CN101308126A - A test method and device for underwater mining roof seepage and water inrush - Google Patents

Abstract

The invention discloses a test method and device for underwater mining roof seepage and water inrush. The steps are as follows: (1) placing the configured test materials in a model box according to the actual relative positions; (2) adjusting the model in the model box The material exerts lateral pressure; (3) seal the top of the model box, and apply a set water pressure on the top of the model; (4) collect water pressure data, structural stress data, and displacement digital data at regular intervals during the excavation process; Photos, digital photos of cracks with a certain magnification, until the water inrush damage occurs during excavation; (5) Repeat steps (1), (2), (3) to change the lateral pressure and water pressure parameters, and repeat step (4); (6) Obtain the relationship between top water pressure, structural stress, model surface displacement and model surface cracks. The invention can more truly reflect the joint action of the structural stress, the top water pressure and the self-weight of the covering layer, thereby improving the test accuracy.

Description

A test method and device for underwater mining roof seepage and water inrush

technical field

The invention mainly relates to the field of test models for underwater mining, in particular to a test method and device for seepage and water inrush on roof plates of underwater mining.

Background technique

With the rapid development of the economy, the demand for various mineral resources is strong, which promotes the rapid development of the mining industry. The huge and continuous demand, and the resource constraints that have begun, have led people to start betting on underwater ore mining. Underwater mining is a kind of ore body that is difficult to mine. Underwater mining technology, especially seabed mining, needs further research. One of the key issues is the research on the mechanism and control technology of underwater mining roof water inrush. The consequences of underwater mining roof water inrush are unimaginable, and its research is of great significance to the safe and efficient mining of underwater mining and the critical mining height. In the current situation where ore deposits are becoming more and more scarce, it is of great significance to reasonably determine the critical mining thickness for improving the mining rate of ore deposits.

The seepage of water in rock mass fissures is very complicated. The stress state of the rock mass and the distribution of joints have an important impact on the anisotropy of the rock mass and the seepage of the rock mass. Conversely, the seepage of the rock mass will affect the safety of underwater mining. It may cause seepage and water inrush damage to the roof. General model tests can only study the influence of structural stress and top pressure on roadway stability, but cannot study the generation and formation process of roof water inrush, and then study the impact of roof water inrush on mine safety. Liu Xinhe (similar simulation research experiment of underwater ore deposit mining) experimental research thinks that the tension fracture is the main channel of water inrush. The defect of this method is that it does not consider the influence of fluid-solid coupling effect, which is very different from the actual situation of water inrush damage. First of all, because the existence of water accelerates the seepage damage of the upper covering layer, the static and dynamic properties of water, as well as the adverse effects of water seepage damage are not considered, and the mine safety assessment that does not consider the impact of water is unsafe. Second, It is because there is no influence of the introduction of water, and it cannot reflect the damage process of roof water inrush vividly, intuitively and truly. The general model test has the above two major defects, and the simulation research on the key problem of roof water inrush in underwater mining is not ideal, and needs to be perfected and improved.

Using similar model tests to study roof water inrush tests should consider water-solid coupling, study the occurrence and development of cracks and the formation of water inrush channels from the macro and micro perspectives, and the displacement and stress distribution characteristics of mining surrounding rock and overlying layers , so as to reveal the roof water inrush mechanism and roof water inrush criterion; study the influence of tectonic stress and water pressure at the top of the ore body on seepage water inrush damage, and provide an experimental basis for roof water inrush prevention and control technology. Traditional measurement methods are not convenient for measuring the distribution of model cracks and displacements, and advanced measurement techniques should be used to ensure that the test devices and test methods can be realized. At the same time, various aspects ensure that the test meets the waterproof requirements and prevents artificial water inrush and leakage. Explain the relationship between roof water inrush and water pressure tectonic stress.

