A kind of simulated crack test device and test method

Abstract

The present invention discloses a simulated fissure test device and test method, which relates to the technical field of long-term safety performance test of buffer / backfill materials for geological disposal of high-level radioactive waste, and comprises a liquid supply bottle, a peristaltic pump, a degassing mechanism, a simulated fissure mechanism and a collector which are connected in sequence, the liquid supply bottle contains liquid, the simulated fissure mechanism comprises an upper mold and a lower mold which are interlocked, the gap between the upper mold and the lower mold is a simulated fissure, a sample bin is arranged at the center of the upper mold and the lower mold, the sample bin contains samples, and the simulation of fissures with different openings is realized by changing the height of the simulated gap between the upper mold and the lower mold. The present invention explores the expansion changes of bentonite, a buffer / backfill material, the law of outward movement of particulate matter, the turbidity of the outflowing liquid, the changes in conductivity and the volume value of the liquid, which is of great importance for studying the long-term stability of buffer / backfill materials for geological disposal of high-level radioactive waste.

Description

Technical Field

[0001] The invention relates to the technical field of long-term safety performance test of buffer / backfill materials for geological disposal of high-level radioactive waste, and in particular to a buffer / backfill material simulated crack test device and test method. Background Art

[0002] High-level radioactive waste, referred to as high-level waste, contains a large amount of highly toxic and long-half-life radionuclides, releases a large amount of heat, and poses a high environmental risk. It requires a high degree of containment and isolation measures to protect people and the environment from its harm. How to achieve the safe disposal of high-level waste is a global problem. At present, deep geological disposal is considered to be a reasonable and feasible high-level waste disposal solution, and nuclear-weaponized countries around the world have carried out a lot of research on this. The goal of deep geological disposal is to achieve the final safe disposal of high-level waste by building a high-level waste disposal repository in a stable geological body 500 to 1000 meters deep from the surface, so as to permanently isolate it from the human living environment. High-level waste disposal repositories generally adopt the design concept of "multiple barriers", in which waste bodies, packaging containers and buffer / backfill materials are called "engineered barriers", and the surrounding rocks of the disposal repository are called "natural barriers".

[0003] Groundwater is the carrier of high-level radioactive waste leakage to the external space of the disposal repository. Buffer / backfill materials, as the last artificial barrier filled between the waste tank and the geological body, play an important role as a hydraulic barrier, preventing groundwater (which may contain corrosive substances) from flowing to the surface of the waste tank, and preventing water-soluble compounds and nuclides in the waste tank from leaking into the surrounding rock. Therefore, it is necessary to master the interface between the buffer / backfill materials (mainly bentonite) and the fractured rock mass, the expansion changes caused by groundwater of different chemical compositions and different flow rates, the outward movement of clay particles, and the changes in turbidity and conductivity of the outflowing liquid.

[0004] The simulated crack test of bentonite, a buffer / backfill material, at the soil-rock interface requires comparison of cracks with different openings and inclinations, and the study of the relationship between the chemical composition and flow rate of groundwater, the composition and density of bentonite and expansion deformation, the law of outward movement of particulate matter, the turbidity of the outflowing liquid, the change of conductivity, etc. However, the existing technology cannot study so many influencing factors at the same time. Summary of the invention

[0005] The purpose of the present invention is to provide a simulated crack test device and test method to solve the problems existing in the above-mentioned prior art, and to explore the expansion changes of buffer / backfill materials, the outward movement rules of particulate matter and the turbidity and conductivity changes of the outflowing liquid and the volume value of the liquid when different liquids and different flow rates flow through simulated cracks with different openings.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a simulated crack test device, comprising a liquid supply bottle, a peristaltic pump, a degassing mechanism, a simulated crack mechanism and a collector which are connected in sequence, the liquid supply bottle is used to hold liquid, the simulated crack mechanism comprises an upper mold and a lower mold which are interlocked, the gap between the upper mold and the lower mold is a simulated crack, a sample bin is arranged at the center position of the upper mold and the lower mold, the sample bin is used to hold samples, and the simulation of cracks with different openings can be achieved by changing the height of the simulated gap between the upper mold and the lower mold.

[0008] Preferably, a first liquid inlet pipe is provided on one side of the simulated fissure mechanism, and a first liquid outlet pipe is provided on the other side of the simulated fissure mechanism, the first liquid inlet pipe and the first liquid outlet pipe are both connected to the simulated fissure, the degassing mechanism is connected to the first liquid inlet pipe through a pipeline, and the collector is connected to the first liquid outlet pipe.

