Automatic deep hole displacement observation device and method based on stress-strain measurement

Abstract

The invention relates to the technical field of deep hole displacement observation, and discloses an automatic deep hole displacement observation device and method based on stress strain measurement, and the device comprises an observation pipe which is vertically buried in a drill hole; the plurality of strain gauges are arranged on the outer wall of the observation pipe and are used for acquiring axial strain and circumferential strain data in different depths and directions in real time; the data acquisition module is provided with a wireless transmission module and is connected with the strain gauges through the wireless transmission module; a displacement integral algorithm and a finite element model are built in the data processing unit, and the data processing unit is used for calculating the sliding mass displacement and a three-dimensional deformation field; and the monitoring terminal receives and displays the displacement result and the early warning information. According to the invention, the position and deformation of the sliding surface are judged by observing the stress change condition of the pipe wall, and the sliding direction and deformation condition of the landslide are judged. That is to say, stress-strain changes of the pipe wall are observed by monitoring the deep hole, and the sliding direction and deformation condition of the landslide are indirectly obtained by inverting the deformation amount and direction of the slip mass.

Description

Technical Field

[0001] The present invention relates to the technical field of deep hole displacement observation, and in particular to an automatic deep hole displacement observation device and method based on stress-strain measurement. Background Art

[0002] At present, deep hole displacement is measured by "the inclinometer pulley sliding up and down along the cross-symmetrically distributed guide grooves in the inclinometer tube, so that the sensor guide wheel is stuck in the guide groove on the inner wall of the inclinometer tube, and the data measured by the sensor is displayed on the reading instrument by the wire. It is mainly through the pendulum that the inclination angle between the sensor and the plumb line is measured under the action of gravity, and then the horizontal displacement of each point in the vertical position is calculated", and then the sliding surface position and the displacement deformation of the sliding body are judged based on this.

[0003] However, this method has certain limitations: It is susceptible to external interferences such as construction vibration and temperature changes, and can only obtain displacement in a single direction, making it difficult to fully reflect the three-dimensional deformation characteristics of the sliding body. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the present invention proposes an automatic observation device and method for deep hole displacement based on stress and strain measurement to solve the above technical problems.

[0005] In a first aspect, a deep hole displacement automatic observation device based on stress and strain measurement is provided, comprising: Observation tube, buried vertically in the borehole; A plurality of strain gauges are provided on the outer wall of the observation tube for real-time collection of axial strain and hoop strain data at different depths and directions; a data acquisition module, configured with a wireless transmission module and connected to the strain gauge via the wireless transmission module; Data processing unit, with built-in displacement integration algorithm and finite element model, used to calculate the displacement of the sliding body and the three-dimensional deformation field; The monitoring terminal receives and displays displacement results and warning information.

[0006] Furthermore, the plurality of strain gauges are axially spaced apart along the outer wall of the observation tube and symmetrically distributed along the circumferential direction.

[0007] Furthermore, it also includes: The temperature sensor and the osmometer are both fixed on the outer wall of the observation tube and are used to synchronously collect deep hole environmental temperature and seepage pressure data.

[0008] Furthermore, the data processing unit is equipped with a dynamic compensation module to correct the hoop strain data based on the thermometer seepage pressure data.

[0009] Furthermore, the wireless transmission module is a 4G / 5G communication module for remote real-time data transmission.

[0010] In a second aspect, a method for automatically observing deep hole displacement based on stress and strain measurement is provided, wherein the method comprises: An observation tube is installed in the deep hole, and a plurality of strain gauges are arranged axially at intervals along the outer wall of the observation tube; Real-time collection of axial strain and hoop strain data; Based on the axial strain and hoop strain data, combined with the elastic modulus and Poisson's ratio of the observed pipe material, the pipe wall stress distribution at the corresponding depth is calculated; The deformation and sliding direction of the sliding body are inverted by the stress-strain relationship, and the displacement depth curve is generated by combining the displacement integration algorithm to determine the sliding surface position and three-dimensional deformation field.

