Experimental device and experimental method for simulating complete process of superlift burst disaster of tillite lake
1. An experiment device for simulating the whole process of superdeep collapse disaster of a moraine lake caused by ice collapse surge is characterized by comprising a water supply device, a surge triggering device, an energy dissipation device, a buffering device, an experiment water tank main body device, a collecting device, a synchronous measuring system and a monitoring system;
the water supply device comprises a plurality of water pumps with different powers, and is simultaneously connected with a plurality of straight-through water outlet pipes, wherein each pipe orifice of the straight-through water outlet pipes is respectively connected with the water pumps with different powers and used as a water supply orifice of the whole device, the water supply quantity supply with multi-stage and different strengths is realized by switching the water pumps simultaneously or in batches, an electromagnetic flowmeter is arranged at the right end of the water outlet of the straight-through water outlet pipes,
the surge triggering device comprises a T-shaped support with adjustable height, and the bottom end of the T-shaped support is provided with a convex prismatic table for supporting the lower edge of the ice cube simulation body; the cathode of the electromagnet is embedded in the upper edge of the ice block supporting simulation body, and the cathode and the anode electromagnet arranged on the T-shaped bracket can be closely adsorbed, so that the fixing function of the ice block before the ice block collapse simulation is realized;
the buffering device is arranged right below the T-shaped bracket;
one side of the T-shaped bracket is provided with an energy dissipation device;
the experimental water tank main body device is matched with the synchronous measuring system and the monitoring system for use, the experimental water tank main body is divided into three sections which are respectively a surge excitation propagation section, a moraine dam body erosion simulation section and a debris flow movement monitoring section, the three sections of water tanks are connected through bolts, the joints are buffered by rubber pads and coated with glass cement for waterproof treatment, and the three sections of water tanks are adjusted to be positioned on the same horizontal plane and are placed on a steel pipe support which is adjusted to be horizontal in advance;
an ultrasonic distance sensor is arranged above the water tank at the surge excitation and propagation section at a certain distance from the origin, at least one hole pressure sensor is arranged at a position close to a dam foot, and a camera is arranged for monitoring the waveform of the surge in the water tank at the section;
reserving vacant sites on the inner side water tank wall and the bottom of the water tank of the erosion simulation section of the ice and moraine dam body respectively, penetrating through the micro pore water pressure sensor, and pre-burying and placing the vacant sites in the dam body of the erosion simulation section of the ice and moraine dam body; the method comprises the steps that a digital camera is respectively arranged on axial lines of an upstream slope surface and a downstream slope surface of a corrosion simulation section of a rock icing dam body for monitoring slope surface corrosion, a high-speed camera is used for realizing high-frequency automatic photographing, a deformation field before and after collapse is calculated by means of a particle image speed measurement method, a laser displacement sensor, an ultrasonic sensor and a digital camera are arranged above a hole pressure sensor at a downstream dam toe for measuring the flow depth and the flow speed at the dam toe of the corrosion simulation section of the rock icing dam body and for converting the collapse flow at the dam toe of the corrosion simulation section of the rock icing dam body;
the debris flow motion monitoring section is provided with a module preformed groove for mounting the force plate module and the ground sound measuring module, and the module preformed groove is internally provided with a protruding step so that the force plate module and the ground sound measuring module can freely move in the transverse direction in the water tank; the top of the module reservation groove is provided with a sensor group and a camera for recording the flow depth, the flow speed and the motion state of the fluid at the position of the module, and all the acquired data are synchronously transmitted to the synchronous measurement system of the water groove and recorded in the memory;
the experiment water tank main body device is used for providing illumination for the experiment water tank main body device;
the collecting device comprises a filtering device and a wastewater collecting box, and wastewater enters the wastewater collecting box after passing through the filtering device to wait for centralized treatment.
2. The apparatus of claim 1, wherein the electromagnetic flow meter is powered with 220V independent ac power and is configured with an independent liquid crystal display to display in real time the volumetric flow rate of fluid through the conduit.
3. The device according to claim 1, wherein two cameras are provided for monitoring the wave shape of the water channel surge, and the two cameras are arranged at intervals and staggered to eliminate measurement errors caused by the wide angle effect of the cameras.
4. The apparatus of claim 1, wherein the surge excitation and propagation section is an arcuate flume.
5. The device of claim 1, wherein the ultrasonic distance sensor is fixed by a tripod at two ends and a freely rotatable cross bar, and the sound wave generating surface is adjusted to be vertical to the bottom surface of the water tank and then the sensor is fixed by screwing screws in circular holes of the tripod.
6. The apparatus of claim 1, wherein the filtering means comprises a collection box with a pre-cut square hole on the side, and a metal screen is installed in the hole to filter the solid particulate matter in the experimental wastewater for waste collection.
