Rock three-point bending fixture for size effect tests

Abstract

The invention discloses a rock three-point bending fixture for size effect tests. The rock three-point bending fixture includes a pressure head section and a supporting section arranged on the lower part of the pressure head section, the pressure head part includes a pressure head body and a pressure roller, and the pressure roller is arranged at the bottom of the pressure head body; and the supporting part includes supporting rollers, moving supports, a base, and a guide rail platform, the moving supports are arranged at the two ends of the guide rail platform correspondingly, the moving supports are connected with the guide rail platform through the base, the supporting rollers are further arranged on the moving supports, and the moving supports are arranged symmetrically on the guide rail platform using the pressure head body as the center. The rock three-point bending fixture for the size effect tests can be adapted to the rock three-point bending tests with various sizes by changing the pressure roller and the supporting rollers, and the three-point bending tests of each group of test pieces with the large size change are conducted on the fixture.

Description

technical field [0001] The invention relates to the field of geotechnical engineering detection, in particular to a rock three-point bending fixture used for size effect testing. Background technique [0002] With the rapid development of my country's economic construction, the scale of geotechnical engineering is increasing day by day, and the problems of rock mass stability and deformation are becoming more and more prominent. As one of the most important mechanical characteristics of rock, tensile strength sometimes has a decisive impact on the stability of the project. The overall instability and damage of many geotechnical engineering originates from local tensile fracture. In actual engineering, rocks often exist Similar to the tension and bending stress state of beams and plates. At the same time, according to the view of fracture mechanics, the cracking of geotechnical engineering structures is mainly caused by its insufficient fracture toughness. Therefore, the st...

AI Technical Summary

Problems solved by technology

The tensile strength and fracture toughness of the rock can be effectively tested through the three-point bending test of the rock with prefabricated cracks. However, the original fixture of the universal testing machine purchased in the laboratory is for large-scale specimens. The size is too large to meet the test requirements of small size specimens

At the same time, the size of the supporting roller and the pressing blade limits that the fixture can only be applied to specimens of a single size or similar in size, and cannot meet the bending tests of various groups of specimens with large size changes at the same time.

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