SU1587381A1 - Method of testing rocks for creep - Google Patents

Abstract

This invention relates to a testing technique and can be used to test rocks for creep. The purpose of the invention is to improve the accuracy of the tests. The rock specimen is loaded first with a vibration load (time interval T 0≤T≤T 2) with a maximum stress value σ max. Upon reaching the stage of steady-state vibrational creep (time interval T 1≤T≤ T 2), a short-term test (time interval T 2 ≤≤T 3) is carried out from the time T 2 of the test for a creep on the same sample at a stationary load corresponding to a stress σ Max. When a specimen is loaded, its deformation and the strain rate at unsteady and steady-state creep are measured. The coefficient of vibration acceleration of creep is determined with respect to K y = V w / V s, where V c is the speed of steady-state creep (in the interval T 1≤T≤ T 2), and V c is the speed of steady creep under stationary loading. The combination of vibration and stationary tests on a single sample in a specified sequence improves the accuracy of determining the values of V в, V с and K y. 1 il.

Description

This invention relates to a testing technique and can be used to test rocks for creep.

The purpose of the invention is to improve the accuracy of the tests.

The drawing shows the stress variation program while testing for creep and the corresponding creep pattern in the coordinates of deformation e - time t.

The method is carried out as follows.

The rock sample is loaded first with a vibration load (time interval) with a maximum voltage value equal to C1 ". Upon reaching the stage of established vibratory creep (time interval)

From the moment of time ta, a short-term (time interval) creep test was carried out on the same specimen at a stationary load corresponding to a.

When a specimen is loaded, its deformation and the strain rate at unsteady and steady-state creep are measured.

The coefficient K is determined. Vibration acceleration of creep in terms of ratio Ky Ve / Vt, where V is the speed of the established vibration creep (in the time interval); V is the steady-state creep rate at stationary loading.

Combination on one sample of vibration and stationary tests in UKSL

CO 00

zonal sequence improves the accuracy of determining the values of, H and the coefficient K.

Example. Samples with a diameter of 30 mm and a height of 70 mm of aleurite |) marl are tested with durability at one (3 MPa compression and elastic modulus 330 MPa, volume density 1.92 g / cm and humidity 26). , 2%. Frequency of changes in V1 of the loading load of 8 1 / s at the maximum and minimum pressure on the circumference equal to 1.77 and 0.05 MPa. The coefficient of vibration acceleration is., L-YuM / H / 0.776- 10 1/4 C 143.6.

Claims (1)

Formula of Invention The method of testing rocks for creep, according to which the rocks are loaded with a vibration load. deformation and strain rate are measured at stages of unsteady and steady-state creep of the rock and by comparing them with the results of short-term tests for rock creep under stationary loading, the coefficient of vibration acceleration of creep is determined, in order to increase the accuracy of the tests, vibration creep test is carried out for a short period of time at steady load on the same specimen with a load equal to the maximum cheniyu vibration load measured speed Vj of steady-state creep under stationary loading, and the coefficient K of vibratory acceleration of creep is determined by the ratio / Vc, where Ve is the rate of vibrational creep at the steady-state stage.  max tmn crawled