Movable door device and test method for measuring soil arching effect in overlapping tunnels

Abstract

The present invention provides a movable door device and a test method for measuring soil arch effect of overlapping tunnels. The movable door device includes a box, a movable door, a tunnel model and a three-dimensional scanner, wherein the movable door is horizontally arranged in the box, a plurality of soil pressure boxes are arranged on the movable door, the space surrounded by the upper surface of the movable door and the box is used to accommodate soil, and the tunnel model is arranged in the soil; the movable door can move; the movement of the movable door can cause the soil to collapse, and the soil pressure box can measure the vertical soil pressure of the soil; the three-dimensional scanner is arranged in the box and below the movable door, and the three-dimensional scanner can measure the arch axis of the soil forming the soil arch effect. The movable door device and the test method can be used to test the soil arch effect generated by spaces of different widths in overlapping tunnels.

Description

Technical Field

[0001] The invention relates to the field of civil engineering and geotechnical engineering test devices, and in particular to a movable door device and a test method for measuring soil arch effect of overlapping tunnels. Background Art

[0002] The "soil arch effect" caused by the support structure is the most critical problem in underground engineering. It is widely present in underground engineering, such as tunnel excavation, foundation pit support and other projects. Its essence is a phenomenon of stress transfer. This stress transfer is achieved due to the uneven deformation of the soil under external force.

[0003] In tunnel engineering, tunnel load mainly comes from the surrounding rock. Under the action of load or self-weight, the soil is compressed and deformed, resulting in uneven settlement, which causes the soil particles to "wedge" each other, thus producing a "soil arch effect" in a certain range of soil layers. Due to the existence of the soil arch effect, the active earth pressure behind the retaining structure is redistributed. Fully studying the mechanism of the "soil arch effect" and making full use of its stress redistribution characteristics have become the main research directions.

[0004] As early as 1884, British scientist Roberts first discovered the "granary effect": the force on the bottom of the granary reaches a maximum value and remains unchanged after the grain is piled up to a certain extent. This is commonly known as the soil arch effect. In 1895, German engineer Janssen used a continuous medium model to quantitatively explain it. In 1943, Terzaghi confirmed the existence of the soil arch effect in the field of soil mechanics through the famous "moving door" experiment, and based on the description of the stress distribution of the soil arch, he derived the conditions for the existence of the soil arch effect. However, Terzaghi's "moving door" experiment can only study the "soil arch effect" of a fixed width, and cannot study the "soil arch effect" of multiple widths on one device.

[0005] In the experimental research on the "soil arch effect", the invention patent with patent number CN 102680390 A discloses a test device for simulating the soil arch effect caused by tunnel excavation. Based on the original Terzaghi test, the device adds a removable plate design, so that the width can be changed to a certain extent for testing. However, this width change is fixed and can only be an integer multiple of the width of the removed plate, and the width cannot be adjusted steplessly.

[0006] In the existing movable door test device, the "soil arch effect" in the plane state is observed, and the plane strain problem is studied. However, the "soil arch effect" exists in the entire soil body and is a spatial effect. It is not comprehensive to consider it only as a plane strain problem. In addition, as the number of overlapping tunnels is gradually increasing, studying the spatial "soil arch effect" under overlapping tunnels has become a major research hotspot. Summary of the invention

[0007] The object of the present invention is to provide a movable door device and a test method for measuring soil arching effect of overlapping tunnels. The movable door device and the test method can be used to test the soil arching effect produced by spaces of different widths in overlapping tunnels.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A movable door device for measuring soil arch effect of overlapping tunnels comprises a box, a movable door, a tunnel model and a three-dimensional scanner, wherein the movable door is horizontally arranged in the box, a plurality of soil pressure boxes are arranged on the movable door, the space enclosed by the upper surface of the movable door and the box is used to accommodate soil, and the tunnel model is arranged in the soil; the movable door can move; the movement of the movable door can cause the soil to collapse, and the soil pressure boxes can measure the vertical soil pressure of the soil; the three-dimensional scanner is arranged in the box and below the movable door, and the three-dimensional scanner can measure the arch axis of the soil forming the soil arch effect.

[0010] Furthermore, in the above-mentioned movable door device, the box body includes a front plate, a rear plate, a left plate and a right plate, and the front plate, the left plate, the rear plate and the right plate are sequentially connected to form a cubic structure with upper and lower openings; preferably, the movable door includes two partitions, and the two partitions are placed side by side in the box body, and both of the partitions are movable; preferably, 21 soil pressure boxes are arranged on the upper surface of each partition.