[0009] Preferably, a first sealing ring is arranged between the upper mold and the lower mold, the liquid inlet of the first liquid inlet pipe and the liquid outlet of the first liquid outlet pipe are located on the inner side of the first sealing ring, the first sealing ring is arranged in a groove close to the edge of the upper mold and the lower mold, the upper mold and the lower mold are connected by a plurality of first bolts, and the plurality of first bolts are located on the outer side of the first sealing ring, and a plurality of support seats are arranged at the bottom of the lower mold.

[0010] Preferably, the degassing mechanism includes a liquid storage column, an upper cover is provided at the upper end of the liquid storage column, an exhaust hole is opened on the upper cover, a base is provided at the lower end of the liquid storage column, a second sealing ring is provided between the liquid storage column, the upper cover and the base, the upper cover and the base are fixed by a plurality of second bolts, a second liquid inlet pipe passes through the upper cover and is connected to the liquid storage column, the second liquid inlet pipe of the degassing mechanism is connected to the liquid outlet end of the peristaltic pump, the second liquid outlet pipe passes through the base and is connected to the liquid storage column, and the second liquid outlet pipe is connected to the first liquid inlet pipe.

[0011] Preferably, the upper mold and the lower mold are both made of organic glass, and at least one scale bar is provided on the upper mold, and the reading of the scale bar gradually increases from the center of the sample chamber to the edge of the upper mold.

[0012] Preferably, a camera is provided above the upper mold.

[0013] The present invention also provides a simulated crack test method using the simulated crack test device, comprising the following steps:

[0014] S1: Assemble the simulated crack mechanism and conduct a sealing test on the simulated crack mechanism;

[0015] S2: placing the sample into the sample chamber of the simulated crack mechanism, connecting the remaining structures of the simulated crack test device, and degassing the simulated crack test device;

[0016] S3: Data collection: Turn on the peristaltic pump, the liquid in the liquid supply bottle corrodes the sample, the collector collects the corroded liquid and measures its turbidity, conductivity and volume, and the camera takes pictures of the expansion deformation and corrosion of the sample;

[0017] S4: Dismantle the device and perform sample processing.

[0018] Preferably, in S2, degassing the simulated crack test device comprises the following steps:

[0019] a1: Use an ultrasonic cleaner to degas the liquid, and then pour the degassed liquid into the liquid supply bottle;

[0020] a2: connect the liquid inlet of the peristaltic pump to the liquid supply bottle, connect the liquid outlet of the peristaltic pump to the second liquid inlet pipe of the degassing mechanism, connect the second liquid outlet pipe of the degassing mechanism to the first liquid inlet pipe of the simulated slit mechanism, and clamp the pipeline between the second liquid outlet pipe and the first liquid inlet pipe with a clamp;

[0021] a3: Unscrew the exhaust hole of the degassing mechanism, and introduce liquid into the liquid storage column of the degassing mechanism. After the liquid is filled, stop the peristaltic pump and tighten the exhaust hole;

[0022] a4: Loosen the pipe clamping part between the second liquid outlet pipe and the first liquid inlet pipe;

[0023] a5: Raise the first liquid outlet pipe end of the simulated fracture mechanism;

[0024] a6: Clamp the first liquid outlet tube with a clamp and place the end of the first liquid outlet tube in an empty liquid collecting bottle;

[0025] a7: Turn on the peristaltic pump to pass the liquid into the simulated slit mechanism. When the liquid overflows from the first sealing ring gap at the first liquid outlet pipe end of the simulated slit mechanism, stop the peristaltic pump and tighten the first bolt;

[0026] a8: Take out the first liquid outlet pipe from the liquid collecting bottle and connect it to the collector, then open the clamp on the first liquid outlet pipe to complete the degassing of the simulated crack test device.

