A method and system for analyzing the destructive effects of rockfall impact on underground pipelines.

Abstract

This invention discloses a method and system for analyzing the destructive effects of rockfall impact on underground pipelines. The method includes determining parameters of the collapsed body, pipeline, and soil; constructing a collapsed body model and an underground pipeline model, placing the underground pipeline model into a trench on a soil simulation component; deploying a data monitoring system inside the underground pipeline model, inside the soil simulation component, and on its surface; using the data monitoring system to collect real-time data on the trajectory of the collapsed body, the instantaneous morphological changes of the collapsed body upon contact with the pipeline, the deformation process of the pipeline surface, and the strain and deformation of the pipeline and soil; and performing real-time data analysis in the control system; obtaining the destructive effects based on the analysis results, thus completing the analysis of the destructive effects of rockfall impact on underground pipelines. This invention helps to comprehensively understand the vulnerability of underground pipelines under rockfall impact, providing a scientific basis for developing targeted protective measures.

Description

Technical Field

[0001] This invention relates to the fields of geological disaster simulation, building demolition blasting and underground pipeline protection technology, specifically to an analysis method and system for the destructive effect of rockfall impact on underground pipelines. Background Technology

[0002] With technological advancements, continuous infrastructure development, and the demolition of old buildings, the safety of underground pipelines is becoming increasingly important. Underground pipelines play a crucial role in transporting energy and water resources. In geologically complex areas such as mountainous regions, landslides and rockfalls occur frequently, posing a serious threat to underground pipelines. The demolition of old and dilapidated buildings in cities also impacts the safety of underground pipelines. Current research methods for studying the destructive effects of landslides and rockfalls on underground pipelines have many limitations, such as the difficulty in accurately simulating actual geological conditions, the movement of falling rocks, and the interaction between pipelines and soil. Therefore, a more comprehensive experimental system and methodology are needed to further investigate this issue. Summary of the Invention

[0003] The purpose of this invention is to provide an analytical method and system for the destructive effect of rockfall impact on underground pipelines. This method can more intuitively reflect the destructive effect of rockfall impact on underground buried pipelines, achieve the principle of controlling a single variable, and solve the stability variation law of buried pipelines at different burial depths and different heights of the rockfall impact, thus providing a basis for the safety and stability evaluation of underground pipelines.

[0004] The present invention adopts the following technical solution:

[0005] A method for analyzing the destructive effects of rockfall impact on underground pipelines includes the following steps:

[0006] S1. Calibrate and debug the data monitoring system, and determine the parameters of the collapsed body, pipeline, and soil.

[0007] S2. Construct the collapse model and the underground pipeline model, and place the underground pipeline model into the trench on the soil simulation component.

[0008] S3. A data monitoring system is deployed inside the underground pipeline model, inside and on the surface of the soil simulation component. The data monitoring system is used to collect images in real time of the movement trajectory of the collapsed body, the instantaneous morphological changes of the collapsed body when it comes into contact with the pipeline, and the deformation process of the pipeline surface. The image data is then analyzed in real time in the control system.

[0009] S4. Use a data monitoring system to obtain the strain and deformation of the pipeline and soil, and perform real-time data analysis in the control system.

[0010] S5. Based on the analysis results, obtain the damage effects and complete the analysis of the damage effects of the collapse and falling body impact on underground pipelines.

[0011] Furthermore, in step S1, the parameters to be determined include the following:

[0012] Based on the first and second similarity theory criteria, parameter design is performed, and the geometric similarity ratio of the model's geometric dimensions and layout geometric dimensions is determined to be L = 1. The cross-sectional dimensions and burial depth are designed based on a 1:1 scale with the prototype dimensions, and the gravitational acceleration similarity ratio C is determined. g =1, density similarity ratio C γ =1, density similarity ratio C r =1, based on the geometric similarity ratio and the unit weight similarity ratio, to achieve full similarity of Poisson's ratio and friction angle, and to design the elastic modulus based on the similarity ratio of the prototype soil elastic modulus of 1.

