CN112177060B - Centrifugal model test device and test method for simulating scouring of wall toe of reinforced retaining wall - Google Patents
Centrifugal model test device and test method for simulating scouring of wall toe of reinforced retaining wall Download PDFInfo
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D33/00—Testing foundations or foundation structures
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B1/00—Equipment or apparatus for, or methods of, general hydraulic engineering, e.g. protection of constructions against ice-strains
- E02B1/02—Hydraulic models
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/02—Retaining or protecting walls
- E02D29/0225—Retaining or protecting walls comprising retention means in the backfill
- E02D29/0241—Retaining or protecting walls comprising retention means in the backfill the retention means being reinforced earth elements
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D31/00—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution
- E02D31/06—Protective arrangements for foundations or foundation structures; Ground foundation measures for protecting the soil or the subsoil water, e.g. preventing or counteracting oil pollution against corrosion by soil or water
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2600/00—Miscellaneous
- E02D2600/10—Miscellaneous comprising sensor means
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Abstract
The invention relates to a centrifugal model test device and a test method for simulating the scouring of the wall toe of a reinforced retaining wall, wherein the test device comprises the following components: a model test chamber; reinforced retaining wall model: the reinforced earth retaining wall is composed of a horizontal base embedded in the foundation soil, a wall surface module paved on the horizontal base layer by layer and a plurality of layers of reinforcing materials which are paved in the filling soil from top to bottom and connected with the wall surface module; a sand suction mechanism; high-speed cameras. Compared with the prior art, the method can be used for researching the stress characteristic evolution of the rib materials under the influence of water flow erosion on the reinforced retaining wall and the deformation and damage process of the retaining wall more economically, conveniently, reliably and intelligently in a laboratory.
Description
Technical Field
The invention belongs to the technical field of geotechnical engineering and geological engineering tests, and relates to a centrifugal model test device and a test method for simulating erosion of the toes of a reinforced retaining wall.
Background
In the last 60 th century, the french engineer Henri Vidal proposed the concept of "reinforced earth", and reinforced earth retaining walls have come into play. Compared with the traditional gravity retaining wall, cantilever retaining wall, counterfort retaining wall and the like, the reinforced retaining wall is rapidly developed by the advantages of low cost, simple construction, attractive appearance, high stability, good earthquake resistance and the like, and is widely applied to engineering construction in the fields of buildings, traffic, water conservancy, national soil resources and the like. The reinforced earth retaining wall is a good flexible structure, and under rivers washout, has the anti deformability of certain degree, but the tolerance ability of reinforced earth retaining wall to rivers erode is limited, and especially when the foundation soil near the wall toe receives the undercutting degree of rivers too big, also can cause the wall body constantly to subside, slide and topple the destruction even, if: the reinforced earth retaining wall of the mountain area near the river and the ditch is influenced by flood, debris flow and the like, foundation soil near the wall toe is largely washed and hollowed, the eccentric load of the retaining wall is continuously increased, the trend that the embankment retaining wall topples towards the river is enhanced, finally embankment damage and road interruption are caused, and great influence is caused on the production life and road transportation safety of people. Therefore, the study on the deformation and damage rule of the reinforced retaining wall under the condition of water flow undercutting has an important guiding function on the design and construction of the reinforced retaining wall project.
The model test can visually reflect the stress and deformation characteristics of the prototype structure, and is popular among students. At present, indoor model tests for reinforced retaining walls mainly comprise 1g reduced-scale model tests and ng centrifugal model tests. Compared with the traditional 1g reduced scale model test, the centrifugal model test has the advantage of keeping the same stress of the model and the prototype, and is widely applied to the stability research of side slope retaining walls and reinforced retaining walls. In the centrifugal model test, because the model box rotates at a high speed in the centrifuge, when the excavation working condition of a side slope or a foundation pit is simulated, the soil body cannot be directly excavated manually like a 1g reduced scale model test, so the excavation simulation in the centrifuge is always a difficult problem for developing the centrifugal test.
