Zero-friction tensile-shear fracture testing device for high earth-rockfill dam core wall mixed clay

Abstract

The present application relates to a zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device, comprising a compaction fracture mold and a hollow test tank, wherein the compaction fracture mold is used for making a gravel-mixed clay soil sample, and comprises a test bearing part, a rectangular ring wall and a Z-shaped compaction plate, and a rectangular recess is formed at the top center of the hollow test tank. Through the design of the floating cavity, the compaction fracture mold test part is separated from the working platform by skillfully using the air bag group and the buoyancy principle, thereby fundamentally solving the friction between the mold and the platform, greatly enriching the test means of the fracture characteristics of the gravel-mixed clay, the design of multiple air bags in the air bag group facilitates the leveling of the test part of the compaction fracture mold, the operation is simple and convenient, the detection accuracy can be significantly improved, the tensile fracture and shear fracture characteristics are measured at the same time, and the accurate tensile fracture characteristics and shear fracture characteristics of the high earth-rock dam gravel-mixed clay soil sample are analyzed.

Description

TECHNICAL FIELD

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

[0002] In the planning and construction of high dams, earth-rock dams have a higher and higher proportion due to their good foundation adaptability and economical building materials. China has the largest number of high earth core wall rockfill dams, and most of them are concentrated in the southwestern region of China. According to statistics, the core wall dams with a height of more than 100.0m in service in China include Shiziping (136.0m), Xiaolangdi (160.0m), Pubugou (186.0m), Nuozhadu (261.5m) and Lianghekou (295.0m), etc. The core wall dams under construction or planning with a height of more than 300m include Ruiguang (315.0m), Gushui (305.0m), Jingguan (346.0m) and Qizong (356.0m), etc.

[0003] Traditional low and medium earth-rock dams often use compacted pure clay core wall as the impermeable system, but as the construction height increases, the poor compressive performance of clay gradually becomes a disadvantage, and the uneven settlement of the core wall and the rockfill body will cause cracks in the core wall clay. High earth-rock dams often mix gravel in the core wall to improve the compressive performance of the impermeable core wall and reduce uneven settlement. The essence of core wall cracking is shear failure, tensile failure or shear-tensile composite failure of the soil body when the stress and strain it bears exceed its tensile strength or shear strength. At present, there are few related research results on the fracture characteristics of mixed gravel clay in the core wall, therefore, it is of great engineering significance and practical value to study the fracture characteristics of mixed gravel clay and explore the crack evolution law of mixed gravel clay.

[0004] At present, soil fracture test devices mainly focus on the fracture characteristics of clay or sand, and there is still a blank in the test device for studying the fracture characteristics of mixed gravel clay in the core wall of high earth-rock dams, and the tensile fracture and shear fracture characteristics of mixed gravel clay cannot be measured. In addition, how to eliminate the friction between the mold and the base plate has always been a key problem that needs to be solved in the 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 mixed gravel clay in the core wall of high earth-rock dams in the southwestern region, to fill the gap in the existing mixed gravel clay fracture test device and eliminate friction as much as possible. SUMMARY

[0005] The present application mainly solves the problem of the deficiency of the existing gravel clay test technology, and provides a zero-friction high earth-rock dam core wall gravel clay tensile-shear fracture test device, which can measure the tensile fracture characteristics of the gravel clay and the shear fracture characteristics of the gravel clay, and has significantly enhanced functionality and practicability, is multi-purpose, reduces the cost of purchasing test equipment, and fundamentally solves the friction between the mold and the floor through the principle of buoyancy, greatly enriches the test means of the fracture characteristics of the gravel clay, and improves the detection accuracy.

[0006] To solve the above technical problems, the technical scheme adopted by the present application is:

[0007] The zero-friction high earth-rock dam core wall gravel clay tensile-shear fracture test device comprises a compaction fracture mold and a hollow test tank, wherein the compaction fracture mold is used for making a gravel clay soil sample, and comprises a test bearing part and a rectangular ring wall and a Z-shaped compaction plate; a rectangular groove is formed at the center of the top of the hollow test tank; and the groove is filled with water that can make the test bearing part loaded with the gravel clay soil sample float.

[0008] The prepared gravel clay soil sample has a soil sample fracture section, and the two sides of the soil sample fracture section are respectively provided with a soil sample front end part and a soil sample rear end part.

[0009] The test bearing part comprises a mold front half, a mold rear half, a front floating cavity, a rear floating cavity and a cavity connecting plate, wherein the mold front half and the mold rear half are respectively detachably installed on the front floating cavity and the rear floating cavity, and the front floating cavity and the rear floating cavity are detachably connected through the cavity connecting plate.

[0010] The combination structure of the mold front half and the front floating cavity is the same as that of the mold rear half and the rear floating cavity, and the two combination structures are centrally symmetrically distributed; the bottom openings of the front floating cavity and the rear floating cavity are embedded with a gas bag group for adjusting the buoyancy of the front floating cavity and the rear floating cavity and the angle of the front floating cavity and the rear floating cavity floating on the water surface; and horizontal air bubbles are arranged on the mold front half and the front floating cavity for detecting the levelness of the test bearing part loaded with the gravel clay soil sample.

[0011] The left and right sides of the hollow test tank are respectively provided with left and right side thrusters which are centrally symmetrically distributed, and the left and right side thrusters respectively push the mold front half and the mold rear half to the center of the test device for applying shear force to the gravel clay soil sample; and the front and rear sides of the hollow test tank are respectively provided with front and rear side pullers which are axially symmetrically distributed, and the front and rear side pullers respectively pull the mold front half and the mold rear half to the front and rear sides of the test device for applying tensile force to the gravel clay soil sample.

[0012] Preferably, the mold front half and the mold rear half each comprise a bearing 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 vertically fixed on the adjacent side walls of the fixed bottom plate respectively, the middle part of the lateral push plate and the axial pull plate is respectively provided with a lateral connecting hole and an axial connecting hole, the side of the fixed bottom plate away from the axial pull plate is respectively provided with a first seam making plate and a second seam making plate which are axially symmetrically distributed, for pre-making seams on the left and right sides of the soil sample, and the first seam making plate and the second seam making plate are detachably installed with the fixed bottom plate.