[0013] The parameters of the collapsed body include shape, mass, angle and release height; the parameters of the pipe include material, diameter, wall thickness and burial depth; and the parameters of the soil include soil type, water content and compaction degree.

[0014] Furthermore, the mass of the collapsed body was 50 kilograms.

[0015] Furthermore, in step S2, the model construction includes the following:

[0016] S201. Stainless steel sheet is pressed into a spherical mold, a steel mesh is set inside the spherical mold, concrete is poured, and strain bricks are fixed on the steel mesh of the spherical mold to obtain a collapse model.

[0017] S202. Based on the geometric similarity ratio L=1, determine the length, outer diameter, inner diameter, and thickness of the buried pipeline. Use four sections of reinforced concrete pipe spliced ​​together with tongue and groove joints to obtain the underground pipeline model.

[0018] S203. Using engineering equipment, dig a trench 3.8m deep, 2m wide and 9m long on the soil simulation component, place the underground pipeline model in the trench, and backfill it using engineering equipment and the soil simulation component.

[0019] S204. The collapsed body model is located 5-10 meters to the side of the buried pipeline. The collapsed body model is hoisted into the underground pipeline model 30 meters directly above it using a robotic arm.

[0020] Furthermore, in step S3, the image data analysis includes the following:

[0021] The data monitoring system includes a high-speed camera, strain gauges, soil pressure gauges, and vibration testing equipment.

[0022] A high-speed camera is positioned on one side of the collapsed body model to record the falling process of the body after it is released from the air and to analyze the falling speed of the collapsed body.

[0023] The strain gauges include circumferential and axial strain gauges. The strain gauges are placed at five monitoring sections inside the underground pipeline model to measure the strain changes at the pipeline measuring points during the impact of the collapsed object.

[0024] The earth pressure gauge is installed inside the soil simulation component to measure the characteristics of earth pressure changes caused by the impact of a collapsed body.

[0025] The vibration tester is placed on the surface of the soil simulation component to monitor the vibration velocity and changes of the ground surface under the impact load of the collapsed body.

[0026] The collapsed body model was hoisted to a height of 30 meters and left stationary. After the data monitoring system was activated, the collapsed body was allowed to fall freely to a fixed point by a release command, and images of the collapsed body's trajectory, the instantaneous morphological changes of the collapsed body upon contact with the pipeline, and the deformation process of the pipeline surface were obtained.

[0027] The trajectory of the collapsed body was extracted using the Qianyanlang software, and the ground contact velocity was calculated. Based on the images of the instantaneous morphological changes of the collapsed body upon contact with the pipeline and the deformation process of the pipeline surface, the compression state of the top, middle, and bottom sections of the same cross-section in the underground pipeline model under impact was obtained.

[0028] Furthermore, earth pressure gauges were installed in the soil 0.5 meters and 1 meter above the ground surface, directly above the central axis of the underground pipeline model; the five monitoring sections included the top, waist, and bottom of two sections one meter below the impact point, and the top of a section three meters to the left and right of the impact point along the axis; the strain gauges were 80 mm long and had a resistance of 120 Ω.

[0029] Furthermore, the vibration testers were placed on the soil surface at distances of 1m, 3m, and 5m from the impact point, directly above the underground pipeline model, along the direction of the pipeline model.

[0030] Furthermore, in step S4, the data analysis includes the following:

[0031] The burial depth of the underground pipeline model was increased by 50cm each time until a depth of 4m was reached. The stress, strain and soil pressure changes of the buried pipeline were recorded when the collapsed body impacted the ground from the same height. Then, keeping the burial depth of the underground pipeline model constant, the collapse heights were taken as 1 / 3h, 1 / 2h, 2 / 3h, h and 2h respectively, and the surface stress of the soil and the maximum stress of the buried pipeline were recorded under different burial depths. Here, h represents the general fall height of the collapsed body.

[0032] If the ultimate stress of the underground pipeline model exceeds the preset safety range or abnormal fluctuations occur, the control system will automatically activate the emergency plan.

[0033] Based on the collected data, it was found that when the pipeline is subjected to a vertical impact from an external force, the strain on the pipeline is mainly circumferential strain, with axial strain as a secondary strain. On the impact axis, the pipeline is first under compression and then transitions to tension. The impact force on the pipeline is distributed in a continuous elliptical shape with the impact axis as the center.

