CN209215095U - A Rock Test Block Fixing Device for Point Load Test - Google Patents

Abstract

The utility model provides a rock test block fixing device for a point load test, which includes a bearing box for placing the rock test block. The load box includes an upper plate, a lower plate and a side plate. The main body of the box is connected, and the elastic force of the elastic connector is greater than the sum of the gravity of the rock test block and the lower plate, so that after the rock test block is placed in the carrying box, the rock test block can move up with the lower plate under the elastic force of the elastic connector. Finally, it will be offset against the upper conical indenter, so that the rock test block is fixed. The utility model makes it no longer necessary to manually grasp the rock test block by hand during the point load test, eliminates potential safety hazards, improves the convenience of operation, and saves manpower. The upper and side plates of the carrying box play a splash-proof role for the rock test block and enhance the safety of the test. At the same time, it also prevents the possibility of avalanche and long-distance movement of small blocks formed after the rock test block is cracked. It is convenient for splicing and restoration of small blocks in the later stage.

Description

A Rock Test Block Fixing Device for Point Load Test

technical field

The utility model relates to point load test equipment, in particular to a rock test block fixing device for point load test.

Background technique

In order to obtain the uniaxial compressive strength of the rock, it is generally necessary to process the rock into a standard rock sample, and use a press to perform a compression test on the rock sample indoors. The process of processing standard rock samples will inevitably cause secondary damage to the original rock, for example: destroying the internal microstructure of the rock itself, thus affecting the accuracy of the test results to a certain extent. The point load test can test the rock test block without processing the original rock, which has certain advantages.

Point load test is widely used in various engineering fields, such as mining engineering, civil engineering and geological engineering. Compared with the indoor rock mechanics test, the point load test has the characteristics of portability, rapidity and low cost. During the point load test, a point load tester is used to complete the strength determination of the rock test block, which is mainly composed of a base, a hand hydraulic pump, a conical indenter, and a fixed rod. At the work site, select the rock test block to be measured, place it between the upper and lower pressurized conical heads of the point load tester, and shake the hydraulic jack pressure lever until the rock test block is damaged, then stop the pressurization (that is, stop the operation) pressure rod).

There are following defects in existing point load tester:

1. The rock test block is positioned manually before the test, and the rock sample is grasped by hand and sent to a position close to the bottom of the upper conical indenter. Since the upper conical indenter cannot maintain the stability of the test block, the lower conical indenter is required. When the indenter is pressed against the rock test block, the test block can only be released after the test block does not move. On the one hand, the cone head is easy to press the hand, which has a large safety hazard; on the other hand, before the lower conical indenter is pressed to the rock test block , One hand fixes the rock test block and cannot be loosened, while the other hand needs to operate the hydraulic jack pressure rod to raise the lower conical head, which is very inconvenient.

2. After fixing the rock test block, continue to shake the hydraulic jack until the test block is crushed, then stop pressurizing. During this process, the rock test block is prone to cracking due to the pressure. The pressurized rock test block has energy, and the debris of the rock test block will splash around. On the one hand, it is very easy to hurt the test operator; After the rock test block was splashed around, the position of each split block changed, and it was difficult to find the original position of the split block on the whole test block before the test, especially for rocks with high brittleness. Due to the large number of small blocks produced after the test, it is difficult to splice and restore the broken small blocks after the test, and it is impossible to compare and analyze the shape and crack damage of the rock test block after the crack with the overall test block before the test. affect the conduct of research work.

Patent CN201320808075.3 discloses a point load test device with radial clamping, which includes a hydraulic pressure testing machine for loading, a specimen clamping device used in conjunction with the pressure testing machine, and upper and lower loading Cone; the structure of the specimen clamping device is: a height-adjustable pad column is provided on the central axis of the hydraulic cylinder head of the hydraulic pressure testing machine, and a backing plate is provided on the pad column; Adjustable left and right longitudinal rods; the symmetrical positions on the left and right longitudinal rods are respectively equipped with transverse rods that can be pushed and pulled horizontally, and the inner ends of the two transverse rods are respectively equipped with arc-shaped elastic clamping pads, requiring two The arc of the clamping pad corresponds. This patent mainly designs a radial clamping device, which achieves the purpose of safety testing to a certain extent, but the patent CN201320808075.3 still has the following shortcomings:

1. The structure is complex and the operation is cumbersome. Using the clamping device disclosed in the patent CN201320808075.3 requires at least four connecting rods at the front, rear, left, and right to achieve the purpose of fixing the rock test block, and the structure is relatively complicated; and it may be necessary to adjust the backing plate connecting rod four times in order to clamp a rock test block, and Left and right must be adjusted, if the adjustment position is not appropriate, it will also affect the test results. Generally, hundreds of rock test block tests are carried out in point load tests, and the connecting rod of the backing plate must be adjusted for each test, which virtually increases the test time.

