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充分认识岩石的地质本质性是准确描述其物理力学特性的桥梁。岩石的地质本质性涵盖了岩石的物质性、结构性和赋存状态3个方面的内容。在综合考虑岩石上述3方面特征及其与单轴试验联系的基础上,以矿物组成、密度、纵波波速和含水状态为基本指标,采用回归和BP神经网络的方法对碳酸盐岩单轴抗压强度进行预测,并采用灰色关联分析法验证本研究所选用的预测基本指标的合理性。实例应用表明:本次采用的回归方法对该类岩石强度预测的最大误差为15.3%,BP神经网络方法预测的最大误差为8.5%。预测误差出现的原因为碳酸盐岩物质组成复杂,所选预测基本指标是实际情况的简化,同时泥灰质岩石所具有的膨胀性也导致实测和预测结果具有一定的差异。 相似文献
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Tang Zhu Li Shuqing Huang Shouqing Huang Fei Wan Fangfang 《Geotechnical and Geological Engineering》2021,39(5):3843-3862
Geotechnical and Geological Engineering - Uniaxial compressive strength is an important mechanical parameter for rock mass engineering. Hence, how to determine the UCS simply and accurately have... 相似文献
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Abrasivity Assessment of Granitic Building Stones in Relation to Diamond Tool Wear Rate Using Mineralogy-Based Rock Hardness Indexes 总被引:1,自引:1,他引:0
Nurdan Güneş Yılmaz 《Rock Mechanics and Rock Engineering》2011,44(6):725-733
The objective of the present study was to determine the abrasive wear potential of granites in circular sawing using some
mineralogy-based rock hardness indexes. A literature study indicated that little or no attention has been given to assessing
this kind of relationship in the field of stone processing. To accomplish this objective, sawing experiments were performed
on nine different granites used widely as building and decorative stone materials. The measured sawblade-specific wear rates
were correlated with three different rock hardness indexes attained by combining the percentage content of hard mineral constituents
with their known hardness values. Statistical analysis of the experimental data revealed that rock hardness indexes that are
based on both Vickers hardness number and Rosiwal hardness could be accepted as reliable indicators of granite abrasivity.
These two indexes were also found to correlate well with the average power drawn during the process. However, the rock abrasivity
index based on Mohs relative scratch hardness did not show statistically significant correlations with sawblade wear rate
and power drawn. Although quartz percentage content is regarded as an important abrasivity parameter by practitioners, the
observations made here indicate that consideration of quartz percentage content alone is not sufficient to describe the abrasive
potential of granites, and thus incorporation of other hard mineral constituents could be more suitable. 相似文献
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B. Rajesh Kumar Harsha Vardhan M. Govindaraj 《Rock Mechanics and Rock Engineering》2011,44(5):613-620
The main purpose of the study is to develop a general prediction model and to investigate the relationships between sound
level produced during drilling and physical properties such as uniaxial compressive strength, tensile strength and percentage
porosity of sedimentary rocks. The results were evaluated using the multiple regression analysis taking into account the interaction
effects of various predictor variables. Predictor variables selected for the multiple regression model are drill bit diameter,
drill bit speed, penetration rate and equivalent sound level produced during rotary drilling (L
eq). The constructed models were checked using various prediction performance indices. Consequently, it is possible to say that
the constructed models can be used for practical purposes. 相似文献
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Estimating Abrasivity of Rock by Laboratory and In Situ Tests 总被引:1,自引:0,他引:1
The degree to which a rock abrades another rock is called its “abrasivity”. Laboratory tests of abrasivity can be broadly
divided into four kinds: drilling, rubbing, turning-operation and tumbling tests. The present study was initiated 30 years
ago with the objective of investigating and developing methods for measuring rock abrasivity, and making some contribution
towards understanding the relationships between the above test methods. Within the range of tests conducted, the turning-operation
test turned out to be superior to the drilling test, albeit slightly, in terms of practicality. We have also conducted in
situ tests using rock drills for the last 20 years. The results of those tests have been investigated and compared with the
results of laboratory tests. There is a large degree of scatter in the data on gauge loss in button bits, which has obscured
any correlations with laboratory data. Some correlations were found between height loss in button bits and laboratory findings. 相似文献
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A Simplified Failure Criterion for Intact Rocks Based on Rock Type and Uniaxial Compressive Strength 总被引:2,自引:1,他引:1
Jiayi Shen Rafael Jimenez Murat Karakus Chaoshui Xu 《Rock Mechanics and Rock Engineering》2014,47(2):357-369
