Sleeve-spliced rock direct tensile test device and method

Abstract

The invention discloses a sleeve-spliced rock direct tensile test device and method. The test device comprises a sleeve assembly, a splicing device and a tensile positioning device which are matched, wherein sleeves is adhered to end faces and a part of sides of a rock test piece, the tension capacity of the end part of the test piece is effectively improved through increasing the adhered area of the end parts of the test piece, and thus the purpose of performing a high-strength rock tensile test is reached. The test device is simple in structure, convenient to dismantle, and easy to operate, and is simple and convenient. The test device and method are easy to popularize and has a wide application prospect and remarkable economic benefit.

Description

technical field [0001] The invention relates to a rock tensile test technology, in particular to a sleeve bonding rock direct tensile test device and a test method. Background technique [0002] It is well known that rocks are mostly subjected to compressive stress and less to tensile stress. Therefore, attention is paid to the state of compressive and shear stress, and the experimental research on rock mechanical properties mainly focuses on the mechanical response of rock under compressive stress, including uniaxial, biaxial and triaxial compression tests, etc.; There are relatively few studies on mechanical properties. But at present, the stress state in engineering rock mass is often very complicated, some areas are in the state of compressive stress, while some areas are in the state of tensile stress or tensile shear stress; and the most remarkable feature of rock materials is that the tensile strength is much smaller than the compressive strength , so the failure of...

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Problems solved by technology

[0005] (1) "Metal Mine" No. 3, 1995 introduced a clamping device named SX-1, which is equipped with a universal joint, which can eliminate the eccentricity of the specimen when stretched, but the clamping device directly Connected to the end of the test piece, it is easy to have stress concentration at the clamping part, resulting in damage to the end of the test piece

[0006] (2) "Journal of China University of Mining and Technology" No. 3, 1999 introduced a direct uniaxial tensile test method. This method uses special-shaped fixtures and rock specimens. The shape of the specimen is complex and difficult to process, so it is not easy to popularize. use

[0007] (3) "Engineering Investigation" No. 4, 2011 introduced a test device for direct stretching of rocks. The upper and lower sides of the device are equipped with steering mechanisms, which can eliminate the eccentricity during the test process. The pull-down head is bonded, and the strict alignment between the specimen and the upper and lower pull-down heads cannot be guaranteed during bonding

In the above two methods, the specimen is directly connected to the testing machine, and there is no steering mechanism, so the eccentric tension of the rock specimen cannot be avoided during the test.

[0009] (5) "Journal of Rock Mechanics and Engineering" No. 3, 2005 introduced a test method for direct stretching of rocks, designed a tension-compression converter by itself, and bonded the specimen to the tension block with 504 advanced universal adhesive In the above, the rock specimen is processed by a grinding machine, but there is no steering mechanism, which still cannot completely eliminate the influence of eccentricity

[0010] (6) "Journal of Henan Polytechnic University" No. 4, 2006 introduced a direct stretching test device that can add confining pressure. This device uses glue to bond the test piece with the upper and lower pullers, but there is no steering mechanism , the effect of eccentricity cannot be eliminated

[0011] (7) "Rock and Soil Mechanics" No. 1, 2008 introduced a test device that can perform compression and direct tension tests on the same rock sample. The test device is equipped with steering mechanisms at both upper and lower ends to eliminate eccentricity. However, there is no guarantee that the test piece will be strictly centered when it is bonded to the upper and lower sliders

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