A wall-soil contact deformation simulation test device

Abstract

The application discloses a wall-soil contact deformation simulation test device, which comprises an outer box body and an inner box body. A soil body support seat is arranged on the bottom plate of the outer box body. Support arms are arranged between the four side plates of the outer box body and the four side walls of the soil body support seat. The four side plates of the inner box body stand on the support arms. The bottom end sides of the four side plates of the inner box body are sealed by a round rod arranged in a circular groove horizontally. Rollers are arranged on the inner sides of the four side plates of the outer box body. The rollers support the four side plates of the inner box body. A plurality of pressing plates are arranged side by side in the length direction of the inner box body at the top end of the soil body surrounded by the four side plates of the inner box body. A soil body pressing jack is arranged between each pressing plate and the top plate of the outer box body. A spacing space is arranged between the two pressing plates. A seepage-proof wall plate is arranged in the soil body downwards of the spacing space. The device can be assembled and adjusted in size to realize a meter-level scale model box. The dam body is simulated in layered filling and water storage load by the jacks in stages and in regions.

Description

Technical Field

[0001] This invention relates to a test apparatus for simulating wall-soil contact deformation. Background Technology

[0002] Earth-rock dams built on deep overburden layers often employ concrete cutoff walls for seepage prevention. Determining the appropriate stress on the concrete cutoff wall is a key challenge and core issue in its design. On one hand, the cutoff wall is subjected to earth pressure (core dam) or water pressure (face dam) acting vertically on its top, and earth and water pressure acting horizontally on its sides. On the other hand, the concrete cutoff wall and the overburden soil form a system of mutual contact. The constraint of the soil on the cutoff wall and the differential settlement between the cutoff wall and the soil on either side create frictional forces between the soil and the wall's sidewalls. The deformation of the cutoff wall also affects the magnitude of these forces. Currently, there is a lack of unified and in-depth understanding both domestically and internationally regarding the mechanical properties of cutoff walls and the wall-soil interaction in deep overburden layers. Existing simulation technologies mainly employ centrifugal model tests and small-scale model box tests. The problems are that after the cutoff wall is significantly scaled down, similar materials can only be used as substitutes based on similarity relationships. The connection type between cutoff wall sections and the particle size distribution and stratification characteristics of the overburden soil cannot be accurately depicted. It is difficult to simulate the effect of external loads generated after the dam is constructed in layers and impounded on the cutoff wall and overburden. The small model results in small contact deformation and differential settlement values ​​between the wall and soil under external loads, amplifying the impact of experimental and measurement errors on the results. It is impossible to achieve a true depiction of the wall-soil contact interaction and accurate simulation of the stress-deformation law of the cutoff wall.

[0003] Therefore, existing simulation technologies mainly employ centrifugal model tests and small-scale model chamber tests, which have the following drawbacks: (1) After the seepage barrier wall is greatly reduced in size, similar materials can only be used to replace it based on similar relationships. The connection type between the sections of the seepage barrier wall and the particle size distribution and stratification characteristics of the overburden soil cannot be accurately described.

[0004] (2) It is difficult to simulate the effect of the external load generated after the dam body is filled in layers and impounded with water on the anti-seepage wall and the cover layer.

[0005] (3) The small model results in smaller contact deformation and differential settlement between the wall and soil under external load, which amplifies the impact of experimental and measurement errors on the results.

[0006] (4) There are currently no large-scale simulation test devices and technologies. Summary of the Invention

[0007] The purpose of this invention is to provide a wall-soil contact deformation simulation test device to address the above-mentioned problems.

[0008] To achieve the above objectives, the solution of the present invention is as follows: A wall-soil contact deformation simulation test device includes an outer box and an inner box. The inner box is a rectangular box. A soil support seat is set on the bottom plate of the outer box. Support arms are set between the four side plates of the outer box and the four side walls of the soil support seat. The four side plates of the inner box stand on the support arms. The bottom side of the four side plates of the inner box is sealed to the soil support seat by a horizontally arranged round rod with an arc groove. A roller seat is set inside the four side plates of the outer box, and a roller is set in the roller seat. The roller presses against the four side plates of the inner box, forming a lateral sliding support between the inner and outer boxes. Multiple pressure plates are arranged side by side along the length of the inner box at the top of the soil surrounded by the four side plates of the inner box. The width of the pressure plates is the same as the width of the inner box, forming the top cover of the inner box. A soil pressure jack is set between each pressure plate and the top plate of the outer box. A space is provided between two pressure plates in the middle of the top cover. A seepage-proof wall panel is installed in the soil. The top of the seepage-proof wall panel protrudes from the soil through the space. The top of the seepage-proof wall panel is a straight plate. The lower ends of the straight plate are supported horizontally on the pressure plates on both sides by rollers. A seepage-proof wall panel pressure jack is installed between the straight plate and the top plate of the outer box. A ball bearing row is installed between the seepage-proof wall panel pressure jack and the top plate of the outer box, which allows the seepage-proof wall panel pressure jack to be in a horizontally movable state. Pressure sensors are installed on both sides of the seepage-proof wall panel and in the soil. A stress fiber optic sensor is installed in the seepage-proof wall panel to monitor the stress of the seepage-proof wall. Displacement sensors are distributed in the soil. A monitoring and control server is connected to the soil pressure jack, the seepage-proof wall panel pressure jack, the pressure sensors, the stress fiber optic sensor, and the displacement sensor.

