A dry-wet cycle confinement constraint expansion rate automatic acquisition test instrument and method

Abstract

The invention relates to a dry-wet cycle side limit constraint expansion rate automatic collection test instrument and method, comprising a test chamber, an automatic expansion amount collection device, a wave velocity measuring device and a dry-wet cycle system. The test chamber comprises a base, a hollow cylinder and a metal cylinder, the metal cylinder is arranged at the center of the base and is used to place a rock sample, the hollow cylinder is coaxially sleeved on the base at the outer periphery of the metal cylinder, the automatic expansion amount collection device can measure the axial displacement of the rock sample in the metal cylinder, the wave velocity measuring device can test the transverse wave velocity and longitudinal wave velocity of ultrasonic waves in the rock sample, the dry-wet cycle system comprises a wet component and a dry component, the wet component is used to immerse the rock sample as a whole in a water body, the dry component comprises a drainage component and a heating and temperature control device, wherein the drainage component is used to discharge the water in the test chamber, and the heating and temperature control device is used to control the temperature in the test chamber. The invention can measure the expansion coefficient of weakly expansive rock and obtain a more accurate expansion rate.

Description

Technical Field

[0001] The invention relates to the technical field of rock expansion test instruments, in particular to an automatic collection test instrument and method for dry-wet cycle confinement constraint expansion rate. Background Art

[0002] The swelling rocks collected in nature are the product of long-term dry-wet cycles. The longer the excavation time, the more dry-wet cycles the swelling rocks have experienced, and the greater their swelling rate. Dry-wet cycles are natural conditions in which natural rocks often experience alternating dry and wet environments for a period of time. After being subjected to dry-wet cycles, the rocks will undergo complex physical and chemical reactions with water, which will lead to changes in the swelling characteristics of the rocks.

[0003] At present, some scholars have conducted some research on the expansion rate of rocks after dry-wet cycles, mainly focusing on the expansion rate of the same lithology under different dry-wet cycles. These results have important theoretical and practical significance for understanding the expansion characteristics of expansive rocks after dry-wet cycles. However, the current research still has the following deficiencies:

[0004] 1. The dry and wet parts of the indoor dry-wet cycle are separated and handled in different environments, which is inconsistent with the environment in which the actual engineering rock is located. During this environmental switch, the rock sample undergoes certain disturbances, resulting in results that are far from the actual results.

[0005] 2. The collection of expansion rate changes after indoor dry-wet cycles is mostly done manually, the results are not accurate enough, and it is time-consuming and laborious.

[0006] 3. When the rock expansion is less than 3%, the measured rock expansion is very small. If a displacement meter is used for monitoring, the error will be large, affecting the accuracy of the expansion rate. Summary of the invention

[0007] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and to provide a dry-wet cycle side confinement constraint expansion rate automatic collection test instrument and method. The dry-wet cycle side confinement constraint expansion rate automatic collection test instrument and method provide a wave velocity measurement device to detect the integrity of the inside of the rock, and construct the longitudinal and transverse wave velocity and expansion amount formula through multiple experiments to more accurately measure the expansion coefficient of the rock.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0009] A dry-wet cycle lateral confinement constraint expansion rate automatic collection tester comprises a test chamber, an automatic expansion amount collection device, a wave velocity measurement device and a dry-wet cycle system; the test chamber comprises a base, a hollow cylinder and a metal cylinder.

[0010] The metal cylinder is arranged at the center of the base and can be used to place rock samples; water-permeable holes are arranged around the bottom of the metal cylinder.

[0011] The hollow cylinder is coaxially sleeved on a base on the outer periphery of the metal cylinder.

[0012] The expansion amount automatic collection device comprises an axial displacement meter and an expansion amount automatic collection instrument connected with the axial displacement meter; the axial displacement meter can measure the axial displacement of the rock sample in the metal tube.

[0013] The wave velocity measuring device can test the transverse wave velocity and longitudinal wave velocity of ultrasonic waves in rock samples.

[0014] The wet-dry circulation system includes a wet component and a dry component; the wet component is used to immerse the rock sample as a whole in water; the dry component includes a drainage component and a heating and temperature control device; wherein the drainage component is used to discharge the water in the test room; the heating and temperature control device is used to control the temperature in the test room.

