Laboratory investigation into effect of bolt profiles on shear behaviors of bolt-grout interface under constant normal stiffness (CNS) conditions  

作　　者：Guojian Cui Chuanqing Zhang Yibin Pan Liang Deng Hui Zhou 

机构地区：[1]State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan,430071,China [2]University of Chinese Academy of Sciences,Beijing,100049,China [3]PowerChina Huadong Engineering Corporation Limited,Hangzhou,310014,China [4]College of Civil Engineering and Architecture,China Three Gorges University,Yichang,443002,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2020年第6期1234-1248,共15页岩石力学与岩土工程学报（英文版）

基　　金：This study is supported by the key projects of the Yalong River Joint Fund of the National Natural Science Foundation of China(Grant No.U1865203);the National Key Research and Development Program of China(Grant Nos.2019YFC0605103,2019YFC0605100);the National Natural Science Foundation of China(Grant No.51279201).The partial support from the Youth Innovation Promotion Association CAS is gratefully acknowledged。

摘　　要：Rock bolts have been widely used for stabilizing rock mass in geotechnical engineering.It is acknowledged that the bolt profiles have a sound influence on the support effect of the rock bolting system.Previous studies have proposed some optimal rib parameters(e.g.rib spacing);unfortunately,the interface shear behaviors are generally ignored.Therefore,determination of radial stress and radial displacement on the bolt-grout interface using traditional pull-out tests is not possible.The load-bearing capacity and deformation capacity vary as bolt profiles differ,suggesting that the support effect of the bolting system can be enhanced by optimizing bolt profiles.The aim of this study is to investigate the effects of bolt profiles(with/without ribs,rib spacing,and rib height)on the shear behaviors between the rock bolt and grout material using direct shear tests.Thereby,systematic interfacial shear tests with different bolt profiles were performed under both constant normal load(CNL)and constant normal stiffness(CNS)boundary conditions.The results suggested that rib spacing has a more marked influence on the interface shear behavior than rib height does,in particular at the post-yield stage.The results could facilitate our understanding of bolt-grout interface shear behavior under CNS conditions,and optimize selection of rock bolts under in situ rock conditions.

关 键 词：Bolt profile Constant normal stiffness(CNS) Shear test Interface failure characteristics Shear behaviors 

分 类 号：TU476[建筑科学—结构工程]