层状岩石倾角对弹性模量的影响研究

层理倾角对互层复合岩体的力学特性和物理参数等具有显著的影响,为研究层状岩石倾角对互层复合岩体弹性模量的影响,首先推导出水平状互层复合岩体平行于层理方向和垂直于层理方向的弹性模量,进而推导了层理倾角与互层复合岩体弹性模量关系的解析解,并通过不同层理倾角页岩的单轴抗压实验验证了解析解的正确性。     

横观各向同性岩体中位移反分析的测点优化布置

在地下工程中,位移监测已经成为掌握围岩动态变化的关键手段。而测量点的布置对位移反分析的唯一性和反分析精度都有很大的影响。基于最大位移原则,对横观各向同性岩体位移反分析中的测点优化布置问题进行了研究。研究了圆形巷道中位移随角度和半径的变化规律;分析了侧压力系数λ对位移变化规律的影响;获得了测点优化布置准则。研究结果表明,在较大主应力方向靠近硐壁的区域是最优的测点布置区域。     

用解析法反演非均匀应力场巷道围岩的物性参数

本文用解析法对非均匀受压巷道进行位移反分析，推导了岩石物性参数的表达式。并讨论了在已知垂直位移和水平位移的情况下，水平侧压力系数、弹性模量等与位移比的关系．     

用解析法反淀非均匀应力场巷道围岩的物性参数

本文用解析法对非均匀受压巷道进行移反分析，推导了岩石物性参数的表达式，并讨论了在已知垂直位移和水平位移的情况下，水平侧压力系数，弹性模量等与位移比的。     

金山金矿矿岩力学特征试验研究

通过对金山金矿矿岩的抗拉强度、抗压强度、抗剪强度、泊松比、弹性模量、内摩擦角以及内聚力的室内试验,分析了金山金矿矿岩力学特征,提出了矿体、上下盘围岩各向同性特征差,呈现出较强的各向异性特征。在实际工程应用中,应按各向异性矿岩来处理。     

数值方法中岩体力学参数的选择

对岩体工程数值计算方法中节理岩体力学模型（包括变形特性、强度特性）的选取进行了分析总结。结果表明，节理岩体的强度模型与变形掀起性都与岩体中的岩块材料性质、岩体中结构面性质及其分布形成以及所处的地应力环境有关，提供了不同条件下的岩体力学模型的数学表达式，为数值计算中节理岩体力学模型的选取提供参考。     

诱导巷道的围岩松动破坏区数值研究

当前多数矿山已进入深部开采,而深部硬岩具有高储能、受扰动易破坏的特征,根据这些特点,在矿体中布置巷道诱导岩体破裂,为后续机械开采提供可能。以贵州开阳磷矿为工程背景,利用FLAC^3D软件模拟深部巷道开挖,研究断面形状、地应力水平和侧压系数对巷道开挖的影响,从而得出岩体的破裂规律。数值模拟结果表明：巷道断面形状对围岩变形影响较大,而矩形巷道周围岩体产生的位移和塑性破坏区均最大;巷道位移和塑性破坏区随应力水平的增加而增大;围岩破坏和位移随侧压系数的增大表现出先减小后增大的趋势。在高应力水平和高侧压系数下,采用矩形断面方式开挖巷道,围岩产生的位移和塑性破坏区最大,致裂效果最好,有利于机械切割回采。     

岩体构造特征评价指标分布规律研究及其在岩体质量评价中的应用

岩体中广泛存在规模不等、性质各异的结构面,是控制岩体稳定性的重要因素。深入了解工程岩体的构造特征,也是组织矿山设计和施工的前提。本文以影响岩体工程稳定性的岩体结构面为主要研究对象,以实际矿山为例,在大量钻孔资料的基础上,通过分析岩体的工程地质条件及各种力学特性,得出岩体构造特征指标的统计分布规律,然后结合岩体质量分类方法,对矿岩体进行质量评价分级。研究结果很好的揭示了工程岩体的整体性质,对矿山的后续工作具有重要的指导意义。     

岩体构造特征评价指标分布规律研究及其在岩体质量评价中的应用

岩体中广泛存在规模不等、性质各异的结构面,是控制岩体稳定性的重要因素。深入了解工程岩体的构造特征。也是组织矿山设计和施工的前提。本文以影响岩体工程稳定性的岩体结构面为主要研究对象．以实际矿山为例．在大量钻孔资料的基础上,通过分析岩体的工程地质条件及各种力学特性,得出岩体构造特征指标的统计分布规律。然后结合岩体质量分类方法,对矿岩体进行质量评价分级。研究结果很好的揭示了工程岩体的整体性质．对矿山的后续工作具有重要的指导意义。     