7. An experiment method for simulating the whole process of superdeep collapse disaster of a moraine lake caused by ice collapse surge is characterized by comprising the following steps of:
step 1: calibrating a sensor: before the experiment, each sensor should be statically calibrated and dynamically calibrated;
step 2: arranging an experimental device: assembling each device according to the device structure of any one of claims 1 to 6;
and step 3: preparation of the experiment:
1) stacking the dam body on the geometric shape with a pre-drawn outline by adopting a layered accumulation method, wherein the shape outline is calculated and drawn on the glass on one side of the water tank in advance; when the dam is piled up, the layers are tapped to a designated horizontal line by hands, and the compactness of the piled dam can be ensured by controlling the mass of the soil body between each layer; the compactness of the whole model dam body can be relatively uniform by repeating the operation;
2) pre-placement of ice cubes of different volumes: the length, width and height of the ice cake are made of polypropylene plastic plates with the same density as the ice cake: the device comprises a cuboid with the size of 0.5m multiplied by 0.42m multiplied by 0.18m, wherein an electromagnet is embedded in the top of the cuboid, the cuboid can be tightly adsorbed on a T-shaped support, the PP plate plastic is placed on the T-shaped support and electrified by the electromagnet before an experiment begins, and the placing work of ice blocks is completed;
3) opening all sensors, testing the response conditions of all the sensors, blocking signal sources of the ultrasonic and laser sensors by using an opaque square paper board in sequence, and observing whether the signal intensity on the synchronous acquisition system changes, wherein the change is the response; slightly pressing the probe of the micro pore pressure sensor by a hand to observe whether the signal intensity on the synchronous acquisition system changes, wherein the change is a response; the force plate module connected with the pressure plate is slightly pushed and pressed by hand to respectively test the response of the shear stress and the normal stress, and meanwhile, whether the signal intensity on the synchronous acquisition system changes or not is observed, and the change is the response; the bottom pore pressure sensor needs to be filled with water by a needle tube and then is subjected to a slight pressing test to avoid the influence of air on a pore pressure signal and observe whether the signal intensity on the synchronous acquisition system changes or not, and if the change is changed, the response is provided;
and 4, step 4: the experiment was started: when the experiment starts, the synchronous measurement system is opened in advance and collects a section of data to calibrate an initial value; then, a water supply system is opened, the current flow can be displayed timely through the reading on a display screen of the electromagnetic flowmeter, and the flow can be finely adjusted to the specified flow of the experiment through a flow flange on the right; when the water level in the water tank reaches 3/4 with a specified volume, closing the water supply system and throwing a large number of foam balls on the water surface to be used as tracer particles for capturing the change condition of the water surface waveform; after the lake surface is full of tracer particles, the water supply system is opened again, the water level is added to a specified position by the same operation and then water supply is stopped, then, an electromagnet switch is triggered to release ice blocks, the ice blocks are rotated, collapsed and fall into the water and are stimulated to surge, the experiment formally starts, and data monitored by the synchronous measurement system and the monitoring system are recorded;
and 5: and (6) experimental cleaning.
8. The method according to claim 7, wherein in the step 1, in the static calibration, the ultrasonic distance measuring sensor, the pore water pressure sensor and the force plate are calibrated;
calibrating the pore water pressure sensor by using the pressure generated by the static water heads with different heights, and finding out the corresponding relation between the pore water pressure and the voltage signal; meanwhile, the positive stress in the force plate sensor can be calibrated by water heads with different heights, and the mutual verification is carried out between the positive stress and the pore pressure sensor; calibrating the normal stress and the shear stress of the force plate by using the pressure generated by weights with different weights, and finding out the corresponding relation between the normal stress and the shear stress of the debris flow on the force plate and the voltage signal respectively;
calibrating the sensor by using different distances between the ultrasonic ranging sensor and the barrier, and finding out the corresponding linear relation between the ultrasonic ranging sensor and the voltage signal;
the micro pore pressure sensor needs a vacuum pump to evacuate air in the permeable stone, and then the porous stone is soaked into water quickly, so that water is sucked back to saturate the permeable stone, the purpose of removing air in the permeable stone is achieved, and the pore pressure sensor calibration of a normal flow can be started after the operation is repeated for tens of times.
9. The method according to claim 8, wherein in step 1, after the static calibration is completed, all sensors are installed at the designated positions of the water tank, including the earth-sound sensors which are not calibrated, and dynamic calibration is performed.
10. The method as claimed in claim 8, wherein in step 5, after the experiment is completed, the dam material accumulated in the water tank is cleaned by a shovel, and the silt deposited in the pore water pressure at the bottom of the water tank is cleaned at the same time, so as to prevent the influence on the next experiment, and the dam material in the waste collection tank at the tail end of the water tank can be prepared for the next experiment after being emptied.
Background
Glaciers are indicators of climate change and also important solid reservoirs of fresh water resources, and modern glaciers are distributed in almost all latitudes around the world. Glaciers on earth, about 2900 tens of thousands square kilometers, cover 11% of the area of the continents. The iced lake is a glacier lake for short, is formed by glacier action, and is one of the common disaster types in mountain areas, and the burst flood is characterized by outburst, wide influence range and serious damage, and has wide attention due to serious threat to the life safety of local residents and damage to infrastructure. When the ice lake breaks down flood to cause debris flow disasters, the foundation facilities such as roads, railways and the like can be flushed, rivers are blocked to form a dammed lake, and further secondary disasters are caused, even the whole village is buried, and the like, so that the safety of lives and properties of people is seriously threatened.
Due to the low frequency and wide distribution range of natural ice lake burst flood (GLOFs) events and the characteristic that the natural ice lake burst flood (GLOFs) events mostly occur in high mountain altitude areas, people are difficult to carry out effective field monitoring on the GLOFs and acquire real burst data. Therefore, the research work on the mechanism of the iced lake burst is lacked. Compared with field monitoring, the indoor water tank experiment is a method which has controllable experimental conditions and can systematically research the ice lake burst, and is the most common method which has the strongest feasibility and is used for researching the ice lake burst mechanism and the overall process disaster chain thereof at present. A conventional experimental water tank is usually limited to artificially simulate the debris flow and monitor the formation and movement processes of the debris flow, so that basic data in the formation, movement and development processes of the debris flow are measured, and basic research on the movement mechanism of the debris flow is realized. For example, Qinhongwu et al (patent application No. 201610177817.5) disclose a simulation test system that integrates the start, transportation and accumulation of debris flow; zhang et al (patent application No. 201510768066.X) discloses a simulation experiment system for debris flow movement and accumulation, which can be used for carrying out experiments on the influence of various factors (such as gradient, slurry viscosity and friction) on the debris flow movement and accumulation process; wu hong gang et al (patent application number: 201710235878.7) disclose a debris flow simulation test device and a test method, which mainly solve the problem of the non-continuity of the debris flow of the existing debris flow simulation device; ceramic Shi gang et al (patent application No. 201510768066.X) disclose a debris flow physical model experiment system and a debris flow simulation assembly thereof, which can perform physical simulation of the whole process of debris flow with various slope angles and scouring sectors; von wenka et al (patent application No. 201710161230.2) disclose a debris flow simulation test apparatus and a test method thereof, which are capable of dynamically simulating landslide sources, slope sources, and the like on both sides of a debris flow channel. These debris flow simulation devices are rational and versatile in function.
