Safety method of construction a prestressed cable-stay bridge

A method of construction a prestressed cable-stay bridge comprising:

• At least a tower including a pier founded on a ground, a pair of masts parallel extending upward from a top of the pier at predetermined elevation having on a middle part thereof integrated with a transverse girder means which supports on a deck member including a pair of corbel means transversely and releasably engaging, into a pair of dovetail grooves in an under side adjacent two longitudinal ends thereof, a main beam secured on its central part to the deck member along the longitudinal axis of said bridge and suspended at four corners by a plurality of temporal stay cables from an anchoring means on an outer side adjacent the top of the masts, a pair of sub-beam longitudinally coupled with two longitudinal ends of the main beam respectively and suspended at lateral side of their free ends by two pairs of additional temporal stay cables from the top of the masts with their free ends engaged with a corresponding sub-beam from additional towers, an upper portion and a plurality of segments mounting respectively to the top of the main beam and the sub-beams which are respectively conducted of on the spot prestressing procedure by suitable means prior to secured to the beams by suitable fastening means, a plurality of first and second side reinforcements securing to a pair of longitudinal gaps along each of the lateral sides of said bridge between the upper portion and the main beam and/or the segments and the sub-beams, two sheets of permanent stay cables instead of the temporal stay cables suspending the beams form the top of the masts wherein the upper end of each sheet of the permanent stay cables securing to an anchoring means on an inner side adjacent the top of the masts and their lower ends securing spaced apart to respective lateral edges of the beams and a roadway is paved on the upper surface of said bridge.