[0027] Preferably, in S3, data collection includes the following steps:

[0028] b1: Set the flow rate of the peristaltic pump and record it;

[0029] b2: From the time the peristaltic pump quantitatively supplies liquid, take photos every 5 minutes for 24 hours, take the outflowing liquid from the collector every hour, measure its turbidity, conductivity and volume, and collect all the outflowing liquid from the collector every day, pour it into the liquid collection bottle, and dry it all;

[0030] b3: From the time the peristaltic pump quantitatively supplies liquid, take photos every half an hour for 24 to 48 hours, and collect the outflowing liquid every 3 hours to measure its turbidity, conductivity and volume;

[0031] b4: From the time when the peristaltic pump quantitatively supplies the liquid, after 48 hours, take photos every 5 hours, take the outflowing liquid every 5 hours, and measure its turbidity, conductivity and volume. When the turbidity value of the outflowing liquid drops to the range of 0-10NTU, take the outflowing liquid every 50 hours, and measure its turbidity, conductivity and volume. When the turbidity value of the outflowing liquid drops to the range of 0-1NTU, take the outflowing liquid every 200 hours, and measure its turbidity, conductivity and volume. After one week or when the sample expansion change is not obvious within 24 hours, take photos every day;

[0032] b5: until the sample has no obvious expansion change within 72 hours, take photos every 3 days;

[0033] b6: Stop the peristaltic pump until the sample expands for one week and the turbidity of the collected liquid is between 0 and 1 NTU;

[0034] b7: Take out the liquid inlet end of the peristaltic pump from the liquid supply bottle, connect the liquid outlet end of the peristaltic pump to the first liquid inlet tube, let in air and drain water, and control the air intake rate at 0.1~0.5ml / min. After drainage is completed, use clamps to clamp the first liquid inlet tube and the first liquid outlet tube that simulate the slit mechanism.

[0035] Preferably, in S4, the sample processing comprises the following steps:

[0036] c1: Place the simulated crack mechanism in a refrigerator and quickly freeze it at -20°C, then quickly separate the lower mold from the upper mold, collect and weigh samples in circles according to the observed outward movement range of the material;

[0037] c2: freeze-dry the samples collected in each circle, weigh them after drying, obtain the dry weight of each circle of samples, and calculate the moisture content;

[0038] c3: Detect the material composition of each circle of samples, and summarize the moisture content of each circle of samples and the law of material movement outward;

[0039] c4: Compare the weight of the dried material in the collected outflow liquid, the dry weight of the remaining material in the sample chamber, and the dry weight of the material in other structures in the simulated crack test device, evaluate the crack sealing and erosion resistance of the buffer / backfill material bentonite, and study the relationship between expansion deformation, whether erosion occurs and the amount of erosion and the sample composition, dry density, composition of the inflowing liquid, flow rate, crack opening and inclination.

[0040] Compared with the prior art, the present invention has achieved the following technical effects:

[0041] The present invention studies the expansion changes caused by different liquids eroding samples, the law of outward movement of particulate matter, and collects the turbidity, conductivity change and liquid volume change data of the outflowing liquid by changing the chemical composition of the liquid contained in the liquid supply bottle, realizes the simulation of cracks with different openings by changing the distance between the upper and lower plates of the crack device, realizes the simulation of cracks with different inclination angles by setting the angle between the crack device and the horizontal plane, and studies the expansion changes caused by liquid eroding samples at different flow rates, the law of outward movement of matter, and collects the turbidity, conductivity change and liquid volume change data of the outflowing liquid by changing the flow rate of the peristaltic pump. The present invention is of great importance to the long-term stability research of high-level waste disposal buffer / backfill materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 This is a schematic diagram of the erosion of the sample under the action of the liquid penetrating the simulated fracture;

[0044] Figure 2 It is a schematic diagram of the simulated crack test device of the present invention;

[0045] Figure 3 It is a schematic diagram of the upper mold in the present invention;

[0046] Figure 4 It is a schematic diagram of the lower mold in the present invention;

[0047] Figure 5 It is a schematic diagram of the degassing mechanism in the present invention;

[0048] Figure 6 A schematic diagram of the camera and the simulated crack mechanism in the present invention;

[0049] Figure 7 It is a schematic diagram of the liquid collecting bottle and the simulated crack mechanism in the present invention;

[0050] Figure 8 It is a schematic diagram of the simulated crack test process in the present invention;

[0051] Wherein: 100-simulated crack test device, 1-first liquid inlet pipe, 2-lower mold, 3-threaded hole, 4-support seat, 5-first sealing ring, 6-sample chamber, 7-simulated crack, 8-first liquid outlet pipe, 9-scale bar, 10-upper mold, 11-liquid supply bottle, 12-peristaltic pump, 13-degassing mechanism, 14-collector, 15-camera, 16 exhaust hole, 17-upper cover, 18-base, 19-liquid storage column, 20-second sealing ring, 21-second bolt, 22-second liquid inlet pipe, 23-second liquid outlet pipe, 24-simulated crack mechanism, 25-sample, 26-liquid collecting bottle. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] The purpose of the present invention is to provide a simulated crack test device and test method to solve the problems existing in the above-mentioned prior art, and to explore the expansion changes and outward movement rules of the buffer / backfill material bentonite when different liquids and different flow rates flow through simulated cracks with different openings, as well as the changes in turbidity and conductivity of the outflowing liquid and the volume value of the liquid.

