A method for measuring a dual-t2 cutoff of a porous discontinuity

Abstract

The present application relates to the field of underground construction, and is a kind of porous discontinuous structure dual-T2 cutoff value measurement method.The method is based on the T2 spectrum measured after the saturation soft soil is frozen, first determines the turning freezing time, and then determines the dual-T2 cutoff value of the saturation soft soil according to the difference of the T2 spectrum measured after the saturation soft soil is frozen and thawed.The method only needs simple freezing equipment and timing device, the instrument is common and has strong replaceability, and the operation is simple, so it has strong implementability in actual engineering, and provides a new idea for the determination of nuclear magnetic resonance T2 cutoff value.

Description

Technical Field

[0001] This invention relates to the field of underground construction, and in particular to a method for measuring the double T2 cutoff value of porous discontinuous structures. Background Technology

[0002] For saturated soft soil, the pores are filled with water, which can be classified into clay-bound water, capillary-bound water, and free water according to size. Clay-bound water refers to the bound water film tightly adhering to the surface of soil particles; it can also be called strongly bound water. It has no ability to dissolve salts and cannot transmit hydrostatic pressure; the corresponding pores are usually called clay-bound pores. Capillary-bound water is a bound water film formed tightly adhering to the outer periphery of the clay-bound water; it can also be called weakly bound water. It also cannot transmit hydrostatic pressure. When the soil contains a large amount of weakly bound water, the soil has a certain degree of plasticity; the corresponding pores are usually called capillary-bound pores. Free water refers to water existing outside the influence range of the electric field on the surface of soil particles. Its properties are the same as normal water; it can transmit hydrostatic pressure; the corresponding pores are usually called free pores. Soil pores contain different types and phases of water, among which clay-bound water, capillary-bound water, and free water are closely related to engineering properties. Different types of water have different effects on the engineering properties of soil. Therefore, determining the composition of different types of water in soil is crucial for the implementation of practical engineering projects.

[0003] After saturated soft soil undergoes freezing, the size and volume of small pores increase due to frost heave, while the size and volume of medium pores decrease simultaneously due to both frost heave and thaw settlement. This indicates that frost heave disrupts the soil structure, causing it to become looser. Water in the soil freezes rapidly initially, with most of the phase-change water freezing completely in the early stages. Within a given timeframe, the longer the freezing time, the greater the destructive effect of frost heave on soil porosity. For thawed soil at different freezing times, the peak value of small pores shows a significant non-linear correlation with the freezing time. The longer the freezing time, the lower the peak value of small pores, and the rate of decrease is initially rapid and then slows down.

[0004] The T2 transverse relaxation time measured by low-field nuclear magnetic resonance (NMR) can characterize the fluid distribution in soil. However, determining the T2 cutoff value (T2) from the T2 curve obtained by NMR is a complex issue. 2C Determining the distribution of free and bound water in soil using this information has always been a challenging research topic.

[0005] There are two methods to determine the T2 cutoff value. The first method is the "high-speed centrifugation method," which determines T by comparing the T2 relaxation time spectra before and after high-speed centrifugation. 2CAnother method is based on empirical judgment, known as the "half-amplitude method." Based on a summary of critical values ​​for various soil types, for single-peaked T2 relaxation time spectra primarily less than 10 ms, the midpoint of the amplitude of the right limb of the relaxation time curve is set as the critical value. Both methods can normally determine the critical value between bound water and free water.

[0006] The high-speed centrifugation method has strict requirements for laboratory equipment and experimental procedures to obtain accurate results. Meanwhile, the accuracy of the evaluation critical values ​​derived from the half-amplitude method is difficult to guarantee. Therefore, there is an urgent need for a simple and highly accurate method for determining the T0 of soft soil. 2C The method was used to determine the distribution of the three fluids in soft soil. Summary of the Invention

[0007] This invention provides a novel method for measuring the double T2 cutoff value of porous discontinuous structures, overcoming the shortcomings of existing technologies. This invention effectively improves the accuracy of determining the double T2 cutoff value of soft soil and has a positive impact on practical engineering applications.

