56 results about "Submarine landslide" patented technology

The invention relates to a visual natural gas hydrate sediment mechanical property testing apparatus, belonging to the field of the measurement of basic natural gas hydrate physical properties. The visual natural gas hydrate sediment mechanical property testing apparatus mainly comprises an automatic-pressing triaxial apparatus main machine, an axial loading system, a confining pressure control system, a backpressure control system, a temperature control system, a data collection system and an X-ray CT (computed tomography) imaging system. The low-temperature high-pressure hydrate triaxial apparatus is organically combined with the X-ray CT imaging system, so that the testing on macro and micro mechanical properties of natural gas hydrate sediments can be synchronously carried out. The visual natural gas hydrate sediment mechanical property testing apparatus can simulate a stress state of a real reservoir stratum, macro and micro mechanical property data of the natural gas hydrate sediments can be acquired, the important significance on disclosing a deformation mechanism of the natural gas hydrate reservoir stratum and a triggering mechanism of geological hazards such as submarine landslide caused by the decomposition of natural gas hydrate can be realized, and an important guiding function for safely and high efficiently exploiting the natural gas hydrate can be realized.

The invention discloses a simulation and observation system for submarine landslide caused by natural gas hydrate decomposition. The simulation and observation system comprises a mechanical support, a heating decomposition unit and a deformation measurement unit, wherein the mechanical support is used for providing a platform and support for the heating decomposition unit and providing an observation area for the deformation measurement unit; the heating decomposition unit is used for heating an observed hydrate material so as to be decomposed and feeding back the amount of decomposition information to the deformation measurement unit; the deformation measurement unit is used for collecting a deformation signal in the mechanical support, observing the deformation process after the heating decomposition unit heats an observed test piece for decomposition according to the deformation signal, and obtaining the digital speckle images of the profile of the test piece in chronological order to generate the deformation information of the test piece for storage. The simulation and observation system solves the problems that in physical simulation experiments in a laboratory, the amount of decomposition and the decomposition area of material samples similar with a hydrate cannot be precisely controlled, the slope angle of the sample cannot be controlled, the landslide deformation cannot be quantitatively described and the like.

The invention discloses a piece of equipment for submarine landslide monitoring. The equipment comprises a long rod-shaped sealing housing. A magnetic sensing mechanism is arranged inside the sealing housing. The magnetic sensing mechanism comprises a movable rod and a measuring rod. The upper end of the measuring rod is provided with a hollow chamber. The lower end of the movable rod is clamped inside the hollow chamber in a rotatable way. The hollow chamber bottom is provided with a magnetic sensing chip. The lower end of the movable rod is fixedly provided with a magnetic induction sheet. A power supply module, a control module and a storage module are further arranged inside the sealing housing. The control module comprises a controller, a clock circuit and a relay. The equipment which has relatively good sensing measuring precision performs effective automatic monitoring and recording on multiple bedding planes of a seabed and monitors in a way to switch from a single-point way to a multi-point way to form a stereoscopic monitoring face. Direct-viewing data are provided for submarine landslide researches. Information supports for natural disasters such as landslides, earthquakes, tsunamis, etc. and early warning services thereof are provided. Meanwhile, the equipment which has the characteristics of convenient operation and low cost can be used for underwater monitoring for a relatively long time.

The invention relates to a testing device for simulating a submarine landslide and a testing method thereof. The invention aims to provide the testing device for simulating the submarine landslide which is simple in structure and convenient in operation and the testing method thereof. Through the technical scheme, the testing device for simulating the submarine landslide is characterized in that the testing device is provided with a model casing; the model casing is provided with a glass face convenient to observe the internal situation of the model casing; the model casing is internally provided with a slantly arranged slide rail; the lower end of the slide rail is rotatably connected with a supporting plate; the supporting plate is fixed to the model casing; the upper end of the slide rail is connected to the model casing through a slide rail inclination adjusting mechanism; the upper surface of the slide rail is covered with a cushion layer; a mudflow generating mechanism for releasing mud is arranged above the upper part of the slide rail; and a monitoring mechanism for monitoring the state of the mud on the slide rail is arranged corresponding to the slide rail. The testing device is applicable for the field of ocean engineering research.

