A method for determining water saturation in rock failure process under load

Abstract

The present invention discloses a method for determining the water saturation of a rock during a load-bearing failure process. The method uses fitting to obtain a functional relationship between any two of the three parameters of a rock specimen, namely strain, acoustic emission energy, and resistivity, and the initial water saturation. For a rock specimen with unknown water saturation, the method obtains strain, acoustic emission energy, and resistivity data from a multivariate information collaborative monitoring experiment and substitutes these data into the functional relationship to invert the initial water saturation of the rock. The initial water saturation and the resistivity measured at any moment during the multivariate information collaborative monitoring experiment are substituted into the rock water saturation inversion formula to obtain the water saturation at any moment during the load-bearing failure process of the rock. Using the technical solution of the embodiments of the present invention, rapid quantitative inversion of the water saturation of the rock during a load-bearing failure process can be performed using laboratory-monitored deformation, acoustic emission energy, and resistivity data.

Description

Technical Field

[0001] The present invention belongs to the technical field of rock physics, and in particular relates to a method for determining water saturation in a rock failure process under load. Background Art

[0002] The destruction of water-blocking surrounding rock and groundwater migration caused by mining are accompanied by changes in multiple physical field information, including deformation, energy, and resistivity. The physical field response characteristics of the surrounding rock can be used to identify its damage and water content. For example, rock deformation can reflect its damage state, and the extent of water-conducting fractures can be effectively identified based on the deformation and differences in surrounding rock in different monitoring areas. Rock fracture and fracture development are accompanied by the release of large amounts of energy. By capturing the energy signals released by surrounding rock fractures, three-dimensional, real-time monitoring of the development of water-conducting channels can be achieved. Rock resistivity information can sensitively reflect its damage and water content, and water-conducting channels and the extent of water seepage migration can be identified based on the surrounding rock resistivity.

[0003] Currently, relying on a single physical field information source is insufficient to fully reflect the dynamic changes in surrounding rock failure and water content during mining. For example, deformation alone cannot accurately reflect the water content within the fractured rock mass. Acoustic emission energy signals can determine the extent of water channels, but they cannot determine the conduction and diffusion of groundwater within these channels. Surrounding rock resistivity can provide real-time information on rock water content, but its detection results are significantly affected by the environment and have low resolution, necessitating the integration of other geophysical information to improve the accuracy of resistivity data interpretation. During the mining process, coupled responses exist between the multi-physical field information of the surrounding rock. For example, upon reaching a deformation threshold, the surrounding rock will fail and release a large amount of energy, while its resistivity will increase significantly. This resistivity will then decrease significantly when the surrounding rock fractures are filled with water. Comprehensively considering the multi-dimensional physical field information generated by surrounding rock failure and water diffusion and migration can more comprehensively reflect the development of water channels and groundwater migration during mining. Existing literature lacks methods for inverting water saturation during rock failure under load by combining multivariate information. Furthermore, there are no reports on how to accurately predict water saturation at a specific moment in rock failure under load using real-time deformation, acoustic emission energy, and resistivity data. Therefore, it is necessary to establish a scientific and reasonable inversion method for water saturation during rock failure under load. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for determining the water saturation of rock during load failure, which can use the deformation, acoustic emission energy and resistivity data monitored in the laboratory to quickly and quantitatively invert the water saturation of the rock during load failure.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for determining water saturation during a rock failure process under load comprises the following steps:

[0007] Step S1, respectively prepare the initial water saturation S w1 The experimental group and the initial water saturation is S w2 The validation group rock specimens;

[0008] Step S2: Collect and record the strain ε and acoustic emission energy k of the rock specimen during the entire uniaxial compression test. U , resistivity k ρ Real-time data;

[0009] Step S3: Obtain strain ε and acoustic emission energy k by fitting U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between

[0010] Step S4: For rock samples with unknown water saturation, obtain multivariate information to collaboratively monitor strain ε and acoustic emission energy k during the experiment. U , resistivity k ρ The initial water saturation S of the rock can be obtained by substituting the data into the functional relationship. w ;

[0011] Step S5: Initial water saturation S w The resistivity kρ' measured at any time during the multi-information collaborative monitoring experiment is substituted into the rock water saturation inversion formula to obtain the water saturation S at any time during the rock load failure process. w '.