[0008] The technical solution adopted in this invention is:

[0009] A method for measuring the dual T2 cutoff value of a porous discontinuous structure, characterized by comprising the following steps:

[0010] S1. Pre-treat the original soft soil sample;

[0011] S2. Saturate the pretreated sample.

[0012] S3. Use a method of increasing the freezing time with an equal time difference to freeze the saturated sample. Denote the number of times the freezing time is increased as i, and record the freezing time T for each increase. i ;

[0013] S4. After the samples were frozen for different durations, their T2 spectra were measured.

[0014] S5. Based on the peak value P of the main peak in the T2 spectrum measured in S4. Fi Draw P Fi With T i Changing curve (P) Fi -T i (curve), where P Fi T represents the peak value of the main peak in the T2 spectrum measured when the freezing time is increased for the i-th time. i Indicates the freeze time.

[0015] S6, P Fi Taking the derivative, we get P. Fi first derivative And draw With T iChanging curve ( curve);

[0016] S7, according to The physical meaning of the curve determines the inflection freezing time T of the saturated sample. M ;

[0017] S8. The saturated sample was frozen again using the method of increasing the freezing time with an equal time difference gradient. The longest freezing time was the transition freezing time T measured in S7. M And the NMR T2 spectra at different freezing times were measured;

[0018] S9. Calculate the double T2 cutoff value T based on the difference in the T2 spectrum obtained in S8. 21 and T 22 ;

[0019] S10, according to the T 21 and T 22 The T2 spectrum can be divided into clay-bound water, capillary-bound water, and free water.

[0020] Furthermore, in step S1, the sample is pretreated, specifically by preparing the original soft soil into a sample of suitable size.

[0021] Furthermore, in step S3, the saturated sample is frozen using the equal-time gradient time-increase method, specifically using the following control time equation:

[0022] T i = T0 + i * Δt; where T0 is the initial freeze duration, Δt is the gradient of freeze time increment, i is the number of increments, and T i This represents the freeze processing time after the i-th increment.

[0023] Furthermore, in step S5, P is drawn. Fi -T i The curve, specifically its mathematical model, is as follows:

[0024] Among them, P Fi For freezing as T i The peak value of the main peak in the T2 spectrum of the sample, T i , where is the freezing time, 'a' is a parameter related to the soil structure properties, and 'b' is related to the soil volume and freezing conditions.

[0025] Furthermore, in step S6, for P Fi Taking the derivative, we get P. Fi first derivative The specific formula used is as follows:

[0026] Where i > 1.

[0027] Furthermore, in step S7, according to The physical meaning of the curve determines the inflection freezing time T of the saturated sample. M Specifically: according to The relationship curve shows a decreasing trend, when The freeze time T corresponding to the value being 0 i The transition freeze time T M .

[0028] Furthermore, step S8 specifically includes the following steps:

[0029] After saturation treatment, the soft soil samples were grouped and labeled, then placed in a freezing chamber. The freezing time was increased in steps from small to large according to the labels, up to the transition freezing time T. M After the freezing test, the sample was taken out and allowed to thaw at a certain temperature for a period of time. After the sample was completely thawed, its T2 spectrum was measured. At this time, the T2 spectra of each group of soft soil samples after freezing and thawing showed obvious differences with different freezing times.

[0030] Furthermore, step S9 includes the following steps:

[0031] S901. Plot the T2 spectra of each group of soft soil samples on a single graph.

[0032] S902, to the left of the main peak in the T2 spectrum:

[0033] (1) The T2 curves obtained from samples in different groups first overlap and then separate. Thus, the left side of the main peak can be divided into an overlap stage and a dispersion stage. When an arbitrary T2 transverse relaxation time is selected in the dispersion stage, the amplitude of the T2 signal decreases with the increase of the freezing time.

[0034] (2) Draw a perpendicular line downwards at any point during the dispersion phase. The perpendicular line intersects all T2 curves. The intersection point is denoted as A. i (Q, f) i ), where: Q represents the T2 transverse relaxation time corresponding to the vertical line; f i Indicates the freeze time as T i The sample, with a T2 transverse relaxation time of Q, corresponds to the T2 signal amplitude.

[0035] (3) Find f i variance f 2 The specific formula is as follows:

[0036]

[0037]

[0038] in, f iThe average value; n is the freezing time that increases at a constant gradient from T0 to T. M The number of times the freeze duration increases.

