Rock mass permeability coefficient in-situ testing method and device based on directional holes

Abstract

The invention belongs to the technical field of hydrogeological tests of engineering geological investigation, and particularly relates to a rock mass permeability coefficient in-situ testing device and method based on directional holes, and the method comprises the following steps: plugging a test section; acquiring pressure change data and flow information of the current test section in the drainage test process; acquiring pressure change data of the current test section after the water pressure is stable, and calculating underground water head height information above the test section in a stable pressure state; the drainage flow is adjusted to a preset flow value, and pressure change data and flow information of the test section in the drainage test process are obtained; calculating the height of an underground water head above the test section under the specific flow according to the pressure change data; the water level drop value of the underground water level in unit time is calculated, and a relation curve between the drainage test flow and the water level drop is drawn; and acquiring water pressure recovery process data. Therefore, the problem that parameters such as the in-situ permeability coefficient of the current rock mass are difficult to test and obtain is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering geological survey and hydrogeological test, and particularly relates to an in-situ testing method for rock mass permeability coefficient based on a directional hole and an in-situ testing device for rock mass permeability coefficient using the method. Background Art

[0002] At present, water pressure test is generally used to obtain the permeability parameters of rock mass in water conservancy and hydropower projects. The water pressure test can obtain the water permeability of rock mass through test pressure (P) and pressure flow (Q), and convert the water permeability into the permeability coefficient of rock mass, which is used in the calculation of water inflow for groundwater disaster prevention and control. The water permeability obtained by water pressure test reflects the permeability of rock mass near the borehole, which usually cannot represent the permeability of the entire aquifer.

[0003] The pumping test can obtain the hydrogeological parameters of aquifers over a large area. However, due to the influence of the borehole diameter, high-power pumps cannot be placed therein, making it difficult to conduct pumping tests.

[0004] Therefore, in view of the current problems of inaccurate rock permeability parameter test results and high test difficulty, a more suitable technical solution needs to be provided to solve the current technical problems. Summary of the invention

[0005] The purpose of the present invention is to provide a device for in-situ testing of rock mass permeability coefficient based on directional holes and a method for in-situ testing of rock mass permeability coefficient using the device, which can solve the problems of inaccurate test results of current rock mass permeability parameters and high test difficulty.

[0006] In order to achieve the above object, the present invention provides an in-situ testing device for rock mass permeability coefficient based on directional holes, comprising the following steps:

[0007] S100: block the directional hole and determine the test section;

[0008] S200: using a flow controller to change the water discharge flow rate, and obtaining pressure change data and flow information of the current test section during the water discharge test;

[0009] S300: Turn off the flow controller, obtain the pressure change data of the current test section after the water pressure is stabilized, and calculate the current groundwater head height information above the test section under the stable pressure state according to the pressure change data;

[0010] S400: Turn on the flow controller, adjust the water discharge flow to a preset flow value, and obtain the pressure change data and flow information of the current test section during the water discharge test;

[0011] S500: calculating the current groundwater head height above the test section at a specific flow rate based on the pressure change data and the pressure change data;

[0012] S600: obtaining the groundwater head height information change above the test section calculated based on the water pressure data under different flow conditions, obtaining the groundwater level drop value per unit time, and drawing a relationship curve between the water release test flow and the water level drop;

[0013] S700: After the water discharge flow is stable for a period of time, the flow controller is turned off to obtain the water pressure recovery process data.

[0014] In a possible design, the calculation formula for the groundwater level drop s' per unit time is:

[0015]

[0016] Where, Q-discharge flow, m 3 / d;

[0017] s-water level drawdown, m;

[0018] T-hydraulic conductivity, m 2 / d;

[0019] t-experimental duration, d;

[0020] t'-time for water level to recover, d;

[0021] The permeability coefficient K = T / M, M is the thickness of the aquifer.

[0022] In a possible design, a working tube is inserted into the directional hole, and a flower tube with a leakage hole is provided on the working tube; both ends of the flower tube are respectively sealedly connected to the directional hole; and the flow controller is arranged on the working tube.

[0023] In a possible design, pneumatic plugs are respectively provided at both ends of the flower tube to block the directional holes; wherein two groups of pneumatic plugs are arranged at intervals and the distance between the two forms the test section.

