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1. A small bridge is carrying a truck moving from left to right. Using influence lines for beams: a. Compute the max. ordinate of the influence line to obtain max positive moment at point B. b. Compute the position of P1 from point A to produce maximum positive moment at B. c. Compute the maximum positive moment at B due to the series of concentrated loads. P1 P2 P3 AA B D 4m 4m 2m Truck wheel loads: P1 P2 P3 2m 3m P1 = 145 P2 = 120 P3 = 70
analyze as continuous beam ELEVATION L L1 L L1 -- Span 1 Span 2 Span 3 Span 4 H abutment pier USING THREE-MOMENT EQUATION: 2. Analyze the bridge shown in the figure above. Using influence diagrams, it has been determined that in order to produce the maximum positive moment in Span 2, a uniform load, w must be loaded fully in Spans 2 and 4. Determine the reactions at the pier supports (assume abutments to be roller supports and piers to be pin supports) and draw the shear and moment diagrams. 3. Analyze the same bridge with the uniform load, w fully loaded in spans 2 and 3. Determine the reactions and draw the shear and moment diagrams. W = 9 kN/m L = 13 m L1 = 8m