A simulated hypergravity slope model test device and method

Abstract

The present invention relates to a novel simulated supergravity slope model test device, comprising: a model box, a loading mechanism and a friction mechanism, wherein the model box is used to load the slope model; the top, front side and rear side of the model box are all set to be open; the loading mechanism is used to apply a horizontal load to the slope model to provide the normal pressure required for friction; the friction mechanism is used to generate a vertical downward friction force on the slope model to simulate the gravity field of the rock slope. The test device can reproduce the stress and strain characteristics of the on-site slope more realistically through the friction equivalent to gravity, providing good preconditions for indoor simulations such as rainfall, excavation and blasting, effectively solving the problems of complex operation and insufficient simulation of current model tests, and providing a new idea for slope model test research.

Description

Technical Field

[0001] The invention relates to the technical field of slope model test equipment, and in particular to a simulated hypergravity slope model test device and method. Background Art

[0002] Landslide is a geological disaster that occurs frequently in mountainous areas. In my country, landslides cause a large number of casualties and economic losses every year. Therefore, the study and prevention of landslides has become a very important research topic. Physical simulation of slope instability is an important means to study the deformation and failure process of slope rock mass. Many scholars have studied the deformation and failure process and formation mechanism of slopes through physical simulation methods.

[0003] So far, slope model tests mainly include ordinary 1g model tests and Ng centrifugal model tests. Ordinary 1g model tests are carried out under 1g gravity acceleration. Since the geometric size of the model is several times smaller than that of the prototype, the stress level of the model under normal gravity conditions is quite different from that of the prototype; in addition, the deformation and failure characteristics of the slope model are very small and difficult to observe.

[0004] The Ng centrifuge model test places the model in a high-speed rotating centrifuge and makes the model bear centrifugal acceleration greater than the gravity acceleration to compensate for the loss of the actual slope's deadweight due to the reduction in the model size. The inertial force is equivalent to gravity, so the model and the prototype have equal stress and strain, similar deformation, and the same failure mechanism, which can reproduce the prototype characteristics and thus better predict the slope deformation and failure characteristics. However, when conducting subsequent research on the slope, the centrifuge test needs to be stopped and then the slope model is subjected to rainfall, excavation and other working conditions, which is inconsistent with the actual stress path of the project, resulting in distorted test results. Summary of the invention

[0005] The present application provides a simulated hypergravity slope model test device and method, which solves or partially solves the technical problem that the prior art cannot impose rainfall and excavation conditions on the slope model while the centrifuge test is ongoing, which is inconsistent with the actual stress path of the project and leads to distorted test results; it realizes the provision of a simulated hypergravity slope model test device that can be used to simulate the hypergravity field of the on-site slope, providing a new idea for slope model test research.

[0006] The present application provides a simulated hypergravity slope model test device, comprising: a model box, a loading mechanism and a friction mechanism, wherein:

[0007] The model box is used to load the slope model; the top, front side and rear side of the model box are all set to be open;

[0008] The loading mechanism is used to apply a horizontal load to the slope model to provide a normal pressure required for friction;

[0009] The friction mechanism is used to generate a vertical downward friction force on the slope model to simulate the gravity field of the rock slope.

[0010] Preferably, the slope model is formed by stacking prefabricated blocks with barite powder, quartz sand and iron powder as aggregates.

[0011] Preferably, the model box is fixed on the base via vertically arranged pillars; the pillars are retractable structures.

[0012] Preferably, the right side of the model box is configured as a semi-closed structure.

[0013] Preferably, the loading mechanism is arranged at the front side of the model box, and the loading mechanism comprises: a hydraulic device, a cylinder and a pressing plate,

[0014] The hydraulic device is connected to the oil cylinder via an oil pipe to deliver high-pressure oil to the oil cylinder;

[0015] The piston rod of the oil cylinder is connected to the pressing plate, and the pressing plate is arranged corresponding to the front side of the model box; the oil cylinder drives the pressing plate to apply horizontal compressive stress to the slope model.

[0016] As a preferred embodiment, it also includes: a tempered glass plate and a plastic film,

[0017] The tempered glass plate is movably arranged at the front side of the model box; the pressure plate is fixed on one side of the tempered glass plate, driving the tempered glass plate to move linearly between the front side and the rear side of the model box, so that the tempered glass plate applies horizontal compressive stress to the slope model;

[0018] The plastic film is arranged between the tempered glass plate and the slope model.

[0019] Preferably, it further comprises a plurality of micro pressure boxes arranged at the front side of the slope model; the micro pressure boxes are connected to a resistance strain tester to send the normal pressure value applied on the slope model to the resistance strain tester.

[0020] Preferably, the friction mechanism is arranged at the rear side of the model box, and the friction mechanism comprises: a friction belt, two rotating shafts, a conveyor belt, a speed reduction mechanism and a motor.