[0024] In a possible design, two groups of pneumatic embolisms are connected via a high-pressure air pipe, which extends to the outside of the directional hole and is connected to an air source; an embolism pressure gauge is provided on the high-pressure air pipe.

[0025] In a possible design, the working tube is provided with an instantaneous flow meter, an instantaneous pressure gauge and a pressure sensor;

[0026] The flow controller is arranged in the area where the working tube is located outside the directional hole; the instantaneous flow meter is arranged in the area where the working tube is located outside the directional hole; the instantaneous pressure meter is arranged between the flow controller and the instantaneous flow meter; the pressure sensor is arranged at the front end of the flower tube;

[0027] Among them, the instantaneous flow meter, the instantaneous pressure gauge and the pressure sensor are all communicatively connected to the control terminal, and the control terminal is used to calculate the hydraulic conductivity and permeability coefficient of the rock mass in the test section according to the flow change data and the pressure change data.

[0028] In one possible design, the calculation formula for the hydraulic conductivity and permeability is: K = T / M,

[0029] Where, T-hydraulic conductivity, m 2 / d; M is the thickness of the aquifer.

[0030] In a possible design, the rock mass permeability coefficient in-situ testing device is used for the rock mass permeability coefficient in-situ testing method according to any one of claims 1 to 7, and the rock mass permeability coefficient in-situ testing device comprises: a working pipe, a pneumatic plug and a high-pressure air pipe;

[0031] The working tube is provided with a flower tube with a leak hole; both ends of the flower tube are provided with pneumatic plugs for blocking the directional holes; the two pneumatic plugs are connected through a high-pressure air pipe, and the pneumatic plugs are connected to the air source through the high-pressure air pipe;

[0032] Along the flow direction of the liquid, the working tube is provided with a flow controller, an instantaneous pressure gauge, an instantaneous flow meter and a pressure sensor in sequence, wherein only the pressure sensor is provided in the area of ​​the working tube located in the directional hole;

[0033] The instantaneous pressure meter, instantaneous flow meter and pressure sensor are all communicatively connected to the control terminal.

[0034] By recording the water pressure data of the test section in real time through the pressure sensor, the change of the groundwater level above the borehole can be obtained, which helps to reflect the water level drop caused by water release. The use of flow controllers and instantaneous flow meters allows real-time control and recording of the size of the water release flow, which is crucial for analyzing the changes in groundwater levels under different water release flows.

[0035] The control terminal adopts the water level recovery calculation method of the constant flow pumping test, which can reduce the impact of unstable flow on the calculation results and improve the calculation efficiency and accuracy. Under different water discharge flow conditions, the water pressure changes recorded by the flow controller can be used to calculate the hydraulic conductivity (T) and permeability (K), thereby obtaining a large amount of data, which helps to obtain the permeability parameters of the rock mass in the test section more accurately.

[0036] Through repeated tests, the differentiated characteristics of rock permeability along the borehole can be reflected, which is very useful for evaluating the segmented water inflow of tunnels (holes). Compared with the traditional vertical borehole water release test, the horizontal directional drilling test records the water pressure changes through the test section isolation and storage water pressure sensor, avoiding the need for water level observation holes, thereby reducing the test cost. This method can be carried out under different geological and hydrological conditions and has good environmental adaptability. All measuring equipment is connected to the control terminal for communication, realizing integrated data management and real-time monitoring. By accurately controlling the water release flow and real-time monitoring of water level changes, the risks that may arise during the test can be better managed. The large amount of accurate data obtained provides a scientific basis for hydrogeological analysis and tunnel (hole) water inflow evaluation, which helps to make more accurate decisions. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A schematic structural diagram of an in-situ testing device for rock mass permeability coefficient based on directional holes provided by the present invention in one embodiment;

[0039] Figure 2 This is the curve of the test section changing with time at different flow rates during the directional hole water discharge test;

[0040] Figure 3 This is a diagram showing the change in groundwater level before and after the directional hole water release test of the present invention.