Disclosed herein is an apparatus and method for simulating a submarine landslide. The apparatus includes an inclined flume; a plurality of sedimentary layers which are stacked on top of one another in the flume and tapped; water which is charged into the flume on the sedimentary layers in such a way that the surface of the water is formed in the flume; and a plurality of injectors which are provided in a bottom of the flume so as to be movable upwards or downwards with respect to the flume and inject gas or water into the sedimentary layer. The sedimentary layers are changed in pressure and temperature by the gas or water injected from the injectors into the sedimentary layers so that an artificial slope collapse is caused, whereby a water wave is generated in the flume.

The invention relates to a submarine landslide evolution process simulating system and experimental method based on transparent soil and a rotating water tank, and belongs to the technical fields of marine geological disasters and geotechnical engineering experiments. The simulating system comprises a rotating water tank system, a transparent soil simulating system and a control and data collection system. The rotating water tank system sets different speeds for a sample by means of a control motor, and a closed circular ring structure of a U-shaped section rotary drum groove satisfies that the sliding distance is not limited; the transparent soil simulating system prepares a transparent sample, with a tracer coloring agent, and fluid environment whose physical mechanical property is the same with that of a real submarine soil layer, so that the internal, external and water-soil interface is visualized in a 3D way in the whole sample evolution process; and the control and data collection system realizes quantitative monitoring and data extraction of the evolution process by means of 3D laser slicing and digital image collection. The provided system is controllable in the scale, visualized in the evolution process, capable of measuring image data, and can solve the problems that a long-distance evolution experiment is hard to carry out, data acquisition is difficult, and a monitoring picture is not clear.

The invention discloses a method for exploiting of submarine natural gas hydrate through solid replacement and pressure maintaining, and belongs to the field of energy and environments. The method comprises the steps that by arranging a stope at a hydrate layer, the stope temperature and pressure are monitored by using a temperature and pressure sensor and fed back to an offshore platform, existing conditions of the hydrate are maintained by adopting a sealing device according to a hydrate temperature and pressure curve, the hydrate is made to be not disintegrated, the solid form of the hydrate is maintained, solid-state mechanization mining, solid-liquid slurry conveying, gas separation and liquefaction transport are further conducted on the hydrate, a separated hydrate skeleton is brokenagain, and a cavity is filled after a rapid solidification material is added, thus destroy of submarine landslide, tsunami and a submarine ecological environment can be effectively prevented, and thepurpose of green exploiting is achieved. According to the method for exploiting of the submarine natural gas hydrate through solid replacement and pressure maintaining, the system is simple, and themethod is suitable for a hydrate pressure bearing layer with an upper impermeable cover layer and a lower impermeable cover layer, and has a good application prospect.

The invention belongs to the technical field of evaluation of influence of natural gas hydrate on environment. The invention discloses a numerical simulation prediction method and system for submarinelandslide induced by sea area natural gas hydrate decomposition, and the method comprises the steps: building a real natural gas hydrate system distribution model of a research area, predicting the upward movement depth of BSR when hydrate stabilization conditions are changed through the numerical simulation method, and determining the hydrate decomposition area and volume; based on a pore pressure calculation model, considering the volume change of the BSR underlying free gas along with the pressure before and after the hydrate is decomposed, and calculating the change of pore overpressure and effective stress in sediments caused by natural gas hydrate decomposition after the BSR is moved upwards; and mole-Coulomb strength criterion is used as a guide, and a finite element strength reduction method is adopted to calculate the stability safety coefficient of the slope, so that whether the submarine landslide can be induced by hydrate decomposition occurring when stable conditions arechanged is quantitatively predicted. The method has universality in other natural gas hydrate development areas.

