岩石质量指标RQD与工程岩体分类

讨论了工程岩体分类中 RQD确定的某些问题 ,对正确选取 RQD指标的方法进行了探讨。     

岩石质量指标(RQD)的各向异性分析

各向异性是工程岩体的重要工程特性, 岩石质量指标RQD具明显的各向异性。本文运用结构面网络模拟技术, 通过结构面间距、倾角、相对夹角以及结构面组数的敏感性分析, 探讨了RQD的各向异性规律。结合实际工程应用, 提出正确引用RQD指标的建议。     

煤矿床工程地质勘查中岩石质量指标(RQD)存在问题的探讨

岩石质量指标(RQD)是评价岩体完整性及质量分级的一个重要指标。针对矿区工程地质勘查规范中推荐的岩体质量评价方法,详细分析了岩石质量指标(RQD)在用于岩体分类与评价中存在的岩心长度的计算、采取率、硬度和结构对其赋值大小的影响,以及对规范理解的差异,提出了解决这些问题的有效方法与途径,为岩石质量指标(RQD)的正确应用及煤矿床岩体质量合理评价做了有益的探讨。     

铁路岩质边坡的RQD研究

以宝成铁路略阳站前后一段铁路工程边坡为例,采用蒙特卡洛原理和方法,计算模拟铁路边结构面概率参数,利用统计结果估算边坡岩体的岩石质量指标ＲＱＤ,提出方向ＲＱＤ的概念,初探方向ＲＱＤ值在铁路工程边坡中的应用及铁路开挖工程活动与自然地质环境间的相互影响。     

基于空间插值的工程岩体RQD预测方法

作为工程实际中评价岩体性质的重要指标,RQD的应用已相当广泛。但工程岩体中RQD值的分布存在一定的结构性和随机性,因此,通过对特定位置钻探获取的RQD值无法很到位地表达整个空间区域的实际岩石质量。为了弥补这方面的不足,统计学中的空间插值法为此提供了有力的手段。考虑到空间RQD分布存在各向异性,以及在工程坐标系中很难描述RQD分布的结构性,首先计算工程坐标系下已获取RQD值的主要黑塞方向（pHd）;然后构建空间旋转与比例缩放矩阵对其进行坐标标准化处理。在标准化的空间中,引入Kriging插值法,采用变异函数描述RQD在标准空间结构上的变化,建立其空间变异规律的数学模型,并对其进行插值计算;最后将标准空间进行坐标逆变换,实现了对工程坐标系下RQD分布的预测。利用R语言编程将该方法应用于工程实例,结果表明,这种空间插值法能够有效地预测工程岩体中RQD值的分布规律,弥补了局部钻探的局限性。     

利用RQD对岩体完整质量评价的操作方法

岩石质量指标（RQD）是表示岩石完整性的一种指标。也是评价岩石质量的一个重要指标,利用RQD指标能达到客观准确的评价岩石质量的目的。     

补充RQD值的几类岩体质量评价图

针对ＲＱＤ值不能全面反映裂隙间跑、块体大小以及随机表象的多重尺度等问题,介绍了三种岩体质量评价图,即基于裂隙岩体分数维结构之上的分维岩体质量图、考虑裂隙长度的累积长度图、建立在不同岩块频度基础上的岩块累积频度图。根据不同图解对岩体质量进行了评价,并对岩体完整性作了划分、三种图解能较全面反映岩体质量的特点,表明它们是ＲＱＤ的有益补充。     

RQD研究的几个理论问题

岩石质量指标ＲＱＤ是岩体工程分类和稳定性评价中最常用的定量描述参数。３０多年来,ＲＱＤ的概念和理论研究有了重大进展。本文对源于工程应用的几个ＲＱＤ理论问题进行了评述,同时提出了一些新的研究思路。     

