Debris flow body section impact force experiment and field measurement method

Abstract

The invention discloses a debris flow body section impact force experiment and field measurement method, and the method comprises the steps: building a section empirical Green function through convolution inversion by employing an experiment system and data in section impact force experiment measurement, obtaining a vertical seismic oscillation signal through measurement at any section, and achieving the measurement of solid phase vertical impact force at the position. The flow depth parameter is further introduced, and the measurement of the vertical impact force of the liquid phase on the section is also realized. In the field measurement of the impact force of the section, the problem of field debris flow body simulation identification is solved on the basis of experimental measurement, and the measurement of the vertical impact force of the solid phase and the liquid phase on the section of the channel is realized. The optimization scheme solves the problems of signal compensation and inversion calculation of the particle characteristic particle size by using the power spectral density PSD of the signal. According to the invention, the problem of direct inversion measurement of debris flow impact force by using seismic oscillation signals and the problem of respective measurement of solid-liquid phase vertical impact force are solved, so that seismic monitoring station network data can be more effectively utilized in the field of mountain disasters.

Description

Technical Field

[0001] The present invention relates to the field of debris flow motion characteristic measurement, and in particular to a debris flow cross-section impact force experiment and field measurement method. Background Art

[0002] The scientific description and measurement of debris flow impact characteristics is one of the most important issues in debris flow research and prevention. Debris flow impact force measurement technology is fundamental to debris flow research and prevention. A fundamental question in debris flow impact measurement is the technical means to be used. Currently, the most ideal approach to debris flow impact measurement is to use signals reflecting the debris flow impact motion and then interpret and invert the motion characteristic parameters through signal interpretation. In this approach, the specific choice of signal type is crucial. Seismic signals generated by debris flow impacting the channel bottom contain information about the debris flow's motion process, making them a useful signal type for interpreting debris flow impact characteristics.

[0003] The existing technology, "Research on the Generation Mechanism and Quantitative Analysis of Seismic Signals During Debris Flow Movement" (Zhou Kailai, Southwest Jiaotong University, 2023), uses an indoor water tank model to analyze the time-domain, frequency-domain, and temporal-spectral characteristics of the bottom impact force and seismic signals during debris flow movement, as well as the quantitative relationship between the bottom wave dynamics and seismic signals. However, the sensors are installed at the bottom, making them susceptible to damage in real debris flow environments, limiting their field application. The existing technology, "Research on the Dynamic Mechanism and Early Warning of Outburst Debris Flows Based on Seismic Monitoring: A Case Study of the Bailong River Basin" (Yang Yunpeng, Lanzhou University, 2024), discloses a method for debris flow monitoring, early warning, and quantitative inversion of dynamic parameters based on seismic signals, constructed using indoor and outdoor physical model experiments and long-term field monitoring data. However, the disclosed peak impact force prediction formula is constructed using mass and momentum conservation equations, rather than analytical inversion of seismic signals. While these technologies provide some scientific insights into the relationship between debris flows and seismic signals, they do not offer a practical technical solution for measuring debris flow impact using seismic signal acquisition and analysis.

[0004] The advanced issues of the technical solution of using signal analysis to invert and calculate the impact motion of debris flows also involve: Problem 1. The directly collected motion signal is generated by the debris fluid. In debris flow research, many problems require the analysis framework to be established on the debris fluid section. Therefore, this type of measurement solution also needs to solve the technical problem of effectively separating the "surface signal" from the collected "volume signal" so that the technology can be applied to the characteristics of any section of the debris fluid. Problem 2. In theoretical analysis, debris fluid is generally generalized as a two-phase fluid. How to distinguish and quantify the impact characteristics of the solid and liquid phases of debris flows, especially in the actual needs of prevention and control engineering design, requires that the debris flow impact measurement technology can measure the solid phase impact and liquid phase impact separately. These two problems are also not solved by existing technologies. Summary of the Invention

[0005] In order to overcome the shortcomings and deficiencies of the prior art, the present invention provides a debris flow cross-section impact force test and field measurement method.