Contents of the invention

The problem to be solved by the present invention is that: in view of the technical problems existing in the prior art, the present invention provides an underwater mining method that can more truly reflect the combined effects of structural stress, top water pressure, and overburden self-weight, thereby improving the accuracy of the test. Roof seepage water inrush test method and device.

In order to solve the above-mentioned technical problems, the solution proposed by the present invention is: a test method for seepage and water inrush on the roof of underwater mining, the steps of which are as follows:

(1) Build a model box: Utilize the similarity ratio to configure the model material for the test, and place the configured test material in the model box according to the actual relative position. In a preferred embodiment, the middle and upper part of the model material and the model box can The side is filled with silica gel to achieve the purpose of waterproofing, ensuring that water will not flow out along both sides of the model box during the test;

(2) Apply lateral pressure: apply lateral pressure to the model material in the model box, and keep the lateral pressure constant during the test;

(3) Apply water pressure: seal the top of the model box, and apply a set water pressure on the top of the model to simulate the influence of water pressure on the top of the underwater mining;

(4) Model excavation: According to the requirements of the test design, model excavation is carried out to simulate the excavation of underwater ore bodies; The surface crack observation device collects water pressure data, structural stress data, digital photos of displacement, and digital photos of cracks enlarged by a certain number of times at regular intervals until water inrush damage occurs during excavation;

(5) Repeat steps (1), (2), (3) to change lateral pressure, water pressure parameters, and repeat step (4);

(6) Use corresponding analysis software for displacement analysis and crack analysis to obtain the relationship between top water pressure, structural stress, model surface displacement and model surface cracks.

An underwater mining roof seepage water inrush test device is characterized in that it includes a model box (1) fixed on a pedestal, a lateral pressure applying mechanism, a top water pressure applying mechanism, a control mechanism, and a model surface displacement and deformation measuring mechanism , a model surface crack observation mechanism and a computer, the top water pressure applying mechanism is located on the top of the model box, the lateral pressure applying mechanism is installed on the two sides of the model box, the model surface displacement and deformation measuring mechanism connected with the computer and the model surface The crack observation mechanism is respectively installed in the front and rear of the model box.

The lateral pressure applying mechanism includes more than two telescopic driving devices located on both sides of the model box. One end of the telescopic driving device is connected to the movable side plate located in the model box, and the other end is fixed on the pedestal through the reaction frame. The telescopic driving device Controlled by the control mechanism.

The model surface displacement and deformation measurement mechanism includes a first image acquisition device, and the model surface crack observation mechanism includes a second image acquisition device and a microscope, and the first image acquisition device and the second image acquisition device are respectively located directly in front of and directly in front of the model box. At the rear, the first image acquisition device and the second image acquisition device are connected to the computer (22).

The water pressure applying mechanism includes a water pressure measuring tube with a scale and two water body range regulating plates used to adjust the water body range on the top of the model box, and the water pressure measuring tube is inserted between the two water body range regulating plates to form a in the waters.

Compared with the prior art, the advantage of the present invention is that: the present invention proposes to comprehensively consider the structural stress, top water pressure, displacement and crack changes to obtain the water inrush criterion, which is more accurate than the water inrush criterion obtained only by considering the structural stress and displacement. Reasonable, more in line with the actual situation of the project. On the basis of this test method, the present invention proposes a corresponding test device. Compared with other devices, this device can realize the joint action of structural stress and bottom water pressure. By analyzing digital photos, the model displacement and crack changes can be obtained. Thereby improving the accuracy and depth of measurement.