[0011] Furthermore, it also includes: Synchronously collect temperature data and seepage pressure data of deep hole environment; Establishing a finite element model based on the temperature data, seepage pressure data, and strain data; Based on the finite element model, the hoop strain data is temperature compensated and the seepage pressure is corrected to output the sliding body displacement result.

[0012] Furthermore, it also includes: The collected strain data is subjected to noise filtering and zero point calibration.

[0013] Furthermore, the sliding surface position is determined by strain mutation points in different directions at the same depth, and the sliding direction is determined by the difference in strain direction.

[0014] Furthermore, the displacement integration algorithm includes: in, For the Depth of sensors is the distance between adjacent sensors; K is the number of sensors; For the The depth of the sensor.

[0015] The invention adopting the above technical solution has the following advantages: 1. The present invention determines the position and deformation of the sliding surface, as well as the direction and deformation of the landslide, by observing changes in pipe wall stress. Specifically, by monitoring changes in pipe wall stress and strain through deep holes, the sliding direction and deformation are indirectly determined by inverting the deformation and direction of the sliding body.

[0016] 2. The present invention arranges stress strain gauges at different depths and directions in the observation pipe, collects strain data of the pipe wall in real time, calculates the deformation, sliding surface position and sliding direction in combination with the mechanical model, and indirectly obtains the sliding direction and deformation of the landslide by inverting the deformation and direction of the sliding body. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0018] Figure 1 This is a system schematic diagram of a deep hole displacement automatic observation device based on stress and strain measurement according to the present invention; Figure 2 This is a flow chart of displacement calculation in an automated deep hole displacement observation method based on stress-strain measurement according to the present invention; Figure 3 This is a compensation correction flow chart for a deep hole displacement automatic observation method based on stress and strain measurement according to the present invention; Figure 4 This is a plan view of the arrangement of strain gauges in an automated deep hole displacement observation device based on stress and strain measurement according to the present invention; Figure 5 This is an automated monitoring distribution diagram in an automated observation device for deep hole displacement based on stress and strain measurement according to the present invention; Figure 6 This is a cross-sectional view of an automated monitoring system in an automated deep hole displacement observation device based on stress and strain measurement according to the present invention.

[0019] Reference numerals: Observation tube 1, strain gauge 2. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0021] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0022] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0023] like Figures 1 to 6 As shown, the present invention is an automatic observation device for deep hole displacement based on stress and strain measurement, comprising: Observation tube 1, vertically buried in the borehole; Multiple strain gauges 2 are provided on the outer wall of the observation tube 1 for real-time collection of axial strain and hoop strain data at different depths and directions; The data acquisition module is equipped with a wireless transmission module and is connected to the strain gauge 2 via the wireless transmission module; Data processing unit, with built-in displacement integration algorithm and finite element model, used to calculate the displacement of the sliding body and the three-dimensional deformation field; The monitoring terminal receives and displays displacement results and warning information.

[0024] Specifically, the deep-hole displacement automatic observation method based on stress-strain methods uses stress changes in the wall of the observation tube 1 to determine the location and deformation of the sliding surface, as well as the direction and deformation of the landslide. In other words, by monitoring the stress and strain changes in the wall of the deep-hole observation tube 1 and inverting the deformation and direction of the sliding body, the landslide direction and deformation are indirectly determined.

[0025] The basic working principle is to arrange stress and strain gauges 2 at different depths and directions in the observation pipe 1, collect the strain data of the pipe wall in real time, and calculate the deformation, sliding surface position and sliding direction in combination with the mechanical model. The sliding direction and deformation of the landslide are indirectly obtained by inverting the deformation and direction of the sliding body.

[0026] In this embodiment, a plurality of strain gauges 2 are axially spaced apart along the outer wall of the observation tube 1 and symmetrically distributed along the circumferential direction.

[0027] In this embodiment, it also includes: The temperature sensor and the osmometer are both fixed to the outer wall of the observation tube 1 and are used to synchronously collect the deep hole ambient temperature and seepage pressure data.

[0028] In this embodiment, the data processing unit is equipped with a dynamic compensation module to correct the hoop strain data based on the thermometer seepage pressure data.

