A rigid true triaxial apparatus for analyses of deformation and failure features of deep weak rock under excavation stress paths  

作　　者：Xia-Ting Feng Xiaojun Yu Yangyi Zhou Chengxiang Yang Feiyan Wang 

机构地区：[1]Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,School of Resources and Civil Engineering,Northeastern University,Shenyang,110819,China [2]Key Laboratory of Liaoning Province on Deep Engineering and Intelligent Technology,Northeastern University,Shenyang,110819,China

出　　处：《Journal of Rock Mechanics and Geotechnical Engineering》2023年第5期1065-1075,共11页岩石力学与岩土工程学报（英文版）

基　　金：the financial support from the 111 Project(Grant No.B17009);the Liao Ning Revitalization Talents Program(Grant No.XLYCYSZX1902).

摘　　要：The squeezing scenario in deep weak rock tunnels can hinder underground construction.However,due to the limitations of test technologies at hand,the real excavation stress path cannot be mimicked in the laboratory.Thus,the large deformation mechanism of deep weak rocks still remains unclear.For this,a true triaxial apparatus(TTA)to investigate the mechanical responses of deep weak rock under excavation stress paths in field and reveal the squeezing mechanism of deep tunnels is assembled and developed at Northeastern University,China.The apparatus can perform instantaneous unloading in s3 direction based on electromagnetism technology.In addition,uniform loading and deformation measurements can be carried out based on the proposed linked interlocking clamp and antifriction device,even if the sample has a strong dilatation deformation performance.Next,a bore trepanning is designed to capture noiseless acoustic emission(AE)signals for deep weak rock at a low threshold.Finally,two tests were are conducted using this instrument to preliminarily understand the failure and deformation features of deep weak rock based on fractured marble.The results show that the complete stressestrain curves of fractured marble have the characteristics of low strengths and large deformations,and the larger deformation and the more serious failure occur when the fractured marble enters the post-peak state after excavation.The results show that the developed apparatus is likely to be applicable for deep weak rock engineering.

关 键 词：True triaxial apparatus(TTA) Deep weak rock Large deformation Excavation stress path Instantaneous unloading 

分 类 号：TU45[建筑科学—岩土工程]