2. The security is not high. Patent CN201320808075.3 only sets the clamping device on the left and right sides of the rock test block, but does not set the clamping device on the front and rear sides of the rock test block. Splashing and avalanche direction have great uncertainty, so after the rock test block is broken, the device cannot completely prevent the broken rock from falling from the front and rear sides and hurt people, especially for brittle rock test blocks.

3. Affect the test results. The clamping pad in the clamping device disclosed in patent CN201320808075.3 clamps the rock test block from the left and right directions, but it is difficult to accurately evaluate and control the clamping force of the clamping pad on the rock test block. The clamping force of the rock test block virtually exerts a confining pressure on the rock test block. At this time, the mechanical parameter measured by the experimental device is not the uniaxial compressive strength, but the strength under a certain confining pressure.

Therefore, there is still a need for a solution in the prior art to solve the above technical problems.

Utility model content

The purpose of the utility model is to provide a rock test block fixing device for point load test, so as to solve the problems raised in the background technology.

A rock test block fixing device for a point load test, comprising a carrying box 1 for placing a rock test block 4 and a connecting part 3 for supporting and connecting the carrying box, one end of the connecting part is connected to the carrying box, The other end is connected with the support frame of the point load tester. The carrying box includes an upper plate 11, a lower plate 12 and a side plate 13. The upper plate and the side plates constitute the main body of the carrying box, and the upper plate is located near the upper conical indenter. 28 bottom position, the main body of the carrying box is connected with the connecting part 3 as a fixed part, and the lower plate is connected with the main body of the carrying box through an elastic connector 14 as a movable part. For the upper conical indenter 28 to extend downwards into the through hole 15 inside the carrying box, the lower plate is provided with a lower conical indenter 27 at the position corresponding to the lower conical indenter to extend upwards into the inside of the carrying box Through hole 2 16, the elastic direction of the elastic connector is set along the up and down direction, the elastic force of the elastic connector is greater than the sum of the gravity of the rock test block and the lower plate, so that the rock test block is placed on the lower plate through the At the position of hole 2 and aligned with the upper conical indenter, the rock test block can move up with the lower plate under the elastic force of the elastic connector until it finally resists the upper conical indenter, so that the rock test block is fixed. The elastic force of the elastic connector does not need to be too large, it only needs to be able to hold up the rock test block, which can fix the rock test block without affecting the test results.

When doing a point load test, the position of the upper plate is set to be higher than the bottom of the upper conical indenter, and the higher height is greater than or equal to the depth of depression at the contact point between the rock test block and the upper conical indenter, that is, the upper cone The bottom of the shaped indenter extends into the carrying box through the through hole, so that the rock test block with a concave surface is always located under the upper plate during the test, which has a good effect of preventing collapse and splashing.

The carrying box is a rectangular box, and the elastic connectors are symmetrically distributed on the four corners of the carrying box, and at least one is provided at each corner to provide balanced support for the rock test block.

The elastic connector adopts a spring, the upper end of the spring is connected with the upper plate of the main body of the carrying box, and the lower end of the spring is connected with the lower plate.

The top edge of the side plate is fixed together with the edge of the upper plate, and the height h of the side plate is smaller than the height dimension H of the rock test block along the axial direction of the upper and lower conical indenters, so as to prevent the rock test block from contacting the upper conical indenter. The interference between the bottom edge of the side plate and the lower plate affects the positioning of the rock test block, and at the same time prevents the small blocks formed after the rock test block is cracked from completely dispersing, which is helpful for the later splicing and restoration work.

The height h of the side plate is greater than or equal to 1/2 of the height dimension H of the rock test block along the axial direction of the upper and lower conical indenters, so that the side plate forms a sufficient splash-proof shielding area around the rock test block.

