拉拔过程中全长灌浆锚固系统能量演化规律  

Energy evolution law of fully grouted anchorage system during pulling process

作　　者：刘秀军 马占国[1] 付文光 LIU Xiujun;MA Zhanguo;FU Wenguang(State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Shenzhen Geotechnical Investigation&Surveying Institute(Group)Co.,Ltd.,Shenzhen,Guangdong 518028,China;Shenzhen GongKan Geotechnical Group Co.,Ltd.,Shenzhen,518063,China)

机构地区：[1]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 [2]深圳市勘察测绘院(集团)有限公司,广东深圳518028 [3]深圳市工勘岩土集团有限公司,广东深圳518063

出　　处：《工程建设》2024年第9期1-7,共7页Engineering Construction

基　　金：国家重点研发计划资助项目(2019YFE0118500、2019YFC1904304);国家自然科学基金资助项目(U22A20598、52104107)。

摘　　要：锚固系统的拔出破坏实质上是能量驱动的失稳破坏,能量演化规律能充分反映锚固系统的承载性状和失效破坏过程。为了揭示循环荷载作用下全长灌浆锚固系统变形破坏过程中的能量转化机制及损伤劣化过程,文章基于热力学第一定律,给出了锚固系统在拉拔过程中的输入能、弹性能、耗散能、阻尼能以及损伤能等能量计算公式,并结合某项目全长灌浆锚索的现场拉拔试验,系统地研究了拉拔过程中全长灌浆锚固系统内部的能量演化规律。研究结果表明:1)随着循环次数和拉拔荷载的增加,输入能、弹性能、阻尼能以及损伤能均在逐渐增加,当拉拔荷载接近于极限抗拔力时,损伤能会呈现出急速增加的现象;2)在拉拔过程中,弹性能的变化幅度较小,其占比始终维持在50%左右;3)阻尼能和损伤能的演化是一个“此消彼长”的过程,阻尼能的占比曲线呈倒“U”型,其占比总体来说维持在20%以下,而损伤能的占比曲线大体呈“U”型,且其随着荷载比的变化幅度相对较为明显;4)全长灌浆锚固系统在拉拔过程中会产生较大的塑性损伤能,该过程实际上是不断损伤、刚度逐渐劣化的过程。本文成果对全长灌浆锚固系统的设计、施工、检验及监测预警具有一定借鉴意义。The pull-out failure of the anchorage system is essentially an energy driven instability failure,and the energy evolution law can fully reflect the bearing behavior and failure process of the anchorage system.In order to reveal the energy conversion mechanism and loss degradation process of the deformation and failure process of the fully grouted anchorage system under cyclic loading,this paper provides energy calculation formulas for the input energy,elastic energy,dissipation energy,damping energy,and damage energy of the anchorage system during the pulling process based on the first law of thermodynamics.Combined with the on-site pull-out test of a certain project's fully grouted anchor cable,the energy evolution law inside the fully grouted anchorage system during the pulling process is systematically studied.Research has shown that:ⅰ)With the increase of the number of cycles and pull-out load,the input energy,elastic energy,damping energy,and damage energy all gradually increase.When the pull-out load approaches the ultimate pull-out resistance,the damage energy will show a rapid increase phenomenon.ⅱ)During the drawing process,the change in elastic energy is relatively small,and the proportion of elastic energy remains around 50%.ⅲ)The evolution of damping energy and damage energy is a p rocess of trade-off.The proportion curve of damping energy shows an inverted"U"shape,and the proportion of damping energy generally remains below 20%,while the proportion curve of damage energy generally shows a"U"shape,and its variation amplitude with the load ratio is relatively obvious.ⅳ)The fully grouted anchorage system will generate significant plastic damage energy during the pulling process,and the process of being pulled out is actually a continuous process of damage and gradually deteriorating stiffness.This paper has certain reference significance for the design,construction,inspection,monitoring and early warning of the fully grouted anchorage system.

关 键 词：全长灌浆锚固系统 拉拔试验 滞回曲线 能量演化规律 热力学第一定律 

分 类 号：TU470.3[建筑科学—结构工程]