[0015] Preferably, the wave velocity measuring device comprises an ultrasonic controller and a longitudinal and transverse wave test channel connected to the ultrasonic controller; the longitudinal and transverse wave test channel comprises an ultrasonic generator and an ultrasonic receiver which are arranged on the outer periphery of the metal cylinder and located at the same height.

[0016] Preferably, there are two sets of longitudinal and transverse wave test channels, which are arranged at different axial heights of the metal cylinder.

[0017] Preferably, the heating and temperature control device comprises a heating jacket and an air blowing system; the heating jacket is arranged on the inner wall of the hollow cylinder, and the air blowing system is used to make the temperature in the test chamber evenly distributed.

[0018] Preferably, the above-mentioned wet component includes a watertight cylinder and a water inlet device; the watertight cylinder is coaxially arranged in the test chamber between the heating sleeve and the metal cylinder, and divides the test chamber into an outer cavity and an inner cavity; the bottom of the watertight cylinder is sealed and connected to the bottom of the test chamber, and the top height of the watertight cylinder is higher than the top height of the heating sleeve; the water inlet device is used to add water into the inner cavity.

[0019] A method for automatically collecting the expansion rate of dry-wet cycle confinement constraints, characterized by:

[0020] Step 1: Sample installation: Place the rock sample in a metal cylinder, and place filter paper and permeable stone at the bottom and top of the metal cylinder in sequence.

[0021] Step 2, determine the initial value of the axial displacement meter: the axial displacement meter is arranged vertically, the measuring end of the axial displacement meter is in contact with the top surface of the rock sample, and the non-measuring end of the axial displacement meter is connected to the automatic expansion amount collector; the automatic expansion amount collector can automatically collect the axial displacement measurement value of the axial displacement meter, and record the axial displacement measurement value collected at this time as the initial value H1 of the axial displacement meter.

[0022] Step 3, determination of expansion rate in a soaked state, specifically comprising the following steps:

[0023] Step 31: Soak in water: Use a wet assembly to soak the entire rock sample in water.

[0024] Step 32, determine the deformation value △H of the axial displacement meter: the automatic expansion volume collector collects and records the axial displacement measurement value once at the set time interval. After the experimental time exceeds 48 hours, when the difference between the axial displacement measurement values ​​collected by the automatic expansion volume collector for three consecutive times is no more than 0.001mm, the automatic expansion volume collector suspends collection and records the last collected axial displacement measurement value as the end value H2 of the axial displacement meter in the water-immersed state; then △H=H1-H2.

[0025] Step 33: Calculate the expansion rate V HP , the specific calculation formula is:

[0026]

[0027] When the calculated expansion rate V HP When the expansion rate is not less than the set expansion rate threshold, the rock and soil sample is called a strong expansion rock and soil sample, and the expansion rate V calculated by formula (1) is HP As the expansion rate of the soaked state to be measured; otherwise, the rock and soil sample is called a weakly expansive rock and soil sample, and the process goes to step 34.

[0028] Step 34, measuring the wave velocity value in the soaked state: when the expansion volume automatic collector in step 32 is suspended, the longitudinal and transverse wave test channels are started, and the transverse wave velocity V of the ultrasonic wave in the rock sample is measured according to the height and width of the rock sample. S and the longitudinal wave velocity V P .

[0029] Step 35: Calculate the expansion rate V of the weakly expansive rock and soil sample HP ′, the specific calculation formula is:

[0030] V HP ′=K(V S / V P )+C (2)

[0031] In formula (2), K is the correlation coefficient and C is the fitting constant. The K and C values ​​are calculated by the expansion rate V of the strongly expansive soil sample. HP , transverse wave velocity V S and the longitudinal wave velocity V P The relationship between them is fitted.

[0032] Step 4: Determination of expansion rate after the first dry-wet cycle, specifically comprising the following steps:

[0033] Step 41, drainage: The drainage component discharges the water in the test chamber that soaks the rock sample.

[0034] Step 42, heating: After all the water in step 41 is discharged, the heating temperature control device is started to control the temperature in the test room to the set temperature and maintain the set temperature for not less than 24 hours.

[0035] Step 43, repeat steps 31 to 35 to obtain the corresponding expansion rate of the rock and soil sample after the first dry-wet cycle.