The through hole 1 and the through hole 2 are circular holes, the centers of the through hole 1 and the through hole 2 are located on the axis line of the upper and lower conical indenters, and the diameter of the through hole 1 is larger than the diameter of the upper conical indenter by 1~ 3mm, the diameter of through hole 2 is larger than the diameter of the lower conical indenter by 1~3mm, in order to prevent the edges of through hole 1 and through hole 2 from interfering with the side walls of the upper and lower conical indenters, and the size of through hole 1 and through hole 2 If it is set to a suitable size, the upper plate can form a sufficient splash-proof shielding area above the rock test block, and the lower plate can provide a sufficiently stable supporting area for the rock test block. The hole diameters of through hole 1 and through hole 2 should not be too small or too large. If it is too small, it will interfere with the upper and lower conical indenters. If it is too large, it will affect the placement and fixing of the rock test block. The size of the block is generally larger than the diameter of the upper and lower conical indenters. Setting the size of through hole 1 and through hole 2 to be 1 to 3 mm larger than the size of the upper and lower conical indenters basically ensures that the size of the rock test block is larger than that of the through hole. Dimensions of hole 1 and through hole 2.

The connection between the connecting part and the support frame of the point load tester is a detachable connection, such as a bolt connection or a buckle connection, so that the installation position of the connecting part and the bearing box can be adjusted as required.

The connecting parts are connecting rods, and the connecting rods are two symmetrically arranged on both sides of the carrying box. The connecting rods are preferably Y-shaped connecting rods, and each connecting rod has two connection points with the main body of the carrying box. connection, while the other connection point is connected to the support frame of the point load tester. Setting the connecting rods into a Y-shaped structure can increase the stability of the carrying box and prevent the carrying box from swinging up and down or even deflecting.

The side plate is a non-porous plate, the upper plate is of a non-porous structure except through hole 1, and the lower plate is a mesh plate with a mesh 121, and the mesh is used to crack the rock test block The formed debris leaks out in time so as not to affect the test of the next test block. Since the point load test generally requires hundreds of tests, the debris produced by each rock test block can be discharged in time, which will greatly reduce the overall work intensity and improve work efficiency. Or the lower plate is a wire mesh structure, and the wire diameter in the wire mesh structure is 0.5 to 5 mm, preferably 1 to 3 mm, and the size of the holes in the wire mesh structure is a unidirectional dimension (such as length, width or diameter in a single direction). size) is 3 to 30 mm, preferably 5 to 20 mm.

The connecting parts, the upper plate, the lower plate and the side plates are made of metal materials, such as stainless steel, alloy, carbon steel or iron.

The utility model also provides a point load tester, which includes the rock test block fixing device.

The utility model at least has the following beneficial effects:

The utility model arranges elastic connectors between the upper plate and the lower plate of the carrying box, and sets the lower plate into a movable structure that can expand and contract along the thickness. When the rock test block needs to be placed, the lower plate can be placed. In, the rock test block is placed at the second position of the through hole, the lower plate can carry the rock test block up to offset the upper conical indenter, during the test, it is no longer necessary to manually grasp the rock test block by hand, eliminating The safety hazard is avoided, and the structure of the whole device is simplified, and the operation is convenient. The operator can use one hand to press the jack or do other work. During the rising process of the lower conical indenter, it is no longer necessary to keep the position of the rock test block fixed. To keep the body in a certain fixed posture, the operator no longer has to stare at whether the lower conical indenter touches the rock test block, but can instead observe the intensity value displayed by the pressure sensor through the display, making it necessary for two people to cooperate in the past. The completed point load test can be completed by one person, which protects the safety of the test personnel, improves the convenience of operation and saves manpower.

The utility model plays an anti-splash effect on the rock test block through the upper plate and the side plate of the carrying box, enhances the safety of the test, and at the same time prevents the collapse and long-distance movement of the small blocks formed after the rock test block is cracked. Possibility, facilitate the splicing and restoration of small blocks in the later stage, ensure the integrity of small blocks after splicing to the greatest extent, and compare and analyze with the whole test block before the test.

