Anchorage damage test device and test method for fracture surrounding rock

Abstract

The invention provides a test device and a test method for the damage of the anchorage performance of cracked surrounding rocks, and relates to the technical field of bolt support performance tests. A servo hydraulic cylinder is fixed on the frame. The servo hydraulic cylinder includes an upper servo hydraulic cylinder and a side servo hydraulic cylinder. The servo hydraulic cylinder pressurizes the damaged fracture specimen or the complete rock specimen. The connection frame and the loading frame are fixedly connected. The end of the connecting frame and the end of the annular oil cylinder are provided with anchor rod fixing fixtures. One end of the test anchor rod is fixed by the anchor rod fixing fixture, and the other end is set in the damaged crack specimen. The ground stress is simulated by the servo hydraulic cylinder, and the annular The oil cylinder pulls the anchor rod. The device and method can complete the simulation test of the influence of surrounding rock damage on the anchoring force of the bolt, test the damage evolution law of the anchoring performance of the surrounding rock with different cracks, and can also test the mechanical performance of the bolt (cable).

Description

technical field [0001] The invention relates to the technical field of bolt support performance testing, in particular to an anchorage performance damage testing device for cracked surrounding rocks, and a method for using the device for testing. Background technique [0002] The discontinuity of surrounding rock is a common problem faced in geotechnical engineering construction. In a specific geological environment, the natural rock mass is subjected to the action of geological stress, resulting in the formation of various through or non-through joint fissures inside the rock mass. This fissure structure affects the physical and mechanical properties and characteristics of the surrounding rock, and causes safety problems often encountered in mining, tunnels, and underground spaces. Numerous theoretical studies and engineering practices have shown that the instability and failure of surrounding rock in roadways are mostly related to the expansion and penetration of internal...

AI Technical Summary

Problems solved by technology

[0003] For coal mine roadways, anchor rods are mostly used to anchor the roadways at present. However, due to the complex geomechanical environment of the surrounding rocks in cracks and the many factors involved in the process and equipment involved in anchoring engineering, the research on the anchoring control mechanism of surrounding rocks in cracks is far behind. Engineering practice, anchoring engineering design mostly relies on experience and semi-empirical methods

First of all, the surrounding rocks of the fractures are mostly discontinuous bodies, and their mechanical parameters are significantly different from those of the intact rock specimens. The mechanical properties of the rock mass have weakened, and the specific parameters are not easy to determine, which brings difficulties to numerical simulation and theoretical analysis; secondly , the detection of surrounding rock fissures in the support engineering site is complicated and difficult. It is difficult to carry out long-term monitoring by using ultrasonic surrounding rock fissure detectors or double-ended plugging drilling and water injection method. The characteristics and rules of the interaction with the bolt are not easy to spy

Finally, the current research on the mechanical properties of fractured rock mass is mainly based on experimental research. Scholars at home and abroad have carried out a lot of research on jointed rock masses in the form of single cracks, double cracks and multiple cracks, and achieved a series of results; for The test of anchorage force is mostly destructive pullout test at this stage, and most of the tests do not consider environmental factors such as the real surrounding rock structure and ground stress; the test equipment for the anchorage performance of surrounding rock can generally apply surface force to the rock specimen to simulate ground stress. However, it is difficult to conduct quantitative research on the influence of primary or secondary cracks in the surrounding rock on the anchoring force of the bolt, and it does not consider the real situation of elastic-plastic changes in the rock mass under high-stress conditions, and then failure.

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