[0036] Step 5. Repeat step 4 to obtain the expansion rate of the rock and soil sample after multiple dry-wet cycles.

[0037] Preferably, the set time interval in the above step 32 is to measure the deformation once every 10 minutes within the first hour, and then measure the deformation once every hour.

[0038] Preferably, there are two sets of longitudinal and transverse wave test channels in the above step 34; the transverse wave velocity V of the ultrasonic wave in the rock sample S and the longitudinal wave velocity V P Take the test mean of the transverse wave velocity or longitudinal wave velocity corresponding to the two sets of longitudinal and transverse wave test channels.

[0039] Preferably, the expansion rate threshold in the above step 33 is 3%.

[0040] Preferably, the height of the rock is smaller than the height of the metal cylinder, and the inner diameter of the metal cylinder is consistent with the diameter of the rock sample.

[0041] The present invention has the following beneficial effects:

[0042] 1. The dry and wet parts of the indoor dry-wet cycle of the present invention are connected together and are opened in a fixed position for dry-wet cycle, which is consistent with the environment of actual engineering rocks. In this process, the rock sample is not disturbed, and the dry-wet cycle conducted in the test is the same as the actual one.

[0043] 2. Construct the relationship between the integrity index and expansion rate of the rock, and fully consider that the expansion rate is affected not only by the chemical composition of the rock itself, but also by the integrity of the rock. Fully consider the cracks inside the rock, and the expansion rate result is rigorous.

[0044] 3. Automatic data collection equipment is used to collect the change in expansion rate after indoor dry-wet cycles, thus avoiding errors caused by human factors.

[0045] 4. It can measure the expansion coefficient of weak expansion rock and make the expansion coefficient more accurate by combining the wave velocity formula. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1It is a front view of the automatic collection tester for the dry-wet cycle confinement constraint expansion rate of the present invention.

[0047] Figure 2 It is a top view of the automatic collection tester for the dry-wet cycle confinement constraint expansion rate of the present invention.

[0048] Figure 3 It is a bottom view of the automatic collection tester for the dry-wet cycle confinement constraint expansion rate of the present invention.

[0049] Figure 4 The utility model relates to a water-proof cylinder of the automatic collection tester of the dry-wet cycle lateral confinement constraint expansion rate of the present invention.

[0050] Among them are:

[0051] 10. Test chamber; 11. Base; 12. Hollow cylinder; 13. Metal cylinder; 14. Cover; 15. Bolts;

[0052] 20. Automatic expansion amount collection device; 21. Axial displacement meter; 22. Automatic expansion amount collection instrument; 23. Axial displacement meter fixing device;

[0053] 30. Wave velocity measuring device; 31. Ultrasonic controller; 32. Longitudinal and transverse wave test channel; 321. Ultrasonic generator 1; 322. Ultrasonic receiver 1; 323. Ultrasonic generator 2; 324. Ultrasonic receiver 2; 33. Slot of acoustic wave module;

[0054] 40. Dry-wet circulation system; 41. Water inlet assembly; 411. Water inlet tank; 412. Water inlet; 413. Water inlet switch; 42. Water barrier;

[0055] 43. Drainage assembly; 431. Inner water outlet; 432. Outer water outlet; 433. Water outlet valve; 434. Water outlet tank;

[0056] 44. Heating and temperature control device; 441. Heating jacket; 442. Air blowing system; 443. Temperature controller; 444. Temperature monitor; 445. Power supply; 446. Heating circuit; 447. Temperature module slot. DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0058] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0059] like Figure 1 As shown, the dry-wet cycle confinement constraint expansion rate automatic collection tester includes a test chamber 10, an expansion amount automatic collection device 20, a wave velocity measurement device 30 and a dry-wet cycle system 40.

[0060] The test chamber 10 includes a base 11, a hollow cylinder 12, a metal cylinder 13, a cover 14 and bolts 15;

[0061] The metal cylinder 13 is arranged at the center of the base 11 and can be used to place rock samples.

[0062] The hollow cylinder 12 is coaxially sleeved on the base 11 on the outer periphery of the metal cylinder 13 .

[0063] The cover 14 and the base 11 are fixed to the hollow cylinder 12 by eight bolts 15 so that the test chamber 10 forms a closed container, thereby avoiding the error of the expansion rate parameter measured by the axial displacement meter 21 during the test.

