Deep stratum three-dimensional in-situ stress continuous measuring device and method

Abstract

The application discloses a kind of deep stratum three-dimensional in-situ ground stress continuous measuring device and method, belong to ground stress measurement technical field.The application includes shell, is connected with a plurality of camera in shell, a plurality of water cutter head, image acquisition module, water cutter supply module and data transmission module;A plurality of camera circumferential setting is used to shoot outer circumferential image, a plurality of water cutter head is set on shell corresponding camera, a plurality of camera and image acquisition module are electrically connected, image acquisition module and data transmission module are electrically connected, a plurality of water cutter head and water cutter supply module are communicated.The application can continuously monitor ground stress, can be used under complex geological conditions, and it is easy to operate, high efficiency, greatly reduces test cost and time input.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of in-situ stress measurement, and particularly relates to a device and method for continuous measurement of in-situ stress in deep strata. BACKGROUND

[0002] With the gradual advancement of deep mines, underground storage facilities and geothermal energy utilization into the deep crust, it is essential to master the in-situ stress state of rock mass to ensure the safety and stability of engineering. The stress distribution of rock mass directly affects the stability judgment in engineering design and construction, as well as the deformation and damage prediction of surrounding rock under external disturbance. Traditional in-situ stress measurement methods, such as stress relief method and hydraulic fracturing method, can only measure discrete points and cannot provide continuous spatial distribution information of rock mass stress. For example, the commonly used hollow inclusion stress relief method is to drill a hole around the chamber and install a hollow cylinder, then gradually relieve the stress on it, and then calculate the original rock stress. Although this method is mature and widely used, the construction process is relatively complex, and each measurement from drilling to stress relief to data collection takes a long time. Especially when operating in deep holes, the pasting of the inclusion, stress relief and data collection must be completed in a narrow space, which requires high precision for operation. The test process is also easily disturbed by the external environment, affecting the accuracy of the measurement results. In addition, the stress of rock mass changes dynamically with geological movement and engineering construction, and this method can only obtain discrete stress data during the relief process, and cannot monitor in real time.

[0003] If the existing method needs to obtain stress data at different stages, it must repeat the process of drilling and installing the inclusion multiple times, which greatly increases the time cost and economic investment of construction. In deep strata, due to complex geological conditions, high temperature and pressure, rock mass has obvious anisotropy and nonlinearity, making the limitations of single-point measurement more prominent. This makes researchers and engineers urgently need a continuous stress measurement technology in three-dimensional space and time to improve the accuracy and coverage of the stress field.

[0004] Therefore, a device and method for continuous measurement of in-situ stress in deep strata are proposed. SUMMARY

[0005] To solve the above technical problems, the present application provides a device and method for continuous measurement of in-situ stress in deep strata.

[0006] In order to achieve the above object, the application provides a deep stratum three-dimensional in-situ ground stress continuous measurement device, comprising: a shell, a plurality of cameras, a plurality of water cutter heads, an image acquisition module, a water cutter supply module and a data transmission module are connected in the shell; a plurality of cameras are arranged circumferentially to shoot the image of the shell periphery, a plurality of water cutter heads are arranged on the shell corresponding to the cameras, a plurality of cameras are electrically connected with the image acquisition module, the image acquisition module is electrically connected with the data transmission module, and a plurality of water cutter heads are communicated with the water cutter supply module.

[0007] According to the deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the application, the two ends of the shell are fixedly connected with limiting supports, a plurality of supporting legs are circumferentially arranged on the limiting supports, the supporting legs are arc-shaped, and the supporting legs are telescopically connected with the main bodies of the limiting supports.

[0008] According to the deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the application, the water cutter head is a ring-shaped cutter head, the inner diameter of the water cutter head is greater than the outer diameter of the camera, and the camera is arranged in the inner ring of the water cutter head.

[0009] According to the deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the application, the camera is a high-definition camera, and the lens of the camera is telescopic.