Description of drawings

Fig. 1 is a schematic flow sheet of the inventive method;

Fig. 2 is the front view structure schematic diagram of device of the present invention;

Fig. 3 is the side view structural representation of device of the present invention;

Fig. 4 is the top view structural representation of device of the present invention;

Fig. 5 is the schematic diagram of the 1/4 width water body of the model test in the specific embodiment;

Fig. 6 is the schematic diagram of the full width water body of the model test in the specific embodiment;

Fig. 7 is the distribution schematic diagram that model test applies uniform lateral pressure in specific embodiment;

Fig. 8 is a schematic diagram of the distribution of the linear side pressure applied in the model test in the specific embodiment;

Fig. 9 is a schematic diagram of a geological section along the ore body strike in a specific embodiment;

Fig. 10 is a schematic diagram of a geological section along the vertical ore body strike in a specific embodiment.

illustration

1. Model box 2. Pedestal

3. Model box skeleton 4. Reaction frame

5. Movable side panels 6. Telescopic driving device

7. Water body range adjustment plate 8. Water pressure pressure measuring tube

9. Pressure measuring tube scale 10. Pressure measuring tube bracket

11. Control mechanism 12. High pressure oil pressure pipeline

13. Anchor bolts 14. Fixing bolts

15. Lower base plate 16. Upper base plate

17. The first image acquisition device 18. Digital camera tripod

19. Microscope 20. Second image acquisition device

21. Microscope stand 22. Computer

23. Water collector

Detailed ways

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

As shown in Figure 1, a kind of underwater mining roof seepage water inrush test method of the present invention, its steps are:

(1) Build a model box: Utilize the similarity ratio to configure the model material for the test, and place the configured test material in the model box according to the actual relative position. In a preferred embodiment, the middle and upper part of the model material and the model box can The side is filled with silica gel to achieve the purpose of waterproofing, ensuring that water will not flow out along both sides of the model box during the test;

(2) Apply lateral pressure: apply lateral pressure to the model material in the model box, and keep the lateral pressure constant during the test;

(3) Apply water pressure: seal the top of the model box, and apply a set water pressure on the top of the model to simulate the influence of water pressure on the top of the underwater mining;

(4) Model excavation: According to the requirements of the test design, model excavation is carried out to simulate the excavation of underwater ore bodies; The surface crack observation device collects water pressure data, structural stress data, digital photos of displacement, and digital photos of cracks enlarged by a certain number of times at regular intervals until water inrush damage occurs during excavation;

(5) Repeat steps (1), (2), (3) to change lateral pressure, water pressure parameters, and repeat step (4);

(6) Use corresponding analysis software for displacement analysis and crack analysis to obtain the relationship between top water pressure, structural stress, model surface displacement and model surface cracks.

As shown in Fig. 2, Fig. 3 and Fig. 4, a kind of underwater mining roof seepage water inrush test device of the present invention includes a model box 1 fixed on a pedestal 2, a lateral pressure applying mechanism, and a top water pressure applying mechanism , control mechanism 11, model surface displacement deformation measurement mechanism, model surface crack observation mechanism and computer 22, wherein the model box 1 is equipped with a model material that utilizes the configuration of the similarity ratio, and can be placed on the middle and upper parts of the model material and the model box 1 both sides Fill it with silica gel to achieve the purpose of waterproofing and ensure that water will not flow out along both sides of the model box 1 during the test. At the same time, the bottom of the model box 1 is equipped with a water collector 23 to collect the water flow caused by seepage and water inrush damage on the roof. The top water pressure applying mechanism is located on the top of the model box 1, the lateral pressure applying mechanism is installed on both sides of the model box 1, and the model surface displacement deformation measurement mechanism and the model surface crack observation mechanism connected to the computer 22 are respectively installed on the model box. Box 1 is directly in front and directly behind.

The lateral pressure applying mechanism includes more than two telescopic driving devices 6 located on both sides of the model box 1, one end of the telescopic driving device 6 is connected to the movable side plate 5 located in the model box 1, and the other end is fixed to the pedestal 2 through the reaction force frame 4 Above, the telescopic driving device 6 is controlled by the control mechanism 11 . The telescopic driving device 6 can adopt electric or hydraulic methods as required. In this embodiment, the telescopic driving device 6 adopts four hydraulic cylinders, and two hydraulic cylinders are respectively symmetrically arranged on both sides of the model box 1, and the hydraulic cylinders pass through the high-pressure hydraulic pipeline. 12 is connected with the servo console as control mechanism 11, and is controlled by it. The reaction force frame 4 is fixed on the upper base plate 16 and the lower base plate 15 on the pedestal 2 through the anchor bolts 13 , and the hydraulic cylinder is fixed on the reaction force frame 4 through the fixing bolts 14 . In a preferred embodiment, the two sides of the model box 1 are sealed with silica gel to ensure that water will not flow out along the gap at the movable side plate 5 during the test.

