CN107843713A - Mud-rock flow firing test rainfall simulation method - Google Patents

Abstract

The invention discloses an artificial rainfall simulation method for a debris flow start-up test. The artificial rainfall simulation system for the debris flow start-up test includes an artificial rainfall device, a rainfall monitoring device and a control device. The artificial rainfall device includes a water tank, a water pump, a rainfall bracket and a rainfall nozzle. The rainfall sprinkler head is set on the rainfall support, and the rainfall sprinkler head is connected to the water tank through the water pipeline, and the water tank is connected to the water pump. The rainfall monitoring device records the actual rainfall, soil moisture content, soil displacement and stretching of the tensile sensor, and will detect The received data is sent to the control device, and the control device judges whether a debris flow occurs based on the collected data, and records the slope runoff, slope internal runoff, soil creep deformation and the time when the debris flow occurs during the debris flow. The invention has simple structure and convenient operation, can simulate the occurrence process of mud-rock flow detection under different rainfall types, has fast and accurate detection results, and provides a basis for prediction of mud-rock flow.

Description

Artificial rainfall simulation method for debris flow start-up test

technical field

The invention relates to the technical field of debris flow start-up tests, in particular to an artificial rainfall simulation method for debris flow start-up tests.

Background technique

Debris flow is a solid-liquid two-phase fluid filled with a large amount of sand, stones and boulders. It has the characteristics of sudden outbreak, strong transport impact and silting ability, and great destructive power. The nature of debris flow determines its formation needs Plenty of water. The water source that causes debris flow in my country mainly comes from heavy rain, which shows that when the rainfall reaches a certain critical rainfall value, disasters will form. Therefore, the determination of critical rainfall is of great significance for studying the formation mechanism of debris flow, analyzing and predicting the characteristics of future activities of debris flow, and guiding the design of debris flow prevention and control projects.

Observations and statistical data show that there is a critical rainfall threshold for the occurrence of single-ditch debris flows and regional debris flows, which can be determined based on historical disaster events of debris flows, landforms, geology, topography, soil, vegetation and other influencing factors or experimental methods. In recent years, the research on rainfall conditions of rainfall-type debris flow and disaster prediction based on rainfall factors has attracted the attention of many debris flow scholars at home and abroad, and has become a hot issue in debris flow research in the past ten years. Strong, 1h rain intensity, 24h rainfall, the effective rainfall of the previous n days and other rainfall indicators and the test and statistics of the relationship between debris flow, established a series of forecasting models based on rainfall and rain intensity, which greatly promoted the prediction of debris flow disasters Solve the problem of forecasting and make a contribution to disaster prevention and mitigation in our country.

However, most of the existing debris flow forecasting models are based on statistical data. Debris flows mostly occur in remote mountainous areas where monitoring data is scarce. The universality of many existing models cannot meet the needs of disaster prevention and mitigation. Debris flow start In-situ test or model test, and then determine the rainfall threshold for debris flow initiation in each region according to the underlying surface conditions. Combined with the test phenomenon, it can analyze the characteristics of debris flow initiation, debris flow scale and accumulation characteristics, analyze the disaster-causing ability of debris flow, and evaluate the potential scope of influence. A debris flow start-up model is established to provide a basis for future debris flow forecasting. The existing artificial rainfall device for debris flow start-up has a relatively simple structure and cannot simulate the impact of regional point rainstorms on the start-up of debris flow, and the rainfall conditions cannot be adjusted. The simulated rainfall and actual rainfall conditions are significantly different, resulting in the distortion of the obtained data. The accuracy cannot meet the needs of disaster prevention and mitigation.

Contents of the invention

The purpose of the present invention is to provide an artificial rainfall simulation method for debris flow start-up test, which can simulate different rainfall types and establish debris flow start-up models under different rainfall types to provide a basis for debris flow prediction.