[0054] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0055] like Figure 1-Figure 8As shown: This embodiment provides a simulated crack test device 100, comprising a liquid supply bottle 11, a peristaltic pump 12, a degassing mechanism 13, a simulated crack mechanism 24 and a collector 14 connected in sequence, the collector 14 is an automatic collector, the liquid supply bottle 11 is used to hold liquid, the simulated crack mechanism 24 comprises an upper mold 10 and a lower mold 2 that are interlocked, the gap between the upper mold 10 and the lower mold 2 is a simulated crack 7, the lower mold 2 has a groove of a certain depth, and a sample chamber 6 is provided at the center of the upper mold 10 and the lower mold 2, the sample chamber 6 is used to hold a sample 25, and the simulation of cracks with different openings is achieved by changing the height of the simulated gap 7 between the upper mold 10 and the lower mold 2, that is, the simulation of cracks with different openings is achieved by changing the depth of the groove in the lower mold 2 (that is, the distance between the upper mold 10 and the lower mold 2). In this embodiment, the expansion change values, outward movement rules of substances produced by different liquids eroding the sample 25 are studied by changing the liquid contained in the liquid supply bottle 11, and the turbidity, conductivity change and liquid volume change data of the outflowing liquid are collected. The simulation of cracks with different openings is achieved by changing the depth of the groove in the lower mold 2. The expansion change values, outward movement rules of substances produced by liquids eroding the sample 25 at different flow rates, and the turbidity, conductivity change and liquid volume change data of the outflowing liquid are studied by changing the flow rate of the peristaltic pump 12. This embodiment is of great importance for studying the long-term stability of high-level radioactive waste geological disposal buffer / backfill materials.

[0056] Specifically, in this embodiment, a first liquid inlet pipe 1 is provided on one side of the simulated crack mechanism 24, and a first liquid outlet pipe 8 is provided on the other side of the simulated crack mechanism 24. The first liquid inlet pipe 1 and the first liquid outlet pipe 8 are arranged opposite to each other. The first liquid inlet pipe 1 and the first liquid outlet pipe 8 are both composed of a plurality of branch pipes, and the plurality of branch pipes are evenly arranged. The first liquid inlet pipe 1 and the first liquid outlet pipe 8 are both connected to the simulated crack 7, the degassing mechanism 13 is connected to the first liquid inlet pipe 1 through a pipeline, and the collector 14 is connected to the first liquid outlet pipe 8.

[0057] In this embodiment, a first sealing ring 5 is arranged between the upper mold 10 and the lower mold 2, the liquid inlet of the first liquid inlet pipe 1 and the liquid outlet of the first liquid outlet pipe 8 are located on the inner side of the first sealing ring 5, the first sealing ring 5 is arranged in a groove close to the edge of the upper mold 10 and the lower mold 2, the upper mold 10 and the lower mold 2 are connected by a plurality of first bolts, and the plurality of first bolts are located on the outer side of the first sealing ring 5, and a plurality of support seats 4 are arranged at the bottom of the lower mold 2, and the height of the support seats 4 can be adjusted.

[0058] In this embodiment, the degassing mechanism 13 includes a liquid storage column 19, an upper cover 17 is provided at the upper end of the liquid storage column 19, an exhaust hole 16 is opened on the upper cover 17, a base 18 is provided at the lower end of the liquid storage column 19, a second sealing ring 20 is provided between the liquid storage column 19, the upper cover 17 and the base 18, the upper cover 17 and the base 18 are fixed by a plurality of second bolts 21, a second liquid inlet pipe 22 passes through the upper cover 17 and is connected to the liquid storage column 19, the second liquid inlet pipe 22 of the degassing mechanism 13 is connected to the liquid outlet end of the peristaltic pump 12, the second liquid outlet pipe 23 passes through the base 18 and is connected to the liquid storage column 19, and the second liquid outlet pipe 23 is connected to the first liquid inlet pipe 1.

