任意多裂隙岩体损伤模型研究
发布时间：2018-07-20 12:47
【摘要】：目前对裂隙岩体的损伤模型研究主要集中在以下两个方面:一是以仅考虑裂隙长度、倾角及间排距等几何性质的几何损伤理论;二是同时考虑裂隙几何参数及力学参数的损伤理论。本文在对周期性裂隙的岩体力学特性进行研究的基础上,更进一步地研究了任意非贯通裂隙对岩体力学特性的影响,得到的主要成果如下:(1)从含单条非贯通裂隙的岩体入手,从能量角度出发推导出了由单条裂隙引起的损伤变量计算公式,通过考虑裂隙间的相互作用,求解出了单排及多排非贯通平行裂隙的应力强度因子和损伤变量。应用平面弹性力学,给出了任意多裂隙的应力强度因子的计算公式,并得到多条裂隙相互作用关系式。(2)建立多裂隙的应力强度因子算例,多条裂隙的相互作用与其几何相对位置及倾角有关。两条裂隙的外侧尖端A、D的应力强度因子受相互作用影响较内侧尖端B、C的小。平行裂隙间的相互影响与裂隙间距有关,且随着裂隙间距的增大,计算所得的应力强度因子值都趋于不考虑裂隙相互影响时的应力强度因子值。(3)根据裂隙的相对几何位置和倾角变化,进行不同叠加后的应力场可分别产生增强与减弱两种效应,当相邻裂隙尖端处于加强区时,其应力强度因子将会变大,反之变小。(4)在压剪应力作用下,两条裂隙间距越小,裂隙尖端的应力场越复杂,裂隙间的相互作用就越强,这说明在同一外部条件下,多裂隙岩体更容易发生由裂纹引起的破坏。(5)建立了两条任意非贯通裂隙的岩体损伤模型,并获得了两条任意非贯通裂隙模型的损伤变量。将两条任意非贯通裂隙模型设定为两条垂直距离为零的平行裂隙的情况,计算出的损伤变量与已知文献的计算结果进行对比,结果较为吻合,说明了本模型的合理性。
[Abstract]:At present, the research on damage model of fractured rock mass is mainly focused on the following two aspects: one is based on the geometric damage theory which only considers the geometric properties of crack length, dip angle and spacing; The second is the damage theory which considers the geometric and mechanical parameters of fracture at the same time. Based on the study of the mechanical properties of rock mass with periodic fractures, this paper further studies the influence of any non-penetrating fracture on the mechanical properties of rock mass. The main results obtained are as follows: (1) starting with the rock mass with single non-perforated fracture, The formula of damage variable caused by single fracture is derived from the angle of energy. The stress intensity factor and damage variable of single row and multiple rows of non-penetrating parallel fractures are calculated by considering the interaction between fractures. In this paper, the formula of stress intensity factor of arbitrary multiple fractures is given by using plane elasticity, and the formula of interaction between multiple fractures is obtained. (2) an example of stress intensity factor of multiple fractures is established. The interaction of multiple fractures is related to their geometric relative position and inclination. The stress intensity factor of the lateral tip of the two fractures is less affected by the interaction than that of the inner tip of BHOC. The interaction between parallel fractures is related to the spacing of fractures, and with the increase of the spacing of fractures, The calculated values of the stress intensity factors tend to be the values of the stress intensity factors without considering the interaction of fractures. (3) according to the relative geometric position and the dip angle of the fractures, the stress fields after different stacking can produce two kinds of effects, which are strengthening and weakening, respectively. When the adjacent crack tip is in the strengthening zone, the stress intensity factor will become larger, and vice versa. (4) the smaller the spacing between the two fractures, the more complex the stress field at the crack tip, and the stronger the interaction between the fractures. This shows that the damage caused by cracks is more likely to occur in multifissured rock mass under the same external conditions. (5) two damage models of arbitrary non-penetrating fractures are established and the damage variables of two arbitrary non-penetrating fracture models are obtained. In this paper, two arbitrary nonpenetrating fracture models are set to two parallel fractures with zero vertical distance. The calculated damage variables are compared with the results of known literatures. The results show that the model is reasonable.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45
，
本文编号：2133560
[Abstract]:At present, the research on damage model of fractured rock mass is mainly focused on the following two aspects: one is based on the geometric damage theory which only considers the geometric properties of crack length, dip angle and spacing; The second is the damage theory which considers the geometric and mechanical parameters of fracture at the same time. Based on the study of the mechanical properties of rock mass with periodic fractures, this paper further studies the influence of any non-penetrating fracture on the mechanical properties of rock mass. The main results obtained are as follows: (1) starting with the rock mass with single non-perforated fracture, The formula of damage variable caused by single fracture is derived from the angle of energy. The stress intensity factor and damage variable of single row and multiple rows of non-penetrating parallel fractures are calculated by considering the interaction between fractures. In this paper, the formula of stress intensity factor of arbitrary multiple fractures is given by using plane elasticity, and the formula of interaction between multiple fractures is obtained. (2) an example of stress intensity factor of multiple fractures is established. The interaction of multiple fractures is related to their geometric relative position and inclination. The stress intensity factor of the lateral tip of the two fractures is less affected by the interaction than that of the inner tip of BHOC. The interaction between parallel fractures is related to the spacing of fractures, and with the increase of the spacing of fractures, The calculated values of the stress intensity factors tend to be the values of the stress intensity factors without considering the interaction of fractures. (3) according to the relative geometric position and the dip angle of the fractures, the stress fields after different stacking can produce two kinds of effects, which are strengthening and weakening, respectively. When the adjacent crack tip is in the strengthening zone, the stress intensity factor will become larger, and vice versa. (4) the smaller the spacing between the two fractures, the more complex the stress field at the crack tip, and the stronger the interaction between the fractures. This shows that the damage caused by cracks is more likely to occur in multifissured rock mass under the same external conditions. (5) two damage models of arbitrary non-penetrating fractures are established and the damage variables of two arbitrary non-penetrating fracture models are obtained. In this paper, two arbitrary nonpenetrating fracture models are set to two parallel fractures with zero vertical distance. The calculated damage variables are compared with the results of known literatures. The results show that the model is reasonable.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU45
，
本文编号：2133560
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