[0034] Furthermore, in step S5, the destructive effects include the following:

[0035] Calculate the impact force p of the collapsed body upon bottoming out based on the principle of energy conservation. max The specific formula is as follows:

[0036]

[0037] Where λ represents the Lamé constant of the soil. E1 represents the elastic modulus of the soil, μ represents the Poisson's ratio of the soil, m represents the mass of the collapsed body, and H represents the fall height of the collapsed body.

[0038] The soil stress σ caused by the impact of the collapsed body on the ground is calculated based on Hertzian contact theory. s The specific formula is as follows:

[0039]

[0040] Where r represents the small radius of the collapsed body,

[0041] This leads to the determination of the surface stress of the soil under impact and the maximum stress σ of the underground pipeline model. max The fitting relationship is as follows:

[0042] σ max =0.42σ s -0.83.

[0043] The pipeline is protected from damage when its allowable ultimate strain exceeds its maximum strain under impact. The specific expression is as follows:

[0044]

[0045] Where, ε top ε represents the ultimate stress that the pipeline is allowed to withstand when subjected to impact, and E represents the elastic modulus of the pipeline.

[0046] Furthermore, this invention also proposes an analysis system for the destructive effects of rockfall impact on underground pipelines, including:

[0047] The preliminary preparation module is used to calibrate and debug the data monitoring system and determine the parameters of the collapsed body, pipeline, and soil.

[0048] The model building module is used to build collapse models and underground pipe models, and to place the underground pipe model into the trench on the soil simulation component.

[0049] The data analysis module is used to deploy data monitoring systems inside the underground pipeline model, inside the soil simulation component, and on its surface. The data monitoring system is used to collect images in real time of the movement trajectory of the collapsed body, the instantaneous morphological changes of the collapsed body when it comes into contact with the pipeline, and the deformation process of the pipeline surface. The image data is then analyzed in real time in the control system. The data monitoring system is also used to obtain the strain and deformation of the pipeline and the soil, and the data is analyzed in real time in the control system.

[0050] The results acquisition module is used to obtain the damage effect based on the analysis results and complete the analysis of the damage effect of the collapse and falling body impact on underground pipelines.

[0051] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects:

[0052] 1. This invention establishes a physical experimental model by determining a reasonable similarity scale, simplifying the analysis of simulated collapse impact tests and achieving adaptability to different engineering realities. By simulating the impact of a collapsing body on a buried pipeline under free fall conditions, and precisely controlling parameters such as the mass, shape, drop height, and speed of the falling rocks, it can simulate various collapse scenarios, making the research results more universal and applicable. It effectively simulates the stress changes of different parts of the buried pipeline during the impact process from external sources, making it closer to engineering reality.

[0053] 2. With the help of a data acquisition device, this invention can obtain detailed data such as pressure, strain and displacement of the pipeline in real time during the impact process. These data provide strong support for in-depth analysis of the failure mechanism, stress distribution and deformation law of underground pipelines, and help to reveal the failure mode and development process of underground pipelines under the impact of landslides and falling rocks.

[0054] 3. This invention can systematically study the effects of different factors on the destructive effects of underground pipelines by changing the burial depth of the pipeline, soil conditions, and the mass, shape, drop height, and speed of falling rocks. This helps to fully understand the vulnerability of underground pipelines under the impact of landslides and falling rocks, and provides a scientific basis for formulating targeted protective measures.

[0055] 4. Based on the results of model tests, this invention can optimize the protective design of underground pipelines, providing an effective means to assess the risks of underground pipelines in specific areas under the threat of landslides and rockfalls. By analyzing local geological conditions and rockfall situations, and combining the results of model tests, the safety status of underground pipelines can be accurately assessed, providing a basis for decision-making in formulating corresponding risk management strategies. Attached Figure Description

[0056] Figure 1 This is an overall structural diagram of the system of the present invention.

[0057] Figure 2 This is a diagram showing the strain gauge bonding positions in the system of this invention.

