CN101487837B - Tester for changing soft rock expandability by electro-chemistry - Google Patents

Abstract

The invention provides a test device for electrochemically changing the expansibility of soft rock, which is characterized in that it includes a sample chamber, an electrolytic cell, a mesh isolation layer, a displacement sensor, an electrolytic cell top cover, an electrode, a power supply, a front-end device, and a data collector and output equipment; the outer side of the lower part of the cylindrical electrolytic cell has a liquid inlet, the liquid inlet is provided with a control valve, and the top cover of the electrolytic cell is installed on the upper part of the electrolytic cell; the test device is simple in structure, easy to operate, and automatically collects test data , accurate and fast, can test the expansion properties of soft rock under different electrolytes and electric fields, and form the expansion characteristic curves of soft rocks under different conditions. By comparing these curves, the differences in expansion properties of soft rocks under different electrolytes and electric fields can be obtained. It is used to interpret the inhibitory effect of electrochemical methods on the expansion of soft rocks, and provides basic test data for the engineering practice of electrochemical reinforcement of soft rocks. It can be widely used in mineral resource development and geotechnical engineering.

Description

Experimental device for electrochemically changing the expansibility of soft rock

technical field

The invention relates to a test device for electrochemical modification of soft rock, in particular to a test device for electrochemically changing the expansibility of soft rock.

Background technique

In the development of mineral resources and geotechnical engineering construction, a kind of unfavorable rock mass-soft rock is often encountered. This rock mass often contains a large amount of clay minerals, usually three groups of montmorillonite, illite and kaolinite. Among these three categories, the performance of montmorillonite group is the worst. It is a substance with extremely active physical and chemical properties, which is easy to absorb water and expand, and the expansion stress will make the roadways and chambers in this type of rock stratum Large deformation occurs; and after absorbing water, the strength of the rock decreases rapidly or even becomes muddy, which leads to instability and collapse of the rock mass, causing safety accidents and endangering personal safety.

At present, the commonly used approaches and methods for controlling the stability of soft rock engineering are mostly passive support and anchoring such as masonry and metal brackets, and for different geological conditions and environments, an anchoring and grouting support system with internal grouting bolts as the core has been developed. , combined anchorage system of threaded steel bolt-metal mesh-steel welded ladder beam-anchor cable-channel steel, etc., strong shell support system of soft rock roadway, reserved rigid-flexible layer control method and U-shaped steel support structure compensation technical control measures and other forms of support reinforcement. However, the above-mentioned support reinforcement method is only reinforced from the perspective of force balance, and does not solve the problem from the perspective of improving the mechanical properties and physical chemistry of the soft rock itself, and cannot effectively prevent the erosion of water on the soft rock. The soft rock engineering reinforced by the above method can only be maintained for a period of time, and needs to be repaired frequently, and the amount of repair and the expense are very large.

Invention patent (CN101319612A) discloses an electrochemical reinforcement method for soft rock. The basic principle is to apply a direct current electric field to the soft rock by artificial means, and under the action of the electric field, the charged ions inside the soft rock move directionally, so that the material of the soft rock The composition and structure are changed, the water swelling is reduced, the strength is increased, and irreversible curing occurs. However, due to unclear understanding of soft rock water-absorbing expansibility, electrochemical reinforcement effect, and parameters such as current, voltage, electrolyte, power-on timing and power-on time required in the actual construction process, the blindness of construction is caused, making this method in the field It is difficult to popularize and apply in engineering practice.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, to provide a method that can test the expansion performance of soft rock under different electrolytes and electric fields, form the expansion characteristic curve of soft rock under different conditions, and obtain different electrolytes by comparing these curves , The expansion difference of soft rock under the action of electric field is used to interpret the inhibition effect of electrochemical method on the expansion of soft rock, and provide basic experimental data for the engineering practice of electrochemical reinforcement of soft rock. Moreover, the device has simple structure, convenient operation, automatic collection of test data, accurate and fast electrochemical change of soft rock expansion test device.