[0010] On the other hand, the application also provides a deep stratum three-dimensional in-situ ground stress continuous measurement method, which can be mutually referred to with the above deep stratum three-dimensional in-situ ground stress continuous measurement device:

[0011] Step one: drilling is carried out at a deep ground stress monitoring point, and the drilling coordinate system is measured;

[0012] Step two: the deep stratum three-dimensional in-situ ground stress continuous measurement device is installed at the monitoring point, and the section where the monitoring point is located at this time is regarded as a first monitoring section;

[0013] Step three: the camera acquires the initial image of the first monitoring section and transmits it to the image acquisition module, the image acquisition module pre-processes the data of the initial image and transmits it to the data transmission module, and the data transmission module transmits the acquired initial image data; subsequently, the water cutter supply module provides water flow and pressure to the water cutter head, the high-pressure water flow shot by the water cutter head cuts the rock mass around the measuring point to form a cutting line, and the stress is released, at the same time, the camera, the image acquisition module and the data transmission module acquire the change data of the measuring point characteristics before and after the stress is released, and the first measurement is completed;

[0014] Step four: lifting the deep stratum three-dimensional in-situ ground stress continuous measurement device and fixing it to the hole wall again, and the cross section of the monitoring point is the second monitoring section;

[0015] Step five: opening the camera, the image acquisition module and the data transmission module to start long-term measurement of the section data, continuously collecting the hole wall images and obtaining long-term change data of the continuous monitoring point features;

[0016] Step six: based on the initial data of the first measurement and the real-time data of the continuous measurement, the stress state of the monitoring point is calculated by using the elastic theory and the least square method.

[0017] According to the deep stratum three-dimensional in-situ ground stress continuous measurement method provided by the application, in step six, the initial strain of the deep hole monitoring point is calculated by using the data of the first monitoring section and the characteristic line segment basic parameters in the second monitoring section; the initial strain data of the second monitoring section are superimposed with the continuous strain increment to obtain the strain full amount of the second monitoring section, and the strain full amount of the second monitoring section is obtained again by using the elastic theory and the least square method, that is, the stress full amount of the deep hole.

[0018] According to the deep stratum three-dimensional in-situ ground stress continuous measurement method provided by the application, in step six, the lifting height of the deep stratum three-dimensional in-situ ground stress continuous measurement device is 5-10 times the height of the cutting range.

[0019] Compared with the prior art, the application has the following advantages and technical effects:

[0020] The measurement device is placed in the drilling hole to be measured, the camera and the image acquisition module are used to collect the image data of the monitoring point in the drilling hole, and the image data is transmitted to the data transmission module, and the data transmission module is used to transmit the collected image data outward; the water jet supply module provides high-pressure water flow for the water jet head, the water jet head can cut the rock mass around the monitoring point to release the stress, and then the camera and the image acquisition module collect the image data of the monitoring point in the drilling hole again to further obtain the change data of the monitoring point features before and after the stress release. The deep stratum three-dimensional in-situ ground stress continuous measurement device of the application releases the stress by cutting with the water jet head instead of the traditional drilling hole release method, solves the problem of deep hole stress release, and can realize real-time data collection and transmission through the camera, the image acquisition module and the data transmission module, realizes the long-time continuous measurement of the deep surrounding rock stress, monitors the change rule of the deep original rock stress under the influence of geological movement and engineering, and has the advantages of simple operation and high efficiency, significantly reduces the test cost and time investment. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this application. The embodiments of the application illustrated in the drawings are intended to explain the aspects of the present application and are not limiting of the present application. In the drawings:

[0022] Figure 1 Schematic diagram for the first monitoring section and the second monitoring section in the application;

[0023] Figure 2 Schematic diagram for the structure of the deep stratum three-dimensional in-situ stress continuous measurement device in the application;

[0024] Figure 3 Sectional view of the deep stratum three-dimensional in-situ stress continuous measurement device in the application;

[0025] Figure 4 Schematic diagram for the identification point and the characteristic line segment in the application.

[0026] In the figure: 1, the first monitoring section; 2, the second monitoring section; 3, the cutting line; 4, the image acquisition module; 5, the camera; 6, the water cutter head; 7, the water cutter supply module; 8, the limiting support; 9, the data transmission module. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0028] In order to make the above objectives, characteristics and advantages of the application more apparent, the application will be described in further detail below with reference to the drawings and specific embodiments.

[0029] Reference Figures 1 to 4 As shown in the figure, the embodiment provides a deep stratum three-dimensional in-situ stress continuous measurement device, which comprises: an outer shell, a plurality of cameras 5, a plurality of water cutter heads 6, an image acquisition module 4, a water cutter supply module 7 and a data transmission module 9 are connected in the outer shell; the plurality of cameras 5 are circumferentially arranged and used for shooting the outer peripheral image of the outer shell, the plurality of water cutter heads 6 are arranged on the outer shell corresponding to the cameras 5, the plurality of cameras 5 are electrically connected with the image acquisition module 4, the image acquisition module 4 is electrically connected with the data transmission module 9, and the plurality of water cutter heads 6 are communicated with the water cutter supply module 7.