[0006] The technical solution adopted by the present invention is a debris flow cross-section impact force experiment and field measurement method, which includes: Build a debris flow flume experimental system, arrange the measuring section M parallel to the flume axis, and intersect the bottom of the flume at the line a ,Wire a Sensors are arranged on the upper portion, and the sensors include normal stress sensors and ground vibration sensors; A debris flow flume simulation experiment was conducted to collect the combined signals of debris flow on section M under different simulation experimental conditions. ], and They are the vertical impact force signal of the debris flow solid phase and the vertical seismic signal of the debris flow solid phase on the same section M; the empirical Green function of the section is constructed by convolution inversion using experimental data , characterizing the cross section M and interpersonal relationships; Arrange an arbitrary monitoring section A1 in parallel with the measurement section M in the debris flow flume, conduct a debris flow flume simulation experiment, and collect the vertical ground motion signal of the debris flow in the flume at section A1. , calculate the vertical impact force of the debris flow solid phase at any monitoring section A1 according to the model of formula (1), (1) Where, To monitor the vertical impact force of the debris flow solid phase at section A1, To monitor the vertical seismic signal at section A1, is the deconvolution part of the empirical Green's function of the cross section, Calculates convolution.

[0007] Furthermore, the method further includes measuring the vertical impact force of the liquid phase on any monitoring section A1; The debris flow flume experimental system, in the cross section M Upper layout flow depth Measuring instruments, online a The pore water pressure sensor is arranged at the upper position; Conduct debris flow flume simulation experiments to collect vertical water pressure of debris flow on section M under different simulation experimental conditions. , using experimental data to construct the expression of formula (2) Model, (2) Where, 、 are the vertical water pressure and debris flow depth on the measuring section M, To simulate the density of debris flow, D is the characteristic parameter of debris flow particle gradation distribution, is the sensing area of ​​the pore water pressure sensor; A debris flow flume simulation experiment was conducted to collect the debris flow depth at the monitoring section A1, and the constructed formula (2) model was used to calculate the vertical impact force of the debris flow liquid phase at section A1. .

[0008] Furthermore, the D yes , the expression function of the model of formula (2) is formula (2.1), (2.1) Where g is the gravitational acceleration constant.

[0009] Furthermore, the empirical Green's function of the cross section is constructed using the experimental measurement method of the debris flow cross section impact force. ; A debris flow seismic signal monitoring system was built at the ditch site, including: setting up a monitoring section A2 perpendicular to the ditch direction, and the section A2 and the ditch bed centerline b Intersection Point O , on the extension line of the ditch bank on one side of section A2 P Arrangement of surface vibration sensors; When the debris flow passes, the collection point P Vertical seismic signals of debris flow , extract the vertical ground motion signal generated at section A2 according to formula (3): , (3) Where, H is the calculation parameter, rfor point O with dot P The straight-line distance between L is the length of the debris flow channel, and n is an empirical value, which is 5, 4, and 3 according to small, medium, and large debris flows respectively.

[0010] Will Substitute the formula 1 model constructed in claim 1 to calculate the vertical impact force of the debris flow solid phase at section A2: .

[0011] Further, at point O The rockfall impact ditch bed surface experiment was arranged at the site, and the ground vibration sensor was used to collect the ground vibration data of the same rockfall impact ditch bed surface experiment conditions. O Place and point P Vertical ground motion signal at 、 ,analyze and , determine the vertical ground motion signal absorption attenuation factor of section A2 Q ; When the debris flow passes, the collection point P Vertical seismic signals of debris flow , using the absorption attenuation factor Q right Perform compensation recovery to obtain vertical earthquake recovery signals of debris flow ; Will = Substitute into formula (3) to calculate .

[0012] Furthermore, according to formula (4) Perform compensation recovery, (4) Where, J 、 K is the calculation parameter, To calculate the intermediate quantity, σ is the stabilizing control factor, e is a natural constant, f for frequency, for The reference angular velocity at 1 Hz, , ω for angular velocity, for The centroid frequency.