To achieve the above object, the present invention adopts the following technical solutions:

An artificial rainfall simulation system for a debris flow start-up test, comprising an artificial rainfall device, a rainfall monitoring device and a control device. The water pipeline is connected to the water tank, and the water tank is connected to the water pump; the rain gauge is used as the rainfall monitoring device, and the rain gauge is arranged under the rainfall nozzle, and the rain gauge is connected to the control device.

Preferably, the rainfall monitoring device also includes a fixed rod, a measuring rod, a moisture content sensor and a displacement sensor, the fixed rod is inserted into the soil layer outside the rainfall area, the upper part of the fixed rod is provided with a tensile sensor, and the measuring rod is inserted into the rainfall area In the inner soil layer, the top of the measuring rod is connected to the tensile sensor through a steel wire, and the moisture content sensor and the displacement sensor are all buried in the soil layer within the rainfall range, and the output terminals of the tensile sensor, moisture content sensor and displacement sensor are all Connected to the control unit.

Preferably, the rainfall monitoring device further includes a camera, the camera is set outside the rainfall range through the rain bracket, and the camera is connected to the control device.

Preferably, the rainfall support includes a base, a lifting cylinder, a support plate, a first adjustment cylinder and a second adjustment cylinder, the support plate is connected to the base through the lifting cylinder, and the expansion and contraction of the lifting cylinder drives the support plate to rise and fall. The lower end of the first adjustment cylinder is hinged to the support plate, and the other end is connected to the rainfall nozzle. The middle part of the first adjustment cylinder is hinged to one end of the second adjustment cylinder, and the other end of the second adjustment cylinder is hinged to the support plate. Through the first adjustment cylinder and the lifting The expansion and contraction of the oil cylinder can change the height of the rainfall sprinkler head, and the inclination angle between the rainfall sprinkler head and the horizontal plane can be changed through the expansion and contraction of the second adjustment oil cylinder.

Preferably, the water tank includes a main water tank and several sub-water tanks, the main water tank is respectively connected to each sub-water tank through a water delivery pipeline, and there are also multiple rainfall brackets and rainfall nozzles, and each rainfall nozzle is respectively arranged on the rainfall bracket. The water distribution tanks are respectively connected to the rainfall nozzles through water pipelines.

Preferably, pressure regulating valves are provided at the water outlets of the main water tank and each sub-water tank, and pressure gauges and exhaust valves are provided on the main water tank and the sub-water tanks.

Preferably, the control device includes a signal processing unit and a single-chip microcomputer, the input terminals of the signal processing unit are respectively connected with the output terminals of the rain gauge, camera, stretch sensor, moisture content sensor, displacement sensor and pressure gauge, and the output terminals of the signal processing unit The end is connected with the single-chip microcomputer, and the output end of the single-chip microcomputer is respectively connected with the pressure regulating valve, the exhaust valve, the lifting oil cylinder, the first regulating oil cylinder and the second regulating oil cylinder.

Preferably, a remote server is also included, and the remote server communicates with the single-chip computer via wireless.

The method for artificial rainfall simulation using the above-mentioned debris flow start-up test artificial rainfall simulation system includes the following steps in turn:

(1) Select a suitable slope as the test site in the field, use a compass to measure the slope of the slope, and measure the density, early water content and particle composition characteristics of the soil on the slope;

(2) Delineate the test area, arrange rainfall supports, and adjust the direction of rainfall nozzles to ensure uniform rainfall;

(3) Arrange rain gauges, measuring rods, moisture content sensors and displacement sensors in the rainfall area, and arrange fixed poles, stretch sensors and cameras outside the rainfall area;

(4) Turn on the artificial rainfall device, rainfall monitoring device and control device, and start the test;

(5) Record the actual rainfall, soil moisture content, soil displacement and stretching of the stretch sensor respectively, and send the detected data to the control device. The control device combines the collected data with the camera 14 screen, to judge whether a debris flow occurs, and the single-chip microcomputer records the slope runoff, slope internal runoff, soil creep deformation and the time of debris flow during the occurrence of debris flow;

(6) Adjust the opening of the pressure regulating valve, thereby adjusting the amount of rain sprayed by the rainfall nozzle, and simulating different rainfall situations;

(7) Repeat steps (5) and (6), record the occurrence process of debris flow under different rainfall conditions, and establish slope runoff, slope internal runoff, and soil creep deformation during the occurrence of debris flow under different rainfall conditions conditions and the time of formation of mudslides.