At present, methods for simulating soil excavation in centrifugal model tests mainly include the following three types: firstly, soil to be excavated is excavated in advance during sample preparation, and then the reaction of the soil or a soil retaining structure under the condition of stress improvement is researched by increasing centrifugal acceleration; secondly, in a centrifugal model test, the excavation is simulated by discharging liquid with the density similar to that of a soil body; thirdly, excavating and removing the soil in the model by using high-precision mechanical equipment. The first method artificially ignores the influence of the stress path of the centrifugal machine, and cannot truly simulate the stress field of an actual structure and the change caused by excavation; the second method adopts a method of discharging liquid with density similar to that of soil, consumes time and labor, and puts forward a plurality of requirements on sample preparation of a test model; the third type of method is typically cost prohibitive with precision excavation machinery and often requires integration with a precision and sophisticated centrifuge test platform system. In addition, due to the design defects of mechanical devices, the designed devices can only complete excavation simulation of soil bodies above the ground, for example, a new device for simulating slope excavation in the centrifugal model test process developed by Qinghua university can only cut and push away the soil body to be excavated at the toe from the slope through a blade to realize excavation simulation of the soil body at the toe, but cannot realize excavation simulation of foundation soil under the toe, so that the device cannot realize centrifugal test simulation of foundation pit excavation or excavation simulation of foundation soil by water flow.
Disclosure of Invention
The invention aims to provide a centrifugal model test device and a test method for simulating the erosion of the wall toe of a reinforced retaining wall, so as to solve the problem that the existing centrifugal model test device cannot realize the centrifugal test simulation of the undercutting of the foundation soil, and can be used for researching the stress characteristic evolution of a rib material under the influence of the undercutting of water flow on the reinforced retaining wall and the deformation and damage process of the retaining wall more economically, conveniently, reliably and intelligently in a laboratory.
The purpose of the invention can be realized by the following technical scheme:
one of the technical schemes of the invention provides a centrifugal model test device for simulating the scouring of the wall toe of a reinforced retaining wall, which comprises the following steps:
a model test chamber;
placing the reinforced retaining wall model in a model test box: the reinforced earth retaining wall is composed of a horizontal base embedded in the foundation soil, a wall surface module paved on the horizontal base layer by layer and a plurality of layers of reinforcing materials which are paved in the filling soil from top to bottom and connected with the wall surface module;
inhale husky mechanism: the device is arranged on a model test box, and the ground foundation soil on the other side of the reinforced retaining wall is sucked layer by simulating the water flow undercutting phenomenon;
a high-speed camera: the device is arranged beside the model test box and is used for recording the image change in the model test box in the sand suction process.
Furthermore, between two adjacent layers of wall modules, the bottom of the wall module on the upper layer and the top of the wall module on the lower layer are provided with a groove and a protrusion which are matched with each other.
Furthermore, a displacement sensor is arranged at the position of the middle wall surface of the reinforced retaining wall;
and a resistance type strain gauge is also arranged between each layer of the rib material and the reinforced retaining wall.
Furthermore, vaseline is further coated on the inner wall of the model test box, and a transparent plastic film is adhered on the inner wall of the model test box.
Further, inhale husky mechanism include air exhauster, collection husky box, send husky pipeline, removal subassembly and inhale husky mouth, wherein, collection husky box set up at model test roof portion, still be equipped with suction opening and husky box entry on collection husky box, the air exhauster arrange in suction opening position, send husky pipeline to arrange on removing the subassembly to can be driven by removing the subassembly and remove in level and vertical direction, send the one end of husky pipeline to connect husky box entry, the other end is connected inhale husky mouth.
Furthermore, the sand conveying pipeline is formed by splicing a plurality of sections of hard pipes and hoses, wherein the hoses are provided with at least one section along the horizontal moving direction and the vertical moving direction.
Furthermore, the moving assembly comprises a horizontal sliding rail arranged at the top of the model test box, a moving platform arranged on the horizontal sliding rail and capable of moving back and forth along the horizontal sliding rail, and a vertical sliding rail arranged on the moving platform, and the sand conveying pipeline is arranged on the vertical sliding rail and capable of moving back and forth vertically along the vertical sliding rail.
Furthermore, one side of the model test box, which is not in contact with the filling soil, is taken as the front side, an organic glass window is arranged on the front side of the model test box, and the high-speed camera is arranged beside the organic glass window.