The invention relates to a test device and a test method for simulating a submarine landslide impact structure. The method is mainly used for researching impact effect and the damage effect of the structure after undersea landslide instability damage. The device comprises four parts of a frame system, a lifting system, a soil bin system and a test system. A support protection and test space is provided for the whole device through the frame system. Angle adjustment of the slide way within a certain range is achieved through the lifting system. Stable storage and rapid release of simulated landslide substances are achieved through the soil bin system, and dynamic monitoring of the structure strain distribution rule and the change process in the landslide impact process is achieved through the test system. According to the invention, the actual damage phenomena of quick start and hydroplaning migration of the submarine landslide are fully restored, the influence of the distance between the structure and the submarine landslide on the impact effect is fully considered, the distance-adjustable physical model test device for the submarine landslide impact structure is realized, and thedefects of theoretical calculation and numerical simulation are avoided.

The invention provides a transparent soil deformation visualization system for simulating a submarine landslide, which comprises a transparent model test box, a model template, a CCD camera and a laser emitter, wherein the transparent model test box comprises a rectangular box body and a sealing cover; the sealing cover can seal the upper end opening of the rectangular box body; a vacuum pumping valve is arranged on the sealing cover; the model template has a plate-shaped structure as a whole; the model template and the inner wall of the rectangular box body form transparent soil space in a surrounding mode; a transparent soil slope body is arranged in the transparent soil space; and the CCD camera and the laser emitter are arranged outside the rectangular box body. The system can observethe landslide process, the structure is simple, and little manpower and few material resources are consumed in a single test.

The invention provides a device for underwater landslide detection. The device comprises a monitor end, a process end and a connection end, wherein the outside of the monitor end is provided with a plurality of sealed watertight protective layers, the inside of the monitor end is provided with a cavity, the cavity is provided with a MEMS sensor and sonar and damping disc, the MEMS sensor and sonar are fixedly on the cavity through the damping disc, the connection end comprises cable, one end of the cable is connected to the MEMS sensor and sonar in the monitor end, the other end of the cable is connected to the process end to transfer the data obtained from the monitor end to the process end and the cable is also used for supplying power to the monitor end. The process end comprises a data processor and a power module. The device is capable of effectively detecting the underwater landslide condition.

The invention discloses a seabed landslide evaluation method based on an indoor test. The method comprises preparation of structural soft clay and the indoor test. The preparation of the structural soft clay comprises the following steps: doping silicate 525 cement into marine soft soil, adding water to 2 times the liquid limit of a soil body, and uniformly stirring under a vacuum condition, thereby obtaining the structural soft clay, wherein the addition amount of the silicate 525 cement is 2% of the mass of the soft soil particles; the indoor test is realized based on a novel indoor test device for simulating seabed landslide. The device comprises a model box main body, a false slope, a funnel, a soil cutting plate, a sensor bracket and a portal frame lifting device. According to the method, test simulation of the submarine landslide with multiple slope angles and multiple working conditions can be achieved, the method can be combined with an indoor large section wave gutter channel,and the influence of the coupling effect of waves, slope toe scouring and rapid deposition on the submarine landslide is systematically researched, and the systematic method for evaluating the stability of the submarine landslide is obtained.

The invention discloses a computer method for simulating landslide vertical impact force borne by a submarine pipeline. According to the technical scheme, the method is characterized by comprising thesteps that 1, a three-dimensional model of the landslide vertical impact force borne by the subsea pipeline is established; 2, mesh generation is performed on the three-dimensional model, a non-repeated control volume exists around each mesh point, and a result is solved by utilizing a calculation equation; 3, model parameters are determined according to seabed sediment sampling and testing of the seabed landslide pre-judgment area; and 4, the obtained parameters are input into the model established in the step 2. The method provides technical reference for prediction and disaster preventiondesign of landslide disaster acting force on the submarine pipeline.

