CN107389449A - A kind of filling in mine material compression property experimental provision and its experimental method - Google Patents

Abstract

The invention discloses an experimental device for the compression characteristics of mine filling materials and an experimental method thereof. The experimental device is placed on a press and includes a cavity containing the filling material. The piston is sealed, the bottom of the cavity is placed on the lower pressure plate of the press, and the pressure column connected to the piston is in contact with the upper pressure plate of the press; the outer wall of the cavity is attached with several rings at different axial positions. Strain gauges, hoop strain gauges are connected to static strain gauges, displacement sensors are also installed between the upper and lower pressure bearing plates of the press, and the static strain gauges and displacement sensors are respectively connected to the computer measuring system of the press through signals connect. The invention can monitor the compression amount of the filling material under different stresses and the strain of the outer wall of the steel cylinder through the measuring system of the press, has a simple structure and is easy to operate, and is suitable for the compression characteristics of filling bodies such as dry filling, water-sand filling and cemented filling. test.

Description

An experimental device and experimental method for compression characteristics of mine filling materials

technical field

The invention belongs to the field of mine filling and mining, and in particular relates to an experimental device for compression characteristics of mine filling materials and an experimental method thereof.

Background technique

The filling mining method not only has high safety, but also can effectively reduce ore loss, dilution and solve tailings stacking and pollution problems. It is also beneficial to mine air leakage, heat damage, rock burst, ore spontaneous combustion, coal and gas outburst and other disasters The prevention and control of it is widely used in various mines at present. The compression characteristics of filling materials affect the movement and deformation of stope surrounding rocks, and are important assessment indicators for mine filling quality. The greater the compression rate of the filling body, the greater the movement range of the rock formation and the longer the stable period, which is more unfavorable to the stability control of the surrounding rock. At present, scholars have carried out research on the bearing characteristics of 28d-age cemented filling bodies and made some progress, but few people have studied the compression characteristics of dry filling materials, water-sand filling bodies, and early-age cemented filling bodies. Not yet known. It can be seen that it is particularly necessary to study the compression characteristics of low-strength filling materials such as dry tailings in metal mines, tailings with different moisture contents, and cemented fillings with early-age tailings. Stope ground pressure management and filling process optimization are of great significance. At the same time, it can provide reference and reference for research on foundation gravel replacement and reinforcement in construction engineering and roadbed compaction in traffic engineering.

Chinese patent CN203053782U and Chinese patent CN105181463A respectively disclose a gangue filling experimental compression mold, a water-containing gangue compression experimental device and its experimental method, which are mainly aimed at testing the compression characteristics of dry gangue and water-containing gangue during dry filling in coal mines. However, the mine filling process also includes water-sand filling and cemented filling. The above-mentioned technical scheme is not suitable for filling materials such as tailings in metal mines, and does not consider the compression characteristics of early-age cemented filling bodies under the action of cementing materials. Frictional effects caused by confining pressure during confining compression.

Contents of the invention

The technical problem solved by the present invention is: aiming at the lack of devices for testing the confinement pressure of filling materials in the process of confinement compression in the prior art, an experimental device and an experimental method for the compression characteristics of mine filling materials can be provided, which can measure metal Compression (rate) of dry tailings or waste rock in mines, tailings with different moisture contents, and early-age tailings cemented fillings under different stresses and the confinement pressure on the cylinder wall.

The present invention adopts following technical scheme to realize:

An experimental device for compression characteristics of mine filling materials. The experimental device is placed on a press and includes a cavity containing filling materials. The bottom end of the cavity is provided with a bleeding structure, and the other end is sealed by a piston sliding in the cavity. , the bottom end of the cavity is placed on the lower pressure bearing plate of the press, and the piston is connected to the pressure bearing column and contacts the upper pressure bearing plate of the press through the pressure bearing column;

The outer wall of the cavity is attached with several hoop strain gauges at different axial positions, and the hoop strain gauges are connected with static strain gauges. There is a displacement sensor, and the static strain gauge and the displacement sensor are respectively connected with the computer connected with the measuring system of the press through signals.

