Visual dynamic monitoring device and method for water level of deep foundation pit

Abstract

The application relates to the technical field of liquid liquid level measurement, in particular to a deep foundation pit water level visual dynamic monitoring device and method, which generates a foundation pit three-dimensional model, collects water level height, pressure data and inclination angle data, calibrates the pressure data according to the offset angle, obtains the pressure data, sets water density, a linear attenuation coefficient and an actual total water level height in the deep foundation pit as parameters, respectively constructs a density attenuation model and a pressure integral equation according to the parameters, substitutes the density attenuation model and pressure data of all pressure sensors at the same collection time into the pressure integral equation, establishes a target function according to the corrected pressure values of all pressure sensors, inverses the pressure integral equation by using a least square method, and obtains the value of the actual total water level height in the deep foundation pit; and according to the actual total water level height in the deep foundation pit and the foundation pit three-dimensional model, the visual dynamic monitoring of the deep foundation pit water level is realized. The application can improve the accuracy of deep foundation pit water level monitoring.

Description

Technical Field

[0001] This application relates to the field of liquid level measurement technology, specifically to a visual dynamic monitoring device and method for deep foundation pit water level. Background Technology

[0002] During deep foundation pit construction, abnormal water level changes can lead to safety accidents such as pit collapse and settlement of surrounding buildings. Visual dynamic monitoring of deep foundation pit water levels allows for real-time monitoring of water level changes, early warning of anomalies, and helps assess the stability of the support structure.

[0003] When measuring the water level in deep foundation pits, silt deposition occurs within the pit, causing varying water densities at different depths—the density increases closer to the bottom. Directly using the ratio of pressure data collected at different depths to water level heights to determine the water level, relying solely on the lower density of the upper water layer, will result in overestimation of the water level. Conversely, using only the higher density of the lower water layer will lead to underestimation, resulting in inaccurate deep foundation pit water level monitoring. Therefore, a more accurate method for monitoring deep foundation pit water levels is needed. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a visual dynamic monitoring device and method for deep foundation pit water levels, and the specific technical solution adopted is as follows: In a first aspect, one embodiment of this application provides a method for visually and dynamically monitoring the water level in deep foundation pits, the method comprising the following steps: A 3D model of the foundation pit was generated, and water level, pressure, and tilt data were collected from pressure sensors at different heights at different collection times. Water density, linear attenuation coefficient, and actual total water level in the deep foundation pit are set as parameters. A density attenuation model and a pressure integral equation are constructed based on the parameters. The density attenuation model can calculate the density of water at different water levels, and the pressure integral equation can calculate the corrected pressure value of the pressure sensor. The density attenuation model and the pressure data of all pressure sensors at the same acquisition time are substituted into the pressure integral equation. An objective function is established based on the corrected pressure values ​​of all pressure sensors. The least squares method is used to invert the pressure integral equation to obtain the value of the actual total water level in the deep foundation pit at the same acquisition time. Based on the actual total water level in the deep foundation pit and the three-dimensional model of the pit, the water level in the deep foundation pit can be visualized and dynamically monitored.

[0005] Furthermore, the three-dimensional model of the foundation pit is a BIM model of a deep foundation pit.

[0006] Furthermore, the specific expression for the density decay model is as follows: in, Represents the first deep foundation pit The water level where the pressure sensor is located The density of water at that location; Represents the first deep foundation pit A pressure sensor measures the water level in the deep foundation pit. , This indicates the actual total water level height within the deep foundation pit; Represents the water density at the bottom of the deep foundation pit; This represents the linear attenuation coefficient.

[0007] Furthermore, the water level height is: The difference between the height of the pressure sensor inside the deep pit and the height of the water bottom.

[0008] Furthermore, the expression for the pressure integral equation is as follows: in, Indicates the first Pressure data from a pressure sensor; Represents gravitational acceleration; Indicates based on water level height And the integration interval is The integral; Indicates the water level height in the deep foundation pit The density of the water at that location.

[0009] The water level in the deep foundation pit The specific expression for the density of water at that location is: .

[0010] Furthermore, the objective function is: The sum of squares of the differences between the calibrated pressure value and the estimated pressure value of all pressure sensors.

[0011] Furthermore, the pressure estimate is obtained by calculating using a pressure formula.

[0012] Furthermore, the specific steps for achieving visualized dynamic monitoring of the water level in the deep foundation pit based on the actual total water level and the three-dimensional model of the pit are as follows: If the actual total water level in the deep foundation pit is greater than the warning value for the deep foundation pit water level, an early warning will be issued.

[0013] Secondly, another embodiment of this application provides a visual dynamic monitoring device for deep foundation pit water level, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the above-described visual dynamic monitoring method for deep foundation pit water level.