[0064] The hollow cylinder 12 is preferably a hollow organic glass cylinder, and the metal cylinder 13 is preferably an iron cylinder. Water-permeable holes are preferably provided around the bottom thereof to facilitate drainage.

[0065] The expansion amount automatic collection device 20 comprises an axial displacement meter 21 , an expansion amount automatic collection instrument 22 and an axial displacement meter fixing device 23 .

[0066] The measuring end of the axial displacement meter 21 contacts the top of the rock sample, and the other end is connected to the automatic expansion volume collector 22 . The axial displacement meter 21 can measure the axial displacement of the rock sample in the metal cylinder 13 .

[0067] The axial displacement meter fixing device 23 is centrally installed above the cover 14, and the axial displacement meter 21 can be placed in the middle.

[0068] The expansion automatic collector 22 automatically collects the result of the axial displacement meter 21 fixed on the axial displacement meter fixing device 23 to obtain the lateral restraint expansion rate under different dry-wet cycle numbers.

[0069] The wave velocity measuring device 30 comprises an ultrasonic controller 31, longitudinal and transverse wave test channels 32 and an acoustic wave module slot 33; the wave velocity measuring device 30 can test the transverse wave velocity and longitudinal wave velocity of ultrasonic waves in a rock sample.

[0070] The acoustic wave module slot 33 is vertically penetrated on the base 11 , allowing the electric wire to pass through and wrapping the electric wire so that water cannot flow out of the acoustic wave module slot 33 .

[0071] The ultrasonic controller 31 is located below the base 11 and is connected to the longitudinal and transverse wave test channel 32 through the acoustic wave module slot 33 .

[0072] There are preferably two sets of longitudinal and transverse wave test channels 32, which are arranged at different axial heights of the metal cylinder 13. Each set of longitudinal and transverse wave test channels 32 includes an ultrasonic generator and an ultrasonic receiver, and each set of longitudinal and transverse wave test channels 32 can test the horizontal propagation velocity and longitudinal propagation velocity of ultrasonic waves in the rock sample at the corresponding height. The longitudinal and transverse wave test channels 32 in this embodiment include ultrasonic generator 1 321, ultrasonic receiver 1 322, ultrasonic generator 2 323 and ultrasonic receiver 2 324.

[0073] The wet-dry cycle system 40 includes a wet component and a dry component.

[0074] The wet assembly includes a water inlet assembly 41 and a water barrier 42, which are used to immerse the entire rock sample in water.

[0075] The watertight cylinder 42 is coaxially arranged in the test chamber 10 between the side wall of the test chamber 10 and the metal cylinder 13, and divides the test chamber 10 into an outer cavity and an inner cavity; the bottom of the watertight cylinder 42 is sealedly connected to the bottom of the test chamber 10. When in use, the water in the watertight cylinder 42 is controlled so that its water level exceeds the height of the metal cylinder 13 but does not exceed the height of the watertight cylinder 42.

[0076] The water inlet assembly 41 includes a water inlet tank 411 , a water inlet 412 and a water inlet switch 413 .

[0077] The water inlet 412 is set on the cover 14 from top to bottom. The water inlet tank 411 is located outside the test chamber 10 and is connected to the water inlet 412 through a pipe. A water inlet switch 413 is provided above the pipe to facilitate the control of water output. The end of the pipe is located on the inner side of the water barrier 42.

[0078] The water inlet assembly 41 is used to add water into the inner cavity so that the sample is fully immersed in water.

[0079] The dry component includes a drainage component 43 and a heating and temperature control device 44.

[0080] The drainage component 43 includes an inner water outlet 431 , an outer water outlet 432 , a water outlet valve 433 , a water outlet tank 434 and a permeable stone. The drainage component 43 is used to discharge the water in the test chamber 10 .

[0081] The inner water outlet 431 and the outer water outlet 432 are arranged on the base 11 in a vertically continuous manner. The upper end of the pipe connected to the inner water outlet 431 and the outer water outlet 432 is flush with the upper surface of the base 11, and the lower end of the pipe connected to the inner water outlet 431 and the outer water outlet 432 extends out of the lower surface of the base 11. The inner water outlet 431 is located between the metal cylinder 13 and the waterproof cylinder 42, and the outer water outlet 432 is located between the waterproof cylinder 42 and the hollow cylinder 12. If the water exceeds the waterproof cylinder 42, the water will be discharged from the outer water outlet 432.