[0011] Furthermore, in the above-mentioned movable door device, sliding devices are provided at the front and rear ends of the two partitions, and the sliding devices are located on the lower surface of the partitions; the sliding devices include slide rails, pulleys and connecting shafts, the slide rails are connected to the partitions, and multiple connecting shafts are provided on the inner side walls of the front plate and the inner side walls of the rear plate, each connecting shaft is sleeved with a pulley, and the pulley and the connecting shaft are rotatably connected; the pulley is in contact with the slide rail, and the slide rail can move on the pulley, thereby allowing the two partitions to undergo relative displacement.

[0012] Furthermore, in the above-mentioned movable door device, the left plate and the right plate are both provided with openings, and the openings respectively correspond to one side of the two partitions, and part or all of one partition can be moved out of the box body through the opening of the left plate; part or all of the other partition can be moved out of the box body through the opening of the right plate.

[0013] Furthermore, in the above-mentioned movable door device, a rubber ring is provided on the pulley; a rotating bearing is provided inside the pulley, and the rotating bearing is sleeved on the connecting shaft; preferably, each of the sliding devices is provided with more than or equal to 5 pulleys.

[0014] Furthermore, in the above-mentioned movable door device, the box body is made of organic glass, preferably, the box body is made of acrylic board; preferably, the movable door is made of acrylic board.

[0015] Furthermore, in the above-mentioned movable door device, the slide rail on the partition is arranged along the width direction of the partition, and the two slide rails on the partition are located on a plane at the same height; the slide rail is fixed to the bottom of the partition by bolts.

[0016] Furthermore, in the above-mentioned movable door device, the length L1 of the box body is 1m, the width L2 of the box body is 0.8m, and the height H1 of the box body is 1.3m; the vertical distance H2 between the movable door and the bottom of the box body is 0.3m, the length of the two partitions is half of the length of the box body, the width is equal to the width of the box body, and the thickness H3 is 0.03m.

[0017] On the other hand, a method for conducting a test using the above-mentioned movable door device is provided, comprising the following steps:

[0018] 1) Place the movable door device on a level and flat ground, and close the two partitions together without leaving any gap in between;

[0019] 2) Fill the box with soil in layers and bury the tunnel model in the soil;

[0020] 3) After the soil shows soil arching effect, record the reading of each soil pressure box;

[0021] 4) Pull the handles of the two partitions respectively to move the two partitions to the left and right sides of the box, thereby increasing the distance between the two partitions. After part of the soil in the box collapses between the two partitions and remains stable, record the reading of each soil pressure box, turn on the 3D scanner, and accurately measure the arch axis of the soil arch effect formed by the soil;

[0022] 5) The arch axis measured by the 3D scanner is imported into the computer, and the soil arch effect law of the space where the overlapping tunnel model is located in the box is analyzed through the arch axis and the readings of the earth pressure box.

[0023] Furthermore, in the above method, the following steps are included between step 4) and step 5):

[0024] Pull the handles of the two partitions again, slowly separate the two partitions, and let the soil collapse again. After waiting for the soil to collapse, record the readings of the soil pressure boxes at different positions at this time, and use a three-dimensional scanner to scan the axis of the newly formed soil arch to complete the simulation of the secondary "soil arch effect"; preferably, in step 2), when filling the soil in layers, the soil is filled in three layers, and the filling interval time of two adjacent layers of the soil is more than 1 hour. After the box is filled, let it stand for one day; preferably, in step 2), only the space where the tunnel model is located is filled with soil.

[0025] It can be seen from the analysis that the present invention discloses a movable door device and a test method for measuring the soil arch effect of overlapping tunnels. By setting a tunnel model in the soil, installing a soil pressure box on the partition, and using a three-dimensional scanner to accurately measure the arch axis that forms the soil arch effect, the spatial "soil arch effect" of the overlapping tunnel can be simulated. In addition, the present invention also provides a sliding device, and at the same time installs a pulley track on the partition, so that the two partitions can slide freely, thereby changing the width between the two partitions, and realizing the spatial soil arch effect test of overlapping tunnels with different widths. It is also possible to simulate the secondary soil arch effect formed by changing the width between the partitions again after the soil arch is formed and stabilized. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0027] Figure 1 It is a schematic diagram of the three-dimensional structure of an embodiment of the present invention.

[0028] Figure 2 It is a schematic diagram of the main structure of an embodiment of the present invention.

[0029] Figure 3 It is a right view structural schematic diagram of an embodiment of the present invention.