The uniaxial compressive strength (UCS) of intact rock, which can be estimated using relatively straightforward and cost-effective techniques, is one of the most practical rock properties used in rock engineering. Thus, constitutive laws to represent the strength and behavior of (intact) rock frequently use it, along with additional intrinsic rock properties. Although triaxial tests can be employed to obtain best-fit failure criterion parameters that provide best strength predictions, they are more expensive and require time-consuming procedures; as a consequence, they are often not readily available at early stages of a project. Based on the analysis of an extensive triaxial test database for intact rocks, we propose a simplified empirical failure criterion in which rock strength at failure is expressed in terms of confining stress and UCS, with a new parameter which can be directly estimated from the UCS for a specified rock type in the absence of triaxial test data. Performance of the proposed failure criterion is then tested for validation against experimental data for eight rock types. The results show that strengths of intact rock estimated by the proposed failure criterion are in good agreement with experimental test data, with small discrepancies between estimated and measurements strengths. Therefore, the proposed criterion can be useful for preliminary (triaxial) strength estimation of intact rocks when triaxial tests data are not available. 相似文献
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Nagappan Kabilan M. Muttharam V. Elamathi 《Geotechnical and Geological Engineering》2017,35(6):2625-2636
This research paper is aimed to briefly highlight the correlation between unconfined compressive strength and point load index for jointed rocks based on joint asperity & orientation. In this observe, specimens were tested to obtain their unconfined compression strength and point load index for a different joint condition. The different joint conditions considered for this study were clean joint and joint filled condition. For both clean joint and joint filled specimens were prepared by various asperity angles of 30°, 45°, 60° and 90° with different orientation angles such as 0°, 30°, 45°, 60°, 90°. Plaster of Paris was used as model material to simulate weak rock mass in the field. By testing intact model specimens for unconfined compressive strength leads to revealing of optimum moisture content for further testing. The curing period for the model specimens is 3 days at room temperature. To simulate jointed rocks, various moulds of different orientation of joint with respect to major principal stress are prepared separately. The inner diameter of the mould is 50 mm and height is 100 mm. After casting, a rough joint was created by cutting the prepared sample using the cutter. The specimens are tested for both clean joint and joint filled condition to determine the favorable joint orientation and asperity angle. After curing, the specimens are tested for unconfined compressive strength and Point load index. The new multi-linear correlation for determining unconfined compressive strength with the help of point load index is developed and cross checked with equations formed for actual rock. On comparing both results it is found that the new equation can suitable for assessing the unconfined compressive strength of limestone and serpentinite rocks through point load index value. 相似文献
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Aladejare Adeyemi Emman Alofe Emmanuel Damola Onifade Moshood Lawal Abiodun Ismail Ozoji Toochukwu Malachi Zhang Zong-Xian 《Geotechnical and Geological Engineering》2021,39(6):4427-4455
Geotechnical and Geological Engineering - Empirical relationships for estimating Uniaxial Compressive Strength (UCS) of rock from other rock properties are numerous in literature. This is because... 相似文献
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V. Palchik 《Rock Mechanics and Rock Engineering》2011,44(1):121-128
The ratios M
R = E/σ
c for 11 heterogeneous carbonate (dolomites, limestones and chalks) rock formations collected from different regions of Israel
were examined. Sixty-eight uniaxial compressive tests were conducted on weak-to-strong (5 MPa < σ
c < 100 MPa) and very strong (σ
c > 100 MPa) rock samples exhibiting wide ranges of elastic modulus (E = 6100–82300 MPa), uniaxial compressive strength (σ
c = 14–273.9 MPa), Poisson's ratio (ν = 0.13–0.49), and dry bulk density (ρ = 1.7–2.7 g/cm3). The observed range of M
R = 60.9–1011.4 and mean value of M
R = 380.5 are compared with the results obtained by Deere (Rock mechanics in engineering practice, Wiley, London, pp 1–20,
1968) for limestones and dolomites, and the statistical analysis of M
R distribution is performed. Mutual relations between E, σ
c, ρ, M
R for all studied rocks, and separately for concrete rock formations are revealed. Linear multiple correlations between E on the one hand and σ
c and ρ on the other for Nekorot and Bina limestone and Aminadav dolomite are obtained. It is established that the elastic modulus
and M
