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1.
Application of Fuzzy Set Theory to Rock Engineering Classification Systems: An Illustration of the Rock Mass Excavability Index 总被引：1，自引：0，他引：1
Jafar Khademi Hamidi Kourosh Shahriar Bahram Rezai Hadi Bejari 《Rock Mechanics and Rock Engineering》2010,43(3):335-350
The characterization of rock masses is one of the integral aspects of rock engineering. Over the years, many classification
systems have been developed for characterization and design purposes in mining and civil engineering practices. However, the
strength and weak points of such rating-based classifications have always been questionable. Such classification systems assign
quantifiable values to predefined classified geotechnical parameters of rock mass. This results in subjective uncertainties,
leading to the misuse of such classifications in practical applications. Fuzzy set theory is an effective tool to overcome
such uncertainties by using membership functions and an inference system. This study illustrates the potential application
of fuzzy set theory in assisting engineers in the rock engineering decision processes for which subjectivity plays an important
role. So, the basic principles of fuzzy set theory are described and then it was applied to rock mass excavability (RME) classification
to verify the applicability of fuzzy rock engineering classifications. It was concluded that fuzzy set theory has an acceptable
reliability to be employed for all rock engineering classification systems. 相似文献
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Omid Saeidi Seyed Rahman Torabi Mohammad Ataei 《Rock Mechanics and Rock Engineering》2014,47(2):717-732
Rock mass classification systems are one of the most common ways of determining rock mass excavatability and related equipment assessment. However, the strength and weak points of such rating-based classifications have always been questionable. Such classification systems assign quantifiable values to predefined classified geotechnical parameters of rock mass. This causes particular ambiguities, leading to the misuse of such classifications in practical applications. Recently, intelligence system approaches such as artificial neural networks (ANNs) and neuro-fuzzy methods, along with multiple regression models, have been used successfully to overcome such uncertainties. The purpose of the present study is the construction of several models by using an adaptive neuro-fuzzy inference system (ANFIS) method with two data clustering approaches, including fuzzy c-means (FCM) clustering and subtractive clustering, an ANN and non-linear multiple regression to estimate the basic rock mass diggability index. A set of data from several case studies was used to obtain the real rock mass diggability index and compared to the predicted values by the constructed models. In conclusion, it was observed that ANFIS based on the FCM model shows higher accuracy and correlation with actual data compared to that of the ANN and multiple regression. As a result, one can use the assimilation of ANNs with fuzzy clustering-based models to construct such rigorous predictor tools. 相似文献
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基于模糊集重心理论的岩体分类 总被引：2，自引：0，他引：2
将模糊综合评判方法应用于岩体分类可造成评判信息丢失,影响评判结果的准确性和可信度。针对该缺陷,引入模糊集重心理论,克服了综合评判方法中某些因素由于权值较小而被“淹没”的现象。在此基础上,选取了岩石质量指标、单轴抗压强度、岩体完整性系数、岩石软化系数、最大地震烈度和地下水渗水量这6个对岩体质量及其稳定性影响比较大的因素,以正态分布作为其隶属函数,采用加权平均值法确定各因素权重值,建立了基于模糊集重心理论的岩体模糊分类方法。结合具体的工程实例,阐明了上述各因素模糊集重心的计算方法。利用基于模糊集重心的岩体模糊分类方法,研究了某一地下工程围岩的稳定性级别,并与模糊综合评判方法计算的结果和围岩的实际稳定情况进行了对比,验证了方法的准确性和适用性。 相似文献
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基于三维地层模型的岩体质量可视化分级 总被引：6，自引：3，他引：3
岩体质量分级是岩石力学学科研究的热点和难点,在水电工程建设中具有重要的实际意义。在对岩级分类方法进行大量研究之后,工程人员对岩级结果的表达有了更高的要求,传统的方式已不能满足人们空间分析的需要,研究岩体质量可视化分级十分必要。首先,利用NURBS工具以一种新的数据结构和方法重建三维地层模型,然后,基于岩体质量分级结果,按照空间图形集合运算算法生成相应的三维岩级模型。将上述理论方法应用到锦屏一级水电工程岩体质量分级评价中,并进行了一系列与工程相关的岩级可视化分析,获得了很好的应用效果。 相似文献
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Visualization of rock mass classification systems 总被引：2，自引：1，他引：2
A rock mass classification system is intended to classify and characterize the rock masses, provide a basis for estimating
deformation and strength properties, supply quantitative data for mine support estimation, and present a platform for communication
between exploration, design and construction groups. In most widely used rock mass classification systems, such as RMR and Q systems, up to six parameters are employed to classify the rock mass. Visualization of rock mass classification systems in
multi-dimensional spaces is explored to assist engineers in identifying major controlling parameters in these rock mass classification
systems. Different visualization methods are used to visualize the most widely used rock mass classification systems. The
study reveals that all major rock mass classification systems tackle essentially two dominant factors in their scheme, i.e.,
block size and joint surface condition. Other sub-parameters, such as joint set number, joint space, joint surface roughness,
alteration, etc., control these two dominant factors. A series two-dimensional, three-dimensional, and multi-dimensional visualizations
are created for RMR, Q, Rock Mass index RMi and Geological Strength Index (GSI) systems using different techniques. In this manner, valuable insight into these rock mass classification systems is gained. 相似文献
7.
