Zero-friction high earth and rockfill dam core wall gravel-doped clay tensile-shear fracture test device

Abstract

The invention relates to a zero-friction high earth and rockfill dam core wall gravel-doped clay tensile-shear fracture test device which comprises a compaction fracture mold and a hollow test groove, the compaction fracture mold is used for manufacturing a gravel-doped clay sample and comprises a test bearing part, a rectangular ring wall and a Z-shaped compaction plate, and the test bearing part is used for bearing the test bearing part. A rectangular groove is formed in the center of the top of the hollow test groove. Through the design of the floating cavity, the air bag set and the buoyancy principle are ingeniously utilized, the test part of the compaction fracture mold is separated from the working platform, the friction between the mold and the platform is fundamentally solved, and the test means of the fracture characteristics of gravel-doped clay are greatly enriched; the device is simple in structure and convenient to operate, a test part of the compaction fracture mold is conveniently leveled, the operation is simple and convenient, the detection precision can be obviously improved, the tensile fracture and shear fracture characteristics are simultaneously measured, and the accurate tensile fracture characteristics and shear fracture characteristics of the gravel-doped clay sample of the high earth and rockfill dam are analyzed.

Description

Technical Field

[0001] The invention relates to the field of geotechnical tests, in particular to a tensile and shear fracture test device for gravel-mixed clay in the core wall of a high earth-rock dam, in particular to a zero-friction tensile-shear fracture test device for gravel-mixed clay in the core wall of a high earth-rock dam. Background Art

[0002] In the planning and construction of high dams, earth-rock dams account for an increasingly high proportion due to their good foundation adaptability and economical construction materials. my country has the largest number of earth-rock high core wall rockfill dams, and most of them are concentrated in the southwest of China. According to statistics, the core wall dams in service in my country with a height of more than 100.0m include Shiziping (136.0m), Xiaolangdi (160.0m), Pubugou (186.0m), Nuozadu (261.5m) and Lianghekou (295.0m). The 300m-class core wall dams under construction and planned include Rumei (315.0m), Gushui (305.0m), Rimen (346.0m) and Qizong (356.0m).

[0003] Traditional low-medium earth-rock dams often use compacted pure clay core walls as an anti-seepage system. However, with the increase in construction height, the disadvantage of poor compressive performance of clay has gradually become prominent. The uneven settlement of the core wall and the rockfill body will cause cracks in the core wall clay. High earth-rock dams often add gravel into the core wall to improve the compressive performance of the anti-seepage core wall and reduce uneven settlement. The essence of core wall cracks is shear failure, tension failure or shear-tension composite failure caused by the stress and strain of the soil exceeding its tensile strength or shear strength. At present, there are few results related to the fracture characteristics of gravel-mixed clay in the core wall. Therefore, it is of great engineering significance and practical value to study the fracture characteristics of gravel-mixed clay and explore the evolution law of gravel-mixed clay cracks.

[0004] At present, soil fracture test devices are mostly focused on studying the fracture characteristics of clay or sand. There is still no test device that can be used to study the fracture characteristics of gravel-mixed clay in the core wall of high earth-rock dams, and it is impossible to measure the tensile fracture and shear fracture characteristics of gravel-mixed clay. In addition, how to eliminate the friction between the mold and the chassis has always been a key issue that needs to be solved in the research and development of geotechnical test devices. Therefore, it is necessary to develop a test device that can measure both tensile fracture characteristics and shear fracture characteristics for gravel-mixed clay in the core wall of high earth-rock dams in the southwest region, so as to make up for the vacancy of the existing gravel-mixed clay fracture characteristics test device and eliminate friction as much as possible. Summary of the invention

[0005] The main problem solved by the present invention is the shortcomings of the existing gravel-mixed clay test technology. A zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device is provided, which can measure both the tensile fracture characteristics of the gravel-mixed clay and the shear fracture characteristics of the gravel-mixed clay, and has significantly enhanced functionality and practicality. One machine has multiple uses, and the cost required for purchasing test equipment is reduced. In addition, the device fundamentally solves the friction between the mold and the floor through the buoyancy principle, greatly enriches the test methods for the fracture characteristics of the gravel-mixed clay, and improves the detection accuracy.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A zero-friction high earth-rock core wall gravel-mixed clay tensile-shear fracture test device comprises a compaction fracture mold and a hollow test trough, wherein the compaction fracture mold is used to make gravel-mixed clay soil samples, and comprises a test bearing part, a rectangular annular wall and a Z-shaped compaction plate, and a rectangular groove is opened at the center of the top of the hollow test trough, and the groove is filled with water that can float the test bearing part loaded with the gravel-mixed clay soil sample;

[0008] The prepared gravel-mixed clay soil sample has a soil sample fracture section, and two sides of the fracture section are respectively arranged as a soil sample front end and a soil sample rear end;

[0009] The test bearing part comprises a front half of the mold, a rear half of the mold, a front floating cavity, a rear floating cavity and a cavity connecting plate, wherein the front half of the mold and the rear half of the mold are detachably mounted on the front floating cavity and the rear floating cavity respectively, and the front floating cavity and the rear floating cavity are detachably connected via the cavity connecting plate;

[0010] The combined structure of the front half of the mold and the front floating cavity is the same as the combined structure of the rear half of the mold and the rear floating cavity, and the two combined structures are centrally symmetrically distributed. The bottoms of the front floating cavity and the rear floating cavity are open and embedded with airbag groups, which are used to adjust the buoyancy of the front floating cavity and the rear floating cavity and their floating angles on the water surface. The front half of the mold and the front floating cavity are both provided with horizontal bubbles, which are used to detect the horizontality of the test bearing part loaded with gravel-mixed clay soil samples.

[0011] The left and right sides of the hollow test trough are respectively provided with a left propeller and a right propeller which are symmetrically distributed in the center, and the left propeller and the right propeller respectively push the front half of the mold and the rear half of the mold toward the center of the test device, so as to apply shear force to the gravel-mixed clay soil sample; the front and rear sides of the hollow test trough are respectively provided with a front puller and a rear puller which are axially symmetrically distributed, and the front puller and the rear puller respectively pull the front half of the mold and the rear half of the mold toward the front and rear sides of the test device, so as to apply tensile force to the gravel-mixed clay soil sample.

[0012] Preferably, the front half of the mold and the rear half of the mold both include a carrying box composed of a lateral push plate, an axial pull plate and a fixed bottom plate, and the lateral push plate and the axial pull plate are respectively vertically fixed on the adjacent side walls of the fixed bottom plate, and the middle parts of the lateral push plate and the axial pull plate are respectively provided with lateral connection holes and axial connection holes, and the first and second seam-making plates are respectively provided with axially symmetrically distributed first and second seam-making plates at both ends of a side of the fixed bottom plate away from the axial pull plate, which are used to pre-make seams on the left and right sides of the soil sample, and the first and second seam-making plates are both detachably mounted on the fixed bottom plate;

[0013] Both ends of one side of the fixed base plate are provided with recesses, and the first seam-making plate and the second seam-making plate are respectively embedded in the recesses on both sides, and the thickness of the first seam-making plate and the second seam-making plate matches the depth of the recesses. A gap is reserved between the first seam-making plate and the second seam-making plate on the same fixed base plate, and the two corresponding groups of first seam-making plates and second seam-making plates on the front and rear fixed base plates fit together.

