考虑损伤与残余强度的岩石类材料本构模型及其应用研究
发布时间:2018-07-05 20:53
本文选题:岩石类材料 + 损伤 ; 参考:《南京理工大学》2015年硕士论文
【摘要】:本文基于连续损伤和统计强度理论,从岩石内部含有大量随机分布微缺陷的特点出发,将岩石损伤参量的数学模型重新定义为修正的Harris函数,采用Hoek-Brown准则作为岩石微元统计分布变量,建立三轴压缩状态下的岩石损伤模型。根据单轴压缩试验及统计损伤理论,由胡克定律修改单轴压缩条件下Hoek-Brown准则的表达式,建立了针对单轴压缩状态下的岩石损伤本构模型。通过研究单轴压缩和拉伸条件下岩石力学特征的规律与相似性,从全新的角度提出一种建立岩石单轴拉伸损伤模型的方法。三种受力状态的损伤本构模型都通过引入损伤系数J,来表征岩石的渐进破坏特性,也能在一定程度上反映这种准脆性材料的性质。量化的GSI围岩分级系统通过引入节理条件系数JC和岩块体积Vb,对GSI系统进行量化取值,其与新版Hoek-Brown准则相结合,可以估算出节理岩体的峰值强度以及变形模量。联系甘肃北山某区实际,采用残余GSI量化评价法,通过折减峰值地质强度指标得到残余地质强度指标GSIr,从而计算出残余强度参数,最后确定了该区的力学参数。通过采用FORTRAN语言开发完成的USDFLD用户子程序,提取材料积分点处的最小主应力σ3并定义为场变量,从而实现了材料应力-应变关系随围压的变化。针对室内岩石力学试验,利用ABAQUS对模型单元进行有限元计算并验证了该方法的可行性。最后结合由量化GSI系统确定的岩体力学参数,对深部巷道围岩的开挖响应进行模拟分析,其结果对实际工程具有一定的指导意义。
[Abstract]:Based on the theory of continuous damage and statistical strength, the mathematical model of rock damage parameters is redefined as a modified Harris function from the point of view of the fact that there are a large number of randomly distributed microdefects in rock. The damage model of rock under triaxial compression is established by using Hoek-Brown criterion as the statistical distribution variable of rock microelements. According to uniaxial compression test and statistical damage theory, the Hoek-Brown criterion under uniaxial compression is modified by Hooke's law, and the constitutive model of rock damage under uniaxial compression is established. By studying the regularity and similarity of rock mechanical characteristics under uniaxial compression and tensile conditions, a new method to establish uniaxial tensile damage model of rock is proposed from a new point of view. The damage constitutive models of three kinds of stress states can characterize the progressive failure characteristics of rock by introducing damage coefficient J, and can also reflect the properties of this kind of quasi brittle material to a certain extent. By introducing the joint condition factor JC and the volume of rock mass Vb, the quantitative GSI surrounding rock classification system can estimate the peak strength and deformation modulus of jointed rock mass by combining it with the new Hoek-Brown criterion. According to the practice of a certain area in Beishan, Gansu Province, residual GSI quantitative evaluation method is used to obtain the residual geological strength index GSIrby reducing the index of peak geological strength, thus calculating the parameters of residual strength, and finally determining the mechanical parameters of the area. By using the user subprogram of USDFLD developed in FORTRAN language, the minimum principal stress 蟽 3 at the material integration point is extracted and defined as a field variable, so that the stress-strain relationship of the material varies with the confining pressure. The finite element calculation of the model element is carried out by Abaqus and the feasibility of the method is verified. Finally, combined with the mechanical parameters of rock mass determined by the quantitative GSI system, the excavation response of deep roadway surrounding rock is simulated and analyzed. The results have certain guiding significance for practical engineering.
【学位授予单位】:南京理工大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:TU45
【参考文献】
相关期刊论文 前5条
1 韩凤山;;节理化岩体强度与力学参数估计的地质强度指标GSI法[J];大连大学学报;2007年06期
2 王驹;;高放废物地质处置:进展与挑战[J];中国工程科学;2008年03期
3 孙卫军;周维垣;;裂隙岩体弹塑性-损伤本构模型[J];岩石力学与工程学报;1990年02期
4 曹文贵,赵明华,唐学军;岩石破裂过程的统计损伤模拟研究[J];岩土工程学报;2003年02期
5 王宇;李晓;李守定;侯文诗;吴雨松;张搏;;一种确定节理岩体残余强度参数方法的探讨[J];岩石力学与工程学报;2013年08期
相关会议论文 前1条
1 赵宏刚;王驹;刘月妙;宗自华;;处置库硐室开挖稳定性分析——甘肃北山为例[A];第二届废物地下处置学术研讨会论文集[C];2008年
,本文编号:2101747
本文链接:https://www.wllwen.com/kejilunwen/diqiudizhi/2101747.html