However, it cannot extract the key mechanical parameters of the disaster-causing phenomenon in the whole disaster process. Therefore, the dynamic relation among all disaster-causing phenomena in the whole ice lake burst process cannot be deeply analyzed, and the cognition of the highly destructive ice lake burst natural disaster is limited. In addition, the experimental water tank devices cannot realize disaster simulation in the whole process of 'ice collapse-surging-overtopping-debris flow', and cannot monitor key dynamics and environmental noise acoustic parameters. Such as lack of monitoring of vibration signals during ice collapse; monitoring of a seepage field and a deformation field in the collapse process of the ice and moraine dam body is lacked; the measuring module and the synchronous data acquisition system for the normal stress of the substrate, the shear stress of the substrate and the pore water pressure in the debris flow movement process are lacked, so that the stress state of the debris flow substrate, particularly the effective stress in the debris flow movement process, cannot be effectively obtained. Due to the lack of basic data in the disaster causing process, the vibration signals of the whole process of 'ice collapse, surge, overtopping and debris flow' cannot be combined and analyzed with the traditional kinetic parameters, so that the understanding and comprehension of the kinetic mechanism of the whole process of the icelake burst disaster cannot be further improved.
Disclosure of Invention
In view of the above, the invention aims to provide an experimental device and an experimental method for simulating the whole process of superlift collapse disaster of a moraine lake, and mainly solves the problems that in the current research on the collapse kinetic mechanism of the moraine lake, the synchronous monitoring on important kinetic parameters and environmental noise vibration signals in a debris flow formed by collapse flood of the moraine lake is lacked, and the measurement and calculation on an internal seepage field and an external deformation field in the collapse process of a dam body of a model dam are lacked; still solved traditional indoor model basin and because of paying close attention to a certain calamity process and lead to the drawback that the whole calamity chain can't be reflected to the experimental parameter that monitors. The experimental device for simulating the overall process of the superfall collapse disaster of the moraine lake due to the icebreaking swell realizes the measurement of the overall process and the overall service life of the traditional dynamic parameters, such as the synchronous measurement of the flow velocity, the flow depth, the pore water pressure, the normal stress, the shearing stress and the effective stress in the movement process of forming the debris flow by the collapse flood; meanwhile, the newly designed detachable and movable earth sound acquisition module and the force plate module can effectively capture environmental noise vibration signals in the movement process of the debris flow; meanwhile, the stress acquisition module on the force plate can acquire the shear stress, the normal stress and the pore water pressure in the debris flow movement process in real time. Therefore, the module can realize the synchronous measurement of the environmental noise vibration signal and the traditional dynamics parameters, realizes the organic combination between two subjects of modern environmental noise acoustics and traditional debris flow dynamics, leads the traditional disaster field to the field of the modern environmental noise acoustics, and widens the research visual field. Through the comparison and combination analysis of the two signals, the advanced early warning of the ice lake burst disaster can be expected to be realized, the understanding of a dynamic mechanism in the process of the movement of the burst flood debris flow can be deepened, and the understanding of the whole ice lake burst disaster process and the whole life disaster chain can be deepened. In addition, a seepage field in the interior of the dam body before bursting can be calculated by using a micro pore pressure sensor pre-embedded in the interior of the moraine dam; the high-speed camera captures the shot high-definition time sequence images, so that the deformation field of the tillite dam body can be effectively obtained, and the collapse mechanism of the tillite dam body can be quantitatively researched.
In order to achieve the purpose, the technical scheme of the invention is as follows:
an experiment device for simulating the whole process of superdeep collapse disaster of a moraine lake caused by ice collapse surge comprises a water supply device, a surge triggering device, an energy dissipation device, a buffering device, an experiment water tank main body device, a collecting device, a synchronous measuring system and a monitoring system;
the water supply device comprises a plurality of water suction pumps with different powers, and is simultaneously connected with a plurality of straight-through water outlet pipes, wherein each pipe orifice of the straight-through water outlet pipes is respectively connected with the water suction pumps with different powers and used as a water supply orifice of the whole device, the water supply quantity supply with multi-stage and different strengths is realized by switching the water suction pumps simultaneously or in batches, an electromagnetic flowmeter is arranged at the right end of the water outlet of the straight-through water outlet pipes,
the surge triggering device comprises a T-shaped support with adjustable height, and the bottom end of the T-shaped support is provided with a convex prismatic table for supporting the lower edge of the ice cube simulation body; the cathode of the electromagnet is embedded in the upper edge of the ice block supporting simulation body, and the cathode and the anode electromagnet arranged on the T-shaped bracket can be closely adsorbed, so that the fixing function of the ice block before the ice block collapse simulation is realized;
the buffering device is arranged right below the T-shaped bracket;
one side of the T-shaped bracket is provided with an energy dissipation device;
the experimental water tank main body device is matched with the synchronous measuring system and the monitoring system for use, the experimental water tank main body is divided into three sections which are respectively a surge excitation propagation section, a moraine dam body erosion simulation section and a debris flow movement monitoring section, the three sections of water tanks are connected through bolts, the joints are buffered by rubber pads and coated with glass cement for waterproof treatment, and the three sections of water tanks are adjusted to be positioned on the same horizontal plane and are placed on a steel pipe support which is adjusted to be horizontal in advance;
an ultrasonic distance sensor is arranged above the water tank at the surge excitation and propagation section at a certain distance from the original point, at least one hole pressure sensor is arranged at a position close to a dam foot, and a camera is arranged for monitoring the waveform of the surge in the water tank at the section;
reserving vacant sites are respectively arranged on the inner side water tank wall and the bottom of the water tank of the erosion simulation section of the ice and moraine dam body, penetrate through the micro pore water pressure sensor and are pre-buried in the inner side of the dam body of the erosion simulation section of the ice and moraine dam body; the method comprises the steps that a digital video camera is respectively arranged on axial lines in an upstream slope and a downstream slope of an erosion simulation section of a rock ice dam body for monitoring slope erosion, a high-speed video camera is used for realizing high-frequency automatic photographing, deformation fields before and after collapse are calculated by means of a particle image speed measurement method, a laser displacement sensor, an ultrasonic sensor and a digital camera are arranged above a hole pressure sensor at the downstream dam toe for measuring the depth and the flow speed of the dam toe of the erosion simulation section of the rock ice dam body and for converting the collapse flow at the dam toe of the erosion simulation section of the rock ice dam body;
the debris flow motion monitoring section is provided with a module preformed groove for mounting the force plate module and the earth-sound measuring module, and the module preformed groove is internally provided with a protruding step so that the force plate module and the earth-sound measuring module can freely move in the transverse direction in the water tank; the top of the module reservation groove is provided with a sensor group and a camera for recording the flow depth, the flow speed and the motion state of fluid at the position of the module, and all acquired data are synchronously transmitted to a synchronous measurement system of the water groove and recorded in a memory;
the experiment water tank main body device is used for providing illumination for the experiment water tank main body device;
the collecting device comprises a filtering device and a wastewater collecting box, and wastewater enters the wastewater collecting box after passing through the filtering device to wait for centralized treatment.
