Complex maintenance device for soil and structure contact surface test

Abstract

The utility model discloses a complex maintenance device for soil and structure contact surface test, which comprises an upper maintenance structure, a lower maintenance structure and an interface contact system, the lower end of the upper maintenance structure is provided with a first test cavity, and the upper end of the lower maintenance structure is provided with a second test cavity; the upper maintenance structure can cover the upper end of the lower maintenance structure; the interface contact system comprises a pressure plate, a magnetic counterforce shifter and a power supply, the second test cavity is provided with the pressure plate, the lower maintenance structure is provided with the magnetic counterforce shifter, the magnetic counterforce shifter abuts against the lower end of the upper maintenance structure, and the magnetic counterforce shifter, the pressure plate and the power supply are electrically connected. According to the utility model, when the sample soil body is subjected to expansion or contraction state change, the pressure plate is used for correspondingly changing the magnitude of current according to the pressure change, so that the magnetic counter-force displacer is promoted to generate coordinated deformation consistent with the expansion amount of the soil body, and the maintenance structure and the sample soil body are subjected to coordinated synchronous deformation; and the reduction precision of test simulation is improved.

Description

Technical Field

[0001] The utility model relates to a test maintenance device, in particular to a composite maintenance device used for soil and structure contact surface testing. Background Art

[0002] Geobags are an excellent way to reinforce slopes because of their low cost, ease of operation and strong self-sustainability. When a slope protection structure built with geobags is subjected to the soil pressure of the slope, the friction between the geobag-soil interface and the geobag-geobag interface can suppress the displacement of the slope and prevent the slope from collapsing and sliding. Therefore, the interface shear strength of geobags under different contact media is a key factor that should be considered in the design of slope protection structures.

[0003] In recent years, with the continuous exploration and research of geobag technology, it has been found that geobag structure has a significant effect on slowing down temperature transfer and inhibiting soil frost heave. Therefore, it has been applied to the slope protection projects of river ditches in some areas in northern my country. At the same time, most parts of my country have a monsoon climate, and short-term heavy rainfall often occurs frequently in summer. At this time, geobags are widely used in the reinforcement projects of slopes, river embankments, etc. Existing studies have shown that frequent dry-wet cycles will affect the reinforcement efficiency of geobags. At present, the upper and lower contact bodies are generally used for the maintenance of interface contact assembly samples under complex conditions. After the maintenance is completed, the joint shear is performed, and then the interface shear characteristics are studied. However, this method ignores the influence of soil frost heave and thaw shrinkage. At the same time, for soils with high mineral content such as expansive soil and clay, this maintenance method ignores the changes in the bag-soil contact interface during the dry-wet cycle. Human factors have a greater impact on the sample, and there is a large difference between the test results and the actual state.

[0004] Currently, there is still a lack of maintenance structures for interface contact assemblies under freeze-thaw cycles that can take into account the phenomena of frost heave and thaw shrinkage. There is an existing maintenance-dry-wet cycle integrated machine, which can effectively reduce the impact of human factors on the dry-wet cycle process of conventional soils. Although the pulling assembly can be simulated by the layered compaction method, it is difficult to simulate and restore the state of the interface contact assembly. At the same time, when the soil is a special soil such as expansive soil, due to spatial constraints, the expansion and contraction behavior of the soil itself during the dry-wet cycle cannot be considered, and there is a large difference between the soil structure after the cycle and the actual state.

[0005] Therefore, there is an urgent need for a composite curing device for soil-structure contact surface testing to solve the problem of coordinated and synchronous deformation of the curing structure and the sample soil. Utility Model Content

[0006] The utility model aims at the deficiencies in the prior art and provides a composite curing device for soil and structure contact surface test to solve the problem of coordinated and synchronous deformation of the curing structure and the sample soil body.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] A composite maintenance device for testing the contact surface between soil and structure, characterized in that it includes an upper maintenance structure, a lower maintenance structure and an interface contact system, the lower end of the upper maintenance structure is provided with a first test cavity, the upper end of the lower maintenance structure is provided with a second test cavity, the upper maintenance structure can be covered on the upper end of the lower maintenance structure, and the first test cavity is connected to the second test cavity; the interface contact system includes a pressure plate, a magnetic reaction force displacer and a power supply, the inner side of the second test cavity is provided with a pressure plate, the upper end of the edge of the lower maintenance structure is provided with a magnetic reaction force displacer, the upper end of the magnetic reaction force displacer is used to abut against the edge of the lower end of the upper maintenance structure, and the magnetic reaction force displacer, the pressure plate and the power supply are electrically connected to each other.

[0009] To optimize the above technical solutions, the specific measures taken also include:

[0010] Furthermore, the magnetic reaction force displacer includes an electromagnetic coil, an iron core and a metal displacement block. Several iron cores are vertically installed at the upper end of the edge of the lower maintenance structure, and electromagnetic coils are respectively wound around the outside of the iron cores. A metal displacement block is provided at the upper end of the iron core, and the upper end of the metal displacement block is used to contact the lower end surface of the upper maintenance structure. The electromagnetic coil is connected in series with the pressure plate, and the electromagnetic coil and the pressure plate are connected to a power supply through a wire.

