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论述了地质力学这一我国独立建立的地质学科形成的背景、基本特征、主要成就和存在问题, 指出:地质力学是在地质学三大论战, 特别是大陆漂移学说影响下, 独辟蹊径提出的; 地质力学有4个基本特征, 即3个立论依据, 9个基本概念, 7个研究步骤, 4个基本观点(本质的、联系的、发展的和实践的)。全面论述了地质力学10个理论方面、5个技术方法和5个生产实践方面的突出成就。地质力学存在的突出问题:本质上被裹挟于"固定论"泥潭中, 在认识新发现和接纳新观念上裹足不前; 古构造时期鉴别上存在重大误区, 过分强调了造山带的"长期继承活动"; 深部地质和全球海洋地质研究十分薄弱等。因此, 解放思想、与时俱进和走向全球是它当前3个紧迫任务。 相似文献
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The Galerkin finite-element discretization of the force balance equation typically leads to large linear systems for geomechanical problems with realistic dimensions. In iteratively coupled flow and geomechanics modeling, a large linear system is solved at every timestep often multiple times during coupling iterations. The iterative solution of the linear system stemming from the poroelasticity equations constitutes the most time-consuming and memory-intensive component of coupled modeling. Block Jacobi, LSOR, and Incomplete LU factorization are popular preconditioning techniques used for accelerating the iterative solution of the poroelasticity linear systems. However, the need for more effective, efficient, and robust iterative solution techniques still remains especially for large coupled modeling problems requiring the solution of the poroelasticity system for a large number of timesteps. We developed a supercoarsening multigrid method (SCMG) which can be multiplicatively combined with commonly used preconditioning techniques. SCMG has been tested on a variety of coupled flow and geomechanics problems involving single-phase depletion and multiphase displacement of in-situ hydrocarbons, CO2 injection, and extreme material property contrasts. Our analysis indicates that the SCMG consistently improves the convergence properties of the linear systems arising from the poroelasticity equations, and thus, accelerates the coupled simulations for all cases subject to investigation. The joint utilization of the two-level SCMG with the ILU1 preconditioner emerges as the most optimal preconditioning/iterative solution strategy in a great majority of the problems evaluated in this work. The BiCGSTAB iterative solver converges more rapidly compared to PCG in a number of test cases, in which various SCMG-accelerated preconditioning strategies are applied to both iterators. 相似文献
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An understanding of the fracture mechanics of geomaterials is important for the solution of many problems in geomechanics. One of the most important material properties involved in fracture mechanics is the fracture toughness, KIc. The short-rod test configuration proposed by Barker1 has significant potential for becoming a standard test for fracture toughness determination in geomechanics. The purpose of this brief is to examine the application potential of the short-rod test for geomechanics problems. 相似文献
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Boris Jeremi&#x; Gerik Scheuermann Jan Frey Zhaohui Yang Bernd Hamann Kenneth I. Joy Hans Hagen 《国际地质力学数值与分析法杂志》2002,26(10):925-944
We present a novel technique for visualizing tensors in three dimensional (3D) space. Of particular interest is the visualization of stress tensors resulting from 3D numerical simulations in computational geomechanics. To this end we present three different approaches to visualizing tensors in 3D space, namely hedgehogs, hyperstreamlines and hyperstreamsurfaces. We also present a number of examples related to stress distributions in 3D solids subjected to single and load couples. In addition, we present stress visualizations resulting from single‐pile and pile‐group computations. The main objective of this work is to investigate various techniques for visualizing general Cartesian tensors of rank 2 and it's application to geomechanics problems. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
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A version of the Particle Finite Element Method applicable to geomechanics applications is presented. A simple rigid-plastic material model is adopted and the governing equations are cast in terms of a variational principle which facilitates a straightforward solution via mathematical programming techniques. In addition, frictional contact between rigid and deformable solids is accounted for using an approach previously developed for discrete element simulations. The capabilities of the scheme is demonstrated on a range of quasi-static and dynamic problems involving very large deformations. 相似文献