Preferably, the electromagnetic flowmeter is powered by 220V independent alternating current and is provided with an independent liquid crystal display screen to display the volume flow of the fluid in the pipeline in real time.
Preferably, two cameras are arranged for monitoring the wave shape of the surge wave in the water tank, and the two cameras are arranged in a staggered mode so as to eliminate measurement errors caused by the wide-angle effect of the cameras.
Preferably, the surge excitation and propagation section is an arc-shaped water tank.
Preferably, the ultrasonic distance sensor is fixed by matching a tripod at two ends with a cross rod which can be rotated, and the sound wave generating surface is adjusted to be vertical to the bottom surface of the water tank and then the sensor is fixed by screwing screws in circular holes of the tripod.
Preferably, the filtering device comprises a collecting box, a side surface of the collecting box is pre-dug to form a square hole, and a metal sieve is arranged in the hole and used for filtering solid particulate matters in the experimental wastewater to collect waste materials.
An experiment method for simulating the whole process of superfall collapse disaster of a moraine lake caused by ice collapse surge comprises the following steps:
step 1: calibrating a sensor: before the experiment, each sensor should be statically calibrated and dynamically calibrated;
step 2: arranging an experimental device: assembling each device according to the device structure of any one of claims 1 to 6;
and step 3: preparation of the experiment:
1) stacking the dam body on the geometric shape with a pre-drawn outline by adopting a layered stacking method for the experimental soil, and drawing the shape outline on the glass on one side of the water tank in advance through calculation; when the dam is piled up, the layers are tapped to a designated horizontal line by hands, and the compactness of the piled dam can be ensured by controlling the soil mass between each layer; the compactness of the whole model dam body can be relatively uniform by repeating the operation;
2) pre-placement of ice cubes of different volumes: the length, width and height of the ice cake are made of polypropylene plastic plates with the same density as the ice cake: the device comprises a cuboid with the size of 0.5m multiplied by 0.42m multiplied by 0.18m, wherein an electromagnet is embedded in the top of the cuboid and can be tightly adsorbed on a T-shaped support, the PP plate plastic is placed on the T-shaped support and electrified by the electromagnet before an experiment begins, and the placing work of ice blocks is finished;
3) opening all sensors, testing the response conditions of all the sensors, blocking signal sources of the ultrasonic and laser sensors by using an opaque square paper board in sequence, and observing whether the signal intensity on the synchronous acquisition system changes, wherein the change is the response; slightly pressing the probe of the micro pore pressure sensor by hand to observe whether the signal intensity on the synchronous acquisition system changes, wherein if the signal intensity changes, a response is obtained; the force plate module connected with the pressure plate is slightly pushed and pressed by hand to respectively test the response of the shear stress and the normal stress, and simultaneously, whether the signal intensity on the synchronous acquisition system changes or not is observed, and the change is the response; the bottom pore pressure sensor needs to be filled with water by a needle tube and then lightly pressed for testing so as to avoid the influence of air on pore pressure signals, and whether the signal intensity on the synchronous acquisition system changes or not is observed, and the change is responded;
and 4, step 4: the experiment was started: when the experiment starts, the synchronous measurement system is opened in advance and collects a section of data to calibrate an initial value; then, a water supply system is opened, the current flow can be displayed timely through the reading on a display screen of the electromagnetic flowmeter, and the flow can be finely adjusted to the specified flow of the experiment through a flow flange on the right; when the water level in the water tank reaches 3/4 with a specified volume, closing the water supply system and throwing a large number of foam balls on the water surface to be used as tracer particles for capturing the change condition of the water surface waveform; after the lake surface is fully paved with the tracer particles, the water supply system is turned on again, the water level is added to the designated position by the same operation, the water supply is stopped, then, the electromagnet switch is triggered to release the ice blocks, the ice blocks are rotated, collapsed and fall into the water and stimulate the surge, the experiment formally starts, and the data monitored by the synchronous measurement system and the monitoring system are recorded;
and 5: and (6) experimental cleaning.