[0009] A further aspect of the solution is that the four sides of the outer casing are assembled in segments from bottom to top.

[0010] The solution is further as follows: the four side panels of the inner box are composed of multiple upright panels spliced ​​together, and grooves are respectively provided on the end face between two upright panels. A rubber rod is placed in the groove between two upright panels, and the rubber rod forms a flexible connection between the upper and lower upright panels. Arc-shaped protective plates are respectively provided on the inner and outer sides of the splice seam between the upper and lower upright panels.

[0011] A further aspect of the solution is that each upright plate is held in place by at least two rollers, one vertically and one vertically, with respect to the side plate of the outer casing.

[0012] A further aspect of the solution is that two circular rods are provided at intervals between the bottom ends of the four side panels of the inner box and the soil support base.

[0013] A further aspect of the solution is that the top of the impermeable wall panel is always under pressure.

[0014] A further aspect of the solution is that the inner enclosure has a tempered glass observation window on its side panel, and the monitoring and control server is connected to a high-speed camera. The high-speed camera is positioned facing the glass observation window to collect dynamic images of the soil after it has been compressed.

[0015] A further aspect of the scheme is that the pressure sensors in the soil are arranged in layers, and the displacement sensors are fiber optic displacement sensors, which are arranged in a Z-shape from top to bottom in the soil.

[0016] A further step in the solution is that the impermeable wall panel is placed and positioned in the soil during the process of assembling the outer box in sections from bottom to top on all four sides, while filling the inner box with soil.

[0017] The beneficial effects of this invention are: (1) It can be spliced ​​and assembled, and the model size can be adjusted to realize meter-scale model boxes. The concrete anti-seepage wall can be made of actual materials, and the cover layer can be made of original soil. The layered depiction is more refined, especially when there is a thin interlayer.

[0018] (2) By using jacks to load in stages and areas, the simulation of the dam body layer filling and water storage load is realized.

[0019] (3) The contact deformation and differential settlement between the wall and the soil are greater, which reduces the impact of test and measurement errors.

[0020] (4) The inner and outer double-layer box structure is adopted. The outer box is a load-bearing structure, and the inner box adopts a floating ring structure with reserved space at the bottom. The box is spliced ​​in layers and equipped with expansion joints, which can deform together with the soil in sections, thus solving the problem of loss in the process of vertical external load being transmitted downward due to friction between the soil and the box.

[0021] (5) The inner and outer boxes are supported by rollers to reduce the frictional resistance between the inner and outer boxes when the inner box moves downward under vertical load, thereby reducing vertical load loss.

[0022] (6) The upper part of the anti-seepage wall is loaded with a movable jack to ensure the vertical load on the wall and prevent eccentric pressure.

[0023] The invention will be further explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the front cross-section of the structure of the present invention; Figure 2 This is a schematic cross-sectional view of the structure of the present invention. Figure 3 This is a schematic diagram showing the contact between the straight panel and the pressure plates on both sides of the waterproof wall panel. Figure 1 Enlarged view of part A; Figure 4 A schematic diagram showing the contact between the pressure jack applied to the seepage-proof wall panel and the top plate of the outer casing. Figure 1 Enlarged view of part B; Figure 5 This is a schematic diagram of the sensor arrangement of the present invention. Detailed Implementation