[0013] The side of the fixed bottom plate is provided with notches at both ends, the first seam making plate and the second seam making plate are respectively embedded in the notches at both sides, and the thickness of the first seam making plate and the second seam making plate is consistent with the depth of the notches, and a gap is reserved between the first seam making plate and the second seam making plate on the same fixed bottom plate, and the corresponding two groups of first seam making plates and second seam making plates on the front and rear fixed bottom plates are mutually attached.

[0014] Preferably, the Z-shaped compaction plate is made of aluminum alloy material, and the two sides of the Z-shaped compaction plate are provided with plate middle gaps, and the plate middle gaps are adapted to the shape after the corresponding two groups of first seam making plates and second seam making plates on the front and rear fixed bottom plates are mutually attached.

[0015] The Z-shaped compaction plate is adapted to the shape of the mold front half and the mold rear half.

[0016] The Z-shaped compaction plate is provided with a plate end handle at the top.

[0017] Preferably, the first seam making plate and the second seam making plate are each provided with a positioning block and a combination block, and the combination block is located on the side surface of the lower part of the first seam making plate and the second seam making plate, and is combined with the fixed bottom plate through bolts.

[0018] The positioning block is located on the middle part of the side surface of the first seam making plate and the second seam making plate, and a hook pulling hole penetrates the surface of the positioning block.

[0019] The oblong ring wall is an oblong annular aluminum alloy ring body, and the two sides and the bottom of the oblong ring wall are provided with positioning grooves which are matched with the structure of the corresponding two groups of first seam making plates and second seam making plates which are mutually attached on the front and rear fixed bottom plates, the inside of the oblong ring wall is attached to the outside of the test bearing part, and the top of the oblong ring wall is flush with the test bearing part after being sleeved on the outside of the test bearing part.

[0020] Preferably, the first threaded holes are provided on the three side surfaces of the fixed bottom plate, and the top of the front floating cavity and the rear floating cavity is provided with a protruding part matched with the three groups of first threaded holes, and the bearing box is clamped on the inside of the three groups of protruding parts and is fixedly connected with the front floating cavity or the rear floating cavity through bolts.

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

[0022] Preferably, the air bag group comprises a plurality of air bag bodies arranged in a rectangular array, which are made of rubber and filled with hydrogen gas.

[0023] A diaphragm is arranged between the plurality of air bag bodies, and a channel is arranged on the diaphragm, and an electromagnetic valve is embedded in the channel, and an independent inflation and deflation hole is arranged on each air bag body, so that the plurality of air bag bodies can be inflated and deflated synchronously or the amount of gas in the air bag bodies in the local area can be adjusted.

[0024] Preferably, water inlet holes and water outlet holes are formed in the recessed grooves of the outer wall of the hollow test tank, and the water inlet holes and the water outlet holes are respectively used for supplementing and replacing the water in the recessed grooves.

[0025] Preferably, the left propeller, the right propeller, the front puller and the rear puller are installed on the hollow test tank through a lifting mechanism.

[0026] The left propeller comprises a left connecting part and a left control part for connecting and controlling the extension and retraction of the output end of the left connecting part.

[0027] The right propeller comprises a right connecting part and a right control part for connecting and controlling the extension and retraction of the output end of the right connecting part.

[0028] The front puller comprises a front connecting part and a front control part for connecting and controlling the extension and retraction of the output end of the front connecting part.

[0029] The rear puller comprises a rear connecting part and a rear control part for connecting and controlling the extension and retraction of the output end of the rear connecting part.

[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 bearing boxes.

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

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

[0033] Preferably, the connecting ends of the left connecting part, the right connecting part, the front connecting part and the rear connecting part are respectively provided with displacement sensors and stress sensors for sensing the displacement and stress values during the telescopic operation of the left connecting part, the right connecting part, the front connecting part and the rear connecting part.

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

[0035] 1. By the design of the floating cavity, the air bag group and the buoyancy principle are ingeniously utilized to separate the compaction fracture mold test part from the working platform, thereby fundamentally solving the friction between the mold and the platform, greatly enriching the test means of the gravelly clay fracture characteristics, the design of multiple air bags in the air bag group facilitates the leveling of the test part of the compaction fracture mold, the operation is simple and convenient, the detection accuracy can be significantly improved, and the tensile fracture characteristics and shear fracture characteristics of the gravelly clay soil sample of the high earth-rock dam can be accurately analyzed;

[0036] 2. By setting the combined compaction fracture mold, not only can it be applied to the production of gravelly clay soil samples, but also the test bearing part as the test part of the compaction fracture mold cooperates with the hollow test tank to work, which can measure the tensile fracture characteristics of the gravelly clay and the shear fracture characteristics of the gravelly clay, thereby making up for the blank of the existing gravelly clay fracture test device, significantly enhancing the functionality and practicality of the device, one machine with multiple functions, and reducing the cost of purchasing test equipment;

[0037] 3. The direction and mode of force applied to the test part of the compaction fracture mold are changed by the thrusters on both sides and the pullers in front and back, the rate of tensile fracture and shear fracture of the gravelly clay soil sample is controlled, and convenience is provided for studying the influence law of different loading rates on the tensile fracture and shear fracture of the gravelly clay. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The overall structure schematic diagram of the tensile-shear fracture test device (omitting the cavity connecting plate, the rectangular ring wall and the Z-shaped compaction plate) provided by the present application is shown.

[0039] Figure 2 The overall structure schematic diagram of the compaction fracture mold in the present application is shown.

[0040] Figure 3 The structure schematic diagram of the test bearing part (omitting the cavity connecting plate) in the present application is shown.

[0041] Figure 4 The distribution structure of the air bag group in the present application and the inflation process change demonstration effect diagram are shown. Figure 3 The explosion diagram of the structure shown in the present application is shown.

[0042] Figure 5 The distribution structure of the air bag group in the present application and the inflation process change demonstration effect diagram are shown.

[0043] Figure 6 The structure schematic diagram of the gravelly clay soil sample in the present application is shown.

[0044] Figure 7The connection structure diagram of the left propeller, the right propeller, the front puller, the rear puller and the hollow test tank in the application.

[0045] Figure 8 The test process diagram of the zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device in the application.

