CN111208003A - Testing device for stress distribution form of block contact surface of masonry beam structure - Google Patents

Abstract

The invention belongs to the technical field of mining engineering roof control; the invention provides a testing device for the stress distribution form of the contact surface of a masonry beam structure block, which comprises a press machine and a testing system, wherein the testing system is positioned on the press machine, two parallel vertical fixing plates are vertically fixed on two transverse fixing plates, a rotary shaft at the inner side of the vertical fixing plates adjusts the height difference of two rock test pieces through a clamping ring, a thin film stress tester is arranged on the contact surface of the rock test piece, and a displacement sensor is used for detecting the displacement of the rock test piece in the rotation process, so that the accuracy and the reasonability of the working resistance of a coal face support are improved, high safety and high applicability.

Description

Testing device for stress distribution pattern of masonry beam structure block contact surface

technical field

The invention relates to the field of roof control of mining engineering, in particular to a testing device for stress distribution patterns of contact surfaces of masonry beam structural blocks.

Background technique

The mining of underground coal resources causes the breaking movement of the overlying strata, which causes the mine pressure to appear on the coal mining face. As the main carrier of stope roof control, working face hydraulic support, scientific determination and reasonable determination of its working resistance is the basis for ensuring safe and efficient mining in mines. With the advancement of the coal mining face, the roof strata of the stope are broken, and the key blocks are hinged to each other and rotate in the form of a masonry beam structure, and finally a stable masonry beam structure is formed. At the same time, the dynamic rotary motion of the key blocks of the masonry beam structure forms the roof compression process of the coal mining face. Therefore, it is of great significance to scientifically control the stope roof to grasp the dynamic motion law of the key blocks to determine the reasonable working resistance of the support. However, at present, there are few studies on the distribution pattern of the contact surface extrusion stress and its variation law during the rotary motion of the key blocks of the masonry beam structure, and there is also a lack of corresponding test devices, so it is still impossible to accurately characterize the key blocks of the masonry beam structure. The force state and its change law during the slewing motion cause errors in the stability calculation of the hinged blocks of the relevant masonry beam structures, and also reduce the accuracy of the theory applied to the on-site roof control practice.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the purpose of the present invention is to provide a testing device for the stress distribution pattern of the contact surface of the masonry beam structure block, and the invention improves the accuracy and efficiency of the roof control of the stope.

For achieving the above object, the present invention provides the following technical solutions:

A testing device for the stress distribution form of the contact surface of a masonry beam structure block, including a press and a test system, the test system is located under the loading beam of the press, and includes a base and a fixing frame for a rock specimen, and the base is provided with a number of base limits The hole, the base limit hole is divided into two groups of parallel distribution; the fixing frame is arranged on the upper surface of the base, including two vertical fixing plates and two horizontal fixing plates, the two vertical fixing plates are placed vertically and parallel, and the two vertical fixing plates The horizontal fixing plates are respectively vertically fixed to the center of the two horizontal fixing plates, the two horizontal fixing plates are fixed on the upper surface of the base by positioning bolts, and the edges of the two horizontal fixing plates are parallel, and the horizontal fixing plates are provided with several fixing plate limit holes. The distance between the limit holes of the fixing plate is the same as the distance between the limit holes of the base, and the distance D between the two horizontal fixing plates is adjusted by the positioning bolts passing through the limit holes of the fixing plate and the limit holes of the base at different positions; The inner side is provided with a number of equally spaced snap rings along the vertical direction. The snap rings are divided into two columns, which are respectively located at the vertical edges of the vertical fixing plates. The two ends of the rotating shaft pass through the snap rings at the same level at the two ends of the vertical fixing plate respectively. The height of the rotating shaft is adjusted by inserting the snap rings of different heights into the vertical fixing plate. A specimen holder is located between the snap rings at both ends of the rotary shaft; the first rock specimen and the second rock specimen are respectively placed on the specimen holders of the two rotary shafts, and between the two rock specimens A thin film stress tester is set on the contact surface between the two; the bottom of the first rock specimen is connected to a displacement sensor for testing the sinking displacement of the first rock specimen, and the rock block loading plate at the bottom of the loading beam is close to the top of the first rock specimen, and the pressure The machine pressurizes the first rock specimen through the rock block loading disc.

Further, the base limiting hole is a through hole.

Further, the snap ring is an omega-type with both ends horizontal and the middle convex, and both ends are fixed to the inner side of the vertical fixing plate by welding or bolts.

Further, the film stress tester and the displacement sensor are respectively connected with the computer, and the measured data are transmitted to the computer.

Further, the thin film stress tester is located on the contact surface of the second rock specimen or the first rock specimen.

