全长灌浆锚固系统在不同加载历程下的抗拔性能响应特征分析  

Analysis of the Response Characteristics of the Pull-out Performance of the Fully Grouted Anchorage System under Different Loading Histories

作　　者：刘秀军 付文光 LIU Xiujun;FU Wenguang(Shenzhen Geotechnical Investigation&Surveying Institute(Group)Co.Ltd.,Shenzhen 518028,Guangdong,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China;Shenzhen GongKan Geotechnical Group Co.Ltd,Shenzhen 518063,Guangdong,China)

机构地区：[1]深圳市勘察测绘院(集团)有限公司,广东深圳518028 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116 [3]深圳市工勘岩土集团有限公司,广东深圳518063

出　　处：《科技和产业》2024年第20期301-312,共12页Science Technology and Industry

摘　　要：依托“深坪锚索综合试验项目”的23根全长灌浆锚索的49次拉拔试验数据及结果,对试验锚索在不同拉拔试验方法下的试验结果进行横向和纵向对比分析,探讨了锚固长度、蠕变率以及加载历程参数与全长灌浆锚固系统抗拔性能间的关系,分析了拉拔过程中抗拔刚度的变化规律,并基于锚固界面剪切刚度不断劣化的推论,对全长灌浆锚固系统的循环加、卸载过程进行了模拟。结果表明,锚固系统的抗拔性能主要受拔出力和锚头位移两个指标控制,一味地增加锚固长度并不能有效地增加其抗拔性能;按蠕变率大于2.0mm的蠕变稳定指标来判定锚固系统是否达到破坏状态是更为稳妥和有效的方法;随着试验次数、试验总用时、所经历循环次数的增加,锚固系统在较低的荷载水平下抗拔性能会相应的提高,而在较高的荷载水平下其抗拔性能却在降低;全长灌浆锚固系统在拔出过程中会产生较大的塑性损伤,其抗拔刚度会逐渐劣化;在循环拉拔荷载作用下的锚固系统的模拟计算中,采用不断劣化的锚固界面剪切刚度进行计算,能够较好的刻画出循环加、卸载过程及塑性滑移过程。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.

关 键 词：全长灌浆锚固系统 拉拔试验 加载历程 抗拔性能 刚度劣化 

分 类 号：TU470.3[建筑科学—结构工程]