[0041] Figure 4 It is the fitting diagram of the measured curve of the directional hole water discharge test and the standard curve;

[0042] In the above drawings: 1-rock mass, 2-directional hole, 3-working pipe, 4-flowered pipe, 51-air pressure embolism, 52-high pressure air pipe, 53-embolism pressure gauge, 61-instantaneous pressure gauge, 62-instantaneous flow meter, 63-storage pressure sensor, 64-flow controller, 7-control terminal. DETAILED DESCRIPTION

[0043] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that although the description of these embodiments is used to help understand the present invention, it does not constitute a limitation of the present invention.

[0044] The specific structural and functional details disclosed herein are only for describing exemplary embodiments of the present invention. However, the present invention can be embodied in many alternative forms and should not be construed as limited to the embodiments set forth herein.

[0045] According to the first aspect of the present disclosure, the present invention provides an in-situ test method for the permeability coefficient of a rock mass 1 based on a directional hole 2, referring to Figures 1 to 4 As shown, the method uses the in-situ test device for permeability of rock mass 1 described in the second aspect to conduct a water release test on the test section. The water conductivity (T), permeability (K) and other parameters of the aquifer in the test section are calculated by combining the data recorded by the instantaneous flow meter 62, the instantaneous barometer and the in-hole storage pressure sensor 63 with the size of the horizontal directional drilling hole to obtain the permeability of the aquifer traversed by the tunnel (hole), which is used in the evaluation of the water inflow for the prevention and control of groundwater disasters in the tunnel (hole).

[0046] See also Figures 1 to 4 As shown, the invention proposes an in-situ test method for the permeability coefficient of a rock mass 1 based on a directional hole 2, comprising the following steps: S100: determining and blocking a test section; S200: using a flow controller 64 to change the water discharge flow rate, and obtaining pressure change data and flow change data of the current test section during the water discharge test; S300: closing the flow controller 64, obtaining pressure change data of the current test section after the water pressure is stabilized, and calculating the current groundwater head height data above the test section under the stable pressure state according to the pressure change data; S400: opening the flow controller 64, and adjusting the water discharge flow rate to a predetermined value. Set the flow value, and obtain the pressure change data and flow information of the current test section during the water release test; S500: calculate the current groundwater head height above the test section under a specific flow rate based on the pressure change data and the flow change data; S600: obtain the groundwater level drop value per unit time based on the change in groundwater head height data above the test section calculated based on the water pressure data under different flow conditions, and draw a relationship curve between the water release test flow rate and the water level drop; S700: after a period of time after the water release flow rate has stabilized, turn off the flow controller 64 and obtain the water pressure recovery process data.

[0047] Follow the above steps and combine the test components and parts structure to operate. The specific operation method is as follows:

[0048] (1) Determine the test section, place the upper and lower pneumatic plugs 51 at the test section, and seal the test section;

[0049] (2) Variable flow rate water discharge can be achieved by using the flow controller 64 and the instantaneous flow meter 62;

[0050] (3) using the storage pressure sensor 63 to record the instantaneous pressure change of the test section during the water release test;

[0051] (4) using the instantaneous flow meter 62 to record the instantaneous flow change of the test section during the water discharge test;

[0052] (5) The data recorded by the instantaneous flow meter 62 and the storage pressure sensor 63 are processed by the control terminal 7;

[0053] (6) Turn off the flow controller 64 and wait until the water pressure is stable. The stable water pressure is the water pressure of the test section. The water pressure of the test section can be converted into the groundwater head height above the test section.

[0054] (7) Turn on the flow controller 64 to control the water discharge flow. The storage water pressure sensor 63 and the instantaneous flow meter 62 can record the water pressure and flow data of the test section in real time. The recorded water pressure data can be used to calculate the groundwater level of the test section at a specific flow rate.

[0055] (8) Based on the change in groundwater head height above the test section calculated from the water pressure data under different flow conditions, a relationship curve between the discharge test flow rate and the water level drawdown can be obtained;

[0056] (9) After the water discharge flow rate stabilizes for a period of time, the flow controller 64 is turned off, and the storage water pressure sensor 63 obtains the water pressure recovery process data.

[0057] The present invention provides an in-situ testing device and method for the permeability coefficient of a rock mass 1 based on a directional hole 2, which solves the problem that the permeability coefficient of a rock mass 1 along the tunnel is difficult to directly obtain during tunnel (hole) exploration. The water pressure data of the test section recorded by the storage water pressure sensor 63 can be used to obtain the change of the groundwater level above the borehole in real time, reflecting the water level drop caused by water discharge. The flow controller 64 and the instantaneous flow meter 62 can be used to control and record the water discharge flow in real time, which is used to reflect the change of the groundwater level in the test section under different water discharge flow rates.