In addition to the purposes, features and advantages described above, the present invention has other purposes, features and advantages. Below with reference to figure, the utility model is described in further detail.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide a further understanding of the utility model, and the schematic embodiments of the utility model and their descriptions are used to explain the utility model, and do not constitute an improper limitation of the utility model. In the attached picture:

Fig. 1 is the installation effect drawing (main view direction) of the rock test block fixing device of the preferred embodiment of the present invention;

Fig. 2 is the three-dimensional structural diagram of the rock test block fixing device of the preferred embodiment of the present invention (the upper plate is shown as a transparent structure in Fig. 2);

In the figure: 1-carrying box, 11-upper plate, 12-lower plate, 121-mesh, 13-side plate, 14-elastic connector (spring), 15-through hole one, 16-through hole two, 17 - screws;

2-point load tester, 20-base, 21-upper horizontal support, 22-lower horizontal support, 23-left vertical support rod, 24-right vertical support rod, 25-jack, 26-locating nut, 27- Lower conical indenter, 28-upper conical indenter, 29-monitor;

3-connecting parts, 4-rock test block.

Detailed ways

The embodiments of the utility model will be described in detail below in conjunction with the accompanying drawings, but the utility model can be implemented in various ways defined and covered by the claims.

A kind of rock test block fixing device for point load test, this rock test block fixing device is arranged on the hydraulic type point load tester 2, referring to Fig. 1, described point load tester comprises base 20 and is arranged on the base The jack 25 is fixedly connected with a support frame on the cylinder body of the large oil cylinder of the jack. It is arranged parallel to the support and the lower ends of the two are respectively fixedly connected with the two ends of the lower transverse bracket, and the upper end is set in the preset guide hole of the upper transverse bracket, and is locked and positioned by the positioning nut 26. After the positioning nut 26 is loosened, the upper The horizontal support can slide up and down along the left vertical support rod and the right vertical support rod, so that the vertical distance between the upper horizontal support and the lower horizontal support can be adjusted, and the middle part of the lower horizontal support is fixedly connected with the large oil cylinder of the jack , the fixed connection between the lower transverse support and the cylinder body of the large cylinder of the jack is provided with a via hole (not shown in Fig. 1) for the piston rod of the large cylinder of the jack to protrude upwards; , the upper conical indenter 28 is fixed on the bottom of the upper horizontal support, the upper conical indenter and the lower conical indenter are vertically arranged and maintain a coaxial positional relationship; the base and the support frame are used as the support system of the point load tester, and the jack 1. The upper conical indenter and the lower conical indenter are used as the loading system of the point load tester. In this embodiment, a pressure sensor (not shown in Fig. 1) is embedded in the upper conical indenter. The display 29 that is used to display the real-time strength value is permanently connected, and the pressure sensor and the display are used as the force measuring system of the point load tester. The rock test block fixing device proposed by the utility model is arranged on the left vertical support bar 23 and the right vertical Between the support rods 24.

Referring to Fig. 2, the rock test block fixing device includes a carrying box 1 for placing a rock test block 4 and a connecting part 3 for supporting and connecting the carrying box.

One end of the connecting part is connected with the side plate 13 of the carrying box, and the other end is connected with the support frame of the point load tester. Referring to Fig. 1 and Fig. 2, the connecting part 3 of the rock test block fixing device is two symmetrically distributed Root, the width direction of the connecting part is set along the axial direction of the upper and lower conical indenters, the left end of the left connecting part is detachably connected to the left vertical support rod through a screw 17, and the two connecting points on the right end are connected to the left side of the carrying box The plates are welded and fixed together; the right end of the connecting part on the right is detachably connected to the right vertical support bar through screws 17, and the two connection points at the left end are welded and fixed with the right plate of the bearing box. According to the size of the rock test block, The height position of the adjustable connecting part on the left and right vertical support rods makes the rock test piece 4 contact the upper conical indenter 28.

The carrying box is a rectangular box, and the carrying box includes an upper plate 11, a lower plate 12 and a side plate 13. The side plate can be a bent whole plate, or can be spliced by four straight plates. The edge of the upper plate and the side plate The four top edges of the plate are welded to form the main body of the carrying box. The upper plate is located near the bottom of the upper conical indenter 28. The main body of the carrying box is connected to the connecting part 3 as a fixed part, and the lower plate is connected to the main body of the carrying box through the elastic connector 14 as a movable part. connected, the upper plate is provided with a through hole 15 for the upper conical indenter 28 to extend downward into the inside of the carrying box at the position corresponding to the upper conical indenter, and the corresponding lower conical indenter on the said lower plate The position of the head is provided with a through hole 16 for the lower conical indenter 27 to extend upwards into the inside of the carrying box. The elastic direction of the elastic connector is set along the up and down direction, and the elastic force of the elastic connector is greater than that of the rock test block and the The sum of the gravity of the lower plate makes the rock test block be placed on the second through hole on the lower plate and aligned with the upper conical indenter, and the rock test block can move upward with the lower plate under the elastic force of the elastic connector Move until it is finally against the upper conical indenter, thereby completing the positioning of the rock test block.