[0011] Furthermore, the pressure plate adopts a resistive pressure sensor.

[0012] Furthermore, the upper end of the lower maintenance structure is provided with a circle of outward-extending flanges, and the edge of the lower maintenance structure and the upper end of the flange are jointly provided with a groove for the lower end of the upper maintenance structure to be inserted, and the inner wall of the groove is provided with a sealing strip, and the magnetic reaction force displacer is arranged in the groove and located on the inner side of the sealing strip.

[0013] Furthermore, a freeze-thaw system is provided in the upper maintenance structure, and the freeze-thaw system includes heating wires and dividing blocks. A cavity is opened in the side wall of the upper maintenance structure, and a plurality of dividing blocks are installed at intervals on the outer side of the cavity, and a plurality of groups of heating wires are installed at intervals on the inner side of the cavity, and each group of the heating wires is located between two dividing blocks. The cavity is formed by the heating wires and the dividing blocks to form a circulating liquid path with a serpentine side cross-section, and a circulation port connected to the circulating liquid path is provided at the top of the upper maintenance structure, and the circulation port can be used for liquid circulation of external equipment.

[0014] Furthermore, a temperature insulation layer is provided between the heating wire and the circulating liquid path, and the temperature insulation layer is wrapped around the outside of the heating wire.

[0015] Furthermore, it also includes a dry-wet system, which includes an upper permeable electro-osmotic plate, a lower permeable electro-osmotic plate, a water storage tank and a water supply layer. The side wall of the lower maintenance structure is a lower supporting wall, and a water storage tank is opened in the bottom of the lower supporting wall. The bottom end of the second test cavity is set as a water supply layer connected to the water storage tank, and the upper end of the water supply layer is installed with a lower permeable electro-osmotic plate, which covers the bottom of the second test cavity, and the upper permeable electro-osmotic plate is installed to cover the top of the first test cavity.

[0016] Furthermore, a through hole connecting the water storage tank with the water supply layer is provided on the lower supporting wall.

[0017] Furthermore, a plurality of limiting feet for supporting the lower water-permeable electro-osmotic plate are installed on the inner side wall of the lower supporting wall located at the lower end of the lower water-permeable electro-osmotic plate.

[0018] Furthermore, it also includes a geobag constraint frame and a geotextile. A vertical geobag constraint groove is opened in the middle of the lower edge of the upper maintenance structure. The geotextile can be laid between the first test cavity and the second test cavity. The geobag constraint frame is used to clamp the edge of the geotextile, and the geobag constraint frame is provided with an end that can be inserted into the geobag constraint groove; the lower end edge of the upper maintenance structure is located on the outside of the geobag constraint groove as an upper support wall, and the upper support wall is used to abut against the upper end face of the magnetic reaction force displacer.

[0019] The beneficial effects of the utility model are:

[0020] 1. The complex environment interface contact assembly maintenance structure that can coordinate deformation proposed by the utility model can realize high-precision simulation and restoration of the actual contact state of the interface contact assembly, avoiding the disadvantage that the traditional interface contact assembly can only be maintained separately during dry-wet cycle and freeze-thaw cycle tests, and greatly avoids the disturbance of the sample during the maintenance process, ensuring the scientific reliability of the test process and the accuracy of the test data, and effectively reducing the test error.

[0021] 2. The freeze-thaw system and dry-wet system proposed in the utility model can effectively simulate the working conditions of the interface contact assembly under complex conditions such as freeze-thaw, dry-wet and so on. Compared with other maintenance structures, the utility model can realize orthogonal simulation of multiple states through the same structure, and there is no need for frequent and multiple migrations during the maintenance process, which effectively reduces the interference of external environmental conditions and other factors on subsequent test data, and realizes efficient and accurate acquisition of test data.

[0022] 3. The interface contact system proposed in the utility model can effectively realize the close contact of all parts of the interface contact assembly, avoid the influence of the interface segmentation phenomenon caused by the traditional separate structure on the subsequent test data, and rely on the pressure plate and the magnetic reaction force displacement device structure to effectively realize the coordinated and synchronous deformation of the maintenance structure and the sample soil. It innovatively solves the problem of uncoordinated deformation of the sample and the structure in the traditional maintenance structure, avoids the structural damage to the contact interface of the sample soil caused by this, and also effectively avoids the misaligned overlap phenomenon in the subsequent interface shear test, ensuring the scientific nature of the maintenance process and the accuracy of the data obtained from the subsequent tests.

[0023] 4. The supporting wall sealing system proposed in the utility model can provide sufficient supporting efficiency for the overall maintenance structure. At the same time, it relies on the sealing strip with a free upper end and a fixed lower end to ensure the coordinated deformation of the sample soil and the maintenance structure, while realizing the sealing of the overlapping parts of the maintenance structure, avoiding the occurrence of differences in the circulating moisture content of the sample soil caused by water leakage during the dry-wet cycle and freeze-thaw cycle, and further ensuring the scientificity and rigor of the sample maintenance process. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a partial cross-sectional structural schematic diagram of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0025] Figure 2 This is a schematic cross-sectional structure diagram of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0026] Figure 3 A schematic diagram of the partial structure of a freeze-thaw system of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0027] Figure 4 This is an enlarged view of the partial structure of the freeze-thaw system of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0028] Figure 5 It is a partial installation schematic diagram of a geobag restraint frame of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0029] Figure 6 This is a schematic structural diagram of a magnetic reaction force displacement device of a composite body maintenance device for soil and structure contact surface testing proposed by the utility model;

[0030] Figure 7 This is a schematic diagram of the structure of a geobag restraint trough of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0031] Figure 8 This is a schematic diagram of the structure of a sealing strip of a composite curing device for soil-structure contact surface testing proposed by the utility model;

[0032] Fig. 9 The utility model provides a schematic diagram of the local structure of the dry-wet system of the composite curing device for soil-structure contact surface testing.