The invention discloses a variable-frequency vibration exploitation method of offshore gas hydrate and belongs to the technical field of offshore resource exploitation. The variable-frequency vibration exploitation method includes steps of drilling a methane gas hydrate reservoir layer via an offshore drilling rig, releasing stress energy to promote decomposing of gas hydrate by a vibrator at the top of a drill pipe, gathering the decomposed methane gas around drilling holes and enabling the methane gas to move upwards along the drill holes by means of natural pressure difference of the hydrate decomposing area and the drill holes; controlling rising speed of the methane gas, and collecting the methane gas from the drill holes to the drilling rig by a collector and storing. By adjusting energy of the vibrator, different frequencies of excitation energy are applied according to different saturation degrees of methane reservoir layers, the vibration energy can be adjusted according to decomposition of the methane gas, and decomposing speed and range of the gas hydrate can be effectively controlled; disasters such as unordered seabed landslide due to changes of depositional conditions are avoided.

The invention discloses an SPH simulation display method and system for a whole submarine landslide catastrophe evolution process. The method comprises the following steps: dispersing a calculation region of a submarine slope body and seawater into a set number of particles with different physical state attributes, and endowing each physical state particle with corresponding physical and mechanical parameters; on an outer side of a boundary, arranging a non-slip boundary layer in which repulsive particles and virtual particles are combined; applying infinite covering seawater gravity and periodic wave action to seawater particles, converting land slope acting force and structural acting force borne by the slope body into stress boundary conditions of a slope body particle calculation area, applying the stress boundary conditions to boundary particles composed of the repulsive particles and the virtual particles, and applying displacement boundary conditions; in each calculation time step, determining a catastrophe evolution stage of the submarine slope body, selecting a system constitutive equation set corresponding to the catastrophe evolution stage, carrying out calculation solving in the single time step, and completing updating of particle physical and mechanical information of a solving domain; and displaying the particle physical and mechanical information at set time steps.

The invention relates to a submarine landslide simulation system and test method based on a wave vibration effect, which are mainly used for researching dynamic response of submarine landslide under the wave vibration effect and revealing an inoculation mechanism and a damage mechanism of the submarine landslide. The system structurally comprises a frame supporting structure, a landslide simulation device, a wave simulation device and a landslide monitoring device. The landslide simulation mechanism comprises a simulation landslide body and an inclination angle adjusting mechanism, the wave simulation mechanism comprises a vibration excitation plate and a vibration excitation driving mechanism, and the landslide monitoring device comprises a pore pressure monitoring meter and a displacement sensor. According to the invention, the important effect of the wave load in the submarine landslide is fully considered, the defects of large harbor basin tests and theoretical numerical calculation are greatly overcome, and the system and the test method can be used for revealing an inoculation mechanism and a damage mechanism of the submarine landslide under the action of the wave load.

The invention provides a method for evaluating the stability of a seabed slope under the earthquake action based on in-situ monitoring. The method is used for evaluating the stability of a seabed landslide after an earthquake. By means of the method, under the condition that only a small amount of displacement in-situ monitoring equipment needs to be arranged, according to the displacement monitoring result, the seabed slope earthquake response process under the earthquake action is inverted, the seabed slope potential slip band strength reduction amount is calculated, the shear band expansion theory is combined, and the seabed slope stability after the earthquake action can be judged. The method is economical, feasible and theoretical, and can be used for submarine stability monitoring of ocean engineering such as submarine pipelines, offshore oil and gas platforms, offshore wind power and the like.

The embodiment of the invention discloses a natural gas hydrate mining method. The method comprises the steps that free gas in a natural gas hydrate mineral deposit is mined in a pressure reduction mining mode till the pressure of the natural gas hydrate mineral deposit is reduced to the preset percentage above the equilibrium pressure corresponding to the temperature of the hydrate mineral deposit, and the value range of the preset percentage is 5% to 10%; the temperature of the hydrate mineral deposit is reduced and kept below the freezing point, and thus free water in the mineral deposit is frozen; after the pressure and the temperature of the mineral deposit are stable, natural gas hydrate is mined; after mining of the natural gas hydrate is finished, CO2 is injected into the mineral deposit; and when CO2 injection is stopped, the temperature of the mineral deposit is increased to the freezing point or above. By utilizing the natural gas hydrate mining method, energy needed by mining can be reduced, the natural gas hydrate is mined safely in an environment-friendly mode, the stratum stability can be enhanced, and geological disasters such as stratum collapse and seabed landslide which possibly occur in the conventional mining process are effectively avoided.