[0046] In the figure:

[0047] 1, compaction fracture mold;

[0048] 1-1, mold front half; 1-2, mold rear half;

[0049] 1-1-1, first seam forming plate; 1-1-2, second seam forming plate; 1-1-3, positioning block; 1-1-4, combined block; 1-1-5, lateral push plate; 1-1-6, axial pull plate; 1-1-7, fixed bottom plate; 1-1-8, axial connection hole; 1-1-9, first threaded hole; 1-2-0, lateral connection 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, protruding part; 1-3-4, air bag group;

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

[0053] 1-7, Z-shaped compaction plate; 1-7-1, compaction plate middle gap; 1-7-2, compaction plate end handle;

[0054] 2, gravel-mixed clay soil sample; 2-1, soil sample fracture section; 2-2, soil sample front end part; 2-3, soil sample rear end part;

[0055] 3, left propeller; 3-1, left side connecting part; 3-2, left side control part;

[0056] 4, right propeller; 4-1, right side connecting part; 4-2, right side control part;

[0057] 5, front puller; 5-1, front side connecting part; 5-2, front side control part;

[0058] 6, rear puller; 6-1, rear side connecting part; 6-2, rear side control part;

[0059] 7, hollow test tank; 7-1, water inlet hole; 7-2, water outlet hole. DETAILED DESCRIPTION

[0060] The application will be further described in detail below in combination with the drawings and specific preferred embodiments.

[0061] In the description of the present application, 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, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and "first", "second" and the like do not represent the importance of the parts, and therefore cannot be understood as a limitation on the present application. The specific dimensions used in the embodiments are only for the purpose of illustrating the technical solutions and do not limit the protection scope of the present application.

[0062] As shown in Figures 1-7 The zero-friction high earth-rock dam core wall gravel-mixed clay tensile-shear fracture test device includes a compaction fracture mold 1 and a hollow test tank 7, wherein the compaction fracture mold 1 is used to make a gravel-mixed clay soil sample 2, and includes a test bearing part and a rectangular ring wall 1-6 and a Z-shaped compaction plate 1-7. The compaction fracture mold 1 is a center-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 of the compaction fracture mold 1 after the rectangular ring wall 1-6 and the Z-shaped compaction plate 1-7 are disassembled after the sample preparation is completed. A rectangular groove is formed at the center position of the top of the hollow test tank 7. The hollow test tank 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 make the test bearing part loaded with the gravel-mixed clay soil sample 2 float;

[0063] The prepared gravel-mixed clay soil sample 2 has a soil sample fracture section 2-1, and the two sides thereof are respectively provided with a soil sample front end part 2-2 and a soil sample rear end part 2-3. The gravel-mixed clay soil sample 2 prepared by the present application has a center-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 actual tensile fracture or shear fracture;

[0064] The test bearing part comprises a mold front half 1-1, a mold rear half 1-2, a front floating cavity 1-3, a rear floating cavity 1-4 and a cavity connecting plate 1-5, wherein the mold front half 1-1 and the mold rear half 1-2 are respectively detachably installed on the front floating cavity 1-3 and the rear floating cavity 1-4, 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 mold front half 1-1 and the mold rear half 1-2 are respectively a front half and a rear half of a mold, and are correspondingly arranged at a front end and a rear end of the gravelly clay soil sample 2, and can respectively realize axial pulling and lateral pushing of the front end part 2-2 and the rear end part 2-3; during the process of making the gravelly clay soil sample 2 and transferring to the hollow test tank 7, the front floating cavity 1-3 and the rear floating cavity 1-4 are connected through the cavity connecting plate 1-5 to form a horizontal and firm whole 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 relatively with the mold front half 1-1 and the mold rear half 1-2; in the working state, the front floating cavity 1-3 and the rear floating cavity 1-4 are in a fixed connection state with the mold front half 1-1 and the mold rear half 1-2 respectively, so that the mold front half 1-1 and the mold rear half 1-2 stably float on the water body;

[0065] The test bearing part cooperates with the rectangular ring wall 1-6 and the Z-shaped compaction plate 1-7 to compact the gravelly clay material of the core wall of the high earth-rock dam to form the gravelly 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 gravelly clay soil sample 2 is loaded in the test bearing part;

[0066] The test bearing part is made of aluminum alloy material, which has the advantages of high strength and low density, can reduce the influence of self weight on the test as much as possible, and is convenient for measuring the fracture characteristics of the gravelly clay during the process of stretching or shearing the gravelly clay soil sample 2;

[0067] The combination structure of the mold front half 1-1 and the front floating cavity 1-3 and the combination structure of the mold rear half 1-2 and the rear floating cavity 1-4 are the same, and the two combination structures are centrally symmetrically distributed, the bottom of the front floating cavity 1-3 and the rear floating cavity 1-4 is open and embedded with the air bag group 1-3-4, which is used to adjust the buoyancy of the front floating cavity 1-3 and the rear floating cavity 1-4 and the angle of floating on the water surface, and the mold front half 1-1 and the front floating cavity 1-3 are both provided with horizontal air bubbles 1-3-2, which are used to detect the levelness of the test bearing part loaded with the gravelly clay soil sample 2; in the embodiment, the number of horizontal air bubbles 1-3-2 is set to four, which are respectively arranged at the four corner positions of the combination structure of the front floating cavity 1-3 and the rear floating cavity 1-4, and before the test, the state of the horizontal air bubble 1-3-2 is observed to determine whether the test bearing part loaded with the gravelly clay soil sample 2 is level, and when the levelness is poor, the overall or local inflation of the air bag group is used to adjust the buoyancy and initial angle of the test bearing part loaded with the gravelly clay soil sample 2.

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

[0069] Further, in the above technical solution, the mold front half 1-1 and the mold rear half 1-2 both include a bearing 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, the middle parts of the lateral push plate 1-1-5 and the axial pull plate 1-1-6 are respectively provided with a lateral connecting hole 1-2-0 and an axial connecting hole 1-1-8, and the two ends of the side of the fixed bottom plate 1-1-7 away from the axial pull plate 1-1-6 are respectively provided with the first seam making plate 1-1-1 and the second seam making plate 1-1-2 which are axially symmetrically distributed, which are used to pre-make 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 installed with the fixed bottom plate 1-1-7;

[0070] The fixed bottom plate 1-1-7 is provided with notches at both ends of one side, and the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 are embedded in the notches at both sides, respectively, and the thicknesses of the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 are consistent with the depths of the notches, and a gap is reserved between the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 on the same fixed bottom plate 1-1-7, and the corresponding two groups of first seam forming plates 1-1-1 and second seam forming plates 1-1-2 on the front and rear fixed bottom plates 1-1-7 are mutually adhered.

