Multifunctional rock shearing test testing device and testing method thereof

Abstract

The invention relates to a multifunctional rock shearing test testing device. According to the device, a vertical jack is installed at the top of a framework, and a horizontal jack and a vertical support sliding base are respectively arranged on the two opposite side walls of the framework; a horizontal support sliding base and a horizontal guide sliding rail are arranged at the center inside the base in sequence; a lower bonding box and an upper bonding box are installed above the horizontal support sliding base; a standard rock sample is arranged between the upper and lower bonding boxes; a horizontal piston rod of the horizontal jack is horizontally arranged and is equal to the lower bonding box in height; the bottom of a vertical piston rod of the vertical jack is fixed on the top surface of a vertical connecting piece; the horizontal jack, the vertical jack and the upper and lower bonding boxes are all connected with a servo control system. The testing device can be used for acquiring an accurate and perfect rock constitutive model rapidly and effectively, and establishing a corresponding strength criterion, and has important significance. The invention also discloses a testing method of the test testing device.

Description

technical field [0001] The invention belongs to the field of geotechnical testing in geotechnical engineering technology, and relates to a rock multifunctional shear test testing device, and also relates to a testing method of the testing device. Background technique [0002] The shear test of rock under compression conditions is the basic method to obtain the peak shear strength and residual strength of rock under different normal pressures, and it is also an important means to obtain the shear strength parameters of rock. Therefore, it has been widely used in geotechnical engineering, and different compression-shear test equipment has been developed. Common equipment includes large direct shear instruments used in laboratory tests and small portable direct shear instruments used in field in situ tests. [0003] As for the shear test of rock under tensile conditions, there are few reports in domestic and foreign literature, and there are few instruments and equipment that ...

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Problems solved by technology

[0005] For the traditional Mohr-Coulomb strength criterion, it is generally simplified to a linear expression for the convenience of application, that is, the shear strength of rock is a linear function of the normal compressive stress, and the normal stress becomes the tensile stress (that is, the stress on the horizontal axis negative semi-axis), the usual practice is to extend the fitted straight line on the positive semi-axis to the negative semi-axis as the strength criterion of the rock under tensile stress, which lacks the support of experimental data

Moreover, experiments have proved that under different normal pressures, the envelope of rock shear strength is not completely linear, and the slope of the tangent line corresponding to each experimental point on the envelope gradually decreases, while for the negative semi-axis at There is no unified statement about the strength envelope under different tensile stresses. The main reason is the lack of support from experimental data.

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