[0012] As a preferred method, in step S2, a multi-information collaborative monitoring experiment of the rock loading process is carried out on the rock specimens of the experimental group, and the strain amount ε and acoustic emission energy k of the rock specimens during the whole process of the uniaxial compression test are continuously collected and recorded by strain gauges, acoustic emission probes and digital bridges. U , resistivity k ρ Real-time data.

[0013] As a preferred step S3, the strain ε and acoustic emission energy k obtained by fitting U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between them is as follows:

[0014] ① Strain ε, acoustic emission energy k U , initial water saturation S w1 The following equation is satisfied between the three:

[0015]

[0016] Among them, e is a constant coefficient related to lithology, and f is the water saturation influence coefficient;

[0017] ②Strain ε, resistivity k ρ , initial water saturation S w1 The following equation is satisfied between the three:

[0018] k ρ =(j1+j2·S w1 0.7 )(k1+k2·S w1 -ε) 4 +l1+l2·S w1 1.5 (2)

[0019] Among them, j1, k1, and l1 are constant coefficients related to lithology; j2, k2, and l2 are water saturation influence coefficients;

[0020] ③Acoustic emission energy k U , resistivity k ρ , initial water saturation S w1 The following equation is satisfied between the three:

[0021]

[0022] Among them: a1, b1, c1, d1 are constant coefficients related to lithology; a2, b2, c2, d2 are water saturation influence coefficients.

[0023] As a preferred step S5, the water saturation S at any time during the rock failure process is w ', comprising the following steps:

[0024] Step 5.1: Collect strain ε and acoustic emission energy k during the experiment through the rock load multi-information collaborative monitoring experiment U , resistivity k ρ data;

[0025] Step 5.2: Substitute the above data into the functional relationship to invert the initial water saturation S of the rock. w ;

[0026] Step 5.3: Initial rock water saturation S w , initial resistivity k ρ , Substitute the resistivity kρ' measured at any moment into the following formula to obtain the rock water saturation S corresponding to that moment: w ',

[0027]

[0028] As a preference, in step S1, rock specimens with different water saturations are prepared by natural immersion method, and the initial water saturation S of each specimen is calculated by calculating the difference in mass of the rock specimens before and after immersion. w1 and S w2 .

[0029] This method comprehensively considers multi-dimensional physical field information such as deformation, acoustic emission energy, and resistivity generated during rock failure under load, resolving the technical challenges of traditional inversion methods that rely on a single resistivity inversion method to accurately predict water saturation during rock failure and are significantly affected by external factors. This method boasts simple operation, comprehensive indicators, and strong applicability. Furthermore, this method can be expanded to real-time monitoring, inversion, and early warning of the development of water-conducting fractures in overlying strata and groundwater migration in aquifers during excavation in coal mines, subways, and tunnels. This addresses the technical challenges of difficult real-time water saturation predictions for surrounding rock during mining, limited available data, and incomplete evaluation indicators. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0031] Figure 1 This is a flow chart of a method for determining water saturation in a rock failure process under load according to an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Example 1:

[0035] like Figure 1 As shown, an embodiment of the present invention provides a method for determining water saturation in a rock failure process under load, comprising the following steps:

[0036] Step S1: Prepare the initial water saturation S w1 and S w2The rock specimens were prepared with the initial water saturation as S w1 The rock specimens are defined as the experimental group, and the initial water saturation is S w2 The rock specimens with unknown initial water saturation are defined as the validation group; in addition, a group of rock specimens with unknown initial water saturation are prepared;

[0037] Step S2: Conduct a multi-information collaborative monitoring experiment on the rock loading process of the experimental group of rock specimens. Through strain gauges, acoustic emission probes and digital bridges, continuously collect and record the strain ε and acoustic emission energy k of the rock specimens during the entire uniaxial compression test. U , resistivity k ρ Real-time data;

[0038] Step S3: After the experiment is over, the “strain ε-energy k” of the rock specimens during the multivariate information collaborative monitoring experiment is plotted. U ”, “Strain ε-resistivity k ρ ”, “Energy k U -Resistivity k ρ "The curve between the strain ε and the acoustic emission energy k is obtained by fitting. U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between