[0033] Figure numerals: 1-sample soil; 2-freeze-thaw system; 21-heating wire; 22-circulating liquid circuit; 23-thermal insulation layer; 24-circulation port; 3-interface contact system; 31-geobag constraint frame; 32-geotextile; 33-geobag constraint groove; 34-pressure plate; 35-magnetic reaction force displacer; 351-electromagnetic coil; 352-iron core; 353-metal displacement block; 36-wire; 37-power supply; 4-support wall sealing system; 41-upper support wall; 42-sealing strip; 43-lower support wall; 5-dry-wet system; 51-lower permeable electro-osmotic plate; 52-limiting foot; 53-water storage tank; 54-water supply layer; 55-upper permeable electro-osmotic plate. DETAILED DESCRIPTION

[0034] The utility model is described in detail below with reference to the accompanying drawings.

[0035] As attached Figure 1 , Attachment Figure 2 and attached Figure 5 As shown, a composite maintenance device for soil-structure contact surface test according to an embodiment of the utility model comprises an upper maintenance structure, a lower maintenance structure and an interface contact system 3, a first test cavity is provided at the lower end of the upper maintenance structure, a second test cavity is provided at the upper end of the lower maintenance structure, the upper maintenance structure can be covered on the upper end of the lower maintenance structure, the first test cavity is connected to the second test cavity, and the first test cavity and the second test cavity are used to hold a sample soil body 1; the interface contact system 3 comprises a pressure plate 34, a magnetic reaction force displacement A device 35 and a power supply 37, a pressure plate 34 is provided on the inner wall of the second test cavity, one end of the pressure plate 34 is used to abut the sample soil 1, and a power supply 37 is also provided between the other end of the pressure plate 34 and the inner wall of the second test cavity, a magnetic reaction force displacer 35 is provided at the position where the upper end of the edge of the second test cavity of the lower maintenance structure is connected to the upper maintenance structure, and the upper end of the magnetic reaction force displacer 35 is used to abut against the edge of the lower end of the upper maintenance structure, and the magnetic reaction force displacer 35, the pressure plate 34 and the power supply 37 are electrically connected to each other.

[0036] The utility model loads the sample soil 1 into the second test cavity and the first test cavity provided with the pressure plate 34, and then supports the connection between the upper maintenance structure and the lower maintenance structure through the magnetic reaction force displacer 35, and electrically connects the magnetic reaction force displacer 35, the pressure plate 34 and the power supply 37 to each other, so that when the required freeze-thaw or dry-wet test is carried out, the sample soil 1 will produce a state change of expansion or contraction due to different changes. At this time, the pressure plate 34 in the interface contact system 3 is used to sense the pressure change from the sample soil 1, and the current in the circuit is changed according to the pressure change, so as to prompt the magnetic reaction force displacer 35 to produce a coordinated deformation amount consistent with the soil expansion amount, so that the upper maintenance structure and the lower maintenance structure are synchronously deformed, that is, the coordinated and synchronous deformation of the maintenance structure and the sample soil 1 is achieved, the accuracy of the maintenance test structure of the sample soil 1 is guaranteed, the restoration accuracy of the test simulation is improved, and the influence on the physical and mechanical properties of the sample contact interface due to the inability to coordinate deformation is effectively avoided, and the accuracy and effectiveness of the test results are guaranteed.

[0037] In this embodiment, the pressure plate 34 can be arranged on the inner side walls of the upper and lower maintenance structures as required, and is surrounded on all sides.

[0038] As attached Figure 6 As shown, in another embodiment, the magnetic reaction force displacer 35 includes an electromagnetic coil 351, an iron core 352 and a metal displacement block 353. The upper end of the edge of the lower maintenance structure is used to vertically install several iron cores 352 at the connection with the upper maintenance structure. The electromagnetic coils 351 are respectively wound around the iron cores 352. The upper end of the iron core 352 is provided with a metal displacement block 353. The upper end of the metal displacement block 353 is used to resist the lower end surface of the upper maintenance structure. The lower end of the metal displacement block 353 has a fixed magnetism that is the same as the magnetism formed by the electromagnetic coil 351 and the iron core 352. The electromagnetic coil 351 is connected in series with the pressure plate 34, and the electromagnetic coil 351 and the pressure plate 34 are connected to the power supply 37 through the wire 36.