Technical scheme of the present invention is:

The experimental device for electrochemically changing the expansibility of soft rock is characterized in that it includes a sample chamber, an electrolytic cell 1, a mesh isolation layer 4, a displacement sensor 8, an electrolytic cell top cover 9, an electrode 14, a power supply 15, a front device 16, Data collector 17 and output device 18; Described electrolyzer bottom outer side leaves liquid inlet 11, is provided with control valve 12 on the liquid inlet, and electrolyzer 9 top covers are contained in electrolyzer 1 top; Described sample chamber is composed of The porous plate 2 placed in the electrolytic cell 1, the porous piston 5, the sample loading ring 6 and the sample loading ring top cover 7 are composed of the porous plate 2 placed at the bottom of the rock sample 13, the outer edge of the porous plate and the sample loading ring 6 inner walls are in dynamic contact and sealing fit, the size of the porous piston 5 matches the size of the sample loading ring 6; Reticular isolation layers 4 are laid between them, and positive and negative electrodes 14 are respectively arranged at the contact parts between the reticular isolation layers 4 and the rock samples 13, and the positive and negative electrodes are respectively connected to the power supply 15 through wires; the porous piston is placed on the top of the rock samples, The piston rod passes through the hole of the top cover of the sample loading ring to contact the displacement sensor, and the displacement sensor is fixed on the top cover 9 of the electrolytic cell through the fixing bolt 10, and is connected to the front device 16 by a wire, and the front device 16 is connected to the electrolytic tank by a wire. Data collector 17 and output device 18.

The outstanding substantive features and remarkable effects of the present invention are: the device can determine the water-absorbing swelling property of soft rock, the effect of electrochemical modification and provide the required process parameters for the specific engineering practice of electrochemical reinforcement of soft rock, thereby It is possible to popularize and apply the electrochemical reinforcement method in soft rock engineering.

The invention has the advantages of simple structure, reliable performance, convenient operation, automatic collection of test data, accuracy and quickness, and wide practicability.

Description of drawings

Fig. 1 is a schematic structural diagram of the experimental device for electrochemically changing the expansibility of soft rock,

In the figure: electrolytic cell 1, porous plate 2, electrolyte solution 3, mesh isolation layer 4, porous piston 5, sample loading ring 6, sample loading ring top cover 7, displacement sensor 8, electrolytic cell top cover 9, fixing bolts 10 , liquid inlet 11, control valve 12, rock sample 13, electrode 14, power supply 15, front processor 16, data collector 17 and output device 18.

Detailed ways

As shown in Figure 1, the present invention electrochemically changes the expansibility test device of soft rock. It comprises sample chamber, electrolyzer 1, mesh isolation layer 4, displacement sensor 8, electrolyzer top cover 9, electrode 14, power supply 15, pre-processor 16, data collector 17 and output device 18; Described electrode is An inert electrode 14, a liquid inlet 11 is left outside the lower part of the electrolytic cell 1, and a control valve 12 is provided on the liquid inlet 11; the electrolytic cell top cover 9 is installed on the upper part of the electrolytic cell 1, and the sample chamber It consists of a porous plate 2 placed in the electrolytic cell 1, a porous piston 5, a sample loading ring 6 and a sample loading ring top cover 7. The porous plate is placed at the bottom of the rock sample, and the outer edge of the porous plate and the inner wall of the sample loading ring Intermittent dynamic contact and sealing fit, a mesh isolation layer is laid on the top of the porous plate, electrodes are arranged at the contact part between the mesh isolation layer and the rock sample 13, and the electrodes are connected to the power supply through wires; the porous piston 5 is placed on the top of the rock sample 13, and the piston The rod passes through the hole of the top cover of the sample loading ring to contact the displacement sensor, and the displacement sensor is fixed on the top cover of the electrolytic cell through the fixing bolt 10, and is connected to the front-end device by a wire, and the front-end device is connected to the data collector and the output device.

in:

The height of the electrolytic cell should be higher than the sample loading ring, and the liquid level of the electrolyte 3 should be higher than the top of the rock sample during the test.

The inner surface of the sample loading ring must be polished smooth, and the wall thickness is related to its external dimensions. In order to adapt to rock samples of various sizes, multiple sample loading rings of different sizes are configured.

The size of the porous plate and the porous piston matches the size of the sample loading ring, and they are made of high elastic modulus materials. The porous plate is in dynamic contact with the inner wall of the sample loading ring and is in sealing fit. The fit is just enough to ensure the free movement of the plate in the ring.