[0030] Figure 4 Schematic diagram of the detailed structure of the pulley and track according to an embodiment of the present invention

[0031] Description of reference numerals: 1 box body; 11 front plate; 12 rear plate; 13 left plate; 14 right plate; 15 bottom plate; 2 movable door; 21 partition plate; 3 tunnel model; 4 earth pressure box; 5 soil body; 6 three-dimensional scanner; 7 sliding device; 71 slide rail; 72 pulley; 73 coupling; 8 opening; 9 handle;

[0032] L1: Length of the box; L2: Width of the box; H1: Height of the box; H2: Vertical distance between the movable door and the bottom plate; H3: Thickness of the partition. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments. Each example is provided by way of explanation of the present invention and does not limit the present invention. In fact, it will be clear to those skilled in the art that modifications and variations may be made in the present invention without departing from the scope or spirit of the present invention. For example, a feature shown or described as a part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desired that the present invention encompasses such modifications and variations within the scope of the appended claims and their equivalents.

[0034] In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and do not require that the present invention must be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention. The terms "connected", "connected" and "set" used in the present invention should be understood in a broad sense. For example, they can be fixedly connected or detachably connected; they can be directly connected or indirectly connected through intermediate components. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0035] like Figures 1 to 4 As shown, according to an embodiment of the present invention, a movable door device for measuring soil arch effect of overlapping tunnels is provided, comprising a box 1, a movable door 2, a tunnel model 3 and a three-dimensional scanner 6, wherein the movable door 2 is horizontally arranged in the box 1, a plurality of soil pressure boxes 4 are arranged on the movable door 2, the space enclosed by the upper surface of the movable door 2 and the box 1 is used to accommodate soil 5, and the tunnel model 3 is arranged in the soil 5; the movable door 2 can move and can pass through the side wall of the box 1 to partially or completely move out of the box 1; the movement of the movable door 2 can cause the soil 5 to collapse, and the soil pressure box 4 can measure the vertical soil pressure of the soil 5; the three-dimensional scanner 6 is arranged in the box 1 and below the movable door 2, and the three-dimensional scanner 6 can measure the arch axis of the soil 5 forming the soil arch effect. The parameters of the arch axis include the load on the partition 21 and the height of the arch axis of the soil arch formed when the partition 21 is spaced at different distances.

[0036] The part of the box body 1 located below the movable door 2 can be called a base, and the three-dimensional scanner 6 is fixed in the middle of the bottom of the base. The three-dimensional scanner 6 is preferably a laser three-dimensional scanner, which can realize non-contact measurement.

[0037] Specifically, the soil 5 in the box 1 can be soil of different types and parameters, and the soil arch effect generated by the soil 5 of different types and parameters can be simulated. The movable door 2 is moved multiple times to make the soil 5 in the box 1 collapse. After each collapse of the soil 5 and after the soil 5 reaches equilibrium and stability, the soil arch effect is generated in the soil 5. The soil pressure box 4 is used to measure the vertical soil pressure of the soil 5 in the current state, and the three-dimensional scanner 6 is used to measure the arch axis of the soil 5 forming the soil arch effect in the current state. The soil pressure data and the arch axis can be used to analyze the law of the soil arch effect in the space where the tunnel model 3 in the box 1 is located.

[0038] Furthermore, if Figure 1 As shown, the box body 1 includes a front plate 11, a rear plate 12, a left plate 13 and a right plate 14, which are connected in sequence to form a cubic structure with upper and lower openings. The present invention is to study the "soil arch effect" in a semi-infinite soil body, and the box body 1 with a cubic structure is a simplification of the semi-infinite soil body; preferably, the movable door 2 includes two partitions 21, which are arranged side by side in the box body 1, and the two partitions 21 can move. Moving the two partitions 21 can cause the two partitions 21 to have a relative displacement. When the two partitions 21 are moved When relative displacement occurs, there is a gap between the two partitions 21, and the soil 5 can collapse through the gap between the two partitions 21; preferably, 21 soil pressure boxes 4 are arranged on the upper surface of each partition 21, and the 21 soil pressure boxes are arranged in a rectangular array. There are 7 rows of soil pressure boxes 4 on the partition 21 from the front end to the rear end, and each row is provided with 3 soil pressure boxes 4. The 21 soil pressure boxes are evenly distributed on the partition 21, so that the size of the soil pressure at different positions can be measured. The spacing between the soil pressure boxes 21 should be determined according to the size of the soil pressure box 21 itself. The number of soil pressure boxes 4 is determined according to the size of the soil pressure box 4 and the need to measure the soil pressure at different longitudinal positions. If there are too many soil pressure boxes 4, there will be no place to place them, and if there are too few soil pressure boxes 4, the soil pressure at different longitudinal positions cannot be measured. The two partitions 21 that can move toward each other form a movable door, and both partitions 21 can move. Due to the size limitation of the box 1 itself, if one partition 21 is fixed, only one partition 21 can be moved, which will cause bias and fail to achieve the test purpose. Two partitions 21 that can both move can make the two partitions 21 move relative to the center of the box. By moving the partition 21 and changing the distance between the two partitions 21, a "soil arch effect" and a secondary "soil arch effect" are formed, thereby realizing a spatial "soil arch effect" test of different widths of overlapping tunnels.

