Research on an Anchoring System of Isodirectionally Turning Stay Cable

Abstract

Along with the innovation and development of tower, main girder and stay cables, cable-stayed bridge has become the most common structure form of long-span bridges. Although the stay cable system has been developed all the time, the durability of cable anchoring zone on the tower remains one of the key issues encountered by engineers. In recent years, in order to improve the durability of anchorage zone, prestressed anchorage, steel anchor beam anchorage and steel anchor box anchorage techniques emerged successively. However, these types of anchorage cannot completely avoid tensile stress, and require certain measures to control the tensile stress. If the tensile stress is out of control, the cable tower will be in the risk of cracking, which will affect the durability of cable anchoring zone. A new concept of plan looping cable system is used in the background project for the first time, which applies the saddle anchorage technique in long-span bridges. Transition pipes are used to stretch the saddles out of the cable tower and reeve steel strands through the saddles. Heteromorphosis stainless steel dividing pipes are used to improve the clamp safety, and non-grouting method is used to improve the replacement convenience of steel strands. Cable force is transferred to the pylon as circular radial pressures, which avoids tensile stress and improves the durability of cable tower.