The present invention simulates the rainfall situation through the artificial rainfall device, monitors the change of the soil layer under different rainfalls through the rainfall monitoring device, and records the slope runoff, slope internal runoff, soil creep deformation and The time of debris flow formation can establish the start-up model of debris flow under different rainfall types; by adjusting the opening of the pressure regulating valve, the pressure in the water tank can be adjusted, and the corresponding pressure can be set according to the underlying surface conditions and rainfall characteristics of the area, thereby controlling rainfall Type, by adjusting the internal pressure value of the water distribution tank, it is possible to simulate the concentrated phenomenon of regional point rainstorms, by closing one or more of the water distribution tanks, it is possible to simulate the rainfall process in windy weather, and it is also possible to simulate the storm type by overlapping rainfall areas, and the simulation results Fast and accurate; the rainfall monitoring device can collect soil changes in real time, so as to accurately detect the start time and formation process of debris flow, and provide a basis for debris flow prediction and forecasting.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the structural representation of rainfall support of the present invention;

Fig. 3 is a functional block diagram of the present invention;

Fig. 4 is a structural schematic diagram of the pressure regulating valve in the present invention.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments 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 persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Fig. 1 to Fig. 4, a kind of debris flow start-up test artificial rainfall simulation system according to the present invention includes artificial rainfall device, rainfall monitoring device, control device and remote server, and artificial rainfall device is used to realize artificial rainfall, rainfall monitoring The device is used for monitoring the rainfall and the change of the soil layer, the control device is used for controlling the work of the artificial rainfall device and the rainfall monitoring device, and the control device communicates with the remote server via wireless.

The artificial rainfall device comprises a motor 1, a water tank, a water pump 2, a rain support 11 and a rain nozzle 12, and the water tank includes a main water tank 4 and several sub-water tanks 8. In the present embodiment, there are four sub-water tanks 8, and the main water tank 4 passes through the water pump. 2. Connect the motor, the main water tank 4 is also connected to each water distribution tank 8 through the water delivery pipeline 3, and there are four rainfall support 11 and rainfall nozzles 12, each rainfall nozzle 12 is respectively arranged on the rainfall support 11, and each distribution tank 8 is respectively The water delivery pipeline 3 links to each other with the rainfall nozzle 12, and the water delivery pipeline 3 at the water outlet of the main water tank 4 and each water distribution tank 8 is provided with a pressure regulating valve 7, and the main water tank 4 and the water distribution tank 8 are all provided with a pressure gauge 5 and The exhaust valve 6 can adjust the water pressure of the main water tank 4 and each water distribution tank 8 by adjusting the opening of the pressure regulating valve 7, thereby adjusting the rainfall. The pressure gauge 5 is used to detect the water pressure in the main water tank 4 and each water distribution tank 8 Pressure value, the exhaust valve 6 is used to adjust the pressure in the main water tank 4 and the sub-water tank 8, so as to avoid the influence of the test due to excessive pressure fluctuations in the water tank, the pressure gauge is connected with the input end of the control device, and the output ends of the control device are respectively It is connected with the pressure regulating valve 7 and the exhaust valve 6.

