Soil body disintegration rate test method

Abstract

The invention discloses a soil disintegration rate test method, a soil disintegration test device comprises a bearing platform, a mass collection system, a water tank, a perforated screen and a water-soluble film, the water tank is arranged below the bearing platform, and the mass collection system is arranged on the bearing platform; the sample is wrapped with a water-soluble film, and the quality acquisition system acquires disintegration quality data of the sample in real time. According to the soil mass disintegration rate testing method, the tested sample is wrapped by the water-soluble film, so that the sample is completely immersed in water and disintegrated after being stabilized, and the disintegration data can be accurately acquired under the condition that the sample is not disturbed; in the test process, the actual volume of a sample with irregular volume, especially an undisturbed sample, can be measured, and the dry density of a soil body is determined; through the water absorption test of the sample, the disintegration test calculation method is accurately corrected according to the water absorption rate curve, and the accurate disintegration rate is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of geotechnical engineering analysis and testing, and in particular to a soil disintegration rate test method. Background Art

[0002] The water disintegration test of rock and soil is an experimental method used to study the disintegration and destruction of soil under water conditions, and its purpose is to evaluate the stability and erosion resistance of soil or rock under different conditions. In the specific test process, soil samples in different saturation states are usually used and immersed in water to simulate the erosion of soil by water in the natural environment. The disintegration rate is used to characterize the speed or rate at which soil or rock disintegrates or breaks under specific conditions. This rate usually describes the degree of disintegration or breakage of soil or rock within a certain period of time, and can be used to evaluate the stability and erosion resistance of soil or rock. Through the disintegration test, the disintegration rate, disintegration form and changing law of soil or rock under the influence of the external environment can be determined, thereby providing important reference for engineering design, geological disaster prevention and control, soil erosion research, etc.

[0003] At present, the disintegration test of rock and soil has the following main disadvantages: (1) One of the most important steps in the disintegration test is to put the sample into the water. The moment the sample contacts the water, it absorbs water and disintegrates. Especially for samples with a fast disintegration rate, the sample begins to disintegrate before the data is read. (2) The sample will shake from the time it is completely filled with water. The shaking of the sample will affect the stability of data reading. Most importantly, the shaking will affect the disintegration rate of the soil, resulting in large human errors. (3) During the sample immersion disintegration test, the soil will absorb water while disintegrating, especially for samples with low saturation. The current disintegration test calculations basically do not take this effect into account, and the resulting disintegration rate is too small and is not the actual disintegration rate of the rock and soil. Summary of the invention

[0004] The purpose of the present invention is to provide a soil disintegration rate test method, which effectively avoids the related problems raised in the background technology by wrapping the rock and soil with a hydrolytic film and conducting a water immersion test, and then corrects the disintegration test data through a water absorption rate test of the sample to obtain more accurate disintegration data.

[0005] To achieve the above object, the present invention provides a soil disintegration rate test method, which uses a soil disintegration test device for testing, the test device comprising a cap, a mass collection system, a water tank, a perforated screen, a water-soluble film and a beaker, the water tank is arranged below the cap, and the mass collection system is arranged on the cap; the test method comprises the following steps:

[0006] S1. Sample preparation: Several ring knife samples were prepared by static compaction method, and multiple samples were obtained after demoulding, moisturizing and standing;

[0007] S2, using a water-soluble film to seal and wrap the sample, and performing a vacuum treatment on the sample;

[0008] S3, disintegration test: first, place the sample wrapped with the water-soluble film on the perforated screen suspended on the mass collection system, and then immerse the perforated screen and the sample in the water in the water tank; the mass collection system starts to collect disintegration test data, and stops collecting after the sample is completely disintegrated and the data is stable; in the initial state, the total mass reading of the perforated screen and the sample placed thereon is recorded as m 0筛 The mass reading of the perforated sieve immersed in water without the sample is recorded as m 筛 ;

[0009] S4. Water absorption test: After the disintegration test is completed, the perforated screen is replaced with a beaker and hung on the mass acquisition system, and then the parallel sample wrapped with a water-soluble film is placed in the beaker, and then the beaker is completely immersed in the water in the water tank; the mass acquisition system starts to collect data and stops collecting after the water absorption is complete and the data is stable; in the initial state, the total mass reading of the beaker and the sample is recorded as m 0杯 The reading of the beaker immersed in water without the sample is recorded as m 杯 ;

[0010] S5. Calculate using the data collected in step S3 and step S4 to finally obtain the sample disintegration rate.

