CN114324820A - Test device for simulating overall process of weakening of seabed gas-containing slope and landslide - Google Patents

Abstract

The invention discloses a test device for simulating the whole process of weakening of a gas-containing slope in the sea bottom and generating landslide, which comprises the following components: the device comprises a model box, a gas-containing slope and a gas-containing seabed connected with the gas-containing slope are arranged in the model box; the tidal trigger comprises a power device and a gas regulator, wherein a piston matched with the gas regulator in shape is arranged in the gas regulator, the piston is connected with the power device through a dowel bar, the gas regulator is divided into an upper space and a lower space which are not communicated with each other by the piston, and the lower space is communicated with the model box; and the gas separation structure comprises a high-pressure gas cylinder, a vent pipeline and a gas diffusion pipeline which are sequentially connected, and the output end of the gas diffusion pipeline is arranged in the gas-containing slope. The invention simulates the whole process of weakening and landslide of the seabed gas-containing slope under the condition of tidal load and gas separation, and is used for researching the stability problem of the seabed gas slope triggered by multiple factors.

Description

Test device for simulating overall process of weakening of seabed gas-containing slope and landslide

Technical Field

The application relates to application of a hypergravity experiment technology in the field of ocean rock and soil, in particular to a test device for simulating the whole process of weakening of a submarine gas-containing slope and landslide.

Background

The scale of major offshore engineering construction in the future decade of the Hangzhou gulf is the first of China, and seabed foundation soil is the final carrier of the engineering construction. The hangzhou bay, one of the three major tidal bays in the world, has free microbubbles distributed widely in the shallow silt seabed foundation. Under the action of the cyclic reciprocation of extreme expansion and falling tide, gas in the seabed is alternately dissolved and separated out, so that the strength deterioration of the seabed foundation soil framework is aggravated, and the frequent occurrence of offshore landslide is promoted, thereby bringing huge hidden troubles to the offshore major engineering construction.

Currently, most of the research aiming at the problems is in a field test stage or a small scale test under the condition of normal gravity.

In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art:

the huge financial resources and material resources consumed by the field experiment are uneconomical and long in time consumption. On the other hand, the small scale test under the normal gravity cannot ignore the influence of the scale effect, and the obtained result is far from the actual situation.

Disclosure of Invention

The embodiment of the application aims to provide a test device for simulating the whole process of weakening of a submarine gas-containing slope and generation of a landslide, so as to solve the technical problem of influence of a scale effect in a normal gravity test in the related art.

According to a first aspect of the embodiments of the present application, a test device for simulating the whole process of weakening of a sea floor gas-containing slope and landslide generation is provided, which includes:

the device comprises a model box, a gas-containing slope and a gas-containing seabed connected with the gas-containing slope are arranged in the model box;

the tidal trigger comprises a power device and a gas regulator, a piston matched with the gas regulator in shape is arranged in the gas regulator, the piston is connected with the power device through a dowel bar, the piston divides the gas regulator into an upper space and a lower space which are not communicated with each other, and the lower space is communicated with the model box; and

the gas separation structure comprises a high-pressure gas cylinder, a vent pipe and a gas diffusion pipe which are sequentially connected, and the output end of the gas diffusion pipe is arranged in the gas-containing slope.

Further, the wave generator is used for generating wave load and is arranged on the side wall, opposite to the slope, in the model box.

Further, the vibration table for manufacturing the seismic load is also included.

Further, the vibrating table comprises a table top for bearing the model box, a guide rail for enabling the model box to freely move in the vibrating operation direction and a vibration exciter for manufacturing seismic load, an elastic part is arranged between the table top and the guide rail, and the output end of the vibration exciter is connected with the table top.

Further, the vibration exciter comprises:

a cylinder body;

the output end of the piston rod is connected with the table top;

the output end of the sealing tube is connected with the input end of the piston rod, and the sealing tube is connected with a force sensor used for acquiring the numerical value of the axial force in the piston rod.

Further, the top of the mold box is provided with a beam and a reaction frame for suspending and fixing the mold box for centrifugation.

Further, the piston includes a pressure bearing disk for bearing pressure transmitted by the power unit and a buoyancy disk for keeping the piston in a floating state under the pressure of the power unit, wherein the buoyancy disk is in close contact with a sidewall of the gas regulator to prevent water in the lower space from entering the upper space.

Further, the lower space is connected with the model box through a pressure control pipe.

Further, valves are arranged on the air vent pipeline and the air dispersing pipeline.

