Water conservancy facility safety early warning method and system

Abstract

The invention provides a water conservancy facility safety early warning method and system, and relates to the technical field of water conservancy facility safety. The method comprises the steps of collecting hydraulic engineering parameters, hydrological data and hydraulic facility structure parameters; constructing a hydrodynamic mathematical model and carrying out stress analysis to obtain dynamic water pressure distribution data; screening an impact force concentration region, drawing a pressure contour map, and positioning a high-risk part to obtain a focus region; performing resilience method strength detection to obtain an actual compressive strength value; constructing a stamping model, calculating a theoretical deformation curve of the gate, and obtaining actual deformation data through laser ranging; and establishing a multi-level safety early warning index system for safety early warning. Through multidisciplinary model fusion, multi-source data collaboration and a dynamic early warning mechanism, accurate identification and efficient early warning of the water conservancy facility safety risk are realized, and powerful technical support is provided for water conservancy facility safety operation and maintenance under complex working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of water conservancy facility safety, and in particular to a water conservancy facility safety early warning method and a water conservancy facility safety early warning system. Background Art

[0002] As the core project for water resources regulation, flood prevention and disaster reduction, the safe and stable operation of water conservancy facilities is directly related to the safety of people’s lives and property and social and economic development.

[0003] However, the current field of water conservancy facility safety early warning still faces numerous technical bottlenecks, making it difficult to meet the demand for accurate early warnings under complex operating conditions. Existing early warning methods often rely on manual inspections and single-point monitoring, which suffer from limited coverage, data lags, and difficulty capturing the full range of characteristics. This is especially true under high water levels and strong currents, where data errors are large, easily leading to delayed early warnings or false alarms. Furthermore, the scientific nature of the early warning indicator system needs to be improved. Existing methods often use fixed thresholds to determine risk, failing to consider factors such as structural nonlinear behavior, resulting in low early warning accuracy. Summary of the Invention

[0004] The present invention provides a water conservancy facility safety early warning method and system, which are used to solve the defects in the prior art.

[0005] In one aspect, the present invention provides a water conservancy facility safety early warning method, comprising: Collect water conservancy project parameters, hydrological data and water conservancy facility structural parameters. The water conservancy facility structural parameters include the grade parameters of the concrete dam body and the material specifications of the gate.

[0006] According to the water conservancy project parameters and hydrological data, a hydrodynamic mathematical model based on the principles of fluid mechanics is constructed. The finite element method is used to analyze the stress of the water conservancy facility structure and obtain dynamic water pressure distribution data.

[0007] Based on the dynamic water pressure distribution data, the impact force concentrated areas are screened, and the pressure contour map is drawn to locate the high-risk areas to obtain the key areas of concern.

[0008] Rebound strength testing is carried out on key areas of concern, and the surface hardness data of the concrete is recorded and converted to obtain the actual compressive strength value.

[0009] A stamping model based on the gate material specifications is constructed, the theoretical deformation curve of the gate is calculated, and the actual deformation data is obtained through laser ranging.

[0010] Compare the actual compressive strength values ​​with the dynamic water pressure distribution data, analyze the degree of deviation between the actual deformation data and the theoretical deformation curve, and establish a multi-level safety early warning indicator system.

[0011] When the detection value exceeds the safety threshold, an early warning is triggered and an assessment report is generated containing the location and extent of the risk.

[0012] According to the water conservancy facility safety early warning method provided by the present invention, hydrological data includes water level, flow velocity, pressure and temperature. Water conservancy project parameters include reservoir capacity and dam geometric dimensions, and dam geometric dimensions include height, slope and top width.

[0013] According to a water conservancy facility safety early warning method provided by the present invention, the process of constructing a hydrodynamic mathematical model based on fluid mechanics principles includes: The area where the water conservancy facilities are located is divided into three-dimensional space to form a three-dimensional calculation grid, and the boundary range of the water area and water conservancy facilities is obtained.

[0014] Based on the Navier-Stokes equations and the continuity equation, combined with the parameters of the hydraulic project and the structural parameters of the hydraulic facilities, initial and boundary conditions are set. The initial conditions represent the flow state parameters, while the boundary conditions are the flow parameter restrictions within the water area and the hydraulic facility boundaries. Flow state parameters include flow velocity, direction, pressure, and density. Flow parameter restrictions include velocity, pressure, and flow rate limits at the boundaries.

[0015] The finite volume method is used to discretize the Navier-Stokes equations and the continuity equation, and the continuous water flow motion is converted into numerical calculations on discrete nodes. The continuous water flow motion is dynamically simulated to obtain a hydrodynamic mathematical model.

[0016] According to a water conservancy facility safety early warning method provided by the present invention, the process of obtaining dynamic water pressure distribution data includes: Construct a finite element model of the water conservancy facility structure, which includes the concrete dam body and gates.

[0017] The water pressure loads are calculated based on the hydrodynamic mathematical model and applied to the finite element model in the form of nodal forces.

[0018] The material constitutive relationship of the finite element model is defined according to the structural parameters of the water conservancy facilities, the stress concentration factor of the water conservancy facilities structure is calculated, and the load combination is formed by combining the water pressure load.

[0019] Combined with the load combination, the stress field and displacement field of the finite element model in the hydrodynamic mathematical model are solved by the time history analysis method to obtain the dynamic water pressure distribution data.

[0020] According to a water conservancy facility safety early warning method provided by the present invention, the process of screening the impact force concentrated area includes: Based on the dynamic water pressure distribution data, the dynamic water pressure gradient of the water flow on the surface of the water conservancy facility structure is calculated, and the surface area of ​​the water conservancy facility structure where the dynamic water pressure gradient exceeds the preset threshold is marked as the potential impact force concentration area.