The model surface displacement and deformation measurement mechanism includes a first image acquisition device 17, and the model surface crack observation mechanism includes a second image acquisition device 20 and a microscope 19, and the first image acquisition device 17 and the second image acquisition device 20 are respectively positioned at the front of the model box 1. Front and rear, the first image acquisition device 17 and the second image acquisition device 20 are connected to a computer 22 . In the present embodiment, the first image acquisition device 17 adopts a high-resolution digital camera, and is fixed on the front of the model box 1 by a digital camera tripod 18. During the test, digital photos of the model surface are taken at regular intervals, and the digital photos are taken through the computer 22. The analysis software of the model obtains the relationship between the surface displacement of the model, the top water pressure, and the structural stress. The second image acquisition device 20 adopts CCD, and the microscope 19 adopts a stereomicroscope, and the stereomicroscope is fixed on the right rear of the model box 1 by the microscope support 21. During the test, the digital photos of the model surface are taken at regular intervals, and are passed through the computer 22. The analysis software obtains the relationship between the distribution, width and length of cracks on the surface of the model, the water pressure at the top, and the structural stress.

The water pressure applying mechanism includes a water pressure measuring tube 8 with a scale and two water body range adjusting plates 7 for adjusting the water body range on the top of the model box 1, and the water pressure measuring tube 8 is inserted between the two water body range adjusting plates 7 in the waters formed between them. A water collector for collecting the water flow generated after the water inrush is destroyed can further be arranged at the bottom of the model box 1 . In this embodiment, there are two water body range adjustment plates 7, and between the two water body range adjustment plates 7 is the water body distribution area. The top of the model material in the water body distribution area is waterproof with silica gel, and the water body range adjustment plate 7 top is connected to the model box 1. The top of the top is sealed and connected, the lower part is inserted into the model material, and the top of the model box 1 is sealed, so that the water body directly connected to the water body range adjustment plate 7 is guaranteed. Only when cracks occur on the top of the model material, the water will penetrate into the model material along the crack and accelerate the top. Water inrush damage. The two water body range adjustment plates 7 are model materials, the water pressure side measuring tube 8 is sealed and connected with the top plate of the model box 1, and the water pressure measuring tube 8 is fixed with the pressure measuring tube bracket 10, and the water pressure measuring tube 8 has a water pressure measuring tube. Pressure tube scale 9.

In a specific embodiment, according to the geological survey report of the Xinli Mining Area of the Sanshandao Gold Mine of Shandong Gold Group, considering the feasibility of the model test operation, the mechanical parameters in the following table 1 are used as the main mechanical parameters of different rocks designed for the model test after generalization .

Table 1 Main mechanical parameters of rocks in Xinli mining area of Sanshandao Gold Mine

group Bulk density/kg/m ³   Compressive strength/MPa Tensile strength/MPa Elastic modulus/GPa Poisson's ratio Cohesion/MPa Internal friction angle/degree Sericized granitic clastic rock 2706 71.26 6.24 13.44 0.20 11.44 30.6 Pyrite sericitized granitic clastic rock 2709 80.87 4.91 5.02 0.19 21.45 32.6 Granite 2635 102.95 8.54 17.1 0.24 42.77 36.94

Determine that the geometric similarity ratio is c _l =100, the size of the model box is 3000mm×1200mm×200mm, and the excavation position is in the middle of the model box. According to the actual mine size of about 20m×30m×50m, two methods of excavation are adopted. One is to excavate along the direction of the ore body according to the determined geometric similarity ratio model, which is 20cm in length×30cm in height; The mining height in the vertical direction of the ore body is 20cm x 50cm in length; as shown in Figure 9 and Figure 10. Determine that the gravity similarity ratio is c _g =1, the bulk density similarity ratio is c _ρ =1.5, then the stress similarity ratio is c _σ =c _g c _ρ c _l =150. The fixed time similarity ratio is c _t =365×24/(1/3)=26280, and the permeability coefficient similarity ratio is c _s =c _l /c _t =1/262.8.