The pressure regulating valve 7 includes a valve body 701, a cavity 712 is arranged inside the valve body 701, an installation ring 702 is arranged inside the outlet end of the valve body 701, and an adjustment chamber is arranged on the side wall of the inlet end of the valve body 703, a stud 704 is threadedly connected to the other side wall corresponding to the adjustment chamber 703 at the inlet end of the valve body, and one end of the stud 704 is connected with an adjustment column 706, and the other end is connected with a handle 705, and the outer diameter of the adjustment column 706 is equal to The inner diameter of the adjustment chamber 703, the adjustment column 706 is located in the adjustment chamber 703; the spring 707 is installed on the installation ring 702, the other end of the spring 707 is connected with a conical baffle 709, and the bottom of the conical baffle 709 is fixed with three support rods 708 , the bottom of the support rod 708 is slidingly connected to the side wall of the cavity 712 . A pressure sensor 710 is arranged in the liquid inlet end of the valve body 701 , and the pressure sensor 710 is electrically connected with the display screen 711 . The reading of the pressure sensor 710 displayed on the display screen can be used to adjust the screw-in and screw-out distance of the adjustment column 706 in the adjustment chamber 703 through the handle to adjust the pressure; when the pressure control valve 7 is closed, it is affected by the elastic force of the spring 707 , the conical baffle 709 will block the water inlet end of the cavity 712 to prevent the liquid from flowing back, and the liquid flowing back from the water inlet end of the pressure regulating valve 7 will flush the pressure regulating valve 7 .

The rainfall support includes a base 11-1, a lifting cylinder 11-2, a support plate 11-3, a first adjustment cylinder 11-5 and a second adjustment cylinder 11-4, and the support plate 11-3 passes through the lifting cylinder 11-2 and the base 11 -1 is connected, and the expansion and contraction of the lifting cylinder 11-2 drives the support plate 11-3 to rise and fall. The lower end of the first adjustment cylinder 11-5 is hinged with the support plate 11-3, and the other end is connected to the rainfall nozzle 12. The first adjustment cylinder 11- The middle part of 5 is hinged with one end of the second adjusting oil cylinder 11-4, and the other end of the second adjusting oil cylinder 11-4 is hinged with the support plate 11-3. To change the height of the rain shower head 12, the inclination angle between the rain shower head 12 and the horizontal plane can be changed through the expansion and contraction of the second adjusting oil cylinder 11-4. The lifting oil cylinder 11-2, the first adjusting oil cylinder 11-5 and the second adjusting oil cylinder 11-4 are respectively connected with the control device, and the lifting oil cylinder 11-2, the first adjusting oil cylinder 11-5 and the second adjusting oil cylinder 11-4 are all Existing oil cylinder, its structure and working principle are no longer repeated. In addition, the rain shower head 12 is detachably connected to the first adjustment oil cylinder 11-5, and the rain shower head 12 of different specifications can be replaced during use, thereby simulating different types of rain intensities from light rain to heavy rain.

The rainfall monitoring device includes a rain gauge 10, a fixed rod, a measuring rod, a moisture content sensor, a displacement sensor and a camera 14, the fixed rod is inserted into the soil layer outside the rainfall area, the upper part of the fixed rod is provided with a tensile sensor, and the measuring rod is inserted into the rainfall area In the soil layer, the top of the measuring rod is connected with the tensile sensor through the steel wire, the moisture content sensor and the displacement sensor are all buried in the soil layer within the rainfall range, the camera 14 is arranged outside the rainfall range through the camera bracket 13, and the rain gauge 10 is arranged at Below the rainfall nozzle 12, the output ends of the rain gauge 10, the tension sensor, the moisture content sensor, the displacement sensor and the camera 14 are all connected to the control device.

The control device includes a signal processing unit and a single-chip microcomputer. The input terminals of the signal processing unit are respectively connected with the output terminals of the rain gauge 10, the video camera 14, the tension sensor, the water content sensor, the displacement sensor and the pressure gauge 5, and the output terminals of the signal processing unit are connected with the output terminals of the pressure gauge 5. The single-chip microcomputer is connected, and the output end of the single-chip microcomputer is connected with the pressure regulating valve 7 and the exhaust valve 6 respectively.