[0011] Furthermore, the specific calculation method of step S5 is: the relative disintegration amount y is calculated using the following formula 1) t :

[0012]

[0013] Among them, m t Represents the balance reading at a certain time t during the disintegration test, which represents the sum of the undisintegrated part of the sample and the water absorbed by the undisintegrated part and the mass of the perforated sieve; m t ' is the mass of the uncollapsed soil at a certain time t, that is, the mass of this part does not include the mass of its absorbed water, as shown in the following formula 2):

[0014]

[0015] The water absorbed by the undisintegrated part is the total water mass absorbed by the sample within the time t minus the water mass completely absorbed by the disintegrated part. The water absorption mass m corresponding to a certain time t during the water absorption test is wtAs shown below:

[0016] m wt =m 吸t -m 0杯 3);

[0017]

[0018] In the formula, m 吸t is the balance reading corresponding to a certain time t during the water absorption test, Δt 吸 is the corresponding consumption time, Δm wt The average water absorption rate corresponding to a certain time t during the water absorption test;

[0019] Wherein, through formula 2)m t ' is expressed as the following formula 5):

[0020]

[0021] Substituting equation 5) into equation 1), the corrected relative disintegration amount is:

[0022]

[0023] Furthermore, the water-soluble film is a bag-like structure made of a PVA water-soluble film, the thickness of the water-soluble film is 0.02 to 0.05 mm, and the dissolution time of the water-soluble film is 5 to 8 seconds.

[0024] Furthermore, the thickness of the water-soluble film is 0.025 to 0.04 mm, and the dissolution time of the water-soluble film is 5 to 8 seconds.

[0025] Furthermore, the mass acquisition system includes an electronic balance, a computer acquisition system and a hanging rope, wherein the computer acquisition system acquires data of the electronic balance in real time, one end of the hanging rope is connected to the electronic balance, and the other end is used to connect to the perforated screen or the beaker.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention discloses a soil disintegration rate test method, which wraps the tested sample with a water-soluble film so that the sample is completely immersed in water and disintegrates after being stabilized, thereby ensuring that the sample is not disturbed and disintegration data is accurately collected; during the test, the actual volume of the irregular volume sample, especially the original sample, can be measured to clarify the dry density of the soil; the test method of the present invention performs a water absorption test on the sample, and accurately corrects the disintegration test calculation method according to the water absorption rate curve, thereby finally obtaining an accurate disintegration rate.

[0028] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0030] Figure 1 It is a structural schematic diagram of a soil disintegration test device of the present invention;

[0031] Figure 2 It is a schematic diagram of a soil disintegration test device used for a water absorption test of the present invention;

[0032] Figure 3 It is a curve diagram showing the relationship between water absorption mass and time in a soil disintegration rate test method of the present invention;

[0033] Figure 4 It is a relationship curve between the undisintegrated amount and time of a soil disintegration rate test method of the present invention;

[0034] Figure 5 It is a relationship curve between relative disintegration amount and time of a soil disintegration rate test method of the present invention;

[0035] Among them, 1-supporting platform; 2-electronic balance; 3-water tank; 4-perforated sieve; 5-water-soluble membrane; 6-computer acquisition system; 7-sample; 8-beaker; 9-hanging rope. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0037] See also Figure 1A soil disintegration test device according to an embodiment of the present invention comprises a cap 1, a mass collection system, a water tank 3, a perforated screen 4 and a water-soluble film 5. The water tank 3 is arranged below the cap 1, and the mass collection system is arranged on the cap 1. When the disintegration test is carried out, the perforated screen 4 is suspended on the mass collection system, and is used to immerse the sample 7 placed on the perforated screen 4 in the water tank 3 for the disintegration test. The sample 7 is wrapped with a water-soluble film 5 on the outside, and the mass collection system collects the disintegration mass data of the sample 7 in real time. The test device also comprises a beaker 8. When the water absorption test is carried out, the beaker 8 is suspended on the mass collection system, and the mass collection system collects the water absorption mass data of the sample 7 in real time. Among them, the mass collection system comprises an electronic balance 2, a computer collection system 6 and a hanging rope 9. The computer collection system 6 collects the data of the electronic balance 2 in real time. One end of the hanging rope 9 is connected to the electronic balance 2, and the other end is used to connect to the perforated screen 4 or the beaker.