[0014] Preferably, the Z-shaped pressing plate is made of aluminum alloy, and a press plate gap is provided on both sides thereof, and the press plate gap is adapted to the shape of the two sets of first seam-making plates and second seam-making plates corresponding to the front and rear fixed bottom plates after being bonded to each other;

[0015] The Z-shaped compacting plate is adapted to the shapes of the front half of the mold and the rear half of the mold;

[0016] A pressing plate end handle is arranged on the top of the Z-shaped pressing plate.

[0017] Preferably, the first seam-making plate and the second seam-making plate are both provided with positioning blocks and combination blocks, wherein the combination blocks are located on the lower side of the first seam-making plate and the second seam-making plate, and are connected and combined with the fixed bottom plate by bolts;

[0018] The positioning block is located in the middle of the side of the first seam-making plate and the second seam-making plate, and has a hook hole running through its surface;

[0019] The rectangular ring wall adopts a rectangular annular aluminum alloy ring body, and positioning grooves are opened on the bottom of both sides, and the positioning grooves are matched with the structure of the two sets of first seam plates and second seam plates corresponding to the front and rear fixed bottom plates. The inside of the rectangular ring wall is in contact with the outside of the test load-bearing part, and after being sleeved on the outside of the test load-bearing part, its top is flush with the test load-bearing part.

[0020] Preferably, first threaded holes are provided on the three side surfaces of the fixed bottom plate, and protrusions matching the three groups of first threaded holes are provided on the tops of the front floating cavity and the rear floating cavity, and the carrying box is clamped on the inner sides of the three groups of protrusions and fixedly connected with the front floating cavity or the rear floating cavity by bolts;

[0021] Second threaded holes are provided at both ends of one side opposite to the front floating cavity and the rear floating cavity, and the front floating cavity and the rear floating cavity are fixedly connected by a cavity connecting plate and bolts.

[0022] Preferably, the airbag group includes a plurality of airbag bodies distributed in a rectangular array, made of rubber material, and filled with hydrogen;

[0023] A diaphragm is arranged between the multiple airbags, and a channel is arranged on the diaphragm, and an electromagnetic valve is embedded in the channel. Each airbag is provided with an independent inflation and deflation hole, so that the multiple airbags can be inflated and deflated synchronously or the gas volume in the airbags in the local area can be adjusted.

[0024] Preferably, the outer wall of the hollow test tank is provided with a water inlet hole and a water outlet hole penetrating the groove, and the water inlet hole and the water outlet hole are respectively used to supplement and replace the water in the groove.

[0025] Preferably, the left-side propeller, the right-side propeller, the front-side retractor and the rear-side retractor are installed on the hollow test tank through a lifting mechanism;

[0026] The left thruster includes a left connecting portion and a left control portion for connecting and controlling the extension and retraction of the output end of the left connecting portion;

[0027] The right thruster includes a right connecting portion and a right control portion for connecting and controlling the extension and retraction of an output end of the right connecting portion;

[0028] The front retractor includes a front connecting portion and a front controlling portion for connecting and controlling the extension and retraction of an output end of the front connecting portion;

[0029] The rear retractor includes a rear connecting portion and a rear controlling portion for connecting and controlling the extension and retraction of an output end of the rear connecting portion;

[0030] The output ends of the left connecting part and the right connecting part are respectively connected to the lateral connecting holes on the two carrying boxes;

[0031] The output ends of the front connecting portion and the rear connecting portion are respectively connected to the axial connecting holes on the two carrying boxes.

[0032] Preferably, the left connecting part, the right connecting part, the front connecting part and the rear connecting part are all configured as telescopic driving mechanisms, which adopt at least one of a cylinder, an electric push rod, a hydraulic cylinder and a linear module.

[0033] Preferably, the connection ends of the left connection part, the right connection part, the front connection part and the rear connection part are provided with displacement sensors and stress sensors, which are respectively used to sense the displacement and stress value of the left connection part, the right connection part, the front connection part and the rear connection part during telescopic operation.

[0034] The present invention has the following beneficial effects:

[0035] 1. Through the design of the floating cavity, the airbag group and the buoyancy principle are cleverly used to separate the compaction fracture mold test part from the working platform, fundamentally solving the friction between the mold and the platform, greatly enriching the test methods of gravel-mixed clay fracture characteristics. The design of multiple airbags in the airbag group is convenient for leveling the test part of the compaction fracture mold. The operation is simple and convenient, which can significantly improve the detection accuracy and accurately analyze the tensile fracture characteristics and shear fracture characteristics of gravel-mixed clay soil samples in high earth-rock dams;

[0036] 2. By setting up a combined compaction fracture mold, it can not only be used to make gravel-mixed clay soil samples, but its test bearing part, as the test part of the compaction fracture mold, works with the hollow test trough to measure both the tensile fracture characteristics of gravel-mixed clay and the shear fracture characteristics of gravel-mixed clay. This fills the gap in the existing gravel-mixed clay fracture test device, significantly enhances the functionality and practicality of the device, and reduces the cost required to purchase test equipment.

[0037] 3. By changing the direction and method of applying force to the test part of the compaction fracture mold through the pushers on both sides and the front and rear pullers, the rates of tensile fracture and shear fracture of gravel-mixed clay samples are controlled, providing convenience for studying the influence of different loading rates on the tensile fracture and shear fracture of gravel-mixed clay. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the overall structure of the tensile-shear fracture test device provided by the present invention (the cavity connecting plate, rectangular annular wall and Z-shaped compaction plate are omitted).

[0039] Figure 2 It is a schematic diagram of the overall structure of the compaction and fracture mold in the present invention.

[0040] Figure 3 It is a schematic diagram of the structure of the test bearing part (with the cavity connecting plate omitted) in the present invention.

[0041] Figure 4 For the present invention Figure 3 Exploded view of the structure shown.

[0042] Figure 5 This is a diagram showing the distribution structure of the airbag group in the present invention and the changes during its inflation process.

[0043] Figure 6 It is a schematic diagram of the structure of the gravel-mixed clay soil sample in the present invention.

[0044] Figure 7It is a schematic diagram of the connection structure of the left propeller, the right propeller, the front retractor, the rear retractor and the hollow test tank in the present invention.

[0045] Figure 8 It is a schematic diagram of the test process of the zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device of the present invention.

[0046] In the figure:

[0047] 1. Compact and fracture the mold;

[0048] 1-1, front half of the mold; 1-2, back half of the mold;

[0049] 1-1-1, first seam-making plate; 1-1-2, second seam-making plate; 1-1-3, positioning block; 1-1-4, assembly block; 1-1-5, lateral push plate; 1-1-6, axial pull plate; 1-1-7, fixed bottom plate; 1-1-8, axial connecting hole; 1-1-9, first threaded hole; 1-2-0, lateral connecting hole;

[0050] 1-3, front floating cavity; 1-4, rear floating cavity;

[0051] 1-3-1, second threaded hole; 1-3-2, horizontal bubble; 1-3-3, raised portion; 1-3-4, airbag assembly;

[0052] 1-5, cavity connecting plate; 1-6, rectangular ring wall;

[0053] 1-7, Z-shaped compacting plate; 1-7-1, gap in the middle of the compacting plate; 1-7-2, handle at the end of the compacting plate;

[0054] 2. Gravel-mixed clay soil sample; 2-1. Fracture section of soil sample; 2-2. Front end of soil sample; 2-3. Back end of soil sample;

[0055] 3. Left thruster; 3-1. Left connection part; 3-2. Left control part;

[0056] 4. Right thruster; 4-1. Right connecting part; 4-2. Right control part;

[0057] 5. Front retractor; 5-1. Front connection part; 5-2. Front control part;

[0058] 6. Rear retractor; 6-1. Rear connecting part; 6-2. Rear control part;

[0059] 7. Hollow test tank; 7-1. Water inlet hole; 7-2. Water outlet hole. DETAILED DESCRIPTION

[0060] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific preferred embodiments.

