The dead load of the prestress girder is balancing the pulled strands. That's why while transporting if Girders are rotated, they explode. When we cut the bridge we might be changing this equilibrium also.
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We know that when there is moment and axial load on footing we find eccentricity "e" =M/P and the footing is at least e times 6 long in direction of moment to avoid any tension in soil.
In order to decrease e (by increasing p) can we add the dead weight of proposed footing also in "p".