[0039] Step S4: The strain ε and acoustic emission energy k monitored during the multivariate information collaborative monitoring experiment of the rock specimens in the verification group are U , resistivity k ρ Substituting the above established functional relationship, the initial water saturation S of the rock specimens in the verification group can be obtained by inversion: w2 ', and with the recorded S w2 Conduct comparative verification;

[0040] Step S5: For rock samples with unknown water saturation, the strain ε and acoustic emission energy k are monitored in the experimental process by acquiring multivariate information. U , resistivity k ρ The data can be substituted into the functional relationship established in step S3 to obtain the initial water saturation S of the rock. w ; The initial water saturation S w The resistivity kρ' measured at any time during the multi-information collaborative monitoring experiment is substituted into the rock water saturation inversion formula to obtain the water saturation S at any time during the rock load failure process. w '.

[0041] As an implementation method of the present invention, the rock selected in step S1 is required to be uniform in texture, without obvious internal cracks, and all taken from the same stone slab. The above rock is processed into a standard cylindrical specimen of 50mm×100mm according to the international rock mechanics testing standard. The rock specimens with different water saturations are prepared by natural immersion method, and the initial water saturation S of each sample is calculated by calculating the difference in mass of the rock specimen before and after immersion. w1 and S w2 , and then immediately carried out the multi-information collaborative monitoring experiment of the rock loading process.

[0042] Furthermore, the multi-information collaborative monitoring experiment of the rock loading process includes the following steps:

[0043] Step 1.1: First, place a rigid Teflon insulating plate in the center of the lower loading plate. Then, place a conductive copper sheet in the middle of the insulating plate. Then, place the rock sample in the center of the lower conductive copper sheet. Then, place another conductive copper sheet on the top surface of the rock sample. Finally, gently place another rigid Teflon insulating plate on top of the upper conductive copper sheet.

[0044] Step 1.2: Install the acoustic emission monitoring system and the AE sensor probe. Set the AE threshold voltage to 100mV and the acquisition frequency to 3MHz.

[0045] Step 1.3: Turn on the static resistance strain gauge host, measure and confirm that the open-circuit resistance and short-circuit resistance of the resistivity system are normal, connect the monitoring electrodes, and set the sampling interval to 0.5s;

[0046] Step 1.4: Stress loading system setup: Slowly lower the loading plate on the universal testing machine until it lightly contacts the insulating plate at the top of the rock sample. Then, select displacement loading control to apply the load, setting the loading rate to 0.2 mm / min. Finally, enter the rock sample number and parameters into the main machine.

[0047] Step 1.5: Simultaneously start the strain monitoring system, acoustic emission monitoring system and resistivity monitoring system to monitor the water saturation S in real time. w1 The “ε-k U -k ρ "Multi-parameter response characteristics, until the loaded rock sample is completely destroyed. After the experiment, a new round of rock sample testing will begin.

[0048] After all experiments were completed, the strain ε and acoustic emission energy k were obtained by fitting. U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between

[0049] As an implementation of the embodiment of the present invention, in step S3, the strain ε and acoustic emission energy k obtained by fitting are U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between them is as follows:

[0050] ① Strain ε, acoustic emission energy k U , initial water saturation S w1 The following equation is satisfied between the three:

[0051]

[0052] Among them, e is a constant coefficient related to lithology, and f is the water saturation influence coefficient, which are taken as 0.547 and 0.0836 respectively;

[0053] ②Strain ε, resistivity k ρ , initial water saturation S w1 The following equation is satisfied between the three:

[0054] k ρ =(j1+j2·S w1 0.7 )(k1+k2·S w1 -ε) 4 +l1+l2·S w1 1.5 (2)

[0055] Among them: j1, k1, l1 are constant coefficients related to lithology, which are taken as 0.129, 1.195, and 0.719 respectively; j2, k2, and l2 are water saturation influence coefficients, which are taken as -0.18, 0.409, and 0.598 respectively;

[0056] ③Acoustic emission energy k U , resistivity k ρ , initial water saturation S w1 The following equation is satisfied between the three:

[0057]

[0058] Among them: a1, b1, c1, and d1 are constant coefficients related to lithology, which are taken as 0.129, 1.195, 0.547, and 0.719 respectively; a2, b2, c2, and d2 are water saturation influence coefficients, which are taken as -0.18, 0.409, -0.0836, and 0.598 respectively.

