Economic and Mechanical Properties of Super-long Span Cable-stayed Bridge with V-shaped Pylon

Two finite element models are established for super-long span cable-stayed bridges with V-shaped pylon or with conventionally erected pylon.Then,some economic and mechanical properties are given by comparative study method.Compared with the bridge with the erected pylon,constructive materials can be saved from the bridge with V-shaped pylon.From the derived formula of material saving of pylon and cables,the optimum effect occurs when the inclination of V-shaped pylon is half of the inclination of farthest cable,and the pylon materials save 6% while cable materials save 1%.Since the V-shaped pylon cable-stayed bridge has a lower height of tower and the shortened hoisting cable and the decreased moment of tower root by about 26%,the inclination of cables in this structural system is larger and the overall stiffness is increased.As a result,the stability factor is improved.In addition,the V-shaped pylon cable-stayed bridge manifests a better resistance than conventional bridge under horizontal wind load,which is more adaptable to the development of cable-stayed bridge towards a longer span.