[0021] The friction belt is arranged close to the rear side of the slope model, and the friction belt is tightened by the rotating shafts at both ends;

[0022] The two rotating shafts are fixed on the wall through the friction belt supports;

[0023] One of the rotating shafts is connected to the speed reduction mechanism via the conveyor belt;

[0024] The speed reduction mechanism is connected to the electric motor.

[0025] Based on the same inventive concept, the present application also provides a simulated hypergravity slope model test method, which is implemented by the simulated hypergravity slope model test device and includes the following steps:

[0026] Determine the physical property parameters and geometric parameter indicators of the slope model according to the similarity ratio, determine the mix ratio of similar materials through mechanical tests, and configure the similar materials;

[0027] The slope model of the experimental design is constructed by stacking the similar materials;

[0028] According to the Ng gravitational acceleration of the slope model designed by the experiment and the friction coefficient between the slope model and the friction mechanism, applying a normal pressure to the front side of the slope model through the loading mechanism;

[0029] Applying a vertical downward friction force to the slope model through the friction mechanism to simulate the supergravity of the slope model;

[0030] After the supergravity simulation of the slope model is realized, the rainfall, blasting vibration and excavation test process of the slope model is continued.

[0031] Preferably, when the slope model is being built, a displacement sensor and a water content sensor are buried in the slope model.

[0032] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0033] This application establishes a simulated hypergravity slope model test device consisting of a model box, a loading mechanism and a friction mechanism, which can be used to simulate the hypergravity field of the on-site slope, providing a new idea for slope model test research. By establishing a lateral friction mechanism to provide the slope with vertical downward friction and equivalent self-weight stress, the stress condition of the on-site slope is truly simulated, solving the problem that the deformation and damage phenomenon of the 1g model test is not obvious and the Ng centrifugal model test needs to stop the centrifuge to apply other working conditions, resulting in stress path distortion.

[0034] The device and test method are easy to operate, providing a solid foundation for subsequent slope model tests under different working conditions such as rainfall and excavation, making the model test results more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 A schematic diagram of the structure of a simulated hypergravity slope model test device provided in an embodiment of the present application;

[0037] Figure 2 A schematic diagram of the structure of the slope model provided in the embodiment of the present application in cooperation with the pressure plate, the tempered glass plate and the friction belt.

[0038] (The components represented by the reference numerals in the attached drawings are: 1 model box; 2 base; 3 pillar; 4 slope model; 5 friction belt; 6 rotating shaft; 7 friction belt support; 8 wall; 9 transmission shaft; 10 conveyor belt; 11 speed reduction mechanism; 12 motor; 13 bracket; 14 bolt; 15 gasket; 16 pressure plate; 17 piston; 18 oil cylinder; 19 support; 20 oil pipe; 21 hydraulic equipment; 22 tempered glass plate; 23 plastic film; 24 micro pressure box) DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0040] See attached Figures 1-2 The simulated supergravity slope model test device provided in the present application includes: a friction mechanism, a loading mechanism and a model box 1; the friction mechanism includes a friction belt 5, a friction belt support 7, a rotating shaft 6, a conveyor belt 10, a speed reduction mechanism 11 for controlling the speed of the conveyor belt 10, and a motor 12; the loading mechanism includes a hydraulic device 21, an oil pipe 20, an oil cylinder 18, a piston 17 and a pressure plate 16; the model box 1 is welded from high-strength stainless steel, no baffles are set on the front and rear sides, and the top is open.

[0041] in:

[0042] 1) The slope model 4 is placed in the model box 1. The slope model 4 is made of similar materials with a ratio determined by mechanical tests. The model box 1 is fixed on the base 2 through the support 3, and the support 3 is modified by a jack.

[0043] 2) The friction mechanism is arranged at the rear side of the model box 1, wherein the friction belt 5 is arranged close to the rear side of the slope model 4, and the friction belt 5 is tightened through the rotating shafts 6 at both ends. The rotating shaft 6 is fixed to the wall 8 through the friction belt support 7, and the transmission shaft 9 on the right side of the lower rotating shaft 6 is connected to the speed reduction mechanism 11 through the conveyor belt 10, and the speed reduction mechanism 11 is directly connected to the motor 12, and the lower part of the motor 12 is connected to the bracket 13, and the lower part of the bracket 13 is welded with a gasket 15, and the gasket 15 is fixed to the ground through bolts 14.

[0044] 3) The loading mechanism is arranged at the front side of the box 1, wherein the hydraulic device 21 is connected to the oil cylinder 18 through the oil pipe 20 and is fixed to the base 2 through a plurality of supports 19. The oil cylinder 18 is connected to the pressure plate 16 through the piston 17.

