裂隙岩体中弹性波传播特性试验及宏细观损伤本构模型研究  

Characteristics of elastic wave propagation in jointed rock mass and development of constitutive model by coupling macroscopic and mesoscopic damage

作　　者：赵航[1,2] 李新平[1,2] 罗忆[1] 董千[2] 黄俊红[2] ZHAO Hang LI Xin-ping LUO Yi DONG Qian HUANG Jun-hong(Hubei Key Laboratory of Road-Bridge and Structure Engineering, Wuhan University of Technology, Wuhan, Hubei 430070, China School of Civil Engineering and Architecture, Wuhan University of Technology, Wuhan, Hubei 430070, China)

机构地区：[1]武汉理工大学道路桥梁与结构工程湖北省重点实验室,湖北武汉430070 [2]武汉理工大学土木工程与建筑学院,湖北武汉430070

出　　处：《岩土力学》2017年第10期2939-2948,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金面上项目(No.51274157);国家自然科学基金青年基金项目(No.51309183)~~

摘　　要：以不同加载方式下裂隙岩体中弹性波传播特性试验为基础,首先通过对比试验中弹性波波速、波幅与岩体宏观损伤的关系,给出了采用弹性波波幅来表征的裂隙岩体宏观损伤变量;其次利用统计强度理论定义了岩石的细观损伤变量,并基于连续损伤理论建立了宏、细观裂隙耦合的裂隙岩体损伤本构模型;最后结合试验数据对该模型进行了验证与分析。研究表明:完整岩体中细观裂隙的起裂和扩展对岩体中传播弹性波的波幅和波速的影响较小,而裂隙岩体中宏观裂隙的张开和闭合对弹性波波幅和波速的影响较大。裂隙岩体在外力作用下时,弹性波波速和波幅的变化规律类似,相较于弹性波波速,弹性波波幅对裂隙岩体宏观损伤的变化表现的更敏感,可用来定义裂隙岩体的宏观损伤变量。不同加载方式下裂隙岩体的损伤特性与宏、细观裂隙以及其所处的应力状态相关,基于宏、细观裂隙耦合的裂隙岩体损伤本构模型可以较好地反映不同加载方式下裂隙岩体的损伤力学特性。在三轴压缩试验中,宏观裂隙对岩体轴向压应力方向上损伤的影响主要体现在试验的中后期阶段,在三轴拉压试验中,宏观裂隙对岩体轴向拉应力方向上损伤的影响贯穿于试验全过程中。In this paper, experiments were conducted on jointed rock mass to study characteristics of elastic wave propagation under different loading conditions. Firstly, by comparing the amplitude and velocity of the elastic wave with the damage degree of rock mass, the macroscopic damage variable of jointed rock mass were characterized by the amplitude of elastic wave. Then, the mesoscopic damage variable was defined through the statistical strength theory. Afterwards, on the basis of the continuous damage theory, a constitutive model by coupling macroscopic and mesoscopic joints was established. Finally, the model was verified and analyzed by combining experimental data. The study shows that, for the intact rock, initiation and propagation of mesoscopic cracks have less effect on the amplitude and velocity of elastic wave. However, for jointed rock mass, the opening and closing of macroscopic joints have a great effect on them. The amplitude and velocity of elastic wave have similar variation law when jointed rock mass is subjected to external force. In comparison with the elastic wave velocity, the attenuation of elastic wave amplitude is sensitive to the changes of the damage degree of jointed rock mass. Thus, it can be used to characterize the macroscopic damage variable of rock mass. Under different loading methods, the damage characteristic of jointed rock mass is determined by macroscopic and mesoscopic joints and its stress state. Therefore, the constitutive model can well reflect damage mechanical properties of jointed rock mass under different stress paths. In triaxial compression tests, the effect of macroscopic joints on the damage of rock mass in the direction of axial compressive stress plays a significant role in the middle and later period of the experiment. While in triaxial tension and compression tests, the macroscopic joint maintains its effect on the damage of rock mass in the direction of axial tensile stress within the whole process of the experiment.

关 键 词：裂隙岩体 细观裂隙 宏观裂隙 损伤变量 本构模型 

分 类 号：TU443[建筑科学—岩土工程]