[0021] According to a water conservancy facility safety early warning method provided by the present invention, the process of obtaining the key focus area includes: The dynamic water pressure distribution data is interpolated onto a regular grid to form a continuous pressure data distribution.

[0022] The Kriging interpolation algorithm is used to process the continuous pressure data distribution and generate a continuous pressure field.

[0023] A closed curve is drawn for the continuous pressure field based on equally spaced pressure values ​​to form a pressure contour map.

[0024] Identify the contour-dense areas and high-value areas in the pressure contour map, and mark the key areas of concern in combination with the stress concentration factor.

[0025] According to a water conservancy facility safety early warning method provided by the present invention, the process of obtaining the actual compressive strength value includes: Select measurement areas within the key focus area and evenly arrange N measurement points in each measurement area.

[0026] Use a standard rebound hammer to test perpendicular to the concrete surface and record the rebound value at each measuring point.

[0027] Abnormal data including abnormal carbonization depth points were eliminated and the average rebound value of the measurement area was calculated.

[0028] The carbonation depth of concrete was measured and the thickness of the carbonization layer was determined by the phenolphthalein reagent colorimetric method.

[0029] The compressive strength of concrete is obtained by comparing and converting the average rebound value of the measured area and the carbonation depth of the concrete with the strength curve.

[0030] According to a water conservancy facility safety early warning method provided by the present invention, the process of constructing a stamping model based on gate material specifications includes: Determine the geometric parameters and load conditions of the gate. The geometric parameters include length, width, thickness and support method. The load conditions include static water pressure, dynamic water pressure and wave load.

[0031] Select a material constitutive model that matches the gate material and set the gate material parameters, including elastic modulus, Poisson's ratio, yield strength, and ultimate strength.

[0032] Define the contact conditions of the gate, which include friction contact between the gate and the gate slot.

[0033] Apply boundary constraints and load distribution to simulate the stress state of the gate under different working conditions and complete the construction of the stamping model based on the gate material specifications.

[0034] According to a water conservancy facility safety early warning method provided by the present invention, the process of calculating the theoretical deformation curve of the gate includes: Based on the principle of material mechanics and combined with the stamping model, the deflection differential equation of the gate under water pressure is established.

[0035] Considering the constraints and load distribution of the gate, the double-moment theory is used to solve the flexural differential equation. The constraints include simply supported and fixed supported, and the load distribution includes uniformly distributed load and concentrated load.

[0036] Based on the solution results, the maximum deflection and stress distribution of the gate under different water levels are calculated.

[0037] Analyze the influence of the nonlinear behavior of the gate on the deformation, including the large deformation effect.

[0038] Based on the calculation results at different water levels, the theoretical deformation curves of the gate under different working conditions are generated.

[0039] On the other hand, the present invention also provides a water conservancy facility safety early warning system, comprising: The data acquisition module is used to collect water conservancy project parameters, hydrological data and water conservancy facility structural parameters. The water conservancy facility structural parameters include the label parameters of the concrete dam body and the gate material specifications.

[0040] The water pressure distribution calculation module is used to construct a hydrodynamic mathematical model based on the principles of fluid mechanics according to water conservancy project parameters and hydrological data, and use the finite element method to perform stress analysis on the structure of water conservancy facilities to obtain dynamic water pressure distribution data.

[0041] The key area screening module is used to screen the impact force concentration areas based on the dynamic water pressure distribution data, draw pressure contour maps to locate high-risk areas, and obtain key areas of concern.

[0042] The compressive strength calculation module is used to perform rebound strength testing on key areas of concern, record the concrete surface hardness data and convert it to obtain the actual compressive strength value.

[0043] The deformation data acquisition module is used to build a stamping model based on the gate material specifications, calculate the theoretical deformation curve of the gate, and obtain actual deformation data through laser ranging.

[0044] The comparison and warning module is used to compare the actual compressive strength value with the dynamic water pressure distribution data, and analyze the degree of deviation between the actual deformation data and the theoretical deformation curve, establish a multi-level safety warning indicator system, trigger an early warning when the detection value exceeds the safety threshold, and generate an assessment report including the risk location and degree.

[0045] The present invention provides a water conservancy facility safety early warning method and system, which realizes the dynamic correlation from water flow load to structural response by integrating hydrodynamic mathematical models and finite element structural analysis. Through three-dimensional computational grid division and Kriging interpolation technology, the distribution characteristics of water pressure on the surface of water conservancy facilities are accurately portrayed, and high-risk areas are identified in combination with stress concentration coefficients, overcoming the limitations of traditional single-point monitoring. With water conservancy project parameters, hydrological data, and structural parameters as the core, a complete closed loop for water conservancy facility safety early warning is constructed. By discretizing fluid mechanics equations through the finite volume method, hydrological data is converted into dynamic loads that can directly act on the structural model; using the rebound method and laser ranging technology, non-destructive testing of concrete strength and gate deformation is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 This is a flow chart of a water conservancy facility safety early warning method provided by an embodiment of the present invention; Figure 2 It is a structural diagram of a water conservancy facility safety early warning system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0049] The following combination Figure 1-Figure 2 The present invention describes a water conservancy facility safety early warning method and system.

[0050] Figure 1 It is a flow chart of a water conservancy facility safety early warning method provided by an embodiment of the present invention.

[0051] like Figure 1 As shown, an embodiment of the present invention provides a water conservancy facility safety early warning method and system, the execution subject can be a water conservancy facility safety early warning method, the method includes: Collect water conservancy project parameters, hydrological data and water conservancy facility structural parameters. The water conservancy facility structural parameters include the grade parameters of the concrete dam body and the material specifications of the gate.

[0052] Hydrological data includes water level, flow rate, pressure, and temperature. Water conservancy project parameters include reservoir capacity and dam geometry, which includes height, slope, and crest width.