Further, the device also comprises a plurality of pore pressure meters for measuring the pore water pressure of the air-containing slope and bending elements for measuring the wave speed, wherein the pore pressure meters and the bending elements are arranged in the air-containing slope along the slope extending direction;

the device also comprises a deformed pile arranged at the toe of the air-containing slope, wherein a displacement measuring device for measuring the toe displacement of the air-containing slope is arranged on the deformed pile;

a soil moisture sensor for measuring the moisture of the air-bearing slope;

the pressure gauge is used for measuring the water pressure in the lower space;

the system also comprises a particle image velocimeter for recording the vector displacement of the silt particles in the air-bearing slope;

the system is characterized by further comprising a camera module for recording the experimental process, wherein the camera module comprises a first camera for recording the state change of the slope soil body in the experimental process, a second camera for recording the displacement state of the soil body at the deformed pile and the slope toe in the experimental process and a network camera for monitoring the experimental process in real time.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

according to the embodiment, the air-containing slope and the air-containing seabed connected with the air-containing slope are arranged in the model box, the tide rising and the tide falling are realized through the tide trigger, the tide manufacturing is stable, and the tide period can be controlled; when the tide is manufactured, the liquefaction process of the air-containing seabed under the storm tide can be simulated, and the influence of the water level change under the storm tide on the stratum is revealed; the gas can be released from different angles through the gas separation structure, and the influence of the gas separation in the slope on the slope during the rising and falling tide is simulated; waves are manufactured through a wave making machine, so that the liquefaction characteristic of the slope under the wave load is researched; the vibration load is manufactured through the vibrating table, the generation of earthquake is simulated, and the influence of the earthquake load on the stability of the coastal gas-containing slope is researched. In a word, this application has adopted hypergravity centrifuge experimental model, has overcome the technical problem that the influence of scale effect can not be neglected under the ordinary gravity experimental condition, has realized that the experiment of going on in the laboratory obtains the result identical with the field experiment, can save experimental time and a large amount of funds and manpower like this.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and together with the description, serve to explain the principles of the application.

Fig. 1 is a schematic structural diagram of a test apparatus for simulating the whole process of weakening a submarine aerated slope and generating landslide according to an exemplary embodiment.

FIG. 2 is a schematic diagram of the structure of a tidal trigger shown in accordance with an exemplary embodiment.

FIG. 3 is a top view of a test rig for simulating the overall process of weakening a subsea air-bearing slope, landslide production, according to an exemplary embodiment.

The reference numerals in the figures include:

100. a model box; 110. an air-bearing ramp; 111. a pore pressure meter; 112. a bending element; 113. a soil humidity sensor; 120. a gas-containing seabed; 130. a cross beam; 140. a reaction frame; 150. deforming the pile; 151. a displacement measuring device; 160. positioning angle steel; 200. a tidal trigger; 210. a power plant; 220. a gas regulator; 221. an upper space; 222. a lower space; 223. a pressure gauge; 230. a piston; 231. a pressure bearing disc; 232. a buoyancy disc; 240. a pressure control pipe; 250. a dowel bar; 300. a gas evolving structure; 310. a high pressure gas cylinder; 311. a barometer; 320. an air duct; 321. a valve; 330. a gas dispersion pipe; 400. a wave making machine; 500. a vibration table; 510. a table top; 520. a guide rail; 530. a vibration exciter; 531. a cylinder body; 532. a piston rod; 533. a sealing tube; 540. an elastic member; 550. a force sensor; 600. a particle image velocimeter; 700. a camera module; 710. a first camera; 720. a second camera; 730. a network camera; 740. a floodlight.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It is to be understood that although the terms first, second, third, etc. may be used herein to describe various information, such information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. The word "if" as used herein may be interpreted as "at … …" or "when … …" or "in response to a determination", depending on the context.

FIG. 1 is a block diagram of a test rig for simulating the overall process of weakening a sea floor gas-bearing slope and producing landslide, according to an exemplary embodiment, as shown in FIG. 1, the rig may include: the tidal trigger comprises a model box 100, a tidal trigger 200 and a gas evolution structure 300, wherein an air-containing slope 110 and an air-containing seabed 120 connected with the air-containing slope 110 are arranged in the model box 100; the tidal trigger 200 comprises a power device 210 and a gas regulator 220, wherein a piston 230 matched with the shape of the gas regulator 220 is arranged in the gas regulator 220, the piston 230 is connected with the power device 210 through a dowel bar 250, the piston 230 divides the gas regulator 220 into an upper space 221 and a lower space 222 which are not communicated with each other, and the lower space 222 is communicated with the model box 100; the gas separation structure 300 comprises a high-pressure gas cylinder 310, a vent pipe 320 and a gas dispersion pipe 330 which are connected in sequence, wherein the output end of the gas dispersion pipe 330 is arranged in the gas-containing slope 110.