[0061] In the description of the present invention, it should be understood that the terms "left side", "right side", "upper part", "lower part" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. "First", "second" and the like do not indicate the importance of the components, and therefore cannot be understood as limiting the present invention. The specific dimensions used in this embodiment are only for illustrating the technical solution, and do not limit the scope of protection of the present invention.

[0062] like Figure 1-7 As shown, a zero-friction high earth-rockfill dam core wall gravel-mixed clay tensile-shear fracture test device comprises a compaction fracture mold 1 and a hollow test trough 7, wherein the compaction fracture mold 1 is used to make gravel-mixed clay soil sample 2, and comprises a test bearing part, a rectangular annular wall 1-6 and a Z-shaped compaction plate 1-7. The compaction fracture mold 1 is a centrally symmetrical mold with a rectangular cross-section, which can be used to compact the gravel-mixed clay soil sample 2, and can also be used to perform tensile fracture and shear fracture tests on the gravel-mixed clay soil sample 2. The test bearing part, i.e., the test part of the compaction fracture mold, is the part after the compaction fracture mold 1 is disassembled after the rectangular annular wall 1-6 and the Z-shaped compaction plate 1-7 are prepared. A rectangular groove is provided at the center of the top of the hollow test trough 7. The hollow test trough 7 is made of stainless steel, and the inner wall of the groove is coated with a waterproof coating. The groove is filled with water that can float the test bearing part loaded with the gravel-mixed clay soil sample 2;

[0063] The prepared gravel-mixed clay soil sample 2 has a soil sample fracture section 2-1, and the two sides thereof are respectively set as the soil sample front end 2-2 and the soil sample rear end 2-3. The gravel-mixed clay soil sample 2 prepared by the present invention is a central symmetrical structure, which is consistent with the cross-sectional shape of the Z-shaped compaction plate 1-7, and the size is adapted to the inner cavity of the test bearing part. The soil sample fracture section 2-1 is the position where the crack is generated during the actual tensile fracture or shear fracture;

[0064] The test bearing part includes a front half of the mold 1-1, a rear half of the mold 1-2, a front floating cavity 1-3, a rear floating cavity 1-4 and a cavity connecting plate 1-5, wherein the front half of the mold 1-1 and the rear half of the mold 1-2 are detachably mounted on the front floating cavity 1-3 and the rear floating cavity 1-4, respectively, and the front floating cavity 1-3 and the rear floating cavity 1-4 are detachably connected through the cavity connecting plate 1-5, the front half of the mold 1-1 and the rear half of the mold 1-2 are the front half and the rear half of the mold, respectively, and are correspondingly arranged at the front end and the rear end of the gravel-mixed clay soil sample 2, and can respectively realize axial pulling and lateral pushing of the front end 2-2 and the rear end 2-3; During the process of preparing the gravel-mixed clay soil sample 2 and transferring it to the hollow test tank 7, the front floating cavity 1-3 and the rear floating cavity 1-4 are connected by the cavity connecting plate 1-5 to form a horizontal and firm integral plate structure; before the test, the cavity connecting plate 1-5 is removed, so that the front floating cavity 1-3 and the rear floating cavity 1-4 can move relative to the front half 1-1 and the rear half 1-2 of the mold; in the working state, they are fixedly connected to the front half 1-1 and the rear half 1-2 of the mold, respectively, so that the front half 1-1 and the rear half 1-2 of the mold can stably float on the water;

[0065] The test bearing part cooperates with the rectangular ring wall 1-6 and the Z-shaped compaction plate 1-7 to compact the gravel-mixed clay material of the core wall of the high earth-rock dam to form the gravel-mixed clay soil sample 2. After the sample preparation is completed, the rectangular ring wall 1-6 and the Z-shaped compaction plate 1-7 are removed. At this time, the gravel-mixed clay soil sample 2 is loaded in the test bearing part;

[0066] The test bearing part is made of aluminum alloy, which has the advantages of high strength and low density, and can reduce the influence of deadweight on the test as much as possible. It is convenient to measure the fracture characteristics of gravel-mixed clay during the stretching or shearing process of gravel-mixed clay sample 2.

[0067] The combined structure of the front half 1-1 of the mold and the front floating cavity 1-3 is the same as the combined structure of the rear half 1-2 of the mold and the rear floating cavity 1-4, and the two combined structures are centrally symmetrically distributed. The front floating cavity 1-3 and the rear floating cavity 1-4 are open at the bottom and are embedded with an air bag group 1-3-4 for adjusting the buoyancy of the front floating cavity 1-3 and the rear floating cavity 1-4 and their floating angles on the water surface. The front half 1-1 of the mold and the front floating cavity 1-3 are both provided with a horizontal bubble 1-3-2 for detecting Measure the horizontality of the test bearing part loaded with the gravel-mixed clay soil sample 2; in this embodiment, the number of the horizontal bubbles 1-3-2 is set to four, which are respectively set at the four corners of the combined structure of the front floating cavity 1-3 and the rear floating cavity 1-4. Before the test, the state of the horizontal bubbles 1-3-2 is observed to determine whether the test bearing part loaded with the gravel-mixed clay soil sample 2 is horizontal. When the horizontality is poor, the buoyancy and initial angle of the test bearing part loaded with the gravel-mixed clay soil sample 2 are adjusted by inflating the airbag group as a whole or partially;

[0068] The left and right sides of the hollow test tank 7 are respectively provided with a left propeller 3 and a right propeller 4 which are symmetrically distributed in the center. The left propeller 3 and the right propeller 4 respectively push the front half 1-1 of the mold and the rear half 1-2 of the mold toward the center of the test device, so as to apply shear force to the gravel-mixed clay soil sample 2; the front and rear sides of the hollow test tank 7 are respectively provided with a front puller 5 and a rear puller 6 which are axially symmetrically distributed. The front puller 5 and the rear puller 6 respectively pull the front half 1-1 of the mold and the rear half 1-2 of the mold toward the front and rear sides of the test device, so as to apply tensile force to the gravel-mixed clay soil sample 2.

[0069] Further, in the above technical solution, the front half 1-1 of the mold and the rear half 1-2 of the mold both include a carrying box composed of a lateral push plate 1-1-5, an axial pull plate 1-1-6 and a fixed bottom plate 1-1-7, and the lateral push plate 1-1-5 and the axial pull plate 1-1-6 are respectively vertically fixed on the adjacent side walls of the fixed bottom plate 1-1-7, and the middle parts of the lateral push plate 1-1-5 and the axial pull plate 1-1-6 are respectively provided with lateral connecting holes 1-2-0 and axial connecting holes 1-1-8, and the fixed bottom plate 1-1-7 is provided with a first seam-making plate 1-1-1 and a second seam-making plate 1-1-2 which are axially symmetrically distributed at both ends of a side away from the axial pull plate 1-1-6, which are used for pre-fabricating seams on the left and right sides of the soil sample, and the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 are both detachably mounted on the fixed bottom plate 1-1-7;

[0070] Recesses are provided at both ends of one side of the fixed base plate 1-1-7, and the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 are respectively embedded in the recesses on both sides, and the thickness of the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 coincide with the depth of the recesses. A gap is reserved between the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 on the same fixed base plate 1-1-7, and the corresponding two groups of first seam-making plates 1-1-1 and second seam-making plates 1-1-2 on the front and rear fixed base plates 1-1-7 fit together.