[0053] Collection of structural parameters of water conservancy facilities: Focus on two core structures: concrete dam body and gate. The grade parameters of the concrete dam body need to be obtained by consulting construction files and on-site sampling and testing, including concrete design strength grade (such as C25, C30), impermeability grade (such as P6, P8) and elastic modulus, etc.; the gate material specifications need to record the gate main material (such as carbon steel Q235, stainless steel 304), thickness and welding process parameters to ensure that the parameters cover the key stress properties of the structure.

[0054] Hydrological data collection: Using a combination of automated monitoring equipment and manual inspections, we collect four types of data: water level, flow rate, pressure, and temperature. Water level is monitored in real time using ultrasonic water level gauges installed at different elevations on the dam body, with a sampling frequency of once every five minutes and an accuracy of ±0.01m. Doppler flow meters are used to measure flow rate at three monitoring points evenly distributed across the water section, obtaining the average flow rate across the section with an error of no more than 5%. Pressure is collected using pressure sensors embedded on the waterfront of the dam body, covering the water level fluctuation zone and key areas at the dam bottom. Temperature is monitored using thermocouple sensors on the water and dam surface, with the data transmitted synchronously to the central control system.

[0055] Water conservancy project parameter collection: The focus is on reservoir capacity and dam geometry. Reservoir capacity is obtained using a reservoir capacity curve, generated from dam completion survey data, covering the full range from dead water level to the verified flood level. Dam geometry is obtained through field measurements using a total station, including dam height (vertical distance from dam crest to dam bottom), slope (ratio of vertical height to horizontal distance of the dam slope), and crest width (horizontal width at the dam crest centerline). The measurement error is controlled within ±0.05m to ensure the geometric accuracy of subsequent model construction.

[0056] According to the water conservancy project parameters and hydrological data, a hydrodynamic mathematical model based on the principles of fluid mechanics is constructed. The finite element method is used to analyze the stress of the water conservancy facility structure and obtain dynamic water pressure distribution data.

[0057] The process of constructing a hydrodynamic mathematical model based on fluid mechanics principles includes: The area where the water conservancy facilities are located is divided into three-dimensional space to form a three-dimensional calculation grid, and the boundary range of the water area and water conservancy facilities is obtained.

[0058] An unstructured grid was used to partition the three-dimensional space surrounding the water conservancy facilities. The mesh unit type was tetrahedron, and its size was dynamically adjusted based on the complexity of the structure. The mesh size on the surfaces of structures such as dams and gates was set to 0.5m × 0.5m × 0.5m, while the mesh size in open areas was increased to 5m × 5m × 5m. A mesh quality check (distortion ratio < 0.8) was performed to ensure computational stability. The boundaries of the water area and water conservancy facilities were ultimately determined, with the boundary lines being fitted to the actual terrain using polylines.

[0059] Based on the Navier-Stokes equations and the continuity equation, combined with the parameters of the hydraulic engineering project and the structural parameters of the hydraulic facilities, initial and boundary conditions are set. The initial conditions represent the water flow state parameters, and the boundary conditions are the water flow parameter restrictions within the water area and the boundaries of the hydraulic facilities. Water flow state parameters include flow velocity, flow direction, water flow pressure, and water flow density. Water flow parameter restrictions include speed restrictions, pressure restrictions, and flow restrictions at the boundaries. The inlet boundary is set as the flow boundary (determined by the inflow flow in the hydrological data), the outlet boundary is set as free outflow, the solid wall boundary (dam body, gate surface) is set to a no-slip condition (speed limit is 0), the pressure limit is the local atmospheric pressure, and the flow limit is set with an upper limit based on the flood discharge capacity.

[0060] The Navier-Stokes equations are used to describe the motion of fluids, and the formula is expressed as:

[0061] The continuity equation is used to describe the law of conservation of mass of a fluid, and the formula is expressed as:

[0062] Where, represents the water density, represents the velocity vector, p represents the pressure, represents the fluid dynamic viscosity coefficient, Represents body force.

[0063] The finite volume method is used to discretize the Navier-Stokes equations and the continuity equation, and the continuous water flow motion is converted into numerical calculations on discrete nodes. The continuous water flow motion is dynamically simulated to obtain a hydrodynamic mathematical model.

[0064] The calculation area is divided into a series of control volumes. For each control volume integral equation, the volume integral is converted into the surface integral by Gauss's theorem to obtain the discrete equation, which is expressed as follows:

[0065] Where, represents the control volume interface flux, represents the water density, and V is the volume of the control body.

[0066] The first-order upwind scheme is used to calculate the convection term, and the central difference scheme is used to calculate the diffusion term. The pressure-velocity coupling problem is solved by the SIMPLE algorithm. The time step is set to 0.1s, and a dynamic numerical simulation of the continuous water flow motion is performed. The iterative calculation is performed until convergence, and finally a hydrodynamic mathematical model is obtained, which can output the water pressure and velocity distribution at any time.

[0067] The process of obtaining dynamic water pressure distribution data includes: Construct a finite element model of the water conservancy facility structure, which includes the concrete dam body and gates.

[0068] Based on the structural parameters of the water conservancy facility, a finite element model of the concrete dam and gates was constructed using ANSYS software. The concrete dam body was constructed using solid elements (SOLID65) with a unit size of 1m × 1m × 1m to account for the differences in material properties during the layered casting of the dam body. The gates were constructed using shell elements (SHELL181), with a unit thickness consistent with the actual gate thickness (e.g., 0.05m). The model had approximately 500,000 nodes to ensure accurate representation of structural details such as the dam corridor and gate supports.

[0069] The water pressure load is calculated according to the hydrodynamic mathematical model and applied to the water-facing nodes of the finite element model in the form of nodal force in a time series. The load magnitude is dynamically updated as the water level changes.

