CN115235922A - Rock sample shearing box simulating blasting vibration effect - Google Patents
Rock sample shearing box simulating blasting vibration effect Download PDFInfo
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- CN115235922A CN115235922A CN202110440661.6A CN202110440661A CN115235922A CN 115235922 A CN115235922 A CN 115235922A CN 202110440661 A CN202110440661 A CN 202110440661A CN 115235922 A CN115235922 A CN 115235922A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
- G01N3/04—Chucks
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/24—Investigating strength properties of solid materials by application of mechanical stress by applying steady shearing forces
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0001—Type of application of the stress
- G01N2203/0005—Repeated or cyclic
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0016—Tensile or compressive
- G01N2203/0019—Compressive
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0014—Type of force applied
- G01N2203/0025—Shearing
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0682—Spatial dimension, e.g. length, area, angle
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
- G01N2203/06—Indicating or recording means; Sensing means
- G01N2203/067—Parameter measured for estimating the property
- G01N2203/0688—Time or frequency
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- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention relates to a rock sample shearing box for simulating blasting vibration effect, which is provided with an upper shearing box and a lower shearing box, wherein the central part of the shearing box is provided with a cavity for placing a rock sample, and the side surfaces of the upper shearing box and the lower shearing box in the vertical shearing direction are respectively provided with a vibration signal monitoring hole and a rectangular window for placing a filter cushion block group; all offer the displacement monitoring hole in the middle part of shearing box both sides along shearing box shearing direction, all be equipped with the sensor mount on the last shearing body of every displacement monitoring hole one side. The shear box is simple in structure, scientific in design and convenient to assemble and disassemble, is suitable for rock sample compression shear tests under the effect of indoor simulated blasting vibration effect, can truly and accurately reflect the influence of different blasting vibration response main frequencies and peak speeds on rock samples, and is high in test efficiency and reliable in test result.
Description
Technical Field
The invention relates to a shearing box, in particular to a rock sample shearing box simulating an explosion vibration effect.
Background
With the large-scale development of basic construction, in the construction process of various projects, blasting operation is often required to be carried out on a rock mass, and the vibration effect generated by blasting can obviously influence the strength of the rock mass and the stability of a slope body, so that accidents such as landslide and collapse can be caused, and the research on the influence effect of blasting vibration on the mechanical strength of the rock mass has important theoretical and practical significance. At present, the influence of blasting vibration on the mechanical strength of a rock body is mainly researched in an indoor test mode, dynamic impact is carried out on a rock sample in the compression-shear test process so as to simulate the influence effect of blasting vibration, the indoor test mode has the advantages of simplicity and convenience in operation, reliable test results and the like, but the existing test device is not easy to accurately simulate and directly monitor the blasting vibration in the compression-shear test process.
The following problems mainly exist in the commonly existing shearing box: the blasting vibration signal simulation is inaccurate, namely after dynamic excitation is applied in the test process, the vibration response frequency and response speed peak value generated by the rock sample have larger difference with the actual vibration signal parameter; in the test process, the vibration response of the rock sample is not easily monitored directly, but the vibration response signals of the shearing box or other parts contacting with the rock sample are monitored, so that the error of the monitoring result is larger.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provide the rock sample shearing box for simulating the blasting vibration effect.
In order to achieve the purpose, the invention adopts the technical scheme that: the rock sample shearing box for simulating the blasting vibration effect is provided with an upper shearing box, a lower shearing box and a normal loading cushion block; the upper shearing box is formed by connecting an upper top plate and an upper shearing body by using an inner hexagon bolt; the lower shearing box is formed by connecting a lower shearing body and a lower bottom plate by using an inner hexagon bolt; the center parts of the upper shearing box and the lower shearing box are provided with cavities for placing rock samples, the normal loading cushion block is placed on the rock samples, the bottom of the normal loading cushion block is in contact with the upper end face of the rock sample, and the top of the normal loading cushion block is in contact with a power loading structure for applying normal load;
the upper shearing box is arranged in an upper shearing body vertical to the shearing direction, and the middle of one side surface of the upper shearing box is provided with a rectangular window which is used as a vibration signal monitoring hole; the middle part of the lower shearing body of the lower shearing box on the other side surface opposite to the vibration signal monitoring hole is provided with a rectangular window for placing the filtering cushion group;
the middle parts of the two sides of the upper shearing box and the lower shearing box along the shearing direction are provided with square grooves as displacement monitoring holes and observation ports for observing the rock sample shearing process; a sensor fixing frame is arranged on the upper shearing body on one side of each displacement monitoring hole;
the sensor fixing frame is composed of a base, a fixing clamp and a bolt, the base is installed on the side portion of the upper shearing body through the bolt and a bolt hole, and the fixing clamp is fixed on the base through the bolt.