[0071] In this embodiment, the thickness of the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 is 0.3 mm, that is, when the two corresponding groups of first seam-making plates 1-1-1 and second seam-making plates 1-1-2 on the front and rear fixed base plates 1-1-7 are attached to each other, the thickness of the prefabricated seams is 0.6 mm.

[0072] Furthermore, in the above technical solution, the Z-shaped pressing plate 1-7 is made of aluminum alloy, and a press plate gap 1-7-1 is provided on both sides thereof, and the press plate gap 1-7-1 is adapted to the shape of the two groups of first seam-making plates 1-1-1 and second seam-making plates 1-1-2 corresponding to the front and rear fixed bottom plates 1-1-7 after being bonded to each other;

[0073] The Z-shaped compacting plate 1-7 is adapted to the shapes of the front half 1-1 of the mold and the rear half 1-2 of the mold so that it can be just inserted into the front half 1-1 of the mold and the rear half 1-2 of the mold;

[0074] A pressing plate end handle 1-7-2 is provided on the top of the Z-shaped pressing plate 1-7, so as to facilitate the removal of the Z-shaped pressing plate 1-7 after the gravel-mixed clay soil sample 2 is compacted.

[0075] Furthermore, in the above technical solution, the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 are both provided with positioning blocks 1-1-3 and combination blocks 1-1-4, wherein the combination blocks 1-1-4 are located on the lower side of the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2, and are connected and combined with the fixed bottom plate 1-1-7 by bolts; the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 are selected to be removed according to the progress of the test. When making gravel-mixed clay soil sample 2 and conducting tensile fracture test, it is not necessary to remove the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2, and when conducting shear fracture test, it is necessary to remove the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2.

[0076] The positioning block 1-1-3 is located in the middle of the side of the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2, and has a hook hole on its surface; when the shear fracture test is carried out, the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 need to be removed, and the combination block 1-1-4 is disconnected from the bearing box, and is used to act as a pulling point in the lateral direction to be pulled out from the gravel-mixed clay soil sample 2. The hook hole set on the positioning block 1-1-3 can be hooked by a hook clamp, and it can be pulled out.

[0077] The rectangular ring wall 1-6 adopts a rectangular annular aluminum alloy ring body, and positioning grooves are opened on the bottom of both sides, and the positioning grooves match the structure of the two groups of first seam-making plates 1-1-1 and second seam-making plates 1-1-2 corresponding to the front and rear fixed bottom plates 1-1-7. The inside of the rectangular ring wall 1-6 fits with the outside of the test bearing part, and after being sleeved on the outside of the test bearing part, its top is flush with the test bearing part.

[0078] Further, in the above technical solution, first threaded holes 1-1-9 are provided on the three side surfaces of the fixed bottom plate 1-1-7, and raised portions 1-3-3 matching the three groups of first threaded holes 1-1-9 are provided on the tops of the front floating cavity 1-3 and the rear floating cavity 1-4, the carrying box is clamped on the inner sides of the three groups of raised portions 1-3-3, and is fixedly connected with the front floating cavity 1-3 or the rear floating cavity 1-4 by bolts, and the bolts penetrate the raised portions 1-3-3 and are screwed into the first threaded holes 1-1-9;

[0079] Second threaded holes 1-3-1 are provided at both ends of the opposite sides of the front floating cavity 1-3 and the rear floating cavity 1-4. The front floating cavity 1-3 and the rear floating cavity 1-4 are fixedly connected by a cavity connecting plate 1-5 and bolts. The cavity connecting plate 1-5 is an aluminum alloy connecting plate with holes. When connecting the front floating cavity 1-3 and the rear floating cavity 1-4, the bolts penetrate the cavity connecting plate 1-5 and enter the second threaded holes 1-3-1.

[0080] Furthermore, in the above technical solution, the airbag group 1-3-4 includes a plurality of airbags distributed in a rectangular array, made of rubber material, and filled with hydrogen to ensure that the front floating cavity 1-3 and the rear floating cavity 1-4 float on the water surface;

[0081] A diaphragm is arranged between the multiple airbags, and a channel is arranged on the diaphragm, and a solenoid valve is embedded in the channel. Each airbag is provided with an independent inflation and deflation hole, so that the multiple airbags can be inflated and deflated synchronously or the gas volume in the airbags in a local area can be adjusted, such as Figure 5 As shown in (a), when not inflated, the lower surfaces of the multiple airbags are flush with the lower edges of the front floating cavity 1-3 and the rear floating cavity 1-4; Figure 5 As shown in (b), when inflated, the surface of the airbag will bulge; Figure 5 As shown in (c), in addition to uniform inflation, the gas in a single air bag in the air bag group 1-3-4 at the bottom of the front floating cavity 1-3 and the rear floating cavity 1-4 can be adjusted, thereby adjusting the floating angle of the front floating cavity 1-3 and the rear floating cavity 1-4 on the water surface so that the two float horizontally on the water surface.

[0082] Furthermore, in the above technical solution, the outer wall of the hollow test tank 7 is provided with a water inlet hole 7-1 and a water outlet hole 7-2 penetrating the groove, and the water inlet hole 7-1 and the water outlet hole 7-2 are respectively used to replenish and replace the water in the groove.

[0083] Further, in the above technical solution, the left propeller 3, the right propeller 4, the front retractor 5 and the rear retractor 6 are installed on the hollow test tank 7 through a lifting mechanism;

[0084] The left thruster 3 includes a left connecting portion 3-1 and a left control portion 3-2 for connecting and controlling the extension and retraction of the output end of the left connecting portion 3-1;

[0085] The right thruster 4 includes a right connecting portion 4-1 and a right control portion 4-2 for connecting and controlling the extension and retraction of the output end of the right connecting portion 4-1;

[0086] The front retractor 5 includes a front connecting portion 5-1 and a front controlling portion 5-2 for connecting and controlling the extension and retraction of the output end of the front connecting portion 5-1;

[0087] The rear retractor 6 includes a rear connecting portion 6-1 and a rear controlling portion 6-2 for connecting and controlling the extension and retraction of the output end of the rear connecting portion 6-1;

[0088] The output ends of the left connecting portion 3-1 and the right connecting portion 4-1 are respectively connected to the lateral connecting holes 1-2-0 on the two carrying boxes;

[0089] The output ends of the front connecting portion 5-1 and the rear connecting portion 6-1 are respectively connected to the axial connecting holes 1-1-8 on the two carrying boxes.

[0090] Based on the above structure, the heights of the left connecting part 3-1 and the right connecting part 4-1 as well as the front connecting part 5-1 and the rear connecting part 6-1 can be controlled to facilitate docking between devices; and pushing or pulling force can be applied to the two carrying boxes respectively.

[0091] Furthermore, in the above technical solution, the left connecting part 3-1, the right connecting part 4-1, the front connecting part 5-1 and the rear connecting part 6-1 are all configured as telescopic driving mechanisms, which use at least one of a cylinder, an electric push rod, a hydraulic cylinder and a linear module.