Due to the existence of elastic connectors, the support of the lower plate to the rock test block is a dynamic support that moves upward automatically after the rock test block breaks, which can effectively prevent the rock test block from falling like a free fall, thereby The original state of the small blocks formed after the rock test blocks were broken is guaranteed to the greatest extent, which is helpful for the later splicing, restoration and comparative analysis. In the utility model, while the second through hole is used as a channel for the lower conical indenter to pass through, it also has an auxiliary positioning effect on the rock test block, and the lower plate is pulled downward, and the rock test block is placed in the second through hole. That is to say, it can ensure that the rock test block is located under the through hole 1 and the upper conical indenter, and only need to fine-tune the position of the rock test block or basically do not need to adjust the position of the rock test block, saving time and effort, and improving test efficiency.

The position of the upper plate is set to be 3-8 mm higher than the bottom of the upper conical indenter, that is, the bottom of the upper conical indenter extends into the carrying box by about 3-8 mm, preferably 5 mm, through the through hole. It is greater than the depression depth of the contact between the rock test block and the upper conical indenter, so that the rock test block with a concave surface is always located under the upper plate during the test, which has a good anti-collapse effect and ensures the safety of the experimenters.

Referring to Fig. 2, in this embodiment, the elastic connectors are distributed symmetrically at the four corners of the carrying box, and each corner is provided with a spring with an elastic coefficient of 100-300N/m, preferably 200N/m m, together provide balanced support for the rock test block.

The elastic connector adopts a spring, the upper end of the spring is connected with the upper plate of the main body of the carrying box, and the lower end of the spring is connected with the lower plate.

The top edge of the side plate and the edge of the upper plate are welded and fixed together, and the height h of the side plate is less than the height dimension H of the rock test block along the axial direction of the upper and lower conical indenters, so as to prevent the gap between the rock test block and the upper conical indenter. Before offsetting, the bottom edge of the side plate interferes with the lower plate to affect the positioning of the rock test block, and at the same time prevents the small blocks formed after the rock test block is cracked from completely dispersing, which is helpful for the later splicing and restoration work.

The height h of the side plate is equal to 1/2 of the height dimension H of the rock test block along the axial direction of the upper and lower conical indenters, so that the side plate forms a sufficient splash-proof shielding area around the rock test block.

The first through hole and the second through hole are round holes, and the centers of the first through hole and the second through hole are located on the axis line of the upper and lower conical indenters, and the diameter of the first through hole is greater than the diameter of the upper conical indenter by 2 mm. The diameter of through hole 2 is larger than the diameter of the lower conical indenter by 2 mm, so as to prevent the edges of through hole 1 and through hole 2 from interfering with the side walls of the upper and lower conical indenters, and to make the upper plate form sufficient splash protection above the rock test block Cover the area so that the lower plate provides a sufficiently stable support area for the rock test block.

In this embodiment, the side plate is a non-porous plate, the upper plate is of a non-porous structure except through hole 1, and the lower plate adopts an iron wire mesh with a mesh 121, and the mesh is used for In order to make the debris formed by cracking the rock test block leak out in time, so as not to affect the test of the next test block. Since the point load test generally requires hundreds of tests, the debris produced by each rock test block can be discharged in time, which will greatly reduce the overall work intensity and improve work efficiency. Of course, if the lower plate is a plate without mesh, debris generated by fracturing the rock test block can be removed in time after each point load test. In this embodiment, the connecting parts, the upper plate, the lower plate and the side plates are all iron plates.

In this embodiment, the size of the carrying box is 10 cm long x 10 cm wide x 2 cm high, the mesh size of the lower plate is 1 cm x 1 cm, the diameter of the iron wire of the lower plate is 2 mm, and the size of the lower plate is the same as that of the upper plate, both of which are 10 cm x 10 cm long. The width is 10cm, and the dimensions of the four side panels are all 10cm in length and 2cm in width. The four corners of the barbed wire mesh on the lower plate are connected with the four corners of the upper plate by four small springs 14. The lower plate can float up and down, which is convenient for putting in the rock test block 4 and can also fix the rock test block. The rock test block is not placed in the carrying box. When block, the lower plate is in contact with the bottom edge of the side plate under the pull of the spring.