The filtering cushion group consists of two or more filtering cushion blocks, pin threaded holes are formed in the center of each filtering cushion block, and the filtering cushion blocks are connected into the filtering cushion group through threaded pins and the pin threaded holes.
The combination mode of the filtering cushion block group is the combination of filtering cushion blocks made of the same material or different materials.
The sensor fixing frame is used for installing a displacement sensor, the sensor is clamped between the fixing clamp and the base, and the clamping degree of the sensor is controlled through the adjusting bolt.
The filtering cushion block can be made of metal materials such as copper, aluminum and stainless steel, or resin materials such as polyethylene and polyvinyl chloride.
Compared with the prior art, the rock sample shearing box simulating the blasting vibration effect has the beneficial effects that:
(1) according to the invention, the rock sample is placed at the central parts of the upper shearing box and the lower shearing box, the normal loading cushion block is arranged at the upper part of the rock sample, the top part of the rock sample is contacted with the dynamic loading structure for applying normal load, and the bottom part of the rock sample is directly contacted with the upper end surface of the rock sample, so that the normal load can be completely applied to the upper end surface of the rock sample, the friction force between the upper shearing box and the lower shearing box is prevented from being increased due to the normal load borne by the upper shearing body, and the test result is more accurate.
(2) The vibration signal monitoring hole is formed in one side, perpendicular to the shearing direction, of the upper shearing body of the upper shearing box, a space is reserved for mounting the sensor for monitoring the vibration signals through the vibration signal monitoring hole, the sensor for monitoring the vibration signals can be directly adhered to the rock sample in the vibration signal monitoring hole, vibration response signals of the rock sample under the excitation of impact loads can be accurately measured, and measuring errors caused by the fact that the sensor is in contact with other media are avoided.
(3) The lower shearing body of the lower shearing box is perpendicular to the middle part of the shearing direction, and a rectangular window for placing the filtering cushion block group is arranged on the other side of the vibration signal monitoring hole.
(4) The sensor fixing frames are arranged on the two sides of the upper shearing body of the upper shearing box along the shearing direction, the sensor fixing frames are arranged on the side edges of the upper shearing body, so that the displacement sensor can be ensured to be firmly clamped on the upper shearing body, and the upper shearing body is kept static relative to a test system in a test, thereby ensuring that the displacement sensor is not influenced by shearing load and vibration impact, and improving the reliability of a displacement measurement result.
(5) The filtering cushion group is formed by connecting two or more filtering cushion blocks, the filtering cushion blocks are connected by the filtering cushion blocks made of the same or different materials, the center part of each filtering cushion block is provided with a threaded pin hole, each filtering cushion block is connected by adopting a threaded pin, and the response dominant frequency of a rock sample under vibration excitation can be changed by changing the number of the filtering cushion blocks and the combination of different materials of the filtering cushion blocks during experiments, so that the simulation of the response dominant frequency of different rock samples by a test system can be realized accurately and conveniently.
(6) The shearing box is simple in structure, scientific in design and convenient to assemble and disassemble; the shearing box is suitable for rock sample compression and shearing tests under the effect of simulating blasting vibration effect indoors, can conveniently simulate the influence of different blasting vibration response main frequencies and peak speeds on the rock sample, and is high in test efficiency and consistent with real conditions in results.
Drawings
FIG. 1 is a schematic diagram of an I-axis structure of a rock sample shearing box for simulating blasting vibration effect according to the invention.
FIG. 2 is a schematic view of the II-axis structure of the shear box of the present invention.
Fig. 3 is a schematic front sectional view of fig. 2 according to the present invention.
Fig. 4 is a schematic axial view of the filter pad of the shear box according to the present invention.
Fig. 5 is a schematic view of an axis measurement structure of the sensor fixing frame of the present invention.
In the figure: 1-loading cushion blocks in a normal direction; 2-hexagon socket head cap screw; 3, upper top plate; 4-upper shearing body; 5, a filtering cushion group; 6-screw thread pin; 7-lower bottom plate; 8-lower shear body; 9-a sensor mount; 10-displacement monitoring hole; 11-vibration signal monitoring hole; 12-rock sample; 51-filter pad A; 52-filter pad B; 61-screw pin hole; 91-bolt; 92, fixing a card; 93-a base; 94-bolt holes.
Detailed Description
The rock sample shearing box simulating the blasting vibration effect according to the present invention is further described with reference to the accompanying drawings and the specific embodiments, which are implemented on the premise of the technical solution of the present invention, but the protection scope of the present invention is not limited to the following embodiments.