利用RQD估算岩体不同深度的平均渗透系数和平均变形模量

渗透系数是进行裂隙岩体渗流模拟的必备参数,变形模量是工程岩体数值模拟的必备参数。大量研究中忽视了渗透系数和变形模量随深度变化这一重要规律,从而影响模拟结果的可靠性。为此,探讨了利用极易获取的RQD（岩石质量指标）资料估算不同深度的渗透系数和变形模量的可行性。通过以某花岗岩体为例,研究发现,RQD均值随深度增大,渗透系数均值随深度减小,其相关性很好。因此,利用RQD估算不同深度的平均渗透系数是可行的。根据RQD随深度的变化,利用经验公式估算了不同深度的变形模量均值和变化范围。估算得到的变形模量与实测结果基本一致。     

Fault detection in 3D by sequential Gaussian simulation of Rock Quality Designation (RQD)

Gazestan phosphate ore deposit (Central Iran) is an apatite deposit which is instrumental in selecting the method of excavation. The position of fault systems and the condition of rock quality also play a role in the method used for mineral resources and ore reserves estimation. Conversely, the Rock Quality Designation (RQD) is a parameter that provides a quantitative judgment of rock mass quality obtained from drill cores. This factor can be applied to detect the fractured zones which occur due to fault systems. Additionally, the faulted areas can be determined by surface geological map and a few by core drilling. Some of the faulted areas are not distinguishable in the surface and are covered by soils, especially within 3D modeling and visualization. In this study, an attempt has been made to establish a relationship between the RQD percentages which were geostatistically simulated and faulted areas through the region. In comparison, the results showed that low RQD domains (RQD <20 %) can be interpreted as fault zones; high RQD domains (RQD >50 %) correspond to less fractured areas, and the contact between high and low RQD domain is gradual. Therefore, this categorization of RQD domains can be incorporated to detect the faulted zones in 3D models for mine design. Based on the categorization, the uncertainty within the area was calculated to introduce two new core drilling points for the completion of this phase of exploratory grid from the fault structural viewpoint, in order to have a proper model of ore reserve to estimate. It was concluded that this procedure can be utilized for conceptual comprehension of fault trends in 3D modeling for the method selection of excavation and complete the estimation procedure phase.     

Rock Quality Designation Model Formulation and Simulation for Correlated Fracture Intact Lengths

An important factor in the rock quality assessment analysis from discontinuity measurements along a scanline is the correlation of intact lengths. The autorun model and first order autorun coefficient are proposed as a method for objectively quantifying intact length correlation structure and discontinuity occurrences along any scanline. Necessary definitions for the methodology are presented on a quantitative basis such as the alternative intact length percentages and experimental autorun coefficient. An expression is proposed for the number of discontinuity occurrences along a scanline depending on the scanline length, alternate intact length percentages, and the autorun coefficient. Monte Carlo simulation technique is used with a suitable autorun model to verify this expression. A mathematical expression is derived for the expected Rock Quality Designation (RQD) value by taking into account the correlation of the intact lengths. Additional simulations show the validity of the new RQD expression. With the methodology proposed much less engineering experience and judgment are required in estimating the RQD value from scanline measurements. The application of the methodology has been presented for some field data.     

裂隙岩体渗流与应力耦合的试验研究

通过对较大尺寸的裂隙岩体试块进行不同侧压力和加载条件下的渗流试验结果研究，分析了裂隙岩体渗流与应力的耦合机理，得出了不同应力条件下裂隙岩体渗流量与应力成四次方的关系。并且得出并非压应力都引起裂隙岩体的渗流量减小，当裂隙岩体受平行于裂隙面方向的单向压应力时，渗流量随着压应力的增加而增加。     

裂隙岩体渗流模型综述

系统综述了裂隙岩体渗流分析的各类模型,从各类模型所反映的渗透机理出发,阐明了它们的优缺点和适用条件及其工程应用情况。集等效连续介质模型和离散裂隙网络模型优点的等效-离散耦合模型是有实用前景的裂隙渗流模型。     

裂隙岩体水力等效连续介质中物理量的讨论

基于力学基本原理和等效原则．总结了裂隙岩体水力等效连续介质中一些物理量的定义。其中，从力的运动效果和对应应力状态性质两方面讨论了渗透作用力，证明了水力等效连续介质中渗透作用力运动效果等效的必然性和对应应力状态性质的一致性。     