Use the rock test block fixing device of the present utility model to carry out the process of point load test roughly as follows:

Install the rock test block fixing device on the point load tester, loosen the screw 17 to adjust the position of the rock test block fixing device, and then tighten the screw 17 to fix the load after the bottom of the upper conical indenter extends into the carrying box for about 5mm box. Turn on the force measurement system and zero the raw data.

Pull the lower plate downwards, put the rock test block 4 into the second position of the through hole of the bearing box, and rely on the pulling force of the spring 14 to pull the lower plate to fix the rock test block.

Open the jack oil valve, shake the jack pressure rod to load, stop loading after the rock test block is broken, read the point load strength of the rock test block through the display 29, retract the lower conical pressure head, pull the lower plate downward, and take out The small blocks obtained after crushing are placed in the designated location for comparative research in the later stage, and the point load test of the next rock test block is carried out.

The above descriptions are only preferred embodiments of the utility model, and are not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (10)

1. a kind of fixed device of rock test block for Point Load Tests, which is characterized in that including for placing rock test block (4) Carrier box (1) and be used to support the connecting component (3) of connection Carrier box, described connecting component one end and the Carrier box connect It connects, the support frame connection of the other end and Point Load Strength Instrument, the Carrier box includes upper plate (11), lower plate (12) and side plate (13), the upper plate and side plate constitute carrying box main body, and carrying box main body is connect with connecting component, and lower plate passes through flexible connector (14) it connect with carrying box main body, is provided on the upper plate in the position of the upper conical pressure head of correspondence for upper conical pressure head (28) The through-hole one (15) inside Carrier box is extended downwardly into, is provided in the lower plate in the position of corresponding inferior pyramidal pressure head for lower cone Shape pressure head (27) extends upwardly into the through-hole two (16) inside Carrier box, and the elastic force of the flexible connector is greater than rock test block under The sum of gravity of plate, so that at the position for the through-hole two rock test block being placed in lower plate and after the upper conical pressure head of alignment, Rock test block can the elastic force of flexible connector effect under with lower plate be moved upward to it is final offset with upper conical pressure head, to make Rock test block is fixed.

2. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described Upper plate is located at close to the position of upper conical pressure head (28) bottom, and when doing Point Load Tests, the position of the upper plate is set as high In upper conical pressure head bottom.

3. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described Flexible connector uses spring, and spring upper end is connect with the upper plate of Carrier box main part, and lower spring end is connect with lower plate.

4. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described The elastic force direction of flexible connector is arranged along the vertical direction, and the Carrier box is rectangular box, and flexible connector, which is symmetrically distributed in, to be held Four angles of box are carried, each angle is at least arranged one.

5. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described The top margin of side plate is fixed together with upper board edge, and the height h of side plate is less than rock test block vertically conical indenter axial direction Height dimension H, the height h of the side plate is greater than or equal to the height dimension of rock test block vertically conical indenter axial direction The 1/2 of H.

6. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described Through-hole one and through-hole two are circular hole, and through-hole one and the center of circle of through-hole two are respectively positioned on the axial line of upper and lower conical indenter, through-hole One is greater than 1~3mm of diameter of upper and lower conical indenter with the aperture of through-hole two.

7. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described Connecting component is connecting rod, and the connecting rod is Y shape connecting rod, is held there are two tie point with described in every Y shape connecting rod Box main body connection is carried, and another tie point is connect with the support frame of the Point Load Strength Instrument.

8. a kind of fixed device of rock test block for Point Load Tests according to claim 1, which is characterized in that described Connecting component is removably to connect with the connection of Point Load Strength Instrument support frame, is such as bolted or snaps connection.

9. a kind of fixed device of rock test block for Point Load Tests described according to claim 1~any one of 8, It is characterized in that, the lower plate uses the web plate with mesh (121)；Or the lower plate is screen net structure.

10. a kind of fixed device of rock test block for Point Load Tests according to claim 9, which is characterized in that institute Stating the wire diameter in screen net structure is 0.5~5mm, and the hole size in screen net structure is unidirectional 3~30mm of size.