节理岩体损伤的分形研究

在岩石材料损伤模型的基础上,把损伤力学与分形理论结合起来推导节理岩体损伤的本构方程,定性分析反映岩体损伤程度的分维数ｍ和Ｄ关系,最后给出ｍ、Ｄ的确定方法。     

Estimating Subgrade Reaction Modulus for Transversely Isotropic Rock Medium

Most of the rock medium possesses intrinsic grain orientation or preferred bedding and joint directions, thus requiring the use of at least transverse isotropy to describe its elastic behavior. This paper presents a series of charts, based on extensive finite element parametric studies along with nonlinear regression analysis of FE simulation results, for estimating the subgrade reaction modulus (or initial tangent to the p-y curve) using five elastic constants of a transversely isotropic rock mass. The proper characterization of subgrade reaction modulus is critical for accurate prediction of the elastic lateral deflection of a rock socketed drilled shaft under the applied lateral loads. The sensitivity of the response of a laterally loaded drilled shaft to the degree of anisotropy and orientation of the plane of anisotropy (bedding plane direction of the rock medium) was demonstrated in this paper for an actual lateral load testing case in Ohio. It is highly recommended to use five elastic constants to estimate subgrade reaction modulus of rock medium exhibiting high degree of cross anisotropy.     

Elastic Solutions for a Transversely Isotropic Half‐Space Subjected to Arbitrarily Shaped Loads Using Triangulating Technique

Elastic closed‐form solutions for the displacement and stresses in a transversely isotropic half‐space subjected to a buried right triangular loaded region are presented. The loading types include a uniform load, a linearly varied load in the X‐direction, and a linearly varied load in the Y‐direction, respectively. The planes of transverse isotropy are assumed to be parallel to its horizontal surface. These solutions are obtained from integrating the point load solutions in a transversely isotropic half‐space. The exact solutions indicate that the displacements and stresses are influenced by several factors, such as the buried depth, the loading types, the dimensions of loaded region, and the degree and type of material anisotropy. Two illustrative examples are presented to investigate the effect of various parameters on the displacement and stress induced by uniform/linearly varying triangular loads. The results indicate that the displacement and stress distributions accounted for rock anisotropy are quite different for those calculated from isotropic solutions. Besides, an example to demonstrate the extension of triangular loading solutions to calculate the stress due to arbitrarily shaped loads is also illustrated. It is shown that the usage of triangulating technique for calculating the displacements and stresses due to any type of loaded area is simple, efficient, as well as accurate enough. This method can be a practical alternative to the existing numerical and graphical methods.     

一种块体–颗粒–杆件的耦合方法及其在隧道支护模拟中的应用

为了模拟隧道开挖过程中边帮的失稳垮塌过程以及锚杆对隧道的支护过程,提出了一种基于罚弹簧的块体–颗粒–杆件的耦合方法.该耦合方法基于连续–非连续的数值模拟方法(CDEM),采用离散颗粒簇表征隧道周边松动圈以内的破碎岩体,采用块体单元表征松动圈以外的完整岩体,采用杆件单元描述锚杆及锚索等杆系类支护结构,采用插值耦合的方式实现杆件单元与离散颗粒及块体单元间力与位移的传递,从而实现高应力环境下隧道开挖失稳过程的模拟及支护效果的评价.颗粒与块体之间采用1根法向线性弹簧及2根切向线性弹簧进行耦合,法向弹簧引入拉伸断裂本构,切向弹簧引入Mohr–Coulomb脆性断裂本构.杆件与颗粒及杆件与块体之间的耦合模式基本一致,包含1根沿着杆件轴向的罚弹簧S_gn及1根垂直于杆件轴向的罚弹簧S_gs,S_gn主要用于描述杆件与围岩之间的拉拔效应及推压效应,S_gs则主要用于描述杆件与围岩之间的侧向挤压效应.圆形盾构隧道弹性场分析、预应力锚杆加固矩形巷道模拟、全长连接锚杆对岩块的锚固作用分析、以及碎裂岩体中的隧道开挖支护效果分析等案...     

基于三维激光扫描点云数据的地下巷道岩体结构面识别及稳定性分析

巷道围岩中发育的结构面对巷道稳定性有很大的影响,开展地下巷道的工程地质调查,精确获取地下巷道围岩结构面信息是巷道稳定性分析的关键。以云南大红山铁矿775 m 中段运输巷道为研究对象,采用三维激光扫描仪获取围岩结构面点云数据,并利用点云数据处理软件进行误差处理、坐标校正、结构面数据提取、点云拼接和过滤抽稀等内业数据处理工作,基于处理结果开展了统计分析;利用离散元软件3DEC建立了离散结构网络模型与地下巷道合成岩体模型,并对该巷道在自重及爆破振动作用下的失稳概率进行了数值模拟。结果表明：三维激光扫描技术可较好地获取巷道围岩的结构面信息,结合离散块体单元计算软件对巷道岩石块体的稳定性进行进一步分析,所分析区域的围岩自稳能力较好,但在爆破振动影响下失稳概率大幅增加,研究结果可为巷道的支护设计提供理论指导。     

基于应变软化深埋巷道含水围岩的弹塑性极限平衡分析

在岩体内开挖巷道后,由于干扰了原岩应力分布和渗透水压力的作用,巷道含水围岩中呈现次生应力,这种新出现的不平衡应力是引起岩体产生变形、位移,甚至破坏的主要根源.以圆形截面巷道为例,结合莫尔-库仑理论从围岩弹塑性变形的角度出发,在考虑了围岩应变软化所引起围岩损伤的基础上,计算和分析了地下巷道含水围岩达到极限平衡时围岩塑性区...     