According to the embodiment, the air-bearing slope 110 and the air-bearing seabed 120 connected with the air-bearing slope 110 are arranged in the model box 100, and the tide rising and the tide falling are realized through the tide trigger 200, so that the tide manufacturing is stable, and the tide cycle can be controlled; while the tide is manufactured, the liquefaction process of the air-containing seabed 120 under the storm surge can be simulated, and the influence of the water level change under the storm surge on the stratum is revealed; the gas can be released from different angles through the gas separation structure 300, and the influence of gas separation in the slope on the slope during rising and falling tide is simulated; waves are produced through the wave maker 400, so that the liquefaction characteristic of the slope under the wave load is researched; the vibration load is manufactured through the vibration table 500, the generation of the earthquake is simulated, and the influence of the earthquake load on the stability of the coastal gas-containing slope 110 is researched. In a word, this application has adopted hypergravity centrifuge experimental model, has overcome the technical problem that the influence of scale effect can not be neglected under the ordinary gravity experimental condition, has realized that the experiment of going on in the laboratory obtains the result identical with the field experiment, can save experimental time and a large amount of funds and manpower like this.

Specifically, the power device 210 may be a hydraulic cylinder or a hydraulic jack.

Specifically, a wave maker 400 for making wave loads is further included, the wave maker 400 being disposed on a side wall of the mold box 100 opposite the slope.

In an embodiment, the wave maker 400 may be a push plate type wave maker 400, and the push plate type wave maker 400 includes a motor, a transmission shaft, and a wave making plate, which are connected in sequence, wherein the motor applies power to the transmission shaft to enable the wave making plate to move horizontally, so as to make a wave load;

in another embodiment, the wave generator 400 may be a rocking plate type wave generator 400, and the lower end of the moving component (wave generating plate) of the wave generator 400 is constrained on a shaft and can rotate around the shaft by a certain angle, and the water body state can be changed by the forward and backward swinging. The oscillation amplitude of the wave making plate determines the wave height of the generated waves, and the oscillation frequency of the wave making plate determines the frequency and wavelength of the waves.

Specifically, a vibration table 500 for creating seismic loads is also included.

Further, the vibration table 500 includes a table 510 for supporting the mold box 100, a guide rail 520 for allowing the mold box 100 to freely move in a vibration operation direction, and an exciter 530 for generating a seismic load, wherein an elastic member 540 is disposed between the table 510 and the guide rail 520, an output end of the exciter 530 is connected to the table 510, the piston rod 532 is controlled by the exciter 530 to reciprocate left and right, the vibrating table 510 is linked to generate a horizontal movement, different types of seismic waves can be generated by controlling a movement frequency of the piston rod 532, so that the experimental mold box 100 generates a vibration similar to a seismic action, and in a specific implementation, the elastic member 540 may be a spring or a rubber with elastic force.

Further, the vibration exciter 530 comprises a cylinder 531, a piston rod 532 and a sealing tube 533, wherein an output end of the piston rod 532 is connected with the table-board 510; the output end of the sealing tube 533 is connected with the input end of the piston rod 532, the sealing tube 533 is connected with a force sensor 550 for acquiring the numerical value of the axial force in the piston rod 532, in specific implementation, a motor inside the sealing tube 533 pushes the piston rod 532 to reciprocate to produce seismic load and drive the table top 510 to vibrate, meanwhile, the force sensor 550 at the rear part of the sealing tube 533 can transmit the numerical value of the axial force in the piston rod 532 in real time, and the type and the size of the simulated seismic load are reflected through the numerical values.

Specifically, the top of the mold box 100 is provided with a cross beam 130 and a reaction frame 140 for suspending and securing the mold box 100 for centrifugation, and the cross beam 130 and the reaction frame 140 can precisely position the mold box 100 above the cantilever of the centrifuge.

As shown in fig. 2, in particular, the piston 230 includes a pressure bearing plate 231 for bearing the pressure transmitted by the power device 210 and a buoyancy plate 232 for keeping the piston 230 floating under the pressure of the power device 210, wherein the buoyancy plate 232 is closely attached to the sidewall of the gas regulator 220 to prevent the water in the lower space 222 from entering the upper space 221, and the power device 210 controls the piston 230 to move, so that the water in the lower space 222 enters and exits the mold box 100, thereby simulating the change of tide.

In one embodiment, the pressure-bearing plate 231 is an acrylic disc, the buoyancy plate 232 is a foam plate with strong buoyancy, the pressure-bearing plate 231 made of acrylic has high strength and low mass, and the foam with strong buoyancy has strong hydrophobicity and can generate strong reverse action.