Further, the cavity is composed of a top cover, a bottom cover and a steel cylinder with a chassis; the top cover and the bottom cover are coaxially fixed on both ends of the steel cylinder with a chassis respectively, wherein the center of the top cover is provided with a The guide hole through which the column passes, the bottom cover is fixedly overlapped with the chassis of the steel cylinder with a chassis, the inner cylinder of the steel cylinder with a chassis forms a closed cavity for filling materials, a number of bleeding holes are set on the bottom cover and The geotextile arranged between the bottom cover and the chassis with the chassis steel cylinder forms a bleeding structure.

Further, the top cover and the bottom cover are tensioned and fixed on both ends of the steel cylinder with a chassis through uniformly distributed circumferential screw assemblies; the top cover and the chassis of the steel cylinder with a chassis are respectively provided with a number of Corresponding through holes, several screw holes coaxial with the through holes are provided on the same circumference of the bottom cover, the screw assembly includes a screw rod and two sets of nuts, the screw rod passes through the coaxial through holes The hole is fixed and screwed, one set of nuts overlaps and locks the bottom cover and the chassis with the steel cylinder with the chassis, and the other set of nuts tightens the top cover and the bottom cover at both ends of the steel cylinder with the chassis.

Further, the inner wall of the steel cylinder with a chassis is polished and polished, the inner wall is coated with lubricating grease, and marked with scales along the axial direction.

Further, at least two O-rings are provided on the circumference of the piston, and the piston is in close contact with the inner wall of the steel cylinder with a chassis through the O-rings.

Further, the center of the top surface of the piston is provided with a groove having the same cross-section as the pressure-bearing column, one end of the pressure-bearing column fits in the groove, and the other end protrudes from the guide hole on the top cover.

Preferably, the hoop strain gauges are respectively arranged at 1/4, 1/2 and 3/4 height positions of the corresponding filling material.

In an experimental device for compression characteristics of mine filling materials according to the present invention, the press machine is a rock mechanics testing machine, and the displacement sensor is an LVDT displacement sensor.

The present invention also discloses an experimental method of the above-mentioned mine filling material compression characteristic experimental device, which specifically includes the following steps:

Step 1: First place the bottom cover on the flat ground, lay a geotextile on the bottom cover, place the steel cylinder with a chassis on the geotextile of the bottom cover, and let the through holes on the chassis of the steel cylinder correspond to the screw holes on the bottom cover , fix the bottom cover and the steel cylinder with chassis with nuts with screws;

Step 2: Apply lubricating grease to the inner wall of the steel cylinder with chassis, then evenly load the pre-weighed filling material into the steel cylinder, fill it to the experimental height, place the device assembled in step 1 on a concrete vibrating table and vibrate slightly to ensure The filling material is packed tightly;

Step 3: Put the piston with the O-ring seal into the steel cylinder with the chassis to be in close contact with the filling material, then put the pressure bearing column into the circular groove on the upper part of the piston, cover the top cover, and tighten the nut on the screw rod Fix the experimental device;

Step 4: Place the fixed experimental device between the upper and lower bearing plates of the rock mechanics testing machine, and install the LVDT displacement sensor between the upper and lower bearing plates;

Step 5: Symmetrically install hoop strain gauges at 1/4, 1/2 and 3/4 positions of the outer wall of the steel cylinder with chassis corresponding to the filling height of the filling material, and connect the hoop strain gauges to the static strain gauges;

Step 6: Debug the measurement system, displacement sensor and static strain gauge of the rock mechanics testing machine, and set the loading parameters and target conditions;

Step 7: Start the experiment, ensure that the measurement system of the rock mechanics testing machine, the displacement sensor and the static strain gauge are turned on synchronously, stop the experiment after reaching the target conditions, and use the computer to record and save the experimental data;

Step 8: Remove the experimental device, clean up the compacted filling material, sort out the experimental data and analyze the compression characteristics, and calculate the confinement pressure on the inner wall of the steel cylinder with the chassis by the following two formulas:

In the formula, q ₁ is the confining pressure on the inner wall of steel cylinder with chassis; σ _φ is the hoop stress on the outer wall of steel cylinder with chassis; a is the radius of inner wall of steel cylinder with chassis; b is the radius of outer wall of steel cylinder with chassis ;ε _φ is the hoop strain on the outer wall of the steel cylinder with chassis, μ is the Poisson's ratio of the steel cylinder with chassis, and E is the elastic modulus of the steel cylinder with chassis;

According to the corresponding hoop strain measured by the hoop strain gauges pasted at different positions on the outer wall of the steel cylinder with chassis, the hoop stress σ _φ can be obtained by using formula (2), and then brought into formula (1) to get the inner wall of the cylinder The confined pressure q ₁ , and then according to the friction coefficient, the friction force on the cylinder wall during the compression process can be obtained, and then the relationship between the compression characteristics and the confined friction force can be analyzed.

