Large three-dimensional detachable similar simulation experiment device for drilling cuttings

Abstract

A large three-dimensional detachable similar simulation experiment device for drilling cuttings comprises a detachable counter-force frame, a top hydraulic loading oil cylinder set, a side hydraulic loading oil cylinder set and a rear dynamic load loading oil cylinder. Hydraulic loading oil cylinders in the top hydraulic loading oil cylinder set and the side hydraulic loading oil cylinder set can be independently loaded so as to realize simulation of a crushing area, a plastic area and an elastic area; a horizontal dynamic load is independently applied through rear dynamic load loading oil cylinders to simulate the influence of dynamic disasters such as mine earthquakes on the stress and strain of the coal rock mass, so that the credibility of an experimental result is improved; through independent loading of a plurality of hydraulic loading oil cylinders, a drilling cutting experiment and a drilling pressure relief experiment with a coal seam inclination angle can be carried out, the outermost side of a loading cushion block extends to the outside of a sample, and a boundary effect can be effectively avoided during loading so as to reduce experiment errors; and the whole experimental device forms a three-dimensional structure, ground stress is simulated more accurately, and the accuracy of similar simulation experimental results of drilling cuttings and drill hole pressure relief is further improved by adopting a large-size sample.

Description

technical field [0001] The invention belongs to the technical field of coal mine safety, in particular to a large-scale three-dimensional detachable drilling cuttings similar simulation experiment device. Background technique [0002] By drilling small-diameter boreholes into the coal body, according to the change law and dynamic phenomenon of the powder discharge per unit depth during the drilling process, the degree of stress concentration, peak value and position of the coal body can be understood, and the risk level of rock burst can be determined to achieve rock burst. For pressure prediction purposes, the above method is the cuttings method. Because the drilling cuttings method can detect multiple factors related to rock burst at the same time, and is simple and easy to implement, it has become the most widely used method for monitoring the local stress of dynamic disasters in coal mines. The relationship between coal mass and stress is the basis of cuttings method re...

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Problems solved by technology

At present, most of the existing drilling cuttings experimental devices stay in the stage of axial compression loading, lateral restraint, and calculation of equivalent stress, and the size of the experimental devices is often small, resulting in differences in the actual conditions of the coal and rock in the experimental device. Larger, so the conclusions and laws drawn from the experiment cannot truly reflect the situation on site

[0006] For the existing drilling cuttings test device, there are still the following disadvantages: ①. The loading method of the combination of the top jack and the loading steel plate is used, resulting in a large force on the jack head and a small force on the outer edge, so the loading is uneven , and when the rock formation at the loading surface bends and sinks, the loading rigid plate cannot follow up, so that the force at the sinking position can no longer be added, and stress concentration will occur at the sinking edge; ②, for traditional large For the experimental device, a large loading area is required, and in order to better provide the loading reaction force, the frame shell of the experimental device generally adopts an integral casting structure, and the experimental device cannot be moved, so it is impossible to conduct off-site experiments; ③, Traditional experimental devices usually use a plane strain model to simulate roadway excavation and coal seam mining, so they do not have the conditions to carry out drilling cuttings experiments, and do not have the conditions for visual observation of the drilling pressure relief effect

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