[0059] In this embodiment, the upper mold 10 and the lower mold 2 are both made of organic glass, which is resistant to acid and alkali and does not react with chemical reagents, and has high transparency. At least one scale bar 9 is provided on the upper mold 10, and the reading of the scale bar 9 gradually increases from the center of the sample chamber 6 to the edge of the upper mold 10. In this embodiment, four scale bars 9 are provided, and the four scale bars 9 are arranged at intervals of 90°.

[0060] In this embodiment, a camera 15 is disposed above the upper mold 10, and the camera 15 is used to take pictures of the expansion deformation and erosion of the sample 25. Figure 8 As shown, the circular pattern at the simulated crack 7 is a trace formed by the sample 25 moving outward after being eroded by the liquid. The camera 15 captures the pattern of the sample 25 moving outward after being eroded by different liquids and different flow rates.

[0061] This embodiment changes the liquid contained in the liquid supply bottle 11 to achieve the expansion change of the sample 25 and the law of outward movement of the substance, the change of turbidity and conductivity of the outflowing liquid, and the volume value of the liquid when different liquids flow through the simulated cracks 7 with different openings; changes the flow rate of the peristaltic pump 12 to achieve the expansion change of the sample 25 and the law of outward movement of the substance, the change of turbidity and conductivity of the outflowing liquid, and the volume value of the liquid when different flow rates flow through the simulated cracks 7 with different openings; the depth of the groove in the lower mold 2 is changed to achieve the simulated cracks 7 with different openings. This embodiment can also add other substances to the sample 25 before pressing the sample 25. This embodiment can also study the relationship between different crack inclination angles and the expansion change of the sample 25 and the law of outward movement of the substance, the change of turbidity and conductivity of the outflowing liquid, and the volume value of the liquid by changing the angle between the simulated crack mechanism 24 and the horizontal plane. Example

[0062] This embodiment provides a simulated crack test method using the simulated crack test device 100 of the first embodiment, comprising the following steps:

[0063] Before the test, the crack opening is first detected. The crack parts of the lower mold 2 and the upper mold 10 are first coated with a developer, and then scanned with a three-dimensional scanner to measure the crack opening. The crack opening error range is ±5‰ of 1mm;

[0064] S1: Assembling the simulated crack mechanism 24 and performing a sealing test on the simulated crack mechanism 24;

[0065] The sealing test includes the following steps:

[0066] d1: Place the first sealing ring 5 into the groove of the lower mold 2;

[0067] d2: Put the first bolt into the threaded hole 3, tighten the lower mold 2 and the upper mold 10, and install the support seat 4;

[0068] d3: the liquid inlet end of the peristaltic pump 12 is connected to the liquid supply bottle 11, the liquid outlet end of the peristaltic pump 12 is connected to the first liquid inlet pipe 1, and the first liquid outlet pipe 8 is connected to the liquid collection bottle 26;

[0069] d4: Set the flow rate of the peristaltic pump 12 and observe whether there is water leakage from the first sealing ring 5;

[0070] d5: After the sealing water test is completed, if the sealing is good, drain the water first, then disassemble the upper mold 10 and the lower mold 2 and blow dry;

[0071] d6: If the sealing is not good, reseal it and then conduct a sealing water test until the sealing is good;

[0072] S2: Record information such as the sample 25, liquid, upper mold 10 and lower mold 2, place the lower mold 2 on a horizontal platform, adjust the support seat 4 to make the lower mold 2 in a horizontal state, put the sample 25 into the sample chamber 6 of the lower mold 2, and then align the sample chamber 6 of the upper mold 10 with the sample 25, and slowly lower it in a horizontal state; connect the remaining structures of the simulated crack test device 100, put the first bolt into the threaded hole 3, fix the lower mold 2 and the upper mold 10, tighten the first bolt symmetrically, and except for the end close to the first liquid inlet pipe 1 that is directly tightened to the tightest state, reserve certain gaps on the other three sides, and then degas the simulated crack test device 100;

[0073] In S2, degassing the simulated crack test device 100 includes the following steps:

[0074] a1: Degas the liquid using an ultrasonic cleaner, and then pour the degassed liquid into the liquid supply bottle 11;