Example 1: the invention provides a rock sample shearing box for simulating an explosion vibration effect, which is structurally shown in figures 1-5. The shearing box comprises an upper shearing box, a lower shearing box, a normal loading cushion block 1, a sensor fixing frame 9 and a filtering cushion block group 5; go up shear box and shear box central part down and be equipped with the cavity of placing rock specimen 12, rock specimen upper portion is equipped with normal direction loading cushion 1, and normal direction loading cushion 1 top contacts with the power loading structure of applying normal direction load, and normal direction loading cushion bottom is direct and rock specimen up end contact.
Referring to fig. 1 and 3, the upper shearing box is provided with an upper top plate 3 and an upper shearing body 4 which are connected by an inner hexagon bolt 2; the lower shearing box is provided with a lower bottom plate 7 and a lower shearing body 8 which are also connected by adopting an inner hexagon bolt;
referring to fig. 1 and 2, in the upper shearing body 4 perpendicular to the shearing direction, a rectangular window is arranged in the middle of one side surface of the upper shearing box and is used as a vibration signal monitoring hole 11; a rectangular window for placing the filtering cushion group 5 is arranged in the middle of the lower shearing body 8 of the lower shearing box on the other side face opposite to the vibration signal monitoring hole;
the filtering cushion group 5 is formed by connecting two filtering cushion blocks, namely a filtering cushion block A51 and a filtering cushion block B52, wherein the center parts of the two filtering cushion blocks are provided with threaded pin holes 61, and the filtering cushion group 5 is connected through the threaded pins 6 and the threaded pin holes 61. The filtering cushion block of the embodiment is made of two same copper filtering cushion block groups.
Referring to fig. 1 and 5, square grooves are arranged in the middle of two sides of the upper shearing box and the lower shearing box along the shearing direction to serve as displacement monitoring holes 10, and a sensor fixing frame 9 is arranged on the upper shearing body 4 on one side of each displacement monitoring hole for observing the rock sample shearing process. The sensor fixing frame consists of a base 93, a fixing clamp 92 and a bolt 91, the base is installed on the side part of the upper shearing body by inserting the bolt into a bolt hole 94, and the fixing clamp is also installed on the base by the bolt and the bolt hole; the sensor fixing frame is used for fixing the displacement sensor, the displacement sensor is clamped between the fixing clamp and the base, and the clamping degree of the displacement sensor is controlled through the adjusting bolt.
When the shear box is used for carrying out a simulation blasting vibration effect test indoors, the shear box is required to be tested together with a matched test system, and the test system comprises a displacement sensor, a sensor for monitoring vibration, a blasting vibration meter, a tangential actuator, a normal actuator, a dynamic impact device and a test station; a cuboid rock sample 12 with the same size as the inner cavity of the shear box is required to be prepared, the prepared rock sample is a cuboid rock sample with the size of 150mm multiplied by 75mm, the surface of the cuboid rock sample is polished to be smooth and then placed in the cavity of the lower shear box, then the cavity of the upper shear box is aligned with the rock sample, and a normal loading cushion block 1 is installed at the upper part of the rock sample; then, corresponding sensors are respectively installed in the displacement monitoring hole 10 and the vibration signal monitoring hole 11, and the test process is as follows:
selecting a blasting vibration signal to be simulated for analysis, determining a vibration response main frequency and a vibration peak speed which need to be generated under the action of an impact load of a rock sample, determining an excitation frequency for simulating vibration and the magnitude of a compression shear load, and making a test scheme;
placing a filtering cushion group 5 in a rectangular window on one side of a cutting box for installing the rock sample 12; as shown in fig. 4. Mounting a displacement sensor on a sensor fixing frame 9, simultaneously directly sticking a sensor for monitoring vibration on a rock sample at a vibration signal monitoring hole 11, and connecting the other end of the sensor for monitoring vibration with a blasting vibration meter; pushing the shearing box to a test station in a test system, and checking whether instruments, devices and sensors in the test system can work normally or not;
thirdly, starting the tangential actuator and the normal actuator to apply a preset pressing and shearing load to the rock sample through the shearing box, and performing dynamic intermittent impact on the filter cushion group 5 by using a dynamic impact device according to a test scheme in the pressing and shearing process;
fourthly, the rock sample is impacted through the filter cushion group to simulate the on-site blasting vibration effect, and whether the vibration signal monitored by the blasting vibration meter is similar to the main frequency of the blasting vibration signal to be simulated or not is observed and analyzed; if the difference is not similar, the material and the combination mode of the filter cushion group are adjusted according to the vibration signal value feedback, namely one or all of the filter cushions in the filter cushion group are adjusted to be replaced by filter cushions made of other materials, or the number of the filter cushions is adjusted, the filter cushion group is impacted again after the adjustment, the step is observed again, the step is repeated until the observed vibration signal is similar to the main frequency of the simulated blasting vibration signal, and the vibration signal can be observed to be similar to the main frequency of the simulated blasting vibration signal by generally adjusting for a plurality of times by means of signal value feedback, and the determined material and the combination mode of the filter cushion group are recorded;
fifthly, adjusting the impact energy of the dynamic impact device, observing whether the rock sample vibration peak speed monitored by the vibration meter is similar to the vibration peak speed of the blasting vibration signal to be simulated or not, repeating the step if the rock sample vibration peak speed monitored by the vibration meter is not similar to the vibration peak speed of the blasting vibration signal to be simulated, adjusting the impact energy value according to the vibration signal feedback until the rock sample vibration peak speed is similar to the vibration peak speed of the blasting vibration signal to be simulated, and recording the determined impact energy value;
sixthly, replacing the rock sample 12, performing a compression shear test simulating the blasting vibration effect according to the excitation frequency and the compression shear load determined by the test scheme, the material and the combination mode of the filter pad group determined by the step and the impact energy determined by the step, and observing and recording test data obtained by measuring a displacement sensor and a sensor for monitoring vibration until the test is completed;
and after the test is finished, pushing the shearing box away from the test station, opening the shearing box and taking out the rock sample, and cleaning the cavity in the shearing box and then installing the shearing box for the next use.