[0039] Among them, the pressure plate 34 can adopt a resistive pressure sensor. The electromagnetic coil 351 is a multi-turn electromagnetic coil, which is wound around the iron core 352 as the center. The electromagnetic coil 351 is connected to the power supply 37 through a wire. When the electromagnetic coil 351 and the iron core 352 need to work together to generate magnetism, power is supplied. The iron core 352 in the magnetic reaction force displacer is located at the center of the electromagnetic coil 351, and its cross-section is slightly smaller than the open end area of ​​the upper and lower structure support walls, and the width of the left area is consistent with the width of the multi-turn electromagnetic coil. The metal displacement block 353 in the magnetic reaction force displacer 35 is located at the upper part of the overall structure, which is an inverted convex structure, and its cross-sectional size is consistent with the open end area of ​​the upper and lower structure support walls. The lower part of the metal displacement block 353 is a fixed-pole permanent magnet structure, and the side wall of the metal displacement block 353 is in low-friction contact with the surrounding side wall, which can achieve low-resistance up and down sliding over a certain distance.

[0040] Thus, when in use, the pressure plate 34 senses the different pressures fed back by the sample soil 1 to adjust its own resistance, thereby controlling the magnitude of the current in the circuit; correspondingly, when the internal resistance of the pressure plate 34 decreases, the current in the path increases, and the magnetic reaction force displacer 35 is located at the port of the upper maintenance structure and the lower maintenance structure. Because the lower part of the metal displacement block 353 has fixed magnetism, and the magnetism formed by the electromagnetic coil 351 and the iron core 352 is the same, according to the principle of mutual repulsion of like poles, the pressure plate 34 regulates the magnetic force generated by the electromagnetic coil 351 and the iron core 352 by changing the current, thereby changing the magnitude of the repulsive force formed with the like-pole magnet at the lower part of the metal displacement block 353, thereby achieving coordinated deformation between the sample soil 1 and the interface contact system 3. In this embodiment, devices such as the power supply 37 can be connected to external devices as needed.

[0041] The magnetic reaction force displacement device 35 uses the soil modulus and other soil physical and mechanical parameters of the sample soil, and replaces the internal metal displacement block 353 to achieve coordinated matching of the structure with the displacement of soils of different properties, effectively ensuring the synchronization and consistency of the deformation of the maintenance structure and the deformation of the soil, avoiding the misalignment and overlap of the contact interface during the shearing process caused by excessive deformation of the maintenance structure and the damage to the interface soil structure caused by excessive soil deformation, avoiding the influence of the above-mentioned problems on the test results, and effectively improving the scientific nature of the test and the accuracy of the test data.

[0042] As attached Figure 8 As shown, in another embodiment, it also includes a support wall sealing system 4, the support wall sealing system 4 includes a sealing strip 42, the upper end of the lower maintenance structure is provided with a circle of outwardly extending flange, the outer diameter of the lower end of the upper maintenance structure is smaller than the outer diameter of the flange, the edge of the lower maintenance structure and the upper end of the flange are jointly provided with a groove for the lower end of the upper maintenance structure to be inserted, the inner wall of the groove is provided with a sealing strip 42, and the magnetic reaction force displacer 35 is arranged in the groove and is located on the inner side of the sealing strip 42.

[0043] In this way, the connection between the upper maintenance structure and the lower maintenance structure is sealed by the sealing strip 42, and the sealing performance after the displacement between the upper maintenance structure and the lower maintenance structure can be guaranteed; in this embodiment, the reliability of the displacement change of the above-mentioned metal displacement block 353 when the repulsive force changes can also be enhanced. The sealing strip 42 in the supporting wall sealing system 4 effectively avoids water seepage during the structural maintenance process, and also ensures that the magnetic reaction force displacer 35 can work normally.

[0044] As attached Figure 3 and attached Figure 4As shown, in another embodiment, a freeze-thaw system 2 is provided in the upper curing structure, the freeze-thaw system 2 includes a heating wire 21 and a dividing block, a cavity is opened in the side wall of the upper curing structure, a plurality of dividing blocks are installed at intervals on the outer side of the cavity, and a plurality of groups of heating wires 21 are installed at intervals on the inner side of the cavity, each group of heating wires 21 is located between two dividing blocks, and the cavity is formed by the heating wires 21 and the dividing blocks to form a circulating liquid path 22 with a serpentine side cross-section, and a circulation port 24 connected to the circulating liquid path 22 is provided at the top of the upper curing structure, and the circulation port 24 can be used for liquid circulation of external equipment. In this embodiment, the circulating liquid path 22 is essentially a spatial passage formed by the inner and outer structures, which provides space for the continuous flow of low-temperature coolant inside it. From the cross-sectional structure, the overall arrangement of the circulating liquid path 22 is an S-shaped arrangement, and the monomer arrangement is a T-shaped arrangement, which avoids the occurrence of convection blockage and improves the circulation efficiency of the circulating cold liquid. The heating wires 21 and the circulating liquid path 22 are alternately distributed at intervals to ensure the orderly progress of the freeze-thaw cycle process, avoid the occurrence of coolant counter-blocking, and improve the overall operation efficiency and heat transfer level of the structure; wherein, the heating wire 21 has a strip-shaped structure. From the cross-sectional view, it is composed of countless groups of heating wires assembled together. From the plane view, it is composed of multiple heating wires 21 spliced ​​and arranged in an S shape.

