工程岩体渐进破坏的广义粒子动力学数值模拟

发布时间：2018-03-10 19:43

本文选题：配点无网格法　切入点：GPD法　出处：《重庆大学》2015年博士论文　论文类型：学位论文

【摘要】：复杂受力条件下各类大型岩体工程的稳定性历来备受关注,无网格法作为数值分析的一大类方法,在描述工程结构体渐进破坏,模拟岩石材料的裂纹扩展方面具有优势,可用于判断工程的稳定性,是目前岩土工程数值分析方法领域的一个研究热点。本文基于学者对无网格算法的已有研究,提出应用于岩石工程领域的广义粒子动力学法(General Particle Dynamics,GPD法)。研究工作主要有以下几个方面:①提出适用于岩石类材料渐进破坏模拟的无网格GPD法。方法基于连续介质守恒方程,用威布尔统计学方法描述岩石不均质特点,采用岩石本构方程和岩石力学的参数,沿用无网格配点法中光滑粒子流体动力学(Smoothed Particle Hydrodynamics,SPH)方法的离散思想,引入岩石屈服准则等,使得GPD法能较好的模拟弹脆性岩石材料的裂纹扩展。②无网格GPD法作为动态数值模拟方法,用于准静态力学模型。基于岩石单轴压缩GPD模型,模拟二维和三维岩样中裂纹的扩展,同时考察岩样模型的应力场、应变场、破坏模式等,模拟结果与单轴压缩实验结论进行对比,考察GPD程序在准静态试验中的可靠性。③无网格GPD法用于简单边坡渐进破坏数值模拟。将强度折减法(Shear strength reduction method,SRM)融入GPD法,通过临界强度折减系数(Shear strength reduction factor,SRF)定义了配点型无网格算法中边坡的安全系数,用于评价岩质边坡的稳定性。④无网格GPD法用于混凝土抗滑桩加强型简单边坡渐进破坏的数值模拟。将抗滑桩加固边坡看做抗滑桩和岩质边坡两种材料耦合作用的模型,在GPD法中融入耦合边界条件和边界粒子作用方式,在无网格法自适应的特点下,可实现对抗滑桩加固岩质边坡稳定性的评价。⑤弹塑性GPD法的建立。将考虑剪胀性的弹塑性理论引入GPD法,同时将隧道模型简化为弹塑性圆形隧道模型,采用GPD法从塑性角度评估、描述围岩稳定性。⑥建立考虑动态特征的GPD法,并应用于岩爆模型。将适用岩石“高地应力+动态扰动”力学状态的含率效应的HJC强度模型引入GPD法,用于判断隧洞中岩石GPD粒子屈服,在含不同预置裂纹的圆形隧道模型中,实现GPD法对深部围岩岩爆的模拟。⑦以锦屏二级水电站隧道为研究背景,采用理论分析、GPD数值模拟方法对引水隧洞、辅助隧洞的稳定性进行了研究。通过GPD法对锦屏二级水电站隧道的力学场量、围岩渐进破坏、围岩坍塌等进行精细模拟,尝试GPD法用于预测工程岩爆发生的位置和强度。
[Abstract]:The stability of large rock mass engineering under complex stress conditions has always been concerned. As a large class of numerical analysis methods, meshless method has advantages in describing progressive failure of engineering structures and simulating crack growth of rock materials. It is a hot research topic in the field of numerical analysis of geotechnical engineering, which can be used to judge the stability of engineering. In this paper, a generalized particle dynamics method for rock engineering is presented. There are several aspects in the research work: 1. A meshless GPD method for progressive failure simulation of rock materials is proposed. The method is based on the conservation equation of continuum medium. The characteristics of rock heterogeneity are described by Weibull statistical method. The constitutive equation of rock and the parameters of rock mechanics are used. The discrete idea of smooth particle hydrodynamics (Smoothed Particle hydrodynamics) method and rock yield criterion are adopted in the meshless collocation method. The GPD method can be used to simulate the crack propagation of elastic-brittle rock materials. 2. The meshless GPD method is used as a dynamic numerical simulation method for quasi static mechanical model. Based on the uniaxial compression GPD model of rock, the crack propagation in two and three dimensional rock samples is simulated. At the same time, the stress field, strain field and failure mode of rock sample model are investigated. The simulation results are compared with the results of uniaxial compression experiment. The reliability of GPD code in quasi static test was investigated. 3 meshless GPD method was applied to numerical simulation of simple slope progressive failure. The strength reduction method Shear strength reduction method SRM was incorporated into GPD method. The safety factor of slope in the meshless collocation algorithm is defined by the critical strength reduction coefficient (Shear strength reduction factor-SRF). In order to evaluate the stability of rock slope, the method of .4 meshless GPD is used to simulate the progressive failure of reinforced simple slope with concrete anti-slide pile. The reinforcement of slope with anti-slide pile is regarded as a coupling model of two kinds of materials, that is, anti-slide pile and rock slope. The coupled boundary condition and boundary particle interaction mode are incorporated in the GPD method, and the meshless method is adaptive. It can be realized to evaluate the stability of rock slope strengthened by anti-slide pile. The elastoplastic theory considering shear dilatancy is introduced into GPD method, and the tunnel model is simplified as an elastic-plastic circular tunnel model. The GPD method is used to evaluate the stability of surrounding rock from the plastic point of view. The GPD method considering the dynamic characteristics is established and applied to the rock burst model. The HJC strength model suitable for the mechanical state of "dynamic disturbance of high in-situ stress" is introduced into the GPD method. In order to judge the yield of rock GPD particles in tunnel, in the circular tunnel model with different preset cracks, the simulation of rock burst in deep surrounding rock by GPD method is realized. In this paper, the stability of diversion tunnel and auxiliary tunnel is studied by means of theoretical analysis and GPD numerical simulation method. The mechanical field, progressive failure of surrounding rock and collapse of surrounding rock are simulated by GPD method. This paper attempts to use GPD method to predict the location and strength of engineering rockburst.
【学位授予单位】：重庆大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TU45

【相似文献】