Further, the specimen support includes an angle steel and a hinge, the hinge is welded on the outer side of the angle steel, and the rotating shaft of the hinge is welded on the rotating shaft.

To sum up, the invention has the following beneficial effects:

The invention can accurately grasp the stress distribution form and evolution law of the key block contact surface of the roof masonry beam structure of the working face, improve the accuracy and rationality of the working resistance of the support of the coal mining face, and has high safety and strong applicability.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Fig. 2 is the structural representation of the test piece support of the present invention;

FIG. 3 is a schematic diagram of the structure of the snap ring.

In the picture: 1- The first rock specimen, 2- Vertical fixing plate, 3- Position ring, 4- Rotary shaft, 5- Limit hole of fixing plate, 6- Horizontal fixing plate, 7- Base, 8- Base Limit hole, 9-positioning bolt, 10-hinge, 11-angle steel, 12-membrane stress tester, 13-displacement sensor, 14-computer, 15-second rock specimen.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, a test device for the stress distribution of the contact surface of the masonry beam structure block, including a press and a test system, the test system is located under the loading beam of the press, and includes a base 7 and a fixing frame for rock specimens The base 7 is provided with a plurality of base limit holes 8, the base limit holes 8 are divided into two groups and distributed in parallel, and the base limit holes 8 are through holes.

The fixing frame is arranged on the upper surface of the base 7, including two vertical fixing plates 2 and two horizontal fixing plates 6, the two vertical fixing plates 2 are placed vertically and parallel, and the two vertical fixing plates 2 are respectively vertically fixed to the two vertical fixing plates 2. In the center of the two lateral fixing plates 6, the two lateral fixing plates 6 are fixed on the upper surface of the base 7 by positioning bolts 9, and the edges of the two lateral fixing plates 6 are parallel. The spacing of the limit holes 5 is the same as the spacing of the base limit holes 8, and the spacing D of the two lateral fixing plates 6 passes through the fixed plate limit holes 5 and the lateral fixing plates 6 at different positions on the base 7 through the positioning bolts 9. The limit holes 8 of the base at different positions are adjusted, and the distance D is adjusted according to the size of the rock specimen, so that the two rock specimens are located between the two vertical fixing plates and are in contact.

The inner two ends of the vertical fixing plate 2 are arranged along the vertical direction with a plurality of snap rings 3 distributed at equal intervals. As shown in FIG. 3 , the snap rings 3 are Ω-shaped with horizontal ends and a raised middle, and both ends are welded by welding. Or the bolts are fixed on the inner side of the vertical fixing plate 2, and the snap ring 3 is divided into two rows, which are respectively located at the vertical edges of the vertical fixing plate 2, and the inner sides of the two vertical fixing plates 2 are horizontally provided with the rotating shaft 4, and the back Both ends of the rotating shaft 4 respectively pass through the snap rings 3 at the same horizontal height at both ends of the vertical fixing plate 2, and the height of the rotating shaft 4 is adjusted by inserting the snap rings 3 of different heights into the vertical fixing plate 2, and Two specimen brackets are welded on each rotary shaft 4, and the specimen brackets are located between the snap rings 3 at both ends of the rotary shaft 4; as shown in Figure 2, the specimen brackets include angle steel 11 and hinge 10, and the hinge 10 is welded On the outside of the angle steel 11, the hinge 10 is welded on the rotating shaft 4 at the rotating shaft.

The first rock specimen 1 and the second rock specimen 15 are respectively placed on the specimen supports of the two rotating shafts 4, and a film stress tester 12 is set on the contact surface between the two rock specimens, and the film stress tester 12 Located on the contact surface of the second rock specimen 15 or the first rock specimen 1, it is used to test the stress distribution of the contact surface of different rock specimens during the rotational motion; the bottom of the first rock specimen 1 is connected to test the displacement of the rock specimen The displacement sensor 13, the rock block loading plate at the bottom of the loading beam is close to the top of the first rock sample 1, and the press pressurizes the first rock sample 1 through the rock block loading plate; the film stress tester 12 and The displacement sensors 13 are respectively connected with the computer 14, and the measured data is transmitted to the computer 14. The film stress tester 12 uses Tekscan I-Scan, and the displacement sensor 13 is model ZHLS125-1M; Then, the rotary shaft 4, the specimen support and the rock specimen located on the same side of the film stress tester 12 can be regarded as a whole, and the rotary shaft 4 on the same side can be rotated as the axis.

