The superstructure of a bridge (everything from the girders up) is being modified, and as a result it will receive more wind load than it was originally designed for. The team leader wants us to...

The superstructure of a bridge (everything from the girders up) is being modified, and as a result it will receive more wind load than it was originally designed for. The team leader wants us to calculate the lateral drift of the bridge under the new wind load. The leader wants to know if the drift exceeds h/250. 54 kN The barrier at ground level looks like a beam but is not connected in a way that would help resist lateral load. Therefore, the substructure and wind load can be idealized as shown.

a. Guess the anticipated deflected shape for the frame. b. Predict the drift using the Stiff Beam Method. Should the prediction overestimate or underestimate drift, or can't you be sure? c. Predict the drift using the Virtual Work Method. Should the prediction overestimate or underestimate drift, or can't you be sure? Should this prediction be better or worse than the prediction in part (b)? d. Using the largest result from parts (b) and (c), compare the predicted drift to the drift limit. Evaluate the adequacy of the existing frame to carry the new wind load. e. Predict the drift using structural analysis software. Because of axial shortening of the beams, the drift value i ~.O m will be different at different joints; the best comparison will be at joint H, since all of the beam shortening happens to the left of that column line. £ Submit a printout of the displaced shape. Identify at least three 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? Make a comprehensive argument to justify your answer. i. Comment on why your guess in part (a) was or was not close to the solution in part (f).