[0045] In this way, when in use, the sample soil 1 in the upper curing structure can be heated through the heating wire 21, and the sample soil 1 in the upper curing structure can be heat transferred to the sample soil 1 in the lower curing structure through the sample soil 1 in the upper curing structure, so as to truly simulate the transfer situation of the sample soil 1; and the sample soil 1 in the upper curing structure can be cooled through the circulating liquid circuit 22, and similarly, heat transfer can be achieved to the sample soil 1 in the lower curing structure, so as to conveniently carry out freeze-thaw tests.

[0046] Among them, a thermal insulation layer 23 is provided between the heating wire 21 and the circulating liquid circuit 22, and the thermal insulation layer 23 is wrapped on the outside of the heating wire 21, thereby increasing the protection measures for the heating wire 21, avoiding the influence of long-term low temperature on the heating wire 21, and reducing the probability of variable cross-section damage caused by frequent temperature changes. In this embodiment, the outer side of the upper maintenance structure can also be wrapped with a thermal insulation layer 23 as needed. In this way, the heating or cooling effect of the device can be increased. In addition, the thermal insulation layer 23 is arranged on the outside of the circulating liquid circuit, which further avoids the occurrence of metal fatigue caused by frequent temperature changes and extends the service life of the structure. In this embodiment, the thermal insulation layer can be made of a flexible foam material.

[0047] As attached Fig. 9As shown, in another embodiment, a dry-wet system 5 is further included, and the dry-wet system 5 includes an upper permeable electroosmotic plate 55, a lower permeable electroosmotic plate 51, a water storage tank 53 and a water supply layer 54. The side wall of the lower maintenance structure is a lower supporting wall 43, and a water storage tank 53 is opened in the bottom of the lower supporting wall 43. The bottom end of the second test chamber is set as a water supply layer 54 connected to the water storage tank 53. The upper end of the water supply layer 54 is installed with a lower permeable electroosmotic plate 51, and the lower permeable electroosmotic plate 51 covers the bottom of the second test chamber. The upper permeable electroosmotic plate 55 is installed and covers the top of the first test chamber. In this embodiment, the lower supporting wall 43 is provided with a water injection port for injecting water into the water storage tank 53.

[0048] In this embodiment, the interior of the upper permeable electroosmotic plate 55 and the lower permeable electroosmotic plate 51 is a complex grid mesh structure, which has considerable support capacity and strength. At the same time, its internal structure is similar to that of permeable stone, which meets the requirements of water migration and can achieve water penetration. According to the principle of electroosmosis, the porous support absorbs positive and negative ions in the water in the energized state, so that the water is relatively charged and moves to the negative electrode under the action of the electric field. By changing the electrodes of the upper permeable electroosmotic plate 55 and the lower permeable electroosmotic plate 51, the spatial control of water displacement is achieved, thereby achieving the control of the water content in the sample soil 1. In this embodiment, the water storage tank 53 is the lowest structure of the dry-wet system 5, forming an effective storage space for water. The water supply layer 54 is connected to the water storage tank 53. Through its own capillary action and strong water absorption, it ensures the long-term contact between the lower permeable electroosmotic plate 51 and the water body, thereby achieving the water supply of the sample soil 1 during the circulation process.

[0049] The upper permeable electroosmotic plate 55 and the lower permeable electroosmotic plate 51 are densely woven skeleton structures, which ensure that the water can move freely while also ensuring that it has a certain support capacity, and can form an effective vertical constraint on the sample soil 1, effectively realizing the effective movement of water during the dry-wet cycle, avoiding the migration of soil particles and causing water retention in the soil, and ensuring the accuracy and reliability of the dry-wet cycle process. Through the electrode changes of the upper permeable electroosmotic plate 55 and the lower permeable electroosmotic plate 51 and the constant water volume control of the water storage tank 53, the positive and negative ions in the pore water in the sample soil 1 are adsorbed through electroosmosis, realizing the quantitative and directional movement of the pore water, and then realizing the dry-wet cycle process of the sample soil 1. At the same time, the moisture content of the sample during the dry-wet cycle is controlled, which improves the overall reliability and accuracy of the test.

[0050] The lower support wall 43 is provided with a through hole for connecting the water storage bin 53 with the water supply layer 54. In this embodiment, the upper and lower support walls can be made of stainless steel. The height of the water storage bin 53 is consistent with the height from the upper edge of the lower water-permeable electroosmotic plate 51 to the bottom of the water storage bin 53; the water supply layer can be made of a strong water-absorbing material with capillary action, and the upper part is connected to the lower water-permeable electroosmotic plate 51, and its height is the difference between the height of the water storage bin 53 and the height of the lower water-permeable electroosmotic plate 51.

[0051] Among them, a number of limiting feet 52 for supporting the lower water-permeable electroosmotic plate 51 are installed on the inner side wall of the lower supporting wall 43 located at the lower end of the lower water-permeable electroosmotic plate 51, and the limiting feet 52 limit the displacement of the lower water-permeable electroosmotic plate 51 through the extended part; at the same time, the limiting feet 52 can be a metal structure, connected to the inner wall corresponding to the water storage tank 53, and can avoid the risk of the sample soil 1 being immersed in the water in the water storage tank 53 for a long time. In this embodiment, a placement groove for inserting and placing the lower water-permeable electroosmotic plate 51 can also be opened on the inner side wall of the lower supporting wall 43, so as to further facilitate the installation and fixation of the lower water-permeable electroosmotic plate 51. The limiting feet 52 effectively constrain the displacement of the lower water-permeable electroosmotic plate 51 during the dry-wet cycle through the triangular structure, avoid the occurrence of uneven water distribution in the soil sample 1, and effectively improve the scientific nature of the experiment and the accuracy of the obtained data.