[0075] a2: connect the liquid inlet end of the peristaltic pump 12 to the liquid supply bottle 11, connect the liquid outlet end of the peristaltic pump 12 to the second liquid inlet pipe 22 of the degassing mechanism 13, connect the second liquid outlet pipe 23 of the degassing mechanism 13 to the first liquid inlet pipe 1 of the simulated slit mechanism 24, and clamp the pipeline between the second liquid outlet pipe 23 and the first liquid inlet pipe 1 with a clamp;

[0076] a3: Unscrew the exhaust hole 16 of the degassing mechanism 13, and introduce liquid into the liquid storage column 19 of the degassing mechanism 13. After the liquid is filled, stop the peristaltic pump 12 and tighten the exhaust hole 16;

[0077] a4: loosen the pipe clamping portion between the second liquid outlet pipe 23 and the first liquid inlet pipe 1;

[0078] a5: Raise the end of the first liquid outlet pipe 8 of the simulated crack mechanism 24;

[0079] a6: Clamp the first liquid outlet pipe 8 with a clamp, and place the end of the first liquid outlet pipe 8 in an empty liquid collecting bottle 26;

[0080] a7: Turn on the peristaltic pump 12 to pass the liquid into the simulated slit mechanism 24. When the liquid overflows from the gap of the first sealing ring 5 at the end of the first liquid outlet pipe 8 of the simulated slit mechanism 24, stop the peristaltic pump 12 and tighten all the first bolts;

[0081] a8: Take out the first liquid outlet pipe 8 from the liquid collecting bottle 26 and connect it to the collector 14, then open the clamp on the first liquid outlet pipe 8 to complete the degassing of the simulated crack test device 100.

[0082] S3: Data collection: The peristaltic pump 12 is turned on, and the liquid in the liquid supply bottle 11 corrodes the sample 25. The collector 14 collects the corroded liquid and measures its turbidity, conductivity and volume. The camera 15 takes pictures of the expansion deformation and corrosion of the sample 25.

[0083] In S3, data collection includes the following steps:

[0084] b1: setting the flow rate of the peristaltic pump 12 and recording it;

[0085] b2: From the time when the peristaltic pump 12 quantitatively supplies liquid, take a picture every 5 minutes for 24 hours, take the outflowing liquid from the collector 14 once every hour, measure its turbidity, conductivity and volume, and collect all the outflowing liquid from the collector 14 every day and pour it into the liquid collection bottle 26, and dry it all;

[0086] b3: From the time when the peristaltic pump 12 quantitatively supplies the liquid, take a picture every half an hour for 24 to 48 hours, and take the outflowing liquid from the collector 14 every 3 hours to measure its turbidity, conductivity and volume;

[0087] b4: From the time when the peristaltic pump 12 quantitatively supplies the liquid, after 48 hours, take photos every 5 hours, take the outflowing liquid every 5 hours, and measure its turbidity, conductivity and volume. When the turbidity value of the outflowing liquid drops to the range of 0-10NTU (NTU is turbidity), take the outflowing liquid every 50 hours to measure its turbidity, conductivity and volume. When the turbidity value of the outflowing liquid drops to the range of 0-1NTU, take the outflowing liquid every 200 hours to measure its turbidity, conductivity and volume. After one week or when the expansion change of the sample 25 is not obvious within 24 hours, take photos every day.

[0088] b5: until the sample has no obvious expansion change within 25 to 72 hours, take photos every 3 days;

[0089] b6: until the expansion change of the sample 25 is not obvious within one week and the turbidity of the collected liquid is between 0 and 1 NTU, the peristaltic pump 12 is stopped;

[0090] b7: Take out the liquid inlet end of the peristaltic pump 12 from the liquid supply bottle 11, connect the liquid outlet end of the peristaltic pump 12 to the first liquid inlet tube 1, and drain water with the air intake rate controlled at 0.1~0.5ml / min. After drainage is completed, clamp the first liquid inlet tube 1 and the first liquid outlet tube 8 of the simulated slit mechanism 24 with a clamp.

[0091] The photos taken every day, the turbidity, conductivity and volume of the collected liquid measured, etc. are processed in time. The photo readings are read in the order of inner circle, middle circle and outer circle. The circle division principle is based on color, the innermost circle is black, the middle circle is yellow, and the outermost circle is white. The reading value should be accurate to 1mm, and then the readings of the four sides of each circle are added and the average value is taken as the value of this circle. Observe the expansion of sample 25, the law of material movement outward, and the changes in the turbidity and conductivity of the collected liquid.

[0092] S4: Dismantle the device and process sample 25.