[0071] In the embodiment, the thicknesses of the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 are 0.3 mm, that is, when the corresponding two groups of first seam forming plates 1-1-1 and second seam forming plates 1-1-2 on the front and rear fixed bottom plates 1-1-7 are mutually adhered, the thickness of the prefabricated seam formed is 0.6 mm.

[0072] Further, in the above technical solution, the Z-shaped compaction plate 1-7 is made of aluminum alloy, and the Z-shaped compaction plate 1-7 is provided with a plate gap 1-7-1 at both sides, and the plate gap 1-7-1 is adapted to the shape after the corresponding two groups of first seam forming plates 1-1-1 and second seam forming plates 1-1-2 on the front and rear fixed bottom plates 1-1-7 are mutually adhered;

[0073] The Z-shaped compaction plate 1-7 is adapted to the shapes of the mold front half 1-1 and the mold rear half 1-2, so that the Z-shaped compaction plate 1-7 is just clamped into the mold front half 1-1 and the mold rear half 1-2;

[0074] The Z-shaped compaction plate 1-7 is provided with a plate end handle 1-7-2 at the top, so as to facilitate taking down the Z-shaped compaction plate 1-7 after the gravel clay soil sample 2 is compacted.

[0075] Further, in the above technical solution, the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 are provided with positioning blocks 1-1-3 and combination blocks 1-1-4, respectively, wherein the combination blocks 1-1-4 are located at the lower sides of the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2, and the combination blocks 1-1-4 are connected with the fixed bottom plate 1-1-7 through bolts; the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 are selected according to the progress of the test whether to be removed. When the gravel clay soil sample 2 is made and the tensile fracture test is carried out, the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 do not need to be removed, and when the shear fracture test is carried out, the first seam forming plate 1-1-1 and the second seam forming plate 1-1-2 need to be removed.

[0076] The positioning block 1-1-3 is located in the middle of the side of the first seam plate 1-1-1 and the second seam plate 1-1-2, and the surface is provided with a hooking hole; when the shear rupture test is carried out, the first seam plate 1-1-1 and the second seam plate 1-1-2 need to be removed, and the combined block 1-1-4 is disconnected with the bearing box, and is used as a pulling point on the side to pull out from the gravel clay soil sample 2. The hooking hole provided on the positioning block 1-1-3 is hooked by the hooking tongs, and the positioning block 1-1-3 is pulled out to be disconnected.

[0077] The rectangular ring wall 1-6 is a rectangular ring-shaped aluminum alloy ring body, both sides of the bottom of which are provided with positioning grooves, and the positioning grooves are matched with the structure that the two groups of first seam plates 1-1-1 and second seam plates 1-1-2 on the front and rear two fixed bottom plates 1-1-7 are matched with each other, the inside of the rectangular ring wall 1-6 is matched with the outside of the test bearing part, and the top of the rectangular ring wall 1-6 is flush with the test bearing part after being sleeved on the outside of the test bearing part.

[0078] Further, in the above technical solution, the first threaded holes 1-1-9 are arranged on the three sides of the fixed bottom plate 1-1-7, and the top of the front floating cavity 1-3 and the rear floating cavity 1-4 is provided with a protruding part 1-3-3 matched with the three groups of first threaded holes 1-1-9, the bearing box is connected to the inside of the three groups of protruding parts 1-3-3, and is fixedly connected with the front floating cavity 1-3 or the rear floating cavity 1-4 through a bolt, the bolt penetrates the protruding part 1-3-3 and is screwed into the inside of the first threaded hole 1-1-9;

[0079] The second threaded holes 1-3-1 are arranged at both ends of the opposite side 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 through the cavity connecting plate 1-5 and the bolt, the cavity connecting plate 1-5 is an aluminum alloy connecting plate with holes, and the bolt penetrates the cavity connecting plate 1-5 and enters the inside of the second threaded hole 1-3-1 when the front floating cavity 1-3 and the rear floating cavity 1-4 are connected.

[0080] Further, in the above technical solution, the air bag group 1-3-4 includes a plurality of air bag bodies arranged in a rectangular array, which are 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] The plurality of air bag bodies are provided with a diaphragm, and the diaphragm is provided with a channel, and an electromagnetic valve is embedded in the channel, and each air bag body is provided with an independent inflation and deflation hole, so that the plurality of air bag bodies can be inflated and deflated synchronously or the amount of gas in the air bag bodies in the local area can be adjusted. Figure 5 As shown in (a), when not inflated, the lower surfaces of the plurality of air bag bodies are flush with the lower edges of the front floating cavity 1-3 and the rear floating cavity 1-4; as shown in (b), when inflated, the surfaces of the air bag bodies will be convex. Figure 5 As shown in (b), when inflated, the surfaces of the air bag bodies will be convex.Figure 5 (c) as shown, in addition to uniform inflation, the gas in the individual gas bag bodies in the gas 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, so as to adjust the angle of the front floating cavity 1-3 and the rear floating cavity 1-4 floating on the water surface, so that the two are horizontally floated on the water surface.

[0082] Further, in the above technical solution, the hollow test tank 7 is provided with water inlet holes 7-1 and water outlet holes 7-2 penetrating the recess, and the water inlet holes 7-1 and the water outlet holes 7-2 are used to supplement and replace the water in the recess, respectively.

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

[0084] The left propeller 3 comprises a left connecting part 3-1 and a left control part 3-2 for connecting and controlling the extension and contraction of the output end of the left connecting part 3-1;

[0085] The right propeller 4 comprises a right connecting part 4-1 and a right control part 4-2 for connecting and controlling the extension and contraction of the output end of the right connecting part 4-1;

[0086] The front puller 5 comprises a front connecting part 5-1 and a front control part 5-2 for connecting and controlling the extension and contraction of the output end of the front connecting part 5-1;

[0087] The rear puller 6 comprises a rear connecting part 6-1 and a rear control part 6-2 for connecting and controlling the extension and contraction of the output end of the rear connecting part 6-1;

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

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

[0090] Based on the above structure, the heights of 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 can be controlled, which facilitates the docking between the devices; and the two bearing boxes can be respectively subjected to a pushing force or a pulling force.

[0091] Further, 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 provided with a telescopic driving mechanism, which adopts at least one of a gas cylinder, an electric push rod, a hydraulic cylinder and a linear module.