[0014] The embodiments of this application have at least the following beneficial effects: This application first considers that ground vibrations during deep foundation pit construction can easily cause soil displacement within the pit, potentially shifting the pressure sensor's pressure direction. This could lead to collected pressure data being lower than the actual pressure value and the water level in the deep foundation pit being lower than expected. The application calibrates the pressure data based on the offset angle to obtain pressure data from the pressure sensor at the same acquisition time, avoiding the problem of under-collected pressure data affecting the monitoring of the deep foundation pit water level. Due to the influence of silt and debris within the deep foundation pit, the water density varies at different depths. A density attenuation model is constructed to represent the water density at different levels. By integrating the pressure values, a pressure integral equation is constructed to represent the pressure data from different pressure sensors. The density attenuation model is then substituted into the pressure integral equation. The integral is calculated to simplify the pressure integral equation and demonstrate the correlation between pressure data and water density distribution and water level, providing a theoretical basis for subsequent inversion solutions. Furthermore, pressure data from all pressure sensors at the same acquisition time are substituted into the pressure integral equation, and an objective function is established based on the corrected pressure values ​​of all pressure sensors. The least squares method is used to invert the pressure integral equation to obtain the actual total water level in the deep foundation pit at the same acquisition time. Finally, based on the actual total water level in the deep foundation pit and the three-dimensional model of the pit, visualized dynamic monitoring of the deep foundation pit water level is achieved, solving the problem of different water densities in different water levels affecting the accuracy of deep foundation pit water level monitoring and improving the accuracy of deep foundation pit water level monitoring. Attached Figure Description

[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A flowchart illustrating the steps of a method for visually and dynamically monitoring the water level in a deep foundation pit, as provided in one embodiment of this application. Detailed Implementation

[0017] To further illustrate the technical means and effects adopted by this application to achieve the intended purpose of the invention, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of the visual dynamic monitoring device and method for deep foundation pit water levels proposed in this application. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0019] The following description, in conjunction with the accompanying drawings, details the specific scheme of the visualization and dynamic monitoring device and method for deep foundation pit water level provided in this application.

[0020] Please see Figure 1 The diagram illustrates a flowchart of a method for visually and dynamically monitoring the water level in a deep foundation pit according to an embodiment of this application. The method includes the following steps: Step S001: Generate a three-dimensional model of the foundation pit and collect water level, pressure, and tilt data from pressure sensors at different heights at different collection times.

[0021] After the deep foundation pit is excavated, pressure sensors are arranged in layers at 1-meter intervals along the vertical height of the sidewall of the deep foundation pit. They are fixed with expansion bolts and flexible sealant to ensure that there are no gaps between the pressure sensors and the soil. The pressure surface of each pressure sensor is calibrated with an inclinometer so that it is aligned with the pressure direction. Each pressure sensor has a built-in MEMS inclinometer. The inclinometer can reflect the offset posture of the pressure sensor. For example, if the soil displacement causes the sensor to tilt or the pressure direction to shift.

[0022] Use a pressure sensor to collect pressure data, tilt data, and the time of acquisition at the pressure sensor location.

[0023] Understandably, it is necessary to record the position of the pressure sensors when they are deployed, and to calculate the difference between the height of each pressure sensor in the deep foundation pit and the height of the water bottom based on the position of the pressure sensors, the height of the horizontal plane in the deep foundation pit, and the height of the water bottom in the deep foundation pit. This difference is recorded as the water level height of the pressure sensor.

[0024] Input the deep foundation pit drawings, support structure, surrounding conditions, and sensor information into AutoCAD. Remove redundant information such as annotations and auxiliary lines from the deep foundation pit drawings to obtain a DWG base map. Import the DWG base map into the foundation pit plan CAD drawing. Use the Revit extrusion tool to generate a 3D model of the foundation pit according to the sectional depth. This 3D model is the BIM model of the deep foundation pit.

[0025] A programmable logic controller (PLC) is used to collect pressure and tilt data from each pressure sensor at the same time. A LoRa module, such as the SX1278, is used for wireless transmission of the collection time, pressure data, and tilt data. In this embodiment, the transmission frequency is set to 433MHz. When the transmission power is 20dBm, the underground penetration distance is approximately 500 meters. During transmission, the AES-128 encryption algorithm is used to encrypt the collection time, pressure data, and tilt data to prevent data leakage or tampering. The transmitted pressure data and tilt data are then stored in the system's database.

[0026] The use of AutoCAD tools, Revit extrusion tools, programmable logic controllers (PLCs), LoRa modules, and AES-128 encryption algorithms are all well-known technologies and will not be elaborated further.