[0058] Figure 3 This is a diagram showing the layout of the vibration tester in the system of this invention.

[0059] Figure 4 This is a diagram showing the location of the earth pressure gauge measuring points in the system of this invention.

[0060] Figure labels: 1-Collapse model, 2-Underground pipeline model, 3-Strain gauge, 4-Axial strain gauge, 5-Circumferential strain gauge, 6-Vibration tester, 7-Soil pressure gauge. Detailed Implementation

[0061] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0062] To achieve the above objectives, this invention proposes an analytical method for the destructive effect of rockfall impact on underground pipelines, the specific steps of which are as follows:

[0063] S1. Calibrate and debug the data monitoring system, and determine the parameters of the collapsed body, pipeline, and soil; the specific content is as follows:

[0064] Based on the first and second similarity theory criteria, parameter design is performed, and the geometric similarity ratio of the model's geometric dimensions and layout geometric dimensions is determined to be L = 1. The cross-sectional dimensions and burial depth are designed based on a 1:1 scale with the prototype dimensions, and the gravitational acceleration similarity ratio C is determined. g =1, density similarity ratio C γ =1, density similarity ratio C r =1, based on the geometric similarity ratio and the unit weight similarity ratio, to achieve full similarity of Poisson's ratio and friction angle, and to design the elastic modulus based on the similarity ratio of the prototype soil elastic modulus of 1.

[0065] The parameters of the collapsed body include shape, mass, angle and release height; the parameters of the pipe include material, diameter, wall thickness and burial depth; and the parameters of the soil include soil type, water content and compaction degree.

[0066] In this embodiment, the collapsed body is a rockfall with a mass of 50 kilograms.

[0067] S2, such as Figure 1 As shown, a field model experiment was constructed: a collapse model 1 and an underground pipeline model 2 were constructed, and the underground pipeline model 2 was placed into the trench on the soil simulation component; the specific content is as follows:

[0068] S201. Based on the test site and conditions, stainless steel plates are pressed into spherical molds, steel mesh is set inside the spherical molds, and well-mixed concrete is poured. Strain bricks are then fixed on the steel mesh of the spherical molds to obtain the collapse model 1.

[0069] In this embodiment, the inner diameter of the spherical mold is 33cm, the thickness of the steel mesh is 0.8cm, the concrete pouring strength is 30MPa, and the mold is removed after solidification.

[0070] S202. Based on the geometric similarity ratio L=1, determine the length, outer diameter, inner diameter and thickness of the buried pipeline. Use 4 sections of reinforced concrete pipe spliced ​​together with tongue and groove joints to ensure that the pipeline conforms to the general water supply pipeline, and obtain underground pipeline model 2.

[0071] In this embodiment, the steel-reinforced concrete pipe has an inner diameter of 1500mm, an outer diameter of 1800mm, and a length of 2000mm.

[0072] S203. Using engineering equipment, dig a trench 3.8m deep, 2m wide and 9m long on the soil simulation component, and place the underground pipeline model 2 into the trench. Use engineering equipment and the soil simulation component to backfill the trench. When backfilling, ensure that the backfill soil is compacted to ensure that the soil covering the pipeline is in close contact with the pipeline and that the compaction degree is stable.

[0073] S204. The collapsed body model 1 is located 5-10 meters to the side of the buried pipeline. The collapsed body model 1 is hoisted into the underground pipeline model 2 at a position 30 meters directly above it using a robotic arm.

[0074] S3. Based on the on-site engineering geological conditions and experimental plan, a data monitoring system should be deployed inside the underground pipeline model 2, inside the soil simulation component, and on its surface. This system must ensure that during the rockfall impact, it can collect real-time images of the rockfall trajectory, the instantaneous morphological changes upon contact with the pipeline, and the deformation process of the pipeline surface. The image data should be analyzed in real-time within the control system to promptly adjust experimental parameters or detect anomalies and take appropriate measures. Specific details are as follows:

[0075] The data monitoring system includes a high-speed camera, strain gauge 3, vibration tester 6, and earth pressure gauge 7.

