基于侧向变形的花岗岩脆性特征评价新方法  

A new method to evaluate the brittleness of granite based on lateral deformation

作　　者：杨景祥 冯韬 曾亚武[1] 明冬雨 朱泽奇[3] YANG Jingxiang;FENG Tao;ZENG Yawu;MING Dongyu;ZHU Zeqi(School of Civil and Architectural Engineering,Wuhan University,Wuhan 430072,China;Central and Southern China Municipal Engineering Design and Research Institute Co.,Ltd.,Wuhan 430010,China;State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)

机构地区：[1]武汉大学土木建筑工程学院,湖北武汉430072 [2]中国市政工程中南设计研究总院有限公司,湖北武汉430010 [3]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《武汉大学学报（工学版）》2022年第8期786-792,共7页Engineering Journal of Wuhan University

基　　金：国家自然科学基金项目(编号:41772308,51279202)。

摘　　要：基于花岗岩三轴试验侧向应力-应变曲线,提出一种改进的岩石脆性评价参数。以大岗山水电厂房区花岗岩为例,采用6种不同围压开展了岩石三轴压缩试验,分析了花岗岩的侧向变形特征。试验结果表明:岩样表现出典型的脆塑性特征,随着围压的增大,岩样峰值轴向应变增大,峰值径向应变变化较小。据此进一步提出了基于轴向偏应力与侧向应变的岩石脆性评价参数,通过与其他4种脆性参数进行对比发现,利用侧向变形特征对岩石脆性进行描述的参数模型物理意义明确且更为直观简便,能够从脆性变化规律和脆性值大小2个方面综合反映岩样的脆性特征。Based on the lateral stress-strain curve of granite triaxial test, an improved rock brittleness evaluation parameter is proposed. Six groups of triaxial compression test are carried out to analyze the lateral deformation characteristics of granite in Dagangshan Hydropower Plant. The results show that the rock samples have typical brittle plastic characteristics. The peak value of axial deformation increases gradually with the increase of the confining pressure, while the lateral deformation almost remains unchanged. In addition, a new evaluation method of rock brittleness based on the post-peak axial stress and lateral strain is proposed. The rock brittleness evaluation parameter model based on the axial deviatoric stress and the lateral strain is proposed and compared with other four kinds of brittleness parameter models. It is found that the parameter model describing rock brittleness based on lateral deformation characteristics has clear physical significance, and is more intuitive and simple. The parameter model proposed can reflect the brittleness characteristics of rock samples comprehensively from two aspects such as brittleness change law and brittleness value.

关 键 词：花岗岩 脆性评价 侧向变形 三轴压缩试验 

分 类 号：TU45[建筑科学—岩土工程]