Furthermore, the centrifugal model test device also comprises a computer which is respectively connected with the sand suction mechanism and the high-speed camera through data lines.
The second technical scheme of the invention provides a centrifugal model test method for simulating the scouring of the wall toe of the reinforced retaining wall, which is implemented by adopting the centrifugal model test device, and the test method comprises the following steps:
(1) preparing foundation soil in a model test box, embedding a horizontal base in the middle of the foundation soil, then placing a first layer of wall surface module on the horizontal base, then laying filling soil with a height corresponding to the height of the wall surface module and compacting, finally laying a rib material connected with the wall surface module, meanwhile, arranging a resistance type strain gauge at the connecting position of the rib material and the wall surface module, and repeating the steps until the reinforced soil retaining wall is finished;
(2) a sand suction mechanism is arranged on the model test box, meanwhile, a computer is connected with the sand suction mechanism and the high-speed camera by adopting a data line, and the position and shooting parameters of the high-speed camera are adjusted to ensure that the computer can shoot a clear image in the model test box;
(3) placing the model test box on a centrifugal unit, adjusting the acceleration of the centrifugal unit to a set value and stabilizing the centrifugal unit, then controlling a sand suction mechanism to move, and sucking foundation soil on one side of a reinforced retaining wall in a layered mode until the water flow undercutting simulation process is completed, and meanwhile, recording image changes in the model test box in the whole sand suction process by adopting a high-speed camera;
(4) and processing the image recorded by the high-speed camera to obtain the change destruction characteristic and the stability evolution process of the reinforced retaining wall in the process of simulating the water flow undercutting.
Compared with the prior art, the invention has the following advantages:
(1) the device avoids uncontrollable property of simulating scouring by water flow, and realizes removal of foundation soil at the lower part of the reinforced retaining wall toe under the condition that a centrifugal machine does not stop by skillfully utilizing a sand suction method so as to simulate continuous loss of the foundation soil due to erosion of the water flow.
(2) The sand suction device and the model box are mutually independent, the limit of narrow internal idle size of the test model box after sample preparation is avoided, the reliability is high, the cost is low, the sand suction device is easy to mount, dismount and maintain, and the possibility of popularization and application of the sand suction device is improved.
(3) The sand suction device is convenient to control, can better remove the foundation soil of the reinforced retaining wall in real time and for multiple times, and is convenient for simulating that the foundation soil at the lower part of the reinforced retaining wall is continuously strengthened by undermining of water flow.
(4) The sand suction device can be connected with a computer through a data line so as to intelligently remove the foundation soil layer by using programming.
Drawings
FIG. 1 is a schematic view of a test apparatus of the present invention;
FIG. 2 is a schematic view of the position of a sand sucking port;
the notation in the figure is:
1 is the banket, 2 is the muscle material, 3 is the wall module, 4 is foundation soil, 5 is the model test case, 6 is inhaling husky mouth, 7 is the hard tube, 8 is horizontal slide rail, 9 is the hose, 10 is vertical slide rail, 11 is the collection husky box, 12 is the air exhauster, 13 is the data connection line, 14 is computer control equipment.
Detailed Description
The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
In the following embodiments, unless otherwise specified, all the functional components or structures in the art are conventional components or structures for realizing the corresponding functions.
The invention provides a centrifugal model test device for simulating the scouring of the wall toe of a reinforced retaining wall, the structure of which is shown in figure 1 and comprises the following components:
a model test chamber 5;
and (3) placing the reinforced retaining wall model in the model test box 5: the reinforced earth retaining wall comprises foundation soil 4 laid at the bottom of a model test box 5, a reinforced earth retaining wall arranged in the middle of the foundation soil 4 and filling 1 compacted and filled in a cavity enclosed by one side of the reinforced earth retaining wall and the side surface of the model test box 5, wherein the reinforced earth retaining wall consists of a horizontal base buried in the foundation soil 4, a wall surface module 3 laid on the horizontal base layer by layer and a plurality of layers of reinforcement materials 2 which are laid in the filling 1 from top to bottom and connected with the wall surface module 3;
inhale husky mechanism: the device is arranged on a model test box 5, and is used for absorbing and removing foundation soil 4 on the other side of the reinforced retaining wall layer by simulating a water flow undercutting phenomenon;
a high-speed camera: which is arranged beside the model test chamber 5 and is used for recording the image change in the model test chamber 5 during the sand suction process.