[0058] The control terminal 7 is used to calculate the water level recovery calculation method of the fixed flow pumping test. The hydraulic conductivity and permeability coefficient of the test section rock mass 1 are calculated according to the flow and water pressure data recorded by the instantaneous flow meter 62 and the storage water pressure sensor 63, avoiding the influence of the unsteady flow on the calculation results during the water discharge process, and improving the calculation efficiency and accuracy. The flow controller 64 is used to control and record the size of the water discharge flow in real time, so that the change of the water pressure of the test section under different water discharge flow conditions can be conveniently tested. A hydraulic conductivity (T) and permeability coefficient (K) can be calculated in the pressure recovery process under each flow, and a large amount of data can be obtained, which is convenient for obtaining the permeability parameters of the test section rock mass 1 more accurately.

[0059] By using a pneumatic embolism to seal the test section, the permeability of the rock mass 1 in the test section can be obtained more accurately. After repeated tests, the differentiated characteristics of the permeability of the rock mass 1 along the borehole can be reflected, so as to evaluate the segmented water inflow of the tunnel (hole). The vertical borehole water release test requires the calculation of the hydrogeological parameters of the aquifer through the water level changes in the water level observation hole, and the obtained hydrogeological parameters can only roughly reflect the permeability of the entire aquifer. In horizontal directional drilling, by isolating the test section, the change of water pressure in the test section can be recorded by the storage water pressure sensor 63, so as to convert the change of the groundwater level. No water level observation hole is required, which greatly reduces the test cost.

[0060] In the present disclosure, the calculation formula for the groundwater level drop value s' per unit time is:

[0061]

[0062] Where, Q-discharge flow, m 3 / d;

[0063] s-water level drawdown, m;

[0064] T-hydraulic conductivity, m 2 / d;

[0065] t-experimental duration, d;

[0066] t'-time for water level to recover, d;

[0067] The permeability coefficient K = T / M, M is the thickness of the aquifer.

[0068] Under a stable flow rate, the water pressure data in the storage water pressure sensor is converted into water head height (H), and the change value of water head height per unit time is calculated as the groundwater level drop per unit time (s'). In order to eliminate the influence of the unsteady flow in the early stage of water release on the experimental calculation results, the s'-l gt / t' straight line is drawn using the water level recovery process of the water release test, and the slope is calculated to obtain the aquifer conductivity (T) and permeability (K).

[0069] example: Figure 2 This is the curve of pressure change with time in the pressure recovery stage during the directional hole water discharge test; before the pressure recovery, the instantaneous flow meter measured a stable flow rate of 1.5L / s. During the whole process, the slope of the fitted s'-l gt / t' line was 0.44. By calculating T = 1.6m 2 / s, and the permeability coefficient K = 7.6 cm / s. In the calculation process, the thickness of the aquifer is replaced by the stable head height during the recovery process.

[0070] It should be noted that when the flow controller is closed (the flow rate is 0), the water pressure of the test section obtained by the storage water pressure sensor is the water pressure caused by the original groundwater level. When the flow controller is turned on (the flow rate is greater than 0), the water pressure of the test section obtained by the storage water pressure sensor is the water pressure caused by the groundwater level in the test section under this flow rate.

[0071] It should be noted that the difference between the water pressure (P0) obtained by the storage water pressure sensor when the flow controller is turned off and the water pressure (P1) obtained by the storage water pressure sensor when the flow controller is turned on can be converted to the drop in groundwater level in the test section (s). In this way, the drop in groundwater level per unit time can be calculated based on the measured parameters.

[0072] In an embodiment provided in the present disclosure, a working tube 3 is inserted into the directional hole 2, and a flower tube 4 with a leakage hole is provided on the working tube 3; both ends of the flower tube 4 are respectively sealedly connected to the directional holes, thereby ensuring the sealing of the test section, which is beneficial to improving the accuracy of the test results; the flow controller 64 is arranged on the working tube 3, so that the tester can directly operate the flow controller 64, thereby completing the adjustment of the flow according to the test stage.

