Reader Forum

is it possible to use ASTM A 572 grade 50 in plates up to 5"?,if not, which is the recommended steel for substitute in a Bridge structre application

In the Erection section, the statement "It should be understood that anchor rods cannot be pretensioned ——" is not correct.  It is possible, and in some cases advantageous, to pretension anchor rods.  For pretensioning, it is necessary to use a washer, larger plate or other shape (i.e angle) at the embedded end nut or bolt head. Relying on bond to resist uplift of any kind is never acceptable.

Manuel Morden, S.E.   F SEAOC

dear sir/madam

I want to know if the "R" is different in ASD or LRFD method, is it depend on load combinations also?

thanks before

For portal frame rafters, what is magnitude of the force subjected to the knee brace resulting from preventing the rafter compression flange to deform?

a friend of mine told me that it’s about 5% of the compression force in the rafter

if it’s x%…then x is the force resulted from the laterlal torsional buckling at the particular point…?

I have a tapered Column and a Haunched rafter, how can I get "K" from the Chart while the Column’s moment of Ineria is not uniform along the column and rafter’s length…?

In Table 14-9 (continued), of the thirtenth edition of the AISC manual, at the center point of the splice the bolt c/c dimention goes to 3 1/2″ in stead of 3″. What is the reason for this?

How we consider the roof deck span condition like single span,two span, three span condition?

Is it a bad idea to galvanize and embeds or other carbon steel items that will have contact with concrete? Should the detailer bring up this issue with the EOR if the contracts call for all embeds to be galvanized, or is this no long a big issue?

can anyone direct me to a fabricator for concrete filled HSS columns in California? 

Are SC Bolts are manufactured? Or they are the A325N bolts with the LIW washers….Please advise