[0013] Furthermore, the debris flow seismic signal monitoring system also includes a debris flow depth measuring instrument at section A2, which collects the debris flow depth at section A2. h According to the formula (2), the vertical impact force of the debris flow liquid phase at section A2 is calculated as ,in, Debris flow density ρ 、 Value h 、 D Determined based on on-site observations.

[0014] Furthermore, the vertical impact force of the debris flow liquid phase at section A2 is calculated based on the model of formula (2.1) and formula (5): ,in, Based on on-site observations, = (5) Where, W is the average channel width.

[0015] Furthermore, the Utilizing signals The power spectral density The inversion calculation is determined and implemented according to the following scheme: The debris flow seismic signal monitoring system also includes a debris flow velocity measuring instrument at section A2 to collect the signal at section A2. , debris flow velocity u , flow depth h , calculate the signal The power spectral density , constructed according to formula (6) Inversion calculation model, (6) Where, u is the debris flow velocity at section A2, c is the width of section A2, ξ is the focal depth correction parameter, with a value of 0.4. for The propagation speed of the Rayleigh wave phase at 1 Hz is, f for frequency.

[0016] Furthermore, the model of formula (6) is expressed as formula (6.1), (6.1) Where, e is a natural constant, R and B is the calculation parameter.

[0017] Beneficial effects: The present invention proposes a debris flow cross-section impact force experiment and field measurement method. (1) The present invention specifically provides a technical concept of using seismic signals to reflect debris flow impact movement, and then realizing debris flow impact measurement through signal analysis and inversion. This technical concept establishes a scientific solution between the seismic signals generated by the debris flow movement hitting the ground and the quantification of debris flow impact characteristics, expands the regularity research of the existing technology to a practical and specific technical solution, makes up for the defect that the existing technology is difficult to directly measure the solid-liquid two-phase impact force of the debris flow, and expands the debris flow measurement technology. (2) Since the seismic signal is transmitted by the stratum rock mass, the instrument can only collect the signal generated by the entire debris flow, which limits the utilization of the signal data in the study of debris flow impact problems. The present invention solves the technical problem of extracting and separating the seismic signal generated at the specified section of the debris flow from the debris flow signal through a measurement approach that combines an indoor water tank experiment with a field observation system, that is, effectively separating the "surface signal" from the "body signal". The solution to this problem enables the debris flow research based on the analysis of seismic signals to establish the theoretical analysis framework on the debris flow cross section, which is conducive to the application of the corresponding results in the fluid field to the debris flow research field and technology development. (3) The technical solution of the present invention utilizes the characteristics that the debris flow seismic signal is mainly generated by the impact of particles on the bottom of the channel during the movement of the debris flow. Through the theoretical analysis of the water tank experiment and the application of field measurement technology, the solid phase impact force is calculated using the seismic signal. The liquid phase impact force is calculated by combining the debris flow movement characteristics calculated by the seismic signal, solving the technical problem of separately measuring the impact force generated by the solid phase component and the liquid phase component in the debris flow impact measurement. (4) The technical concept of the present invention introduces the seismic signal analysis method into the study of debris flow problems, solves the most basic solid-liquid two-phase impact force measurement problem, enables the data of the earthquake monitoring network to be more effectively used in the field of mountain disasters, and enhances the social and environmental benefits of the integrated use of public service products. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a flow chart of the method of the present invention; Figure 2 It is a partial schematic diagram of the structure of the debris flow flume experimental system and section M of the present invention; Figure 3 It is a graph of the empirical Green's function G(t) constructed by the present invention; Figure 4 It is a structural diagram of the trench on-site debris flow seismic signal monitoring system of the present invention; Figure 5 is a graph of the vertical earthquake signal U2(t) of the debris flow according to the present invention; Figure 6 The present invention is a graph showing a signal U2′(t) after U2(t) is restored by compensating for the absorption attenuation factor Q; Figure 7 Schematic diagram of vertical earthquake motion signal X2 of debris flow at section A2 extracted by the present invention; Figure 8 The solid phase impact force F at the debris flow section A2 of the present invention is d2 (t) curve graph; Figure 9 is the vertical impact force F of the liquid phase at the debris flow section A2 of the present invention f2 (t) graph.