[0039] Furthermore, if Figure 2As shown, the box body 1 also includes a bottom plate 15, which is connected to the bottom end of the front plate 11, the bottom end of the rear plate 12, the bottom end of the left plate 13 and the bottom end of the right plate 14. The three-dimensional scanner 6 is arranged on the bottom plate 15. Such an arrangement can facilitate the movement of the entire movable door device and simplify the experimental procedure.

[0040] The present invention sets a tunnel model 3 in the soil 5, uses the tunnel model 3 to simulate the existing (original) tunnel, installs the soil pressure box 4 on the partition 21, and uses the three-dimensional scanner 6 to accurately measure the arch axis of the formed soil arch, so as to simulate the spatial "soil arch effect" of the overlapping tunnel. The movement of the two partitions 21 can change the width of the gap between the two partitions 21, and realize the spatial "soil arch effect" test of different widths of the overlapping tunnel. It is also possible to simulate the secondary "soil arch effect" formed by changing the width of the gap between the partitions 21 again after the soil arch is formed and stabilized.

[0041] Furthermore, if Figure 1 As shown, the length of the box 1 (the length of the front plate 11 and the rear plate 12) L1 is 1m, the width of the box 1 (the length of the left plate 13 and the right plate 14) L2 is 0.8m, and the height H1 of the box 1 is 1.3m; the vertical distance H2 between the movable door 2 (partition 21) and the bottom of the box 1 is 0.3m, the length of the two partitions 21 is half of the length of the box 1, the width is equal to the width of the box 1, and the thickness H3 is 0.03m. The size of the above movable door device is determined according to the similarity ratio of the similar model test, and the size meets the similarity principle.

[0042] Furthermore, in order to visually observe the soil arch effect, the box 1 is made of organic glass, preferably, the box 1 is made of acrylic board. Preferably, the movable door 2 is made of acrylic board, which can effectively reduce the friction between the soil 5 and the movable door 2 and reduce the influence of the boundary effect.

[0043] Furthermore, in order to enable the two partitions 21 to move stably and slowly, sliding devices 7 are provided at both the front and rear ends of the two partitions 21. Figure 3 and Figure 4As shown, the sliding device 7 is located on the lower surface of the partition 21; the sliding device 7 includes a slide rail 71, a pulley 72 and a coupling 73. The slide rail 71 is connected to the partition 21. A plurality of couplings 73 are provided on the inner side wall of the front plate 11 and the inner side wall of the rear plate 12. Each coupling 73 is sleeved with a pulley 72, and the pulley 72 and the coupling 73 are rotatably connected; the pulley 72 is in close contact with the slide rail 71, and the slide rail 71 can move on the pulley 72, thereby enabling the two partitions 21 to move relative to each other. The two partitions 21 can slide freely, thereby changing the width of the gap between the two partitions 21, and realizing the spatial "soil arch effect" test of different widths of overlapping tunnels. It can also simulate the secondary "soil arch effect" formed by changing the width of the gap between the partitions 21 again after the soil arch is formed and stabilized.

[0044] Furthermore, a rubber ring is sleeved on the pulley 72, and the setting of the rubber ring can increase the friction between the pulley 72 and the slide rail 71, and prevent the pulley 72 and the slide rail 71 from rotating relative to each other and affecting the sliding effect of the partition 21; a rotating bearing is arranged inside the pulley 72, and the rotating bearing is sleeved on the connecting shaft 73; preferably, each sliding device 7 is provided with more than or equal to 5 pulleys 72. The number of pulleys 72 can be adjusted, but the number should be greater than or equal to 5. Since in this test, the disturbance of the soil 5 should be controlled as much as possible to prevent collapse due to excessive disturbance without the occurrence of the "soil arch effect", increasing the number of pulleys 72 can increase the stability of the partition 21 when it moves and thus avoid the disturbance of the soil 5. Preferably, the radius of the pulley 72 is 0.02m. A smaller pulley 72 is selected, and the stability of the partition 21 when it moves is increased by adjusting the number of pulleys 72, reducing the disturbance to the soil 5. And the pulley 72 with a radius of 0.02m is a common size, which is convenient for purchase and configuration.

