Rock sample sealing method for hard rock true triaxial test

Abstract

The invention relates to a rock sample sealing method for hard rock true triaxial test, and belongs to the technical field of the hard rock true triaxial test. By additionally arranging groove chamfer angles at edges of pressure-bearing blocks and additionally arranging a step slot at a contact surface of every two adjacent pressure-bearing blocks, and at the same time, making the thickness of each pressure-bearing block larger than that of a rock sample, uniformity of a glueing layer can be well controlled by the difference between the thickness of the pressure-bearing block and the rock sample. Seal glue at the groove chamfer angles completely cover gaps on the contact surfaces of the pressure-bearing blocks and the rock sample, so that the glueing layers of the gaps on the contact surfaces are prevented from cracking and microosmolarity of an oil liquid at weak points of the glueing layers is prevented. By additionally arranging sealing rubber strips in the step slots, adequate seal between gaps on the contact surface of two adjacent pressure-bearing blocks can be achieved; and the sealing rubber strips are coated by seal glue, thereby playing a role of double seal. The method reduces influences of oil liquid leakage on test results to the lowest, thereby increasing accuracy and reliability of test data.

Description

technical field [0001] The invention belongs to the technical field of hard rock true triaxial tests, in particular to a rock sample sealing method for hard rock true triaxial tests. Background technique [0002] In order to accurately reflect the mechanical properties of rock under natural stress, it is necessary to provide effective and accurate test data for rock instability in the actual deep mining process through hard rock true triaxial tests, and to guide actual production through test data. [0003] During the true triaxial test of hard rock, there are many factors that affect the accuracy of the test data, among which the tightness of the rock sample is an important one, and the quality of the tightness directly affects the success or failure of the test. Because there are a lot of voids and fissures inside the rock sample, under the true triaxial stress state, the small principal stress direction is affected by the oil pressure. Once the oil enters the inside of th...

AI Technical Summary

Problems solved by technology

Because there are a lot of voids and fissures inside the rock sample, under the true triaxial stress state, the small principal stress direction is affected by the oil pressure. Once the oil enters the inside of the rock sample, the stress between the pores will change. Thereby changing the true effective stress of the rock sample, and the oil intrusion also destroys the uniformity of the small principal stress, thus affecting the stress state of the large and medium principal stress; moreover, after the oil directly contacts with the rock sample , the oil will intrude into the rock sample through the cracks. At this time, some physical and chemical changes may occur in the composition of the rock sample, which will lead to changes in the properties of the rock sample, thereby affecting the post-peak behavior of the rock sample. Ultimately, the true post-peak characteristic curve and residual strength cannot be obtained

[0004] At present, in the traditional rock sample sealing method, the height of the pressure-bearing block is equal to the height of the rock sample, and then the rock sample is clamped by the pressure-bearing block, and then the rock sample is sealed in the small stress direction before and after the rock sample. The surface is coated with sealant separately, but this method of coating can easily cause the uniformity of the coating layer to deteriorate, the thickness of the coating layer is difficult to control, and the oil is easy to form micro-seepage in the weak part of the coating layer; the pressure pad When the blocks slide relative to each other, the adhesive layer at the joint between the pressure pad and the rock sample is easily broken, and between the contact surfaces of two adjacent pressure pads, at the same time under high oil pressure In this state, zero penetration of the oil cannot be achieved at all, and the existing sealing method cannot realize the sealing between the contact surfaces of two adjacent pressure pads, which leads to the fact that under the traditional sealing method, the test data are all It is obtained after the oil penetrates into the rock sample, which greatly reduces the accuracy and reliability of the test data, and can also guide the actual production through these test data

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