Study on Critical Span for the Anti-slip Stability between Main Cable and Saddle of Multi-Span Suspension Bridges

Abstract:

The stiffness of middle tower and the anti-slip stability between cable and saddle on the top of middle tower are the key issues of designing multi-span suspension bridges.The critical span for the anti-slip stability on the rigid and flexible middle tower is established through theoretical analysis.Then, a comparative study on the anti-slip capacity of the bridges with box girder and truss grider is conducted. Finally, the principle of choosing anti-slip factor is discussed.The results indicate that anti-slip factor is mainly related to the ratio of dead to live load and the length of span.And it is larger with increase of the span.When the critical span is reached,the anti-slip requirement on the rigid middle tower is satisfied automatically.The critical span of flexible middle tower decreases approximately linearly with increase of the displacement of tower.