[0076] A high-speed camera is set on one side of the collapsed body model 1 to record the falling process of the rocks after they are released from the air and to analyze the falling speed of the rocks.

[0077] like Figure 2 As shown, strain gauge 3 includes an axial strain gauge 4 and a circumferential strain gauge 5. Strain gauge 3 is installed at five monitoring sections inside the underground pipeline model 2 to measure strain changes at the pipeline measuring points during rockfall impact. The five monitoring sections include the top, waist, and bottom sections of two sections one meter below the impact location along the axis, and the top section of a section three meters to the left and right of the impact location along the axis. Strain gauge 3 is 80 mm long and has a resistance of 120 Ω.

[0078] like Figure 3 As shown, the vibration tester 6 is positioned on the soil surface at distances of 1m (test point A), 3m (test point B), and 5m (test point C) from the impact point, along the direction of the pipeline model, directly above the underground pipeline model 2. It is used to monitor the vibration velocity and changes of the ground surface under the impact load of falling rocks. The fixing device of the vibration tester 6 is inserted into the soil to connect the vibration tester 6 with the soil particles, preventing the soft soil characteristics from affecting the vibration propagation and monitoring.

[0079] like Figure 4 As shown, earth pressure gauges 7 are installed in the soil at a distance of 0.5 meters and 1 meter from the ground surface, directly above the central axis of the underground pipeline model 2, to measure the characteristics of earth pressure changes caused by falling rocks.

[0080] The collapsed body model 1 was hoisted to a height of 30 meters and placed still. After the data monitoring system was turned on, the rock was allowed to fall freely to a fixed point by means of a release command. Images of the rock's trajectory, the instantaneous morphological changes when the rock came into contact with the pipe, and the deformation process of the pipe surface were obtained, so as to facilitate subsequent analysis of different working conditions.

[0081] The impact trajectory of the falling rock was observed by setting up a high-speed camera. The rock spent 2.5 seconds in the air. Using the Qianyanlang software to extract the rock's trajectory, its ground impact velocity was calculated to be approximately 24.25 m / s. Images collected by strain gauge 3 on the buried pipeline model showed that the pressure states at the top, middle, and bottom of the same cross-section of the pipeline model differed under impact. Furthermore, the axial strain of the pipeline model was less than the circumferential strain, indicating that under external impact loads, the pipeline model exhibited predominantly circumferential strain, with axial strain playing a secondary role. According to the earth pressure gauge 7 inside the soil model, when the impact point was directly above the buried pipeline, the earth pressure reached 259.2 kPa at 0.5 m above the ground, and 111.9 kPa at 1 m. The earth pressure curve at 0.5 m first reached its peak value, then gradually decreased and stabilized. The earth pressure curve at 1 m showed greater fluctuations over a longer period. Based on the field test plan, a vibration velocimeter was placed on the surface of the soil model. When the rock impacted the ground, the surface vibration reached a peak value, then rapidly decayed, tending towards equilibrium. The vibration velocity decreases continuously with increasing distance from the impact point to the furthest point. The frequencies at each measuring point are mainly concentrated around 25Hz, with the frequency in the z-direction being higher than that in the x and y directions, but the vibration velocity in the z-direction being lower than that in the x and y directions. An impact vibration wave is generated the instant the rock hits the ground surface. Since this wave is located on the soil surface, it has a significant impact on the surface, with the horizontal vibration velocity being higher than the vertical velocity.

[0082] S4. Utilize a data monitoring system to acquire strain and deformation data of the pipeline and soil, and perform real-time data analysis within the control system; specific details are as follows:

[0083] The burial depth of underground pipeline model 2 was increased by 50cm each time until the burial depth reached 4m. The changes in stress and strain on the buried pipeline and soil pressure in the soil were recorded when the collapsed object impacted the ground at the same height. Then, keeping the burial depth of underground pipeline model 2 constant, the collapse heights were taken as 1 / 3h, 1 / 2h, 2 / 3h, 5 / 6h, h, 7 / 6h, and 2h, and the surface stress of the soil and the maximum stress of the buried pipeline were recorded under different burial depths. Here, h represents the general falling height of the rock.