The output of the power supply is DC, with a voltage of 0-250V and a current of 0-120A, all of which are continuously adjustable.

Instructions for use of the experimental device for electrochemically changing soft rock expansibility of the present invention:

1. Insert the processed sample (or reshaped sample) 13 into the sample loading ring 6, and the rock sample must be tightly inserted into it.

2. Put the rock sample 13 and the sample loading ring 6 on the circular porous plate 2 laid with the mesh isolation layer 4, install the electrode 14 at the contact part between the mesh isolation layer 4 and the rock sample 13, insert the porous piston 5, adjust The porous plate 2, the rock sample 13 and the porous piston 5 make the three closely connected, cover the top cover 7 of the sample loading ring, and then move it into the electrolytic cell 1, adjust the sample chamber and make the piston rod fixed in the electrolytic cell The displacement sensor 8 on the top cover 9 is connected and centered, and the displacement sensor 8 is connected with the front processor 16, the data collector 17 and the output device 18.

3. Connect the upper and lower electrodes 14 of the rock sample 13 to the negative pole and the positive pole of the power supply respectively, and record the initial reading of the displacement sensor 8 .

4. Turn on the power supply 15, inject the electrolyte 3 into the electrolytic cell 1 until the liquid level is higher than the top of the rock sample 13, at this time, the rock sample 13 begins to expand, and the output voltage of the displacement sensor 8 changes, and the change is passed through the pre-amplifier 16 is passed to the data collector 17 for analog-to-digital conversion, and the process of the expansion of the rock sample 13 with time is recorded online by the computer, and the test parameters and the variation curve of the expansion with time are printed out in the form of a table through the output device 18 .

5. According to the setting plan, adjust the output current and voltage of the power supply 15, replace the electrolyte 3, conduct expansion tests of different electrolyte types, concentrations, voltages, currents, power-on timing and power-on time, compare the test results, and give a soft rock Based on the effect of electrochemical modification, the optimal process parameters of electrochemical strengthening of soft rock are obtained.

According to the above description, any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention.

Claims (3)

1. A test device for electrochemically changing the expansibility of soft rock, characterized in that it comprises a sample chamber, an electrolytic cell (1), a mesh isolation layer (4), a displacement sensor (8), and an electrolytic cell top cover (9) , electrode (14), power supply (15), front-end device (16), data collector (17) and output device (18); Described electrolyzer bottom outer side leaves liquid inlet (11), on the liquid inlet A control valve (12) is provided, and the top cover of the electrolytic cell (9) is installed on the top of the electrolytic cell (1); the sample chamber is composed of a porous plate (2) placed in the electrolytic cell (1), a porous piston (5) 1. The sample loading ring (6) is composed of the sample loading ring top cover (7), the porous plate (2) is placed at the bottom of the rock sample (13), between the outer edge of the porous plate and the inner wall of the sample loading ring (6) The size of the porous piston (5) matches the size of the sample loading ring (6); the top of the porous plate (2) is in contact with the rock sample (13) and the hole of the porous piston (5). Between the bottom and the rock sample (13), a mesh isolation layer (4) is respectively laid, and positive and negative electrodes (14) are respectively arranged at the contact parts of the mesh isolation layer (4) and the rock sample (13), and the positive and negative electrodes respectively pass through the The wire is connected to the power supply (15); the porous piston is placed on the top of the rock sample, and the piston rod passes through the hole in the top cover of the sample loading ring to contact the displacement sensor, and the displacement sensor is fixed in the electrolytic cell by a fixing bolt (10). On the top cover (9), the front-end device (16) is connected by wires, and the front-end device (16) is connected to the data collector (17) and the output device (18) by wires. 2. The experimental device for electrochemically changing the expansibility of soft rock according to claim 1, characterized in that: the height of the electrolytic cell (1) should be higher than the sample loading ring (6), and the electrolyte (3) The liquid level should be higher than the rock sample (13) top. 3. The test device for electrochemically changing the expansibility of soft rock according to claim 1, characterized in that: said sample loading ring (6) is configured with several different-sized rock samples (13) according to different sizes. Sample ring (6).

Images