7-12. The frame shown in the accompanying figure is unbraced against sidesway about the x-x axis. The columns are W8 and the beams are W12 x 16. ASTM AS72 steel is used for the columns and beams. The beams and columns are oriented so that bending is about the x-x axis. Assume that K, = 1.0, and for column AB the service load is 175 k, in which 25 percent is dead load and 75 percent is live load. Select the lightest W8 shape for column AB. Moment connection. Typ 13 ft 20 ft 20 ft 20 ft FIGURE P7.12

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A rectangular tied braced column is reinforced with 6-28mm bars as shown in the figure below. Check the adequacy of the column for the following gravity loads: - - - - - - Service dead load = 1050kN Service live load = 850 kN Service dead load moment = 39 kN-m Service live load moment = 27 kN-m top=bott. = 1.0 40 lu = 5.0m f = 27.6 N/mm², fy = 414 N/mm² axis of bending 500mm Ties 10mm@300c/c } 350mm At eccentricity of 40mm P M +40 + 500mm MU +40- P Top end Bott. end

Please Determine the axial load strength and moment (without and with reduction factor) a square columns for the following conditions and draw their interaction diagrams (note the scale): When conditions are in balance During the tensile condition When the pressure condition Pure axial Pure moment