[0084] If the ultimate stress of underground pipeline model 2 exceeds the preset safety range or abnormal fluctuations occur, i.e., the maximum strain of the monitored pipeline exceeds the allowable limit value of reinforced concrete (the ultimate compressive strength in the concrete structure design code is 1.49 MPa), the control system will automatically activate the emergency plan, such as suspending the test and adjusting the rockfall parameters, to ensure the safety of the test and the reliability of the data.

[0085] Based on the collected data, it was found that when the pipeline is subjected to a vertical impact from an external force, the strain on the pipeline is mainly circumferential strain, with axial strain as a secondary strain. On the impact axis, the pipeline is first under compression and then transitions to tension. The impact force on the pipeline is distributed in a continuous elliptical shape with the impact axis as the center.

[0086] In this embodiment, h = 30m.

[0087] S5. Summarize the experimental patterns based on the data analysis results, and evaluate the effectiveness and accuracy of the experimental system and methods. Propose improvement measures and optimization suggestions for the problems found in the experiment, providing a reference for the next experiment or practical engineering application. Simultaneously, compile the experimental data and results into a report to facilitate subsequent research and communication; the specific content includes:

[0088] The impact force p of the falling rock is calculated based on the principle of energy conservation. max The specific formula is as follows:

[0089]

[0090] Where λ represents the Lamé constant of the soil. E1 represents the elastic modulus of the soil, μ represents the Poisson's ratio of the soil; m represents the mass of the falling rock in kg; H represents the height of the falling rock in m.

[0091] The soil stress σ caused by the impact of falling rocks on the ground is calculated based on Hertzian contact theory. s The specific formula is as follows:

[0092]

[0093] Where r represents the minute radius of the falling rock, in meters.

[0094] This leads to the determination of the surface stress of the soil under impact and the maximum stress σ of the underground pipeline model 2. max The fitting relationship is as follows:

[0095] σ max =0.42σ s -0.83.

[0096] The pipeline is protected from damage when its allowable ultimate strain exceeds its maximum strain under impact. The specific expression is as follows:

[0097]

[0098] Where, ε top ε represents the ultimate stress that the pipeline is allowed to withstand when subjected to impact, and E represents the elastic modulus of the pipeline.

[0099] Based on the relationship between different burial depths, the maximum stress of the buried pipeline and the height and mass of the falling rock, it is determined whether the underground pipeline model 2 is damaged when subjected to a specific falling rock impact.

[0100] In this embodiment, the maximum tensile strain experienced by the buried pipeline under different rockfall kinetic energies and pipeline burial depths is shown in Table 1.

[0101] Table 1. Maximum tensile strain experienced by buried pipelines at different burial depths.

[0102]

[0103] The maximum stress of the pipeline and the kinetic energy of the falling rock were fitted under different impact heights and pipeline burial depths, and the fitting relationship under different burial depths is shown in Table 2.

[0104] Table 2 Fitting equations for different burial depths

[0105] Burial depth / m Statistical relationship between maximum stress σ in pipeline and impact energy E from falling rocks <![CDATA[R 2 ]]> 2 <![CDATA[σ=-8.9×10 -4 Yes 2 +0.090E-0.199]]> 0.98 2.5 <![CDATA[σ=6.35×10 -4 AND 2 +0.044E-0.178]]> 0.97 3 <![CDATA[σ=0.002E 2 +0.005E-0.018]]> 0.96 3.5 <![CDATA[σ=0.002E 2 -0.003E+0.016]]> 0.96 4 <![CDATA[σ=0.001E 2 -0.002E+0.012]]> 0.95

[0106] The impact kinetic energy of the falling rock is obtained based on its volume and height. The specific formula is as follows:

[0107] E E =m×g×h

[0108] Among them, E E denoted by , where g represents the impact kinetic energy of the falling rock, and g represents the acceleration due to gravity.

[0109] By fitting the relationship and the maximum allowable stress of concrete, the critical height and critical volume of falling rocks at different burial depths can be obtained.