The Development of a new Numerical Modelling Approach for Naturally Fractured Rock Masses

Summary. An approach for modelling fractured rock masses has been developed which has two main objectives: to maximise the quality of representation of the geometry of existing rock jointing and to use this within a loading model which takes full account of this style of jointing. Initially the work has been applied to the modelling of mine pillars and data from the Middleton Mine in the UK has been used as a case example. However, the general approach is applicable to all aspects of rock mass behaviour including the stress conditions found in hangingwalls, tunnels, block caving, and slopes. The rock mass fracture representation was based on a combination of explicit mapping of rock faces and the synthesis of this data into a three-dimensional model, based on the use of the FracMan computer model suite. Two-dimensional cross sections from this model were imported into the finite element computer model, ELFEN, for loading simulation. The ELFEN constitutive model for fracture simulation includes the Rotating Crack, and Rankine material models, in which fracturing is controlled by tensile strength and fracture energy parameters. For tension/compression stress states, the model is complemented with a capped Mohr-Coulomb criterion in which the softening response is coupled to the tensile model. Fracturing due to dilation is accommodated by introducing an explicit coupling between the inelastic strain accrued by the Mohr-Coulomb yield surface and the anisotropic degradation of the mutually orthogonal tensile yield surfaces of the rotating crack model. Pillars have been simulated with widths of 2.8, 7 and 14 m and a height of 7 m (the Middleton Mine pillars are typically 14 m wide and 7 m high). The evolution of the pillar failure under progressive loading through fracture extension and creation of new fractures is presented, and pillar capacities and stiffnesses are compared with empirical models. The agreement between the models is promising and the new model provides useful insights into the influence of pre-existing fractures. Further work is needed to consider the effects of three-dimensional loading and other boundary condition problems.     

地下洞室围岩稳定性分析方法简述

随着可持续发展战略的提出,地下工程的开发和利用显得尤为重要。地下洞室围岩稳定性是整个工程中的关键问题,现今对地下洞室围岩稳定性研究的分析方法有很多,为了明确各种研究方法的优缺点以及适用范围,本文对现有地下洞室围岩稳定性分析方法进行了分类总结,用系统性的方法从定性、定量、可靠度等方面考虑,主要包括洞室的整体稳定性分析和洞室局部块体的稳定性分析,研究结果对地下洞室围岩稳定性设计及计算有重要的意义,最后对相关研究的现状和发展趋势做了简述。     

裂隙岩体中的对流扩散研究

揭示一个基于代数拓扑理论的裂隙网络中物质弥散模型，还给出了应用于网络中的对流扩散的对应性原理的证明。应用拓扑理论给出的框架，使其起了一个数据结构的组织者的作用，由此得到网络中每一个分支上的浓度的解。这个解是在拉普拉斯空间上的解析解。网络中任意点在任何时刻的浓度可以很方便地用数值拉氏反变换求出。     

岩体等效变形参数研究

岩体变形参数的确定对岩体稳定性模拟至关重要.提出了确定规则裂隙和不规则裂隙岩体等效变形参数的一种模型, 探讨了岩体等效变形参数的规律.通过对不考虑渗流-应力耦合时岩体等效变形性能的研究, 可以发现岩体的等效变形参数不仅与各组结构面的几何形态、结构面变形参数、岩块变形参数等有关, 而且与不同组系结构面间的交切形态有关.岩体的REVs具备以下几点规律: 首先REVs具有多尺度效应和不确定性.其次, REVs与结构面各几何形态要素之间有如下关系: 平均迹长越大, 平均间距越小, 方向角的方差越大, 结构面分布越凌乱, REVs的取值越小.REVs与岩块、结构面变形参数之间有如下关系: 结构面变形参数与岩块变形参数的差异程度对REVs的取值没有明显影响, 但是不同组系结构面或是同一组中的各条结构面, 其变形参数差异越小, REVs的取值将越小.