In this embodiment, the motor 1 adopts a 3kw gasoline generator, the water pump 2 adopts a 70-meter-lift variable-frequency constant-pressure water pump, the total height of the rainfall support 11 is 3.5 meters, the water delivery pipe 3 adopts a high-pressure rubber water pipe, and the pressure regulating valve 7 adopts a The connection between the solenoid valve, the pressure regulating valve 7 and the water pipeline 3 is treated with sealing tape to prevent water leakage

A method for simulating artificial rainfall by using the artificial rainfall simulation system for the start-up test of debris flow comprises the following steps in sequence:

(1) Select a suitable slope as the test site in the field, use a compass to measure the slope of the slope, and measure the density, early water content and particle composition characteristics of the soil on the slope;

Measuring the soil density, early water content and particle composition characteristics of the slope soil can select the rainfall according to the characteristics of the slope soil, and at the same time facilitate the analysis of the occurrence of debris flows under different soil qualities.

(2) Delineate the test area, arrange the rain support 11, and adjust the direction of the rain nozzle 12 to ensure uniform rainfall;

(3) Arrange rain gauges 10, measuring rods, moisture content sensors and displacement sensors in the rainfall area, and arrange fixed poles, stretch sensors and cameras 14 outside the rainfall area;

(4) Turn on the artificial rainfall device, rainfall monitoring device and control device, and start the test;

(5) Record the actual rainfall, soil moisture content, soil displacement and stretching of the stretch sensor respectively, and send the detected data to the control device. The control device combines the collected data with the camera 14 screen, to judge whether a debris flow occurs, and the single-chip microcomputer records the slope runoff, slope internal runoff, soil creep deformation and the time of debris flow during the occurrence of debris flow;

(6) Adjust the opening of the pressure regulating valve 7, thereby adjusting the amount of rain sprayed by the rainfall nozzle 12, and simulating different rainfall situations;

If there is concentrated rainstorm or long-term strong wind and rainy weather in the area, it can be controlled by adjusting the pressure in the water distribution tank 8, and the rainfall areas of each rainfall nozzle 12 can also be overlapped to simulate the rainfall process under the storm mode.

(7) Repeat steps (5) and (6), record the occurrence process of debris flow under different rainfall conditions, and establish slope runoff, slope internal runoff, and soil creep deformation during the occurrence of debris flow under different rainfall conditions conditions and the time of formation of mudslides.

The invention is simple in structure, easy to operate, can simulate different rainfall types, and can detect slope surface runoff, slope internal runoff, soil creep deformation and formation time of debris flow under different rainfall types. The detection results are fast and accurate, providing a basis for debris flow prediction and forecasting.

Claims (3)