[0059] As an implementation method of the embodiment of the present invention, in step S4, the strain ε and acoustic emission energy k monitored during the multi-information collaborative monitoring experiment of the rock specimens of the verification group are U , resistivity k ρ Substituting the above established functional relationships (1), (2), and (3) in turn, the inverse prediction value S of the initial water saturation of the verification group rock specimen can be obtained. w2 ', and compared with the actual measured initial rock saturation S w2 Comparison is made to verify the applicability of functional relationships (1), (2), and (3). After determining the applicability of the functional relationship, the strain ε and acoustic emission energy k of the rock specimen with unknown water saturation are used in the collaborative monitoring experiment. U , resistivity k ρ The initial water saturation of the rock S can be obtained by w .

[0060] As an implementation method of the present invention, in step S5, the water saturation S at any time during the rock failure process is w ', the calculation process includes the following steps:

[0061] Step 5.1: Collect strain ε and acoustic emission energy k during the experiment through the rock load multi-information collaborative monitoring experiment U , resistivity k ρ data;

[0062] Step 5.2: Substitute the above data into the functional relationships (1), (2), and (3) established by the above method to invert and obtain the initial water saturation S of the rock. w ;

[0063] Step 5.3: Initial rock water saturation S w , initial resistivity k ρ , Substitute the resistivity kρ' measured at any moment into the following formula to obtain the rock water saturation S corresponding to that moment: w ';

[0064]

[0065] The present invention prepares the initial water saturation S w1 The experimental group and the initial water saturation is S w2 The rock specimens of the verification group were used to carry out the multi-information collaborative monitoring experiment of the rock loading process on the rock specimens of the experimental group. The strain amount ε and acoustic emission energy k of the rock specimens during the whole process of the uniaxial compression test were continuously collected and recorded by strain gauges, acoustic emission probes and digital bridges. U , resistivity k ρ Real-time data; strain ε and acoustic emission energy k are obtained by fittingU , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between them is verified by the rock experiment of the verification group. For the rock sample with unknown water saturation, the strain ε and acoustic emission energy k are monitored in the experimental process by obtaining multivariate information. U , resistivity k ρ By substituting the data into the functional relationship established by the above method, the initial water saturation S of the rock can be obtained by inversion. w ; The initial water saturation S w The resistivity kρ' measured at any time during the multi-information collaborative monitoring experiment is substituted into the rock water saturation inversion formula to obtain the water saturation S at any time during the rock load failure process. w The present invention makes up for the fact that traditional methods rely on single physical field information and are unable to fully reflect the dynamic changes of water saturation during the rock loading and failure process. It can accurately and truly perform real-time inversion prediction of water saturation at any moment in the rock loading and failure process.

[0066] Example 2:

[0067] like Figure 1 As shown, an embodiment of the present invention provides a method for determining water saturation in a rock failure process under load, comprising the following steps:

[0068] Step S1: Taking rock as an example, prepare the initial water saturation S w1 and S w2 The rock specimens were prepared with the initial water saturation as S w1 The rock specimens are defined as the experimental group, and the initial water saturation is S w2 The rock specimens with unknown initial water saturation are defined as the validation group; in addition, a group of rock specimens with unknown initial water saturation are prepared;

[0069] Step S2: Conduct a multi-information collaborative monitoring experiment on the rock loading process of the experimental group of rock specimens. Through strain gauges, acoustic emission probes and digital bridges, continuously collect and record the strain ε and acoustic emission energy k of the rock specimens during the entire uniaxial compression test. U , resistivity k ρ Real-time data;

[0070] Step S3: After the experiment is over, the “strain ε-energy k” of the rock specimens during the multivariate information collaborative monitoring experiment is plotted. U ”, “Strain ε-resistivity k ρ ”, “Energy k U -Resistivity k ρ "The curve between the strain ε and the acoustic emission energy k is obtained by fitting. U, resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between

