荷载分配式复合锚杆在分层岩土体中的应用研究  

Research on the Application of Load Distribution Type Composite Anchors in Layered Soil and Rock Massn

作　　者：刘玉果 夏凯 张明礼[2] 张鑫 马彦清 Liu Yuguo;Xia Kai;Zhang Mingli;Zhang Xin;Ma Yanqing(China Construction Fourth Engineering Bureau Co.,Ltd.,Guangzhou 510000,P.R.China;Key Laboratory of Disaster Prevention and Mitigation in Civil Engineering of Gansu Province,Lanzhou University of Technology,Lanzhou 730050,P.R.China)

机构地区：[1]中国建筑第四工程局有限公司,广州510000 [2]兰州理工大学甘肃省土木工程防灾减灾重点实验室,兰州730050

出　　处：《地下空间与工程学报》2025年第1期272-282,共11页Chinese Journal of Underground Space and Engineering

基　　金：甘肃省高等学校产业支撑计划项目(2020C-40);甘肃省基础研究创新群体项目(20JR5RA478)。

摘　　要：岩土体强度分层导致锚杆各单元锚固段极限承载力不同,使得锚杆锚固效果降低。设计了一种荷载分配式复合锚杆,在受地下水浸湿影响导致中风化泥岩强度出现分层的深基坑中进行原位试验。结果表明:(1)荷载分配式复合锚杆承载力是同长度拉力锚杆的1.52倍以上,是同长度荷载分散型复合锚杆的1.13倍以上,且其结构延性更优;(2)中风化泥岩浸水后,锚杆第二界面抗剪强度损失高达66%,直接导致了锚杆各单元锚固段极限承载力不同,影响了荷载在锚固段内的传递与分布;(3)荷载分配式复合锚杆各单元锚固段实际承担荷载与其极限承载力接近,实现了依据锚杆各单元锚固段极限承载力对锚头荷载按比分配的目的;(4)锚头荷载按比分配后,锚杆的结构延性更好,能够有效避免锚杆提前在薄弱点发生破坏,并阻止了锚杆受力过程中各单元锚固段之间裂缝的产生,锚杆使用寿命得到延长;(5)荷载分配式复合锚杆在锚固段内对岩土体强度得到更高的调用,在岩土体强度出现分层的锚固工程中适用性更强,经济效益更好。The strength stratification of the rock and soil mass results in different ultimate bearing capacities for each segment of the anchor rod,leading to a reduction in the anchoring effect.A load-sharing composite anchor rod was designed for an in-situ test in a deep foundation pit where the strength of weathered mudstone was stratified due to the influence of underground water seepage.The results indicate that:(1)The bearing capacity of load-distributed composite anchor rods is more than 1.52 times higher than that of tension-only anchor rods of the same length,and is more than 1.13 times higher than that of load-dispersed composite anchor rods of the same length.Thus,the bearing capacity of the anchor rods has been further improved.(2)After immersion in water,the second interface shear strength of the anchor rods in moderately weathered mudstone is reduced by up to 66%,resulting in different ultimate bearing capacities of the anchor rod units.This affects the transfer and distribution of loads within the anchor rod sections.(3)The load distribution composite anchor rod ensures that each unit anchoring section carries a load close to its ultimate bearing capacity,achieving the goal of proportional distribution of anchor head loads based on the ultimate bearing capacity of each unit anchoring section.(4)By proportionally distributing the anchor head load,the structural ductility of the anchor rod is enhanced,effectively avoiding premature failure of the anchor rod at weak points.At the same time,this can also prevent the occurrence of cracks between the unit anchoring sections during the loading process.Therefore,the service life of the anchor rod is extended.(5)The load distribution composite anchor rod can provide internal support to the rock within the anchoring section,effectively improving the stability and load-bearing capacity of the surrounding rock mass.This helps prevent the occurrence of geological disasters such as rock burst and collapse,ensuring the safety and reliability of engineering structures.Addit

关 键 词：锚固工程 岩土体强度分层 荷载分配式复合锚杆 强度损失 承载特性 

分 类 号：TU413[建筑科学—岩土工程]