Experimental method for simulating impact rock-burst

Patent metadata

Field	Value
Publication number	US-9316568-B2
Application number	US-201214389318-A
Country	US
Kind code	B2
Filing date	Mar 31, 2012
Priority date	Mar 31, 2012
Publication date	Apr 19, 2016
Grant date	Apr 19, 2016

Abstract

An experimental method for simulating an impact rock-burst, comprises the following steps: making a rock sample having a through hole or a half hole; loading initial static stresses of three directions onto the rock sample; then loading dynamic load(s) by 0.5-10 minutes, to determine whether a spalling phenomenon appears on an internal surface of the hole; if appears, and the rock sample is further damaged, determining and recording a failure course, if not appears, increasing the static stress(es) or the intensity of the dynamic load, then repeating the experiment procedure as far as the rock sample goes into the failure course, then determining and recording the failure course, and ending the expierment. The impact rockburst induced by dynamic load is simulated in the rock sample successfully, and by sudying mechanical mechanisms of the rock-burst, the present application lays foundations for gradually understanding and mastering the nature of real rock burst.

First claim

What is claimed is:

1. An experimental method for simulating an impact rockburst, the method comprising:
S1: making a rock sample specimen having a through hole or a half hole;
S2: loading initial static stresses of three directions onto the rock sample specimen, and maintaining the initial static stresses of the three directions, to simulate a situation that an excavated tunnel suffers the static stresses;
S3: loading dynamic load(s) of one direction, two directions or three directions onto the rock sample specimen by 0.5-10 minutes, so as to determine whether a spalling phenomenon appears on an internal surface of the through hole or the half hole, wherein the dynamic load is used to simulate the disturbance wave induced by an excavation, a blasting, an earthquake or a mechanical vibration;
S4: under an action of the dynamic load in the step S 3 , if it is determined that the spalling phenomenon appears on the internal surface of the hole, unceasingly maintaining a state of loading the dynamic load in the step S 3 by 0.5-10 minutes, to determine whether the rock sample specimen is further damaged, and if the rock sample specimen is not further damaged, stopping the loading the dynamic load, and increasing the static stress(es) of one direction, two directions or three directions loaded onto the rock sample specimen, then repeating the step S 2 and the following experimental steps, and if the rock sample specimen goes into a failure course, determining and recording the failure course, and ending the experiment of the impact rockburst; and
S5: under the action of the dynamic load in the step S 3 , if it is determined that no spalling phenomenon appears on the internal surface of the hole, unceasingly maintaining the state of loading the dynamic load in the step S 3 by 2-10 minutes, to determine whether the spalling phenomenon appears in the rock sample specimen, and if it is determined that the spalling phenomenon appears on the internal surface of the hole of the rock sample specimen, repeating the step S 4 and the following experimental steps, and if it is determined that no spalling phenomenon appears on the internal surface of the hole of the rock sample specimen, stopping the loading the dynamic load, and increasing the static stress(es) of the one direction, the two directions or the three directions loaded onto the rock sample specimen, then repeating the step S 2 and the following experimental steps, and if the rock sample specimen goes into the failure course, determining and recording the failure course, and ending the experiment of the impact rockburst.

2. The method according to claim 1 , wherein in the step S 1 , the rock sample specimen is obtained from a rock mass at a site to be excavated.

3. The method according to claim 1 , wherein in the step S 4 and S 5 , if the rock sample specimen is not damaged, after the loading the dynamic load is stopped, increasing the static stress(es) of the one direction, the two directions or the three directions loaded onto the rock sample specimen, wherein an increased amount of the static stress(es) of the one direction, the two directions or the three directions is(are) of the same intensity as that of the dynamic load loaded onto the rock sample specimen in the step S 3 .

4. The method according to claim 1 , wherein in the step S 2 , a manner of loading the static stresses is a force loading manner or a strain loading manner, wherein, when the strain loading method is adopted, a loading rate is 0.004-0.2 mm/s, and when the force loading method is adopted, the loading rate is 0.05-2 kN/s.