[0030] The measuring device is placed in a drill hole to be measured, and the camera 5 and the image acquisition module 4 are used to acquire image data of a measuring point in the drill hole, and the image data is transmitted to the data transmission module 9, and the data transmission module 9 is used to transmit the collected image data outward; the water jet supply module 7 supplies water flow and pressure for the water jet head 6, and the water jet head 6 can cut the rock mass around the monitoring point to release stress, and then the camera 5 and the image acquisition module 4 acquire image data of the measuring point in the drill hole again, so that the change data of the characteristics of the measuring point before and after stress release can be obtained.

[0031] Referring to Figure 4 , ~ The original feature identification point is shown in the figure. ~ The feature identification point after deformation is shown in the figure. , , , The connecting line between the original feature identification points is a feature line segment. , , , The feature line segment after deformation is shown in the figure.

[0032] The deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the application solves the problem of stress release in a deep hole by replacing the traditional drill hole release method, and can realize real-time data acquisition and transmission through the camera 5, the image acquisition module 4 and the data transmission module 9, so as to realize the long-time continuous measurement of the stress of deep surrounding rock and monitor the change rule of the stress of deep original rock under the influence of geological movement and engineering.

[0033] According to the deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the embodiment, the two ends of the shell are fixedly connected with limiting supports 8, the limiting supports 8 are circumferentially provided with a plurality of supporting legs, the supporting legs are arc-shaped, and the supporting legs are telescopically connected to the main body of the limiting supports 8.

[0034] The limiting supports 8 limit the position of the device in the deep hole, prevent disturbance from affecting image acquisition and the cutting process of the water jet head 6, and the curvature of the supporting legs of the limiting supports 8 is the same as the curvature of the hole wall, which is conducive to stable support.

[0035] According to the deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the embodiment, the water jet head 6 is a ring-shaped cutter head, the inner diameter of the water jet head 6 is greater than the outer diameter of the camera 5, and the camera 5 is arranged in the inner ring of the water jet head 6.

[0036] The ring-shaped water jet head 6 surrounds the camera 5, so that stress release of the corresponding monitoring point of the camera 5 can be realized.

[0037] According to the deep stratum three-dimensional in-situ ground stress continuous measurement device provided by the embodiment, the camera 5 is a high-definition camera, and the lens of the camera 5 is telescopic.

[0038] The lens of the camera 5 is telescopic, the length of the lens can be adjusted according to the inner diameter of the deep hole, and after the adjustment, wall-adhesion measurement is realized, so as to solve the problem of the influence of groundwater in the deep hole on the image definition.

[0039] In another aspect, the embodiment also provides a deep stratum three-dimensional in-situ ground stress continuous measurement method, which can be mutually referred to with the above deep stratum three-dimensional in-situ ground stress continuous measurement device.

[0040] Step one: drilling at a deep ground stress monitoring point and measuring the drilling coordinate system;

[0041] Step two: installing the deep stratum three-dimensional in-situ ground stress continuous measurement device at the monitoring point, and assuming that the section where the monitoring point is located is a first monitoring section 1;

[0042] The deep stratum three-dimensional in-situ ground stress continuous measurement device is installed through the limiting support 8.

[0043] Step three: the camera 5 collects the initial image of the first monitoring section 1 and transmits it to the image acquisition module 4, the image acquisition module 4 pre-processes the data of the initial image and transmits it to the data transmission module 9, and the data transmission module 9 transmits the collected initial image data; then the water jet supply module 7 provides water flow and pressure to the water jet head 6, the high-pressure water flow emitted by the water jet head 6 cuts the rock mass around the measuring point to form a cutting line 3, and the stress is released, at the same time, the camera 5, the image acquisition module 4 and the data transmission module 9 acquire the change data of the measuring point characteristics before and after the stress is released, and the first measurement is completed;

[0044] Before collecting the image, the length of the lens can be adjusted according to the inner diameter of the deep hole, so as to obtain a clearer image.

[0045] Step four: lifting the deep stratum three-dimensional in-situ ground stress continuous measurement device and fixing the deep stratum three-dimensional in-situ ground stress continuous measurement device on the hole wall again, assuming that the section where the monitoring point is located is a second monitoring section 2;

[0046] Step five: turning on the camera 5, the image acquisition module 4 and the data transmission module 9 to start long-term measurement of the section data, continuously collecting the hole wall image, and acquiring the long-term change data of the measuring point characteristics;

[0047] Step six: based on the initial data of the first measurement and the real-time data of the continuous measurement, the stress state of the monitoring point is calculated by using the elastic theory and the least square method.