1. A kind of 1. mud-rock flow firing test rainfall simulation method, it is characterised in that manually dropped using mud-rock flow firing test Rain simulation system is simulated, and mud-rock flow firing test rainfall simulation system includes artificial rain device, rainfall monitoring fills Put and control device, the artificial rain device include water tank, water pump, rainfall support and rainfall shower nozzle, rainfall shower nozzle is arranged at On rainfall support, rainfall shower nozzle connects water tank through aqueduct, and water tank is connected with water pump；The rainfall monitoring device uses rainfall Meter, rainfall gauge are arranged at below rainfall shower nozzle, and rainfall gauge is connected with control device；The rainfall monitoring device also include fixed pole, Measurement bar, moisture sensor and displacement transducer, the fixed pole are inserted in the overseas soil layer of rainfall area, and fixed pole top is provided with Stretch sensor, measurement bar are inserted in the soil layer in rainfall region, and the top of measurement bar connects stretch sensor through steel wire, described Moisture sensor and displacement transducer are embedded in the soil layer in the range of rainfall, stretch sensor, moisture sensor and The output end of displacement transducer is connected with control device；The rainfall monitoring device also includes video camera, and video camera is through rainfall Support is arranged at outside rainfall scope, and video camera is connected with control device；The rainfall support include base, hoist cylinder, support plate, First regulation oil cylinder and the second regulation oil cylinder, the support plate is connected through hoist cylinder with base, by the flexible drive of hoist cylinder Support plate is lifted, and the lower end of the first regulation oil cylinder is hinged with support plate, other end connection rainfall shower nozzle, in the first regulation oil cylinder Portion and second regulation oil cylinder one end be hinged, second regulation oil cylinder the other end be hinged with support plate, by first regulation oil cylinder with The flexible height that can change rainfall shower nozzle of hoist cylinder, by the second regulation oil cylinder it is flexible can change rainfall shower nozzle with Angle of inclination between horizontal plane；The water tank includes total water tank and several diversion boxs, total water tank through aqueduct respectively with Each diversion box is connected, and the rainfall support and rainfall shower nozzle also have multiple, and each rainfall shower nozzle is respectively arranged at rainfall support On, each diversion box is connected through aqueduct with rainfall shower nozzle respectively；The water outlet of total water tank and each diversion box is equal Pressure-regulating valve is provided with, pressure gauge and air bleeding valve are provided with total water tank and diversion box；The control device includes Signal processing unit and single-chip microcomputer, the input of signal processing unit respectively with rainfall gauge, video camera, stretch sensor, aqueous The output end of rate sensor, displacement transducer and pressure gauge is connected, and the output end of signal processing unit is connected with single-chip microcomputer, monolithic The output end of machine is connected with pressure-regulating valve, air bleeding valve, hoist cylinder, the first regulation oil cylinder and the second regulation oil cylinder respectively；

   The analogy method comprises the following steps successively：

   （1）Selection in the wild is properly domatic to be used as test site, using the gradient that lining is domatic, and determines the domatic soil body Density, water content early stage and the particle composition characteristic of the soil body；

   （2）Pilot region delimited, arranges rainfall support, and adjusts rainfall shower nozzle direction, ensures that rainfall is uniform；

   （3）Rainfall gauge, measurement bar, moisture sensor and displacement transducer are arranged in rainfall region, in the overseas cloth of rainfall area Put fixed pole, stretch sensor and video camera；

   （4）Artificial rain device, rainfall monitoring device and control device are opened, starts to test；

   （5）The amount of tension of actual rainfall, soil moisture content, the displacement of soil and stretch sensor is recorded respectively, and will inspection The data measured are sent to control device, control device the picture shot with reference to video camera 14, to be judged according to the data collected Whether mud-rock flow occurs, the slope runoff in mud-rock flow generating process is recorded by single-chip microcomputer, runoff, soil body creep become inside slopes Shape situation and the time for forming mud-rock flow；

   （6）The aperture of pressure-regulating valve is adjusted, so as to adjust the rain spray amount of rainfall shower nozzle, simulates different rain falls；

   （7）Repeat step（5）And step（6）, the generating process of mud-rock flow under different rain falls is recorded in, and establish different drops Runoff, soil body creep deformation and formation mud-rock flow inside slope runoff, slopes in the case of rain in mud-rock flow generating process Time.
2. 2. mud-rock flow firing test rainfall simulation method as claimed in claim 1, it is characterised in that：Described pressure is adjusted Section valve includes valve body, and valve body is internally provided with cavity, and the valve body goes out liquid one end and is internally provided with mounting ring, valve body feed liquor one The side wall at end is provided with surge bunker, and stud is threaded with another side wall in valve body feed liquor one end, and one end of stud is connected with tune Segmented column, the other end are connected with handle, and the external diameter of adjustable column is not more than the internal diameter of surge bunker；Spring, spring are installed in mounting ring The other end be connected with conical baffle, the bottom of conical baffle is fixed with three support bars, the bottom of support bar and cavity Side walls connection.
3. 3. mud-rock flow firing test rainfall simulation system as claimed in claim 1, it is characterised in that：Also include long-range clothes It is engaged in device, remote server is through wirelessly and single chip communication.