[0070] The material constitutive relationship of the finite element model is defined according to the structural parameters of the water conservancy facilities.

[0071] The concrete dam body adopts an elastic-plastic model, and its constitutive relationship is:

[0072] Where, is stress, is the elastic modulus of the concrete dam body, is the total strain, is the plastic strain; the gate adopts a linear elastic model, and the constitutive relationship is , E takes , Poisson's ratio 0.3.

[0073] Calculate the stress concentration factor of the water conservancy facility structure. The stress concentration factor is obtained by the ratio of the maximum stress to the nominal stress in the finite element model. Combined with the water pressure load, a load combination is formed.

[0074] Combined with the load combination, the stress field and displacement field of the finite element model in the hydrodynamic mathematical model are solved by the time history analysis method to obtain the dynamic water pressure distribution data.

[0075] Based on the dynamic water pressure distribution data, the impact force concentrated areas are screened, and the pressure contour map is drawn to locate the high-risk areas to obtain the key areas of concern.

[0076] The process of screening impact concentration areas includes: Based on the dynamic water pressure distribution data, the dynamic water pressure gradient of the water flow on the surface of the water conservancy facility structure is calculated, and the surface area of ​​the water conservancy facility structure where the dynamic water pressure gradient exceeds the preset threshold is marked as the potential impact force concentration area.

[0077] According to the dynamic water pressure distribution data, the water pressure value of each node on the surface of the water conservancy facility structure is extracted, and the dynamic water pressure gradient is calculated using the spatial finite difference method. Specifically: in the three-dimensional coordinate system, for the water pressure value p(x,y,z) of any node (x,y,z), the partial derivatives in the x, y, and z directions are calculated respectively. , and then the dynamic water pressure gradient G of the node is obtained by vector synthesis. The calculation formula is:

[0078] The partial derivative is calculated by the ratio of the water pressure difference between adjacent nodes to the spatial distance.

[0079] A dynamic water pressure gradient threshold is preset, which is determined according to the allowable material stress in the structural parameters of the water conservancy facility: for the concrete dam body, combined with its grade parameters (such as the axial compressive strength of C30 concrete is 20.1MPa), a safety factor of 1.5 is taken, and the calculated gradient threshold is 500Pa / m; for the gate, based on its material specifications (such as the yield strength of Q235 steel is 235MPa), a safety factor of 2.0 is taken, and the gradient threshold is set to 800Pa / m.

[0080] The surface area of ​​the water conservancy facility structure where the dynamic water pressure gradient G exceeds the corresponding threshold is marked as the potential impact force concentration area.

[0081] Call the flow field data output by the hydrodynamic mathematical model to analyze the flow pattern in the area where potential impact force is concentrated: If there is a vortex in the area, the area is prone to local high pressure due to the impact of the vortex and is included in the screening results; If the area is on the jet path (the angle between the flow direction and the structure surface is <30°, and the flow velocity is >2m / s), the jet impact force will aggravate the stress on the structure and will be included in the screening results.

[0082] Based on the above analysis, the impact force concentration area is finally determined. This area must simultaneously meet the two conditions of the dynamic water pressure gradient exceeding the threshold and the existence of a strong impact flow state.

[0083] The process of arriving at the focus areas includes: The dynamic water pressure distribution data is interpolated onto a regular grid to form a continuous pressure data distribution.

[0084] The grid size is set to 1m×1m, which is determined according to the geometric dimensions of the dam in the water conservancy project parameters (for example, when the top width of the dam is 10m, the grid size is 1 / 10 of the top width to ensure accuracy). Linear interpolation is used to fill the blank points in the grid. For nodes in the impact force concentration area, the interpolation weight is increased by 20% to highlight their pressure characteristics, ultimately forming a continuous pressure data distribution covering the entire surface of the water conservancy facility.

[0085] The Kriging interpolation algorithm is used to process the continuous pressure data distribution and generate a continuous pressure field.

[0086] Select the spherical variogram (suitable for the characteristic of pressure decay with distance in water conservancy projects) and set the range to 5m (determined based on 1 / 10 of the dam height); The interpolation parameters are adjusted through cross-validation to ensure that the interpolation error is less than 5% (that is, the deviation between the interpolation result and the original dynamic water pressure data is ≤5%). Finally, a smooth and realistic continuous pressure field is obtained, which can fully reflect the gradual characteristics of water pressure in space.

[0087] A closed curve is drawn for the continuous pressure field based on equally spaced pressure values ​​to form a pressure contour map.

[0088] The equally spaced pressure values ​​are determined based on the range of the dynamic water pressure distribution data. If the water pressure range is 0-10000Pa, each 1000Pa is set as an interval to ensure that the contour line density in high pressure areas (such as impact force concentrated areas) is sufficient; The contour3 function of MATLAB software is used to draw a three-dimensional contour map, where the color gradient of the contour lines corresponds to the pressure value (blue for low pressure and red for high pressure), and the line density reflects the rate of pressure change, providing an intuitive basis for subsequent feature recognition.

[0089] Identify the contour-dense areas and high-value areas in the pressure contour map, and mark the key areas of concern in combination with the stress concentration factor.

[0090] Contour-dense area: The contour spacing in this area is less than 2m, corresponding to a pressure gradient greater than 500Pa / m (consistent with the gradient threshold in the impact force concentration area), indicating that the pressure changes dramatically over a short distance, which can easily lead to local stress concentration. High-value area: The water pressure value in this area is greater than 1.2 times the design value (the design value is determined according to the flood control level in the water conservancy project parameters, such as the design water pressure corresponding to a 100-year flood), and it must contain at least 5 consecutive grid points to avoid interference from single-point outliers.