[0048] According to the deep stratum three-dimensional in-situ stress continuous measurement method provided by the embodiment, in step six, the initial strain of the deep hole measuring point is calculated by using the data of the first monitoring section 1 and the basic parameters of the characteristic line segment in the second monitoring section 2; the initial strain data of the second monitoring section 2 is superimposed with the continuous strain increment to obtain the strain full value of the second monitoring section 2, and the strain full value of the second monitoring section 2 is obtained again by using the elastic theory and the least square method, that is, the stress full value of the deep hole.

[0049] The specific calculation process is as follows:

[0050] S1: stress component of the first monitoring section 1 、 、 、 、 、 Calculation. Based on the data obtained from the first monitoring section 1, the stress component of the first monitoring section 1 is calculated, and an equation is established based on the elastic theory:

[0051] In the formula, L1 is the initial length of the characteristic line segment in the first monitoring section 1, L1i is the length of the characteristic line segment in the first monitoring section 1 after being released, ε1 is the strain value of the characteristic line segment in the first monitoring section 1, θ1 is the polar angle of the characteristic line segment cluster in the first monitoring section 1, φ1 is the angle of the characteristic line segment in the first monitoring section 1, E is the elastic modulus of the rock, and μ is the Poisson's ratio of the rock. .

[0052] Let: , then:

[0053]

[0054] In the formula, the subscript 1 represents the related parameters of the characteristic line segment in the first monitoring section 1, i=1~3 is the cluster number of each characteristic line segment in the first group of measuring points, j=1~4 is the number of each characteristic line segment in each characteristic line segment cluster; L1 is the initial length of the characteristic line segment in the first monitoring section 1, L1i is the length of the characteristic line segment in the first monitoring section 1 after being released, ε1 is the strain value of the characteristic line segment in the first monitoring section 1; θ1 is the polar angle of the characteristic line segment cluster in the first monitoring section 1; φ1 is the angle of the characteristic line segment in the first monitoring section 1; E is the elastic modulus of the rock; μ is the Poisson's ratio of the rock; 、 、 、 、 、 S1 is the six stress components of the first monitoring section 1; 、 ... is the equation coefficient.

[0055] The normal equation of the strain value equation of the characteristic line segment is constructed based on the least square principle, and the stress component S1 of the first monitoring section 1 is obtained after arrangement. , 、 、 、 、 is:

[0056]

[0057] where s is the number of observation equations, i.e. the number of characteristic line segments, and i is the number of characteristic line segment clusters of a single monitoring section, and j is the number of characteristic line segments of different directions included in each characteristic line segment cluster; is the strain difference between the front and rear characteristic line segments.

[0058] S2: initial strain of the second monitoring section 2 Calculation. Based on the stress components obtained from the first monitoring section 1 and the polar angle and the angle of the characteristic line segment of the characteristic line segment cluster of the second monitoring section 2, the initial strain of the second monitoring section 2 is calculated, and an equation is established based on the elastic theory:

[0059]

[0060] where:

[0061]

[0062] where the subscript 1 represents the relevant parameters of the characteristic line segment in the first monitoring section 1, and the subscript 2 represents the relevant parameters of the characteristic line segment in the second monitoring section 2; i = 1 ~ 3 is the number of each characteristic line segment cluster in the second group of measuring points; j = 1 ~ 4 is the number of each characteristic line segment in each characteristic line segment cluster; is the initial strain of the characteristic line segment of the second monitoring section 2; is the polar angle of the characteristic line segment cluster of the second monitoring section 2; is the angle of the characteristic line segment of the second monitoring section 2; E is the elastic modulus of the rock; is the Poisson's ratio of the rock; 、 、 、 、 、 are the six in-situ stress components of the second monitoring section 2; 、 ... are the equation coefficients.

[0063] S3: initial strain of the second monitoring section 2 Calculation. The following equation is established:

[0064]

[0065]

[0066] wherein, is the strain total of the characteristic line segment of the second monitoring section 2 in the continuous monitoring process; is the strain increment of the characteristic line segment of the second monitoring section 2 in the continuous monitoring process; is the initial length of the characteristic line segment of the second monitoring section 2, is the length of the characteristic line segment of the second monitoring section 2 at any moment in the continuous measurement process.

[0067] S4: stress total of the second monitoring section 2 、 、 、 、 、 Calculation. Based on the elastic theory, the following equation is established:

[0068]

[0069] Let: then:

[0070]

[0071] wherein, the subscript 2 represents the relevant parameters of the characteristic line segment in the second monitoring section 2; i=1~3 is the cluster number of each characteristic line segment in the second group of measuring points; j=1~4 is the number of each characteristic line segment in each cluster of characteristic line segments in each group; is the polar angle of the cluster of characteristic line segments; is the angle of the characteristic line segment; E is the elastic modulus of the rock; is the Poisson's ratio of the rock; 、 、 、 、 、 are six ground stress components; 、 ... are equation coefficients.

