A fixture and assembly method for unloading a two-rigid and one-soft true triaxial testing machine

Abstract

The invention relates to a fixture for unloading of a two-rigid one-flexible true triaxial tester and an assembly method of the fixture. The fixture comprises four press blocks, wherein the four pressblocks are respectively a first press block, a second press block, a third press block and a fourth press block, position control posts are arranged in grooves of the first press block, the second press block, the third press block and the fourth press block, the grooves of the first press block, the second press block, the third press block and the fourth press block are connected in an end-to-end way to form a square groove, a limitation baffle plate is arranged in the limitation baffle plate, and four surfaces of the limitation baffle plate is attached onto a surface of the control post. By the fixture, the defect of the fixture of the two-rigid one-flexible true triaxial tester in unloading experiment is made up, single-surface unloading can be achieved when the fixture is used for performing unloading experiment in a single direction, the limitation baffle plate can have a certain limitation constraint effect on a rock sample on the other surface corresponding to the limitation baffle plate, so that the damage behavior of the rock during the unloading experiment process can be more widely researched, and possibility is also provided for researching unloading destruction disaster of an engineering site.

Description

technical field [0001] The invention belongs to the technical field of rock sample fixtures for true triaxial testing of rocks, and in particular relates to a fixture and an assembly method for unloading a two-rigid-flexible true triaxial testing machine. Background technique [0002] In order to meet the needs of the rapid development of today's society, many large-scale water conservancy and hydropower, mining and geotechnical construction projects have gradually entered the deep part of the earth. At the same time, the disasters of engineering rock mass (especially hard and brittle rock mass) induced by deep high geostress not only cause huge economic losses to the project, but also pose a threat to the personal safety of workers. The failure of engineering rock mass under deep high geostress environment, especially at the excavation boundary, often results in cracking and failure due to excavation and unloading. The rocks in the crust are mostly in the true triaxial str...

AI Technical Summary

Problems solved by technology

However, for the "two rigid and one flexible" type true triaxial testing machine, the oil pressure direction is generally the direction of the minimum principal stress. When unloading the test, the rock sample can only be unloaded on both sides in the oil pressure direction. Unable to unilaterally restrict the rock sample in the direction of the minimum principal stress, this undoubtedly has certain limitations on the study of rock unloading failure behavior, which is not conducive to the study and analysis of disasters such as slabs and rockbursts from a more general situation mechanism

In addition, there are almost no fixtures for single-sided unloading tests in the "two rigid and one flexible" type true triaxial testing machines in China, and the cost of changing the type of testing machine is much higher than the cost of inventing new fixtures

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