Recent content by dlew

CWT, For a more detailed discussion of a spreader beam unsupported length see Thread 507-38270.

Hey Guys, Thanks for your fast response. Your comments and references were very useful and are appreciated.

Hello! I am working in the reinforcement of an existing steel structure to carry additional loads. We are planning to add reinforcing plates to those members that need them. The existing dead load stress in those members is approximately 15 to 20 ksi. Live load is relatively small. The...

pasachi, Pre-engineered steel trusses are designed by the fabricator. The designer specify on the drawings the critical dimensions and the loads. If you are only interested on the trusses, you could contact a joist girder fabricator. If they are interested in the job they would answer any...

PurdueEng, Figure 6-16 of ASCE 7-02 gives the GCp coefficients for Domed Roofs for all heights of buidings.

jheidt2543, I think the purpose of the rubber pad is to make the truss-to-column connection a simple connection, and avoid a moment in the column due to the gravity loads. I assume the stability of the building for lateral loads is provided by other structural elements.

auxblade, My experience designing with fiberglass elements, both hand-layon and structural extruded shapes, is limited to mechanical equipment as tanks, chimneys, etc. The degradation of the mechanical properties of the fiberglass with temperature and exposure to the environment need to be...

fritzee11, It is Irving Boberg's paper "Oil Tank Foundations", dated 1951! It only addresses gravity loads. I believe Boberg was the chief engineer of Chicago Bridge and Iron at that time. Regards AEF

CWT, Here is my two cents worth of thought. The 6" by 1/2" plates provide lateral support to each column about their weak axis from the crane girder down. The two columns are NOT braced about their strong axis by the plates. The critical buckling will be, then, about the...

haynewp, I agree with you that the provision of 20 psf for partitions should be included in addition to the 50 psf live load (per ASCE 7).

CTW, The ASCE 7 shows 4 subcategories for OFFICE BUILDINGS: File and Computer rooms Load based on equipment weight Lobbies and first floor corridors 100 psf Offices 50 psf Corridors above first floor 80 psf I would consider...

sc, In rigid base plates the tension in the anchor bolts is large, and that requires thick base plates and heavy welding of the column to the base plate. A type of base plate more appropiate for a rigid column base is shown on page 4-131 of the AISC's "Manual of Steel Construction&quot...

shei, Some thoughts about your problem: If the load on the truss remained the same, the axial force in the web members would increase 32%. The added back-to-back angles, if they are of the same size would double the capacity of the member, that is more than enough. Another way to reinforce...

Anthonyc007, The book "Formulas for Stress and Strain" by Roark have formulas for partial uniform load on single span with different support conditions. I do not include the formulas here because they need a sketch. If you want to see the pertinent book page, let me know your...

Lufti, I would check two items: 1) That the distance from the deflected power lines (at maximum sag) to any not insulated object complies with the clearances specified on the Electrical Code. 2) That the frame is stiff enough not to produce a dynamic problem if the presence of wind...