A sample wave velocity measuring device for impact test and its test method

Abstract

The invention discloses a sample wave velocity determination apparatus for split Hopkinson pressure bar impact test. The apparatus comprises a confining pressure table, an oil pressure chamber is arranged on the confining pressure table, a confining pressure station for accommodating and fixing a test block is arranged in the oil pressure chamber, a pair of mirrored wave velocity determination devices are also arranged on the confining pressure table, every wave velocity determination device comprises a sleeve hinged to the confining pressure table and two ultrasonic probes, and the ultrasonicprobes of the two wave velocity determination devices at two sides clamp the test bock to complete the sample wave velocity determination test. The invention also provides a test method using the sample wave velocity determination apparatus. The method mainly includes the steps of confining pressure and testing. The apparatus and the method avoid the inconvenience in repeated loading and unloading of the test block during the test, save time and manpower, and greatly improve the test precision and the test efficiency.

Description

technical field [0001] The invention relates to an auxiliary device for judging the structural characteristics and mechanical properties of a test block, in particular to a sample wave velocity measuring device for a separate Hopkinson compression bar impact test and a test method thereof. Background technique [0002] In recent years, with the continuous development of the world's economic construction, the buried depth of engineering rock mass has also continued to increase. Among them, the buried depth of core protection projects such as the North American Aerospace Defense Command has reached more than 700m, and the deep geological treatment depth of nuclear waste has reached hundreds of meters. Even thousands of meters, the mining energy mining project has reached a depth of more than three or four kilometers. [0003] In the construction process of deep underground engineering, the rock mass near the working face is often disturbed by the blasting of construction excav...

AI Technical Summary

Problems solved by technology

[0005] The existing separate Hopkinson pressure bar test device has the following obvious shortcomings in the research on the failure and damage of rock mass structure during the impact load process under the high ground stress environment: (1) before each measurement of the wave velocity, the It is necessary to release the oil pressure in the confining pressure table first and then disassemble the test block, and sometimes the same test block will be impacted and tested multiple times due to research needs, which requires repeated loading and unloading of the test block. The above process wastes too much unnecessary Time and manpower; (2) Repeated cycles of high surrounding rock stress loading and unloading process will lead to changes in the structural characteristics of the rock mass, so there will be a large deviation between the ultrasonic testing results and the actual situation, which will greatly reduce the test accuracy

To sum up, the existing test devices cannot effectively measure the structural characteristics and mechanical properties of rock mass during the impact test under high ground stress environment, and a new type of separate Hopkinson compression bar impact test under high confining pressure is urgently needed. The Proposal of the Sample Wave Velocity Measuring Device

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