According to the mechanical parameters of the original rock, the mechanical parameters of the model are shown in Table 2. According to experience, sand and paraffin are used as raw materials to make the model. The ratio of different groups is shown in Table 2.

Table 2 Main mechanical parameters and proportions of model design

group Bulk density/kg/m ³ Compressive strength/MPa Permeability coefficient/m/s Sand-high quality wax volume ratio Sericized granitic clastic rock 1804 0.475 2.18228E-07 0.3 Pyrite sericitized granitic clastic rock 1804 0.54 2.07109E-07 0.2 Granite 1757 0.686 1.88024E-07 0.15

The water pressure is arranged as shown in Figure 5 and Figure 6. The water pressure ranges from 0pa to 10Kpa, and the water pressure on the top is gradually increased until the roof is damaged by seepage and water inrush. It is realized by a side pressure control device, which includes a water body range adjustment plate 7, a water pressure piezometer 8, and a piezometer bracket 10;

The lateral pressure distribution is arranged in the form of Figure 7 and Figure 8, and the maximum lateral pressure is 800Kpa. It is realized by a side pressure control device, which includes a reaction force frame 4, a telescopic drive device 6, a control mechanism 11, and a high-pressure oil pressure pipeline 12;

Before the test begins, the digital camera and the digital camera tripod 18 as the first image acquisition device 17 are placed on the front position of the model box 1, and the CCD, stereo microscope 19, and stereo microscope as the second image acquisition device 20 The bracket 21 is placed directly behind the model box 1, the digital camera and CCD are connected to the computer 22, the instrument is adjusted, and the instrument is kept unchanged during the test.

During the test, different side pressures and top water pressure ranges and sizes were used to study the influence of side pressure and top water pressure on excavation. During the test, the displacement measurement device and the crack observation device were used to measure and analyze the displacement and cracks, so as to provide the necessary test criteria for the critical height of underwater mining.

The test simulates underwater mining using two methods of excavation as shown in Figure 9 and Figure 10;

1) Test results and analysis

Through the underwater mining roof seepage water inrush model test in Xinli mining area of Sanshandao Gold Mine of Shandong Gold Group, the following basic results can be obtained:

1. After the excavation of the model is completed, the maximum vertical displacement of the roadway appears in the middle and upper part of the roadway, and the stress analysis shows that the stress is concentrated at the corner. The uniform lateral pressure and the triangular lateral pressure distribution have different effects on the displacement, stress and displacement of the overburden of the excavated surrounding rock;

2. Two methods of excavation, inclined and horizontal, correspond to different distributions of surrounding rock displacement, and the displacement distribution of the overlying layer of the inclined mining method is different from that of horizontal excavation.

3. Increase the water head at the top of the model until the top plate is damaged, the two sides of the model and the model box are well sealed, and there is no artificial water inrush damage. With the increase of water pressure, the vertical displacement continues to increase, and cracks begin to appear. Finally Form a water inrush channel.

2) Test conclusion

Through the design of the test, the design of the model test device and test method, the preparation of similar materials, the production of the model, and the influence of different top water pressure and lateral pressure on the excavation of underwater mining, the results of seepage and water inrush damage in underwater mining are obtained. The whole process and rules, the basic conclusions are as follows:

1. The water inrush criterion for underwater mining should comprehensively consider structural stress, top water pressure, and changes in surface displacement and fractures.