[0029] In this embodiment, the wireless transmission module is a 4G / 5G communication module for remote real-time data transmission.

[0030] In this embodiment, it also includes: a cloud platform.

[0031] Specifically, drilling and observation tube preparation: Drill holes to stable strata at predicted slip surface locations; An observation tube 1 is embedded in the borehole and is made of high-strength material (such as PVC or steel pipe).

[0032] Installation and fixing: Pre-embed strain gauges 2 in the outer wall of the observation tube 1 in a preset direction and position (8 sets of strain gauges 2 are evenly arranged in a 45° circumferential direction); simultaneously install a temperature sensor and a piezometer; Place the observation tube 1 vertically into the drill hole, ensuring that the direction of the strain gauge 2 is consistent with the preset orientation, and the temperature sensor and piezometer are consistent with the above requirements.

[0033] Quick-setting cement mortar or cement slurry is poured into the gap between the borehole and the pipe wall, and the observation pipe 1 is filled with gel material to form a pipe-soil integrated structure after initial solidification.

[0034] Equipment connection and calibration: Connect the strain gauge 2, temperature sensor, and piezometer to the data acquisition module, and configure a wireless transmission module (such as a 4G / 5G module).

[0035] After the filling material has initially solidified, the system is reset to zero to eliminate the installation stress response.

[0036] Automated monitoring: Lead out signal transmission line or wireless transmission module; collect strain data in real time / periodic time and transmit it to the cloud platform via wireless.

[0037] The data analysis software automatically calculates the deformation amount and direction at each depth point, synchronously collects temperature and seepage pressure data, and then establishes a finite element model that includes the temperature field, seepage field, and stress-strain field. Finally, the data processing unit dynamically calculates the temperature and seepage pressure compensation values, and corrects the displacement results in real time. The displacement-depth curve and three-dimensional deformation field are output after eliminating environmental interference.

[0038] In other embodiments, a method for automatically observing deep hole displacement based on stress and strain measurement is provided. An automatic observation device for observing deep hole displacement based on stress and strain measurement according to any of the above items is provided, comprising: An observation tube 1 is installed in the deep hole, and a plurality of strain gauges 2 are arranged axially and spaced apart along the outer wall of the observation tube 1; Real-time collection of axial strain and hoop strain data; Based on the axial strain and hoop strain data, combined with the elastic modulus and Poisson's ratio of the observation pipe 1 material, the pipe wall stress distribution at the corresponding depth is calculated; The deformation and sliding direction of the sliding body are inverted by the stress-strain relationship, and the displacement depth curve is generated by combining the displacement integration algorithm to determine the sliding surface position and three-dimensional deformation field.

[0039] In this embodiment, it also includes: Synchronously collect temperature data and seepage pressure data of deep hole environment; Establish a finite element model based on temperature data, seepage pressure data and strain data; Based on the finite element model, the hoop strain data is temperature compensated and the seepage pressure is corrected to output the sliding body displacement results.

[0040] In this embodiment, it also includes: The collected strain data is subjected to noise filtering and zero point calibration.

[0041] In this embodiment, the position of the sliding surface is determined by the strain mutation points in different directions at the same depth, and the sliding direction is determined by the difference in strain direction.

[0042] Specifically, the strain gauges 2 are arranged as follows: multiple groups of strain gauges 2, temperature sensors, and piezometers are symmetrically arranged along the circumferential direction at a certain interval (e.g., 0.5-1.0 m) on the outer wall of the observation tube 1 (they can be arranged in a circular manner along the borehole wall, such as 0°, 45°, 90°, 135°, 180°, 225°, 270°, etc. The specific arrangement method is reasonably determined according to the monitoring accuracy requirements). Data acquisition: The circumferential strain of the pipe wall under the action of the sliding body is measured by strain gauge 2. Combined with the elastic modulus of the pipe, the stress and deformation of the pipe wall are calculated.

[0043] Output: Temperature and seepage pressure data are collected synchronously, and then a finite element model including temperature field, seepage field and stress-strain field is established; finally, the temperature and seepage pressure compensation values are dynamically calculated in the data processing unit, and the displacement results are corrected in real time; the displacement-depth curve is output after eliminating environmental interference.

