Uniaxial compression strength

Table 15.1. Unconfined Uniaxial Compressive Strengths for Samples Treated with sc C02 Compared with Untreated Samples (water/cement ratio = 0.6 treated 2 h at 275.8 bar,...

Table 41 Uniaxial Compressive Strength Retention Characteristics of Epoxy and Wax Matrices Filled with Glass Microbubbles (7)...

The Yellow Brumunddal Sandstone is a Triassic, predominantly aeolian sandstone, with pronounced anisotropic properties, and with feldspar that has been weathered to clay. The average porosity is 14%, and the matrix permeability varies between 3.8 mD (perpendicular to bedding planes) and 35 mD (parallel to bedding planes). The average uniaxial compressive strength is 19 MPa. 

In Fig. 18 all cross-flow results from YBS, RWS and LC have been combined in one plot. This is done under the simplifying assumption that the combined effect of factors such as porosity, grain geometry, mineralogy and cementation on the rock strength can represented by the uniaxial compressive strength a, and therefore the normalization procedures applied (o /a and KJK ) allow comparison of results from different rock types. Because of the limited data set available, the only conclusion drawn from Fig. 18 so far, is that the KJK ratio seems to reach minimum values when the effective fracture normal stress approaches two times the uniaxial strength of the intact rock.. 

The finely crystalline zeolitic matrix of tuffs cements the other non zeolitic particles and is responsible for the overall mechanical properties of the material. The compactness and the consequent physical-mechanical properties are somewhat variable as they are function of various parameters, such as mineral composition, tuff genesis, and original conditions of the deposit, especially as regards looseness of the parent material, grain size distribution, and others. Table 3 summarizes some data on unit weight, y, porosity, P, and uniaxial compressive strength, a, of a few tuff samples and other stone materials. 

The geometric information of the fracture sets is mainly obtained from Keusen et al. (1989). Table 3 shows the data used in this analysis. The uniaxial compression strength is set at the average of the values indicated in UPC (1999). JCS is assumed to be 80% of the uniaxial compression strength. 

JCS) values were used to represent the range of mechanical properties observed in all three formations (Formation 1 see Blum et al. 2(X)3 Formation 2 JRC (/- ) = 4.28, 5.98, 4.18, 2.29 JCS (1-4) = 39.3. 31.9, 90.9, 43.1 in MPa and the unchanged uniaxial compressive strength for all 4 cases UCS = 120.0 MPa Fault Zone JRC = 4.22, JCS = 105.9 MPa and the UCS = 128.4 MPa). In case of Formation 2 only four pairs were available, thus the entire data set is provided here. Stress conditions corresponding to five depths were also applied to the DFN. Table 1 summarizes the hydro-mechanical modelling results in terms of the median hydraulic apertures. Values range between 0.3 pm and 180.7 pm. 

Variations in uniaxial compression strength versus variations In water content... 

As in the case of the Young s modulus, uniaxial compression strength increases as the degree of saturation decreases (figure 5a, figure 5b). Three phenomena are involved in the... 

Figure 5. Desiccation effects on the elastic properties of the argillites. 5a). Evolution of the uniaxial compression strength versus water content, 5b). ). Evolution of the maximum strength oftriaxial compression tests versus water content...

Rock stratum Thickness Bulk modulus of elasticity Elastic shear modulus Gravity density Angle of internal friction Cohesion Uniaxial compressive strength Uniaxial tensile strength... 

Mechanical parameters of the main coal seam have obtained to evaluate for engineering geological condition, select for support methods and provide the basis parameters for optimization of working face. The test parameters include coal and rock density, uniaxial compressive strength, uniaxial tensile strength, elastic modulus and Poisson s ratio, these results are shown in Table 1. 

A value is considered effect factor of rock mass stability under high stress condition in Mathews diagrammatize method. A value is a ratio of uniaxial compressive strength and maximum principal stress of parallel working face with complete block of coal and rock. The relationship of A value and shows a linear, and its variation range is from 0.1 to 1.0. 

The uniaxial compressive strength of all the POP specimens were determined under unconfined conditions, using a 5 tonne capacity loading fiame as per ISRM (1977) and IS 9143 (1979). 

POP mixed with 10% Portland cement by weight was also used to prepare cylindrical specimens to have relatively higher uniaxial compressive strength and to represent higher wall strength, in case of jointed specimens. A total of 110 gm mixture was taken containing 11 gm Portland cement and was thoroughly dry mixed with a stirrer. This POP with cement mix was then mixed with specific quantity of water (always kept constant for every sample) to cast cylindrical specimens with split moulds similar to POP without cement mix specimens. These specimens of POP with ce-... 

UNIAXIAL COMPRESSIVE STRENGTH/ELASTIC MODULUS OF JOINTED ROCKS... 

It is attempted to evaluate uniaxial compressive strength (UCS) and elastic modulus of rock mass as a function of UCS or elastic modulus of intact rock and j oint factor. Figure 14 shows the variation of (the ratio of UCS of jointed rock to the intact rock) with joint factor (Jj.) for tested material. The term joint factor (Jj.), introduced by Ramamurthy (1993), which reflects the combined effect of j oint frequency, joint inclination and joint roughness (or wall strength) and is expressed as ... 

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