Specifically, the lower space 222 is connected to the mold box 100 through a pressure control pipe 240, and the pressure control pipe 240 may be used not only to transfer water between the lower space 222 and the mold box 100, but also to transfer gas that is not dissolved in the mold box 100 to the lower space 222 for storage.

Specifically, the vent pipe 320 and the air dispersion pipe 330 are provided with valves 321, and the valves 321 are used for controlling the angle and the position of the gas release and adjusting the pressure of the high-pressure gas cylinder 310 to control the gas release rate.

Further, the device also comprises a plurality of pore pressure meters 111 for measuring the pore water pressure of the air-containing slope 110 and a bending element 112 for measuring the wave velocity, wherein the pore pressure meters 111 and the bending element 112 are arranged in the air-containing slope 110 along the slope extending direction, the bending element 112 consists of a transmitting element and a receiving element, and the measured wave velocity can be used for reversely pushing the soil stiffness;

the device is characterized by further comprising a deformed pile 150 arranged at the toe of the air-bearing slope 110, wherein a displacement measuring device 151 used for measuring the toe displacement of the air-bearing slope 110 is arranged on the deformed pile 150, the displacement of the soil body at the toe is measured through the displacement measuring device 151, and the state of the soil body at the toe when the landslide is generated is judged so as to obtain part of basis for judging the landslide;

the device also comprises a soil humidity sensor 113 for measuring the humidity of the air-containing slope 110, and is used for recording the humidity of a slope soil body in the experimental process as an observation data for recording; in a specific implementation, a VH400 series soil moisture sensor 113 is used, with a VH400 moisture 94mm long probe, which outputs a dc voltage proportional to the water content.

A pressure gauge 223 is also included for measuring the water pressure in the lower space 222, and when the tidal trigger is activated, the power plant 210 needs to be regulated by the indication of the pressure gauge 223 to generate the tidal conditions required for planning.

A particle image velocimeter 600 for recording the vector displacement of the silt particles in the gas-bearing ramp 110 is also included for tracking the movement of the ramp behind the glass window. The technique tracks the texture of the earth between successive images to provide a displacement vector increment for the block.

As shown in fig. 1 and fig. 3, the system further comprises a camera module 700 for recording the experimental process, wherein the camera module 700 comprises a first camera 710 for recording the state change of the slope soil body in the experimental process, a second camera 720 for recording the displacement state of the deformed pile 150 and the soil body at the slope toe in the experimental process, and a network camera 730 for monitoring the experimental process in real time, in an embodiment, the first camera 710 is a GoPro camera, and the second camera 720 is a canon G7 camera.

Preferably, the camera module 700 further comprises a plurality of floodlights 740, and the floodlights 740 can shine into the model box 100 to ensure that the camera and the webcam 730 can work normally.

In specific implementation, the mold box 100 has a reinforced top plate on the upper bottom surface and a reinforced bottom plate on the lower bottom surface, and since the water pressure in the mold box 100 may reach the MPa level, the reinforced top plate and the reinforced bottom plate are required to ensure that the shape of the mold box 100 is not deformed, and the side walls are made of transparent organic glass, so that the camera module 700 can shoot the mold box 100 through the transparent organic glass, and can also bear the water pressure in the mold box 100 to prevent cracking.

Preferably, a positioning angle 160 is provided between the side wall of the mold box 100 and the reinforced top plate for positioning the mold box 100 when the centrifuge is cantilevered.

In one embodiment, the mold box 100 has a length of 80m, a width of 60m, and a height of 55m, and the scale bars of the samples in the mold box 100 are all 1: 100, the centrifuge was operated at 100 times gravity for the test.

The use process of the test device for simulating the whole process of weakening the seabed gas-containing slope 110 and generating the landslide is as follows:

model experiments were performed on a centrifuge turntable. The material in mold box 100 is prepared, the slope is made, and deformed pile 150 is installed. The mold box 100 is secured to the centrifuge boom. The centrifuge is started after opening the port of the model box 100, starting the data acquisition system for about half an hour. The experiment level is adjusted, and the height of the safe box pressure sensor is higher than that of the cylinder base. Each time the load of the mold box 100 was changed, a time of 15 minutes was given to allow the gas to be dissolved or removed from the solution.

The tidal trigger 200 and the power device 210 drive the piston 230 in the gas regulator 220 to move up and down through the dowel 250, and then the water in the lower space 222 enters and exits the mold box 100, so that the water pressure in the mold box 100 changes.