[0052] As attached Figure 7 As shown, in another embodiment, a geobag constraint frame 31 and a geotextile 32 are also included. A vertical geobag constraint groove 33 is opened in the middle of the lower edge of the upper maintenance structure connected to the lower maintenance structure. The geotextile 32 can be laid between the first test cavity and the second test cavity. The geobag constraint frame 31 is used to surround and clamp the edge of the geotextile 32, and the geobag constraint frame 31 is provided with an end that can be vertically inserted into the geobag constraint groove 33; the lower end edge of the upper maintenance structure is located on the outside of the geobag constraint groove 33 as an upper support wall 41, and the upper support wall 41 is used to abut against the upper end surface of the magnetic reaction force displacer 35. In the present embodiment, the lower edge of the upper curing structure is located at the lower end of the inner wall of the geobag constraint groove 33, and a space is reserved for the geobag constraint frame 31 to extend out, and the inner wall can open a cavity as needed, and a heating wire 21, a dividing block and a thermal insulation layer 23 are set; in the present embodiment, the lower edge of the upper curing structure is located at the lower end of the inner wall of the geobag constraint groove 33, and a magnetic reaction force displacer 35 can be set as needed.

[0053] In this embodiment, the upper part of the geobag constraint frame 31 is a double-layer filamentary metal structure, the cross-section is an inverted bullet-shaped, the surrounding side is a metal strip structure, and the contact surface with the geotextile 32 is a plane. The geotextile 32 is constrained by the rigidity of the double-layer filamentary metal structure. The height and width of the metal strip structure on the surrounding side are consistent with the height and width of the geobag constraint groove 33. When in use, the geobag constraint frame 31 is clamped and inserted into the geobag constraint groove 33. The part of the geobag constraint groove 33 that contacts the upper and lower structures is an inverted bullet-shaped groove, and the length, width, shape and size of the groove are consistent with the double-layer filamentary metal structure in the geobag constraint frame 31. The part of the geobag constraint groove 33 that is embedded in the upper structure is a vertical groove, and the length, width, structure, shape and size of the vertical groove are consistent with the peripheral metal-like strip structure in the geobag constraint frame 31. The geobag constraint groove 33 and the geobag constraint frame 31 can fit together after being spliced, and the inner wall surface of the geobag constraint groove 33 is a frosted surface. In this embodiment, the geotextile 32 can be a single-layer geotextile woven in warp and weft. After unfolding, the geotextile 32 has a cross-shaped structure, and the length of the peripheral geotextile 32 is slightly less than the height of the peripheral metal-like strip in the geobag constraint frame 31. The surfaces of the geobag constraint frame 31 and the geobag constraint groove 33 are both frosted surfaces, which improves the friction resistance of the contact interface between the geobag constraint frame 31 and the geobag constraint groove 33 and ensures the reliability and stability of the connection between the two structures.

[0054] The double-layer filamentary metal structure on the upper part of the geobag constraint frame 31 and the metal strip structure on the surrounding side avoid the influence of the protrusions on the contact surface and reduce the test error in the shearing process while ensuring that the geobag can be effectively constrained. The inverted bullet-shaped section can perfectly fit with the geobag constraint groove 33, reducing the risk of the interface contact structure falling off and avoiding the error influence of this factor on the test.

[0055] After the sample soil 1 inside the maintenance structure is filled, the geobag constraint frame 31 is inserted into the geobag constraint groove 33 reserved in the upper structure, and the geotextile 32 fits tightly with the upper and lower sample soils 1; the disassembly and installation of the geotextile 32 are realized through the settings of the geobag constraint frame 31 and the geotextile 32, so as to facilitate the simulation of the geobag on demand, so as to distinguish the heat transfer changes and dryness and humidity changes between the sample soil 1 in the geobag and the sample soil 1 outside the geobag, thereby increasing the test applicability and functionality of the device; at the same time, the misalignment and sliding phenomenon caused by the loose fit of the bag-soil interface is effectively avoided, and the test errors caused thereby are effectively avoided.

[0056] The steps of using the utility model are as follows:

[0057] S1: Separate the upper curing structure and the lower curing structure, add a predetermined amount of distilled water from the upper part of the water supply layer 54, and then add the pre-calculated variable water content into the lower curing structure;

[0058] S2: After the filling is completed, vaseline is applied to the inner walls of the upper curing structure and the lower curing structure, and the sample soil 1 is placed in the first test cavity and the second test cavity, and the interface contact system 3 is cleared;

[0059] S3: After cutting the geotextile 32 to a specified size, clamp it in the geobag constraint frame 31. After installation, insert the combination of the geobag constraint frame 31 and the geotextile 32 into the geobag constraint groove 33 using the end of the geobag constraint frame 31. After insertion, ensure that the geobag constraint groove 33 is in the same height as the surrounding structure.

