Each pylon of the cable stayed bridge has a cable that supports the deck and a backstay. Say the supporting cables carry 70% of the weight of the bridge which weighs 50 Mg. Even though the pylon is built-in at the bottom, the tensions in the backstays are chosen so that the net horizontal force on a pylon due to the two cables is zero. Say the steel pylon consists of two separate box sections, 800 mm x 1000 mm 20 mm thick on the two sides of the deck that join at a certain point above the deck. Let the cables be attached to the pylons at height h, below which the two box sections are separated and equally share the loads of the cables. Determine the maximum allowable height, h, if the box sections are not to buckle in the weaker direction. Take the angles