Further, if the filling material is a filling material containing cement, the experimental device with the filling material should also be placed in a constant temperature and humidity curing box for maintenance according to the underground climate environment.

Compared with the prior art, the present invention has the following beneficial effects:

(1) Simple structure

The device includes components such as a top cover, a bottom cover, a steel cylinder with a chassis, a pressure bearing column, a piston, and a screw rod. The components are closely connected, and the device is easy to disassemble. During the compression process, the components remain coaxially loaded, and the load is evenly transmitted to the filling material through the pressure-bearing column and the piston.

(2) Good sealing

There are at least two sealing ring grooves on the piston ring. The piston and the inner wall of the steel cylinder are in contact with the O-shaped rubber sealing ring. The sealing effect is good, and it is difficult for fine particles and compressed free water to overflow to the top of the piston during the compression process.

(3) Quantification of friction effect

When the piston is under pressure and in contact with the filling material, the friction between the piston and the inner side of the cylinder wall cannot be ignored. In order to reduce the friction effect, in addition to installing a sealing ring on the piston ring, the inner wall of the cylinder is polished and polished, and lubricating grease is applied before the experiment. According to the strain on the outside of the cylinder wall, the confinement pressure on the inside of the cylinder wall during the compression process can be obtained, which realizes the quantification of the friction effect.

(4) Wide application range

In addition to testing the compression characteristics of dry tailings in metal mines, tailings with different moisture contents and tailings cemented bodies of different ages, the device can also test small-scale waste rocks, fly ash, cement and other cementitious materials and The compressive properties of foundation crushed stone in construction engineering and roadbed filling in traffic engineering are tested.

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic structural diagram of the experimental device for compressive properties of mine filling materials in the embodiment.

Fig. 2 is a top view of the top cover in the embodiment.

Fig. 3 is a top view of the steel cylinder with chassis in the embodiment.

Fig. 4 is a top view of the bottom cover in the embodiment.

Fig. 5 is a top view of the piston in the embodiment.

Fig. 6 is a schematic diagram of the test system connection of the test device for the compression characteristics of the mine filling material in the embodiment.

Fig. 7 is a stress compressibility characteristic curve in the embodiment.

Fig. 8 is a curve showing the relationship between the confining pressure and the vertical loading stress during the compression process in the embodiment.

Symbols in the figure: 1—circular pressure bearing column, 2—nut, 3—groove, 4—O-ring, 5—piston, 6—filling material, 7—bottom cover, 8—blind screw hole, 9— Guide hole, 10—through hole, 11—top cover, 12—steel cylinder with chassis, 13—circular strain gauge, 14—screw, 15—geotextile, 16—bleeding hole, 17—LVDT displacement sensor, 18— Upper pressure plate of rock mechanics testing machine, 19—compression test device, 20—static strain gauge, 21—measurement system of rock mechanics testing machine, 22—lower pressure bearing plate of rock mechanics testing machine, 23—computer.

detailed description

Example

Referring to Figures 1-6, a mine filling material compression characteristic experimental device in the illustration is the preferred solution of the present invention, specifically including a circular pressure bearing column 1, a nut 2, a sealing ring 4, a piston 5, a bottom cover 7, a top Cover 11, steel cylinder with chassis 12, hoop strain gauge 13, screw rod 14, geotextile 15 and other components.

Wherein, the bottom cover 7, the top cover 11 and the steel cylinder 12 with a chassis form a cavity for filling the filling material 6, and the main body of the cavity is a cylindrical inner chamber with a steel cylinder 12 with a chassis, and the bottom of the steel cylinder 12 with a chassis and The bottom cover 7 is equipped with a bleeding structure to ensure the water discharge of the filling material during the compression process. The top is fixed to the top cover 11, and a piston 5 is installed in the inner cavity of the steel cylinder. The inner wall of the cylinder slides, and the device constituting the cavity is placed vertically on the press. The press of this embodiment adopts a rock mechanics testing machine, wherein the bottom cover 7 is placed on the lower pressure plate 22 of the rock mechanics testing machine, and the piston 5 passes through the circle. The shaped pressure column 1 is connected with the upper pressure plate 18 of the external rock mechanics testing machine, and transmits the pressure load to the filling material in the cavity.

