The uniaxial compressive strength, elastic modulus, point load strength, Schmidt hammer value, P-wave velocity, density and porosity values of the samples were determined in the laboratory.

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Uniaxial compressive strength ( ... Granite 154 48 313 71 169 42 250 20 Granodiorite 160 51 319 2 171 20 118 2 Gabbro 228 106 466 5 248 76 306 1 Norite 229 82 356 8 - - - - Olivinestone - - - - 87 113 1307 5 Peridotite 197 55 280 1 109 164 1502 1 Monzonite 110 28 256 8 106 61 580 4 ...

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Keywords: soft rock, uniaxial compressive strength, physical characte ristic, point load strength index, and conversion factor. INTRODUCTION strength due to changes in moisture content seems The term soft rock is often referred to rock materials with a uniaxial compressive strength (UCS) lower than that of hard rocks and higher than that of soils.

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Uniaxial Compressive Strength (UCS) defines mechanical strength of the intact rock material and it is one of the most used parameters in rock engineering. In the laboratory, it is determined by uniaxial compression on circular cylinder specimens according to standardized test procedures [1, 2].

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In particular, the Uniaxial Compressive Strength is re-calculated as: σ c = σ UCS / (0.88 + 0.222*(D/L) ) Where σ c is the corrected uniaxial compressive strength. Rock characterization and typical range of UCS based on rock types . Based on their Uniaxial Compressive Strength, rocks can be characterized from very weak to very strong as ...

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Posted: (6 days ago) Jun 21, 2018 · The compressive strength of granite (depth = 1377–2002 m) taken from GPK-1 (see Fig. 1 for location) was found to range between 120 and 485 MPa at a confining pressure of 40 MPa (Rummel 1992), and uniaxial compressive strength (UCS) values between 100 and 130 MPa are reported for unaltered granite from ...

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To investigate the uniaxial compressive behavior of the granite under high strain rates compression, three groups of specimens with the same aspect ratio (0.5) but different diameters were tested ...

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Figure 4: (a) Compressive strength for all 16 tested granite samples. (b) Average compressive strength obtained from uniaxial and triaxial (b) Average compressive strength obtained from uniaxial ...

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In order to study the uniaxial mechanical properties and failure modes of granite under the condition of thermo-liquid coupling, the granite was subjected to thermo-liquid coupling cyclic treatment at different temperatures, and then its mechanical properties were analyzed by uniaxial compression test. The results reflect the following trends: (1) the stress–strain curve generally …

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STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES 1. INTRODUCTION 2. TESTING OF INTACT ROCK FOR STRENGTH 2.1 Uniaxial Compression 2.2 Point Load Testing 2.3 Uniaxial Tension 2.4 Indirect Tension Tests 2.5 Shear Tests 2.6 Confined Compression Tests (Triaxial Tests) 2.7 Biaxial and Multiaxial Tests 2.8 Other Tests 3. PARAMETERS AFFECTING ROCK STRENGTH 4.

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In this paper,the TAW-2000 servo triaxial testing machine and acoustic emission testing equipment are used to analyze the characteristics of granite under uniaxial compression at 25~650℃ after high temperature. The variation rules of longitudinal wave velocity,maximum strength and AE counts with time are analyzed respectively. The results show that the P-wave velocity and the maximum ...

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Rebound hammer test is widely used as an indirect measure of uniaxial compressive strength for engineering materials such as concrete, soil, and rock in both civil and mining engineering works. In quarries, uniaxial compressive strength is a crucial parameter in the analysis of geotechnical problems involving rock stability and rock blasting ...

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Most of these studies considered the uniaxial compressive strength of the granitic rocks as an indicator for the suitability of the granitic rocks in industrial use for determination of the degree of weathering. For this reason, the practical determination of the UCS of granitic rocks is highly important for rock engineering work.

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2.1 Classification of rocks on the basis of uniaxial compressive strength 15 2.2 Correlation between UCS and Is 17 3.1 Coring Machine 22 3.2 Rock disc cutter 23 3.3 Lapping machine 24 3.4 Samples of limestone and granite prior to testing of uniaxial compressive strength 24 3.5 Tinius Olsen Super "L" Hydraulic Universal Testing Machine 26

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Table 11.2: Field estimates of uniaxial compressive strength. Grade* Term Uniaxial Comp. Strength (MPa) Point Load Index (MPa) Field estimate of strength Examples R6 Extremely Strong > 250 >10 Specimen can only be chipped with a geological hammer Fresh basalt, chert, diabase, gneiss, granite, quartzite R5 Very strong 100 - 250

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Uniaxial and triaxial compressive experiments were conducted on intact and single- and double-flawed granite specimens using MTS 815 electrohydraulic servo-controlled triaxial testing system to understand further the influences of confining pressure and fracture on rock strength and failure mode.