2. Using the test device and method can provide a test basis for the critical mining height of underwater mining, and provide a criterion basis for engineering practice.

3. The model made by the present invention can simulate the effects of different lateral pressures and different water body distributions and sizes on seepage and water inrush damage in underwater mining.

4. Using stereo microscope, high-resolution digital camera and corresponding software can measure and analyze the distribution and size of cracks and displacement with sufficient precision, which provides advanced measurement technology for similar model test research and improves the accuracy and depth of measurement.

Claims (6)

1, a kind of offshore mining top board seepage flow sudden inflow test method the steps include:

(1) sets up model casing: utilize ratio of similitude to require configuration test model material, the test material that configures is positioned in the model casing according to actual relative position;

(2) apply lateral pressure: the cast material in the model casing is applied lateral pressure, and lateral pressure keeps constant in process of the test;

(3) apply water pressure: with the top seal of model casing, apply the water pressure of setting at the model top, be used for simulating the water pressure influence at marine mining top;

(4) model excavation: according to the test design requirement, carry out the model excavation, ore body excavation under the Simulated Water; In digging process, utilize the model surface displacement deformation measurement mechanism and the model surface gap observation device that are placed in positive front of model casing and positive back respectively, gather water pressure data, tectonic stress data, displacement digital photograph at regular intervals, amplify the crack digital photograph of certain multiple, gushing water destruction is taken place until excavating;

(5) repeating step (1), (2), (3) change lateral pressure, water pressure parameter, repeating step (4);

(6) the corresponding analysis software of utilization carries out Displacement Analysis and FRAC, obtains upper water pressure, the relation between tectonic stress and model surface displacement, the model surface crack.

2, a kind of offshore mining top board seepage flow sudden inflow test unit, it is characterized in that: it comprises the model casing (1) that is fixed on the pedestal (2), the lateral pressure applying mechanism, upper water pressure applying mechanism, control gear (11), model surface displacement deformation measuring mechanism, model surface gap observation mechanism and computing machine (22), described upper water pressure applying mechanism is positioned at the top of model casing (1), the lateral pressure applying mechanism is installed in two sides of model casing (1), and model surface displacement deformation measuring mechanism that links to each other with computing machine (22) and model surface gap observation mechanism are installed in the dead ahead and the dead astern of model casing (1) respectively.

3, offshore mining top board seepage flow sudden inflow test unit according to claim 2, it is characterized in that: described lateral pressure applying mechanism comprises the plural retractable driving device (6) that is positioned at model casing (1) both sides, retractable driving device (6) one ends link to each other with the movable side plate (5) that is positioned at model casing (1), the other end is by on reaction frame (4) fixed base (2), and retractable driving device (6) is by control gear (11) control.

4, according to claim 2 or 3 described offshore mining top board seepage flow sudden inflow test units, it is characterized in that: described model surface displacement deformation measuring mechanism comprises first image collecting device (17), model surface gap observation mechanism comprises second image collecting device (20) and microscope (19), described first image collecting device (17) and second image collecting device (20) lay respectively at the dead ahead and the dead astern of model casing (1), and first image collecting device (17) links to each other with computing machine (22) with second image collecting device (20).

5, according to claim 2 or 3 described offshore mining top board seepage flow sudden inflow test units, it is characterized in that: described water pressure applying mechanism comprises the hydraulic pressure piezometric tube (8) of being with scale and is used for regulating two blocks of water body range regulation plates (7) of model casing (1) top water body scope that hydraulic pressure piezometric tube (8) is inserted in the waters that forms between two blocks of water body range regulation plates (7).

6, offshore mining top board seepage flow sudden inflow test unit according to claim 4, it is characterized in that: described water pressure applying mechanism comprises the hydraulic pressure piezometric tube (8) of being with scale and is used for regulating two blocks of water body range regulation plates (7) of model casing (1) top water body scope that hydraulic pressure piezometric tube (8) is inserted in the waters that forms between two blocks of water body range regulation plates (7).

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