Specifically as shown in Figure 6, a number of circumferential strain gauges 13 are arranged on the outer wall of the steel cylinder 12 with a chassis to detect the strain caused to the steel cylinder wall during the compression test of the filling material, and use elastic mechanics to solve the problem according to the measured strain Confining pressure on the inner wall, in this embodiment, three sets of hoop strain gauges 13 are arranged at different axial positions on the outer wall of the steel cylinder with a chassis, preferably at 1/4, 1/2 and 3/4 height positions of the corresponding filling materials, The three groups of hoop strain gauges 13 are respectively connected to the static strain gauges 20 through signal lines. In addition, an LVDT displacement sensor 17 is provided between the upper pressure plate 18 of the rock mechanics testing machine and the lower pressure plate 22 of the rock mechanics testing machine to detect the compression displacement during the compression process of the filling material, the LVDT displacement sensor 17 and the static strain The instrument 20 is respectively connected to the computer 23 connected to the rock mechanics testing machine measurement system 21 through signal lines, and the software installed on the computer 23 inputs measurement parameters and calculates and displays the measurement parameters collected by the sensor. The calculation software for the filling material is commonly used data processing software in existing rock mechanics experiments, and will not be described in detail here in this embodiment.

Specifically, the steel cylinder 12 with a chassis is a cylindrical member, and a flange chassis is provided at the bottom thereof, and the top cover 11 and the bottom cover 7 are respectively coaxially fixed on the two ends of the steel cylinder 12 with a chassis, wherein the center of the top cover 11 is provided with a The guide hole 9 through which the pressure-bearing column embedded with the piston passes, the bottom cover 7 is fixedly overlapped with the chassis with the chassis steel cylinder 12, five groups of bleeding holes 16 are arranged on the bottom cover 7, and a Layer geotextile 15, and then fix the chassis with chassis steel cylinder 12 and bottom cover 7 to compress the geotextile, the bleeding hole 16 and geotextile 15 together form a bleeding structure, and the geotextile 15 can avoid filling material fine particles during compression The loss of the filling material can also ensure that the moisture inside the filling material is compressed and discharged.

The top cover 11 and the bottom cover 7 are tightened and fixed on both ends of the steel cylinder 12 with a chassis by four sets of screw assemblies evenly distributed in the circumferential direction. As shown in Fig. 2, Fig. 3 and Fig. 4 specifically, four groups of one-to-one through-holes 10 are respectively arranged along the same circumference on the edge of the chassis of the top cover 11 and the steel cylinder with chassis 12, and the same circumference of the bottom cover 7 is provided with There are four groups of blind screw holes 8 that are coaxial with the through holes respectively, and each group of screw components includes a screw rod 14 and two groups of nuts 2, the bottom cover 7 and the steel cylinder with chassis 12 are positioned coaxially, and the four screw rods 14 are coaxially positioned. One end passes through the through hole 10 of the chassis with the chassis steel cylinder 12 in turn and is fixed and screwed to the blind screw hole 8 on the bottom cover 7, and the bottom cover 7 and the chassis with the chassis steel cylinder 12 are overlapped and locked by one set of nuts. The other end of the screw rod passes through the through hole 10 on the top cover 11, and another set of nuts 2 is screwed on the screw rod above the top cover 7, and the top cover and the bottom cover are tightened and fixed on the two ends of the steel cylinder with a chassis, and the device is completed. structural assembly. When carrying out the filling material experiment, first screw one end of the screw into the blind screw hole of the bottom cover to fix the bottom cover and the steel cylinder with chassis, then after filling the inside of the steel cylinder, cover the top cover, and then tighten the screw with nuts The other end secures the entire unit.