[0071] Step S4: The strain ε and acoustic emission energy k monitored during the multivariate information collaborative monitoring experiment of the rock specimens in the verification group are U , resistivity k ρ Substituting the above established functional relationship, the initial water saturation S of the rock specimens in the verification group can be obtained by inversion: w2 ', and with the recorded S w2 Conduct comparative verification;

[0072] Step S5: For rock samples with unknown water saturation, the strain ε and acoustic emission energy k are monitored in the experimental process by acquiring multivariate information. U , resistivity k ρ The data can be substituted into the functional relationship established in step S3 to obtain the initial water saturation S of the rock. w ; The initial water saturation S w The resistivity kρ' measured at any time during the multi-information collaborative monitoring experiment is substituted into the rock water saturation inversion formula to obtain the water saturation S at any time during the rock load failure process. w '.

[0073] Here, laboratory experiments are taken as an example to verify the method for determining water saturation in the rock load failure process based on multivariate information inversion.

[0074] For the rocks used in the inversion experiment, five specimens with different water saturations were prepared. A total of five specimens were prepared in the experiment. The parameters such as the water content, dry resistivity, and initial resistivity after immersion in water are shown in Table 1.

[0075] Table 1

[0076]

[0077] The preparation process of specimens with different water saturations is as follows:

[0078] ① Determination of natural moisture content: First, record the dimensions and mass of each specimen in its natural state. Maintain the specimen at 105°C for 24 hours, then remove it. Test and record the mass every two hours until the mass stabilizes. After cooling, measure and record the final mass of the rock sample. Calculate the difference between the mass of the specimen in its natural state and the mass of the dried rock sample to determine the natural moisture content of each rock sample.

[0079] ② Preparation of rock samples with different water saturations: The natural immersion method was used to prepare rock samples with different water saturations. First, the water saturation gradient of the rock designed in the experiment was determined to be: 0%, 25%, 50%, 75%, and 100%. The corresponding mass of the rock with different water saturations was calculated. When the mass of the specimen after immersion was close to the target value, the measurement time interval was shortened until each rock sample reached the target mass.

[0080] ③ Test rock sample sealing: For the prepared rock samples with corresponding water saturation, seal the rock samples with plastic wrap to prevent water evaporation from interfering with the results of physical and mechanical experiments, and conduct the experiment as soon as possible.

[0081] Experimental process of multi-information collaborative monitoring of rock loading process:

[0082] (1) Placement of rock sample: First, place a rigid Teflon insulating plate in the central area of ​​the lower loading disk, then place a conductive copper sheet in the middle of the insulating plate, then place the rock sample with the AE sensor bonded to the center of the lower conductive copper sheet, then place another conductive copper sheet on the top surface of the rock sample, and finally gently place another rigid Teflon insulating plate on top of the upper conductive copper sheet.

[0083] (2) Strain monitoring system settings: Turn on the static resistance strain gauge host, connect the strain gauge to the strain gauge, and set the strain gauge parameters.

[0084] (3) Acoustic Emission Monitoring System Setup: Install the AE sensor probes connected to the acoustic emission monitoring system in sequence. Set the AE threshold voltage to 100mV and the acquisition frequency to 3MHz.

[0085] (4) Resistivity monitoring system settings: Measure and confirm that the open-circuit resistance and short-circuit resistance of the resistivity system are normal, then connect the monitoring electrodes with a sampling interval of 0.5s.

[0086] (5) Stress loading system setup: Slowly lower the loading plate on the universal testing machine until it lightly contacts the insulating plate at the top of the rock sample. Then, select displacement loading control to apply the load, and set the loading rate to 0.2 mm / min. Finally, enter the rock sample number and parameters into the main machine.

[0087] (6) “ε-k U -k ρ "Multi-parameter monitoring: Simultaneously start the strain monitoring system, acoustic emission monitoring system and resistivity monitoring system to synchronously monitor the "ε-k" of rock samples with different water saturations during uniaxial loading. U -k ρ "Multi-parameter response characteristics until the loaded rock sample is completely destroyed.

[0088] The strain (ε) and released energy (k) in the rock load failure process were obtained by the rock load multi-information collaborative monitoring experiment. U ), resistivity (k ρ ) data for calculation and inversion; substitute them into the following formulas in sequence, and the results of the rock water content state inversion example are shown in Table 2.