[0039] (4) When f 2 When = 0.05, the corresponding T2 transverse relaxation time Q is T. 21

[0040] S903, to the right of the main peak in the T2 spectrum:

[0041] (1) The T2 curves measured from different groups of samples can be divided into two stages from left to right. The characteristic of stage one is that when an arbitrary T2 transverse relaxation time is selected, the amplitude of the corresponding T2 signal decreases as the sample freezing time increases. The characteristic of stage two is that when an arbitrary T2 transverse relaxation time is selected, the amplitude of the corresponding T2 signal increases as the sample freezing time increases.

[0042] (2) Draw a perpendicular line downwards at any position in stage two. The perpendicular line intersects all T2 curves. The intersection point is denoted as B. i (X, y) i ), where: X represents the T2 transverse relaxation time corresponding to the vertical line; y i Indicates the freeze time as T i The sample, with a T2 transverse relaxation time of X, corresponds to the T2 signal amplitude.

[0043] (3) Find y i variance y 2 The specific formula is as follows:

[0044]

[0045]

[0046] in, For y i The average value; n is the freezing time that increases at a constant gradient from T0 to T. M The number of times the freeze duration increases.

[0047] (4) When y 2 When the value is 0.05, the corresponding T2 transverse relaxation time X is T. 22

[0048] Furthermore, in step S10, according to the T 21 and T 22 The T2 spectrum is divided into clay-bound water, capillary-bound water, and free water. Specifically, in the T2 spectrum, T... 21 The left side is divided into clay-bound water; T 21 and T 22The portion between them is divided into capillary bound water; T 22 The right side is divided into free water.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] This method, based on the T2 spectrum measured after freezing saturated soft soil, first determines the transition freezing time, and then, based on the differences in T2 spectra measured after freeze-thaw cycles, determines the dual T2 cutoff values ​​for saturated soft soil. This method requires only simple freezing equipment and timing devices; the instruments are relatively common and readily replaceable, the operation is simple, and it is highly feasible in practical engineering, providing a pioneering new approach to determining the T2 cutoff value of nuclear magnetic resonance.

[0051] The T2 cutoff value measured by this method is a suitable method to distinguish the three water components in saturated soft soil. Compared with traditional methods, it has higher accuracy and fills the gap in the testing of cutoff values ​​for clay-bound water and capillary-bound water. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the T2 spectrum measured after the sample in the present invention was frozen.

[0053] Figure 2 In this invention Figure 1 The peak value P of the main peak of the T2 curve Fi With freezing time T i The relationship curve of change (P) Fi -T i curve);

[0054] Figure 3 P in this invention Fi first derivative With freezing time T i The changing relationship curve ( curve);

[0055] Figure 4 This is a schematic diagram of the T2 spectrum measured after the sample was frozen and thawed in this invention;

[0056] Figure 5 In this invention Figure 4 A schematic diagram showing a vertical line drawn to the left of the main peak of the T2 spectrum on the horizontal axis;

[0057] Figure 6 In this invention Figure 4 A schematic diagram showing a vertical line drawn to the left of the main peak of the T2 spectrum on the horizontal axis;

[0058] Figure 7 This is a schematic diagram of fluid distribution. Detailed Implementation

[0059] This method, based on the spectrum measured after freezing saturated soft soil, first determines the transition freezing time, and then, based on the spectral differences measured after freeze-thaw cycles, determines the dual cutoff values ​​for saturated soft soil. This method requires only simple freezing equipment and timing devices; the instruments are relatively common and easily replaceable, the operation is simple, and it is highly feasible in practical engineering, providing a pioneering new approach to determining nuclear magnetic resonance cutoff values. The cutoff values ​​measured by this method are suitable for distinguishing the three water components in saturated soft soil, offering higher accuracy compared to traditional methods, and filling the gap in the testing of cutoff values ​​for clay-bound water and capillary-bound water.

[0060] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0061] Example

[0062] A method for measuring the dual T2 cutoff value of a porous discontinuous structure is characterized by the following steps:

[0063] S1. Pre-treat the original soft soil sample; specifically, first use a ring cutter with a diameter of 50.46mm to take soil, then use a soil cutting knife to make the soil sample into a cross-sectional size of 38*38mm, and finally place the soil sample in a mold.