[0038] The present invention provides a soil disintegration rate test method, using the soil disintegration test device described above, and the test method includes the following steps:

[0039] S1. Preparation of samples: Several ring knife samples with a certain moisture content are prepared by static compaction method. After demoulding and keeping them moist, multiple samples 7 are obtained.

[0040] S2. The sample 7 is sealed and wrapped with a water-soluble film 5. The water-soluble film 5 is a bag-shaped structure made of a PVA water-soluble film. The thickness of the water-soluble film 5 is 0.02 to 0.05 mm, and the dissolution time of the water-soluble film 5 is 5 to 8 seconds. It should be noted that if the thickness of the water-soluble film is uniform, the decomposition time of the water-soluble film 5 wrapped on the sample is uniform. On the other hand, after the water-soluble film 5 is partially ruptured due to water-soluble rupture, the water-soluble film 5 is thin as a whole and will completely rupture under the action of water pressure. Therefore, it will not cause uneven water-solubility and affect the overall disintegration of the sample. After the sample is wrapped, the water-soluble film 5 is slowly vacuumed and sealed (i.e., the sample 7 is vacuumed), so as to avoid excessive vacuum pressure from damaging the sample.

[0041] S3, disintegration test: first, place the sample 7 wrapped with the water-soluble film 5 on the perforated screen 4, and then quickly immerse the perforated screen 4 and the sample 7 in the water in the water tank 3; then the mass acquisition system starts to collect data, and the total mass reading of the perforated screen 4 and the sample 7 placed thereon is recorded as m 0筛 The reading when the perforated screen is immersed in water without a sample is m 筛 , stop collecting data after sample 7 is completely disintegrated and the data is stable; during the disintegration test, the corresponding reading of the mass collection system at a certain moment t is m t .

[0042] S4. Water absorption test: After the disintegration test is completed, the perforated screen 4 is replaced with a beaker 8, and the beaker 8 is hung on the mass collection system. Then, the parallel sample 7 wrapped with the water-soluble film 5 is placed in the beaker 8, and then the beaker 8 is quickly immersed in the water in the water tank 3 to start collecting data. At this time, the total mass reading of the beaker 8 and the sample 7 is recorded as m 0杯 The reading when beaker 8 is immersed in water without sample 7 is recorded as m 杯 ; During the water absorption test, the reading of the mass acquisition system corresponding to a certain time t is m 吸t , stop collecting data after the water is completely absorbed and the data is stable.

[0043] S5. Calculate the sample disintegration rate using the data collected in step S3 and step S4.

[0044] The modified calculation method for the soil disintegration rate test method of the present invention taking into account the water absorption of the sample is as follows: Specifically, the relative disintegration amount y is calculated using the following formula 1) t :

[0045]

[0046] Among them, m t Represents the balance reading at a certain time t during the disintegration test, which represents the sum of the undisintegrated part of the sample and the water absorbed by the undisintegrated part and the mass of the perforated sieve; m t ' is the mass of the uncollapsed soil at a certain time t, and the mass of this part does not include the mass of its absorbed water, as shown in the following formula 2):

[0047]

[0048] The water absorbed by the undisintegrated part is the total water mass absorbed by the sample within the time t minus the water mass completely absorbed by the disintegrated part. The water absorption mass m corresponding to a certain time t during the water absorption test is wt As shown below:

[0049] m wt =m 吸t -m 0杯 3);

[0050]

[0051] In the formula, m 吸t is the balance reading corresponding to a certain time t during the water absorption test, Δt 吸 is the corresponding consumption time, Δm wt The average water absorption rate corresponding to a certain time t during the water absorption test;

[0052] Wherein, through formula 2)m t ' is expressed as the following formula 5):

[0053]

[0054] Substituting equation 5) into equation 1), the corrected relative disintegration amount is:

[0055]

[0056] Example

[0057] In this embodiment, a sample 7 with a diameter of 61.8 mm and a height of 20 mm was prepared, and the dry density was 1.6 g / cm 3 The initial moisture content was 23%. After being wrapped by the water-soluble film 5, the disintegration test and water absorption test were carried out. The experimental results are as follows Figure 3 and Figure 4 As shown, Figure 3 The relationship curve between the water absorption mass and time is m 吸t -m0~t curve, Figure 4 The relationship between the undisintegrated amount and time is m t ~t curve.