As shown in Figure 5, the center of the top surface of the piston 5 is provided with a circular groove 3 having the same cross-section as the circular pressure-bearing column 1. The guide hole 9 on the 11 stretches out. The piston 5 is located in the steel cylinder 12 with a chassis and placed above the filling material 6 at a certain height. The circumference of the piston 5 is provided with at least two rings of O-rings 4 , and the O-rings 4 are connected to the steel cylinder 12 with a chassis. close contact with the inner wall. The inner wall of the steel cylinder 12 with a chassis is polished and polished, the inner wall is coated with lubricating grease, and marked with scales along the axial direction, and is used for loading quantitative filling materials.

In the actual processing and assembly process, the axes of the top cover 11, the bottom cover 7, the steel cylinder with chassis 12, the piston 5 and the circular pressure bearing column 1 are on the same straight line, and the materials are all 45# hardened steel. The diameter of the piston 5 is 1 mm smaller than the inner diameter of the steel cylinder 12 with a chassis, and there are two grooves distributed in the piston ring direction, and the O-ring is installed in the grooves, so that the piston 5 is in close contact with the inner wall of the steel cylinder with a chassis, and the circular The diameter of the pressure-bearing column 1 is equal to the diameter of the groove 3 on the piston, which is 2mm smaller than the diameter of the guide hole 9 on the top cover 11. The upper part of the circular pressure-bearing column passes through the circular guide hole of the top cover and bears pressure on the rock mechanics testing machine. plate contact transfer load

The implementation process of this embodiment will be described in detail below in conjunction with a specific experimental process.

Top cover 11 diameter among the present embodiment is 305mm, and thickness is 10mm, and the diameter that leaves circular guide hole 9 in the center is 52mm, leaves four circular through holes 10 required for screw rod 14 fixtures around the top cover, The diameter of the through hole is 10mm.

The chassis with chassis steel cylinder 12 is welded on the steel cylinder, considering the requirement that the height-to-diameter ratio of the filling material sample is not less than 2 and the ratio of the inner diameter of the cylinder to the maximum particle diameter is more than 3 to 5 times, the diameter of the inner wall of the steel cylinder is 105mm, and the height 250mm, wall thickness 10mm, chassis thickness 10mm. The inner wall of the steel cylinder is marked with a scale, and the inner wall has been polished and polished. The outer diameter of the steel cylinder chassis is 305mm, and four through holes with a diameter of 10mm are evenly opened with the top cover 11 on it. Three sets of hoop strain gauges 13 are symmetrically attached to the outer wall of the steel cylinder 12 with a chassis along the 1/4, 1/2 and 3/4 positions of the filling material filling height (210 mm).

Five bleeding holes 16 with a diameter of 5 mm are evenly distributed in the center of the bottom cover 7, and blind screw holes corresponding to the through holes 10 of the steel cylinder with a chassis are evenly distributed on the edge, with a diameter of 5 mm and a depth of 5 mm. The diameter of the bottom cover 7 is 305 mm, and the thickness is 10 mm. A layer of geotextile 15 is laid between the bottom cover 7 and the chassis with the steel cylinder 12 of the chassis.

The diameter of the piston 5 is 49 mm, and the thickness is 20 mm. There are two grooves distributed in the circumferential direction of the piston. An O-shaped sealing ring 4 is installed in the groove to make the piston 5 closely contact with the inner wall of the steel cylinder 12 with a chassis. The top surface of the piston 5 is provided with a The groove 3 has an inner diameter of 50mm and a depth of 2mm.

The circular pressure-bearing column 1 passes through the guide hole 9 on the top cover 11, the bottom part is embedded with the groove 3 on the piston 5, and the upper part is in contact with the pressure-bearing plate 18 on the rock mechanics testing machine. The diameter of the circular pressure-bearing column 1 is is 50mm and the height is 200mm.

The screw rod 14 is threaded throughout the length, and one end is screwed into the blind screw hole 8 on the bottom cover to tighten the bottom cover 7 and the steel cylinder 12 with the chassis with the nut 2, and the filling material 6 is installed in the steel cylinder to the designed height before covering Put on the top cover 11, and then tighten the nut 2 at the other end of the screw rod 14 to fix the top cover 11 on the top of the steel cylinder, so as to realize the fixing of the whole device;

Top cover 11, bottom cover 7, steel cylinder with chassis 12, piston 5 and pressure bearing column 1 are made of 45# hardened steel with elastic modulus of 210GPa and Poisson's ratio of 0.23.