[0089]

[0090] k ρ =(j1+j2·S w1 0.7 )(k1+k2·S w1 -ε) 4 +l1+l2·S w1 1.5 (2)

[0091]

[0092] It can be seen that the rock S of each case obtained by inversion method is w The overall error is small compared to the actual value, all below 10%. The inversion error of the rock examples is 2.96% to 8.34%. This shows that the proposed rock water content inversion method is accurate and reliable. For rocks with unknown water saturation, the initial water content and the real-time water content state S during the loading process can be obtained by repeating the above steps during the rock loading process. w .

[0093] In summary, the quantitative inversion method of rock water content proposed in this invention can be used to invert the "ε-U-ρ" multivariate information data of the rock to obtain the initial water content state S of the rock. w0 and the real-time water content S during the loading process w , to accurately grasp the water content of the entire process of rock deformation and destruction under load,

[0094] Table 2

[0095]

[0096] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A method for determining water saturation during rock failure under load, characterized in that: The following steps are involved: Step S1, respectively prepare the initial water saturation S w1 The experimental group and the initial water saturation is S w2 The validation group rock specimens; Step S2: Collect and record the strain ε and acoustic emission energy k of the rock specimen during the entire uniaxial compression test. U , resistivity k ρ Real-time data; Step S3: Obtain strain ε and acoustic emission energy k by fitting U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between Step S4: For rock samples with unknown water saturation, obtain multivariate information to collaboratively monitor strain ε and acoustic emission energy k during the experiment. U , resistivity k ρ The initial water saturation S of the rock can be obtained by substituting the data into the functional relationship. w ; Step S5: Initial water saturation S w The resistivity kρ' measured at any time during the multi-information collaborative monitoring experiment is substituted into the rock water saturation inversion formula to obtain the water saturation S at any time during the rock load failure process. w '; In step S2, a multi-information collaborative monitoring experiment of the rock loading process is carried out on the rock specimens of the experimental group. The strain amount ε and acoustic emission energy k of the rock specimens during the whole process of the uniaxial compression test are continuously collected and recorded by strain gauges, acoustic emission probes and digital bridges. U , resistivity k ρ Real-time data; In step S3, the strain ε and acoustic emission energy k obtained by fitting U , resistivity k ρ Any two of the three parameters and the initial water saturation S w1 The functional relationship between them is as follows: ① Strain ε, acoustic emission energy k U , initial water saturation S w1 The following equation is satisfied between the three: Among them, e is a constant coefficient related to lithology, and f is the water saturation influence coefficient; ②Strain ε, resistivity k ρ , initial water saturation S w1 The following equation is satisfied between the three: k ρ =(j1+j2·S w1 0.7 )(k1+k2·S w1 -ε) 4 +l1+l2·S w1 1.5 (2) Among them, j1, k1, and l1 are constant coefficients related to lithology; j2, k2, and l2 are water saturation influence coefficients; ③Acoustic emission energy k U , resistivity k ρ , initial water saturation S w1 The following equation is satisfied between the three: Among them: a1, b1, c1, d1 are constant coefficients related to lithology; a2, b2, c2, d2 are water saturation influence coefficients.

2. The method for determining water saturation in a rock failure process under load according to claim 1, wherein: In step S5, the water saturation S at any time during the rock failure process is w ', comprising the following steps: Step 5.1: Collect strain ε and acoustic emission energy k during the experiment through the rock load multi-information collaborative monitoring experiment U , resistivity k ρ data; Step 5.2: Substitute the above data into the functional relationship to invert the initial water saturation S of the rock. w ; Step 5.3: Initial rock water saturation S w , initial resistivity k ρ , Substitute the resistivity kρ' measured at any moment into the following formula to obtain the rock water saturation S corresponding to that moment: w ', 3. The method for determining water saturation in a rock failure process under load according to claim 2, wherein: In step S1, rock specimens with different water saturations are prepared by natural immersion method, and the initial water saturation S of each specimen is calculated by calculating the difference in mass of the rock specimens before and after immersion. w1 and S w2 .

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