[0082] The water outlet tank 434 is placed below the pipe connecting the inner water outlet 431 and the outer water outlet 432 to accommodate the discharged water.

[0083] The water outlet valve 433 is installed on the portion of the pipe connected to the inner water outlet 431 extending out of the base 11 .

[0084] The permeable stone is placed at the bottom of the metal cylinder 13 to facilitate the discharge of water in the metal cylinder 13.

[0085] The heating and temperature control device 44 includes a heating sleeve 441 , an air blowing system 442 , a temperature controller 443 , a temperature monitor 444 , a power supply 445 , a heating circuit 446 and a temperature module slot 447 .

[0086] The heating jacket 441 is arranged on the inner wall of the hollow cylinder 12, and can heat the inside of the test chamber 10. The top height of the water-proof cylinder 42 is higher than the top height of the heating jacket 441, so that the heating jacket 441 can be isolated from water to prevent the heating jacket 441 from being damaged by water.

[0087] The temperature controller 443 is located outside the test chamber 10 , connected to the power supply 445 , and connected to the heating jacket 441 via a heating line 446 .

[0088] The temperature module slot 447 is vertically penetrated on the base 11 and is located between the heating sleeve 441 and the water-isolating tube 42 .

[0089] The temperature monitor 444 is installed on the temperature module slot 447 and is connected to the temperature controller 443 through the temperature module slot 447 to monitor the temperature change in real time.

[0090] The air blowing system 442 is disposed on the cover 14 in a vertically extending manner. When the temperature reaches the target value, the air blowing system 442 is turned on. The air blowing system 442 is used to evenly distribute the temperature in the test chamber 10 and maintain the temperature in the test chamber 10 until the target time is reached.

[0091] A dry-wet cycle confinement constraint expansion rate automatic collection test method comprises the following steps.

[0092] Step 1, sample installation: unscrew the bolts 15 on the top of the test chamber 10, take out the cover 14, place permeable stone and filter paper in sequence at the bottom of the metal cylinder 13, place the rock sample in the metal cylinder 13, the height of the rock is less than the height of the metal cylinder 13, and the inner diameter of the metal cylinder 13 is consistent with the diameter of the rock sample, and place filter paper and permeable stone in sequence on the top.

[0093] Step 2, determine the initial value of the axial displacement meter 21: the axial displacement meter 21 is arranged vertically, the measuring end of the axial displacement meter 21 is in contact with the top surface of the rock sample, the initial measurement position of the axial displacement meter 21 is adjusted to a reasonable range, and the non-measuring end of the axial displacement meter 21 is connected to the automatic expansion volume collector 22; the automatic expansion volume collector 22 can automatically collect the axial displacement measurement value of the axial displacement meter 21. The automatic expansion volume collector 22 is preferably used to collect data every 10 minutes until the 3 readings remain unchanged, and then the next step can be carried out, and the axial displacement measurement value collected at this time is recorded as the initial value H1 of the axial displacement meter 21.

[0094] Step 3, determination of expansion rate in a soaked state, specifically comprising the following steps:

[0095] Step 31, soaking in water: open the water inlet switch 413 and close the water outlet valve 433, slowly add the water in the water inlet tank 411 into the test chamber 10, when the water level in the test chamber 10 just exceeds the height of the metal cylinder 13, close the water inlet switch 413, and immerse the rock sample in the water as a whole.

[0096] Step 32, determining the deformation value △H of the axial displacement meter 21: the automatic expansion volume collector 22 measures the deformation once every 10 minutes within the first hour, and then measures the deformation once every hour, collects and records the axial displacement measurement value once. After the experimental time exceeds 48 hours, when the difference between the axial displacement measurement values ​​collected by the automatic expansion volume collector 22 for three consecutive times is not greater than 0.001mm, the automatic expansion volume collector 22 suspends collection and records the last collected axial displacement measurement value as the end value H2 of the axial displacement meter 21 in the soaked state; then △H=H1-H2.