[0092] Furthermore, in the above technical solution, the connection ends of the left connection part 3-1, the right connection part 4-1, the front connection part 5-1 and the rear connection part 6-1 are all provided with displacement sensors and stress sensors, which are respectively used to sense the displacement and stress value of the left connection part 3-1, the right connection part 4-1, the front connection part 5-1 and the rear connection part 6-1 during telescopic operation. Specifically, the collected data include the displacement from left to right and the thrust received by the left connection part 3-1, and the displacement from right to left and the thrust received by the right connection part 4-1 when the gravel-mixed clay soil sample 2 is sheared and broken; and the displacement from back to front and the tension received by the front connection part 5-1, and the displacement from front to back and the tension received by the rear connection part 6-1 when the gravel-mixed clay soil sample 2 is stretched and broken.

[0093] The zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device provided by the present invention is used in accordance with Figure 8 As shown, where:

[0094] Figure 8 (a) shows the state after the front half 1-1 of the mold and the rear half 1-2 of the mold are spliced;

[0095] Figure 8 (b) shows the Figure 8 (a), the state of assembling the compaction fracture mold 1;

[0096] Figure 8 (c) shows the Figure 8 (b), preparing and compacting gravel-mixed clay soil sample 2;

[0097] Figure 8 (d) shows the Figure 8 (c), the compaction fracture mold 1 is transferred to the state in the groove of the hollow test tank 7;

[0098] Figure 8 (e) shows the Figure 8 (d) Based on the state where the Z-shaped compacting plate 1-7 and the rectangular ring wall 1-6 are removed;

[0099] Figure 8 (f) shows the Figure 8 (e) Based on the above, the test load-bearing part (compression fracture mold test part) is suspended;

[0100] Figure 8 (g) shows the Figure 8 (f) Based on the state of the fixed test load-bearing part (compression fracture mold test part);

[0101] Figure 8 (h) shows the Figure 8(g) Based on the above, the cavity connecting plates 1-5 are removed and tested;

[0102] Figure 8 (i) shows Figure 8 (h) until the gravel-mixed clay sample 2 undergoes tensile fracture;

[0103] Figure 8 (j) shows the Figure 8 (f) Based on the state of the fixed test load-bearing part (compression fracture mold test part);

[0104] Figure 8 (k) shows the Figure 8 (j) Based on the above, the cavity connecting plates 1-5 are removed and tested;

[0105] Figure 8 (l) shows the Figure 8 (k) until the gravel-mixed clay sample 2 undergoes shear fracture.

[0106] The present invention provides the following embodiments:

[0107] The specific steps of the test using the zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device are as follows:

[0108] S1. Determine the optimum moisture content and maximum dry density;

[0109] Specifically, before conducting the fracture test, it is necessary to determine the optimal moisture content and maximum dry density of gravel-mixed clay in the material yard near the dam site of the high earth-rock dam at different gravel content. Referring to the specification, a heavy-duty compactor was selected to carry out the compaction test of gravel-mixed clay. The compaction hammer mass was 4.5kg, the hammer bottom diameter was 51mm, and the drop height was 457mm. The optimal moisture content and maximum dry density of gravel-mixed clay in the dam site of the high earth-rock dam at 30% to 50% gravel content. As shown in Table 1:

[0110] Table 1 Optimal moisture content and maximum dry density of gravel-mixed clay at 30% to 50% gravel content

[0111]

[0112] S2. Design test conditions:

[0113] When studying the effect of moisture content on fracture characteristics, five levels of 10.34%, 9.87%, 9.43%, 9.08%, and 8.72% were proposed for testing; when studying the effect of dry density on fracture characteristics, 2.16 g / cm 3 , 2.14g / cm 3 , 2.11g / cm 3 , 2.07g / cm3 , 2.03g / cm 3 Five levels were tested; when studying the effect of gravel content on fracture characteristics, five levels of 30%, 35%, 40%, 45% and 50% were proposed for testing; at the same time, other variables were controlled unchanged to design the test conditions.

[0114] S3, such as Figure 8 As shown in (a), the front half of the mold 1-1 and the rear half of the mold 1-2 are combined, and the specific operations are as follows:

[0115] S3.1, front half of combined mold 1-1;

[0116] Specifically, the bolts are screwed into the combination block 1-1-4 and the fixed base plate 1-1-7 on the first seam-making plate 1-1-1 from left to right in sequence, so that the first seam-making plate 1-1-1 is relatively fixed on the supporting box; the bolts are screwed into the combination block 1-1-4 and the fixed base plate 1-1-7 on the second seam-making plate 1-1-2 from right to left in sequence, so that the second seam-making plate 1-1-2 is relatively fixed on the supporting box, and then the first seam-making plate 1-1-1, the second seam-making plate 1-1-2 and the supporting box are combined into the front half 1-1 of the mold.

[0117] S3.2, rear part of combined mold 1-2:

[0118] The same steps as in S3.1 are adopted to combine another set of the first seam-making plate 1-1-1, the second seam-making plate 1-1-2 and the supporting box together to form the rear half 1-2 of the mold.

[0119] S4, such as Figure 8 As shown in (b), assemble the compaction fracture mold 1, and the specific operations are as follows:

[0120] S4.1, connecting the front half of the mold 1-1 and the front floating cavity 1-3 and the rear half of the mold 1-2 and the rear floating cavity 1-4;

[0121] Specifically, bolts are used to fix the three groups of protrusions 1-3-3 with the corresponding first threaded holes 1-1-9, thereby connecting the front half of the mold 1-1 with the front floating cavity 1-3. The same method is used to connect the rear half of the mold 1-2 with the rear floating cavity 1-4.

[0122] S4.2, connect the front floating cavity 1-3 and the rear floating cavity 1-4 and cover them with a rectangular ring wall 1-6;

[0123] Specifically, the front floating cavity 1-3 and the rear floating cavity 1-4 are fixedly connected using the cavity connecting plates 1-5 on the left and right sides, a certain amount of engine oil is applied to the inner side of the rectangular ring wall 1-6 to ensure sufficient lubrication when in contact with the compaction fracture mold test part, and then the rectangular ring wall 1-6 is nested on the outer side of the compaction fracture mold test part, so that the three are tightly combined into one, together forming a compaction fracture mold 1.

[0124] S5, such as Figure 8 As shown in (c), prepare and compact gravel-mixed clay soil sample 2, the specific operation is as follows:

[0125] S5.1. Calculate the required mass of water H, the mass of clay C, the mass of gravel G and the total mass of gravel-mixed clay Y by using the mold volume V, i.e. Y = H + C + G;

[0126] S5.2. Add H mass of water to C mass of clay, place in a sealed box and let stand for 24 hours, add G mass of gravel to it, stir quickly, and place in a sealed box again and let stand for 24 hours;

[0127] S5.3. Add the compaction fracture mold test part N times. After adding the gravel-mixed clay each time, use the Z-shaped compaction plates 1-7 to compact the gravel-mixed clay.

[0128] S6, such as Figure 8 As shown in (d), the compacted fracture mold 1 is transferred to the hollow test tank 7;

[0129] Specifically, the compacted gravel-mixed clay soil sample 2 is placed together with the compaction fracture mold 1 into the hollow test tank 7 through a hanging rope. At this time, since there is no water in the hollow test tank 7, the compaction fracture mold 1 is in contact with the bottom of the hollow test tank 7.