[0058] Substitute the test results into the above formula, where the test results of the relevant parameters are m 0筛 =42.26g, m 0杯 =42.36g, m 筛 = 1.18g, the total amount of water absorbed by the soil changes with time as shown in Figure 3 As shown, the final total mass of water absorbed is m wt =9.28g. Figure 4 is the balance reading at a certain moment in the disintegration process m t The curve of change over time, the data at a certain time t is substituted into formula 6 one by one. In order to simplify the calculation, it is assumed that the time consumption of water absorption test and disintegration test is synchronized, both of which are 0.3h, then tΔm wt =Δt 吸 Δm wt =m wt , thus obtaining the final relative disintegration amount curve of the sample (final relative disintegration amount), the results are as follows Figure 5 shown.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A soil disintegration rate test method, characterized in that: A soil disintegration test device is used for testing, the test device comprising a foundation (1), a mass collection system, a water tank (3), a perforated screen (4), a water-soluble film (5) and a beaker (8), the water tank (3) being arranged below the foundation (1), and the mass collection system being arranged on the foundation (1); the test method comprising the following steps: S1. Sample preparation: a number of ring knife samples are prepared by static compaction method, and multiple samples are obtained after demoulding, moisturizing and standing still (7); S2, using a water-soluble film (5) to seal and wrap the sample (7), and performing a vacuum treatment on the sample (7); S3, firstly placing the sample (7) wrapped with the water-soluble film (5) on the perforated screen (4) suspended on the mass collection system, and then immersing the perforated screen (4) and the sample (7) in the water in the water tank (3); the mass collection system starts to collect disintegration test data, and stops collecting after the sample (7) is completely disintegrated and the data is stable; in the initial state, the total mass reading of the perforated screen (4) and the sample (7) placed thereon is recorded as m 0筛 The mass reading of the perforated sieve (4) immersed in water without the sample (7) is recorded as m 筛 ; S4. After the disintegration test is completed, the perforated screen (4) is first replaced with a beaker (8) and hung on the mass acquisition system, and then the parallel sample (7) wrapped with the water-soluble film (5) is placed in the beaker (8), and then the beaker (8) is completely immersed in the water in the water tank (3); the mass acquisition system starts to collect data and stops collecting after the water absorption is complete and the data is stable; in the initial state, the total mass reading of the beaker (8) and the sample (7) is recorded as m 0杯 The reading of the beaker (8) immersed in the water without the sample (7) is recorded as m 杯 ; S5. Calculate using the data collected in step S3 and step S4 to finally obtain the sample disintegration rate.

2. The soil disintegration rate test method according to claim 1, characterized in that: The specific calculation method of step S5 is: the relative disintegration amount y is calculated using the following formula 1) t : Among them, m t Represents the balance reading at a certain time t during the disintegration test, which represents the sum of the undisintegrated part of the sample and the water absorbed by the undisintegrated part and the mass of the perforated sieve; m t ' is the mass of the uncollapsed soil at a certain time t, that is, the mass of this part does not include the mass of its absorbed water, as shown in the following formula 2): The water absorbed by the undisintegrated part is the total water mass absorbed by the sample within the time t minus the water mass completely absorbed by the disintegrated part. The water absorption mass m corresponding to a certain time t during the water absorption test is wt As shown below: m wt =m 吸t -m 0杯 3); In the formula, m 吸t is the balance reading corresponding to a certain time t during the water absorption test, Δt 吸 is the corresponding consumption time, Δm wt The average water absorption rate corresponding to a certain time t during the water absorption test; Wherein, through formula 2)m t ' is expressed as the following formula 5): Substituting equation 5) into equation 1), the corrected relative disintegration amount is:

3. The soil disintegration rate test method according to claim 1, characterized in that: The water-soluble film (5) is a bag-shaped structure made of a PVA water-soluble film. The thickness of the water-soluble film (5) is 0.02 to 0.05 mm, and the dissolution time of the water-soluble film (5) is 5 to 8 seconds.

4. The soil disintegration rate test method according to claim 3, characterized in that: The thickness of the water-soluble film (5) is 0.025 to 0.04 mm, and the dissolution time of the water-soluble film (5) is 5 to 8 seconds.

5. The soil disintegration rate test method according to claim 1, characterized in that: The mass collection system comprises an electronic balance (2), a computer collection system (6) and a hanging rope (9), wherein the computer collection system (6) collects data of the electronic balance (2) in real time, and one end of the hanging rope (9) is connected to the electronic balance (2), and the other end is used to connect to the perforated screen (4) or the beaker (8).

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