[0019] The numbers in the accompanying drawings are: 1. Water tank; 2. Sensor; 3. High-speed camera device. DETAILED DESCRIPTION

[0020] It should be noted that, unless there is a conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] like Figure 1 As shown, the debris flow cross-section impact force experiment and field measurement method includes: Build a debris flow flume experimental system, arrange the measuring section M parallel to the flume axis, and intersect the bottom of the flume at the line a ,Wire a Sensors are arranged on the upper portion, and the sensors include normal stress sensors and ground vibration sensors; A debris flow flume simulation experiment was conducted to collect the combined signals of debris flow on section M under different simulation experimental conditions. ], and They are the vertical impact force signal of the debris flow solid phase and the vertical seismic signal of the debris flow solid phase on the same section M; the empirical Green function of the section is constructed by convolution inversion using experimental data , characterizing the cross section M and interpersonal relationships; Arrange an arbitrary monitoring section A1 in parallel with the measurement section M in the debris flow flume, conduct a debris flow flume simulation experiment, and collect the vertical ground motion signal of the debris flow in the flume at section A1. , calculate the vertical impact force of the debris flow solid phase at any monitoring section A1 according to the model of formula (1), (1) Where, To monitor the vertical impact force of the debris flow solid phase at section A1, To monitor the vertical seismic signal at section A1, is the deconvolution part of the empirical Green's function of the cross section, Calculates convolution.

[0022] Preferably, the method further comprises measuring the vertical impact force of the liquid phase on any monitoring section A1; The debris flow flume experimental system, in the cross section M Upper layout flow depth Measuring instruments, online a The pore water pressure sensor is arranged at the upper position; Conduct debris flow flume simulation experiments to collect vertical water pressure of debris flow on section M under different simulation experimental conditions. , using experimental data to construct the expression of formula (2) Model, (2) Where, 、 are the vertical water pressure and debris flow depth on the measuring section M, To simulate the density of debris flow, D is the characteristic parameter of debris flow particle gradation distribution, is the sensing area of ​​the pore water pressure sensor; A debris flow flume simulation experiment was conducted to collect the debris flow depth at the monitoring section A1, and the constructed formula (2) model was used to calculate the vertical impact force of the debris flow liquid phase at section A1. .

[0023] Preferably, the D yes , the expression function of the model of formula (2) is formula (2.1), (2.1) Where g is the gravitational acceleration constant.

[0024] Preferably, the empirical Green's function of the cross section is constructed by using the experimental measurement method of the impact force of the debris flow cross section ; A debris flow seismic signal monitoring system was built at the ditch site, including: setting up a monitoring section A2 perpendicular to the ditch direction, and the section A2 and the ditch bed centerline b Intersection Point O , on the extension line of the ditch bank on one side of section A2 P Arrangement of surface vibration sensors; When the debris flow passes, the collection point P Vertical seismic signals of debris flow , extract the vertical ground motion signal generated at section A2 according to formula (3): , (3) Where,H is the calculation parameter, r for point O with dot P The straight-line distance between L is the length of the debris flow channel; n is an empirical value, which is 5, 4, and 3 according to small, medium, and large debris flows respectively.

[0025] Will Substitute the formula 1 model constructed in claim 1 to calculate the vertical impact force of the debris flow solid phase at section A2: .

[0026] Preferably, at point O The rockfall impact ditch bed surface experiment was arranged at the site, and the ground vibration sensor was used to collect the ground vibration data of the same rockfall impact ditch bed surface experiment conditions. O Place and point P Vertical ground motion signal at 、 ,analyze and , determine the vertical ground motion signal absorption attenuation factor of section A2 Q ; When the debris flow passes, the collection point P Vertical seismic signals of debris flow , using the absorption attenuation factor Q right Perform compensation recovery to obtain vertical earthquake recovery signals of debris flow ; Will = Substitute into formula (3) to calculate .