岩体质量Q系统分类法及其应用 总被引：3，自引：0，他引：3
岩体质量分类Q系统(以下简称Q系统)是目前应用最广的岩体质量分类方法之一。该方法是1974年挪威的巴顿(Barton)等人建立起来的,并且在长期工程实践中进行过多次修正。论文详细介绍了巴顿于2002年最新修正后的Q系统,并成功应用于西南某水电站坝址区岩体质量分级研究中。最后与其他分级方法进行了对比分析,显示了很好的相关性。 相似文献
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一种基于块体化程度理论的裂隙岩体巷道顶板稳定性分级方法研究 总被引：1，自引：0，他引：1
岩体完整性是进行巷道顶板稳定性分级的一个重要指标,当前分级方法均是从一维角度对岩体结构进行描述,不能全面刻画出三维空间上顶板围岩的完整性。针对这一缺陷,引入裂隙岩体块体化程度理论,以块体化程度代替常规标准中表征岩体完整性的岩体质量RQD值和节理间距两项子指标,开展裂隙岩体巷道顶板稳定性分级研究,创新形成了一种适用于裂隙岩体顶板稳定性分级的BT分级方法。以块体百分比和块体体积曲线为基本依据,构建出裂隙岩体巷道顶板围岩块体化程度的解算流程;运用AHP法对稳定性影响因素权重进行了排序,制定出稳定性分级方法与标准。以铜坑矿92号矿体裂隙岩体试验区巷道顶板结构面调查数据和岩石力学参数为基础,运用传统分级方法RMR法和BT法分别对各试验区巷道顶板稳定性进行评价,对两种分级结果进行比较分析,结果表明：与传统的RMR法相比,BT法在稳定性描述、分级准确性和安全管理指导作用等方面更为优越,更能够客观真实地反映出裂隙岩体巷道顶板稳定性。研究成果可为复杂裂隙岩体条件下的巷道顶板安全分级与管理提供更为可靠的科学依据。 相似文献
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The joint frequency rating index accounts for 40% of the weight in the hundred-mark Rock Mass Rating 2014 (RMR14) classification system. However, owning to the natural variations of in-situ rock mass, this parameter is difficult for site engineers to obtain along the tunnel axis, especially in groundwater-rich conditions or prior to any disturbances made to rock mass. In this study, we propose an equivalent joint frequency, expressed quantitatively in terms of the ratio of the P-wave propagation velocity in the rock mass to that of the intact rocks, which is mainly based on engineering statistics easily obtained from the Chinese National Standard, GB/T 50218. We also explore a new rating method, based on field P-wave propagation velocity tests, for the joint frequency in the RMR14 classification system. Literature from in-situ databases is discussed to verify the applicability of the proposed rating method. The verifications demonstrate that, compared with the results of on-site parameters ratings as per the RMR classification system, the new rating method using P-wave propagation velocity can obtain a certain degree of accuracy. Hence, this enables the presentation of the primary state of integrity of an in-situ rock mass in accordance with the RMR14 classification system, through simple and non-destructive field P-wave velocity tests.
相似文献13.