[0064] S2. Saturate the pretreated sample; specifically, saturate the pretreated sample using the back pressure saturation method, with the back pressure set to 12 kPa and the confining pressure set to 25 kPa. The back pressure saturation ends when the pore pressure coefficient B is greater than 0.95.

[0065] S3. Use a method of increasing the freezing time with an equal time difference to freeze the saturated sample. Denote the number of times the freezing time is increased as i, and record the freezing time T for each increase. i ;

[0066] When freezing saturated samples using the equal-time gradient increasing method, the following control time equation is employed:

[0067] T i =T0+i*Δt

[0068] Where T0 is the initial freeze duration, Δt is the freeze time increment gradient, i is the number of increments, and T i This represents the freeze processing time after the i-th increment.

[0069] In this embodiment, T0 is 0h, Δt is 2h, and T i The maximum value is 14h.

[0070] S4. After the samples have been frozen for different durations, their T2 spectra are taken out and measured immediately (e.g., Figure 1 Specifically, the T2 spectrum of the sample is measured immediately after the sample is carefully removed from the freezing box.

[0071] S5. Based on the peak value P of the main peak in the T2 spectrum measured in S4. Fi Draw P Fi With T i Changing curve (P) Fi -T i (curve), where P Fi T represents the peak value of the main peak in the T2 spectrum measured when the freezing time is increased for the i-th time. i Indicates the freeze time. (e.g.) Figure 2 )

[0072] P drawn Fi -T i The curve, specifically its mathematical model, is as follows:

[0073]

[0074] In the formula, P Fi For freezing as T i The peak value of the main peak in the T2 spectrum of the sample, T i , where is the freezing time, 'a' is a parameter related to the soil structure properties, and 'b' is related to the soil volume and freezing conditions.

[0075] In this example, after fitting, the soil sample values ​​are a = 7.455, b = 0.2562, and the variance of the fit is R0. 2 It is 0.979.

[0076] S6, P Fi Taking the derivative, we get P. Fi first derivative And draw With T i Changing curve ( (curve) (e.g.) Figure 3 );

[0077] The specific formula used is as follows:

[0078]

[0079] Where i > 1.

[0080] S7, by Figure 3 It can be seen that, The relationship curve shows a decreasing trend, according to The physical meaning of the curve, when The freeze time T corresponding to the value being 0 i The transition freeze time T MIn this embodiment, the measured freezing time T M =14h.

[0081] S8. The saturated sample was frozen again using the method of increasing the freezing time with an equal time difference gradient. The longest freezing time was the transition freezing time T measured in S7. M The NMR T2 spectra at different freezing times were measured, and the specific steps are as follows:

[0082] After saturation treatment, the soft soil samples were grouped and labeled, then placed in a freezing chamber. The freezing time was increased in steps from small to large according to the labels, up to the transition freezing time T. M After the freezing test, the sample was taken out and allowed to thaw at a certain temperature for a period of time. After the sample was completely thawed, its T2 spectrum was measured. At this time, the T2 spectra of each group of soft soil samples after freezing and thawing showed obvious differences with different freezing times.

[0083] In this embodiment, the numbers are 0 to 7, and the freezing times are 0h, 2h, 4h, 6h, 8h, 10h, 12h, and 14h in ascending order of the numbers. The melting temperature is 25℃ and the melting time is 24h.

[0084] S9. Calculate the double T2 cutoff value T based on the difference in the T2 spectrum obtained in S8. 21 and T 22 The specific steps are as follows:

[0085] S901. Plot the T2 spectra of each group of soft soil samples on a single graph (e.g., ...). Figure 4 );

[0086] S902, to the left of the main peak in the T2 spectrum:

[0087] (1) The T2 curves measured by samples from different groups first overlapped and then separated. Thus, the left side of the main peak can be divided into an overlap stage and a dispersion stage. When an arbitrary T2 transverse relaxation time is selected in the dispersion stage, the amplitude of the T2 signal decreases with the increase of the freezing time.