[0025] A wall-soil contact deformation simulation test device, such as Figures 1 to 5 As shown, the test apparatus includes an outer casing 1 and an inner casing 2. The inner casing 2 is a rectangular box, and the outer casing 1 encloses the inner casing 2, wherein: as... Figure 1 , 2 As shown in Figure 5, the outer casing 1 adopts a segmented assembly structure from bottom to top, with the upper and lower sections connected by flanges. A rigid support plate and soil support seat 3 are provided on the bottom plate of the outer casing. Support arms 4 are provided between the four side plates of the outer casing and the four side walls of the soil support seat. The bottom ends of the support arms 4 extend out of the four side plates of the outer casing and are fixed. Support columns 5 are provided between the extended support arms 4 and the bottom plate of the outer casing. The four side plates 201 of the inner casing stand on the support arms 4. The bottom ends of the four side plates 201 of the inner casing are connected to the soil support seat 3 by arc-shaped grooves. A flat, round rod 6 is used for sealing, with two rods 6 spaced vertically at intervals. Roller seats 7 are provided on the inner sides of the four side panels of the outer casing, and rollers 8 are installed within the roller seats 7. The rollers 8 press against the four side panels 201 of the inner casing, creating lateral sliding support between the inner casing 2 and the outer casing 1. This effectively solves the problem of the inner casing 2 being able to slide freely after being subjected to downward frictional force by the soil within it. Multiple pressure plates 10 are arranged side-by-side along the length of the inner casing at the top of the soil 9 enclosed by the four side panels. The width of the pressure plates 10 is equal to the width of the inner casing 2. Figure 1The thickness of the inner box 2 is consistent between the front and rear sections to form the inner box top cover. A soil pressure jack 11 (pneumatic or hydraulic) is installed between each of the pressure plates 10 and the outer box top plate 101. A space is provided between two pressure plates in the middle of the top cover. A seepage-proof wall panel 12 (concrete-cast seepage-proof wall panel) is installed in the soil 9. The top of the seepage-proof wall panel 12 protrudes from the soil 9 through the space. The width of the seepage-proof wall panel 12 is the same as or half the width of the inner box 2. The depth of the seepage-proof wall panel 12 in the soil 9 is half the thickness of the soil 9 or deeper, depending on the purpose of the experiment. To ensure that the seepage-proof wall panel 12 remains in a natural state after being compressed, a straight plate 901 is installed at the top of the seepage-proof wall panel 12. The lower ends of the straight plate 901 are horizontally supported on the pressure plates by rollers 902. A seepage-proof wall panel pressure jack 13 is installed between the plate 901 and the top plate 101 of the outer casing. A ball bearing assembly 14 is installed between the seepage-proof wall panel pressure jack 13 and the top plate 101 of the outer casing, allowing the seepage-proof wall panel pressure jack 13 to be horizontally movable. The lower ends of both sides of the plate 901 are horizontally supported on the side pressure plates by rollers 902, and the seepage-proof wall panel pressure jack 13 and the top plate 101 of the outer casing are also connected. The structure with ball bearings 14 allows the soil to deform together with the anti-seepage wall panel 13 after being subjected to vertical loads applied by the jacks 11 and lateral earth pressures. This ensures that the vertical loads applied by the anti-seepage wall panel jacks 13 to the anti-seepage wall panel 12 are not eccentric. Furthermore, the top of the anti-seepage wall panel 12 is always under pressure, meaning that the anti-seepage wall panel jacks 13 always apply pressure to the anti-seepage wall panel 12.

[0026] In this embodiment: the seepage-proof wall panel 12 is placed and positioned in the soil 9 during the process of assembling the four sides of the outer box 1 in sections from bottom to top, while filling the inner box 2 with soil.

[0027] Furthermore, a through hole is provided on the lower side of the outer box, and the support arm passes through the through hole and rests on the side wall of the soil support seat to form a removable support arm for the four side plates of the inner box; after the support arm is removed, the soil inside the inner box 2 is subjected to the downward frictional force of the soil, and the inner box 2 can slide freely.

[0028] like Figure 2As shown, pressure sensors 15 are respectively installed on both sides of the seepage-proof wall panel 12 and in the soil 9. A stress fiber optic sensor 1201 is installed inside the seepage-proof wall panel 12. The stress fiber optic sensor 1201 is installed inside the seepage-proof wall panel 12 and integrated with it during the manufacturing process. It is used to monitor the stress of the seepage-proof wall. Displacement sensors 16 are distributed in the soil 9. The pressure sensors 15 in the soil are arranged in layers. The displacement sensors 16 are displacement fiber optic sensors, which are arranged in a Z-shape from top to bottom in the soil. A monitoring and control server 17 is connected to the soil pressure jack 11, the seepage-proof wall panel pressure jack 13, the pressure sensors 15, the stress fiber optic sensor 1201, and the displacement sensors 16. The signals are led out from the interface 10-1 set on the pressure plate 10 and connected to the monitoring and control server 17.

[0029] In order to flexibly control the height of the box according to the experimental purpose: the four side panels 201 of the inner box are composed of multiple vertical panels 201-1 spliced ​​together. The end face between two vertical panels is provided with grooves 201-1-1 respectively. A rubber rod 201-2 is placed in the groove between two vertical panels. The rubber rod 201-2 forms a flexible connection between the upper and lower vertical panels 201-1. Arc-shaped protective plates 18 are provided on the inner and outer sides of the splice joint of the upper and lower vertical panels 201-1 to prevent soil from entering the splice joint.

[0030] Wherein: each of the upright plates is supported by at least two rollers 8 at the top and bottom of the outer box side plate.