Preferably, in the step 1, in the static calibration, the ultrasonic ranging sensor, the pore water pressure sensor and the force plate are calibrated firstly;
calibrating the pore water pressure sensor by using the pressure generated by the static water heads with different heights, and finding out the corresponding relation between the pore water pressure and the voltage signal; meanwhile, the water heads with different heights can calibrate the normal stress in the force plate sensor, and mutual verification is carried out between the normal stress and the pore pressure sensor; calibrating the normal stress and the shear stress of the force plate by using the pressure generated by weights with different weights, and finding out the corresponding relations between the normal stress and the shear stress of the debris flow on the force plate and the voltage signal respectively;
calibrating the sensor by using different distances between the ultrasonic ranging sensor and the obstacle, and finding out the corresponding linear relation between the ultrasonic ranging sensor and the voltage signal;
the micro pore pressure sensor needs a vacuum pump to evacuate air in the permeable stone, and then the porous stone is soaked into water quickly, so that water is sucked back to saturate the permeable stone, the purpose of removing air in the permeable stone is achieved, and the pore pressure sensor calibration of a normal flow can be started after the operation is repeated for dozens of times.
Preferably, in step 1, after the static calibration is completed, all sensors are installed at the designated positions of the water tank, including the geomagnetic sensors which are not calibrated yet, and dynamic calibration is performed.
Preferably, in step 5, after the experiment is completed, the dam material accumulated inside the water tank is cleaned by a shovel, and simultaneously the silt deposited inside the pore water pressure at the bottom of the water tank is cleaned, so that the influence on the next experiment is prevented, and the dam material in the waste collection tank at the tail end of the water tank can be prepared for the next experiment after being emptied.
Compared with the prior art, the invention has the following advantages:
the experimental device for simulating the ice lake overtopping burst caused by natural ice collapse surge and the experimental method thereof have reasonable conception, consider the indoor simulation of the whole process of the ice collapse surge burst disaster causing, newly add various types of measuring sensors, design and install a set of real-time dynamic measurement monitoring system, can measure most of dynamics, environmental noise acoustics and imaging parameters in the disaster evolution process, are favorable for analyzing the mechanical mechanism in the disaster forming process in a multi-angle and multi-dimension mode, and deepen the understanding of the disaster causing. The method mainly solves the problems that at present, the monitoring and analysis of vibration signals in an icecave overtopping collapse disaster chain is deficient, the collapse mechanism of the icecave dam is not thoroughly understood, and key dynamics parameters, imaging parameters and environmental noise acoustic parameters are lacked for comparative analysis.
Meanwhile, the depth of the debris flow is measured by adopting the ultrasonic distance measuring sensor, so that the problem of inaccurate measurement data caused by liquid transparency and liquid level reflection in the force measuring process of the conventional laser distance measuring sensor is solved; the high-speed camera can shoot high-definition pictures before and after a plurality of dam body burst processes, and can be used for deformation fields before and after the model dam body burst. The synchronous data acquisition system acquires signals of a plurality of force plate acquisition sensors, a pore water pressure sensor and an ultrasonic distance measurement sensor through high-speed analog quantity acquisition and real-time continuous sampling, has multiple channels, can synchronously acquire the signals of the force plate acquisition sensors, the pore water pressure sensor and the ultrasonic distance measurement sensor, can synchronously trigger a high-speed camera, and is convenient for synchronously comparing image signals of a debris flow movement process with data signals of sensors of other types.
Drawings
To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. The drawings in the following description are examples of the invention and it will be clear to a person skilled in the art that other drawings can be derived from them without inventive exercise.
FIG. 1 is a schematic diagram of the apparatus of the present invention;
FIG. 2 is a general view of a configuration of the sink apparatus of the present invention;
FIG. 3 is a structural view of a water supply apparatus according to the present invention;
FIG. 4 is a schematic view of the surge triggering device, the buffering device and the energy dissipater of the present invention;
FIG. 5 is a schematic view of a wave-focusing design of an arc-shaped water tank;
fig. 6 is a wave-focusing effect of the arc-shaped water tank wave-focusing design: after the maximum surge height is designed through the arc-shaped water tank, the surge height is not attenuated any more;
figure 7 is a schematic view of a sink local instrumentation arrangement.
FIG. 8 is a schematic diagram of the micro pore pressure reserved slot hole position in the dam body of the moraine dam according to the present invention.
Fig. 9 is a schematic view of the installation position of the slidable triaxial-geophone synchronous monitoring module.
Fig. 10 is a design drawing of a slidable triaxial-geophone synchronous monitoring module, and a design drawing of a geophone signal filter cassette is arranged at the lower left corner.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making an invasive task, are within the scope of the invention.
The examples are given for the purpose of better illustration of the invention and are not intended to limit the scope of the invention. Therefore, those skilled in the art can make insubstantial modifications and adaptations to the embodiments of the present invention based on the disclosure set forth above, while remaining within the scope of the present invention.
Example 1
The invention relates to an experimental device and an experimental method for simulating the whole process of superdeep bursting disaster of a moraine lake caused by ice collapse and surge. The experimental device is provided with a six-position two-system for realizing the synchronous measurement of triggering, propagation, overtopping, disaster causing, evolution whole life, dynamic parameters, environmental noise vibration signals and imaging parameters in the whole process of ice collapse and surge in the ice lake burst, and comprises a water supply device, a surge triggering device, an energy dissipation device, a buffer device, an experimental water tank main body device, a collection device, a synchronous measurement system and a monitoring system.