[0093] In S4, the sample 25 processing includes the following steps:

[0094] c1: Put the simulated crack structure 24 into a refrigerator and quickly freeze it at -20°C, then quickly separate the lower mold 2 from the upper mold 10, and collect and weigh the samples 25 in circles according to the observed outward movement range of the substance;

[0095] c2: freeze-dry the samples 25 collected in different circles. The container for holding the samples 25 used for freeze-drying is made of polytetrafluoroethylene. Freeze-drying requires liquid nitrogen or a -80°C ultra-low temperature refrigerator. The container must be resistant to low temperatures. Freeze-drying requires vacuuming. The container must be pressure-resistant. The partitions in the container are also made of polytetrafluoroethylene and are firmly fixed. The freeze-drying time is set to more than 48 hours. After drying, weigh the sample 25 in each circle to obtain the dry weight and calculate the moisture content.

[0096] c3: Detect the material composition of each circle of sample 25, and summarize the moisture content of each circle of sample 25 and the law of material movement outward;

[0097] c4: Compare the weight of the dried material in the collected outflowing liquid, the dry weight of the remaining material in the sample bin 6, and the dry weight of the material in other structures in the simulated crack test device 100, evaluate the crack sealing and erosion resistance of the buffer / backfill material bentonite, and study the relationship between expansion deformation, whether erosion occurs and the amount of erosion and the composition of the sample 25, dry density, composition of the inflowing liquid, flow rate, crack opening, inclination, etc.

[0098] The present specification uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A simulated crack test device, characterized in that: The invention comprises a liquid supply bottle, a peristaltic pump, a degassing mechanism, a simulated crack mechanism and a collector which are connected in sequence, wherein the liquid supply bottle is used to hold liquid, the simulated crack mechanism comprises an upper mold and a lower mold which are interlocked, the gap between the upper mold and the lower mold is a simulated crack, a sample bin is arranged at the center of the upper mold and the lower mold, the sample bin is used to hold samples, and the simulation of cracks with different openings is achieved by changing the height of the simulated gap between the upper mold and the lower mold; A first liquid inlet pipe is provided on one side of the simulated slit mechanism, and a first liquid outlet pipe is provided on the other side of the simulated slit mechanism, the first liquid inlet pipe and the first liquid outlet pipe are both connected to the simulated slit, the degassing mechanism is connected to the first liquid inlet pipe through a pipeline, and the collector is connected to the first liquid outlet pipe; The degassing mechanism comprises a liquid storage column, an upper cover is provided at the upper end of the liquid storage column, an exhaust hole is provided on the upper cover, a base is provided at the lower end of the liquid storage column, a second sealing ring is provided between the liquid storage column, the upper cover and the base, the upper cover and the base are fixed by a plurality of second bolts, a second liquid inlet pipe passes through the upper cover and is communicated with the liquid storage column, a second liquid inlet pipe of the degassing mechanism is communicated with the liquid outlet end of the peristaltic pump, a second liquid outlet pipe passes through the base and is communicated with the liquid storage column, and the second liquid outlet pipe is communicated with the first liquid inlet pipe; A camera is arranged above the upper mold.

2. The simulated crack test device according to claim 1, characterized in that: A first sealing ring is arranged between the upper mold and the lower mold, the liquid inlet of the first liquid inlet pipe and the liquid outlet of the first liquid outlet pipe are located on the inner side of the first sealing ring, the first sealing ring is arranged in a groove close to the edge of the upper mold and the lower mold, the upper mold and the lower mold are connected by a plurality of first bolts, and the plurality of first bolts are located on the outer side of the first sealing ring, and a plurality of support seats are arranged at the bottom of the lower mold.

3. The simulated crack test device according to claim 1, characterized in that: The upper mold and the lower mold are both made of organic glass. The upper mold is provided with at least one scale bar, and the reading of the scale bar increases gradually from the center of the sample chamber to the edge of the upper mold.

4. A simulated crack test method using the simulated crack test device according to any one of claims 1 to 3, characterized in that: The steps include: S1: Assemble the simulated crack mechanism and conduct a sealing test on the simulated crack mechanism; S2: placing the sample into the sample chamber of the simulated crack mechanism, connecting the remaining structures of the simulated crack test device, and degassing the simulated crack test device; S3: Data collection: Turn on the peristaltic pump, the liquid in the liquid supply bottle corrodes the sample, the collector collects the corroded liquid and measures its turbidity, conductivity and volume, and the camera takes pictures of the expansion deformation and corrosion of the sample; S4: Dismantle the device and perform sample processing.