[0027] At this point, the pressure data of each pressure sensor at each acquisition time has been obtained.

[0028] Step S002: Set water density, linear attenuation coefficient, and actual total water level in the deep foundation pit as parameters. Construct a density attenuation model and a pressure integral equation based on the parameters. The density attenuation model can calculate the density of water at different water levels, and the pressure integral equation can calculate the corrected pressure value of the pressure sensor. Substitute the density attenuation model and the pressure data of all pressure sensors at the same acquisition time into the pressure integral equation. Establish an objective function based on the corrected pressure values ​​of all pressure sensors. Use the least squares method to invert the pressure integral equation and obtain the value of the actual total water level in the deep foundation pit at the same acquisition time.

[0029] Deep foundation pits are typically covered with a large amount of silt and debris. When rainwater flows into the pit, it washes away this silt, causing it to move and making the water turbid. Simultaneously, the silt gradually settles due to gravity, resulting in varying water densities at different depths within the pit; the density increases closer to the bottom. Directly using the ratio of pressure data collected at different depths to water level height to determine the water level, relying solely on the lower density of the upper water layer, will lead to overestimation of the water level. Conversely, using only the higher density of the lower water layer will result in underestimation, leading to inaccurate water level monitoring. Therefore, it is necessary to monitor the water level of deep foundation pits based on the actual density of different water layers.

[0030] Simultaneously, due to natural settlement, the water density at the same depth remains stable. When the particle settling rate equals the diffusion rate caused by water flow disturbance, i.e., when settlement reaches dynamic equilibrium, and if the water flow within the pit is stable, with no strong pumping or external water inflow, the silt density exhibits a uniform gradient with the water level. At this point, the concentration change per unit depth of silt is essentially constant, and the density decay in the vertical upward direction of the water flow within the deep pit conforms to linear decay characteristics. When settlement reaches dynamic equilibrium, if the water flow within the pit is subject to significant disturbance, such as turbulence caused by pumping, uneven silt particle size with large particles settling quickly and small particles diffusing widely, or stratified deposition, the density decay in the vertical upward direction of the water flow within the deep pit conforms to nonlinear decay characteristics, generally exhibiting exponential or power-law decay characteristics.

[0031] It should be noted that this application only analyzes cases where at least three pressure sensor locations are effectively immersed in water to ensure the validity of the analysis.

[0032] This embodiment uses linear decay characteristics as an example to construct a density decay model and calculate the density of water at different water levels. It is understood that the construction of density decay models with exponential decay and power function decay is similar and will not be elaborated further.

[0033] in, Represents the first deep foundation pit The water level where the pressure sensor is located The density of water at that location; Represents the first deep foundation pit A pressure sensor measures the water level in the deep foundation pit. , This represents the actual total water level height inside the deep foundation pit, which is the difference between the height of the horizontal plane inside the deep foundation pit and the height of the bottom of the water. Represents the water density at the bottom of the deep foundation pit; This represents the linear attenuation coefficient.

[0034] The linear decay coefficient is used to evaluate the rate at which the water density in a deep foundation pit decreases as the water level rises. The lower the water density at a given water level in the deep foundation pit, the closer that location is to the water surface within the pit, and the lower the water density.

[0035] Construct a pressure integral equation to calculate the corrected pressure value of the pressure sensor.

[0036] in, Indicates the first Pressure data from a pressure sensor; Indicates the water level height in the deep foundation pit The density of water at that location; Indicates the linear attenuation coefficient; Represents the water density at the bottom of the deep foundation pit; Represents the first deep foundation pit A pressure sensor measures the water level in the deep foundation pit. ; This indicates the actual total water level height within the deep foundation pit; This represents the acceleration due to gravity. In this embodiment, the value of the acceleration due to gravity is... ; Indicates based on water level height And the integration interval is The points.

[0037] Substituting the density decay model into the pressure integral equation and calculating the integral, the simplified pressure data from the pressure sensor is obtained as follows: The calculation of the calibrated pressure value of the pressure sensor demonstrates the correlation between pressure data and water density distribution and water level, which can provide a theoretical basis for subsequent inversion solutions.

[0038] The higher the calibration pressure value of the pressure sensor, the closer the pressure sensor is to the bottom of the deep foundation pit.

[0039] The objective function is to minimize the sum of the squares of the differences between the calibrated pressure values ​​and the estimated pressure values ​​of all pressure sensors. The pressure data of all pressure sensors at the same acquisition time are substituted into the pressure integral equation, and the least squares method is used to invert the pressure integral equation. The values ​​of water density at the bottom of the deep foundation pit, linear attenuation coefficient, and actual total water level in the deep foundation pit when the objective function is minimized are taken as the optimal values ​​of the corresponding parameters at the same acquisition time. Based on the optimal values, the water density at the water level height of each pressure sensor is calculated and recorded as the optimal water density at the corresponding pressure sensor water level height.