[0092] Furthermore, in the above technical solution, displacement sensors and stress sensors are provided at the connecting ends of 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, respectively, to sense the displacement and stress value of 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 during the extension and retraction operation. Specifically, the collected data includes the displacement of the left connecting part 3-1 from left to right and the thrust it receives when the gravelly clay sample 2 is sheared and fractured, and the displacement of the right connecting part 4-1 from right to left and the thrust it receives; and the displacement of the front connecting part 5-1 from back to front and the tensile force it receives, and the displacement of the rear connecting part 6-1 from front to back and the tensile force it receives when the gravelly clay sample 2 is tensile and fractured.

[0093] The zero-friction tensile-shear fracture test device for gravelly clay core walls of high earth-rock dams provided by this invention is described in the following procedure: Figure 8 As shown, where:

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

[0095] Figure 8 (b) shows that Figure 8 Based on (a), the state of assembling and compacting fracture mold 1;

[0096] Figure 8 (c) shows that Figure 8 Based on (b), prepare and compact gravelly clay soil sample 2;

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

[0098] Figure 8 (e) shows that Figure 8 Based on (d), the state of removing Z-shaped compaction plates 1-7 and rectangular ring walls 1-6;

[0099] Figure 8 (f) shows that in Figure 8 Based on (e), the test support part (compact fracture mold test part) is suspended;

[0100] Figure 8 (g) shows that in Figure 8 Based on (f), the state of the fixed test bearing part (compaction fracture mold test part) is maintained;

[0101] Figure 8 (h) shows that in Figure 8(b) shows the state before the cavity connecting plate 1-5 is removed and the test is performed on the basis of (a);

[0102] Figure 8 (c) shows the state before the cavity connecting plate 1-5 is removed and the test is performed on the basis of (b); Figure 8 (d) shows the state before the cavity connecting plate 1-5 is removed and the test is performed on the basis of (c);

[0103] Figure 8 (e) shows the state before the cavity connecting plate 1-5 is removed and the test is performed on the basis of (d); Figure 8 (f) shows the state before the test bearing part (compacted fracture mold test part) is fixed on the basis of (e);

[0104] Figure 8 (g) shows the state before the cavity connecting plate 1-5 is removed and the test is performed on the basis of (f); Figure 8 (h) shows the state before the test bearing part (compacted fracture mold test part) is fixed on the basis of (g);

[0105] Figure 8 (i) shows the state before the test bearing part (compacted fracture mold test part) is fixed on the basis of (h); Figure 8 (j) shows the state before the cavity connecting plate 1-5 is removed and the test is performed on the basis of (i);

[0106] The present application gives the following examples:

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

[0108] S1, determining the optimum water content and the maximum dry density;

[0109] Specifically, before the fracture test is carried out, the optimum water content and the maximum dry density of the gravel-containing clay in the material yard near the dam site area of the high earth-rock dam under different gravel contents need to be determined. According to the specification, the gravel-containing clay is selected to carry out the compaction test by using a heavy compaction instrument, the mass of the compaction hammer is 4.5 kg, the diameter of the hammer bottom is 51 mm, and the drop height is 457 mm. The optimum water content and the maximum dry density of the gravel-containing clay in the high earth-rock dam site area under 30% to 50% gravel content. As shown in Table 1:

[0110] Table 1 Optimum water content and maximum dry density of gravel-containing clay under 30% to 50% gravel content

[0111]

[0112] S2, designing test conditions:

[0113] When studying the influence of water content on the fracture characteristics, five levels of 10.34%, 9.87%, 9.43%, 9.08%, and 8.72% are proposed for the test; when studying the influence of dry density on the fracture characteristics, 2.16 g / cm 3 , 2.14 g / cm 3 , 2.11 g / cm 3 , and 2.07 g / cm3 2.03 g / cm 3 Five levels of test were carried out; when the influence of gravel mixing amount on the fracture characteristics was studied, 30%, 35%, 40%, 45%, 50% five levels were designed for test; at the same time, other variables were controlled unchanged for test condition design.

[0114] S3. The mold half 1-1 and the mold half 1-2 are combined as shown in Figure 8 (a), and the specific operation is as follows:

[0115] S3.1. The mold half 1-1 is combined.

[0116] Specifically, the bolts are screwed into the combination blocks 1-1-4 and the fixed bottom plates 1-1-7 on the first seam forming plates 1-1-1 from left to right, so that the first seam forming plates 1-1-1 are relatively fixed on the bearing box; the bolts are screwed into the combination blocks 1-1-4 and the fixed bottom plates 1-1-7 on the second seam forming plates 1-1-2 from right to left, so that the second seam forming plates 1-1-2 are relatively fixed on the bearing box, and then the first seam forming plates 1-1-1, the second seam forming plates 1-1-2 and the bearing box are combined into the mold half 1-1.

[0117] S3.2. The mold half 1-2 is combined.

[0118] The same steps in S3.1 are used to combine another set of first seam forming plates 1-1-1, second seam forming plates 1-1-2 and bearing boxes into the mold half 1-2.

[0119] S4. The compacted fracture mold 1 is assembled as shown in Figure 8 (b), and the specific operation is as follows:

[0120] S4.1. The mold half 1-1 and the front floating cavity 1-3 are connected, and the mold half 1-2 and the rear floating cavity 1-4 are connected.

[0121] Specifically, the three sets of protrusions 1-3-3 are fixedly connected with the corresponding first threaded holes 1-1-9 by using bolts, so that the mold half 1-1 and the front floating cavity 1-3 are connected. The mold half 1-2 and the rear floating cavity 1-4 are connected by using the same method as described above.

[0122] S4.2. The front floating cavity 1-3 and the rear floating cavity 1-4 are connected, and the rectangular ring wall 1-6 is sleeved.

[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 machine oil is applied to the inside of the rectangular ring wall 1-6 to ensure sufficient lubrication when in contact with the compaction fracture mold test part. Then, the rectangular ring wall 1-6 is nested on the outside of the compaction fracture mold test part, so that the three are tightly combined into one, forming the compaction fracture mold 1.

[0124] S5, such as Figure 8 As shown in (c), gravelly clay soil sample 2 was prepared and compacted, and the specific procedures are as follows:

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

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

[0127] S5.3. The compaction fracture mold test section is added in N stages. After each addition of gravelly clay, the gravelly clay is compacted using Z-shaped compaction plates 1-7.

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

[0129] Specifically, the compacted gravelly clay sample 2, along with the compaction fracture mold 1, is placed into the hollow test chamber 7 using a hoisting rope. Since the hollow test chamber 7 is not filled with water, the compaction fracture mold 1 is in contact with the bottom of the hollow test chamber 7.