The compression test device 19 is placed between the upper bearing plate 18 of the rock mechanics testing machine and the lower bearing plate 22 of the rock mechanics testing machine. 18 and the LVDT displacement sensor 17 at the height between the lower bearing plate 22 and the static strain gauge 20 for measuring strain at different positions on the outer wall of the steel cylinder. When the filling material contains cement, a constant temperature and humidity curing box is required for pre-curing.

The specific steps of the experimental process are as follows:

Step 1: First place the bottom cover on the flat ground, lay a geotextile on the bottom cover, place the steel cylinder with a chassis on the geotextile of the bottom cover, make the through holes on the chassis of the steel cylinder and the blind screw holes on the bottom cover one by one Correspondingly, use screws to fix the bottom cover and steel cylinder with chassis with nuts;

Step 2: Apply lubricating grease, such as emulsified oil, to the inner wall of the steel cylinder with a chassis, then evenly load the pre-weighed filling materials into the steel cylinder, and after filling to the experimental height, place the device assembled in step 1 on the concrete vibrating table slightly Vibrate to ensure that the filling material is packed tightly, and the height of the filling material after vibration is not less than 210mm;

Step 3: Put the piston with the O-ring seal into the steel cylinder with the chassis to be in close contact with the filling material, then put the pressure bearing column into the circular groove on the upper part of the piston, cover the top cover, and tighten the nut on the screw rod Fix the experimental device; if the compression characteristics of the filling material containing cement are studied, the experimental device with the filling material needs to be placed in a constant temperature and humidity curing box for maintenance according to the underground climate environment. This step is ignored when experimenting with filling materials without cement.

Step 4: Place the fixed experimental device between the upper and lower bearing plates of the rock mechanics testing machine, and install the LVDT displacement sensor between the upper and lower bearing plates;

Step 5: Symmetrically install hoop strain gauges at 1/4, 1/2 and 3/4 positions of the outer wall of the steel cylinder with chassis corresponding to the filling height of the filling material, and connect the hoop strain gauges to the static strain gauges;

Step 6: Debug the measurement system, displacement sensor and static strain gauge of the rock mechanics testing machine, and set the loading parameters and target conditions;

Step 7: Start the experiment, ensure that the measurement system of the rock mechanics testing machine, the displacement sensor and the static strain gauge are turned on synchronously, stop the experiment after reaching the target conditions, and use the computer to record and save the experimental data;

Step 8: Remove the experimental device, clean up the compacted filling material, organize the experimental data and analyze the compression characteristics, and calculate the confining pressure on the inner wall of the steel cylinder with the chassis through the following calculation process:

According to the compression rate of the filling material under different stresses measured by the test system, the stress-compression rate characteristic curve of the filling material can be obtained. It should be noted that the confinement pressure will produce a significant friction effect during the compression process. When analyzing the compression deformation characteristics and energy consumption characteristics of filling materials, the role of friction force cannot be ignored. According to the Lamé solution formula for cylinder compression in elastic mechanics:

In the formula, q ₁ is the pressure on the inner wall of the steel cylinder with a chassis; q ₂ is the pressure on the outer wall of the steel cylinder with a chassis; σ _ρ is the radial stress on the steel cylinder with a chassis; σ _φ is the steel cylinder with a chassis hoop stress; a is the inner radius of the steel cylinder with chassis; b is the outer radius of the steel cylinder with chassis; ρ is the distance from the inner point of the wall of the steel cylinder with chassis to the axis;

In the test, since the outer wall of the steel cylinder with a chassis is not stressed, that is, q ₂ is 0, and the steel cylinder with a chassis is only affected by the pressure on the inner wall, so the radial stress σ _ρ on the outer wall of the steel cylinder is 0 from formula (1), and only There is a hoop stress σ _φ , and at the same time ρ=b, formula (2) is simplified as:

The deformation problem of the steel cylinder belongs to the plane strain problem, which is expressed by Hooke's law in polar coordinates:

In the formula, ε _φ is the hoop strain on the outer wall of the steel cylinder with chassis, μ is the Poisson’s ratio of the steel cylinder with chassis, and E is the elastic modulus of the steel cylinder with chassis.