The water supply device has the functions of flow supply, active regulation and control and flow monitoring. Referring to the attached figure 3, the water supply of the experimental system consists of three water pumps 100(0.5,1.0 and 1.5 kW) with different powers, and is simultaneously connected with a straight-through three-outlet PVC water pipe 300, wherein three pipe orifices are connected with the water pumps 100 with different powers and are water supply orifices of the whole experimental system; the three water pumps can be switched on and off simultaneously or in batches to realize the water supply of six levels (0.5,1.0,1.5,2.0,2.5 and 3.0kW) with different intensities. Two water valves 400 are arranged on the straight-through three-outlet PVC water pipe 300, and the water source of the straight-through three-outlet PVC water pipe mainly comes from the water storage tank 500. The right end of the water outlet of the pipe orifice is connected with an electromagnetic flowmeter 200 through a flange, and a rubber pad needs to be added in the middle of the flange to prevent water seepage from affecting the precision of the flowmeter. The electromagnetic flowmeter 200 is powered by 220V independent alternating current and is provided with an independent liquid crystal display screen, so that the volume flow of fluid passing through a pipeline can be displayed in real time. The right end of the water outlet of the electromagnetic flowmeter 200 is connected with a cast steel gate valve carbon steel high-temperature steam flange, so that the fine adjustment of the flow of the water outlet can be realized to offset the power virtual standard of a water suction pump or the flow fluctuation caused by head loss under the actual working condition. In addition, the electromagnetic flowmeter is ideally installed at a position where the flow state of the fluid upstream and downstream of the electromagnetic flowmeter is a single-phase stable flow, so that the influence of the local resistance pipe fittings on the flow state of the fluid upstream and downstream of the flowmeter does not directly influence the measurement accuracy of the flowmeter. Therefore, the electromagnetic flowmeter 200 needs to be arranged with attention to the arrangement of the straight pipe section with enough length, and the specific arrangement requirement can be adjusted according to the actual working condition, and the length is suitable and not suitable. The device is arranged to be 10D in front and 5D behind (D is the diameter of the pipeline). Due to the limitation of the working principle of the electromagnetic flowmeter, the flow rate under the working condition of 'full pipe' can be accurately measured. Therefore, the electromagnetic flowmeter needs to be installed on the water inlet side of the cast steel gate valve switch. During the experiment, can suitably close the delivery port of flange, reduce the flow in the pipeline by force and be used for guaranteeing 'full pipe' operating mode. The water outlet pipe of the electromagnetic flowmeter is directly connected with the water inlet of the water tank, so that the fluid with the accurately measured flow can flow into the water tank system with the minimum flow loss, and the experimental water supply inflow is ensured to have enough accuracy.
The surge triggering device, the buffering device and the energy dissipation device are matched for use, referring to the attached figure 4, and the excitation and the propagation of the ice collapse surge at different heights can be realized by replacing the simulation ice blocks 700 with different volumes. The surge triggering device is a T-shaped support 600 with adjustable height, the bottom end of the T-shaped support 600 is provided with a convex prismatic table (the table surface of the prismatic table only extends 5mm) for supporting the lower edge of the simulated ice block 700 (the simulated ice block 700 is made into a cuboid with the length, width and height of 0.5m multiplied by 0.42m multiplied by 0.18m by adopting a Polypropylene Plastic plate (Polypropylene Plastic) with the same density as the ice block, and the simulation of the ice collapse objects with different volumes can be realized by changing and setting different thicknesses of 0.06, 0.12 and 0.18 m); the cathode of the electromagnet embedded in the upper edge of the simulation ice block 700 can be closely adsorbed with the electromagnet of the anode on the T-shaped support, and the fixing function of the ice block before the ice collapse simulation is realized. When the experiment begins, the current in the electromagnet is cut off, the magnet loses magnetism, and the inertia moment of the simulated ice block 700 loses balance because the simulated ice block is only supported by an inner side fulcrum (a prismoid), so that the simulated ice block starts to rotate and fall, and the simulated ice block overturns to stimulate surging. Because the height of the water level in the water tank is only 0.4m, a buffer pool 800 with the depth of 0.2m is arranged right below the T-shaped support 600 in order to prevent ice cubes from falling down and touching the bottom of the water tank. Because the left end of the T-shaped frame 600 is close to one side of the end wall of the water inlet tank, in order to prevent the water waves from being transmitted to the left and being reflected by the touch wall to influence the rightward movement of the water waves, the experimental water waves are complicated and lose control, and the energy dissipater 900 (a metal mesh of a cuboid) is arranged on the left side of the T-shaped frame. The device can eliminate the leftward movement of water waves, can offset the impact of inflow of a water supply system, and reduces the influence of turbulent fluid on the hydrostatic reservoir on the right side of the water tank.
The water tank main body is matched with a synchronous measuring system and a monitoring system for use. Referring to the attached figure 1, the experimental water tank main body is divided into three sections, the length, the width and the height are as follows: the wave excitation propagation section (4m), the erosion simulation section (2.5m) of the tillite dam body and the debris flow movement monitoring section (2.5m) are respectively defined as 9m multiplied by 0.5 m. The three water tanks are connected through bolts, the joints are buffered by rubber pads, glass cement is coated for waterproof treatment, and the three water tanks are adjusted to be positioned on the same horizontal plane and are placed on a steel pipe support which is adjusted to be horizontal in advance. And after leveling, stamping wood plates with the same length and height are additionally arranged in the water tank, and the water tanks with different widths can be obtained by adjusting the positions of the stamping wood plates.
(1) Surge excitation and propagation section (4.0m)
Above the water tank of the surge excitation and propagation section, an ultrasonic distance sensor is configured at an interval of 0.4m from the original point, the ultrasonic distance sensor is fixed by matching a cross rod capable of rotating freely with tripods at two ends, and the sound wave generating surface is adjusted to be vertical to the bottom surface of the water tank and then screws in circular holes of the tripods are screwed down to fix the sensor. The number of the ultrasonic sensors is 9, including-01, -02, -03, -04, -05, -06, -07, -08, -09, and the layout drawing is shown in the attached drawing. Two pore pressure sensors are regularly arranged at the same positions when the dam is close to the dam foot, and seven pore pressure sensors A1, A2, A3, A4, A5, A6 and A7 are used for monitoring the movement characteristics of the maximum wave height of surge (shown in figure 1). In addition, the camera #2 and the camera #5 can be used for monitoring the wave shape of the surge wave in the water tank, and the two cameras are arranged in a staggered mode in order to eliminate measurement errors caused by the wide-angle effect of the cameras. In addition, the energy loss exists in the process of the propagation of the surge in the water tank, and the height of the surge wave is gradually reduced. In order to quantitatively control the energy loss in the propagation process, the embodiment of the invention adopts an arc-shaped water tank wall design (5), namely, the wave height is increased by narrowing the width of the water tank, so that the energy loss is counteracted. The experimental results show that the height of the swell remains unchanged as it propagates to the arcuate trough portion (fig. 6), demonstrating that the design has a better control over energy loss.