In a specific embodiment of the present invention, between two adjacent layers of wall modules 3, the bottom of the wall module 3 on the upper layer and the top of the wall module 3 on the lower layer are provided with grooves and protrusions which are engaged with each other.
In a specific embodiment of the invention, a displacement sensor is further arranged at the middle wall surface of the reinforced retaining wall;
and a resistance type strain gauge is also arranged between each layer of the rib material 2 and the reinforced retaining wall.
In a specific embodiment of the present invention, vaseline is further coated on the inner wall of the model test chamber 5, and a transparent plastic film is adhered thereto.
In a specific embodiment of the invention, the sand suction mechanism comprises an exhaust fan 12, a sand collection box 11, a sand conveying pipeline, a moving assembly and a sand suction port 6, wherein the sand collection box 11 is arranged at the top of the model test box 5, the sand collection box 11 is further provided with an air suction port and a sand box inlet, the exhaust fan 12 is arranged at the air suction port, the sand conveying pipeline is arranged on the moving assembly and can be driven by the moving assembly to move in the horizontal and vertical directions, one end of the sand conveying pipeline is connected with the sand box inlet, and the other end of the sand conveying pipeline is connected with the sand suction port 6.
Furthermore, the sand conveying pipeline is formed by splicing a plurality of sections of hard pipes 7 and hoses 9, wherein the hoses 9 are provided with at least one section along the horizontal moving direction and the vertical moving direction.
Furthermore, the moving assembly comprises a horizontal slide rail 8 arranged at the top of the model test box 5, a moving platform arranged on the horizontal slide rail 8 and capable of moving back and forth along the horizontal slide rail 8, and a vertical slide rail 10 arranged on the moving platform, and the sand conveying pipeline is arranged on the vertical slide rail 10 and capable of moving back and forth vertically along the vertical slide rail.
In a specific embodiment of the invention, the side of the model test box 5 which is not in contact with the filling soil 1 is taken as a front side, the front side of the model test box 5 is provided with an organic glass window, and the high-speed camera is arranged beside the organic glass window.
In a specific embodiment of the present invention, the centrifugal model testing apparatus further includes a computer, which is connected to the sand suction mechanism and the high speed camera through data lines, respectively.
The invention also provides a centrifugal model test method for simulating the scouring of the wall toe of the reinforced retaining wall, which is implemented by adopting the centrifugal model test device, and the test method comprises the following steps:
(1) preparing foundation soil 4 in a model test box 5, embedding a horizontal base in the middle of the foundation soil 4, then placing a first layer of wall surface module 3 on the horizontal base, then laying filling 1 with a height corresponding to the height of the wall surface module 3 and compacting, finally laying a rib 2 connected with the wall surface module 3, meanwhile, arranging a resistance type strain gauge at the connecting position of the rib 2 and the wall surface module 3, and repeating the steps until the reinforced soil retaining wall is finished;
(2) a sand suction mechanism is arranged on the model test box 5, meanwhile, a computer is connected with the sand suction mechanism and the high-speed camera by adopting a data line, and the position and shooting parameters of the high-speed camera are adjusted to ensure that the high-speed camera can shoot a clear image in the model test box 5;
(3) placing a model test box 5 on a centrifugal unit, adjusting the acceleration to a set value and stabilizing, then controlling a sand suction mechanism to move, and sucking foundation soil 4 on one side of a reinforced retaining wall in a layered manner until the water flow undercutting simulation process is completed, and simultaneously recording the image change in the model test box 5 in the whole sand suction process by adopting a high-speed camera;
(4) and processing the image recorded by the high-speed camera to obtain the change destruction characteristic and the stability evolution process of the reinforced retaining wall in the process of simulating the water flow undercutting.
The above embodiments may be implemented individually, or in any combination of two or more.
The above embodiments will be described in more detail with reference to specific examples.
