Study on temperature field distribution characteristics and fire resistance performance of pin-connected cable clamps in suspension bridges under fire conditions

This study focuses on pin-connected cable clamps and develops a numerical model of a tanker truck fire using the Fire Dynamics Simulator (FDS) to analyze the ambient temperature distribution around the cable clamp. A refined finite element model of the clamp is established, and a sequential thermal-mechanical coupling method is employed to systematically investigate the temperature field distribution, structural strength failure modes, and anti-slip performance evolution of the clamp under high-temperature fire conditions. The results indicate that under the combined effects of cable force and temperature, failure initially occurs at the pin hole of the lower clamp ear plate. When the clamp is installed at a height exceeding 16 m, no strength failure occurs within 60 min. For clamps at a height of 12 m, slip failure occurs under all horizontal thrust conditions due to the influence of high temperature and variable friction coefficients, with the fire resistance limit decreasing significantly as the horizontal thrust increases. Based on the analysis, calculation formulas for the anti-slip frictional resistance of the clamp under high-temperature conditions and corresponding fire protection measures are proposed.