[0060] S4: After the assembly is inserted, the upper curing structure and the lower curing structure are connected and closed to form an integrated structure, and then left to stand naturally for 24 hours;

[0061] S5: After the static state is completed, different control steps are performed according to the actual test environment;

[0062] S6: Wet-dry cycle process:

[0063] S6-1: an external electrode converter is connected and powered on. During the humidification process, the upper water-permeable electroosmotic plate 55 of the upper curing structure is the negative electrode, and the lower water-permeable electroosmotic plate 51 of the lower curing structure is the positive electrode. During the dehumidification process, the opposite is true.

[0064] S6-2: According to the electroosmosis speed, the dry-wet cycle process is controlled by controlling the electroosmosis process time to ensure that the state of the sample soil 1 is consistent after each cycle;

[0065] S6-3: When the dry-wet cycle ends, disconnect the power supply of the electrode converter, and then disconnect the connection between the maintenance structure and the external electrode converter to complete the dry-wet cycle process.

[0066] S7: Freeze-thaw cycle process:

[0067] S7-1: Connect an external cooling circulation pump and a heating power supply. During the cooling phase, turn on the cooling circulation pump to cool down the internal sample soil 1. After reaching the preset temperature, maintain the temperature for 6 hours. During the heating phase, turn on the heating power supply to heat the internal sample soil 1. After reaching the preset temperature, maintain the temperature for 6 hours.

[0068] S7-2: When the freeze-thaw cycle ends, the heating power supply is disconnected, the coolant in the circulating liquid circuit is emptied, and then the cooling circulation pump is disconnected to complete the freeze-thaw cycle process;

[0069] S8: According to the parameters of the sample soil 1, a metal displacement block 353 of corresponding mass is selected. During the dry-wet cycle and freeze-thaw cycle, the sample soil 1 deforms and exerts force on the pressure plate 34, and the resistance value of the internal resistance changes, the current in the circuit changes, and the magnetic reaction force displacement device 35 produces an equal amount of deformation of the sample soil 1;

[0070] S9: End the cycle, separate the upper curing structure and the lower curing structure, and take out the sample soil 1.

[0071] The technical principle of the utility model is: after the external structure of the device and the internal sample soil 1 are assembled according to the installation plan, the force sense is reset to zero. In the freeze-thaw cycle test, the temperature of the sample soil 1 inside the structure is controlled by the heating wire 21 and the circulating liquid circuit 22 of the freeze-thaw system 2; when the temperature drops, the liquid water in the soil pores condenses and turns into solid water, and the soil volume expands. At this time, the pressure plate 34 in the interface contact system 3 senses the change in soil pressure, and the current changes, prompting the magnetic reaction force displacement device 35 to produce a coordinated deformation amount consistent with the soil expansion amount. When the temperature rises, the solid water in the soil pores turns into liquid water, the soil pressure on the pressure plate 34 decreases, and the magnetic reaction force displacement device 35 coordinates to restore to the original state under the action of the structure's own weight. In the dry-wet cycle test, the controllable change of the moisture content of the sample inside the structure is achieved by the electrode transformation of the upper permeable electroosmotic plate 55 and the lower permeable electroosmotic plate 51. When the sample soil inside the structure is a special soil such as expansive soil, the soil expands when it meets water. At this time, the pressure plate 34 in the interface contact system 3 senses the change in soil pressure, and the current changes, prompting the magnetic reaction force displacer 35 to produce a coordinated deformation consistent with the soil expansion. When the soil loses water and shrinks, as the pressure exerted by the soil on the pressure plate 34 in the interface contact system 3 dissipates, the magnetic reaction force displacer 35 coordinates to restore to its original state under the action of the structure's own weight.

[0072] In the freeze-thaw cycle test, the temperature of the sample inside the structure is controllably changed through the heating wire 21 and the circulating liquid circuit 22 of the freeze-thaw system. When the temperature drops, the liquid water in the pores turns into solid water, the soil volume expands, and pressure is exerted on the side wall. The pressure plate in the interface contact system senses the change in soil pressure, the internal resistance of the pressure plate 34 decreases, and the current decreases. According to Maxwell's electromagnetic force formula: Among them, F is the electromagnetic attraction, B is the magnetic induction intensity, S is the magnetic pole area, μ0 is the vacuum magnetic permeability (constant constant), and according to the magnetic induction intensity formula Among them, N is the number of coil turns, I is the current intensity, and δ is the air gap length (approximately a constant). As the current increases, the magnetic induction intensity B increases accordingly, and then the electromagnetic force increases accordingly, causing the displacement of the magnetic reaction force displacer 35 to increase, which is consistent with the soil expansion, achieving synchronous and coordinated deformation.

[0073] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. used in the utility model are only for the convenience of description and are not used to limit the scope of implementation of the utility model. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the utility model without substantially changing the technical content.

[0074] The above are only preferred implementations of the utility model. The protection scope of the utility model is not limited to the above embodiments. All technical solutions under the idea of ​​the utility model belong to the protection scope of the utility model. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the utility model should be regarded as the protection scope of the utility model.

