The architect wants an open layout for a new medical facility. Therefore, the best lateral load-resisting system is a rigid frame. The floors and roof are concrete on metal decking, so they act one-way. The resulting dead load on an interior frame is a uniform distributed load. In order to make preliminary selection of member properties, the team leader would like an idea of the internal forces in the beams. At the same time, the geotechnical engineer would like to know the preliminary results for the requirements on the foundations.
a. Guess the direction of each of the reactions at the base of columns B1 and B2.
b. List the assumptions you make in order to perform an approximate analysis of the frame.
c. Use approximate analysis to determine the peak positive and negative moments for the roof beams and the other floor beams.
d. Use approximate analysis to find the reactions at the base of columns B1 and B2.
e. To demonstrate the effectiveness of approximate analysis, use structural analysis software to find the peak positive and negative moments for the roof beam and other floor beams for bay B1-B2. Also find the reactions at the base of columns B1 and B2. An experienced member of the team recommends we preliminarily estimate that all of the beams will be steel (E = 200 GPa = 200 kN/mm2 ) W530 x 82s (A = 1.045 x 104mm2, 1= 4.75 x10$mm4) and all of the columns will be steel W310 x 86s bending about their weak axes (A = 1.097 x 104 mm2, I = 4.45 x 10~ mm4 ) .
f. Submit a printout of the displaced shape. Identify at least four features that suggest the displaced shape is reasonable.
g. Verify equilibrium of the computer aided analysis results.
h. Are the results of your computer aided analysis reasonable?
i. Make a comprehensive argument to justify your answer. j. Comment on why your guess in part (a) was or was not close to the solution in part (d).