[0040] The pressure estimate is calculated based on the pressure integral equation; and the objective function is the sum of the squares of the corrected pressure value and the estimated pressure value.

[0041] Thus, the actual total water level height inside the deep foundation pit at each sampling moment is obtained.

[0042] Step S003: Based on the actual total water level in the deep foundation pit and the three-dimensional model of the foundation pit, realize the visualized dynamic monitoring of the water level in the deep foundation pit.

[0043] The actual total water level in the deep foundation pit is input into the 3D model of the pit, and a 3D water level surface is generated using the Kriging interpolation algorithm. A water level warning value for the deep foundation pit is set by someone skilled in the art based on actual construction needs. If the actual total water level in the deep foundation pit exceeds the warning value, a Revit fill pattern is used to dynamically color the water in the 3D model of the pit red, triggering an alarm mechanism to alert staff to take action.

[0044] By visualizing and providing early warnings of anomalies in the BIM model, water level risks can be presented intuitively and linked to the optimization of construction plans. This can effectively prevent safety accidents caused by water accumulation in the pit, reduce construction risks and economic losses. Among these technologies, Kriging interpolation algorithm, Revit fill patterns, and BIM visualization are all well-known and will not be elaborated further.

[0045] This enables the visualized dynamic monitoring of water levels in deep foundation pits.

[0046] This application also proposes a visual dynamic monitoring device for deep foundation pit water levels, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it performs the steps described above. Since the visual dynamic monitoring method for deep foundation pit water levels has been described in detail above, it will not be repeated here.

[0047] It should be noted that the order of the embodiments described above is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. Furthermore, specific embodiments of this specification have been described above. Additionally, the processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired results. In some implementations, multitasking and parallel processing are possible or may be advantageous.

[0048] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0049] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them; modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for visually and dynamically monitoring water levels in deep foundation pits, characterized in that, The method includes the following steps: Generate a 3D model of the foundation pit, and collect water level, pressure, and tilt data from pressure sensors at different heights at different collection times; Water density, linear attenuation coefficient, and actual total water level in the deep foundation pit are set as parameters. A density attenuation model and a pressure integral equation are constructed based on the parameters. The density attenuation model can calculate the density of water at different water levels, and the pressure integral equation can calculate the corrected pressure value of the pressure sensor. The density attenuation model and the pressure data of all pressure sensors at the same acquisition time are substituted into the pressure integral equation. An objective function is established based on the corrected pressure values ​​of all pressure sensors. The least squares method is used to invert the pressure integral equation to obtain the value of the actual total water level in the deep foundation pit at the same acquisition time. Based on the actual total water level in the deep foundation pit and the three-dimensional model of the foundation pit, the water level in the deep foundation pit can be visualized and dynamically monitored.

2. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 1, characterized in that, The three-dimensional model of the foundation pit is a BIM model of a deep foundation pit.

3. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 1, characterized in that, The specific expression for the density decay model is as follows: in, Represents the first deep foundation pit The water level where the pressure sensor is located The density of water at that location; Represents the first deep foundation pit A pressure sensor measures the water level in the deep foundation pit. , This indicates the actual total water level height within the deep foundation pit; Represents the water density at the bottom of the deep foundation pit; This represents the linear attenuation coefficient.

4. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 3, characterized in that, The water level is: The difference between the height of the pressure sensor inside the deep pit and the height of the water bottom.

5. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 3, characterized in that, The expression for the pressure integral equation is as follows: in, Indicates the first Pressure data from a pressure sensor; Represents gravitational acceleration; Indicates based on water level height And the integration interval is The integral; Indicates the water level height in the deep foundation pit The density of the water at that location.

6. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 5, characterized in that, The water level in the deep foundation pit The specific expression for the density of water at that location is: 。 7. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 1, characterized in that, The objective function is: The sum of squares of the differences between the calibrated pressure value and the estimated pressure value of all pressure sensors.

8. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 7, characterized in that, The pressure estimate is obtained by calculating the pressure formula.

9. The method for visual dynamic monitoring of water level in deep foundation pits according to claim 1, characterized in that, The specific steps for achieving visualized dynamic monitoring of the water level in a deep foundation pit based on the actual total water level and a three-dimensional model of the pit are as follows: If the actual total water level in the deep foundation pit is greater than the warning value for the deep foundation pit water level, an early warning will be issued.

10. A visual dynamic monitoring device for deep foundation pit water levels, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method for visual dynamic monitoring of deep foundation pit water level as described in any one of claims 1 to 9.

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