Analytical Elastic Solution Based on Fourier Series for a Laterally Confined Granular Column

This paper presents an analytical solution methodology for the complete stress and displacement fields of a laterally confined granular column loaded from the top end. The granular column is idealized as a homogeneous isotropic elastic medium with Coulomb’s friction at the lateral boundary. The solution methodology consists of an analytical procedure that incorporates a potential approach with trigonometric series and Bessel functions, finite Fourier transforms and the superposition method, and an iterative algorithm to satisfy the Coulomb’s friction condition at the lateral boundary. Stress and displacement fields are computed for a specific example and found completely consistent with corresponding finite element results. Key characteristics, computational errors, the convergence behavior, and restrictions of the present approach are discussed. The methodology developed herein can be beneficially applied in the validation process of numerical simulation techniques in granular mechanics such as finite or discrete element methods.     

Principal Deviatoric Strain Increment Ratios for Sand Having Inherent Transverse Isotropy

The behavior of sand on the π plane, including the relation between the principal deviatoric strain increment ratios, is not fully understood. The objectives are: To clarify experimentally the relation between the principal deviatoric strain increment ratios for sand in a wide range of b values and to discuss the basic shear behavior, taking particular notice of inherent transverse isotropy and noncoaxiality. From the experimental results on sand with inherent transverse isotropy, it was observed that the relation between the principal deviatoric strain increment ratios is fundamental and is related to the shape of the failure surface and the extent of strain localization. A new equation for the principal deviatoric strain increment ratios is proposed to model the influence of the incremental stress.     

冲击荷载下岩石裂纹扩展研究进展

为了给深部资源开采和大型地下空间工程中围岩体的变形机理及稳定性控制提供理论基础,通过查阅大量关于表征岩石裂纹扩展的裂纹扩展模型、应力强度因子和断裂韧性的国内外文献,总结了前人的研究成果。依据现有研究,提出了动荷载作用下岩石裂纹扩展的几点建议：（1）综合考虑弹性力学、断裂力学和损伤力学建立岩石材料从微观断裂到宏观破坏这一演变过程的理论模型,使理论模型更加适应岩石材料的非线性特征;（2）采用分形、自组织和混沌等非线性理论表征动荷载作用下岩石内部以及表面裂纹的扩展演化特征;（3）采用颗粒离散元和有限差分模拟岩石材料裂纹扩展演化特征。     

考虑围岩松动圈支护体影响的深埋圆形隧道衬砌优化设计

首先考虑围岩松动圈支护体的影响,在完全接触条件下,根据弹塑性力学理论,推导出深埋圆形隧道每层衬砌切向应力和径向应力分量的解析解;然后根据混凝土和围岩材料受力状态的不同,选用不同的破坏准则,引入功能梯度材料思想,构建了不同弹性模量双层混凝土圆形衬砌优化设计的目标函数,即当目标函数为最小值时,Ⅰ、Ⅱ和Ⅲ层结构同时接近或达到预设破坏状态,在设计上才最为合理;最后对衬砌材料的弹性模量和衬砌厚度分别进行了优化设计.算例分析表明:(1)随着围岩应力的增大,E₂/E₁和E₂/E₃都减小.在相同大小的围岩应力作用下,总有E₂/E₁2/E₃,故而建议设计时Ⅰ层衬砌的弹性模量应大于围岩松动圈支护体的弹性模量.(2)随着围岩应力的增大,Ⅰ层衬砌的厚度增大.在相同大小的围岩应力作用下,当E₂/E₁>E₂/E₃时所求得的Ⅰ层衬砌最优厚度总是小于E₂/E₁2/E₃时所求得的Ⅰ层衬砌厚度,故而可通过改变Ⅰ层衬砌和围岩松动圈支护体的弹性模量相对大小来调整Ⅰ、Ⅱ层衬砌的厚度.      

Direct Numerical Procedure for Solution of Moving Oscillator Problems

In this paper, the problem of a 1D elastic distributed system coupled with a moving linear oscillator, often referred to as the “moving oscillator” problem, is studied. The problem is formulated using a “relative displacement” model, which shows that, in the limiting case of infinite oscillator stiffness, the moving mass problem is recovered. The coupled equations of motion are recast into an integral equation that is amenable to solution by a direct numerical procedure. Both the integral equation and the numerical procedure show that the response of the elastic system at the current time depends only on the time history of its response at the positions of the oscillator. Numerical results are presented for the examples of a string and a simply supported beam and are compared to the moving force solutions. It is shown that the oscillator, with its stiffness suitably tuned, can excite the elastic structure into resonance.