[0130] S7, such as Figure 8 As shown in (e), the Z-shaped compacting plate 1-7 and the rectangular ring wall 1-6 are removed;

[0131] Specifically, the Z-shaped compaction plate 1-7 above the gravel-mixed clay soil sample 2 and the rectangular annular wall 1-6 sleeved on the outside of the front half 1-1 of the mold and the rear half 1-2 of the mold are removed, but the cavity connecting plate 1-5 is still kept in a state of being connected to the front half 1-1 of the mold and the rear half 1-2 of the mold. At this time, the front half 1-1 of the mold and the rear half 1-2 of the mold cannot be separated from each other.

[0132] S8, such as Figure 8 As shown in (f), the compaction fracture mold test part is suspended, and the specific operation is as follows:

[0133] S8.1. Fill a certain amount of hydrogen into the two airbag groups 1-3-4 at the bottom of the front floating cavity 1-3 and the rear floating cavity 1-4, so that the front floating cavity 1-3 and the rear floating cavity 1-4 are lifted up due to the protrusion of the airbag groups 1-3-4;

[0134] S8.2, open the water inlet hole 7-1, close the water outlet hole 7-2, fill the groove of the hollow test tank 7 with water, and compact the fracture mold test part to continue to float up as the water surface rises under the action of buoyancy;

[0135] S8.3. By changing the hydrogen content in the airbags at different positions in the front floating cavity 1-3 and the rear floating cavity 1-4, the floating condition of the test part of the compaction fracture mold is adjusted, and the compaction fracture mold 1 is leveled with the help of the four horizontal bubbles 1-3-2 on the front floating cavity 1-3 and the rear floating cavity 1-4.

[0136] Furthermore, in the above technical solution, the hydrogen filling amount of the two airbag groups 1-3-4 is obtained by calculation, and the steps are as follows:

[0137] S8.1.1. Collect the mass A of the compacted fracture mold test part and the mass Y of gravel-mixed clay soil sample 2, and obtain the total mass of the test body consisting of the compacted fracture mold test part and gravel-mixed clay soil sample 2 as A+Y;

[0138] S8.1.1. Substitute A+Y into the following expression and solve for the buoyancy F(buoyancy) corresponding to A+Y;

[0139] A+Y=F(float)=G(discharge)=ρ(water)gV(discharge)

[0140] Wherein, ρ(water) represents the density of the liquid filled in the hollow test tank 7, and g is the acceleration due to gravity, which is 9.8 m / s 2 , V(displaced) represents the volume of liquid displaced by the test subject, and G(displaced) represents the displacement of the test subject when it floats on the water surface against gravity;

[0141] The inference is:

[0142] V(row)=(A+Y) / ρ(water)g

[0143] S8.1.2. Substitute the volume V(displaced) of the liquid displaced by the test subject when it floats into the following formula to calculate the minimum mass M of hydrogen that needs to be filled into the test subject to overcome gravity and achieve floating;

[0144] M=ρ(gas)V(exhaust)

[0145] Among them, ρ(gas) represents the density of hydrogen, which is 0.089g / m 3 .

[0146] Further, in the above technical solution, the leveling method described in S8.3 is implemented based on the structure of the airbag group, which includes a plurality of airbags distributed in a rectangular array for filling with hydrogen;

[0147] A diaphragm is arranged between the multiple airbags, and a channel is arranged on the diaphragm, and a solenoid valve is embedded in the channel. Each airbag is provided with an independent inflation and deflation hole, so that the multiple airbags can be inflated and deflated synchronously or the gas volume in the airbags in a local area can be adjusted;

[0148] The connection end of the solenoid valve is electrically connected to a remote control chip, and the number of a specific airbag is input through the remote control to increase or decrease the amount of hydrogen filled therein.

[0149] Furthermore, in the above technical solution, the following conditions are met when the two airbag groups 1-3-4 are inflated:

[0150] When the upper and lower positions of the test body on the water surface are finely adjusted, multiple solenoid valves are opened to allow multiple airbags to communicate with each other, and the hydrogen mass P in any airbag is increased, and the hydrogen in other airbags is supplemented accordingly, and the overall height of the test body on the water surface is adjusted up and down;

[0151] When the solenoid valve between one of the airbags and the adjacent airbag fails to open due to signal control or failure, resulting in a concave shape relative to the outside, the solenoid valve on the airbag is controlled to open, and the mass of hydrogen in each of the other airbags is reduced by P / (n-1), where n is the number of airbags in each airbag group 1-3-4. For example, in this embodiment, the two airbag groups 1-3-4 each contain 32 airbags. When the compaction fracture mold 1 needs to be leveled, the mass of hydrogen in one airbag is increased by P, and the mass of hydrogen in each of the other airbags is reduced by P / 31;

[0152] When the test body is tilted and needs to be leveled, the solenoid valve is closed, the hydrogen mass P of a certain airbag in the lower side area of ​​the compaction fracture mold 1 is increased, and the increased hydrogen mass P is filled into the corresponding airbag from the external gas transmission pipe.

[0153] At this point, the entire core wall gravel-mixed clay tensile-shear fracture test device has been assembled;

[0154] S9. Complete the assembly of the test device and select the test type:

[0155] If a tensile rupture test is performed, proceed to S9.1; if a shear rupture test is performed, proceed to S9.2;

[0156] S9.1. Conduct tensile fracture test on core wall gravel-mixed clay:

[0157] 1. The tensile fracture test operation process of gravel-mixed clay sample 2 is as follows:

[0158] S9.1.1: Figure 8 (g) shows the fixed compression fracture mold test part:

[0159] By controlling the front control part 5-2 and the rear control part 6-2, the output ends of the front connection part 5-1 and the rear connection part 6-1 are extended respectively, gradually close to the front axial connection hole 1-1-8 and the rear lateral connection hole 1-2-0, and the hydrogen content filled in the two groups of airbag groups 1-3-4 is finely adjusted to make the axial connection hole 1-1-8 and the lateral connection hole 1-2-0 respectively consistent in height with the front connection part 5-1 and the rear connection part 6-1, and the front connection part 5-1 and the rear connection part 6-1 are extended again until they are fixedly connected with the compaction fracture mold test part;

[0160] S9.1.2 If Figure 8 As shown in (h), remove the cavity connecting plate 1-5 and conduct the test:

[0161] Remove the cavity connection plates 1-5 connecting the front floating cavity 1-3 and the rear floating cavity 1-4 and located on the left and right sides, open the front control unit 5-2 and the rear control unit 6-2, pull the front connection unit 5-1 and the rear connection unit 6-1 at a certain rate; record the data measured by the stress and displacement sensors connected to the front connection unit 5-1 and the rear connection unit 6-1;

[0162] S9.1.3: Figure 8 (i) until the gravel-mixed clay sample 2 undergoes tensile fracture and the data is processed:

[0163] The stress and displacement are recorded until the gravel-mixed clay sample 2 undergoes tensile fracture. The stress and displacement data are then processed to obtain the stress F (tensile) and displacement L (tensile) of the gravel-mixed clay sample 2 in the tensile fracture test. The expressions are as follows:

[0164] F(pull)=(|F5|+|F6|) / 2

[0165] L(pull)=(|L5|+|L6|) / 2

[0166] Wherein, F5 and F6 represent stress data recorded by the front connecting portion 5-1 and the rear connecting portion 6-1 respectively; L5 and L6 represent displacement data recorded by the front connecting portion 5-1 and the rear connecting portion 6-1 respectively;

[0167] According to the F (tensile) and L (tensile) values, the stress-strain curve of the tensile fracture of gravel-mixed clay sample 2 was obtained. The characteristic parameters of the gravel-mixed clay in the high earth-rock dam during the tensile fracture process were analyzed through the tensile fracture stress-strain curve, and the characteristic parameters included fracture toughness and fracture energy. Thus, the tensile fracture characteristics of gravel-mixed clay sample 2 in the high earth-rock dam were fully understood.