The assembly process and adjustment of the present invention are as follows: the vertical fixing plate 2 is vertically placed in the center of the horizontal fixing plate 6, and the two vertical fixing plates 2 are placed in parallel. The materials of the horizontal fixing plate 6 and the vertical fixing plate 2 are both Steel plates, the two are welded and fixed, and the lateral fixing plate 6 is fixed on the base 7 using positioning bolts 9, and the distance D between the two lateral fixing plates 6 is adjusted through the different limit holes on the lateral fixing plate 6 and the base 7; The inner ends of the two vertical fixing plates 2 are equally spaced by welding the snap rings 3, the rotary shaft 4 is made of high-strength steel bars, the two ends of the rotary shaft 4 pass through the snap rings 3, the rotary shaft 4 is kept in a horizontal state, and the The height is adjusted by the snap ring 3, and the height difference of the two rotary shafts can be used to simulate the influence of the mining height of the working face on the stress distribution of the contact surface during the rotation of the key blocks of the masonry beam structure of the roof rock layer; the hinge 10 is welded on the On the outside of the angle steel 11, the angle between the two sides of the angle steel 11 is 90°, and the two are integrally welded on the rotary shaft 4 as the specimen support. The two rock specimens are rotated around the axis of rotation 4 .

The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims (6)

1. The utility model provides a testing arrangement of masonry beam structure block contact surface stress distribution form, includes press and test system, its characterized in that: the testing system is positioned below a loading cross beam of the press machine and comprises a base (7) and a rock test piece fixing frame, wherein the base (7) is provided with a plurality of base limiting holes (8), and the base limiting holes (8) are distributed in two groups in parallel;

the fixing frame is arranged on the upper surface of the base (7) and comprises two vertical fixing plates (2) and two transverse fixing plates (6), the two vertical fixing plates (2) are vertically and parallelly arranged, the two vertical fixing plates (2) are respectively and vertically fixed in the centers of the two transverse fixing plates (6), the two transverse fixing plates (6) are fixed on the upper surface of the base (7) through positioning bolts (9), the edges of the two transverse fixing plates (6) are parallel, the transverse fixing plates (6) are provided with a plurality of fixing plate limiting holes (5), the distance between the fixing plate limiting holes (5) is the same as that between the base limiting holes (8), and the distance D between the two transverse fixing plates (6) is adjusted by the positioning bolts (9) penetrating through the fixing plate limiting holes (5) and the base limiting holes (8) at different positions;

the inner sides of the two vertical fixing plates (2) are provided with a plurality of clamping rings (3) which are distributed at equal intervals in the vertical direction, the clamping rings (3) are divided into two rows and are respectively positioned at the vertical edges of the vertical fixing plates (2), the inner sides of the two vertical fixing plates (2) are horizontally provided with rotating shafts (4), two ends of each rotating shaft (4) respectively penetrate through the clamping rings (3) at two ends of the vertical fixing plates (2) and are positioned at the same horizontal height, the height of each rotating shaft (4) is adjusted through the clamping rings (3) which are inserted into the vertical fixing plates (2) and are different in height, two test piece supports are welded on each rotating shaft (4), and the test piece supports are positioned between the clamping rings (3) at two ends of each rotating shaft (;

a first rock test piece (1) and a second rock test piece (15) are respectively placed on the test piece supports of the two rotary shafts (4), and a film stress tester (12) is arranged on a contact surface between the two rock test pieces; the bottom of the first rock test piece (1) is connected with a displacement sensor (13) for testing the sinking displacement of the first rock test piece (1), a rock block loading disc at the bottom of the loading cross beam is tightly attached to the top of the first rock test piece (1), and the first rock test piece (1) is extruded by the rock block loading disc under the pressurization of the press machine.

2. The masonry beam structure block contact surface stress distribution form testing device according to claim 1, wherein: the base limiting hole (8) is a through hole.

3. The masonry beam structure block contact surface stress distribution form testing device according to claim 1, wherein: the clamping ring (3) is in an omega shape with two horizontal ends and a raised middle part, and the two ends are fixed on the inner side of the vertical fixing plate (2) through welding or bolts.

4. The masonry beam structure block contact surface stress distribution form testing device according to claim 1, wherein: the film stress tester (12) and the displacement sensor (13) are respectively connected with the computer (14) and transmit the measured data to the computer (14).

5. The masonry beam structure block contact surface stress distribution form testing device according to claim 1, wherein: the film stress tester (12) is positioned on the contact surface of the second rock test piece (15) or the first rock test piece (1).

6. The masonry beam structure block contact surface stress distribution form testing device according to claim 1, wherein: the test piece support comprises angle steel (11) and hinges (10), the hinges (10) are welded on the outer sides of the angle steel (11), and rotating shafts of the hinges (10) are welded on the rotating shafts (4).

Images