Influence of confining stress on fracture characteristics and cutting efficiency of TBM cutters conducted on soft and hard rock
来源期刊：中南大学学报(英文版)2015年第5期
论文作者：LIU Jing-shuo CAO Ping LIU Jie JIANG Zhe
文章页码：1947 - 1955
Key words：triaxial testing machine; numerical study; tunnel boring machine (TBM) cutter; confining stress; soft and hard rock; cutting efficiency
Abstract: Combined with numerical simulation, the influence of confining stress on cutting process, fracture conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine (TRW-3000) designed and manufactured in Central South University (China). Results are obtained by performing analysis on the fracture scopes of cement and granite plates, the characteristics of cutting force in cutting processes and the cutting efficiency. Firstly, the increase of latitude fracture scope and the decrease of longitude fracture scope are both more notable in the tests conducted on cement plates subjected to the increasing confining stresses; secondly, the increase tendency of peak penetration forces obtained from tests conducted on granite plates is more obvious, however, the increase tendencies of average penetration forces achieved from cement and granite plates are close to each other; thirdly, the cutting efficiency could be improved by increasing the spacing between cutters when the confining stress which acts on soft and hard rock increases in a certain degree, and the cutting efficiency of soft rock is more sensitive to the varying confining stresses.
LIU Jing-shuo(刘京铄), CAO Ping(曹平), LIU Jie(刘杰), JIANG Zhe(蒋喆)
(School of Resources and Safety Engineering, Central South University, Changsha 410083, China)
Abstract:Combined with numerical simulation, the influence of confining stress on cutting process, fracture conditions and cutting efficiencies of soft and hard rock has been conducted on the triaxial testing machine (TRW-3000) designed and manufactured in Central South University (China). Results are obtained by performing analysis on the fracture scopes of cement and granite plates, the characteristics of cutting force in cutting processes and the cutting efficiency. Firstly, the increase of latitude fracture scope and the decrease of longitude fracture scope are both more notable in the tests conducted on cement plates subjected to the increasing confining stresses; secondly, the increase tendency of peak penetration forces obtained from tests conducted on granite plates is more obvious, however, the increase tendencies of average penetration forces achieved from cement and granite plates are close to each other; thirdly, the cutting efficiency could be improved by increasing the spacing between cutters when the confining stress which acts on soft and hard rock increases in a certain degree, and the cutting efficiency of soft rock is more sensitive to the varying confining stresses.
Key words:triaxial testing machine; numerical study; tunnel boring machine (TBM) cutter; confining stress; soft and hard rock; cutting efficiency