[0027] Preferably, according to formula (4) Perform compensation recovery, (4) Where, J 、 K is the calculation parameter, To calculate the intermediate quantity, σ is the stabilizing control factor, e is a natural constant, f for frequency, for The reference angular velocity at 1 Hz, , ω for angular velocity, for The centroid frequency.

[0028] Preferably, the debris flow seismic signal monitoring system further includes a debris flow depth measuring instrument at section A2, which collects the debris flow depth at section A2. h According to the formula (2), the vertical impact force of the debris flow liquid phase at section A2 is calculated as ,in, Debris flow density ρ 、 Value h 、 D Determined based on on-site observations.

[0029] Preferably, the vertical impact force of the debris flow liquid phase at section A2 is calculated according to the model of formula (2.1) and formula (5): ,in, Based on on-site observations, = (5) Where, W is the average channel width.

[0030] Preferably, the Utilizing signals The power spectral density The inversion calculation is determined and implemented according to the following scheme: The debris flow seismic signal monitoring system also includes a debris flow velocity measuring instrument at section A2 to collect the signal at section A2. , debris flow velocity u , flow depth h , calculate the signal The power spectral density , constructed according to formula (6) Inversion calculation model, (6) Where, u is the debris flow velocity at section A2, c is the width of section A2, ξ is the focal depth correction parameter, with a value of 0.4. for The propagation speed of the Rayleigh wave phase at 1 Hz is, f for frequency.

[0031] Preferably, the model of formula (6) is expressed as formula (6.1), (6.1) Where, e is a natural constant, R and B is the calculation parameter.

[0032] Example 1 like Figures 2 and 3 As shown, the method of the present invention is used to measure the impact force of the debris flow cross section under experimental environmental conditions.

[0033] 1. Build a debris flow flume experimental system.

[0034] Figure 2 This is a partial schematic diagram of the debris flow flume experimental system structure and section M. Build a debris flow flume experimental system, and arrange the measurement section M parallel to the flume 1 axis. Section M intersects the flume bottom at line a ,Wire a Sensor 2, a flow depth measurement device, and a flow velocity measurement device are arranged on the top. Sensor 2 includes a normal stress sensor, a surface vibration sensor, and a pore water pressure sensor. The normal stress sensor measures the impact force on the trough bed, and the surface vibration sensor measures the seismic signal.

[0035] In this embodiment, the normal stress sensor uses the NOS-F306 uniaxial stress sensor with a frequency of 0.1kHz to 30kHz and a range of 100N. The surface vibration sensor uses the 1A314E acceleration sensor with a frequency of 0.5kHz to 20kHz, a range of 50g, and a sampling frequency of 100Hz. After high-pass filtering, a high-frequency signal above 1Hz is obtained. The ground motion signal frequency is f The frequency range is 1 Hz to 50 Hz, and it can directly collect three types of earthquake signal data: east-west, north-south, and vertical. The collected signal is referenced to the angular velocity at 1 Hz. , signal angular velocity ω =2π, signal centroid frequency =1 Hz, the Rayleigh wave phase propagation speed of the signal at 1 Hz =3.75 km / s. High-speed camera 3 was selected as the flow depth and velocity measurement device, and image analysis was used to measure the depth of debris flow in the flume. , flow rate u The pore water pressure sensor is PX409-100GV with a measuring range of 15 kPa.

[0036] 2. Measurement of solid phase impact force on debris flow section.

[0037] 2.1 Constructing the empirical Green function .

[0038] According to the experimental design, simulated debris flow samples (density , particle gradation distribution characteristic parameters D ), carry out debris flow flume simulation experiments under different simulation experimental conditions, and collect the combined signals of debris flow on section M in each group of experiments [ ]. For any section M under any experimental condition, It is the vertical impact force signal of debris flow solid phase, It is the vertical seismic signal of the solid phase of debris flow.