[0073] In one embodiment provided in the present disclosure, pneumatic plugs 51 are respectively provided at both ends of the flower tube 4 to block the directional hole 2; wherein two groups of pneumatic plugs 51 are arranged at intervals and the distance between the two forms the test section. The pneumatic plugs 51 seal the directional hole 2 by inflation, ensuring that the test section will not be disturbed by external air or other factors when performing the permeability test of the rock mass 1, which helps to accurately obtain the permeability parameters of the rock mass 1, thereby improving the reliability and accuracy of the test results.

[0074] Since the pneumatic plug 51 can be inflated and deflated as needed, it has high flexibility during the test process and can adjust the sealing pressure according to different test requirements to adapt to the test of different rock mass 1 characteristics. By controlling the air pressure, the rock mass 1 rupture or other safety problems caused by improper sealing can be avoided. Compared with the one-time sealing method, the pneumatic plug 51 can be reused, which reduces the test cost. The use of chemical sealants is reduced by using the pneumatic plug 51 for sealing, which is more environmentally friendly.

[0075] In the present disclosure, two groups of pneumatic embolic plugs 51 are connected via a high-pressure air pipe 52 , which extends to the outside of the directional hole and is connected to a gas source; an embolic pressure gauge 53 is provided on the high-pressure air pipe 52 .

[0076] The two groups of pneumatic plugs 51 are connected by a high-pressure air pipe 52, so that the two groups of plugs can be uniformly controlled, and inflation or deflation operations can be performed simultaneously. A plug pressure gauge 53 is provided on the high-pressure air pipe 52, so that the operator can monitor the air pressure of the plug in real time, which helps to find potential air pressure problems in time, thereby avoiding safety risks caused by excessive or low pressure and ensuring the accuracy and consistency of the sealing pressure.

[0077] In the present disclosure, the working pipe 3 is provided with an instantaneous flow meter 62, an instantaneous pressure gauge 61 and a pressure sensor 63; the flow controller 64 is set in the area where the working pipe 3 is located outside the directional hole; the instantaneous flow meter 62 is set in the area where the working pipe 3 is located outside the directional hole; the instantaneous pressure gauge 61 is located between the flow controller 64 and the instantaneous flow meter 62; the pressure sensor 63 is located at the front end of the flower pipe 4; wherein the instantaneous flow meter 62, the instantaneous pressure gauge 61 and the pressure sensor 63 are all connected to the control terminal 7 for communication, and the control terminal 7 is used to calculate the water conductivity and permeability of the test section rock mass 1 according to the flow change data and the pressure change data. The pressure sensor 63 and the instantaneous flow meter 62 can record the water pressure and flow data of the test section in real time, and the groundwater level of the test section under a specific flow rate can be converted by the recorded water pressure data. According to the change of the groundwater head height above the test section calculated by the water pressure data under different flow conditions, the relationship curve between the water discharge test flow rate and the water level drop can be obtained.

[0078] 7. The in-situ test method for permeability of rock mass 1 based on directional hole 2 according to claim 6 is characterized in that the calculation formula of hydraulic conductivity and permeability is: K = T / M,

[0079] Where, T-hydraulic conductivity, m 2 / d; M is the thickness of the aquifer.

[0080] According to a second aspect of the present disclosure, an in-situ testing device for permeability of a rock mass 1 based on a directional hole 2 is provided.

[0081] See also Figure 1As shown, the in-situ testing device for the permeability coefficient of the rock mass 1 is used for the in-situ testing method for the permeability coefficient of the rock mass 1 as described in the first aspect, and the in-situ testing device for the permeability coefficient of the rock mass 1 comprises: a working tube 3, a pneumatic plug 51 and a high-pressure air pipe 52; the working tube 3 is provided with a flower tube 4 with a leak hole; both ends of the flower tube 4 are respectively provided with pneumatic plugs 51 for blocking the directional hole 2; the two pneumatic plugs 51 are connected through the high-pressure air pipe 52, and the pneumatic plugs 51 are connected to the gas source through the high-pressure air pipe 52; along the flow direction of the liquid, the working tube 3 is provided with a flow controller 64, an instantaneous pressure gauge 61, an instantaneous flow meter 62 and a pressure sensor 63 in sequence, wherein only the pressure sensor 63 is arranged in the area where the working tube 3 is located in the directional hole; the instantaneous pressure gauge 61, the instantaneous flow meter 62 and the pressure sensor 63 are all communicatively connected to the control terminal 7.

