I am having trouble determining the proper unbraced length to use for a bottom running crane runway.
I am looking at basically two types: continuous runway with top flange hanger supports at 25ft oc, and 50ft runways (2 span continuous) with top flange hanger supports at 25ft.
Runways are...
I'm designing pile fdns for a large conveyor system (150'-175' high towers by others). Soil site class F, high seismic area. In reviewing ASCE 7, I am not sure if the towers need to be designed with dynamic modeling, or can ELF be used? The period is less than 3.5Ts, but given that the towers...
Design of a ringwall tank foundation, (ringwall required by owner).
I have proportioned and designed the fdn so the soil pressure under the fdn is the same as the soil pressure under the tank (at the same depth as b/fdn), which I think is pretty standard practice to attempt to limit...
In reviewing ACI ch 21.2.5, it seems unless a615 bars meet certain criteria we should be using a706 bars in concrete for moment frames and wall boundry elements.
This is used, I think, because the a706 bars are more ductile. Is there a similar criteria for masonry? I cant seem to find it if...
I am designing a pile foundation to support a car shredder mill. The manufacturer gave dynamic forces and frequencies on the drawings, so I have performed a time history/dynamic analysis in staad to get the foundation natural frequencies and vibration response.
The natural frequency of the...
I need to supply an axle load rating for a 40 year old concrete tunnel roof. I am looking for guidelines for determining effective widths (one way bending assumed) for point loads and wheel loads for an elevated concrete slab. I don't think the AASHTO code equation (4+.06s) really applies...
Does the new staad 2006 release code check against the new 13th edition AISC code? All I can find on thier website is that it designs to ASD and LRFD which could be the 9th and 3rd editions and not the 13th, not sure?
Preferably it would allow a code check to all three for those of us that...
I am working on an existing structure with some single angle columns, built in 1955, and am working to make it meet the 2003 IBC code requirements. I am aware of the method used in the 1989 ASD specification and the article from 1991 AISC Engineering Journal showing how to calculate the...
Has anyone else had problems with Staad 2001 not running in the last couple months? When I try to run a model I get a "Cannot Open Input File for STAAD Run" message and the program wont run. We have three "dongles" in our office and most of our computers won't run the program most of the time...
Hi! This is my first time on this forum. I'm a new structural engineer, 1 yr experience. I hope I can contribute something to this site, but for my first post I have a question...
I work in a multi-dicipline Industrial Manufacturing firm. Until this Jan we have been using the 1997 UBC...