[0044] Slip surface determination: The strain mutation point in different directions at the same depth is the slip surface location; the difference in strain direction can reflect the sliding direction (for example, if the compressive strain on one side increases, the tensile strain on the opposite side increases).

[0045] In this embodiment, the displacement integration algorithm includes: in, For the The depth of each sensor; is the distance between adjacent sensors; K is the number of sensors; For the The depth of the sensor.

[0046] Specifically, the displacement calculation formula is derived: Basic assumptions The rock and soil or structural materials around the deep hole are linear elastic and isotropic media.

[0047] The displacement field is distributed continuously and adjustable along the axial (longitudinal) and radial directions of the deep hole.

[0048] The axial strain is measured by multiple sets of strain gauges 2 (such as fiber Bragg gratings, resistance strain gauges) arranged on the hole wall. ) and hoop strain ( ).

[0049] The influence of temperature and seepage pressure data on stress and strain is considered simultaneously, and after eliminating environmental interference, a more realistic displacement-depth curve is output.

[0050] Relationship between three-dimensional displacement field and strain Based on the small deformation theory of elasticity, the relationship between the displacement components (u, v, w) and the strain tensor is: Where V is Poisson's ratio; is the axial strain; is the hoop strain; w is the axis displacement; u, are radial and circumferential displacements; r, , Z are cylindrical coordinate parameters (r is the hole radius, Z is the depth).

[0051] Simplified displacement calculation model For the deep hole axial displacement (the main monitoring target), the circumferential displacement (v ≈ 0) and radial displacement (u w), combined with the boundary conditions, we can get: in, is the axial displacement at depth z; For depth The axial strain at ; C is the integral constant (determined by the displacement of the fixed end of the orifice being zero, C=0). The following is a detailed step-by-step description of the finite element model construction and the calculation of temperature and seepage pressure compensation values. It is divided into two main parts: Calculation steps for temperature and seepage pressure compensation values Temperature compensation value calculation Control equation: Solve the heat conduction equation (including heat source terms): in, ; Compensation algorithm: 1. Extract the temperature field from the finite element results 2. Calculate thermal expansion strain is the coefficient of thermal expansion.

[0052] 3. Modify the material stiffness matrix based on strain , update the stress field .

[0053] Calculation of seepage pressure compensation value Governing equations: Combining Darcy's law and the mass conservation equation: in, .

[0054] Compensation algorithm: 1. Extract pressure distribution from seepage field results .

[0055] 2. Calculate effective stress (Terzaghi effective stress principle).

[0056] in, .

[0057] 3. If non-Darcy flow exists, the permeability needs to be updated iteratively (Reynolds number correction).

[0058] in, ; ; ; .

[0059] Coupled iterative process Sequential coupling (weak coupling): First solve the temperature field and transfer the result to the seepage field as a heat source term.

[0060] Solve the seepage field, update the pressure distribution and then feed it back to the temperature field (such as the influence of fluid convection heat transfer).

[0061] Repeat the iteration until the temperature and pressure changes are both less than the set threshold (e.g. (ΔT < 0.1K, Δ p < 1Pa).

[0062] Technical effects: High accuracy: Directly measure the pipe wall strain, avoiding the inclination angle conversion error of traditional methods, with an accuracy of up to 0.1mm. Strong anti-interference: The pipe-slurry consolidation body isolates external disturbances (such as rainfall and construction vibration) and provides high data stability. Three-dimensional monitoring: Two sets of multi-directional strain gauges simultaneously acquire information on the sliding body's lateral, longitudinal, and torsional deformations. Temperature and seepage pressure data are collected simultaneously, and a finite element model is then constructed that includes the temperature, seepage, and stress-strain fields. Finally, the data processing unit dynamically calculates temperature and seepage pressure compensation values, correcting displacement results in real time. The resulting displacement-depth curve is then output after eliminating environmental interference.

