Limit Span of Two-Span Self-Anchored Suspension Bridge

Self-anchored suspension bridges are increasingly appreciated by engineers for their aesthetic look, low cost and more adaptive for geological environment than earth-anchored suspension bridges. Many self-anchored suspension bridges have been completed or are in construction in the world. For huge horizontal component of main cable force in the stiffening girder and the different construction method, self-anchored suspension bridge has much less limit span than earth-anchored suspension bridges. In this paper, the limit span of two-span self-anchored suspension bridge with single pylon is deduced. Some factors, such as ratio of sag to span of main cable, ratio of side-span to main-span, ratio of height of pylon to main-span, second dead load and live load, are analyzed. Based on the common used materials and considering the main influencing factors, the limit spans of self-anchored suspension bridges with concrete stiffening girder and with steel stiffening girder, are discussed in detail, and the corresponding limit spans are given. Based on the study, the measures to enlarge span length of self-anchored suspension bridge are presented.