[0091] According to the calculated stress concentration factor K of the water conservancy facility structuret , perform secondary screening on the above feature areas: For the area with dense contour lines, if the K of the corresponding structural parts (such as dam body corners and gate support points) t >2.0 (according to the results of finite element analysis, this value is the critical value for structural damage), then it is marked as a high-risk candidate area; For high-value areas, if they overlap with the impact force concentration area, and the K t >1.5, it is marked as a high-risk candidate area.

[0092] The two types of candidate areas are combined and their intersection is taken as the final key focus area. This area must simultaneously meet the three conditions of significant pressure characteristics, structural stress concentration and strong impact of water flow, so as to lock the target for subsequent concrete strength testing and gate deformation analysis.

[0093] Conduct rebound strength testing on key areas of concern, record the concrete surface hardness data and convert it to obtain the actual compressive strength value. The process includes: Select measurement areas within the key focus area and evenly arrange N measurement points in each measurement area.

[0094] Use a standard rebound hammer to test perpendicular to the concrete surface and record the rebound value at each measuring point.

[0095] Abnormal data including abnormal carbonization depth points were eliminated and the average rebound value of the measurement area was calculated.

[0096] The carbonation depth of concrete was measured and the thickness of the carbonization layer was determined by the phenolphthalein reagent colorimetric method.

[0097] The compressive strength of concrete is obtained by comparing and converting the average rebound value of the measured area and the carbonation depth of the concrete with the strength curve.

[0098] When there is a difference between the structural conditions and the applicable conditions of the strength measurement curve, the core sampling method is used to correct the converted compressive strength.

[0099] In this embodiment, each measurement area is equipped with 16 rebound points, tested using a ZC3-A rebound hammer. During testing, the rebound hammer should always be perpendicular to the test surface and must not strike pores or gravel. If the hammer strikes pores or gravel, the hammer will not be counted towards the 16 points in each measurement area. Each measurement area has two surfaces, each with eight points. If a measurement area has only one surface, 16 points are required. Only one strike is allowed per measurement point. The measurement points should be evenly distributed across the measurement surface. The rebound value reading at each measurement point should be accurate to 1. The spacing between points should generally be no less than 20 mm, and the spacing between measurement points and the edge of the component or exposed rebar or ironwork should generally be no less than 50 mm. When testing with the rebound hammer, the instrument should be kept horizontal, and the side surface, facing the direction of concrete pouring, should be tested. If this requirement cannot be met, the test can be conducted in a non-horizontal position, or on the top or bottom surface, facing the direction of concrete pouring.

[0100] When the rebound hammer is used to test the concrete pouring side in the horizontal direction, the 3 maximum and 3 minimum values ​​should be removed from the 16 rebound values ​​in each measurement area, and the arithmetic mean of the remaining 10 rebound values ​​should be taken as the average rebound value of the measurement area, rounded to one decimal place. The calculation formula is:

[0101] Where, Indicates the average rebound value of the measurement area, calculated to 0.1; Represents the rebound value of the i-th measuring point.

[0102] Since the rebound strength curve is calculated based on the test data of the side of the concrete specimen tested by the rebound hammer in the horizontal direction, the measured rebound value needs to be corrected when the above conditions cannot be met during the test. First, the average rebound value of the test area is calculated based on the data of the concrete pouring side tested in the non-horizontal direction, and then the average rebound value of the test area is calculated based on the angle between the axis of the rebound hammer and the horizontal force direction. Find out the correction value and convert it into the average rebound value of the measuring area during horizontal testing.

[0103]

[0104] Where, It represents the average rebound value of the test area when the axis of the rebound hammer is at an angle to the horizontal force direction, calculated to 0.1; Indicates different test angles Rebound correction value, calculated to 0.1.

[0105] When the rebound hammer is used to test the concrete casting surface or bottom surface in the horizontal direction, the measured data should be used to calculate the average rebound value of the measuring area and then corrected according to the following formula.

[0106]

[0107] Where, Indicates the average rebound value of the measuring area when testing the concrete pouring surface or bottom surface in the horizontal direction; Represents the rebound value correction value of different casting surfaces, calculated to 0.1.

[0108] If the instrument is not horizontal during testing and the measuring area is not on the concrete pouring side, the rebound value should be corrected for angle first and then for the pouring surface.

[0109] After the rebound value is measured, the carbonization depth value should be measured at representative locations. The measurement points should not be less than 30% of the measurement area of ​​the component. The average value is taken as the carbonization depth value of each measurement area of ​​the component. When the range of carbonization depth values ​​is greater than 2.0mm, the carbonization depth value should be measured in each measurement area.

[0110] According to the Technical Specification for Testing Concrete Compressive Strength by Rebound Method JGJ / T23-2011, the estimated value of component concrete strength is determined by the following method.

[0111] When the number of measurement areas of a structure or component is less than 10:

[0112] Where, Indicates the estimated value of the concrete strength of the component, Indicates the converted value of concrete strength of the minimum measuring area in the component.

[0113] When the strength value of the structure or component measurement area is less than 10.0: .

[0114] When the number of measurement areas of a structure or component is not less than 10 or when testing is done in batches, the following formula should be used for calculation:

[0115]

[0116]

[0117] Where, Indicates the converted value of concrete strength in the component measurement area. Indicates the average value of the converted value of concrete strength in the component measurement area (MPa), It represents the standard deviation (MPa) of the converted value of concrete strength in the component measurement area, and n represents the number of structure or component measurement areas.

[0118] For components tested in batches, if the standard deviation of the concrete strength of the batch of components shows any of the following conditions, all the components shall be tested as individual components: When the average concrete strength of this batch of components is less than 25MPa: ; When the average concrete strength of this batch of components is not less than 25MPa: .