Example 2: the invention provides a rock sample shearing box for simulating blasting vibration effect, which has the structure basically the same as that of the rock sample shearing box used in the test process in the embodiment 1; different filtering cushion blocks are made of polyethylene and polyvinyl chloride respectively.
The shearing box is suitable for indoor tests for simulating the influence of blasting vibration on the mechanical properties of the rock sample, can conveniently simulate the influence of different blasting vibration response frequencies and peak speeds on the rock sample, and has high test efficiency and consistent results with real conditions.
Claims (4)
1. A rock sample shearing box for simulating blasting vibration effect is provided with an upper shearing box, a lower shearing box and a normal loading cushion block; the upper shearing box is formed by connecting an upper top plate and an upper shearing body by using an inner hexagon bolt; the lower shearing box is formed by connecting a lower shearing body and a lower bottom plate by using an inner hexagon bolt; the center parts of the upper shearing box and the lower shearing box are provided with cavities for placing rock samples, the normal loading cushion block is placed on the rock samples, the bottom of the normal loading cushion block is in contact with the upper end face of the rock sample, and the top of the normal loading cushion block is in contact with a power loading structure for applying normal load; the method is characterized in that:
the upper shearing box is arranged in an upper shearing body vertical to the shearing direction, and the middle of one side surface of the upper shearing box is provided with a rectangular window as a vibration signal monitoring hole; the middle part of the lower shearing body of the lower shearing box on the other side surface opposite to the vibration signal monitoring hole is provided with a rectangular window for placing the filtering cushion group;
the middle parts of the two sides of the upper shearing box and the lower shearing box along the shearing direction are provided with square grooves as displacement monitoring holes and observation ports for observing the rock sample shearing process; a sensor fixing frame is arranged on the upper shearing body on one side of each displacement monitoring hole;
the sensor fixing frame is composed of a base, a fixing clamp and a bolt, the base is installed on the side portion of the upper shearing body through the bolt and a bolt hole, and the fixing clamp is fixed on the base through the bolt.
2. The rock sample shearing box for simulating the blasting vibration effect as claimed in claim 1, wherein: the filtering cushion group consists of two or more filtering cushion blocks, pin threaded holes are formed in the center of each filtering cushion block, and the filtering cushion block is connected with the pin threaded holes through threaded pins to form the filtering cushion group.
3. The rock sample shearing box for simulating the blasting vibration effect as claimed in claim 1, wherein: the combination mode of the filtering cushion block group is the combination of filtering cushion blocks made of the same material or different materials.
4. The rock sample shearing box for simulating the blasting vibration effect is characterized in that: the sensor fixing frame is used for installing a displacement sensor, the sensor is clamped between the fixing clamp and the base, and the clamping degree of the sensor is controlled through the adjusting bolt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110440661.6A CN115235922A (en) | 2021-04-23 | 2021-04-23 | Rock sample shearing box simulating blasting vibration effect |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110440661.6A CN115235922A (en) | 2021-04-23 | 2021-04-23 | Rock sample shearing box simulating blasting vibration effect |
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| CN115235922A true CN115235922A (en) | 2022-10-25 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113218790A (en) * | 2021-04-23 | 2021-08-06 | 武汉科技大学 | Rock sample compression shear test method for simulating blasting vibration effect |
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2021
- 2021-04-23 CN CN202110440661.6A patent/CN115235922A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113218790A (en) * | 2021-04-23 | 2021-08-06 | 武汉科技大学 | Rock sample compression shear test method for simulating blasting vibration effect |
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