Figure Q3(b) shows a girder bridge provided with a floor system comprising stringers and floor beams so that all loads applied to the floor will be transmitted to the bridge only through the floor beams at the panel points. The girder bridge is hinge-supported at A and E, and roller-supported at 1. The half joint at D may be considered as a roller. Figure Q3(b) also shows a heavy truck with the axle loads P1 and P2, and axle spacings P. 3 of 17 S1 and S2 indicated. The truck may run on the bridge in both directions. Show how the truck should be arranged to produce critical shear force VEF in panel EF of the girder due to live load effects and determine their magnitudes. Parameters P1, P2, S1 and 52 can be obtained from Table Q3(b) according to the university number. State clearly the sign conventions adopted. (10 marks) P1 = 30KN P2 P3140KN S1 = 4.3m S2 = 6.3m I B I C I I E VEF F A 8 panels @10 m = 80 m Girder bridge (not to scale) D P (kN) P (KN) S (m) S (m) Heavy truck Figure Q3(b) I G P2 (KN) I H H