基于节理岩体损伤本构模型的FLAC3D二次开发及应用

发布时间：2018-06-06 12:26

本文选题：细观缺陷 + 宏观缺陷　；参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：自然界中的岩体不但含有节理、裂隙等宏观缺陷,而且也含有微孔洞、微裂纹等细观缺陷。在进行岩体的损伤分析时,目前的学者多是把两种缺陷分割开来进行考虑,显然这与实际情况是不符的。节理、裂隙等宏观缺陷是由微裂隙、微孔洞等细观缺陷发展演化而来,宏观缺陷的扩展也会产生新的细观缺陷,两种缺陷存在着复杂的相互作用。这就要求我们提出一种能同时反映两种不同尺度缺陷的本构模型。本文以此为出发点开展了以下研究:(1)基于拉应变准则和Weibull分布建立了只考虑细观损伤的岩体损伤本构模型;综合考虑岩体中节理的长度、倾角、条数等物理参数及节理的内摩擦角、节理粘聚力等力学参数建立了含节理等宏观损伤的岩体本构模型;根据Lemaitre应变等效假设,对两种不同类型的损伤的损伤变量进行耦合,得出综合考虑宏细观损伤的耦合损伤本构模型。(2)以岩土模拟软件FLAC3D为基础,用VC++语言对自定义本构模型进行二次开发,生成可供FLAC3D调用的动态链接库文件。自定义本构模型开发过程主要包括基类成员函数的定义、模型的注册、模型与FLAC3D之间的数据传递以及模型状态指示器,最后对自定义本构模型进行加载和运行。(3)在FLAC3D中进行了一个岩石试件的单轴压缩数值试验。当模拟试件中含单条节理时,得出试件的自定义本构模型的应力应变曲线并与理论曲线和摩尔-库伦本构模型的模拟曲线进行对比,验证了自定义本构模型的合理性;当模拟试件含单组节理时,分别改变节理的长度、倾角、条数、内摩擦角,验证这些参数的改变对岩体试件的强度的影响。(4)最后结合一个隧道开挖的工程实例,介绍了隧道的基本情况,建立隧道开挖模型,对隧道开挖过程中的沉降变形进行监测并与实际的监测数据进行对比,进一步验证自定义本构模型的正确性。
[Abstract]:Rock mass in nature contains not only macroscopic defects such as joints and fissures, but also micropores and microcracks. In the damage analysis of rock mass, most of the present scholars consider the two kinds of defects, which is obviously not in accordance with the actual situation. The macroscopical defects such as joints and fissures evolved from the development of microcracks, microvoids and so on. The expansion of macroscopic defects will also produce new meso-defects, and the two kinds of defects have complex interaction. This requires us to propose a constitutive model that can simultaneously reflect two different scales of defects. Based on the tensile strain criterion and Weibull distribution, the constitutive model of rock mass damage with only mesoscopic damage is established, and the length and inclination of joints in rock mass are considered synthetically. The constitutive model of rock mass with macroscopic damage such as joints, such as physical parameters such as strip number, internal friction angle of joints, cohesion of joints and other mechanical parameters, is established, and two kinds of damage variables are coupled according to the Lemaitre strain equivalence hypothesis. It is concluded that the coupling damage constitutive model. (2) based on the geotechnical simulation software FLAC3D, the self-defined constitutive model is redeveloped with VC language to generate the dynamic link library file which can be called by FLAC3D. The development process of custom constitutive model mainly includes the definition of base class member function, the registration of model, the data transfer between model and FLAC3D, and the indicator of model state. Finally, a uniaxial compression numerical test of a rock specimen was carried out in FLAC3D by loading and running a self-defined constitutive model. When a single joint is included in the simulated specimen, the stress-strain curve of the self-defined constitutive model of the specimen is obtained and compared with the theoretical curve and the simulation curve of the Mole-Coulomb constitutive model, which verifies the rationality of the self-defined constitutive model. When the simulated specimen contains a single set of joints, the length, inclination, number and angle of internal friction of the joints are changed, respectively, to verify the influence of the change of these parameters on the strength of the rock mass specimen. This paper introduces the basic situation of the tunnel, establishes the tunnel excavation model, monitors the settlement and deformation during the tunnel excavation and compares with the actual monitoring data, further validates the correctness of the self-defined constitutive model.
【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】：2015
【分类号】：TU45

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