I am working incorporating the design and detailing requirements of a Special Reinforced Masonry Shear Wall (R=5) for a seismic design category D structure. My only option is to use a SRMSW and cannot use intermediate to relieve the detailing requirements.
I am reading ACI 530-13 7.3.2.6 d...
Attached is a concept for a lateral force system being proposed for seismic design category D. The structure is being categorized an eccentric braced frame. My concern in the portion of the canopy column cantilevered and its possible violation of SDC D structures and proper R-value assignment...
Attached is a picture of what I believe is efflorescence build up on the exterior wall of a tunnel. It builds up to almost a 2" thickness (iv never saw eff. build up like this, hints the "I believe" clause). I believe it is a concern based on what I have read to this point as it can be harmful...
I have 260'x290' building consisting of 3 different lateral systems. Precast composite sandwich panels, masonry shear walls, & brace frames. Diaphragms are all flexible so am not to worried regarding one system attracting a majority of the load. Area is hardly no seismic so wind load is sure to...
I have a pre-engineered metal building that I am doing construction management on. The question was raised why the building was not insulated to prevent condensation. It is my understanding/belief that if the area is not heated or cooled the temperature difference between the interior and...
I have a grade beam that is spanning between to drilled piers acting as a torsional member for a roughly 5' high retaining wall. The ideal layout with grades puts the grade beam at roughly a 20 degree angle.
I have some flexibility as I can lower the upper driller pier to reduce the angle. I...
I have a scenario where I am using 6x4x1/2 angle as a deck support anchored to a CMU. I was think an expansion anchor would be best suited for this application. The angle/wall is not heavily loaded supporting 100 PLF.
Attached is my concern,there are certain areas that the anchor is not...
I am looking into the uplift capacity for a 3'' 20 gauge metal roof deck with supports at 14'-0'' OC. In zone 3 of my components and cladding wind load with and effective area of 50 SF (I am considering a 3' wide sheet 14' long) I am getting an uplift of 92 PSF. If I put that into a an ASD load...
I have some pretty healthy tube sections (20x8x1/2) for a canopy roof. The architects desire to make the roof curved. Are there any references out there that recommended the tightest radius that the tubes can be rolled too. I am assuming they roll them in a similar way they camber a beam and...
I am using staad pro to evaluate a moment frame system. I am using the steel code check and I am getting an overstressed ratio on my frame beams that I know is not correct. Since the beam is see a negative bending moment it is taking the beams capacity as fully unbraced.
Is there a way in...
I know there are a ton of threads about fixed vs pinned base. I am using a pretty standard fixed base detail (see attached) but am struggling to follow the load path within the connection.
I assume its a sort of belt and suspenders type connection between the shear and bending action of the...
AISC 13th edition table 4-4 uses 0.9 for safety factor in compression. Table 4-15 uses 0.75 for safety factor in compression. Does anybody know the reasoning behind this?
I have a 4 x 4 x 1/2 column that is real close to capacity, my thought was if I filled it with concrete it would give me...
I have some very long (approximately 80' with no perpendicular walls framing in to support) 2 story corridor walls. The floor to floor height is 16'-0'' for the 2nd floor and roof. The second floor will have a composite slab spanning over steel beam that frame into the cmu wall, and metal deck...
I have a long span wall (53.5 ft from column support to column support). It is support as varying brick veneer from 9' on the high side and ' on the low side. This is the only load that beam will be carrying. With limiting the deflection to 0.3'' the beam is huge as you can imagine (W36x182)...
I am designing a column with a fixed base. Service moment is in the 540 k-ft range. The baseplate thickness is getting to be very large in the order of 3 1/2''. I am considering adding stiffners to increase the section modulus of the base plate.
As far as sizing the weld and considering the...
I am questioning the logic behing ASCE 12.12.3 structural serperation. If two seperate building are to be seperated, why is this distance not the algabraic sum? To me is does not make sense to SRsS (Square Root Sum of Squares) for inelastic displacements.
Regards,
I have a curiosity question as to why the diaphragm forces Fpx from ASCE7-05 12.10.1.1 can produce in the magnitude of four times the seismic design force produced by Cvx vertical distribution. Why should the diaphragm be designed to such a large force if the lateral system cannot take it...
i was doing some research and found a artile stating that vibration design criteria only needed to be checked for idealized framing layout. This is a far different approach then what i have taken in previous projects where vibration designs were heavily dependent on deflection. I wanted to get...
I am trying to develop a better understanding of structural system specifically steel vs concrete. The best way I could think of doing this listing some of the controlling factors and trying to decide which one is better than the other. I realize there are some factors that are based on...
