摘要
为实现对峰前及峰后岩石脆性特征的定量刻画,提出了一种基于岩石峰前能量演化及峰后侧向变形特征的岩石脆性评价方法,建立岩石峰前脆性指标B pre及峰后脆性指标B post,将两者之积作为岩石脆性评价指标B_(m)。为验证脆性评价指标的合理性,选取凉山州某铁矿矿山扩能工程露天采场边坡发育的玢岩、辉长岩及花岗岩为研究对象,开展不同岩石及不同围压条件下的三轴压缩试验;采用已有的脆性评价方法B_(15)~B_(18)、B_(23)与本文所提的岩石脆性评价指标B_(m)对试样的脆性特征进行验证对比,结果表明:(1)采用脆性指标B_(m)能够较好地评定不同种类岩石的脆性特征,B_(m)与岩石脆性呈负相关,即脆性评价指标B_(m)越大,岩石脆性程度越高;(2)脆性指标B_(m)较好地验证了围压对岩石脆性特征的影响,随着围压的增大,岩石脆性程度降低。本文所提出的脆性评价方法丰富和完善了岩石室内脆性评价体系,具有一定的理论意义及工程实用价值。
In this paper,a rock brittleness evaluation method based on pre-peak energy evolution and post-peak lateral deformation characteristics of rock is proposed so as to achieve quantitative characterization of pre-peak and post-peak brittleness characteristics of rock.Accordingly,the pre-peak brittleness index B pre and post-peak brittleness index B post are established,and the product of the two is taken as the rock brittleness evaluation index B_(m).In order to verify the rationality of brittleness evaluation index,the porphyrite,gabbro and granite developed in the open pit slope of an iron mine expansion project in Liangshan Prefecture are selected as the research objects,and triaxial compression tests are carried out under different rocks and different confining pressure conditions.Existing brittleness evaluation methods B_(15)~B_(18) and B_(23) are used to verify and compare the brittleness characteristics of the samples with the rock brittleness evaluation index B_(m) proposed in this paper.The results show that the brittleness characteristics of different kinds of rocks can be well evaluated by brittleness index B_(m),and there is a negative correlation between B_(m) and brittleness of rocks,that is,the greater the brittleness evaluation index B_(m),the higher the brittleness of rocks.Meanwhile,brittleness index B_(m) well verifies the influence of confining pressure on the brittleness characteristics of rocks.With the increase of confining pressure,the brittleness degree of rocks decreases.It shows that the brittleness evaluation method proposed in this paper has enriched and improved the indoor brittleness evaluation system of rocks,and had certain theoretical significance and engineering practical value.
作者
宋昊
夏敏
任光明
SONG Hao;XIA Min;REN Guangming(State Key Laboratory of Geohazard Prevention and Environment Protection,Chengdu University of Technology,Chengdu 610059,China)
出处
《成都理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2023年第6期723-733,共11页
Journal of Chengdu University of Technology: Science & Technology Edition
基金
国家自然科学基金青年科学基金项目(41907246)。
关键词
岩石脆性指标
应力-应变曲线
能量演化
侧向变形
rock brittleness index
stress-strain curve
energy evolution
lateral deformation