The wave maker 400 can make regular waves and irregular random waves, and the control system controls the movement of the wave making push plate to generate expected waveforms. The specific process is as follows: the control system drives the motor to rotate, the motor drives the push plate to reciprocate, and the push plate pushes water in the model box 100 to generate waves. When the rotating speed and the rotating direction of the motor are changed, the motion amplitude and the frequency of the push plate are changed. And opening the wave making device, and periodically reciprocating the wave making plate back and forth to push the water body, so that the state of the water body is changed to generate waves. The maximum stroke and speed of the wave making plate determine the wave height, and the motion frequency of the wave making plate determines the wave period.

A plurality of air dispersing pipelines 330 are embedded in the soil body of the model box 100, air dispersing holes are formed in the air dispersing pipelines 330, and air is sprayed from the air dispersing holes, so that the influence of gas separation in the occurrence process of a submarine landslide disaster can be simulated. The valves 321 on the vent line 320 and the gas dispersion line 330 control the angle and position of gas release, and the pressure of the high pressure gas cylinder 310 is adjusted to control the gas release rate.

The earthquake simulation shaking table 500 starts the vibration exciter 530, and the piston rod 532 reciprocates left and right to drive the shaking table surface 510 to shake, so that various types of earthquake waves are realized, and the model box 100 can vibrate under the similar earthquake action.

Other embodiments of the present application will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the application being indicated by the following claims.

It will be understood that the present application is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims (10)

1. The utility model provides a simulation seabed contains gas slope weakening, landslide and produces test device of overall process which characterized in that includes:

the device comprises a model box, a gas-containing slope and a gas-containing seabed connected with the gas-containing slope are arranged in the model box;

the tidal trigger comprises a power device and a gas regulator, a piston matched with the gas regulator in shape is arranged in the gas regulator, the piston is connected with the power device through a dowel bar, the piston divides the gas regulator into an upper space and a lower space which are not communicated with each other, and the lower space is communicated with the model box; and

the gas separation structure comprises a high-pressure gas cylinder, a vent pipe and a gas diffusion pipe which are sequentially connected, and the output end of the gas diffusion pipe is arranged in the gas-containing slope.

2. The apparatus of claim 1, further comprising a wave generator for generating wave loads, the wave generator being disposed on a side wall of the mold box opposite the ramp.

3. The apparatus of claim 1 further comprising a vibration table for creating seismic loads.

4. An apparatus according to claim 3, characterized in that the vibrating table comprises a table top for carrying the mould box, a guide rail for allowing the mould box to move freely in the direction of vibration travel, and an exciter for creating a seismic load, an elastic element being arranged between the table top and the guide rail, the output end of the exciter being connected to the table top.

5. The apparatus of claim 4, wherein the exciter comprises:

a cylinder body;

the output end of the piston rod is connected with the table top;

the output end of the sealing tube is connected with the input end of the piston rod, and the sealing tube is connected with a force sensor used for acquiring the numerical value of the axial force in the piston rod.

6. The apparatus according to claim 1, characterized in that the mould box top is provided with crossbeams and reaction frames for suspending and fixing the mould box for centrifugation.

7. The apparatus of claim 1, wherein the piston comprises a pressure bearing disk for bearing pressure transmitted by the power plant and a buoyancy disk for maintaining the piston in a floating state under the pressure of the power plant, wherein the buoyancy disk is in close contact with a sidewall of the gas regulator to prevent water in the lower space from entering the upper space.

8. The apparatus of claim 1, wherein the lower space is connected to the mold box by a pressure control pipe.

9. The apparatus of claim 1, wherein valves are provided on the vent conduit and the air dispersion conduit.

10. The device of claim 1, further comprising a plurality of pore pressure gauges for measuring pore water pressure of the gas-containing slope and bending elements for measuring wave velocity, wherein the pore pressure gauges and the bending elements are arranged in the gas-containing slope along a slope extending direction;

the device also comprises a deformed pile arranged at the toe of the air-containing slope, wherein a displacement measuring device for measuring the toe displacement of the air-containing slope is arranged on the deformed pile;

a soil moisture sensor for measuring the moisture of the air-bearing slope;

the pressure gauge is used for measuring the water pressure in the lower space;

the system also comprises a particle image velocimeter for recording the vector displacement of the silt particles in the air-bearing slope;

the system is characterized by further comprising a camera module for recording the experimental process, wherein the camera module comprises a first camera for recording the state change of the slope soil body in the experimental process, a second camera for recording the displacement state of the soil body at the deformed pile and the slope toe in the experimental process and a network camera for monitoring the experimental process in real time.

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