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地震导致山体变形破裂是一个复杂的演化过程,文中通过一些典型实例的地质分析,总结归纳了高地震烈度区山体变形破裂失稳有一定代表性的倾外层状体斜坡滑坡型、高陡块(层)状体斜坡崩塌型、软弱基座体斜坡滑坡型等3种典型性地质力学模式。自主创新研制、设计、探索了一套振动条件下地质力学模拟试验的设备模型和方法,并对3种典型性地质力学模型进行机制模拟试验。通过变形破裂演化过程模拟再现试验,从中揭示出一些振动条件下变形破裂的典型迹象和重要证据,充分再现了典型地震失稳机制的形成条件、相关性因素以及演化规律,为进一步研究分析提供科学可靠的试验数据和证据。 相似文献
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Numerical modelling as an efficient method is widely employed in various fields of science and engineering. In rock mechanics and geomechanics, considerable progress has been made in numerical simulation on nonlinear and discontinuum problems. However, there is a tendency in this field that the theoretical framework for nonlinear and discontinuum problems becomes more and more complicated and sometimes becomes less practicable. This paper gives a brief introduction to a newly developed numerical code, RFPA2D (rock failure process analysis), which is mathematically a linear and continuum mechanics method for numerically processing nonlinear and discontinuum mechanics problems in rock failure. Although it is simple comparing with other numerical methods for nonlinear and discontinuum problems. It allows one to model the observed evolution of the progressive failure leading to collapse in brittle rocks. An important conclusion from the simulation results is that the microscale heterogeneity is the source of macroscale nonlinearity. Examples showing the potential applications are given in this paper. It can be seen that the RFPA2D has a unique ability to reveal the evolutionary nature of the fracture phenomenon from microfracture scale to global failure, and the great potential exists in modelling mining induced rockbursts and stability of underground openings in greath depth. The capabilities to handle dilation, self-induced faults or even block movement and rotation should also attract applications in the fields of geomechanics as well as rock mechanics. 相似文献
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Results of numerical analyses of boundary value problems in geomechanics include output of three‐dimensional stress and strain states. Two‐dimensional plots of stress–stress or stress–strain quantities, often used to represent such output, do not fully communicate the evolution of stress and strain states. This paper describes the use of glyphs and hyperstreamlines for the visual representation of three dimensional stress and strain tensors in geomechanics applications. Glyphs can be used to represent principal stress states as well as normal stresses at a point. The application of these glyphs is extended in this paper to represent strain states. The paper introduces a new glyph, called HWY glyph for the representation of shear tensor components. A load step‐based hyperstreamline is developed to show the evolution of a stress or strain tensor under a general state of loading. The evolution of stress–strain states from simulated laboratory tests and a general boundary value problem of a deep braced excavation are represented using these advanced visual techniques. These visual representations facilitate the understanding of complex multidimensional stress–strain soil constitutive relationships. The visual objects introduced in this paper can be applied to stress and strain tensors from general boundary value problems. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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地质力学磁力模型试验利用电磁力（场）模拟重力（场）的原理研究地质力学工程问题,采用的相似材料由铁磁材料与岩土体混合而成。铁磁材料在磁场中的受力方向和大小与所处空间的磁通密度梯度的大小和方向有关,为了模拟均匀的重力场,需要得到在一定空间范围内磁通密度梯度大小相同、方向单一的磁场。根据电磁学基本原理,构建了3种磁路形式以获得磁通密度梯度相对均匀的磁场,对磁力模型试验相似材料进行加载。对比3种磁路,在最佳试验区内开放式磁路对磁场的利用率更高,所以在电流相同条件下等到的磁通密度梯度的量值也更大。与另两种磁路形式相比,尽管半开放式磁路在重量和工作效率上的性能不及开放式和封闭式磁路,但其最佳试验空间的磁通密度梯度的均匀性最好,误差在5%以内,半开放式磁路可以作为地质力学磁力模型试验的磁场发生装置。 相似文献