[0088] (2) Draw a perpendicular line downwards at any point during the dispersion phase. The perpendicular line intersects all T2 curves. The intersection point is denoted as A. i (Q, f) i ), where: Q represents the T2 transverse relaxation time corresponding to the vertical line; f i Indicates the freeze time as T i The sample, with a T2 transverse relaxation time of Q, corresponds to the T2 signal amplitude (e.g. Figure 5 ).

[0089] (3) Find f i variance f 2 The specific formula is as follows:

[0090]

[0091]

[0092] in, f i The average value; n is the freezing time that increases at a constant gradient from T0 to T. M The number of times the freeze duration increases.

[0093] (4) When f 2 When the value is 0.0005, the corresponding transverse relaxation time Q is T2. 21 .

[0094] In this embodiment, A0(0.317, 0.230), A1(0.317, 0.224), A2(0.317, 0.221), A3(0.317, 0.200), A4(0.317, 0.188), A5(0.317, 0.179), A6(0.317, 0.174), A7(0.317, 0.171), f 2 =0.0005, T 21 =0.317.

[0095] S903, to the right of the main peak in the T2 spectrum:

[0096] (1) The T2 curves measured from different groups of samples can be divided into two stages from left to right. The characteristic of stage one is that when an arbitrary T2 transverse relaxation time is selected, the amplitude of the corresponding T2 signal decreases as the sample freezing time increases. The characteristic of stage two is that when an arbitrary T2 transverse relaxation time is selected, the amplitude of the corresponding T2 signal increases as the sample freezing time increases.

[0097] (2) Draw a perpendicular line downwards at any position in stage two. The perpendicular line intersects all T2 curves. The intersection point is denoted as B. i (X, y) i ), where: X represents the T2 transverse relaxation time corresponding to the vertical line; y i Indicates the freeze time as T i The sample, with a T2 transverse relaxation time of X, corresponds to the T2 signal amplitude (e.g. Figure 6 ).

[0098] (3) Find y i variance y 2 The specific formula is as follows:

[0099]

[0100]

[0101] in, For y i The average value; n is the freezing time that increases at a constant gradient from T0 to T. M The number of times the freeze duration increases.

[0102] (4) When y 2 When the value is 0.05, the corresponding T2 transverse relaxation time X is T. 22 .

[0103] In this embodiment, B0(2.793, 0.170), B0(2.793, 0.174), B0(2.793, 0.185), B0(2.793, 0.191), B0(2.793, 0.200), B0(2.793, 0.216), B0(2.793, 0.220), B0(2.793, 0.216), B0(2.793, 0.228), f 2 =0.0005, T 21 =2.793.

[0104] S10, according to the T 21 and T 22 The T2 spectrum can be divided into clay-bound water, capillary-bound water, and free water.

[0105] Specifically, T 21 The left side is divided into clay-bound water; T 21 and T 22 The portion between them is divided into capillary bound water; T 22 The right side is divided into free water (e.g.) Figure 7 ).

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A porous discontinuous structure dual The cutoff value measurement method is characterized by, Includes the following steps: S1. Pre-treat the original soft soil sample; S2. Saturate the pretreated sample. S3. The saturated sample is frozen using a method that increases the freezing time using an equal-time gradient. The number of times the freezing time is increased is denoted as... Record the freeze time each time. ; S4. After the samples have been frozen for different durations, they are removed and immediately measured using nuclear magnetic resonance (NMR) technology. Spectrum; S5, based on the results obtained in S4 using nuclear magnetic resonance technology. The main peak value of the spectrum ,draw along with The changing curve is - Curve, in which, Indicates the first The measurement was obtained by increasing the freeze duration. Peak value of the main peak in the spectrum Indicates the freeze time; S6, regarding S5 Taking the derivative, we get first derivative and draw along with The changing curve is - curve; S7, according to S6 - The physical meaning of the curve, determining the inflection freezing time of the saturated sample. ; S8. The saturated sample was frozen again using the method of increasing the freezing time with an equal time difference gradient. The longest freezing time was the transition freezing time measured in S7. ， After freezing, the samples were removed and placed at a specific temperature to thaw for a period of time. After thawing, the properties of each sample were measured. Spectrum; S9, obtained from S8 Spectral differences for obtaining double Cutoff value and ; S10, as described in S9 and ,Will The spectrum is divided into clay-bound water, capillary-bound water, and free water.