5. The method according to claim 1 , wherein in the step S 1 , a cross section of the through hole or the half hole in the rock sample specimen has a shape of circular, half circular, or horseshoe.

6. The method according to claim 1 , wherein in the step S 1 , the rock sample specimen is made in a joint structure, and the rock sample specimen made in the joint structure is obtained by being collected from the site and then being further processed, or made by the following steps:
(1) making up a plurality of plasterboards or resin plates, and drying the plurality of the plasterboards or the resin plates by air, wherein each of the plasterboards has a thickness of 5˜10 mm, and each of the resin plates has a thickness of 3˜8 mm;
(2) bonding the plurality of the dried plasterboards or the dried resin plates together to form a laminate body by using an adhesive, and then drying the laminate body by air;
(3) cutting the dried laminate body of the plasterboards into a required size according to a joint strike, and forming the hole at a position of a centre line of the laminate body, so as to obtain the rock sample specimen in the joint structure.

7. The method according to claim 1 , wherein in the step S 3 , a disturbance signal of the dynamic load comprises: a cyclic wave disturbance signal, a single pulse disturbance signal, a step pulse disturbance signal, a noise wave disturbance signal, or a complex wave disturbance signal formed by superposing any of the above cyclic wave disturbance signal with a slope wave, or a superposed disturbance signal formed by superposing the complex wave disturbance signal with the noise wave disturbance signal.

8. The method according to claim 1 , wherein the method further comprises a step of recording and/or a step of photographing, wherein, when the spalling phenomenon appears on the surface of the rock sample specimen, the failure course is recorded and/or photographed by using a micro camera.

9. An experimental method for simulating an impact rockburst, the method comprising;
S1: making a rock sample specimen having a through hole or a half hole;
S2: loading initial static stresses of three directions onto the rock sample specimen, and maintaining the initial static stresses of the three directions, to simulate a situation that an excavated tunnel suffers the static stresses:
S3: loading dynamic load(s) of one direction, two directions or three directions onto the rock sample specimen by 0.5-10 minutes, so as to determine whether a spalling phenomenon appears on an internal surface of the through hole or the half hole, wherein the dynamic load is used to simulate the disturbance wave induced by an excavation, a blasting, an earthquake or a mechanical vibration;
S4: under an action of the dynamic load in the step S 3 , if it is determined that the spalling phenomenon appears on the internal surface of the hole, unceasingly maintaining a state of loading the dynamic load in the step S 3 by 0.5˜10 minutes, to determine whether the rock sample specimen is further damaged, and if the rock sample specimen is not further damaged, stopping the loading the dynamic load, and increasing an intensity value of the dynamic load, then repeating the step S 3 and the following experimental steps, and if the rock sample specimen goes into a failure course, determining and recording the failure course, and ending the experiment of the impact rockburst; and
S5: under the action of the dynamic load in the step S 3 , if it is determined that no spalling phenomenon appears on the internal surface of the hole, unceasingly maintaining the state of loading the dynamic load in the step S 3 by 2-10 minutes, to determine whether the spalling phenomenon appears in the rock sample specimen, and if it is determined that the spalling phenomenon appears on the internal surface of the hole of the rock sample specimen, repeating the step S 4 and the following experimental steps, and if it is determined that no spalling phenomenon appears on the internal surface of the hole of the rock sample specimen, stopping the loading the dynamic load, and increasing the intensity value of the dynamic load, then r

Assignees

• He Manchao
• Sun Xiaoming
• Yang Xiaojie
• Univ China Mining

Inventors

• He Manchao
• Sun Xiaoming
• Yang Xiaojie

Classifications

• G01N3/30

  by applying a single impulsive force, e.g. by falling weight · CPC title

• G01N3/313 Primary

  generated by explosives · CPC title

• G01N3/02 Primary

  Details · CPC title

• G01N24/081

  Making measurements of geologic samples, e.g. measurements of moisture, pH, porosity, permeability, tortuosity or viscosity · CPC title

• G01N3/068

  with optical indicating or recording means · CPC title