[0119] During testing, gate piers and other structures are examined as a single component. Core samples are obtained by drilling, typically to a depth of no more than 20 cm. The drill rig is moved to the coring location, securely positioned, and leveled. The water and power supply are connected, the motor is started, and the pressure handle is operated to slowly bring the drill bit into contact with the concrete surface. Drilling should be performed with extreme caution if the concrete surface is uneven. Once the drill bit is firmly seated in the groove, appropriate pressure can be applied. Cooling water should be maintained throughout the drilling process, ideally at a flow rate of 3 to 5 L / min. When the drill bit reaches the required core length, it is withdrawn to a distance of 20 to 30 mm from the concrete surface. Power and water are then turned off, and the drill bit is completely withdrawn from the concrete surface. After removing the drill rig, a curved steel drill with a tip is inserted into the annular groove of the core sample. The tip of the drill is struck with a hammer. The bending moment causes the bottom of the core sample to separate from the component. The core sample is then removed, promptly numbered, and its appearance and quality inspected. Records are kept and stored for future testing.

[0120] After indoor processing and cutting into cylindrical test blocks, the core samples are air-dried and then subjected to compressive strength test. The core samples are processed and cut into φ100mm×100mm standard cylindrical test blocks, and the ends are ground flat. The core sample failure load is measured on a press.

[0121] The strength conversion formula of the core sample is as follows:

[0122] Where, Indicates the converted value of the concrete strength of the core specimen (MPa), accurate to 0.1MPa; F indicates the maximum pressure of the core specimen compression test (N); Indicates the average diameter of the core sample (mm).

[0123] According to the specification, the minimum strength value of the core sample within a group is used as the representative compressive strength value for that group of core samples. This value is equivalent to the compressive strength of a standard 150cm×150cm×150cm test block of the same age. When correcting the compressive strength of core specimens for strength measured by rebound or other methods, the strength conversion value for standard-sized core specimens should be no fewer than six, and the number of small-diameter core samples should be appropriately increased. Core samples should be randomly selected from structural components using indirect testing methods. When the indirect testing method used is nondestructive testing, the core drilling location should coincide with the corresponding measurement area of ​​the indirect testing method.

[0124] A stamping model based on the gate material specifications is constructed, the theoretical deformation curve of the gate is calculated, and the actual deformation data is obtained through laser ranging.

[0125] The process of building a stamping model based on the gate material specifications includes: Determine the geometric parameters and load conditions of the gate. The geometric parameters include length, width, thickness and support method. The load conditions include static water pressure, dynamic water pressure and wave load.

[0126] The gate is scanned in three dimensions using a total station to obtain key parameters such as length, width, and thickness: the length is the maximum dimension of the gate along the direction of water flow (accurate to 0.01m), the width is the span of the gate perpendicular to the direction of water flow (such as the arc length projection of a curved gate), and the thickness is the actual thickness of the gate panel (the average value of three measuring points is taken); the support method is determined through on-site investigation and is divided into simply supported (only vertical displacement is restricted at both ends of the gate) and fixed supported (displacement and rotation are restricted at both ends of the gate), and the position coordinates of the support points are recorded (the distance relative to the edge of the gate).

[0127] The hydrostatic pressure is calculated based on the collected water level data according to the formula Calculate, where represents the hydrostatic pressure, is the water density, g is the acceleration of gravity, h is the vertical distance from the calculation point to the water surface, and it is linearly distributed along the height direction of the gate; the dynamic water pressure is extracted from the dynamic water pressure distribution data of each node on the gate surface, and organized into a load curve that changes with the water flow velocity in time series.

[0128] Select a material constitutive model that matches the gate material and set the gate material parameters, including elastic modulus, Poisson's ratio, yield strength, and ultimate strength.

[0129] Select the corresponding constitutive model according to the gate material specifications: if it is carbon steel (such as Q235), use the ideal elastic-plastic model (Hooke's law is satisfied before yielding, and the stress remains constant after yielding); if it is stainless steel (such as 304), use the kinematic hardening model (considering the yield surface translation under cyclic loading).

[0130] The elastic modulus is obtained through material mechanical property test. For carbon steel, , stainless steel , the error is controlled within ±5%; Poisson's ratio is obtained according to the gate material manual, and metal materials are usually taken as 0.3; yield strength and ultimate strength are determined according to the material specification, such as the yield strength of Q235 steel is 235MPa, and the ultimate strength is 375 to 500MPa, and the test temperature is recorded (the value at room temperature of 20℃).

[0131] Define the contact conditions of the gate, which include friction contact between the gate and the gate slot.

[0132] The contact unit in the finite element software is used to define the contact relationship between the gate and the gate slot. The contact type is Coulomb friction contact. The friction coefficient is determined according to the gate material (0.15~0.2 for steel-to-steel contact and 0.05~0.1 when the surface is coated with a lubricating layer). The contact stiffness is set to 1 / 10 of the material elastic modulus (to avoid calculation convergence problems).

[0133] Constraints are applied according to the support method: the simply supported end limits the displacement in the z direction (vertical), releasing the displacement in the x (length direction) and y (width direction) and the rotational freedom; the fixed end limits the displacement in the x, y, and z directions and the rotational freedom around the x and y axes to ensure that the constraints are consistent with the actual support status.

[0134] Apply boundary constraints and load distribution to simulate the stress state of the gate under different working conditions and complete the construction of the stamping model based on the gate material specifications.

[0135] The process of calculating the theoretical deformation curve of the gate includes: Based on the principle of material mechanics and combined with the stamping model, the deflection differential equation of the gate under water pressure is established, which is expressed as follows:

[0136] Where, is the elastic modulus in the material parameters, I is the moment of inertia of the gate section, w is the deflection along the length direction x, and q(x) is the distributed load in the load condition.