Claims

1. A composite curing device for soil-structure contact surface testing, characterized in that: The invention comprises an upper maintenance structure, a lower maintenance structure and an interface contact system (3), wherein a first test cavity is provided at the lower end of the upper maintenance structure, and a second test cavity is provided at the upper end of the lower maintenance structure, and the upper maintenance structure can cover the upper end of the lower maintenance structure, and the first test cavity is connected to the second test cavity; the interface contact system (3) comprises a pressure plate (34), a magnetic reaction force displacer (35) and a power source (37), wherein a pressure plate (34) is provided on the inner side of the second test cavity, and a magnetic reaction force displacer (35) is provided at the upper end of the edge of the lower maintenance structure, and the upper end of the magnetic reaction force displacer (35) is used to abut against the edge of the lower end of the upper maintenance structure, and the magnetic reaction force displacer (35), the pressure plate (34) and the power source (37) are electrically connected to each other.

2. A composite curing device for soil-structure contact surface testing according to claim 1, characterized in that: The magnetic reaction force displacer (35) comprises an electromagnetic coil (351), an iron core (352) and a metal displacement block (353); a plurality of iron cores (352) are vertically mounted on the upper end of the edge of the lower maintenance structure; electromagnetic coils (351) are respectively wound around the outer sides of the iron cores (352); a metal displacement block (353) is disposed at the upper end of the iron core (352); the upper end of the metal displacement block (353) is used to abut against the lower end surface of the upper maintenance structure; the electromagnetic coil (351) is connected in series with the pressure plate (34); and the electromagnetic coil (351) and the pressure plate (34) are connected to a power source (37) via a wire (36).

3. The composite curing device for soil-structure contact surface testing according to claim 1, characterized in that: The pressure plate (34) adopts a resistive pressure sensor.

4. The composite curing device for soil-structure contact surface testing according to claim 1, characterized in that: The upper end of the lower maintenance structure is provided with a circle of outwardly extending flanges, the edge of the lower maintenance structure and the upper end of the flange are jointly provided with a groove into which the lower end of the upper maintenance structure can be inserted, the inner side wall of the groove is provided with a sealing strip (42), and the magnetic reaction force displacer (35) is arranged in the groove and is located on the inner side of the sealing strip (42).

5. The composite curing device for soil-structure contact surface testing according to claim 1, characterized in that: The upper curing structure is provided with a freeze-thaw system (2), the freeze-thaw system (2) comprising a heating wire (21) and a partition block, a cavity is provided in the side wall of the upper curing structure, a plurality of partition blocks are installed at intervals on the outer side of the cavity, and a plurality of groups of heating wires (21) are installed at intervals on the inner side of the cavity, each group of the heating wires (21) is located between two partition blocks, the cavity is formed by the heating wires (21) and the partition blocks to form a circulating liquid path (22) with a serpentine side cross-section, and a circulation port (24) connected to the circulating liquid path (22) is provided at the top of the upper curing structure, and the circulation port (24) can be used for external equipment to circulate the liquid path.

6. A composite curing device for soil-structure contact surface testing according to claim 5, characterized in that: A temperature insulation layer (23) is provided between the heating wire (21) and the circulating liquid path (22), and the temperature insulation layer (23) is wrapped around the outside of the heating wire (21).

7. The composite curing device for soil-structure contact surface testing according to claim 1, characterized in that: The invention also comprises a dry-wet system (5), wherein the dry-wet system (5) comprises an upper water-permeable electroosmotic plate (55), a lower water-permeable electroosmotic plate (51), a water storage bin (53) and a water supply layer (54); the side wall of the lower maintenance structure is a lower supporting wall (43); a water storage bin (53) is provided in the bottom of the lower supporting wall (43); the bottom end of the second test chamber is provided with a water supply layer (54) connected to the water storage bin (53); the upper end of the water supply layer (54) is provided with a lower water-permeable electroosmotic plate (51); the lower water-permeable electroosmotic plate (51) covers the bottom of the second test chamber; and the upper water-permeable electroosmotic plate (55) is provided to cover the top of the first test chamber.

8. A composite curing device for soil-structure contact surface testing according to claim 7, characterized in that: The lower supporting wall (43) is provided with a through hole for connecting the water storage tank (53) with the water supply layer (54).

9. The composite curing device for soil-structure contact surface testing according to claim 7, characterized in that: A plurality of limiting feet (52) for supporting the lower water-permeable electro-osmotic plate (51) are installed on the inner side wall of the lower supporting wall (43) located at the lower end of the lower water-permeable electro-osmotic plate (51).

10. The composite curing device for soil-structure contact surface testing according to claim 1, characterized in that: It also includes a geobag constraint frame (31) and a geotextile (32); a vertical geobag constraint groove (33) is provided in the middle of the lower edge of the upper maintenance structure; the geotextile (32) can be laid between the first test cavity and the second test cavity; the geobag constraint frame (31) is used to clamp the edge of the geotextile (32); and the geobag constraint frame (31) is provided with an end that can be inserted into the geobag constraint groove (33); the lower edge of the upper maintenance structure is located outside the geobag constraint groove (33) and is an upper support wall (41); the upper support wall (41) is used to abut against the upper end surface of the magnetic reaction force displacer (35).

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