R in very strong carbonate samples are more correlated with ρ−σ
c combination and ε
a max, respectively, than in weak to strong samples. The relation between M
R and maximum axial strain (ε
a max) for all studied rock samples (weak-to-strong and very strong) is discussed. 相似文献
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Estimation of Rock Cuttability from Shore Hardness and Compressive Strength Properties 总被引:6,自引:1,他引:6
Summary Shore hardness has been used to estimate some mechanical and physical properties of rocks for many years. This study differs
from previous studies in a way that it is directly oriented to rock cuttability. Two Shore hardness values (SH
1 andSH
2) and a coefficient of deformation value (K) have been measured for 30 different rock samples. In the first stage of the study, optimum specific energy values for 16
different rock samples obtained from full-scale cutting tests were correlated with the Shore hardness values of the same rock
samples changingSH
1 values from 9 to 66 andSH
2 values from 25 to 83, with deformation coefficient values changing from 26 to 195. In the second stage, the performance of
a roadheader used in the Kü?üksu (Istanbul) tunnel was recorded in detail and the instantaneous cutting rate of the machine
was determined. Then, the relationship between Shore hardness values, deformation coefficient and the instantaneous cutting
rate of the machine was determined for different formations encountered. It is concluded that there is a relationship between
Shore hardness values, optimum specific energy and compressive strength, which may be used to estimate the rock cuttability
and the instantaneous cutting rates of roadheaders within certain limits of reliability. 相似文献
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Nurdan Günes Yılmaz 《Rock Mechanics and Rock Engineering》2013,46(1):95-106
The Equotip hardness tester (EHT) is a portable and non-destructive instrument used mainly for the dynamic rebound hardness testing of metals. Although various versions of the ‘single impacts’ and ‘repeated impacts’ testing procedures have been employed by different authors for different applications, it is not yet known whether a particular testing procedure is more relevant for a specific application in rock engineering. To be able to contribute to the subject, the present study was carried out to determine the suitability of different rebound testing procedures with this instrument for uniaxial compressive strength (UCS) estimations of some selected carbonate rocks. To achieve this goal, as well as four different existing rebound testing procedures, a newly proposed testing methodology involving the parameter hybrid dynamic hardness (HDH) was also employed. The statistical analyses performed on the experimental data, on the whole, showed that the test procedures which are based on single impacts test procedures outperformed the repeated impacts test procedures in terms of UCS prediction accuracy. The prediction capability of the newly introduced testing methodology was found to be superior to those of other procedures considered in this work, suggesting that it could be an efficient tool in practice for preliminary estimates of rock strength. The statistical analyses also indicated that, in practical applications of the EHT using different test procedures, it may be possible to predict the UCS more accurately when apparent density data is available. For the range of specimen sizes considered, no clear evidence of size effect was observed in the mean rebound values. The argument raised by some other authors that the EHT might not be a convenient instrument for the dynamic rebound hardness determination of relatively high-porosity rocks was not confirmed in this study. 相似文献
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A Discrete Element Model for Predicting Shear Strength and Degradation of Rock Joint by Using Compressive and Tensile Test Data 总被引:1,自引:1,他引:0
A discrete element model is proposed to examine rock strength and failure. The model is implemented by UDEC, which is developed for this purpose. The material is represented as a collection of irregular-sized deformable particles interacting at their cohesive boundaries. The interface between two adjacent particles is viewed as a flexible contact whose constitutive law controls the material fracture and fragmentation properties. To reproduce rock anisotropy, an orthotropic cohesive law is developed for the contacts, which allows their shear and tensile behaviors to be different from each other. Using a combination of original closed-form expressions and statistical calibrations, a unique set of the contact microparameters are found based on the uniaxial/triaxial compression and Brazilian tension test data of a plaster. Applying the obtained microparameters, joint specimens, made of the same plaster, are simulated, where the comparison of the obtained results to laboratory data shows a reasonable agreement. 相似文献