EXPERIMENT STUDY ON STEEL-ANCHOR-BOX OF CABLE-PYLON IN SHANGHAI YANGTZE RIVER BRIDGE

A recently developed steel-anchor-box was adopted in the cable-pylon anchorage zone of the Shanghai Yangtze River Bridge with the largest cable-force of 1127 tons. Due to the complex fabrication and large number of plates being used, a thorough investigation on the mechanical behavior of the steel-anchor-box is required. The experimental and numerical studies are presented in this paper. The stresse distributions in the plates are obtained and the loading transmitting among the plates is determined. Comparing the FEM results with experimental results, the accuracy of the numerical method is verified. The stresse distribution in the plates is non-uniform. Under the normal design cable force, the steel-anchor-box behaves in elastic range, but the stresses at some locations of the plates are larger than the design strength prescribed by the current code. The deformation of the steel-anchor-box is small even under loads which produce 1.7 times of the design cable force. Hence, it is suggested that partial plasticity be permitted in the steel-anchor-box, as long as the structural safety is not impaired significantly.