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The method of smoothed particle hydrodynamics (SPH) has recently been applied to computational geomechanics and has been shown to be a powerful alternative to the standard numerical method, that is, the finite element method, for handling large deformation and post‐failure of geomaterials. However, very few studies apply the SPH method to model saturated or submerged soil problems. Our recent studies of this matter revealed that significant errors may be made if the gradient of the pore‐water pressure is handled using the standard SPH formulation. To overcome this problem and to enhance the SPH applications to computational geomechanics, this article proposes a general SPH formulation, which can be applied straightforwardly to dry and saturated soils. For simplicity, the current work assumes hydrostatic pore‐water pressure. It is shown that the proposed formulation can remove the numerical error mentioned earlier. Moreover, this formulation automatically satisfies the dynamic boundary conditions at a submerged ground surface, thereby saving computational cost. Discussions on the applications of the standard and new SPH formulations are also given through some numerical tests. Furthermore, techniques to obtain the correct SPH solution are also proposed and discussed throughout. As an application of the proposed method, the effect of the dilatancy angle on the failure mechanism of a two‐sided embankment subjected to a high groundwater table is presented and compared with that of other solutions. Finally, the proposed formulation can be considered a basic formulation for further developments of SPH for saturated soils. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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数值流形方法（NMM）的最大优势在于可以统一地处理岩土力学中的连续和非连续变形问题。它在求解断裂力学问题时无需强制裂纹与数学网格保持一致,非常适合应用于岩土工程中由连续到非连续的破坏过程模拟。在裂纹扩展过程中,裂纹与数学网格的相对位置将会是任意的,如裂纹尖端可能落在网格内部、网格节点上或网格边上等。因此,对同一条裂纹,通过旋转和移动数学网格构造了它们之间的这种相对位置关系以及一些可能对计算结果产生影响的极端情况,并以应力强度因子作为衡量标准,研究了NMM在处理线弹性断裂力学问题时的网格依赖性。研究表明,NMM即使在处理强奇异性问题时依然有着很好的网格无关性,进一步证实了它在模拟裂纹扩展问题时的鲁棒性。 相似文献
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随着工程地质力学及其相关学科的不断完善和发展及其存在问题的不断解决,工程地质力学正逐步进入一个崭新的发展阶段。本文总结了20世纪工程地质力学取得的辉煌成就和面临的巨大挑战,详细论述了工程地质力学的理论体系,包括工程地质体结构的相对性、工程地质体的连续性、工程地质体的本构关系、工程地质体的几何大变形、工程地质大变形力学设计方法等,展望了未来工程地质力学在大变形灾害工程控制材料研发、工程灾害控制、工程地质体的能量本构关系、工程地质体的能量平衡方程和地质工程的量化设计方面的走向,指出工程地质力学作为一门学科的发展仍然任重道远。 相似文献
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离散单元法同拉格朗日元法及其在岩土力学中的应用 总被引：67，自引：2，他引：67
离散单元法是一种适合于节理岩体的数值分析方法，拉格朗日元法则特点适用于解决大变形的问题。本文叙述了离散单元法和拉格朗日元法的基本原理以及有关参数的选择问题。文中还举出两种方法在岩土力学中的应用范围。 相似文献
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In modeling of many geomechanics problems such as underground openings, soil-foundation structure interaction problems, and in wave propagation problems through semi-infinite soil medium the soil is represented as a region of either infinite or semi-infinite extent. Numerical modeling of such problems using conventional finite elements involves a truncation of the far field in which the infinite boundary is terminated at a finite distance. In these problems, appropriate boundary conditions are introduced to approximate the solution of the infinite or semi-infinite boundaries as closely as possible. However, the task of positioning the finite boundary in conventional finite element discretization and the definition of the boundary and its conditions is very delicate and depends on the modeller's skill and intuition. Moreover, such a choice is influenced by the size of the domain to be discretized. Consequently, the dimensions of the global matrices and the time required for solution of the problem will increase considerably and also selection of the arbitrary location of truncated boundary may lead to erroneous result. In order to over come these problems, mapped infinite elements have been developed by earlier researchers (Simoni and Schrefier, 1987). In the present work the applicability of infinite element technique is examined for different geomechanics problems. A computer program INFEMEP is developed based on the conventional finite element and mapped infinite element technique. It is then validated using selected problems such as strip footing and circular footing. CPU time taken to obtain solutions using finite element approach and infinite element approach was estimated and presented to show the capability of coupled modeling in improving the computational efficiency. Mesh configurations of different sizes were used to explore the enhancement of both computational economy and solution accuracy achieved by incorporation of infinite elements to solve elastic and elasto-plastic problems in semi-infinite/finite domain as applied to geotechnical engineering. © Rapid Science Ltd. 1998 相似文献
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This paper is a brief account of the essential points of geomechanics initited in China by Prof. J. S. Lee in the 1920's and some important results achieved by some Chinese petroleum geologists in recent years by applying geomechanics to the exploration and prospecting of oil and gas in eastern China. 相似文献