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Compressive strength of rocks PetroWiki. Jun 04, 2015· Estimating compressive strength. General rock failure criterion can be reduced to a few parameters dependent on lithology (m) and the uniaxial compressive strength (C 0).Lithology is commonly derived during log analysis, so m may be estimated (Table 1).What is needed still is an initial measure of rock strength provided by C 0.

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STRENGTH PROPERTIES OF ROCKS AND ROCK MASSES 1. INTRODUCTION ... TESTING OF INTACT ROCK FOR STRENGTH 2.1 Uniaxial Compression ... Granite Basalt Gneiss Schist ... test method for unconfined compressive strength of intact rock core

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Estimating compressive strength. General rock failure criterion can be reduced to a few parameters dependent on lithology (m) and the uniaxial compressive strength (C 0).Lithology is commonly derived during log analysis, so m may be estimated (Table 1).What is needed still is an initial measure of rock strength provided by C 0. C 0 can be estimated from porosity or sonic velocities, but …

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Uniaxial compression tests have been conducted on Oshima granite under various constant axial strain rates ranging from 10 −8 to 10 −4.The results showed that the strength and the acoustic emission rate increased exponentially with increasing strain rate.

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(a) Compressive strength for all 16 tested granite samples. (b) Average compressive strength obtained from uniaxial and triaxial tests; uniaxial testing data from published literature. (c) Uniaxial compressive strength under monotonic and cyclic loading.

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A total of 70 and 24 ultrasonic and uniaxial compressive strength tests have been conducted on the granite and schist respectively. Figures 4 and 5 show the laboratory results of granite and schist plotted against the established empirical relationships between uniaxial compressive strength (UCS) and ultrasonic velocity travel time (t p)

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Eight granite samples (#1–#8) are used for uniaxial testing. #1–#3 are monotonically loaded with a rate of 2 mm/min. The axial stress rate approximately ranges between 0.15 and 0.25 MPa/s. Monotonic quasistatic uniaxial tests are performed to determine the uniaxial compressive strength (UCS) of the granite samples.

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Fissures have a great influence on the strength of granite in a uniaxial compression test. It is obvious that the compressive stress exhibits an approximately linear upward relation with increasing α in the range from 30 to 60° (as shown in Figure 3 ).

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For the uniaxial or unconfined compressive strength test a right circular cylinder of the material is compressed between the platens of a testing machine as illustrated in Fig. 8.1. The compressive strength is then defined as the maximum load applied to crush the specimen divided by …

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Normal variation of compressive strength and the factor m in Hoek-Brown failure criterion for some rocks (data from Hanssen, 1988; Hoek and Brown, 1980 and Hoek et al., 1992). Rock name Uniaxial compressive strength c Rating of the factor Rock name Uniaxial compressive strength c factor Rating of the low average high m i

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Abstract: Uniaxial Compressive Strength (UCS) is the most important parameter that quantifies the rock strength. However, determination of the UCS in the laboratory is very expensive and time-consuming. Therefore, common index tests like point load (Is -50), ultrasonic velocity test (V P), block punch index (BPI)

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strength reduction in all weathering grades are not so obvious since all specimens show variation of strength reduction from 5 % to 15 %. Then it can be deduce that 50% amplitudes of cyclic loads could reduce uniaxial compressive strength of weathered granite up to 15% average.

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This study shows that the uniaxial compressive strength of Toki granite varies significantly along the investigated boreholes. Attention was therefore focused on these variations and potential explanations. One of the factors playing a role in the variation of the intact rock strength seems to be the vicinity to the surface of the granite basement.

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Failure behavior of pillars in deep mines is affected by various cyclic loads that cause initial pre-damage. Pillars will be further damaged and developed in the long-term compressive stress until they are destroyed. To reveal the strength characteristics and crack damage fracture laws after rock pre-damage, uniaxial compression tests were carried out on granite specimens damaged by cyclic ...

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