[0045] 4) A tempered glass plate 22, a plastic film 23 and a micro pressure box 24 are arranged from left to right between the pressing plate 16 and the slope model 4 to ensure that the positive pressure of the pressing plate 16 is evenly loaded on the front of the slope model 4. Several micro pressure boxes 24 can record the changes in the pressure on the slope model 4.

[0046] Based on the same inventive concept, the present application also provides a simulated supergravity slope model test method, which is implemented by the simulated supergravity slope model test device, using the vertical downward friction force generated between the downward rotation of the conveyor belt 10 and the slope model 4 to simulate the gravity of the on-site slope, and the specific steps are as follows:

[0047] 1) Determine the physical and geometric parameters of the slope model 4 according to the similarity ratio, determine the mix ratio of similar materials through mechanical tests, and configure similar materials.

[0048] 2) According to the test plan, the slope model 4 is built, and sensors such as displacement and moisture are buried in the slope model 4, and the displacement and moisture content of the slope model 4 under the effects of excavation, rainfall, etc. are subsequently monitored.

[0049] 3) Based on the on-site slope gravity designed in the test and the friction coefficient between the rear side of the slope model 4 and the conveyor belt 10, a loading mechanism is used to apply normal pressure to the front side of the slope model 4.

[0050] 4) Start the motor 12, control the speed reduction mechanism 11 to adjust the rotation speed of the friction belt 5, provide the slope model 4 with a vertical downward friction force to be equivalent to the gravity of the slope on site, and always keep the pressure value of the micro pressure box 24 stable.

[0051] 5) After achieving the Ng gravity acceleration of slope model 4, continue to carry out other working condition tests such as rainfall and excavation of slope model 4.

[0052] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A simulated hypergravity slope model test device, characterized in that: include: Model box, loading mechanism and friction mechanism, among which, The model box is used to load the slope model; the top, front side and rear side of the model box are all set to be open; The loading mechanism is used to apply a horizontal load to the slope model to provide a normal pressure required for friction; The friction mechanism is used to generate a vertical downward friction force on the slope model to simulate the gravity field of the rock slope; The slope model is formed by stacking prefabricated blocks with barite powder, quartz sand and iron powder as aggregates; The loading mechanism is arranged at the front side of the model box, and the loading mechanism comprises: a hydraulic device, an oil cylinder and a pressing plate, The hydraulic device is connected to the oil cylinder via an oil pipe to deliver high-pressure oil to the oil cylinder; The piston rod of the oil cylinder is connected to the pressing plate, and the pressing plate is arranged corresponding to the front side of the model box; the oil cylinder drives the pressing plate to apply horizontal compressive stress to the slope model; Also includes: tempered glass plate and plastic film, The tempered glass plate is movably arranged at the front side of the model box; the pressure plate is fixed on one side of the tempered glass plate, driving the tempered glass plate to move linearly between the front side and the rear side of the model box, so that the tempered glass plate applies horizontal compressive stress to the slope model; The plastic film is arranged between the tempered glass plate and the slope model; It also includes a plurality of micro pressure boxes, which are arranged on the front side of the slope model; the micro pressure boxes are connected to a resistance strain tester to send the normal pressure value applied on the slope model to the resistance strain tester; The friction mechanism is arranged at the rear side of the model box, and comprises: a friction belt, two rotating shafts, a conveyor belt, a speed reduction mechanism and a motor. The friction belt is arranged close to the rear side of the slope model, and the friction belt is tightened by the rotating shafts at both ends; The two rotating shafts are fixed on the wall through the friction belt supports; One of the rotating shafts is connected to the speed reduction mechanism via the conveyor belt; The speed reduction mechanism is connected to the electric motor.

2. The simulated hypergravity slope model test device according to claim 1, characterized in that: The model box is fixed on the base through vertically arranged pillars; the pillars are retractable structures.

3. The simulated hypergravity slope model test device according to claim 1, characterized in that: The right side of the model box is arranged as a semi-closed structure.

4. A method for simulating a high gravity slope model test, characterized in that: The method is realized by the simulated hypergravity slope model test device according to any one of claims 1 to 3, comprising the following steps: Determine the physical property parameters and geometric parameter indicators of the slope model according to the similarity ratio, determine the mix ratio of similar materials through mechanical tests, and configure the similar materials; The slope model of the experimental design is constructed by stacking the similar materials; According to the Ng gravitational acceleration of the slope model designed by the experiment and the friction coefficient between the slope model and the friction mechanism, applying a normal pressure to the front side of the slope model through the loading mechanism; Applying a vertical downward friction force to the slope model through the friction mechanism to simulate the supergravity of the slope model; After the supergravity simulation of the slope model is realized, the rainfall, blasting vibration and excavation test process of the slope model is continued.

5. The simulated hypergravity slope model test method according to claim 4, characterized in that: When the slope model is being piled up, a displacement sensor and a water content sensor are buried in the slope model.

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