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

[0131] Specifically, the Z-shaped compaction plate 1-7 above the gravelly clay sample 2 and the rectangular ring wall 1-6 fitted on the outside of the front half 1-1 and the rear half 1-2 of the mold are removed, but the cavity connecting plate 1-5 is still connected to the front half 1-1 and the rear half 1-2 of the mold. At this time, the front half 1-1 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 section is suspended, and the specific operation is as follows:

[0133] S8.1, fill two groups of air bags 1-3-4 at the bottom of the front floating cavity 1-3 and the rear floating cavity 1-4 with a certain amount of hydrogen, so that the front floating cavity 1-3 and the rear floating cavity 1-4 are lifted up due to the protrusion of the air bag group 1-3-4;

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

[0135] S8.3, adjust the floating condition of the compacted fracture mold test part by changing the hydrogen content in the air bag body at different positions in the front floating cavity 1-3 and the rear floating cavity 1-4, and adjust the level of the compacted fracture mold 1 by means of the four horizontal air bubbles 1-3-2 on the front floating cavity 1-3 and the rear floating cavity 1-4.

[0136] Further, in the above technical solution, the hydrogen filling amount of the two groups of air bag groups 1-3-4 is calculated as follows:

[0137] S8.1.1, collect the mass A of the compacted fracture mold test part and the mass Y of the gravel clay soil sample 2 to obtain the total mass A+Y of the test main body composed of the compacted fracture mold test part and the gravel clay soil sample 2;

[0138] S8.1.1, by substituting A+Y into the following expression, the corresponding buoyancy F(floating) is solved;

[0139] A+Y=F(floating)=G(displacement)=p(water)gV(displacement)

[0140] Where, p(water) represents the density of the liquid filled in the hollow test tank 7, g is the acceleration of gravity, and the value is 9.8 m / s 2 , V(displacement) represents the volume of the test main body displaced by the liquid, and G(displacement) represents the displacement of the test main body floating on the water surface against gravity;

[0141] It is concluded that:

[0142] V(displacement)=(A+Y) / p(water)g

[0143] S8.1.2, by substituting the volume V(displacement) of the test main body displaced by the liquid when floating into the following formula, the mass M of hydrogen at least required to be filled to realize the floating of the test main body against gravity is calculated;

[0144] M=p(gas)V(displacement)

[0145] Where, p(gas) represents the density of hydrogen, and the value is 0.089 g / m 3 .

[0146] Further, in the above technical solution, the leveling mode described in S8.3 is realized based on the structure of the air bag group, which includes a plurality of air bag bodies distributed in a rectangular array, for filling hydrogen;

[0147] A diaphragm is arranged between the plurality of air bag bodies, and a channel is arranged on the diaphragm, and an electromagnetic valve is embedded in the channel, and an independent inflation and deflation hole is arranged on each air bag body, so that the plurality of air bag bodies can be inflated and deflated synchronously or the amount of gas in the air bag bodies in the local area can be adjusted;

[0148] The connection end of the electromagnetic valve is electrically connected to a remote control chip, and the number of the specific air bag body is input through the remote controller to add or subtract the hydrogen filled therein.

[0149] Further, in the above technical solution, when the two groups of air bag groups 1-3-4 are inflated, the following situations exist:

[0150] When the up-and-down position of the test body on the water surface is fine-tuned, a plurality of electromagnetic valves are opened, the plurality of air bag bodies are communicated, the hydrogen mass P in any one air bag body is increased, the hydrogen in the other air bag bodies is correspondingly supplemented, and the overall height of the test body on the water surface is adjusted up and down.

[0151] When the electromagnetic valve between one air bag body and the adjacent air bag body is not opened due to signal control or failure, causing the one air bag body to be recessed relative to the outside, the electromagnetic valve on the one air bag body is controlled to be opened, and the hydrogen mass in each of the other air bag bodies is correspondingly reduced by P / (n-1), where n is the number of air bag bodies in each group of air bag groups 1-3-4. In this embodiment, both groups of air bag groups 1-3-4 contain 32 air bag bodies, and when the compacted fracture mold 1 needs to be leveled, the hydrogen mass P of a certain air bag is increased, and the hydrogen mass in each of the other air bag bodies is correspondingly reduced by P / 31.

[0152] When the test body is tilted and needs to be leveled, the electromagnetic valve is closed, the hydrogen mass P of a certain air bag body in the lower side region of the compacted fracture mold 1 is increased, and the increased hydrogen mass P is charged into the corresponding air bag body from the external gas supply pipe.

[0153] At this point, the whole core wall gravel clay tensile-shear fracture test device is assembled;

[0154] S9, complete the assembly of the test device, and select the test type:

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

[0156] S9.1, carry out the tensile fracture test of the core wall gravel clay:

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

[0158] S9.1.1、as shown in Figure 8 (g) shown, fixed compaction fracture mold test part:

[0159] By controlling the front side control part 5-2, the rear side control part 6-2 respectively, the front side connecting part 5-1, the rear side connecting part 6-1 output end elongation, gradually close to the front axial connection hole 1-1-8 and the rear side connection hole 1-2-0, fine adjustment of the two groups of air bag group 1-3-4 inside the hydrogen content, make the axial connection hole 1-1-8 and the side connection hole 1-2-0 respectively with the front side connecting part 5-1, the rear side connecting part 6-1 height consistent, and again elongation of the front side connecting part 5-1, the rear side connecting part 6-1, until the fixed connection with the compaction fracture mold test part;

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

[0161] The connecting front floating cavity 1-3 and the rear floating cavity 1-4 and the cavity connecting plate 1-5 on both sides are removed, and the front side control part 5-2 and the rear side control part 6-2 are opened, and the front side connecting part 5-1 and the rear side connecting part 6-1 are pulled at a certain rate; record the stress and displacement sensor data measured by the front side connecting part 5-1 and the rear side connecting part 6-1;

[0162] S9.1.3、as shown in Figure 8 (i) shown, until the stretch fracture of the gravel clay soil sample 2 and process data:

[0163] Record the stress and displacement until the stretch fracture of the gravel clay soil sample 2, and then process the stress and displacement data to obtain the stress F(tension) and displacement L(tension) of the gravel clay soil sample 2 in the stretch fracture test, which is expressed as follows:

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

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

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

[0167] According to the value of F(tension) and L(tension), the stress-strain curve of the stretch fracture of the gravel clay soil sample 2 is obtained; the characteristic parameters of the stretch fracture process of the high earth-rock dam gravel clay are analyzed through the stretch fracture stress-strain curve, including the fracture toughness and the fracture energy; so as to fully understand the stretch fracture characteristics of the high earth-rock dam gravel clay soil sample 2.