[0137] Considering the constraints and load distribution of the gate, the double-moment theory is used to solve the flexural differential equation. The constraints include simply supported and fixed supported, and the load distribution includes uniformly distributed load and concentrated load.

[0138] Based on the solution results, the maximum deflection and stress distribution of the gate under different water levels are calculated.

[0139] The double-moment theory is used to solve the equation. For uniformly distributed loads (such as hydrostatic pressure), the analytical solution is:

[0140] Where L is the length and q is the uniformly distributed load acting on the gate.

[0141] For concentrated loads (such as local water pressure at the midpoint of the gate), the analytical solution requires superimposing the deflection components caused by the concentrated force to ultimately obtain the theoretical deflection w(x) corresponding to different positions x.

[0142] Analyze the influence of the nonlinear behavior of the gate on the deformation, including the large deformation effect.

[0143] Based on the calculation results at different water levels, the theoretical deformation curves of the gate under different working conditions are generated.

[0144] Compare the actual compressive strength values ​​with the dynamic water pressure distribution data, analyze the degree of deviation between the actual deformation data and the theoretical deformation curve, and establish a multi-level safety early warning indicator system.

[0145] When the detection value exceeds the safety threshold, an early warning is triggered and an assessment report containing the location and extent of the risk is generated.

[0146] In summary, this embodiment provides a safety early warning method for water conservancy facilities. By integrating hydrodynamic mathematical models with finite element structural analysis, a dynamic correlation from water flow load to structural response is achieved. Through three-dimensional computational grid division and Kriging interpolation technology, the distribution characteristics of water pressure on the surface of water conservancy facilities are accurately portrayed, and high-risk areas are identified in combination with stress concentration coefficients, overcoming the limitations of traditional single-point monitoring. For example, the analysis of gate deformation not only considers static water pressure, but also incorporates dynamic factors such as dynamic water pressure and wave loads. By solving the flexural differential equation and nonlinear correction, the theoretical deformation curve is highly consistent with the actual working conditions, providing a reliable benchmark for deviation analysis.

[0147] The solution, centered around water conservancy project parameters, hydrological data, and structural parameters, establishes a complete closed-loop system for early warning of water conservancy facility safety. Using the finite volume method to discretize fluid dynamics equations, hydrological data is converted into dynamic loads that can be directly applied to the structural model. The rebound method and laser ranging technology enable nondestructive testing of concrete strength and gate deformation. The deep integration of multi-source data enables the early warning model to respond in real time to dynamic factors such as water level changes and material degradation, significantly enhancing the scientific nature of risk assessment.

[0148] Through automated data collection and batch model calculation, the traditional manual inspection cycle has been significantly shortened, significantly improving the timeliness of early warnings. At the same time, differentiated analysis modules have been designed for different types of water conservancy facilities, such as the use of a dynamic reinforcement model for gates and the introduction of a carbonization depth correction for dam bodies, making the solution adaptable to diverse engineering scenarios. Furthermore, a multi-level early warning indicator system, combined with nonlinear behavior analysis, avoids the limitations of fixed thresholds. It can dynamically adjust the warning level based on the actual state of the structure, providing precise guidance for operation and maintenance decisions, significantly reducing the accident rate and operation and maintenance costs.

[0149] Based on the same general inventive concept, the present invention also protects a water conservancy facility safety early warning system. The water conservancy facility safety early warning system provided by the present invention is described below. The water conservancy facility safety early warning system described below and the water conservancy facility safety early warning method described above can be referenced to each other.

[0150] Figure 2 It is a structural diagram of a water conservancy facility safety early warning system provided by an embodiment of the present invention.

[0151] like Figure 2 As shown, a water conservancy facility safety early warning system includes a memory, a processor and a computer program stored in the memory and runnable on the processor. The processor includes a data acquisition module, a water pressure distribution calculation module, a key area screening module, a compressive strength calculation module, a deformation data acquisition module and a comparison early warning module.

[0152] The data acquisition module is used to collect water conservancy project parameters, hydrological data and water conservancy facility structural parameters. The water conservancy facility structural parameters include the label parameters of the concrete dam body and the gate material specifications.

[0153] The water pressure distribution calculation module is used to construct a hydrodynamic mathematical model based on the principles of fluid mechanics according to water conservancy project parameters and hydrological data, and use the finite element method to perform stress analysis on the structure of water conservancy facilities to obtain dynamic water pressure distribution data.

[0154] The key area screening module is used to screen the impact force concentration areas based on the dynamic water pressure distribution data, draw pressure contour maps to locate high-risk areas, and obtain key areas of concern.

[0155] The compressive strength calculation module is used to perform rebound strength testing on key areas of concern, record the concrete surface hardness data and perform conversion to obtain the actual compressive strength value.

[0156] The deformation data acquisition module is used to construct a stamping model based on the gate material specifications, calculate the theoretical deformation curve of the gate, and obtain actual deformation data through laser ranging.

[0157] The comparative warning module is used to compare the actual compressive strength value with the dynamic water pressure distribution data, and analyze the degree of deviation between the actual deformation data and the theoretical deformation curve, establish a multi-level safety warning indicator system, trigger an early warning when the detection value exceeds the safety threshold, and generate an assessment report including the risk location and degree.

