Thanks to everyone for their responses. We aren't designing the actual cranes...just the building in which the cranes operate. The crane manufacturer is not selected yet. I expressed my concerns to my boss and the project manager and we all think we should get the other office involved. I just...
I work for a large engineering firm. I've been there for about 5 years. I am licensed and normally work on warehouse type structures. I'm in my early 30's. I was recently asked to get licensed in another state for an upcoming project. I agreed not knowing much about the project. We are...
I am working on the design of a steel manufacturing building in mobile, alabama. It's on the coast. One statement that I came across is, "The current site is located in a Zone VE (elev 12), which is a Coastal Flood with Velocity Hazard (wave action) with a base flood elevation determined."...
I have a pump room with a ceiling framed of light gage metal studs and 2 layers of gyp board on the bottom. The mechanical guys are running a 6" pipe below the ceiling. The ceiling is a one hour rated assembly. Can I use a self tapping screw in this situation through the gyp board and into...
Is there a limitation on the spacing of the vertical reinforcing around the perimeter of a round concrete column. With round ties, is it to be limited to 6" per ACI 318? Or do round ties let me go further than 6"?
I am looking a set of structural drawings from 1918. The concrete mix is called out as 1:1:2 and 1:2:4. Does anybody know what this means? What would be the corresponding strengths of concrete?
I am designing a base plate of a special concentrically based frame. I understand that it is preferable to maintain a ductile failure mode. Does this just mean that the strength of the concrete embedment needs to be greater that the steel strength of the anchor bolts? Currently, I have 1 3/8"...
Ok, there are rows of joists parallel to the frame line, but they are not on the frame line. How would that work? Wouldn't the load ultimately have to get to the frame line? The rows of joists could collect the load and transfer the load to the joist girders. But then the joist girder would...
Thanks. I also have to look at the other direction, where the collector beam is parallel to the joists and the top flange is braced only by the metal deck. In this direction, I can't add an extension.
I have a steel framed building with braced frames. On the frame lines, I have wide flange girders supporting joists spaced at 6' o.c. The wide flange girders are acting as collectors and support an axial force. Looking at the weak axis of these wide flange collectors in compression, what...
Hi
AISC has two design procedures for ponding. One is for a case where there are flexible primary and secondary members. The other is for when there are flexible secondary members bearing on a wall (infinitely stiff primary member: Cp=0)
What happens if you have roof joists bearing on a...
AISC seismic C8.5 states, "column bases are required to be designed for the same axial forces as those required for the members and connections framing into them. If the connections of the systems are required to be designed for the amplified seismic loads or loads based on member strengths...
Hi,
I understand that the brace connections for an scbf need to be designed for the expected strength of the member. At the pier and foundation, the brace gusset plate is attached to the column and base plate. Does the base plate attachment to the pier and footing need to be designed to...
I am trying to calculate a required building separation per ASCE 7. For the special concentric braced frames, the deflection amplification factor is 5.0. For the building movement, I am adding the deflection of the braced frames plus the deflection of the diaphragm. The amplification factor...
I am designing a 70'-6" high by 16'-1" wide special concentrically braced frame in the state of washington. I went with a SCBF because of the height of the warehouse. The frame supports an earthquake force of 25.0kip at the top. The dead and live loads are small. I have two columns and I...
What's the correct way to determine the wind exposure category of a building? The building code seems vague (big surprise). Other engineers in my office usually just design the building for exposure B. But I don't see anyone going out to the building site with a tape measure and walking 2600'...
I am using ENERCALC to design some tilt walls. ENERCALC lets the engineer select the ACI 318-02 procedure. Under this analysis procedure, you can select a base fixity for the tilt panel. How do you determine the amount of fixity at the base of the panel? The program let's you select a fixity...
I am designing a building in a hurricane area. The wind speed is about 130mph. The building is a large warehouse with numerous dock doors. These dock doors make it partially enclosed. I get a component and cladding wind uplift of 51.3psf on the joists. Is this force reasonable? I was told...