[0168] Furthermore, in the above technical solution, the pulling rate of the front connecting part 5-1 and the rear connecting part 6-1 is set to multiple gears, which is used to study the influence of different loading rates on the tensile fracture characteristics of the gravel-mixed clay soil sample 2; for example, the multiple gears are set to gear 1 (0.005mm / s), gear 2 (0.01mm / s), gear 3 (0.02mm / s), gear 4 (0.05mm / s), and gear 5 (0.1mm / s), respectively, which can simulate the stress conditions of the gravel-mixed clay at different heights of the core wall of the high earth-rock dam during the construction and operation periods. Since the core wall dam is relatively high, the uneven settlement of the gravel-mixed clay in the middle and low parts of the core wall is relatively small, and the test can be carried out at gear 1 or 2; the uneven settlement of the gravel-mixed clay in the middle and high parts of the core wall is relatively large, and the test can be carried out at gear 4 or 5.

[0169] It should be noted that when the front connecting portion 5-1 and the rear connecting portion 6-1 are respectively at level 1 (0.005 mm / s), since the front and rear are pulled simultaneously, the loading rate for the effect on the tensile fracture characteristics of gravel-mixed clay studied is 0.01 mm / s. The same is true for other levels.

[0170] S9.2. Carry out shear fracture test on core wall with gravel-mixed clay:

[0171] 2. The shear fracture test operation process for gravel-mixed clay sample 2 is as follows:

[0172] S9.2.1. Figure 8 (j) shows the fixed compaction fracture mold test part:

[0173] By controlling the left control part 3-2 and the right control part 4-2, the output ends of the left connection part 3-1 and the right control part 4-2 are extended respectively, gradually close to the axial connection hole 1-1-8 on the left and the lateral connection hole 1-2-0 on the right, and the hydrogen content filled in the two groups of airbag groups 1-3-4 is finely adjusted to make the axial connection hole 1-1-8 and the lateral connection hole 1-2-0 respectively consistent in height with the left connection part 3-1 and the right connection part 4-1, and the left connection part 3-1 and the right connection part 4-1 are extended again until they are fixedly connected with the compaction fracture mold test part;

[0174] S9.2.2 If Figure 8 As shown in (k), the cavity connecting plates 1-5 are removed to expose the prefabricated seams and conduct the test:

[0175] Remove the cavity connection plates 1-5 connecting the front floating cavity 1-3 and the rear floating cavity 1-4 and located on the left and right sides thereof. On the premise that the combination block 1-1-4 is disconnected from the carrier box, hook the hook holes provided on the positioning blocks 1-1-3 provided on both sides by hooking the clamps, and remove the first seam-making plate 1-1-1 and the second seam-making plate 1-1-2 respectively; open the left control unit 3-2 and the right control unit 4-2, and push the left connection unit 3-1 and the right connection unit 4-1 at a certain rate; record the data measured by the stress and displacement sensors inside the left connection unit 3-1 and the right connection unit 4-1;

[0176] S9.2.3: Figure 8 As shown in (l), until the gravel-mixed clay sample 2 undergoes shear fracture and the data is processed:

[0177] The stress and displacement are recorded until the gravel-mixed clay sample 2 undergoes shear fracture. The stress and displacement data are then processed to obtain the stress F (shear) and displacement L (shear) of the gravel-mixed clay sample 2 in the shear fracture test. The expressions are as follows:

[0178] F(shear)=(|F3|+|F4|) / 2

[0179] L(shear)=(|L3|+|L4|) / 2

[0180] Wherein, F3 and F4 represent the stress data recorded by the left connecting part 3-1 and the right connecting part 4-1 respectively; L3 and L4 represent the displacement data recorded by the left connecting part 3-1 and the right connecting part 4-1 respectively;

[0181] According to the F (shear) and L (shear) values, the stress-strain curve of shear fracture of gravel-mixed clay sample 2 was obtained. The characteristic parameters of gravel-mixed clay in the high earth-rock dam during shear fracture were analyzed through the shear fracture stress-strain curve, and the characteristic parameters included fracture toughness and fracture energy. Thus, the shear fracture characteristics of gravel-mixed clay sample 2 in the high earth-rock dam were fully understood.

[0182] Furthermore, in the above technical solution, the advancement rate of the left connecting part 3-1 and the right connecting part 4-1 is set to multiple gears, which is used to study the influence of different loading rates on the shear fracture characteristics of the gravel-mixed clay soil sample 2. For example, the multiple gears are set to gear 1 (0.005mm / s), gear 2 (0.01mm / s), gear 3 (0.02mm / s), gear 4 (0.05mm / s), and gear 5 (0.1mm / s), respectively, which can simulate the stress conditions of the gravel-mixed clay at different heights of the core wall of the high earth-rock dam during the construction and operation periods. Since the core wall dam is relatively high, the uneven settlement of the gravel-mixed clay in the middle and low parts of the core wall is relatively small, and the test can be carried out at gear 1 or 2; the uneven settlement of the gravel-mixed clay in the middle and high parts of the core wall is relatively large, and the test can be carried out at gear 4 or 5.

[0183] It should be noted that when the left connecting part 3-1 and the right connecting part 4-1 are respectively at level 1 (0.005 mm / s), since the front and rear are advanced simultaneously, the loading rate for the effect on the shear fracture characteristics of gravel-mixed clay studied is 0.01 mm / s. The same is true for other levels.

[0184] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. Zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device, characterized by: The invention comprises a compaction fracture mold (1) and a hollow test tank (7), wherein the compaction fracture mold (1) is used to prepare a gravel-mixed clay soil sample (2), and comprises a test bearing part, a rectangular annular wall (1-6) and a Z-shaped compaction plate (1-7), and a rectangular groove is provided at the center of the top of the hollow test tank (7), and the groove is filled with water that can make the test bearing part loaded with the gravel-mixed clay soil sample (2) float; The prepared gravel-mixed clay soil sample (2) has a soil sample fracture section (2-1), two sides of which are respectively provided as a soil sample front end section (2-2) and a soil sample rear end section (2-3); The test bearing part comprises a front half of a mold (1-1), a rear half of a mold (1-2), a front floating cavity (1-3), a rear floating cavity (1-4) and a cavity connecting plate (1-5), wherein the front half of the mold (1-1) and the rear half of the mold (1-2) are detachably mounted on the front floating cavity (1-3) and the rear floating cavity (1-4), respectively, and the front floating cavity (1-3) and the rear floating cavity (1-4) are detachably connected via the cavity connecting plate (1-5); The combined structure of the front half (1-1) of the mold and the front floating cavity (1-3) is the same as the combined structure of the rear half (1-2) of the mold and the rear floating cavity (1-4), and the two combined structures are centrally symmetrically distributed. The bottoms of the front floating cavity (1-3) and the rear floating cavity (1-4) are open and embedded with air bag groups (1-3-4) for adjusting the buoyancy of the front floating cavity (1-3) and the rear floating cavity (1-4) and the floating angle on the water surface. The front half (1-1) of the mold and the front floating cavity (1-3) are both provided with level bubbles (1-3-2) for detecting the levelness of the test bearing part loaded with gravel-mixed clay soil sample (2); The left and right sides of the hollow test trough (7) are respectively provided with a left propeller (3) and a right propeller (4) which are symmetrically distributed in the center. The left propeller (3) and the right propeller (4) respectively propel the front half (1-1) and the rear half (1-2) of the mold toward the center of the test device, so as to apply a shear force to the gravel-mixed clay soil sample (2); the front and rear sides of the hollow test trough (7) are respectively provided with a front puller (5) and a rear puller (6) which are symmetrically distributed in the axis. The front puller (5) and the rear puller (6) respectively pull the front half (1-1) and the rear half (1-2) of the mold toward the front and rear sides of the test device, so as to apply a tensile force to the gravel-mixed clay soil sample (2).