[0158] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0159] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A water conservancy facility safety early warning method, characterized in that: include: Collecting water conservancy project parameters, hydrological data and water conservancy facility structural parameters, including the marking parameters of the concrete dam body and the material specifications of the gate; Constructing a hydrodynamic mathematical model based on the principles of fluid mechanics according to the water conservancy project parameters and hydrological data, and using the finite element method to perform stress analysis on the water conservancy facility structure to obtain dynamic water pressure distribution data; Based on the dynamic water pressure distribution data, the impact force concentration area is screened, and a pressure contour map is drawn to locate high-risk areas to obtain key areas of concern; Conduct rebound strength testing on the key areas of concern, record the concrete surface hardness data and convert it to obtain the actual compressive strength value; Constructing a stamping model based on the gate material specifications according to the gate material specifications, calculating the gate theoretical deformation curve, and obtaining actual deformation data through laser ranging; Comparing the actual compressive strength value with the dynamic water pressure distribution data, and analyzing the degree of deviation between the actual deformation data and the theoretical deformation curve, to establish a multi-level safety early warning indicator system; When the detection value exceeds the safety threshold, an early warning is triggered and an assessment report is generated containing the location and extent of the risk.

2. A water conservancy facility safety early warning method according to claim 1, characterized in that: The hydrological data include water level, flow rate, pressure and temperature; the water conservancy project parameters include reservoir capacity and dam geometric dimensions, and the dam geometric dimensions include height, slope and top width.

3. A water conservancy facility safety early warning method according to claim 1, characterized in that: The process of constructing a hydrodynamic mathematical model based on fluid mechanics principles includes: Perform three-dimensional spatial division on the area where the water conservancy facilities are located to form a three-dimensional computational grid, and obtain the boundary range of the water area and water conservancy facilities; Based on the Navier-Stokes equations and the continuity equation, in combination with the water conservancy project parameters and the water conservancy facility structural parameters, initial conditions and boundary conditions are set. The initial conditions represent water flow state parameters, and the boundary conditions are water flow parameter restrictions within the water area and the water conservancy facility boundary range. The water flow state parameters include flow velocity, flow direction, water flow pressure, and water flow density. The water flow parameter restrictions include speed restrictions, pressure restrictions, and flow restrictions at the boundary. The finite volume method is used to discretize the Navier-Stokes equations and the continuity equation, the continuous water flow motion is converted into numerical calculations on discrete nodes, the continuous water flow motion is dynamically simulated, and a hydrodynamic mathematical model is obtained.

4. A water conservancy facility safety early warning method according to claim 1, characterized in that: The process of obtaining dynamic water pressure distribution data includes: Constructing a finite element model of a water conservancy facility structure, wherein the finite element model includes a concrete dam body and a gate; Calculating the water pressure load according to the hydrodynamic mathematical model and applying it to the finite element model in the form of nodal forces; Defining the material constitutive relationship of the finite element model according to the structural parameters of the water conservancy facility, calculating the stress concentration factor of the water conservancy facility structure, and forming a load combination in combination with the water pressure load; In combination with the load combination, the stress field and displacement field of the finite element model in the hydrodynamic mathematical model are solved by a time history analysis method to obtain dynamic water pressure distribution data.

5. A water conservancy facility safety early warning method according to claim 1, characterized in that: The process of screening impact concentration areas includes: The dynamic water pressure gradient of the water flow on the surface of the water conservancy facility structure is calculated based on the dynamic water pressure distribution data, and the surface area of ​​the water conservancy facility structure where the dynamic water pressure gradient exceeds a preset threshold is marked as a potential impact force concentration area.

6. A water conservancy facility safety early warning method according to claim 4, characterized in that: The process of arriving at the focus areas includes: interpolating the dynamic water pressure distribution data onto a regular grid to form a continuous pressure data distribution; Processing the continuous pressure data distribution using a Kriging interpolation algorithm to generate a continuous pressure field; Drawing a closed curve for the continuous pressure field based on equally spaced pressure values ​​to form a pressure contour map; In the pressure contour map, the contour-dense areas and high-value areas are identified, and the key areas of concern are marked in combination with the stress concentration factor.

7. A water conservancy facility safety early warning method according to claim 1, characterized in that: The process of obtaining the actual compressive strength value includes: Select measurement areas within the key focus area, and evenly arrange N measurement points in each measurement area; Use a standard rebound tester to test perpendicular to the concrete surface and record the rebound value at each measuring point; Eliminate abnormal data and calculate the average rebound value of the measurement area, wherein the abnormal data includes abnormal carbonization depth points; Measure the carbonation depth of concrete and determine the thickness of the carbonation layer using the phenolphthalein reagent colorimetric method; The compressive strength of concrete is obtained by comparing and converting the average rebound value of the measured area and the carbonation depth of the concrete with the strength curve.

8. A water conservancy facility safety early warning method according to claim 1, characterized in that: The process of building a stamping model based on the gate material specifications includes: Determine the geometric parameters and load conditions of the gate, wherein the geometric parameters include length, width, thickness and support method, and the load conditions include static water pressure, dynamic water pressure and wave load; Select a material constitutive model that matches the gate material and set the gate material parameters, including elastic modulus, Poisson's ratio, yield strength, and ultimate strength; Define the contact conditions of the gate, including friction contact between the gate and the gate slot; Apply boundary constraints and load distribution to simulate the stress state of the gate under different working conditions and complete the construction of the stamping model based on the gate material specifications.

9. A water conservancy facility safety early warning method according to claim 1, characterized in that: The process of calculating the theoretical deformation curve of the gate includes: Based on the principle of material mechanics and combined with the stamping model, the deflection differential equation of the gate under water pressure is established; Considering the constraints and load distribution of the gate, the double-moment theory is used to solve the deflection differential equation, the constraints include simply supported and fixed supported, and the load distribution includes uniformly distributed load and concentrated load; Based on the solution results, calculate the maximum deflection and stress distribution of the gate under different water levels; Analyze the impact of the gate's nonlinear behavior on deformation, including large deformation effects; Based on the calculation results at different water levels, the theoretical deformation curves of the gate under different working conditions are generated.

10. A water conservancy facility safety early warning system, 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 program, a water conservancy facility safety early warning method according to any one of claims 1 to 9 is implemented.

Images