[0072] Based on the least square principle, the normal equation of the strain equation of the characteristic line segment is constructed, and the stress total of the deep hole measuring point 、 、 、 、 、 is:

[0073]

[0074] the stress total of the second monitoring section 2 obtained , 、 、 、 、 That is the stress full amount of deep hole.

[0075] According to the deep stratum three-dimensional in-situ ground stress continuous measurement method provided by the embodiment, in step six, the deep stratum three-dimensional in-situ ground stress continuous measurement device is lifted to a height of 5-10 times the cutting range.

[0076] When the lifting height is 5-10 times the cutting range, the influence of the first stress release can be eliminated.

[0077] The details of the present application are well known to those skilled in the art.

[0078] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0079] The above-described embodiments are only preferred modes of the present application and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A device for continuous measurement of three-dimensional in-situ ground stress in deep strata, characterized in that, The utility model relates to a kind of deep stratum three-dimensional in-situ ground stress continuous measurement device, including: Shell, several cameras (5), several water cutter heads (6), image acquisition module (4), water cutter supply module (7) and data transmission module (9) are connected in the shell;Several The camera (5) is circumferentially arranged, and the image of the shell periphery is shot, and several water cutter heads (6) are arranged on the shell corresponding to the camera (5), and several The camera (5) is electrically connected with the image acquisition module (4), and the image acquisition module (4) and the data transmission module (9) are electrically connected, and several The water cutter head (6) is communicated with the water cutter supply module (7); The both ends of the shell are fixedly connected with limiting supports (8), the supporting leg of the limiting support (8) is arc-shaped, can be well fitted with the hole wall, the supporting leg is circumferentially provided with a plurality of, and can be telescopically connected on the main body of the limiting support (8); The water cutter head (6) is annular cutter head, the inner diameter of the water cutter head (6) is greater than the outer diameter of the camera (5), and the camera (5) is arranged in the inner ring of the water cutter head (6); The camera (5) is high-definition camera, and the lens of the camera (5) can be telescopic.

2. A deep stratum three-dimensional in-situ ground stress continuous measurement method, the deep stratum three-dimensional in-situ ground stress continuous measurement device of claim 1 is characterized in that: Step one: at the monitoring point of deep ground stress, drill to the predetermined depth by selecting the appropriate drilling position, and determine the drilling column coordinate system by measurement; Step two: install the deep stratum three-dimensional in-situ ground stress continuous measurement device at the monitoring point, and set the section where the monitoring point is located as the first monitoring section (1); Step three: the initial image of the first monitoring section (1) is collected by the camera (5) and transmitted to the image acquisition module (4), the image acquisition module (4) pre-processes the data of the initial image and transmits it to the data transmission module (9), and the data transmission module (9) transmits the collected initial image data; Then the water cutter supply module (7) provides high-pressure water flow to the water cutter head (6), the high-pressure water flow emitted by the water cutter head (6) cuts the rock mass around the measuring point to form a cutting line (3), to relieve stress, while the camera (5), image acquisition module (4) and data transmission module (9) obtain the change data of the measuring point features before and after stress relief, and complete the first measurement; Step four: the deep stratum three-dimensional in-situ ground stress continuous measurement device is lifted to a certain height, and the deep stratum three-dimensional in-situ ground stress continuous measurement device is fixed to the hole wall again, and the section where the monitoring point is located is set as the second monitoring section (2); Step five: turn on the camera (5), the image acquisition module (4) and the data transmission module (9) to start long-term measurement of section data, continuously collect hole wall images, and obtain long-term change data of continuous measuring point features; Step six: based on the initial data of the first measurement and the real-time data of continuous measurement, the stress state of the monitoring point is calculated by using the elastic theory and the least square method.

3. The method of claim 2, wherein: In step six, the initial strain of the deep hole monitoring point is calculated by using the data of the first monitoring section (1) and the basic parameters of the characteristic line segment in the second monitoring section (2); the initial strain data of the second monitoring section (2) are superimposed with the continuous strain increment to obtain the total strain of the second monitoring section (2); and the total strain of the second monitoring section (2) obtained by using the elasticity theory and the least square method is the total stress of the deep hole monitoring point.

4. The method of claim 2, wherein: In step six, the deep formation three-dimensional in-situ stress continuous measurement device is lifted to a height of 5-10 times the height of the cutting range.

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