[0097] Step 33: Calculate the expansion rate V HP , the specific calculation formula is:

[0098]

[0099] When the calculated expansion rate V HPWhen the expansion rate is not less than the set expansion rate threshold (preferably 3%), the soil sample is called a strong expansion soil sample, and the expansion rate V calculated by formula (1) is HP As the expansion rate of the soaked state to be measured; otherwise, the rock and soil sample is called a weakly expansive rock and soil sample, and the process goes to step 34.

[0100] Step 34, measuring the wave velocity value in the soaked state: when the expansion volume automatic collector 22 of step 32 is suspended, the longitudinal and transverse wave test channels 32 are started. The longitudinal and transverse wave test channels 32 are preferably two sets. According to the height and width of the rock and soil sample, the transverse wave velocity V of the ultrasonic wave in the rock sample is measured. S and the longitudinal wave velocity V P When there are two sets of longitudinal and transverse wave test channels 32, the transverse wave velocity V S and the longitudinal wave velocity V P Take the average transverse wave velocity and the average longitudinal wave velocity respectively.

[0101] Step 35: Calculate the expansion rate V of the weakly expansive rock and soil sample HP ′, the specific calculation formula is:

[0102] V HP ′=K(V S / V P )+C (2)

[0103] In formula (2), K is the correlation coefficient and C is the fitting constant. The K and C values ​​are calculated by the expansion rate V of the strongly expansive soil sample. HP , transverse wave velocity V S and the longitudinal wave velocity V P The relationship between them is fitted.

[0104] Step 4: Determination of expansion rate after the first dry-wet cycle, specifically comprising the following steps:

[0105] Step 41, drainage: the water in the water barrier 42 is discharged to the water outlet tank 434 through the water outlet valve 433 and the inner water outlet 431.

[0106] Step 42, heating: After all the water in step 41 is discharged, the heating temperature control device 44 is started to control the temperature in the test chamber 10 at 105° C. and maintain the set temperature for not less than 24 hours.

[0107] Step 43, repeat steps 31 to 35 to obtain the corresponding expansion rate of the rock and soil sample after the first dry-wet cycle.

[0108] Step 5, repeat step 4, wherein the temperature of step 42 can be set to any set temperature, and the heating time can be set to any time, and the expansion rate of the rock and soil sample under certain dry and wet temperature, time, and number of times can be statistically calculated.

[0109] Step 6: The expansion volume automatic collector 22 and the ultrasonic controller 31 collect statistical results: plot the expansion rate and wave velocity of the sample under different dry-wet cycles as a function of dry-wet temperature, time, and number of times.

[0110] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A method for automatically collecting the expansion rate of the side confinement restraint in dry and wet cycles, characterized in that: The steps include: Step 1: Sample installation: Place the rock sample in a metal cylinder, and place filter paper and permeable stone at the bottom and top of the metal cylinder in sequence; Step 2, determining the initial value of the axial displacement meter: the axial displacement meter is arranged vertically, the measuring end of the axial displacement meter is in contact with the top surface of the rock sample, and the non-measuring end of the axial displacement meter is connected to the expansion amount automatic collector; the expansion amount automatic collector can automatically collect the axial displacement measurement value of the axial displacement meter, and record the collected axial displacement measurement value at this time as the initial value H1 of the axial displacement meter; Step 3, determination of expansion rate in a soaked state, specifically comprising the following steps: Step 31, soaking in water: using a wet assembly to soak the entire rock sample in water; Step 32, determining the deformation value △H of the axial displacement meter: the expansion amount automatic collector collects and records the axial displacement measurement value once at the set time interval. After the experimental time exceeds 48 hours, when the difference between the axial displacement measurement values ​​collected by the expansion amount automatic collector for three consecutive times is not greater than 0.001mm, the expansion amount automatic collector pauses the collection and records the last collected axial displacement measurement value as the end value H2 of the axial displacement meter in the water-immersed state; then △H=H1-H2; Step 33: Calculate the expansion rate V HP , the specific calculation formula is: When the calculated expansion rate V HP When the expansion rate is not less than the set expansion rate threshold, the rock and soil sample is called a strong expansion rock and soil sample, and the expansion rate V calculated by formula (1) is HP as the expansion rate of the soaked state to be measured; otherwise, the rock and soil sample is called a weakly expansive rock and soil sample, and the process goes to step 34; Step 34, measuring the wave velocity value in the soaked state: when the expansion volume automatic collector in step 32 is suspended, the longitudinal and transverse wave test channels are started, and the transverse wave velocity V of the ultrasonic wave in the rock sample is measured according to the height and width of the rock sample. S and the longitudinal wave velocity V P ; Step 35: Calculate the expansion rate V of the weakly expansive rock and soil sample HP ′, the specific calculation formula is: V HP ′=K(V S / V P )+C (2) In formula (2), K is the correlation coefficient and C is the fitting constant. The K and C values ​​are calculated by the expansion rate V of the strongly expansive soil sample. HP , transverse wave velocity V S and the longitudinal wave velocity V P The relationship between them is fitted; Step 4: Determination of expansion rate after the first dry-wet cycle, specifically comprising the following steps: Step 41, drainage: the drainage component discharges the water in the test chamber that soaks the rock sample; Step 42, heating: when all the water in step 41 is discharged, the heating temperature control device is started to control the temperature in the test room to the set temperature, and maintain the set temperature for not less than 24 hours; Step 43, repeat steps 31 to 35 to obtain the expansion rate of the rock and soil sample after the first dry-wet cycle; Step 5, repeat step 4 to obtain the expansion rate of the rock and soil sample after multiple dry-wet cycles.

2. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 1 is characterized by: The set time interval in step 32 is to measure the deformation once every 10 minutes in the first hour, and then measure the deformation once every hour.

3. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 1 is characterized in that: There are two sets of longitudinal and transverse wave test channels in step 34; the transverse wave velocity V of ultrasonic wave in rock sample S and the longitudinal wave velocity V P Take the test mean of the transverse wave velocity or longitudinal wave velocity corresponding to the two sets of longitudinal and transverse wave test channels.

4. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 1 is characterized by: In step 33, the expansion rate threshold is 3%.

5. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 1 is characterized in that: The height of the rock is smaller than the height of the metal cylinder, and the inner diameter of the metal cylinder is consistent with the diameter of the rock sample.

6. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 1 is characterized by: An automatic collection tester for expansion rate based on dry-wet cycle side confinement constraint, comprising a test chamber, an automatic expansion collection device, a wave velocity measurement device and a dry-wet cycle system; The test chamber includes a base, a hollow cylinder and a metal cylinder; The metal cylinder is set in the center of the base and can be used to place rock samples; water holes are opened around the bottom of the metal cylinder; The hollow cylinder is coaxially sleeved on a base around the outer periphery of the metal cylinder; The expansion amount automatic collection device includes an axial displacement meter and an expansion amount automatic collection instrument connected to the axial displacement meter; the axial displacement meter can measure the axial displacement of the rock sample in the metal tube; The wave velocity measuring device can test the transverse wave velocity and longitudinal wave velocity of ultrasonic waves in rock samples; The wet-dry cycle system includes a wet component and a dry component; The wet assembly is used to immerse the rock specimen as a whole in a body of water; The dry component includes a drainage component and a heating and temperature control device; wherein the drainage component is used to discharge the water in the test chamber; the heating and temperature control device is used to control the temperature in the test chamber.

7. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 6 is characterized in that: The wave velocity measuring device comprises an ultrasonic controller and a longitudinal and transverse wave test channel connected to the ultrasonic controller; the longitudinal and transverse wave test channel comprises an ultrasonic generator and an ultrasonic receiver which are arranged on the outer periphery of the metal cylinder and are located at the same height.

8. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 7 is characterized in that: There are two sets of longitudinal and transverse wave test channels, which are arranged at different axial heights of the metal cylinder.

9. The automatic collection test method for dry-wet cycle confinement expansion rate according to claim 6 is characterized by: The heating and temperature control device comprises a heating jacket and an air blowing system; the heating jacket is arranged on the inner wall of the hollow cylinder, and the air blowing system is used to make the temperature in the test chamber evenly distributed.

10. The automatic collection test method for dry-wet cycle confinement constraint expansion rate according to claim 9, characterized in that: The wet components include the water block and water inlet; The watertight tube is coaxially arranged in the test chamber between the heating jacket and the metal tube, and divides the test chamber into an outer cavity and an inner cavity; The bottom of the watertight shell is sealed and connected to the bottom of the test chamber, and the top height of the watertight shell is higher than the top height of the heating jacket; The water inlet device is used to add water into the inner cavity.

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