Example 1:
the embodiment provides a centrifugal model test device and a test method for simulating the scouring of the wall toe of a reinforced retaining wall, and the main structure of the centrifugal model test device is shown in fig. 1 and mainly comprises the reinforced retaining wall, a sand suction mechanism and computer control equipment 14. The reinforced retaining wall is built inside a model test box 5 with an opening at the top and consists of filling 1, reinforcing bars 2, wall modules 3 and foundation soil 4; the sand suction equipment is arranged at the top of the model test box 5 and consists of an exhaust fan 12, a sand collecting box 11, a hard pipe 7, a hose 9, a vertical slide rail 10, a horizontal slide rail 8 and a sand suction port 6; the computer control device 14 is connected with the horizontal slide rail 8 and the vertical slide rail 10 by means of a data connection line 13 and the like. The sand sucking port 6 arranged at the end part of the hard pipe 7 can move horizontally and vertically through a sand sucking mechanism controlled by the computer control equipment 14; by utilizing the suction force generated by the exhaust fan 12, the sand suction port 6 can perform layered suction on the foundation soil 4 at the lower part of the reinforced retaining wall so as to simulate the scouring and erosion of water flow on the foundation soil 4; the sucked foundation soil 4 can enter the sand sucking device through the sand sucking port 6, gradually reaches the sand collecting box 11 along the hard pipe 7 and the hose 9, and is stored.
The model test box 5 in this embodiment has an inner wall of 600mm × 400mm × 500mm (length × width × height), an opening at the top end, a steel plate welded to the bottom surface of the box, and a transparent organic glass mounted on the front surface of the box to form an organic glass window.
The wall height of the reinforced retaining wall model in the embodiment is 180mm, the wall elevation angle is 90 degrees, the length of the rib material 22 is 140mm, and the vertical distance of the rib material 2 is 30 mm. The wall modules 3 have dimensions of 50mm x 30mm (length x width x height). The thickness of the foundation soil 4 is 200 mm.
In the embodiment, the rib 2 is made of nylon gray window screen, and a wide-strip tensile test is performed on the rib according to the standard requirements, and the ultimate tensile strength is 2.51kN/m, the tensile strength at 5% elongation is 0.91kN/m, and the rigidity (the ratio of the tensile strength at 5% elongation to the elongation) is 18.2 kN/m.
The wall modules 3 in this embodiment are plain concrete blocks poured by cement mortar, and have grooves at the bottom and protrusions at the top matched with the grooves for simulating shear keys between the actual modular retaining wall modules 3.
The filling 1 and the foundation soil 4 in the embodiment are both constructed yellow sand, and the sand is determined to be medium sand through a particle analysis test. The maximum and minimum dry densities of the yellow sand are 1.65 and 1.44g/cm respectively3. When the model is built, the relative compactness of the foundation and the filling 1 is controlled to be 85 percent and 65 percent respectively, the compactness is controlled to be 97 percent and 95 percent respectively, and the corresponding density is controlled to be 1.62g/cm respectively3And 1.57g/cm3. The internal friction angles of the foundation soil 4 and the filling soil 1 are respectively 42 degrees and 36 degrees through a direct shear test.
The sand suction port 6 in this embodiment is made of polypropylene, and has a size of 400mm × 10mm × 20mm (length × width × height), and the foundation soil 4 can be continuously sucked and removed by the suction force generated by the suction fan 12.
A second part:
the embodiment also provides a test method for simulating the influence of water flow erosion on a reinforced retaining wall in a centrifuge by using a sand absorption method, and the implementation process comprises the following steps:
(1) preparation of test materials and devices
Respectively manufacturing a model test box 5, a rib material 2, a wall surface module 3, filling soil 1 and foundation soil 4 according to the size and the material required by the test, and preparing a sand collecting box 11, a hard pipe 7, a hose 9, a vertical slide rail 10, a horizontal slide rail 8, a sand suction port 6, a data connecting wire 13, a computer control device 14 and an exhaust fan 12 meeting the power requirement.