[0031] To more intuitively observe the changes in the soil after compression, the inner box is equipped with a tempered glass observation window 202 on the side plate. The monitoring and control server 17 is connected to a high-speed camera 19, which is set to face the glass observation window 202 to collect dynamic images of the soil after compression.

[0032] The above embodiments can be spliced ​​and assembled, and the model size can be adjusted to realize meter-scale model boxes. The concrete anti-seepage wall can be made of actual materials, and the cover layer can be made of undisturbed soil. The layered depiction is more detailed, especially when there are thin interlayers.

[0033] This embodiment simulates the layered filling and water storage load of the dam body by using jacks for graded and regional loading. The contact deformation and differential settlement between the wall and soil are greater, reducing the impact of experimental and measurement errors.

[0034] This embodiment employs a double-layered box structure. The outer box serves as the load-bearing structure, while the inner box utilizes a floating ring structure with reserved space at the bottom. The boxes are assembled in layers and equipped with expansion joints, allowing them to deform in sections with the soil. This solves the problem of vertical load loss caused by friction between the soil and the box during downward transmission. Roller supports are used between the inner and outer boxes to reduce frictional resistance between the inner and outer boxes when the inner box moves downward under vertical loads, thus minimizing vertical load loss. Movable jacks are used for loading the upper part of the seepage-proof wall to ensure the vertical load on the wall and prevent eccentric compression.

Claims

1. A wall-soil contact deformation simulation test device, characterized in that, The experimental apparatus includes an outer box and an inner box. The inner box is a rectangular box. A soil support seat is provided on the bottom plate of the outer box. Support arms are provided between the four side plates of the outer box and the four side walls of the soil support seat. The four side plates of the inner box stand on the support arms. The bottom of the four side plates of the inner box and the soil support seat are sealed by a horizontally arranged round rod with an arc groove. A roller seat is provided inside the four side plates of the outer box, and a roller is provided in the roller seat. The roller presses against the four side plates of the inner box, forming a lateral sliding support between the inner and outer boxes. Multiple pressure plates are arranged side by side along the length of the inner box at the top of the soil surrounded by the four side plates of the inner box. The width of the pressure plates is the same as the width of the inner box, forming the top cover of the inner box. A soil pressure jack is provided between each pressure plate and the top plate of the outer box. A space is provided between the two pressure plates in the structure. A seepage-proof wall panel is installed in the soil, with its top protruding from the space. The top of the seepage-proof wall panel is a straight plate, and the lower ends of both sides of the straight plate are supported horizontally on the pressure plates via rollers. A seepage-proof wall panel pressure jack is installed between the straight plate and the top plate of the outer casing. A ball bearing system is installed between the seepage-proof wall panel pressure jack and the top plate of the outer casing, allowing the seepage-proof wall panel pressure jack to be horizontally movable. Pressure sensors are installed on both sides of the seepage-proof wall panel and in the soil. A stress fiber optic sensor is installed inside the seepage-proof wall panel to monitor the stress of the seepage-proof wall. Displacement sensors are distributed in the soil. A monitoring and control server is connected to the soil pressure jack, the seepage-proof wall panel pressure jack, the pressure sensors, the stress fiber optic sensor, and the displacement sensor.

2. The experimental apparatus according to claim 1, characterized in that, The outer casing has a segmented assembly structure on all four sides from bottom to top.

3. The test apparatus according to claim 1 or 2, characterized in that, The four side panels of the inner box are composed of multiple upright panels spliced ​​together. Grooves are provided on the end faces between two upright panels. Rubber rods are placed in the grooves between two upright panels, and the rubber rods form a flexible connection between the upper and lower upright panels. Arc-shaped protective plates are provided on the inner and outer sides of the splice seam between the upper and lower upright panels.

4. The experimental apparatus according to claim 3, characterized in that, Each of the upright panels is held in place by at least two rollers, one vertically and one vertically, between itself and the side panel of the outer casing.

5. The experimental apparatus according to claim 1, characterized in that, Two round rods are provided at intervals between the bottom of the four side plates of the inner box and the soil support seat.

6. The experimental apparatus according to claim 1, characterized in that, The top of the waterproof wall panel is always under pressure.

7. The experimental apparatus according to claim 1, characterized in that, The inner enclosure has a tempered glass observation window on the side panel, and the monitoring and control server is connected to a high-speed camera. The high-speed camera is positioned facing the glass observation window to collect dynamic images of the soil after it is compressed.

8. The test apparatus according to claim 1, characterized in that, The pressure sensors in the soil are arranged in layers, and the displacement sensors are fiber optic displacement sensors, which are arranged in a Z-shape from top to bottom in the soil.

9. The experimental apparatus according to claim 2, characterized in that, The impermeable wall panel is placed and positioned in the soil during the process of assembling the outer box into sections from bottom to top on the four sides, and when filling the inner box with soil.

Images