[0082] The instantaneous flow meter 62 and the instantaneous pressure gauge 61 can measure the flow and pressure in the working tube 3 in real time, providing accurate data support. The pressure sensor 63 is located at the front end of the flower tube 4, which can record the water pressure data of the test section in real time, providing a basis for analyzing the hydrogeological characteristics of the rock mass 1. The flow controller 64 is set in a specific area of ​​the working tube 3, which can automatically adjust the flow of the working tube 3 to maintain the stability of the test conditions. The instantaneous flow meter 62, the instantaneous pressure gauge 61 and the pressure sensor 63 are all connected to the control terminal 7 for communication, realizing integrated management and real-time monitoring of data.

[0083] The control terminal 7 can calculate the hydraulic conductivity and permeability of the test section rock mass 1 based on the flow and pressure change data, providing key parameters for hydrogeological analysis. The groundwater level of the test section at a specific flow rate can be converted through the recorded water pressure data, which helps to understand the changes in the groundwater level.

[0084] Based on the water pressure data under different flow conditions, the change in groundwater head height above the test section can be calculated, and then the relationship curve between the discharge test flow and the water level drop can be obtained. Through precise control and measurement, the accuracy of the test is improved, making the obtained hydrogeological parameters more reliable.

[0085] The real-time recording and monitoring function allows the operator to make timely adjustments according to the test situation and optimize the test process. The system can record key data during the test to facilitate subsequent data analysis and research. This configuration allows the test to be carried out under different environmental conditions, improving the adaptability and flexibility of the test.

[0086] By recording the water pressure data of the test section in real time through the pressure sensor 63, the change of the groundwater level above the borehole can be obtained, which helps to reflect the water level drop caused by water release. The use of the flow controller 64 and the instantaneous flow meter 62 allows the size of the water release flow to be controlled and recorded in real time, which is crucial for analyzing the change of the groundwater level under different water release flows.

[0087] The control terminal 7 adopts a constant flow pumping test water level recovery calculation method, which can reduce the impact of unsteady flow on the calculation results and improve the calculation efficiency and accuracy. Under different water discharge flow conditions, the water pressure changes recorded by the flow controller 64 can be used to calculate the hydraulic conductivity (T) and permeability (K), thereby obtaining a large amount of data, which helps to more accurately obtain the permeability parameters of the test section rock mass 1.

[0088] By repeating the test, the differentiation characteristics of the permeability of the rock mass 1 along the borehole can be reflected, which is very useful for evaluating the segmented water inflow of the tunnel (hole). Compared with the traditional vertical borehole water discharge test, the horizontal directional drilling test records the water pressure changes through the test section isolation and storage water pressure sensor 63, avoiding the need for water level observation holes, thereby reducing the test cost. This method can be carried out under different geological and hydrological conditions and has good environmental adaptability. All measuring equipment is connected to the control terminal 7 for communication, realizing integrated data management and real-time monitoring. By accurately controlling the water discharge flow and real-time monitoring of water level changes, the risks that may arise during the test can be better managed. The large amount of accurate data obtained provides a scientific basis for hydrogeological analysis and tunnel (hole) water inflow evaluation, which helps to make more accurate decisions.

[0089] In the present disclosure, the type of pressure sensor 63 is an in-hole storage type pressure sensor 63 .

[0090] In the present disclosure, the controller is configured as a central processing unit (CPU), which is preset with a mathematical model (such as the calculation formula recorded in the text), and the CPU has the ability to process signals.

[0091] Specifically, in the present invention, the controller may also be configured as a PLC logic controller. In other embodiments, the controller may also be configured as a digital signal processor (DSP), an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0092] In the present disclosure, the controller is connected to the instantaneous pressure gauge 61, the instantaneous flow meter 62 and the pressure sensor 63 through cable communication. In other embodiments, the controller can also be connected to the instantaneous pressure gauge 61, the instantaneous flow meter 62 and the pressure sensor 63 through wireless communication modules such as WiFi modules and ZigBee modules. In this regard, those skilled in the art can flexibly configure under the technical concept of the present disclosure.