(2) Model for building reinforced retaining wall
A Polyester (PET) transparent plastic film is adhered to the inner wall of an organic glass window of the model test box 5, vaseline is smeared on the other 3 inner walls of the model box, and a polytetrafluoroethylene film is adhered, so that film-to-film friction is formed between the reinforced retaining wall and the box wall in the test process, and the boundary effect is reduced.
The foundation soil 4 is prepared by adopting a sand rain method, and the density is controlled to be 1.62g/cm3(ii) a Base watch with embedded horizontal base and soft brushCleaning the surface, placing a first layer of wall surface module 3, laying filling 1 with the height corresponding to the module, compacting by a rubber hammer, and controlling the density of the filling 1 to be 1.57g/cm3And finally, paving the rib materials 2, and repeating the steps until the retaining wall is filled.
In addition, 3 differential displacement sensors with the models of YWC-5 and the measuring range of +/-50 mm are arranged along the wall height at the position of the middle wall surface of the reinforced retaining wall so as to test the horizontal displacement of the reinforced retaining wall surface; adhering a resistance type strain gauge with the model BX120-2BB to the connection part of each layer of the rib 2 and the wall surface module 3 to test the connection strain (tension) between the rib 2 and the wall surface module 3; before the strain gauge is adhered, a square thin layer with the side length of 15mm is poured on the surface of the nylon window screen by adopting epoxy resin to serve as a force transmission medium, the strain gauge is adhered on the square thin layer and an electric wire is welded, and then the strain gauge is covered by silicon rubber to be protected from being damaged by sand corners.
(3) Installation and commissioning device
Moving the model test box 5 to a hanging basket of a centrifugal tester (namely a centrifuge) and adjusting the model test box to a proper position, then installing an exhaust fan 12, a sand collecting box 11, a horizontal slide rail 8 and a vertical slide rail 10 at the top of the model test box 5, and connecting the equipment with a sand suction port 6 by using a hard pipe 7 and a hose 9; the computer control equipment 14 is connected with the horizontal slide rail 8 and the vertical slide rail 10 through a data connecting wire 13, and the control parameters of the computer control equipment 14 are adjusted, so that the sand suction port 6 can smoothly move vertically and horizontally; erecting a high-speed camera on the front side of the model test box 5, connecting the high-speed camera with a computer control device 14 through a data connecting line 13 passing through a central rotating shaft of a centrifugal tester, and adjusting the position and parameters of the camera to enable a focal plane of the camera to be parallel to the surface of the model box and a clear image to be shot;
(4) initial test
Starting a centrifugal testing machine, setting the acceleration of a testing model to be increased from 1g to 20g at a constant speed, then keeping the acceleration of 20g until the data curve of each measuring element is stable, then controlling the horizontal and vertical movement of the sand sucking port 6 through the computer control equipment 14, sucking out foundation soil 4 layer by layer until the water flow erosion process shown in the figure 1 is completed, and meanwhile, recording the image change of the box side in the testing process by using a high-speed camera.
(5) Analysis of test results
After the test is finished, analyzing the image recorded by the high-speed camera in the test process through PIV image processing software to obtain a reinforced retaining wall displacement field at different moments, respectively obtaining the displacement of the wall surface module 3 of the reinforced retaining wall and the stress of the reinforced material 2 through the differential displacement sensor and the resistance-type strain gauge, and finally analyzing the deformation damage characteristic and the stability evolution process of the reinforced retaining wall in the water flow erosion process.
The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.
Claims (9)
1. The utility model provides a simulation reinforced earth retaining wall toe receives centrifugal model test device that erodees which characterized in that includes:
a model test chamber;
the reinforced retaining wall model is arranged in the model test box;
inhale husky mechanism: the device is arranged on a model test box, and the ground foundation soil on the other side of the reinforced retaining wall is sucked layer by simulating the water flow undercutting phenomenon;
inhale husky mechanism include air exhauster, collection husky box, send husky pipeline, removal subassembly and inhale husky mouth, wherein, collection husky box set up at model test case top, still be equipped with suction opening and husky box entry on collection husky box, the air exhauster arrange in suction opening position, send husky pipeline to arrange on the removal subassembly to can be driven by the removal subassembly and remove in level and vertical direction, send the one end of husky pipeline to connect husky box entry, the other end is connected inhale husky mouth.