[0063] Technology comparison: Table 1 index Traditional inclinometer Stress-strain observation method Measurement principle Indirect calculation of displacement by inclination Direct strain inversion Data Dimensions Unidirectional horizontal displacement Multi-directional 3D deformation Interference immunity Susceptible to vibration and temperature Tube-slurry consolidation isolates external interference and considers the influence of temperature and seepage field cost High (mechanical components + manual operation) Low (electronic sensing + automation) Applicable Scenarios Shallow landslide, low precision requirements Deep sliding body, high-precision three-dimensional monitoring requirements It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0064] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0065] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0066] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0067] In addition, the functional units in the various embodiments of the application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software program modules.

[0068] If the integrated unit is implemented in the form of a software program module and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a memory and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, magnetic disk, or optical disk, etc., various media that can store program code.

[0069] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable memory, which may include: a flash drive, a read-only memory, a random access memory, a magnetic disk or an optical disk, etc.

[0070] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of the present application. At the same time, for those skilled in the art, according to the idea of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A deep hole displacement automatic observation device based on stress and strain measurement, characterized in that: include: Observation tube, buried vertically in the borehole; A plurality of strain gauges are provided on the outer wall of the observation tube for real-time collection of axial strain and hoop strain data at different depths and directions; a data acquisition module, configured with a wireless transmission module and connected to the strain gauge via the wireless transmission module; Data processing unit, with built-in displacement integration algorithm and finite element model, used to calculate the displacement of the sliding body and the three-dimensional deformation field; The monitoring terminal receives and displays displacement results and warning information.

2. The deep hole displacement automatic observation device based on stress and strain measurement according to claim 1 is characterized in that: The plurality of strain gauges are axially spaced apart along the outer wall of the observation tube and symmetrically distributed along the circumferential direction.

3. The deep hole displacement automatic observation device based on stress and strain measurement according to claim 1 is characterized in that: Also includes: The temperature sensor and the osmometer are both fixed on the outer wall of the observation tube and are used to synchronously collect deep hole environmental temperature and seepage pressure data.

4. The deep hole displacement automatic observation device based on stress and strain measurement according to claim 3 is characterized in that: The data processing unit is equipped with a dynamic compensation module to correct the hoop strain data based on the thermometer seepage pressure data.

5. The deep hole displacement automatic observation device based on stress and strain measurement according to claim 3 is characterized in that: The wireless transmission module is a 4G / 5G communication module, which is used for remote real-time data transmission.

6. A deep hole displacement automatic observation method based on stress and strain measurement, characterized in that: An automatic deep hole displacement observation device based on stress-strain measurement according to any one of claims 1 to 5, comprising: An observation tube is installed in the deep hole, and a plurality of strain gauges are arranged axially at intervals along the outer wall of the observation tube; Real-time collection of axial strain and hoop strain data; Based on the axial strain and hoop strain data, combined with the elastic modulus and Poisson's ratio of the observed pipe material, the pipe wall stress distribution at the corresponding depth is calculated; The deformation and sliding direction of the sliding body are inverted by the stress-strain relationship, and the displacement depth curve is generated by combining the displacement integration algorithm to determine the sliding surface position and three-dimensional deformation field.

7. The method for automatic observation of deep hole displacement based on stress-strain measurement according to claim 6, characterized in that: Also includes: Synchronously collect temperature data and seepage pressure data of deep hole environment; Establishing a finite element model based on the temperature data, seepage pressure data, and strain data; Based on the finite element model, the hoop strain data is temperature compensated and the seepage pressure is corrected to output the sliding body displacement result.

8. The method for automatic observation of deep hole displacement based on stress-strain measurement according to claim 6, characterized in that: Also includes: The collected strain data is subjected to noise filtering and zero point calibration.

9. The method for automatic observation of deep hole displacement based on stress-strain measurement according to claim 6, characterized in that: The sliding surface position is determined by strain mutation points in different directions at the same depth, and the sliding direction is determined by the difference in strain direction.

10. The method for automatic observation of deep hole displacement based on stress-strain measurement according to claim 6, characterized in that: The displacement integration algorithm includes: in, For the The depth of each sensor; is the distance between adjacent sensors; K is the number of sensors; For the The depth of the sensor.

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