Experimental Study on Impact Force Factor during Sudden Cable Loss in Cable-Stayed Bridges

摘要

Cable element plays an important role in cable structures including cable supported long span bridges. To increase structural robustness and prevent progressive collapse, cable in cable-stayed bridge is generally designed with sufficient redundancy. However, in some extreme events, the cable can be abruptly broken. Impact force factor of 2.0 is suggested by the PTI's "Recommendations for Stay Cable Design, Testing and Installation". This study seriously placed the cable loss phenomenon under consideration. Firstly, description of impact force factor and classification of cable loss event were discussed. Secondly, rod breaking experiment was carried out to determine the values of impact force factor in three breaking patterns; remarkable behaviours of the specimens were also highlighted via strain waves obtain from the tests. Finally, recommendations for appropriate impact factor and approach method for this relatively new field of study were issued.