[0110] This invention also proposes an analysis system for the destructive effects of rockfall impacts on underground pipelines, including a preliminary preparation module, a model building module, a data analysis module, a result acquisition module, and a computer program that can run on a processor. It should be noted that each module in the above system corresponds to a specific step of the method provided in this invention, possessing the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the method provided in this invention.

[0111] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for analyzing the destructive effects of rockfall impact on underground pipelines, characterized in that, include: S1. Calibrate and debug the data monitoring system, and determine the parameters of the collapsed body, pipeline, and soil. S2. Construct a collapse model (1) and an underground pipe model (2), and place the underground pipe model (2) into the trench on the soil simulation component; S3. A data monitoring system is arranged inside the underground pipeline model (2), inside the soil simulation component and on the surface. The data monitoring system is used to collect images of the movement trajectory of the collapsed body, the instantaneous morphological changes of the collapsed body when it comes into contact with the pipeline and the deformation process of the pipeline surface in real time. The image data is analyzed in real time in the control system. The data monitoring system includes a high-speed camera, strain gauge (3), vibration tester (6) and soil pressure gauge (7). S4. Use a data monitoring system to obtain the strain and deformation of the pipeline and soil, and perform real-time analysis of the data in the control system. According to the collected data, when the pipeline is subjected to a vertical impact from an external force, the strain on the pipeline is mainly circumferential strain and supplemented by axial strain. On the impact axis, the pipeline is first under compression and then changes to tension. The impact force on the pipeline is distributed in a continuous elliptical shape with the impact axis as the center. S5. Based on the analysis results, determine the damage effects and complete the analysis of the damage effects of the collapse and falling debris on underground pipelines; specifically: Calculate the impact force p of the collapsed body upon bottoming out based on the principle of energy conservation. max The specific formula is as follows: ； in, The Lamé constant represents the soil. E1 represents the elastic modulus of the soil. represents the Poisson's ratio of the soil; m represents the mass of the collapsed body; H represents the fall height of the collapsed body. The soil stress caused by the impact of the collapsed body on the ground was calculated based on Hertzian contact theory. The specific formula is as follows: ； Where r represents the small radius of the collapsed body, ; This leads to the determination of the surface stress of the soil under impact and the maximum stress of the underground pipeline model (2). The fitting relationship is as follows: = ； The pipeline is protected from damage when its allowable ultimate strain exceeds its maximum strain under impact. The specific expression is as follows: ； ； in, This indicates the ultimate stress that the pipe can withstand under impact. E represents the stress when the pipe is subjected to impact, and E represents the elastic modulus of the pipe.

2. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 1, characterized in that, In step S1, the parameters to be determined include the following: Based on the first and second similarity theory criteria, parameter design is performed, and the geometric similarity ratio of the model's geometric dimensions and layout is determined to be L=1. The cross-sectional dimensions and burial depth are designed based on a 1:1 scale with the prototype dimensions. The gravitational acceleration similarity ratio C... g =1, similarity ratio of bulk density =1, density similarity ratio =1, based on the similarity ratio of geometric similarity ratio and unit weight similarity ratio, to achieve full similarity of Poisson's ratio and friction angle, and to design the elastic modulus based on the similarity ratio of the prototype soil elastic modulus of 1; The parameters of the collapsed body include shape, mass, angle and release height; the parameters of the pipe include material, diameter, wall thickness and burial depth; and the parameters of the soil include soil type, water content and compaction degree.

3. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 2, characterized in that, The mass of the collapsed body is 50 kilograms.

4. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 1, characterized in that, In step S2, the model construction includes the following: S201. Stainless steel sheet is pressed into a spherical mold, a steel mesh is set inside the spherical mold, concrete is poured, and strain bricks are fixed on the steel mesh of the spherical mold to obtain a collapse model (1). S202. Based on the geometric similarity ratio L=1, determine the length, outer diameter, inner diameter and thickness of the buried pipeline. Use 4 sections of reinforced concrete pipe spliced ​​together with tongue and groove joints to obtain the underground pipeline model (2). S203. Using engineering equipment, dig a trench 3.8m deep, 2m wide and 9m long on the soil simulation component, and put the underground pipeline model (2) into the trench, and use engineering equipment to backfill it with the soil simulation component; S204. The collapsed body model (1) is located 5-10 meters to the side of the buried pipeline. The collapsed body model (1) is hoisted into the underground pipeline model (2) 30 meters directly above it by a mechanical arm.

5. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 1, characterized in that, In step S3, the image data analysis includes the following: Among them, a high-speed camera is set on one side of the collapsed body model (1) to record the falling process of the body after it is released from the high altitude and to analyze the falling speed of the collapsed body; The strain gauge (3) includes an axial strain gauge (4) and a circumferential strain gauge (5). The strain gauge (3) is set at five monitoring sections inside the underground pipeline model (2) to measure the strain changes at the pipeline measuring points during the impact of the collapsed body. The earth pressure gauge (7) is installed inside the soil simulation component to measure the earth pressure change characteristics caused by the impact of the collapsed body; The vibration tester (6) is set on the surface of the soil simulation component to monitor the vibration velocity and changes of the ground surface under the impact load of the collapsed body; The collapsed body model (1) was lifted to a height of 30 meters and placed still. After the data monitoring system was turned on, the collapsed body was allowed to fall freely at a fixed point by the unhooking command. Images of the movement trajectory of the collapsed body, the instantaneous morphological changes of the collapsed body when it came into contact with the pipe, and the deformation process of the pipe surface were obtained. The trajectory of the collapsed body was extracted using the Qianyanlang software, and the ground contact velocity was calculated. Based on the instantaneous morphological changes of the collapsed body and the pipeline and the deformation process of the pipeline surface, the pressure state of the top, waist and bottom of the same section in the underground pipeline model (2) under impact was obtained.

6. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 1, characterized in that, Earth pressure gauges (7) are respectively installed in the soil 0.5 meters and 1 meter above the ground surface directly above the central axis of the underground pipeline model (2); the five monitoring sections include the top, waist, and bottom positions of two sections one meter below the impact position, along the axis, and the top position of the section 3 meters to the left and right of the impact position at the center; the strain gauge (3) has a length of 80 mm and a resistance of 120 Ω.

7. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 1, characterized in that, The vibration tester (6) is placed on the soil surface at distances of 1m, 3m and 5m from the impact point, along the direction of the pipeline model, directly above the underground pipeline model (2).

8. The method for analyzing the destructive effect of rockfall impact on underground pipelines according to claim 1, characterized in that, In step S4, the burial depth of the underground pipeline model (2) is increased by 50cm each time until the burial depth is 4m and the burial depth is stopped. The stress and strain of the buried pipeline and the changes in soil pressure in the soil are recorded when the collapsed body impacts the ground at the same height. Then, keeping the burial depth of the underground pipeline model (2) unchanged, the collapse height is taken as 1 / 3h, 1 / 2h, 2 / 3h, h and 2h respectively, and the surface stress of the soil and the maximum stress of the buried pipeline are recorded under different burial depths. Among them, h represents the general falling height of the collapsed body. If the ultimate stress of the underground pipeline model (2) exceeds the preset safety range or abnormal fluctuations occur, the control system will automatically activate the emergency plan.

9. A system applied to the method for analyzing the destructive effect of rockfall impact on underground pipelines as described in claim 1, characterized in that, include: The preliminary preparation module is used to calibrate and debug the data monitoring system and determine the parameters of the collapsed body, pipeline, and soil. The model building module is used to build collapse models and underground pipe models, and to place the underground pipe model into the trench on the soil simulation component; The data analysis module is used to deploy data monitoring systems inside the underground pipeline model, inside the soil simulation component, and on its surface. The data monitoring system is used to collect images in real time of the movement trajectory of the collapsed body, the instantaneous morphological changes of the collapsed body when it comes into contact with the pipeline, and the deformation process of the pipeline surface. The image data is then analyzed in real time in the control system. The data monitoring system is also used to obtain the strain and deformation of the pipeline and the soil, and the data is analyzed in real time in the control system. The results acquisition module is used to obtain the damage effect based on the analysis results and complete the analysis of the damage effect of the collapse and falling body impact on underground pipelines.

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