According to the corresponding hoop strain measured by the hoop strain gauges 13 pasted at different positions on the outer wall of the steel cylinder with chassis, the average hoop stress σ _φ can be obtained by using formula (5), and then brought into formula (4) to get the circle The confining pressure q ₁ on the inner wall of the cylinder, and then the friction force on the cylinder wall during the compression process can be obtained according to the friction coefficient.

Taking the water-sand filling in the second-step stope of Sanshandao Gold Mine as the engineering background, experiments on the compression characteristics of tailings under different water contents were carried out. The tailings are graded tailings (-37μm) from the dressing plant. The dry density of the tailings measured indoors is 2.55g/cm ³ , the specific surface area is 104m ² /kg, the coefficient of inhomogeneity is 5.77, and the coefficient of curvature is 1.63, indicating that the tailings The degree distribution is uneven, and the gradation continuity is good. The experiment under the condition of 12% moisture content is selected from the tailings compression characteristics experiment with different moisture content as an example to illustrate. The experiment is controlled by the continuous loading method, the target stress is 30MPa, and the loading speed is 4kN/s, and the distribution obeys the exponential function. The characteristic curve of stress compressibility is shown in Fig. 7. The average hoop strain measured by the three sets of hoop strain gauges on the outer wall of the steel cylinder is brought into equations (5) and (4) to calculate the confinement pressure during compression, and based on the time synchronization relationship, the confinement pressure and The corresponding relationship curve of vertical loading stress is shown in Figure 8. It can be seen from the figure that the confinement pressure and the vertical loading stress are approximately in a proportional function relationship, the slope, that is, the lateral pressure coefficient is 1.4, and the friction coefficient between 45# quenched steel and rock particles under emulsified oil lubrication is 0.25, which can be calculated as 12%. Confinement pressure and friction of tailings under different stresses under moisture content. Similarly, the compressibility, confinement pressure, and friction of filling bodies under different stresses with other moisture contents and cement-containing conditions can be achieved by referring to the above-mentioned experimental procedures.

The above embodiment has described the basic principle of the present invention and main feature and the advantage of the present invention, those skilled in the art should understand that the present invention is not limited by the above embodiment, and what described in the above embodiment and description is only to illustrate the present invention The specific working principle, under the premise of not departing from the spirit and scope of the present invention, the present invention also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed invention, and the claimed protection scope of the present invention is defined by the appended The claims and their equivalents are defined.

Claims (10)

1. A kind of 1. filling in mine material compression property experimental provision, it is characterised in that：The experimental provision is placed on forcing press, bag Include the cavity for containing filler, the bottom of the cavity sets bleeding structure, the other end by the piston seal that is slided in cavity, Wherein, the bottom of the cavity is placed on the lower bearing plate of forcing press, and the piston connects pressure-bearing post and by pressure-bearing post and pressure The upper bearing plate contact of power machine；

   The outer wall of the cavity is sticked in axially different position some hoop strain pieces, the hoop strain piece and static strain Instrument is connected, and displacement transducer, the statical strain indicator and position are additionally provided between the upper bearing plate of the forcing press and lower bearing plate The computer that displacement sensor is connected with forcing press measuring system respectively is connected by signal.
2. 2. a kind of filling in mine material compression property experimental provision according to claim 1, the cavity is by top cover, bottom Formed with band chassis steel cylinder；

   The top cover and bottom are coaxially fixed on the both ends with chassis steel cylinder respectively, and wherein the center of top cover, which is provided with, is used for pressure-bearing post The pilot hole passed through, the bottom is overlapping with the chassis fixation with chassis steel cylinder, and the inner cylinder with chassis steel cylinder, which is formed, to be contained Set between the cavity of filler, some bleeding holes set on the bottom and the bottom and chassis with chassis steel cylinder The geotextiles put form bleeding structure.
3. 3. a kind of filling in mine material compression property experimental provision according to claim 2, the top cover and bottom pass through Circumferential equally distributed screw arbor assembly is strained and fixed at the both ends with chassis steel cylinder；