[0039] In this embodiment, the normal stress data collected by the above sensor is the impact force data of the simulated debris flow. , the impact force signal of debris flow solid needs to be extracted from it Table 1.1 is part of the experimental data collected.

[0040] Table 1.1 Cross-section M data under different experimental conditions of solid phase impact (partial)

[0041] Constructing cross-section empirical Green's function through convolution inversion using experimental data , characterizing the cross section M and relationship between them.

[0042] Figure 3 is the empirical Green's function constructed in this example .

[0043] 2.2 Measure the vertical impact data of the solid phase of the debris flow section.

[0044] Arrange any monitoring section A1 in the water tank (11), and section A1 is parallel to the measurement section M. Use the simulated debris flow sample (similar to the debris flow sample in Section 2.1) and D The debris flow flume simulation experiment was carried out to collect the vertical ground motion signal of the debris flow at section A1 in the flume (11). , calculate the vertical impact force of the debris flow solid phase at any monitoring section A1 according to formula 1 Table 1.2 shows the measurement data and calculation results.

[0045] Table 1.2 Partial measurement data of solid-phase vertical impact at debris flow section A1

[0046] 3. Measurement of vertical impact force of liquid phase in debris flow section.

[0047] 3.1 Construction Computational model.

[0048] According to the experimental design, simulated debris flow samples (density , particle gradation distribution characteristic parameters D ), carry out debris flow flume simulation experiments under different simulation experimental conditions, collect and record experimental parameters in each group of experiments, and the water pressure signal of the debris flow liquid phase on the section M (Measured by pore water pressure sensor). Table 1.3 is part of the experimental data. In this embodiment, the value of D is .

[0049] Table 1.3 Cross-section M data under different experimental conditions of liquid phase impact (partial)

[0050] Using experimental data to construct the expression of formula 2 Model, as shown in Equation 2.1.

[0051] 3.2 Measuring vertical impact data of the liquid phase in debris flow sections Using simulated debris flow samples (same as the debris flow samples in Section 3.1) and D The debris flow flume simulation experiment was carried out to collect the debris flow depth at the monitoring section A1. , using the constructed formula 2-1 model to calculate the vertical impact force of the debris flow liquid phase at section A1 Table 1.4 shows the measurement data and calculation results.

[0052] Table 1.4 Debris flow section A1 liquid vertical impact measurement data (partial)

[0053] Example 2 like Figures 4 to 9 As shown, the method of the present invention is used to measure the impact force of the debris flow cross section under field channel environment conditions.

[0054] 1. Build a channel on-site monitoring system.

[0055] Figure 4 It is a structural diagram of the channel on-site debris flow seismic signal monitoring system.

[0056] A debris flow seismic signal monitoring system was built at the ditch site. L =3900 m, average channel width W = 20 m, set up in the channel perpendicular to the channel direction x Monitoring section A2, width of section A2 c =24 m, section A2 and ditch bed centerline b Intersection Point O The debris flow depth on section A2 is h and flow rate u Measuring device. Extend section A2 to one side of the ditch bank and determine the point on the extension line P point O with dot P Straight-line distance r =15 m. At pointP Arrange surface vibration sensors. The debris flow is a large debris flow, and the density of the channel debris flow is ρ =1600 kg / m 3 The models of the sensors and signal acquisition equipment are the same as those in the first embodiment.

[0057] Determine the characteristic parameters of debris flow particle size distribution by combining field observation and laboratory experiments =0.011 m.

[0058] When the debris flow passes through the point P The vibration sensors at the site collect vertical ground motion signals of debris flow .Signal This is the seismic signal generated by debris flow collected at section A2. The flow depth of section A2 was collected at the same time. h , flow rate u .

[0059] Figure 5 It is the vertical seismic signal of debris flow .

[0060] 2. Compensatory recovery.