(2) Erosion simulation segment of ice tillite dam body (2.5m)
A circular hole with the diameter of 7mm is reserved on the inner side water tank wall of the erosion simulation section of the ice and moraine dam body (attached figure 8), and the circular hole can pass through a micro pore water pressure sensor and is pre-buried in the model ice and moraine dam body. The sensor probe extends out of the inner side of the water tank wall by 3cm, so that the real-time monitoring of the pore water pressure change in the dam body can be realized, and the seepage field before and after deformation can be calculated. 4 pore pressure sensor preformed holes are reserved at the bottom of the water tank, the pore positions are positioned on a central axis of the water tank, and the water level and pore pressure changes in the water tank can be measured in a non-contact mode by connecting the 4 pore pressure sensors to the outside of the water tank. In addition, a digital camera (a camera #3 and a camera #4) is respectively arranged on the axial line of the upstream slope surface and the downstream slope surface of the dam body for monitoring slope surface erosion; the front surface of the water tank is provided with a digital camera #1 for capturing the change of an erosion surface in the collapse process of the moraine dam body; a high-speed camera #11 can realize high-frequency automatic photographing (the photographing frequency is variable from 50Hz to 10000 Hz), and is used for calculating deformation fields before and after the crash by means of a Particle Image Velocimetry (PIV). A laser displacement sensor (laser-A4), an ultrasonic sensor (ultrasonic-06) and a digital camera #6 are arranged above the pore pressure sensor at the downstream dam foot and used for measuring the flow depth and the flow speed at the dam foot and converting the burst flow at the dam foot. In addition, 4 photographing shadowless lamps with the power of 50W are used for assisting the illumination system of the whole experimental water tank system. 4 little type shadowless lamp is used to the illumination basin 1 st section, and the light skew 45 illuminates the water face for the wave form that camera #2 and camera #5 shot is more obvious.
(3) Debris flow motion monitoring section (2.5m)
The mud-rock flow motion monitoring section is provided with three earth sound collection and power board stress collection synchronization measurement module preformed groove for install power board module and earth sound measurement module, the inslot is equipped with outstanding step, and two modules of being convenient for can freely remove (figure 7) in the basin on the transverse direction, in order to guarantee when adopting the basin experiment of different width, two modules can be in axis both sides position at any time, eliminate the boundary wall influence. The device can realize synchronous measurement and storage of dynamic parameters and environmental noise vibration signals on the same section in the debris flow movement process. Meanwhile, the top of the reserved groove is also provided with a laser displacement sensor, an ultrasonic distance sensor and a high-definition digital camera for recording the flow depth, the flow speed and the motion state of the fluid at the position of the module, and all collected data are synchronously transmitted to a synchronous measurement system of the water groove and recorded in a memory. Because the depth of flow in the experiment is shallow, consequently directly adopt the horizontal pole that can freely rotate and both ends weld the fixed ring at basin fixed position and carry out laser sensor, ultrasonic sensor and the fixed of camera. The front surface of the water tank is also provided with a digital camera #10 for recording the accumulation condition along the channel after the dam body is corroded, and the change rule of the accumulation condition of the channel along with time can be obtained by analyzing video data. In addition, stone materials with the same grading as the granular materials of the model dam body are uniformly smeared at the bottom of the water tank of the whole movement area (including the second half section of the second section of the water tank and the whole third section of the water tank) of the debris flow, and the stone materials are uniformly smeared and fixed at the bottom of the water tank by using epoxy resin so as to simulate the friction effect in the movement process of the debris flow in the real channel environment. In addition, 2 large 300W laser lamps were used to assist the illumination system of the entire experimental sink system to counteract the shadow problem when the dam was photographed by a high speed camera.
The collection device is the terminal garbage collection case of basin, and length width height size is: 1 m.times.0.5 m. 4 sides of collecting box and bottom surface material are the steel sheet of 0.2mm thick, and the square hole of 0.3m 0.2m is dug in advance to the box side, has installed 0.005 x 0.005 m's metal sieve in the hole for solid particle material in the filtration experiment waste water carries out garbage collection. The filtered wastewater is converged into a downstream large wastewater collection box (the length, width and height are 10m multiplied by 8m multiplied by 2m) to wait for centralized treatment, thereby avoiding water resource waste.