   The top cover and chassis with chassis steel cylinder are provided with some one-to-one through holes along same circumference respectively, the bottom Same circumference is provided with some screws coaxial with through hole respectively, and the screw arbor assembly includes screw rod and two groups of nuts, the spiral shell Bar is through coaxial through hole and fixes and is spirally connected with screw, and one of which nut is by bottom lock overlapping with the chassis with chassis steel cylinder Tightly, top cover and bottom are strained and fixed at the both ends with chassis steel cylinder by another group of nut.
4. 4. a kind of filling in mine material compression property experimental provision according to claim 3, described with the steel cylinder of chassis The processing of wall polishing grinding, inwall is coated with lubricant grease, and in axial direction indicates scale.
5. 5. a kind of filling in mine material compression property experimental provision according to claim 4, the circumference ring of the piston Provided with least two circle O-ring seals, the piston is in close contact by O-ring seal and the inwall with chassis steel cylinder.
6. 6. a kind of filling in mine material compression property experimental provision according to claim 5, the end face center of the piston Provided with pressure-bearing column section identical groove, described pressure-bearing post one end is chimeric in a groove, and the other end is from the pilot hole on top cover Stretch out.
7. 7. a kind of filling in mine material compression property experimental provision according to claim 1, the hoop strain piece difference It is arranged in 1/4,1/2 and 3/4 height and position that steel cylinder outer wall corresponds to filler.
8. 8. a kind of filling in mine material compression property experimental provision according to any one of claim 1-7, the pressure Machine is rock mechanics experiment machine, and institute's displacement sensors are LVDT displacement transducers.
9. 9. a kind of a kind of experimental method of filling in mine material compression property experimental provision described in right 1-8, its feature exist In comprising the following steps：

   Step 1：First bottom is placed on level land, geotextiles are laid on bottom, band chassis steel cylinder is placed on bottom geotextiles On, the screw allowed on through hole and bottom on steel cylinder chassis corresponds, and is consolidated with screw rod by bottom and with chassis steel cylinder with nut Get up calmly；

   Step 2：In the inwall coating lubricating oil fat with chassis steel cylinder, filler weighted in advance is uniformly then loaded into steel Cylinder, is loaded into the device for assembling step 1 after high experimental and is placed on concrete vibrating stand and slightly vibrate, and ensures filler dress Packing is real；

   Step 3：The piston for being provided with O-ring seal is put into the steel cylinder of band chassis and is in close contact with filler, then will be held Compression leg is put into upper piston area circular groove, top cover, and the nut tightened on screw rod fixes experimental provision；

   Step 4：Between the experimental provision fixed is placed on into the upper and lower bearing plate of rock mechanics experiment machine, in upper and lower bearing plate Between install LVDT displacement transducers；

   Step 5：Symmetrically it is sticked ring in 1/4,1/2 and 3/4 opening position that filler filling height is corresponded to chassis steel cylinder outer wall It is connected to foil gauge, and by hoop strain piece with statical strain indicator；

   Step 6：Rock mechanics experiment machine measuring system, displacement transducer and statical strain indicator are debugged, loading parameter and mesh are set Mark condition；

   Step 7：Start to test, ensure that rock mechanics experiment machine measuring system, displacement transducer and statical strain indicator are synchronously opened, Stop experiment after reaching goal condition, experimental data is recorded and preserved using computer；

   Step 8：Experimental provision is removed, the filler after cleaning compacting, experimental data is arranged and carries out compression property analysis, and By following two formula calculate with chassis steel cylinder inwall suffered by confining pressure：

   In formula, q₁For the confining pressure suffered by with chassis steel cylinder inwall；σ_φFor the circumference stress suffered by with chassis steel cylinder inwall；A is Band chassis steel cylinder inwall radius；B is band chassis steel cylinder exterior radius；ε_φFor the hoop strain suffered by with chassis steel cylinder outer wall, μ is Band chassis steel cylinder barrel Poisson's ratio, E are band chassis steel cylinder barrel modulus of elasticity；

   Hoop strain piece according to being pasted with chassis steel cylinder outer wall diverse location measures corresponding hoop strain, can using formula (2) Obtain circumference stress σ_φ, then bring formula (1) into and can try to achieve confining pressure q suffered by cylinder inner wall₁, can be asked further according to coefficient of friction Go out the frictional force suffered by barrel in compression process, and then analyze the relation between compression property and lateral spacing frictional force.
10. A kind of 10. experimental method of filling in mine material compression property experimental provision according to claim 9, if filling material Expect for the filler containing cementitious matter, the experimental provision equipped with filler also is put into constant-temp. and-moisture maintenance according to underground Climatic environment is conserved.