[0061] At the point O The rockfall impact test was carried out at the ditch bed surface, and the ground vibration sensor (13) was used to measure the rockfall impact at the ditch bed surface. O Place and point P The vertical seismic signals under the same experimental conditions of rockfall impacting the gully bed surface were collected at 、 .

[0062] analyze and , determine the vertical ground motion signal absorption attenuation factor of section A2 Q =2.8.

[0063] Using the absorption attenuation factor Q right Perform compensation recovery to obtain vertical earthquake recovery signals of debris flow In this embodiment, the formula 4 model is used to perform recovery compensation.

[0064] Figure 6 yes Absorption attenuation factor Q Compensated restored signal .

[0065] 3. Extract the signal .

[0066] Will = Substitute into formula 3 to extract the signal .Signal The signal is generated by debris flow In the figure, the vertical seismic signal generated by section A2.

[0067] Figure 7 The vertical seismic signal of the debris flow at section A2 is extracted .

[0068] 4. Calculation of the solid phase vertical impact force at debris flow section A2.

[0069] Will Substitute the formula 1 model constructed in claim 1 to calculate the vertical impact force of the debris flow solid phase at section A2: .

[0070] Figure 8 is the solid phase impact force at the debris flow section A2 .

[0071] 5. Inversion calculation of characteristic parameters .

[0072] According to the experimental measurement data, it is constructed according to Formula 6 The inversion calculation model specifically adopts the formula 6-1 model.

[0073] Calculating Signals The power spectral density ,according to 、 u =7.0 m / s, c =24m, ξ =0.4, Q =2.8, =3.75 km / s, r= 15m, f =1hz~50hz, calculate the characteristic parameters of debris flow particle gradation distribution according to formula 6-1 model =0.01m.

[0074] 6. Calculation of the vertical impact force of the liquid phase in debris flow section A2.

[0075] The vertical impact force of the debris flow liquid phase at section A2 is calculated based on formula 2-1 and formula 5: .

[0076] Figure 9 is the vertical impact force of the liquid phase at the debris flow section A2 .

[0077] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to mechanical connections or electrical connections; they may refer to direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0078] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various equivalent changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. Experiment and field measurement method of debris flow cross section impact force, characterized by , the method includes: Build a debris flow flume experimental system, arrange the measuring section M parallel to the flume axis, and intersect the bottom of the flume at the line a ,Wire a Sensors are arranged on the upper portion, and the sensors include normal stress sensors and ground vibration sensors; A debris flow flume simulation experiment was conducted to collect the combined signals of debris flow on section M under different simulation experimental conditions. ], and They are the vertical impact force signal of the debris flow solid phase and the vertical seismic signal of the debris flow solid phase on the same section M; the empirical Green function of the section is constructed by convolution inversion using experimental data , characterizing the cross section M and interpersonal relationships; Arrange an arbitrary monitoring section A1 in parallel with the measurement section M in the debris flow flume, conduct a debris flow flume simulation experiment, and collect the vertical ground motion signal of the debris flow in the flume at section A1. , calculate the vertical impact force of the debris flow solid phase at any monitoring section A1 according to the model of formula (1), （1） Where, To monitor the vertical impact force of the debris flow solid phase at section A1, To monitor the vertical seismic signal at section A1, is the deconvolution part of the empirical Green's function of the cross section, Calculates convolution.

2. The debris flow cross-section impact force experiment and field measurement method according to claim 1, characterized in that: The method further includes measuring the vertical impact force of the liquid phase on any monitoring section A1; The debris flow flume experimental system, in the cross section M Upper layout flow depth Measuring instruments, online a The pore water pressure sensor is arranged at the upper position; Conduct debris flow flume simulation experiments to collect vertical water pressure of debris flow on section M under different simulation experimental conditions. , using experimental data to construct the expression of formula (2) Model, （2） Where, 、 are the vertical water pressure and debris flow depth on the measuring section M, To simulate the density of debris flow, D is the characteristic parameter of debris flow particle gradation distribution, is the sensing area of ​​the pore water pressure sensor; A debris flow flume simulation experiment was conducted to collect the debris flow depth at the monitoring section A1, and the constructed formula (2) model was used to calculate the vertical impact force of the debris flow liquid phase at section A1. .