[0168] Further, 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 for studying the influence of different loading rates on the tensile fracture characteristics of the gravel mixed clay soil sample 2; for example, multiple gears are set to 1 gear (0.005 mm / s), 2 gears (0.01 mm / s), 3 gears (0.02 mm / s), 4 gears (0.05 mm / s), and 5 gears (0.1 mm / s), 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 period and the operation period. Due to the high core wall, the uneven settlement of the gravel mixed clay at the low part of the core wall is small, and 1 gear or 2 gears can be used for testing; the uneven settlement of the gravel mixed clay at the high part of the core wall is large, and 4 gears or 5 gears can be used for testing.

[0169] It should be noted that when the front connecting part 5-1 and the rear connecting part 6-1 are respectively set to 1 gear (0.005 mm / s), they are pulled simultaneously, that is, the loading rate for studying the tensile fracture characteristics of the gravel mixed clay is 0.01 mm / s. The same applies to other gears.

[0170] S9.2, carry out shear fracture test of core wall gravel mixed clay:

[0171] 2. The shear fracture test operation process of the gravel mixed clay soil sample 2 is as follows:

[0172] S9.2.1, as shown in Figure 8 (j), fix the compaction fracture mold test part:

[0173] By controlling the left control part 3-2 and the right control part 4-2, the left connecting part 3-1 and the right control part 4-2 are gradually elongated to closely approach the left axial connecting hole 1-1-8 and the right lateral connecting hole 1-2-0, and the hydrogen content in the two groups of air bags 1-3-4 is adjusted to make the axial connecting hole 1-1-8 and the lateral connecting hole 1-2-0 consistent with the left connecting part 3-1 and the right connecting part 4-1 in height, and then the left connecting part 3-1 and the right connecting part 4-1 are elongated again until they are fixedly connected with the compaction fracture mold test part;

[0174] S9.2.2, as shown in Figure 8 (k), remove the cavity connecting plate 1-5, expose the prefabricated joint, and perform the test:

[0175] Remove the cavity connecting plates 1-5 that connect the front floating cavity 1-3 and the rear floating cavity 1-4 and are located on their left and right sides. With the assembly block 1-1-4 disconnected from the carrier box, simultaneously use hook pliers to hook into the hook holes on the positioning blocks 1-1-3 on both sides, and remove the first seam plate 1-1-1 and the second seam plate 1-1-2 respectively. Open the left control unit 3-2 and the right control unit 4-2, and advance the left connecting part 3-1 and the right connecting part 4-1 at a certain rate. Record the stress and displacement sensor data inside the left connecting part 3-1 and the right connecting part 4-1.

[0176] S9.2.3, such as Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure 8 Figure As shown in (l), until the gravelly clay sample 2 underwent shear fracture and the data was processed:

[0177] The stress and displacement were recorded until the gravelly clay sample 2 underwent shear fracture. The stress and displacement data were then processed to obtain the stress F (shear) and displacement L (shear) experienced by the gravelly clay sample 2 during the shear fracture test, expressed as follows:

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

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

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

[0181] Based on the F (shear) and L (shear) values, the stress-strain curve of the gravelly clay sample 2 under shear fracture was obtained. The characteristic parameters of the gravelly clay in the high earth-rock dam under shear fracture process were analyzed by the stress-strain curve of shear fracture. The characteristic parameters include fracture toughness and fracture energy. Thus, the shear fracture characteristics of the gravelly clay sample 2 of the high earth-rock dam were fully understood.

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

[0183] It should be noted that when the left connecting part 3-1 and the right connecting part 4-1 are respectively in gear 1 (0.005 mm / s), the loading rate affecting the shear fracture characteristics of the gravel-mixed clay studied is 0.01 mm / s because the front and rear are simultaneously pushed. The same applies to other gears.

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

Claims

1. A zero-friction tensile-shear fracture testing device for high earth-rockfill dam core mixed-gravel clay, characterized in that: The utility model relates to a kind of test devices for the shear and tensile test of gravelly clay, including compaction fracture mould (1) and hollow test tank (7), wherein compaction fracture mould (1) is used to make gravelly clay soil sample (2), which includes test bearing part and rectangular ring wall (1-6) and Z-shaped compaction plate (1-7), the hollow test tank (7) is provided with rectangular recess in the top center position, and water body capable of making test bearing part of gravelly clay soil sample (2) float is filled in the recess; The prepared gravelly clay soil sample (2) has soil sample fracture section (2-1), and both sides are respectively set as soil sample front end (2-2) and soil sample rear end (2-3); The test bearing part includes mould front half (1-1), mould rear half (1-2), front floating cavity (1-3), rear floating cavity (1-4) and cavity connecting plate (1-5), wherein mould front half (1-1) and mould rear half (1-2) are detachably installed on front floating cavity (1-3) and rear floating cavity (1-4) respectively, and front floating cavity (1-3) and rear floating cavity (1-4) are detachably connected through cavity connecting plate (1-5); The combination structure of mould front half (1-1) and front floating cavity (1-3) and the combination structure of mould rear half (1-2) and rear floating cavity (1-4) are the same, and the two combination structures are centrally symmetrically distributed, the bottom of front floating cavity (1-3) and rear floating cavity (1-4) is opened and embedded with air bag group (1-3-4), for adjusting the buoyancy of front floating cavity (1-3) and rear floating cavity (1-4) and the angle of floating on water surface, and horizontal air bubble (1-3-2) is arranged on mould front half (1-1) and front floating cavity (1-3), for detecting the levelness of test bearing part loaded with gravelly clay soil sample (2); The left and right sides of the hollow test tank (7) are respectively provided with left propeller (3) and right propeller (4) which are centrally symmetrically distributed, left propeller (3) and right propeller (4) respectively propel mould front half (1-1) and mould rear half (1-2) to the center of test device, for applying shear force to gravelly clay soil sample (2);The front and rear sides of the hollow test tank (7) are respectively provided with front puller (5) and rear puller (6) which are axially symmetrically distributed, front puller (5) and rear puller (6) respectively pull mould front half (1-1) and mould rear half (1-2) to the front and rear sides of test device, for applying tensile force to gravelly clay soil sample (2).