[0093] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0094] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0095] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. An in-situ test method for rock mass permeability based on directional holes, characterized in that: The following steps are involved: S100: Determine and seal the test section, and wait for the groundwater to overflow the orifice naturally; obtain the pressure change data and flow information of the current test section during the water release test. S200: using a flow controller to change the water discharge flow rate, and obtaining pressure change data and flow information of the current test section during the water discharge test; S300: Turn off the flow controller, obtain the pressure change data of the current test section after the water pressure is stabilized, and calculate the current groundwater head height information above the test section under the stable pressure state according to the pressure change data; S400: Turn on the flow controller, adjust the water discharge flow to a preset flow value, and obtain the pressure change data and flow information of the current test section during the water discharge test; S500: calculating the current groundwater head height above the test section at a specific flow rate based on the pressure change data and the pressure change data; S600: obtaining the groundwater head height information change above the test section calculated based on the water pressure data under different flow conditions, obtaining the groundwater head water level drop value per unit time, and drawing a relationship curve between the water release test flow rate and the water level drop; S700: After the water discharge flow is stable for a period of time, the flow controller is turned off to obtain the water pressure recovery process data.

2. The in-situ testing method for rock mass permeability coefficient based on directional holes according to claim 1 is characterized in that: The calculation formula for the groundwater level drop s' per unit time is: Where, Q-discharge flow, m 3 / d; s-water level drawdown, m; T-hydraulic conductivity, m 2 / d; t-experimental duration, d; t'-time for water level to recover, d; The permeability coefficient K = T / M, M is the thickness of the aquifer.

3. The in-situ testing method of rock mass permeability coefficient based on directional holes according to claim 1 is characterized in that: A test tube is provided in the directional hole, which is connected in sequence to the pneumatic upper plug, the flower tube, the storage water pressure sensor, and the pneumatic lower plug; the test section is between the pneumatic upper and lower plugs, and the flow controller is arranged on the high-pressure water pipe.

4. The in-situ testing method for rock mass permeability coefficient based on directional holes according to claim 3 is characterized in that: The pneumatic upper and lower embolic plugs are connected through a high-pressure air pipe, which extends to the outside of the directional hole and is connected to the air source; an embolic pressure gauge is provided on the high-pressure air pipe.

5. The in-situ testing method of rock mass permeability coefficient based on directional holes according to claim 3 is characterized in that: The high-pressure water pipe is provided with an instantaneous flow meter and an instantaneous pressure gauge.

6. The in-situ testing method for rock mass permeability coefficient based on directional holes according to claim 3, characterized in that: The storage type pressure sensor is located in the test section and is connected to the flower tube. The flow controller is arranged in the area where the high-pressure water pipe is located outside the directional hole; the instantaneous flow meter is arranged in the area where the working pipe is located outside the directional hole; the instantaneous pressure gauge is located between the flow controller and the instantaneous flow meter; Among them, the instantaneous flow meter and the instantaneous pressure gauge are both communicatively connected to the control terminal. The control terminal is used to store the test section pressure according to the flow change data and the pressure change data. The storage pressure sensor stores the test section pressure. After the test is completed, the test section pressure change data is exported through the control terminal to further calculate the water conductivity and permeability coefficient of the rock mass in the test section.

7. The in-situ testing method for rock mass permeability based on directional holes according to claim 6 is characterized in that: The calculation formula of hydraulic conductivity and permeability coefficient is: K = T / M, Where, T-hydraulic conductivity, m 2 / d; M is the thickness of the aquifer.

8. An in-situ testing device for rock mass permeability based on directional holes, characterized in that: The rock mass permeability coefficient in-situ testing device is used for the rock mass permeability coefficient in-situ testing method according to any one of claims 1 to 7, and the rock mass permeability coefficient in-situ testing device comprises: a high-pressure water pipe, a flow controller, an instantaneous pressure gauge, an instantaneous flow meter, a test pipe, a pneumatic upper plug, a flower pipe, a storage pressure sensor, a lower plug and a high-pressure air pipe; The instantaneous pressure meter and the instantaneous flow meter are both communicatively connected to the control terminal. The storage pressure sensor stores the test section pressure. After the test is completed, the test section pressure change data is exported through the control terminal.

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