1000 SE EVERETT MALL WAY BASE FILE 2018-01-01 MF Import

Flan Check 17�2 Larry Callahan September 10, 1905 Page 7'wo 4. g. Design of fooings in ductile frames: The bending moments at the base of the columns, which are transmitted by the footings to the soil, are approximately equal for the full liv� load case and the no live load case. However, the moment arm (e) on the footing (i.e. e = M/P) increases for the de�d lod only condition and should be considered when calcu- lating tlie soil pressure. 5. b. Beam-column joints which ai e not within (and parallel to) the ductile frames: When only portions of the structural frame are ductile, P.20-C of the S�AOC Commentary stipuiates: "The larger displacements. . . (of ductile frames) must not jeopardize the vertical load capabilities of all oiiier load ca;ryiny elemen[s not part of tlie seismic 'resisting systern." O��r recommendation for a framin� member placed in both directions at every column is based on this. It ultimately shoulci be left to the dis- cretion of the engineer, but taking into account the SEAOC requir•ement. c. Beam-to-column con�ections in ductile frames: Mr. Griffir has referenced P.81-C of the SEAOC Commentary for desiyn of the conneciions. Note that P.87-C st�tes "a full penetration welded web connection. . .would develop somewhat greater ductility than the bolted web." UBC Section 2722(d) is more specific: '4�ach beam or girder moment connection to a column shall be capable of dee2loping in the beam the full plastic capa- city of the beam or girder" unless "it can be shown that adequtely duc- tile joint displacement capacity is provided with a lesser connection." The connection as detailed does not deve!op the plastic moment czpacity of the beam f�.e. area of flange times beam depth is only about 2/3 of the plastic section modulus) . The connection detail, therefore, requires justification to demonstrate that adequaYe ductile joint displacement is provided. d. Adequacyof doubler plates: The designer hz- indicated 50 Icsi stee;. The note at the bottom of the doubler plate schedule states "plates a�c ASTht A36 at columns." Some clarification of the drawings appears ap- propriate. 6. b. The details of the suspended ceiling will have to �e much more speci- ' fic to really assure :hat a 2 hour floor/ceiling assembly is achieved. Refer to Evaluation Report PFC 2896 and Architectural Section d/A-9. 7. c. Test data and yuality-control program for "Tat`trus" girders: For your information. 10. b,e,f. Design of skylights, canopies, suspended ceilings, curtain walls, etc. by manufacturer for wind pressures and lateral deflections: These should be submitted to }'ou prior to fabrication ior review. � .