Analysis of the Response Characteristics of the Pull-out Performance of the Fully Grouted Anchorage System under Different Loading Histories
Based on the 49 pull-out test data and results of 23 fully grouted anchor cables in the"Shenping Anchor Cable Comprehensive Test Project",a horizontal and vertical comparative analysis was conducted on the test results of the test anchor cables under different pull-out test methods.The relationship between anchorage length,creep rate,loading histories parameters and the pull-out performance of the fully grouted anchorage system was explored,and the variation law of pull-out stiffness during the pull-out process was analyzed.Based on the inference of the continuous deterioration of shear stiffness at the anchorage interface,the cyclic loading and unloading process of the fully grouted anchorage system was simulated.The results are as follows.The pull-out performance of the anchorage system is mainly controlled by two indicators:pull-out force and anchor head displacement.Simply increasing the anchorage length cannot effectively improve its pull-out performance.It is a more reliable and effective method to determine whether the anchorage system has reached a failure state based on the creep stability index with a creep rate greater than 2.0 mm.As the number of tests,total test time,and number of cycles experienced increase,the pull-out performance of the anchorage system will correspondingly improve at lower load levels,but its pull-out performance will decrease at higher load levels.The fully grouted anchorage system will cause significant plastic damage during the pull-out process,and its pull-out stiffness will gradually deteriorate.In the simulation calculation of the anchorage system under cyclic tensile load,the continuously deteriorating shear stiffness of the anchorage interface is used for calculation,which can better depict the cyclic loading and unloading processes and plastic sliding processes.