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Analysis of support requirements for a shallow diversion tunnel at Guledar dam site, Turkey 总被引：2，自引：0，他引：2
Engineering geological properties and support design of a planned diversion tunnel at Guledar dam site, which was located at the North of Ankara, Turkey were studied in this article. The main purpose of the construction of the planned tunnel is to regulate, drainage and to provide water for irrigation purposes. The diversion tunnel runs mainly through formations of limestone, sandstone and diabase. Rock masses at the site were characterized using Rock Mass Rating (RMR), Rock Mass Quality (Q), Rock Mass Index (RMi) and Geological Strength Index (GSI). RMR, Q, RMi and GSI were determined by using field data and mechanical properties of intact rock samples, measured in the laboratory. Support requirements for the planned diversion tunnel were determined accordingly in terms of the rock mass classification systems. Recommended support systems by empirical methods were also analyzed using 2D Finite Element method. Calculated parameters based on empirical methods were used as input parameters in the finite element models. The results from both methods were compared with each other. This comparison suggests that more reliable support design could be achieved by using the finite element method together with the empirical methods. 相似文献
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概述了有关规范建议的两个评判方法及其指标;建立了相应的隶属函数;运用模糊综合评判理论求解了围岩岩体质量类别的模糊向量。 相似文献
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国标BQ分级方法是一种多因素、多变量、定性与定量结合的分级方法,该方法选取岩石饱和单轴抗压强度和岩体完整性指数计算出岩体基本指标,再考虑到工程岩体现场工况对其修正,既保证了分级的客观性,又降低了现场分级的难度。但在一些复杂地质条件下,如层状岩体等,BQ分级存在修正系数定性评价的局限性。由于现场工程人员的主观判断不同,导致两种岩体分级交界处往往会出现分级交错的现象。基于室内力学试验,本文阐述了层理倾角与围压对层状岩体力学参数的影响规律。采用Jaeger-Donath与Mogi-Coulomb强度准则提出针对层状岩体的结构面产状修正系数K2以及初始地应力状态修正系数K3的计算公式,并通过木寨岭铁路隧道围岩分级计算进行了验证。 相似文献
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ABSTRACT The local site experience is a valuable component for the success of rock mass classification systems as tunnel design methods. The Ituango hydroelectric project is a very important source of information in order to evaluate the usefulness of the main rock mass classification systems. The objective of this research is to improve understanding of some important features of excavated rock mass, such as discontinuities, block size, shear strength and joint alteration, by analyzing some hundreds of data obtained during excavation cycle. The field study included a survey of exposures after drilling and blasting rounds. Rock mass classification and support measures for each type of terrain along 1400 m tunnel were performed. The rock mass classes could be better explained if shear strength, alteration or block size is calculated. The assessment of these data allows evaluating the block fall risk, improving support and liner. A local correlation between the RMR and Q system was also obtained. 相似文献
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岩体质量等级分类在实际的工程中有着很重要的作用。基于主成分分析（PCA）法和与Fisher判别分析法相结合建立岩体质量等级判别模型,选取单轴抗压强度、岩体体积节理数、声波纵波速度、节理面风化变异系数、节理面粗糙度系数和透水性系数6种指标作为岩体质量分级判别的判别因子。以永平铜矿露天矿区工程岩体特征资料中的20个样本为训练样本,10个为待判样本,对该模型进行检验和应用,并与传统的RMR法、Fisher判别分析模型的结果进行比较,相应正确率分别为87%、70%、77%,判断结果表明利用主成分分析法和Fisher判别分析法建立的模型判别能力更高。 相似文献
20.
方玉树 《中国地质灾害与防治学报》2011,22(4):89-95
当前的建筑边坡岩体分类不含外倾软弱结构面控制的边坡和倾倒崩塌型破坏的边坡,把岩体完整程度、结构面结合程度、结构面产状、岩石坚硬程度和地下水发育程度作为分类因素。对这种分类及其应用存在的问题进行了分析。研究表明,这个分类在分类规律、分类对象、分类因素等方面均不合理,也没有实际意义,已有的关于岩体性状的通用分类和专用于边坡的单因素分类对于边坡工程已经够用。提出了取消专用于边坡的岩体综合分类的建议。 相似文献