2. The zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 1 is characterized by: The front half (1-1) and the rear half (1-2) of the mold both include a carrying box composed of a lateral push plate (1-1-5), an axial pull plate (1-1-6) and a fixed bottom plate (1-1-7), and the lateral push plate (1-1-5) and the axial pull plate (1-1-6) are respectively vertically fixed on adjacent side walls of the fixed bottom plate (1-1-7), and the middle parts of the lateral push plate (1-1-5) and the axial pull plate (1-1-6) are respectively provided with side The first and second seam-making plates (1-1-1 and 1-2) are respectively provided with a first seam-making plate (1-1-1) and a second seam-making plate (1-1-2) which are symmetrically distributed on the axis, and are used to pre-form seams on the left and right sides of the soil sample. The first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) are both detachably mounted on the fixed base plate (1-1-7); Both ends of one side of the fixed bottom plate (1-1-7) are provided with notches, the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) are respectively embedded in the notches on both sides, and the thickness of the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) match the depth of the notches, a gap is reserved between the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) on the same fixed bottom plate (1-1-7), and the two corresponding groups of the first seam-making plates (1-1-1) and the second seam-making plates (1-1-2) on the front and rear fixed bottom plates (1-1-7) are fitted with each other.

3. The zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 1 is characterized by: The Z-shaped pressing plate (1-7) is made of aluminum alloy, and has a pressing plate middle gap (1-7-1) on both sides thereof, and the pressing plate middle gap (1-7-1) is adapted to the shape of two groups of first seam-making plates (1-1-1) and second seam-making plates (1-2-1) corresponding to the front and rear fixed bottom plates (1-1-7) after being bonded to each other; The Z-shaped compacting plate (1-7) is adapted to the shapes of the front half (1-1) and the rear half (1-2) of the mold; A pressing plate end handle (1-7-2) is provided on the top of the Z-shaped pressing plate (1-7).

4. The zero-friction high earth-rockfill dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 2 is characterized by: The first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) are both provided with positioning blocks (1-1-3) and assembly blocks (1-1-4), wherein the assembly blocks (1-1-4) are located on the lower side surfaces of the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2), and are connected and assembled with the fixed bottom plate (1-1-7) by bolts; The positioning block (1-1-3) is located in the middle of the side of the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2), and has hook holes running through its surface; The rectangular ring wall (1-6) is a rectangular annular aluminum alloy ring body, and positioning grooves are provided at the bottom of both sides thereof. The positioning grooves match the mutually fitting structure of two groups of corresponding first seam-making plates (1-1-1) and second seam-making plates (1-1-2) on the front and rear fixed bottom plates (1-1-7). The interior of the rectangular ring wall (1-6) fits the exterior of the test bearing part, and after being sleeved on the exterior of the test bearing part, the top of the rectangular ring wall (1-6) is flush with the test bearing part.

5. The zero-friction high earth-rockfill dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 2, characterized in that: The three side surfaces of the fixed bottom plate (1-1-7) are each provided with a first threaded hole (1-1-9), and the tops of the front floating cavity (1-3) and the rear floating cavity (1-4) are each provided with a protrusion (1-3-3) matching the three groups of first threaded holes (1-1-9), the carrying box is clamped on the inner side of the three groups of protrusions (1-3-3), and is fixedly connected to the front floating cavity (1-3) or the rear floating cavity (1-4) by bolts; Second threaded holes (1-3-1) are provided at both ends of the opposite sides of the front floating cavity (1-3) and the rear floating cavity (1-4), and the front floating cavity (1-3) or the rear floating cavity (1-4) is fixedly connected via a cavity connecting plate (1-5) and bolts.

6. The zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 1, characterized in that: The airbag group (1-3-4) includes a plurality of airbag bodies distributed in a rectangular array, made of rubber material, and filled with hydrogen; A diaphragm is arranged between the multiple airbags, and a channel is arranged on the diaphragm, and an electromagnetic valve is embedded in the channel. Each airbag is provided with an independent inflation and deflation hole, so that the multiple airbags can be inflated and deflated synchronously or the gas volume in the airbags in the local area can be adjusted.

7. The zero-friction high earth-rockfill dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 1, characterized in that: The outer wall of the hollow test tank (7) is provided with a water inlet hole (7-1) and a water outlet hole (7-2) penetrating the groove, and the water inlet hole (7-1) and the water outlet hole (7-2) are respectively used to supplement and replace the water in the groove.

8. The zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 1, characterized in that: The left-side propeller (3), the right-side propeller (4), the front-side retractor (5) and the rear-side retractor (6) are installed on the hollow test tank (7) via a lifting mechanism; The left-side thruster (3) comprises a left-side connecting portion (3-1) and a left-side control portion (3-2) for connecting and controlling the extension and retraction of the output end of the left-side connecting portion (3-1); The right thruster (4) comprises a right connecting portion (4-1) and a right control portion (4-2) used for connecting and controlling the extension and retraction of the output end of the right connecting portion (4-1); The front retractor (5) comprises a front connecting portion (5-1) and a front controlling portion (5-2) for connecting and controlling the extension and retraction of the output end of the front connecting portion (5-1); The rear retractor (6) comprises a rear connecting portion (6-1) and a rear controlling portion (6-2) for connecting and controlling the extension and retraction of the output end of the rear connecting portion (6-1); The output ends of the left connecting portion (3-1) and the right connecting portion (4-1) are respectively connected to the lateral connecting holes (1-2-0) on the two carrying boxes; The output ends of the front connecting portion (5-1) and the rear connecting portion (6-1) are respectively connected to the axial connecting holes (1-1-8) on the two carrying boxes.

9. The zero-friction high earth-rockfill dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 8, characterized in that: The left connecting part (3-1), the right connecting part (4-1), the front connecting part (5-1) and the rear connecting part (6-1) are all configured as telescopic drive mechanisms, which use at least one of a cylinder, an electric push rod, a hydraulic cylinder and a linear module.

10. The zero-friction high earth-rockfill dam core wall gravel-mixed clay tensile-shear fracture test device according to claim 8, characterized in that: The connection ends of the left connection part (3-1), the right connection part (4-1), the front connection part (5-1) and the rear connection part (6-1) are all provided with displacement sensors and stress sensors, which are respectively used to sense the displacement and stress value of the left connection part (3-1), the right connection part (4-1), the front connection part (5-1) and the rear connection part (6-1) during telescopic operation.

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