Experimental Study of Slip Resistance of Cable Clamps of Hongdu Bridge

In order to understand the actual slip resistant performance of the cable clamps of self-anchored suspension bridges,the Hongdu Bridge was cited as an example.A method of the combination of full-scale model test and finite element analysis for the real bridge was taken to study the attenuation law of the bolt axial force,stress distribution and anti-slip friction coefficient of the cable clamps of the self-anchored suspension bridge.The results of the analysis indicated that the attenuation of bolt axial force was fast at the beginning stage,and then gradually became slow,the final effective axial force of the bolt was about 80% of the design axial force;the inner stress in each cable clamp gradually diminished from the point where the load was applied to the end of the cable clamp;the maximum stress in the cable clamp under the action of slip thrust was generally greater than that under the action of design thrust.The greater bolt axial force gave rise to the greater cable clamp stress in the corresponding location,which implied that the inner friction force of the cable clamp along the axial line of the main cable did not follow the law of ideal linear distribution.The measured anti-slip friction coefficient of the cable clamp was 0.25,greater than the value of 0.15 suggested in the code,and the measured value was relatively safe.It is advised that in the construction,the bolt be tightened from the two ends towards the center and by the way of diagonal tightening,the uniformity of the tightening force for the bolts should be controlled,and the bolts be repeatedly tightened before each critical operation.