeling things in RAM so I'm hoping that there is an easy solution to my issue. Does anyone know how to hang a column off of a beam in RAM?
Looking forward to the suggestions!
Alex
Hello,
I have a 2x6 load bearing wood stud wall that the contractor wants to put conduits through (1.25" - 1.5"). Most of the studs are actually under windows so I have quite a few full height triple king studs. I'm wondering what the max allowable hole through the load bearing studs is...
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I'm working on a wood truss project with numerous valley's as the ridges change direction freaquently. I've got the balanced and unbalanced loads for the simple peaked roofs, but what about the snow load in the valley? ASCE 7 doesn't cover this well (or at least as well as I can...