5. The simulated crack test method according to claim 4, characterized in that: In S2, degassing the simulated crack test device comprises the following steps: a1: Use an ultrasonic cleaner to degas the liquid, and then pour the degassed liquid into the liquid supply bottle; a2: connect the liquid inlet of the peristaltic pump to the liquid supply bottle, connect the liquid outlet of the peristaltic pump to the second liquid inlet pipe of the degassing mechanism, connect the second liquid outlet pipe of the degassing mechanism to the first liquid inlet pipe of the simulated slit mechanism, and clamp the pipeline between the second liquid outlet pipe and the first liquid inlet pipe with a clamp; a3: Unscrew the exhaust hole of the degassing mechanism, and introduce liquid into the liquid storage column of the degassing mechanism. After the liquid is filled, stop the peristaltic pump and tighten the exhaust hole; a4: Loosen the pipe clamping part between the second liquid outlet pipe and the first liquid inlet pipe; a5: Raise the first liquid outlet pipe end of the simulated fracture mechanism; a6: Clamp the first liquid outlet tube with a clamp and place the end of the first liquid outlet tube in an empty liquid collection bottle; a7: Turn on the peristaltic pump to pass the liquid into the simulated slit mechanism. When the liquid overflows from the first sealing ring gap at the first liquid outlet pipe end of the simulated slit mechanism, stop the peristaltic pump and tighten the first bolt; a8: Take out the first liquid outlet pipe from the liquid collecting bottle and connect it to the collector, then open the clamp on the first liquid outlet pipe to complete the degassing of the simulated crack test device.

6. The simulated crack test method according to claim 4, characterized in that: In S3, data collection includes the following steps: b1: Set the flow rate of the peristaltic pump and record it; b2: From the time the peristaltic pump quantitatively supplies liquid, take photos every 5 minutes for 24 hours, take the outflowing liquid from the collector every hour, measure its turbidity, conductivity and volume, and collect all the outflowing liquid from the collector every day, pour it into the liquid collection bottle, and dry it all; b3: From the time the peristaltic pump quantitatively supplies liquid, take photos every half an hour for 24 to 48 hours, and collect the outflowing liquid every 3 hours to measure its turbidity, conductivity and volume; b4: From the time when the peristaltic pump quantitatively supplies the liquid, after 48 hours, take photos every 5 hours, take the outflowing liquid every 5 hours, and measure its turbidity, conductivity and volume. When the turbidity value of the outflowing liquid drops to the range of 0-10NTU, take the outflowing liquid every 50 hours, and measure its turbidity, conductivity and volume. When the turbidity value of the outflowing liquid drops to the range of 0-1NTU, take the outflowing liquid every 200 hours, and measure its turbidity, conductivity and volume. After one week or when the sample expansion change is not obvious within 24 hours, take photos every day; b5: until the sample has no obvious expansion change within 72 hours, take photos every 3 days; b6: Stop the peristaltic pump until the sample expands for one week and the turbidity of the collected liquid is between 0 and 1 NTU; b7: Take out the liquid inlet end of the peristaltic pump from the liquid supply bottle, connect the liquid outlet end of the peristaltic pump to the first liquid inlet tube, let in air and drain water, and control the air intake rate at 0.1~0.5ml / min. After drainage is completed, use clamps to clamp the first liquid inlet tube and the first liquid outlet tube that simulate the slit mechanism.

7. The simulated crack test method according to claim 4, characterized in that: In S4, the sample processing comprises the following steps: c1: Place the simulated crack mechanism in a refrigerator and quickly freeze it at -20°C, then quickly separate the lower mold from the upper mold, collect and weigh samples in circles according to the observed outward movement range of the material; c2: freeze-dry the samples collected in each circle, weigh them after drying, obtain the dry weight of each circle of samples, and calculate the moisture content; c3: Detect the material composition of each circle of samples, and summarize the moisture content of each circle of samples and the law of material movement outward; c4: Compare the weight of the dried material in the collected outflow liquid, the dry weight of the remaining material in the sample chamber, and the dry weight of the material in other structures in the simulated crack test device, evaluate the crack sealing and erosion resistance of the buffer / backfill material bentonite, and study the relationship between expansion deformation, whether erosion occurs and the amount of erosion and the sample composition, dry density, composition of the inflowing liquid, flow rate, crack opening and inclination.

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