3. The debris flow cross-section impact force experiment and field measurement method according to claim 2, characterized in that: described D yes , the expression function of the model of formula (2) is formula (2.1), （2.1） Where g is the gravitational acceleration constant.

4. The debris flow cross-section impact force experiment and field measurement method according to claim 1, characterized in that: Constructing the empirical Green's function of the cross section using the experimental measurement method of debris flow cross section impact force ; A debris flow seismic signal monitoring system was built at the ditch site, including: setting up a monitoring section A2 perpendicular to the ditch direction, and the section A2 and the ditch bed centerline b Intersection Point O , on the extension line of the ditch bank on one side of section A2 P Arrangement of surface vibration sensors; When the debris flow passes, the collection point P Vertical seismic signals of debris flows , extract the vertical ground motion signal generated at section A2 according to formula (3): , （3） Where, H is the calculation parameter, r for point O with dot P The straight-line distance between L is the length of the debris flow channel; n is an empirical value, which is 5, 4, and 3 according to small, medium, and large debris flows respectively; Will Substitute the formula 1 model constructed in claim 1 to calculate the vertical impact force of the debris flow solid phase at section A2: .

5. The debris flow cross-section impact force experiment and field measurement method according to claim 4, characterized in that: At the point O The rockfall impact ditch bed surface experiment was arranged at the site, and the ground vibration sensor was used to collect the ground vibration data of the same rockfall impact ditch bed surface experiment conditions. O Place and point P Vertical ground motion signal at 、 ,analyze and , determine the vertical ground motion signal absorption attenuation factor of section A2 Q ; When the debris flow passes, the collection point P Vertical seismic signals of debris flows , using the absorption attenuation factor Q right Perform compensation recovery to obtain vertical earthquake recovery signals of debris flow ; Will = Substitute into formula (3) to calculate .

6. The debris flow cross-section impact force experiment and field measurement method according to claim 5, characterized in that: According to formula (4), Perform compensation recovery, （4） Where, J 、 K is the calculation parameter, To calculate the intermediate quantity, σ is the stabilizing control factor, e is a natural constant, f for frequency, for The reference angular velocity at 1 Hz, , ω for angular velocity, for The centroid frequency.

7. The debris flow cross-section impact force experiment and field measurement method according to claim 1, characterized in that: The debris flow seismic signal monitoring system also includes a debris flow depth measuring instrument at section A2, which collects the debris flow depth at section A2. h According to the formula (2), the vertical impact force of the debris flow liquid phase at section A2 is calculated as ,in, Debris flow density ρ 、 Value h 、 D Determined based on on-site observations.

8. The debris flow cross-section impact force experiment and field measurement method according to claim 1, characterized in that: The vertical impact force of the debris flow liquid phase at section A2 is calculated based on formula (2.1) and formula (5): ,in, Based on on-site observations, ＝ （5） Where, W is the average channel width.

9. The debris flow cross-section impact force experiment and field measurement method according to claim 1, characterized in that: described Utilizing signals The power spectral density The inversion calculation is determined and implemented according to the following scheme: The debris flow seismic signal monitoring system also includes a debris flow velocity measuring instrument at section A2 to collect the signal at section A2. , debris flow velocity u , flow depth h , calculate the signal The power spectral density , constructed according to formula (6) Inversion calculation model, （6） Where, u is the debris flow velocity at section A2, c is the width of section A2, ξ is the focal depth correction parameter, with a value of 0.

4. for The propagation speed of the Rayleigh wave phase at 1 Hz is, f for frequency.

10. The debris flow cross-section impact force experiment and field measurement method according to claim 9, characterized in that: The model of formula (6) is expressed as formula (6.1), （6.1） Where, e is a natural constant, R and B is the calculation parameter.

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