2. A porous discontinuous structure double according to claim 1 The cutoff value measurement method is characterized by, In step S1, the sample is pretreated, including preparing a sample of appropriate size.

3. A porous discontinuous structure double according to claim 1 The cutoff value measurement method is characterized by, In step S3, the saturated sample is frozen using an equal-time gradient increasing method, specifically using the following control time equation: ； in, The initial freeze duration, Add a gradient to the freeze time. To increase the number of times, For the first Freeze processing time after each additional time.

4. A porous discontinuous structure dual according to claim 1 The cutoff value measurement method is characterized by, In step S5, the drawing - The curve, its specific mathematical model is as follows: ； In the formula, For freezing Sample Peak value of the main peak in the spectrum For the freeze time, For parameters related to soil structure properties, It is related to the soil volume and freezing conditions.

5. A porous discontinuous structure double according to claim 1 The cutoff value measurement method is characterized by, In step S6, for Taking the derivative, we get first derivative The specific formula used is as follows: ,in, >=1.

6. A porous discontinuous structure dual according to claim 1 The cutoff value measurement method is characterized by, In step S7, according to - The physical meaning of the curve, determining the inflection freezing time of the saturated sample. Specifically: according to - The relationship curve shows a decreasing trend, when Freeze time corresponding to a value of 0 Freeze time for transition .

7. A porous discontinuous structure double according to claim 1 The cutoff value measurement method is characterized by, Step S8 specifically includes the following steps: After saturation treatment, the soft soil samples were grouped and labeled, then placed in a freezing chamber. The freezing time was increased in steps from small to large according to the labels, up to the transition freezing time. After the freezing test, remove and measure. The spectrum shows that the soft soil samples in each group have undergone freezing treatment for different durations. The spectra will show obvious differences.

8. A porous discontinuous structure double according to claim 1 The cutoff value measurement method is characterized by, Step S9 includes the following steps: S901, The measurements of each group of soft soil samples The spectrum is drawn on a single graph; S902, in Left side of the main peak of the spectrum: (1) Measured from samples in different groups The curves first overlap and then separate, thus dividing the left side of the main peak into an overlap phase and a dispersion phase. An arbitrary selection is made during the dispersion phase. During the lateral relaxation time, The signal amplitude decreases as the freeze time increases; (2) Draw a perpendicular line downwards at any point during the dispersion phase. The perpendicular line intersects all... All curves intersect, and the intersection point is denoted as . ( , ),in: This indicates the vertical line corresponding to Lateral relaxation time; Indicates the freeze time is The sample, in Lateral relaxation time is Time corresponding Signal amplitude; (3) Find variance The specific formula is as follows: in, for The average value; Freeze time from The gradient increases to The number of times the freeze duration increases; (4) When When = 0.05, the corresponding Lateral relaxation time That is ; S903, in Right side of the main peak of the spectrum: (1) Measured from samples in different groups The curve is divided into two stages from left to right. The characteristic of stage one is that it involves selecting an arbitrary and specific... When the lateral relaxation time is, the corresponding The signal amplitude decreases as the sample freezing time increases; the characteristic of stage two is that it involves selecting arbitrarily determined... When the lateral relaxation time is, the corresponding The signal amplitude increases with increasing sample freezing time; (2) Draw a perpendicular line downwards from any position in stage two, and the perpendicular line intersects with all All curves intersect, and the intersection point is denoted as . ( , ),in: This indicates the vertical line corresponding to Lateral relaxation time; Indicates the freeze time is The sample, in Lateral relaxation time is Time corresponding Signal amplitude; (3) Find variance The specific formula is as follows: in, for The average value; Freeze time from The gradient increases to The number of times the freeze duration increases; (4) When When = 0.05, the corresponding Lateral relaxation time That is .

9. A porous discontinuous structure double according to claim 8 The cutoff value measurement method is characterized by, In step S10, according to the above and Will The spectrum is divided into clay-bound water, capillary-bound water, and free water, specifically, exist In the score, The left side is divided into clay-bound water; and The portion between them is divided into capillary bound water; The right side is divided into free water.

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