2. The zero friction tensile-shear split -tension test device for high earth-rockfill dam core wall mixed clay with gravel according to claim 1, characterized in that: The mold front half (1-1) and the mold rear half (1-2) both comprise a bearing 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 vertically fixed on the adjacent side walls of the fixed bottom plate (1-1-7) respectively, the middle part of the lateral push plate (1-1-5) and the axial pull plate (1-1-6) is respectively provided with a lateral connecting hole (1-2-0) and an axial connecting hole (1-1-8), and the side of the fixed bottom plate (1-1-7) away from the axial pull plate (1-1-6) 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 respectively, for pre-making 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 detachably installed with the fixed bottom plate (1-1-7); The side of the fixed bottom plate (1-1-7) is provided with notches at both ends, the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) are embedded in the notches at both sides respectively, and the thickness of the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) is consistent with the depth of the notches, and 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 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 bottom plates (1-1-7) are mutually adhered.

3. The zero friction tensile-shear split -tension test device for high earth-rockfill dam core wall mixed clay with gravel according to claim 1, characterized in that: The Z-shaped compaction plate (1-7) is made of aluminum alloy, and the two sides are provided with plate middle gaps (1-7-1), and the plate middle gaps (1-7-1) are adapted to the shape after the corresponding two groups of first seam-making plates (1-1-1) and second seam-making plates (1-2-1) on the front and rear fixed bottom plates (1-1-7) are mutually adhered; The Z-shaped compaction plate (1-7) is adapted to the shape of the mold front half (1-1) and the mold rear half (1-2); The Z-shaped compaction plate (1-7) is provided with a plate end handle (1-7-2) at the top.

4. The zero friction tensile-shear split -tension test device for high earth rockfill dam core wall mixed clay with gravel according to claim 2, characterized in that: The first seam-making plate (1-1-1) and the second seam-making plate (1-1-2) are both provided with a positioning block (1-1-3) and a combination block (1-1-4), wherein the combination block (1-1-4) is located on the side surface of the lower part of the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2), and is connected and combined with the fixed bottom plate (1-1-7) through bolts; The positioning block (1-1-3) is located in the middle part of the side surface of the first seam-making plate (1-1-1) and the second seam-making plate (1-1-2), and a hook pulling hole penetrates the surface thereof; The rectangular ring wall (1-6) adopts a rectangular ring-shaped aluminum alloy ring body, both sides of which are provided with positioning grooves, and the positioning grooves are matched with the structure that the two groups of first and second seam forming plates (1-1-1 and 1-1-2) on the front and rear fixed bottom plates (1-1-7) are matched with each other, the inside of the rectangular ring wall (1-6) is matched with the outside of the test bearing part, and the top of the rectangular ring wall (1-6) is flush with the test bearing part after being sleeved on the outside of the test bearing part.

5. The zero friction tensile-shear split -tension test device for high earth rockfill dam core wall mixed clay with gravel according to claim 2, characterized in that: The three sides of the fixed bottom plate (1-1-7) are provided with first threaded holes (1-1-9), and the top of the front floating cavity (1-3) and the rear floating cavity (1-4) is provided with a protruding part (1-3-3) matched with the three groups of first threaded holes (1-1-9), the bearing box is clamped on the inside of the three groups of protruding parts (1-3-3) and is fixedly connected with the front floating cavity (1-3) or the rear floating cavity (1-4) through bolts; The opposite sides of the front floating cavity (1-3) and the rear floating cavity (1-4) are provided with second threaded holes (1-3-1) at both ends, and the front floating cavity (1-3) or the rear floating cavity (1-4) is fixedly connected through the cavity connecting plate (1-5) and the bolts.

6. The zero friction, high earth dam core wall, gravel admixture, clay, tensile-shear, split test device, according to claim 1, wherein: The air bag group (1-3-4) includes a plurality of air bag bodies arranged in a rectangular array, which are made of rubber material and filled with hydrogen gas; A plurality of diaphragms are arranged between the air bag bodies, and a channel is arranged on the diaphragm, and an electromagnetic valve is embedded in the channel, and an independent air charging and discharging hole is arranged on each air bag body, so that the plurality of air bag bodies can be synchronously charged and discharged or the amount of gas in the air bag bodies in the local area can be adjusted.

7. The zero friction, high earth dam core wall, gravel admixture, clay tensile- shear fracture testing device, according to claim 1, characterized by: The outer wall of the hollow test tank (7) is provided with water inlet holes (7-1) and water outlet holes (7-2) penetrating the recess, and the water inlet holes (7-1) and the water outlet holes (7-2) are used for supplementing and replacing the water in the recess, respectively.

8. The zero friction, high earth dam core wall, gravel admixture, clay tensile- shear fracture testing device, according to claim 1, characterized by: The left propeller (3), the right propeller (4), the front puller (5) and the rear puller (6) are installed on the hollow test tank (7) through the lifting mechanism; The left propeller (3) includes a left connecting part (3-1) and a left control part (3-2) for connecting and controlling the extension and contraction of the output end of the left connecting part (3-1); The right propeller (4) includes a right connecting part (4-1) and a right control part (4-2) for connecting and controlling the extension and contraction of the output end of the right connecting part (4-1); The front puller (5) includes a front connecting part (5-1) and a front control part (5-2) for connecting and controlling the extension and contraction of the output end of the front connecting part (5-1); The rear puller (6) includes a rear connecting part (6-1) and a rear control part (6-2) for connecting and controlling the extension and contraction of the output end of the rear connecting part (6-1); The output ends of the left connecting part (3-1) and the right connecting part (4-1) are respectively connected to the lateral connecting holes (1-2-0) on the two bearing boxes; The output ends of the front connecting part (5-1) and the rear connecting part (6-1) are respectively connected to the axial connecting holes (1-1-8) on the two bearing boxes.

9. The zero friction, high earth dam core wall, gravel admixture, clay tensile-shear fracture testing device, according to claim 8, wherein: 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 provided as telescopic driving mechanisms, which adopt at least one of a pneumatic cylinder, an electric push rod, a hydraulic cylinder and a linear module.

10. The zero friction, high earth dam core wall, gravel admixture, clay tensile- shear fracture testing device, according to claim 8, wherein: The connecting ends of 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 provided with displacement sensors and stress sensors, which are used for sensing the displacement and stress values of 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) during telescopic operation, respectively.

Images