The invention provides a submarine landslide process simulation method and system. The method comprises the following steps: carrying out meshless discretization on a submarine landslide body simulation region, constructing a landslide body particle model, and initializing physical and mechanical parameter values of the landslide body particles; constructing an adjacent particle tight branch domain of the landslide body particles, traversing the landslide body particles in the adjacent particle tight branch domain in each time step length to obtain a relative motion state among the landslide body particles and a stress tensor state of the landslide body particles, so as to judge a critical state of the landslide body particles and select a corresponding constitutive equation; according to the constitutive equation, obtaining a prediction-correction cycle result of a solid-liquid boundary density and pressure intensity, obtaining a density change rate, a stress change rate, and a momentum change rate of the landslide body particles, updating physical and mechanical parameter values of the landslide body particles according to the density change rate, the stress change rate and the momentum change rate of the landslide body particles, and within a set time step length, realizing effective simulation of the sliding and accumulation catastrophe process of a landslide body after a submarine landslide disaster occurs.

The invention provides a simulation experiment device and method for submarine landslide induced by natural gas hydrate decomposition, relates to the technical field of marine geological disasters and natural gas hydrate exploitation, and realizes dynamic observation of the submarine landslide process. The device comprises a model box body, a gas injection system, a landslide system, an observation system and a data acquisition and analysis system, the model box body provides a test platform and facilitates observation, the gas injection system simulates the process that natural gas hydrate is decomposed to release a large amount of methane gas through gas injection, and the landslide system is connected with the gas injection system. The landslide system comprises a permeation box, a clay layer and a simulated hydrate layer and is used for simulating a submarine landslide process, and the observation system records the simulated landslide process and monitors strain and stress changes in the landslide process; and the data acquisition and analysis system collects monitoring information of the pressure sensor and the high-speed camera. The device can be used for observing the dynamic process of hydrate-induced submarine landslide, and has the advantages of simplicity and convenience in operation, low cost and the like.

The invention relates to a wave maker for a submarine landslide physical model test and a working method. The wave maker comprises a bottom support, a vertically-arranged sliding rail is arranged on atop face of the bottom support, the sliding rail is slidably connected with a wave-making water tank; a top tank wall of the wave-making water tank is hinged with one end of a connecting rod; the other end of the connecting rod is hinged with a sliding block arranged on a swing arm; the sliding block is connected with an amplitude modulation driving piece arranged on the swing arm; the amplitudemodulation driving piece can drive the sliding block to move in the axis direction of the swing arm. The swing arm is connected with a driving mechanism; the driving mechanism is mounted on a top support which is fixedly arranged; the driving mechanism can drive the swing arm to rotate, the swing arm rotates to drive the wave-making water tank to move along the sliding rail through the connectingrod, the area of a top tank wall of the wave-making water tank is larger than that of a bottom tank wall, a side tank wall on one side of the wave-making water tank and the horizontal plane form an acute angle, and the wave maker can produce different types of waves and is high in applicability.

The invention discloses a submarine landslide deep deformation in-situ real-time monitoring device and analysis method, the device comprises a long hose, a monitoring unit, a processing unit and an upper computer, the monitoring unit comprises a plurality of monitoring subunits, and the processing unit comprises a data processor; and the monitoring subunits are installed in the long hose in the length direction of the long hose, the two ends of the long hose are sealed, each monitoring subunit comprises two mutually orthogonal MEMS accelerometers, the MEMS accelerometers in the long hose are connected with the data processor, and the data processor is connected with the upper computer. The device has the advantages that when the seabed stratum around the device changes, the long hose is driven to bend and move, the MEMS accelerometer can move along with the overall movement of the device, the accelerometers at different levels can transmit own attitude information to the data processor, and the attitude information is analyzed and processed by the data processor and transmitted to the upper computer; and finally, the upper computer carries out visualization processing, and reconstructs and displays the stratum deep displacement deformation information.