Shear test confined

The results of the drained triaxial compression shear tests with the same initial states and different temperatures (22 °C and 90 °C) are compared for several overconsolidation ratios (OCR) (Figure 2). The initial confining pressure was 600 kPa. 

Poisson s ratio has been calculated directly from tensile tests (v = 0.37-0.50) [10] and indirectly from torsional shear and confined compression creep data (v = 0.37-0.47) [6, 9]. More recently, the relationship between Poisson s ratio, n, aggregate modulus, Ha, and permeability, k, have been established for cartilage indentation testing based on biphasic (fluid and porous solid) constitutive theory [15]. Using a complex numerical solution and curve fitting scheme, Poisson s ratio can be extracted from indentation data, resulting in values of v = 0.00-0.30 [11, 12, 16]. However, care must be exercised in interpreting such indirect measures of Poisson s ratio as unexpected results can arise e.g. v = 0.0. 

Fig. 3 shows a vertical cross-section of NGI s triaxial coupled shear flow test (TCSFT) cell. This modified triaxial cell allows higher confining stresses and the testing of smaller samples compared to the CSFT cell. The tested samples had a diameter of... 

The bulk rheological properties of the PFPEs, including the melt viscosity, storage modulus, and loss modulus at several different temperatures, have been widely reported via steady shear and dynamic oscillation tests. In this entry, the focus is on the confined geometry effects on viscosity. 

In the Jenike shear cell, the failure is forced to be in a lenticular space around the horizontal shear plane rather than throughout the whole sample and shear strains cannot therefore be determined. This disadvantage is overcome to some extent in the simple shear apparatus which confines the powder specimen in a rubber membrane or a hinged box, thereby allowing the failure to occur in the whole of the sample. As the whole thing distorts during test, shear strains can be evaluated. The shear stresses are not, however, uniformly distributed and the method has not been widely used other than in research. 

Figure 2 shows the relationship between axial displacement and differential stress. Temperatures were in the range of 25 to 600°C and confining pressure and pore pressure were lOOMPa and 25MPa, respectively. The tests were performed at a constant ram displacement rate of 0.02 mm/min. It is seen that nonlinear deformation and softening behavior were observed and peak strength was reducing with increasing temperature. The fractured specimen was shown in Fig. 3. Thus, the brittle shear fracture was occurred in any case of temperature conditions. Using the fracture angle...

Figure 3. Brittle shear faulting in a compressive test of lidate Granite (Temperature 500 C, Confining Pressure lOOMPa, Pore Pressure 25MPa).

Casagrande (1936) performed a series of drain, strain-controlled triaxial tests on initially loose and initially dense sand specimens. Results showed that all specimens tested at the same effective confining pressure approached the same density or void ratio when sheared... 

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