2. The centrifugal model test device for simulating the toe erosion of the reinforced retaining wall according to claim 1, wherein the reinforced retaining wall model comprises foundation soil laid at the bottom of the model test box, a reinforced retaining wall arranged in the middle of the foundation soil, and filling soil filled in a cavity enclosed by one side of the reinforced retaining wall and the side surface of the model test box in a compacting manner, and the reinforced retaining wall comprises a horizontal base buried in the foundation soil, a wall surface module laid on the horizontal base layer by layer, and a plurality of layers of ribs which are laid in the filling soil from top to bottom and connected with the wall surface module.
3. The centrifugal model test device for simulating the toe erosion of the reinforced retaining wall according to claim 2, wherein between two adjacent layers of wall modules, the bottom of the wall module on the upper layer and the top of the wall module on the lower layer are provided with grooves and protrusions which are matched with each other;
a displacement sensor is also arranged at the middle wall surface of the reinforced retaining wall;
and a resistance type strain gauge is also arranged between each layer of the rib material and the reinforced retaining wall.
4. The centrifugal model test device for simulating the scouring of the toes of a reinforced retaining wall as claimed in claim 1, wherein vaseline is further coated on the inner wall of the model test box, and a transparent plastic film is adhered on the inner wall of the model test box.
5. The centrifugal model test device for simulating the scouring of the toes of a reinforced retaining wall as claimed in claim 1, wherein the sand conveying pipeline is formed by splicing a plurality of sections of hard pipes and hoses, and the hoses are provided with at least one section in both the horizontal moving direction and the vertical moving direction.
6. The centrifugal model test device for simulating the scouring of the toes of a reinforced retaining wall as claimed in claim 1, wherein the moving assembly comprises a horizontal slide rail arranged at the top of the model test box, a moving platform arranged on the horizontal slide rail and capable of moving back and forth along the horizontal slide rail, and a vertical slide rail arranged on the moving platform, and the sand conveying pipeline is arranged on the vertical slide rail and capable of moving back and forth along the vertical slide rail.
7. The centrifugal model test device for simulating the scouring of the toes of a reinforced retaining wall as claimed in claim 1, further comprising a high-speed camera disposed beside the model test chamber and used for recording the image change in the model test chamber during the sand suction process;
the method is characterized in that one side, which is not in contact with filling soil, of the model test box is taken as the front side, an organic glass window is arranged on the front side of the model test box, and the high-speed camera is relatively and fixedly arranged beside the organic glass window.
8. The centrifugal model test device for simulating the scouring of the toes of a reinforced retaining wall as claimed in claim 7, further comprising a computer which is connected with the sand suction mechanism and the high speed camera respectively.
9. A centrifugal model test method for simulating the scouring of the wall toe of a reinforced retaining wall, which is implemented by adopting the centrifugal model test device as claimed in any one of claims 1 to 8, and is characterized by comprising the following steps:
(1) preparing foundation soil in a model test box, embedding a horizontal base in the middle of the foundation soil, then placing a first layer of wall surface module on the horizontal base, then laying filling soil with a height corresponding to the height of the wall surface module and compacting, finally laying a rib material connected with the wall surface module, meanwhile, arranging a resistance type strain gauge at the connecting position of the rib material and the wall surface module, and repeating the steps until the reinforced soil retaining wall is finished;
(2) a sand suction mechanism is arranged on the model test box, meanwhile, a computer is connected with the sand suction mechanism and the high-speed camera, and the position and shooting parameters of the high-speed camera are adjusted to ensure that the computer can shoot a clear image in the model test box;
(3) placing the model test box on a centrifuge, adjusting the acceleration of the centrifuge to a set value and stabilizing the model test box, then controlling a sand suction mechanism to move, and sucking foundation soil on one side of a reinforced retaining wall in a layered mode until the water flow undercutting simulation process is completed, and meanwhile, recording image changes in the model test box in the whole sand suction process by using a high-speed camera;
(4) and processing the image recorded by the high-speed camera to obtain the change destruction characteristic and the stability evolution process of the reinforced retaining wall in the process of simulating the water flow undercutting.
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