Example 2:
the method is used for simulating disaster evolution in the whole process of ice lake overtopping and bursting caused by natural ice collapse and surge, and specifically comprises the following steps (example 1):
(1) calibration sensor
Before the experiment, each sensor should be calibrated statically and dynamically. In the static calibration, firstly, an ultrasonic ranging sensor, a pore water pressure sensor and a force plate are calibrated; specifically, the pore water pressure sensor is calibrated by utilizing the pressure generated by static water heads at different heights, and the corresponding relation between the pore water pressure and a voltage signal is found; meanwhile, the positive stress in the force plate sensor can be calibrated by water heads with different heights, and mutual verification is carried out between the positive stress and the pore pressure sensor; calibrating the normal stress and the shear stress of the force plate by using the pressure generated by weights with different weights, and finding out the corresponding relation between the normal stress and the shear stress of the debris flow on the force plate and the voltage signal respectively; the sensor of the type is calibrated by utilizing different distances between the ultrasonic ranging sensor and the barrier, and the corresponding linear relation between the ultrasonic ranging sensor and the voltage signal is found. The miniature pore pressure sensor needs a vacuum pump to evacuate air in the permeable stone firstly, and then the porous stone is soaked into water quickly, so that water is sucked back to saturate the porous stone, and the purpose of removing the air in the porous stone is achieved. After repeating this operation several tens of times, the calibration of the pore pressure sensor in the normal flow may be started, which is not described again as described above. After the static calibration is completed, all sensors are installed at the appointed positions of the water tank, and dynamic calibration is performed on the earth sound sensors (which can only be dynamically calibrated) which are not calibrated. The dynamic calibration means that all the acquisition, monitoring and lighting equipment are opened by using the flow water supply of the fixed incoming flow, and the actual clear water flow velocity, the flow depth, the flow, the shearing force, the normal stress and the pore water pressure are converted through the result of the static calibration, so that the mutual verification and estimation error can be carried out. The vibration signal collected by the earth-sound equipment can be used as a basic environment noise signal for contrastively analyzing the debris flow vibration signal.
(2) Experimental apparatus arrangement
After the static calibration is completed, 5 ultrasonic sensors and 2 pore pressure sensors are installed at the first section of the water tank, the ultrasonic sensors are fixed by a tripod, and the pore pressure sensors are installed from the bottom of the water tank through reserved hole positions. The micro pore pressure sensor penetrates through a reserved hole position on the inner side of the water tank and extends out of the inner wall by about 3cm so as to prevent a transmission line of the pore pressure sensor from forming a reinforcement effect on the interior of the dam body and influencing the collapse process. And assembling the calibrated pore water pressure sensor and the force plate to form a force transducer module, installing the force transducer module in a reserved groove of the force plate module of the experimental water tank, and installing a ground sound module to enable the ground sound module to be positioned on two sides of the central axis and performing waterproof laminating treatment by using glass cement. The laser sensor and the ultrasonic distance sensor which are used for measuring the flow depth at the top of the module are fixed by a cross rod which can rotate freely, and a digital camera which is vertical to the bottom of the water tank is arranged at the same position for monitoring the flow speed. Setting the shooting speed and the shutter speed of the high-speed camera, adjusting the lens of the high-speed camera to the optimal position and adjusting the aperture size, and finally connecting the joints of the pore water pressure sensor, the force plate, the electromagnetic induction power supply signal line, the laser displacement sensor and the ultrasonic ranging sensor to the synchronous data acquisition system.
(3) Preparation of the experiment
1) Stacking the dam body on the geometric shape with a pre-drawn outline by adopting a layered stacking method for the experimental soil, and drawing the shape outline on the glass on one side of the water tank in advance through calculation; when the dam is piled up, the layers are tapped to a designated horizontal line by hands, and the compactness of the piled dam can be ensured by controlling the soil mass between each layer; the compactness of the whole model dam body can be relatively uniform by repeating the operation;
2) pre-placement of ice cubes of different volumes: in this experiment, a Polypropylene Plastic plate (Polypropylene Plastic) having the same density as ice cubes was used to make the length, width and height dimensions: 0.5 mx 0.42 mx 0.18m cuboid, the electromagnet embedded in the top of the cuboid can be tightly adsorbed on the T-shaped bracket. Before the experiment begins, the PP plate plastic is placed on the T-shaped support and is lifted to be electrified by the electromagnet, and the placing work of the ice blocks is finished;
3) and turning on all the sensors, and testing the response conditions of all the sensors. Using a lightproof square paper board to block signal sources of the ultrasonic sensor and the laser sensor in sequence, and observing whether the signal intensity on the synchronous acquisition system changes, wherein the change is a response; slightly pressing the probe of the micro pore pressure sensor by hand to observe whether the signal intensity on the synchronous acquisition system changes, wherein if the signal intensity changes, a response is obtained; the force plate module connected with the pressure plate is slightly pushed and pressed by hand to respectively test the response of the shear stress and the normal stress, and simultaneously, whether the signal intensity on the synchronous acquisition system changes or not is observed, and the change is the response; the bottom pore pressure sensor needs to be filled with water by the needle tube and then lightly pressed for testing so as to avoid the influence of air on pore pressure signals, and whether the signal intensity on the synchronous acquisition system changes or not is observed, and the change is a response.
(4) Initial experiment
After all sensors have been tested, the experiment can be started. When the experiment starts, the acquisition system is opened in advance and acquires a section of data to calibrate an initial value; then, a water supply system and a flow monitoring system are opened, the current flow can be displayed timely through reading on a display screen of the electromagnetic flowmeter, and the flow can be finely adjusted to the specified flow of the experiment through a flow flange on the right; when the water level in the water tank reaches 3/4 with a specified volume, closing a water supply system and throwing a large number of foam balls with the diameter of 5mm on the water surface to be used as tracer particles for capturing the change condition of the water surface waveform; after the lake surface is full of the tracer particles, the water supply system is opened again, the water level is added to the designated position by the same operation, and then the water supply is stopped. And then, triggering an electromagnet switch by using a collection system to release an ice block, wherein the ice block is rotated, collapsed, falls into water and is stimulated to surge, and the experiment formally starts.
(5) Cleaning up experiments
After the experiment was accomplished, the inside accumulational dam body material of basin need be cleared up with the shovel, still need clear up the inside silt of silting up of pore water pressure of basin bottom, prevents to cause the influence to the experiment next time. In addition, the silt on the surface of the micro pore pressure sensor also needs to be further cleaned. The dam material in the waste collection tank at the end of the sink can be emptied before the next experiment can begin.
While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and those skilled in the art can make various modifications without departing from the spirit and scope of the present invention.