[0045] Furthermore, the slide rail 71 on the partition 21 is arranged along the width direction of the partition 21, that is, the slide rail 71 is arranged on the lower surface of the front and rear ends of the partition 21, and the slide rail 71 extends from the left side of the partition 21 to the right side of the partition 21. The length of the slide rail 71 should be equal to the side length between the left and right ends of the partition 21, and the partition 21 and the slide rail 71 are connected as a whole. The two slide rails 71 on the partition 21 are located on a plane at the same height. Such an arrangement can prevent the situation where the filling height of the soil body 5 is different, which affects the occurrence of the soil arch effect. The slide rails 71 are fixed to the bottom of the partition 21 by bolts respectively. Such an arrangement can make the connection between the slide rail 71 and the partition 21 more firm.

[0046] Furthermore, if Figure 1As shown, both the left plate 13 and the right plate 14 are provided with an opening 8, and the shape of the opening 8 is the same as the shape of one side of the partition 21. The opening 8 on the left plate 13 and the opening 8 on the right plate 14 respectively correspond to one side of the two partitions 21. A handle 9 is provided on one side of the partition 21 located at the opening 8 on the left plate 13, and a handle 9 is provided on one side of the other partition 21 located at the opening 8 on the right plate 14. Pulling the handles 9 on the two partitions 21 respectively can cause the two partitions 21 to be relatively displaced, and part or all of one partition 21 can be moved out of the box body 1 through the opening 8 of the left plate 13; part or all of the other partition 21 can be moved out of the box body 1 through the opening 8 of the right plate 14.

[0047] Furthermore, in the soil body 5, the placement position and the inclination angle of the tunnel model 3 can be adjusted according to the test conditions.

[0048] In the technical solution of the present invention, the tunnel model 3 is used to simulate the existing (original) tunnel, and a new tunnel is built at the position where the "soil arch effect" is generated by pulling apart the two partitions 21. At this time, the existing (original) tunnel and the new tunnel form an overlapping tunnel. In the test of the present invention, the soil arch effect of the new tunnel is studied in the case of an existing tunnel. Placing a tunnel model 3 can measure the soil arch effect formed by the overlapping tunnel.

[0049] The present invention also discloses a method for conducting a test using the above-mentioned movable door device, comprising the following steps:

[0050] 1) Place the movable door device on a level and flat ground, and close the two partitions 21 together without leaving a gap in between;

[0051] 2) Fill the box 1 with soil 5 in layers and bury the tunnel model 3 in the soil 5. The soil 5 can be soil 5 of different types and parameters to simulate the soil arch effect under different soil 5 conditions. After selecting the soil 5 to be tested, fill the box 1 with soil 5 by layer filling method and bury the tunnel model 3 in the soil 5. The layer filling method is to load the soil 5 into the box 1 in layers, and the loaded soil 5 needs to be leveled for each layer. When filling the soil 5 in layers, the soil 5 is filled in three layers, and the filling interval time between two adjacent layers of soil 5 is more than 1 hour. Such a setting can make the soil 5 filling more dense, closer to the actual situation, and is conducive to the "soil arch effect" of the soil 5. Among them, when the soil 5 is filled in layers, only the space where the tunnel model 3 is located is filled with the soil 5. In order to reduce the influence of the lateral soil arch effect, the test of the present invention is based on the upper half of the shield tunnel, that is: when filling the soil 5, sand is filled in the bottom layer of the soil 5 (the upper surface of the partition 21), and the sand filling needs to be dense.

[0052] 3) After step 2), let it stand for one day until the soil 5 shows soil arching effect, and then record the reading of each soil pressure box 4;

[0053] 4) Pull the handles 9 of the two partitions 21 respectively, so that the two partitions 21 move to the left and right sides of the box 1 and then remain stationary, thereby increasing the distance between the two partitions 21. After part of the soil 5 in the box 1 collapses between the two partitions 21 and remains stable, the soil 5 in the box 1 presents a soil arch effect. Record the reading of each soil pressure box 4, turn on the three-dimensional scanner 6, and accurately measure the arch axis of the soil 5 forming the soil arch effect, thereby completing the simulation of the single-space "soil arch effect";

[0054] 5) Pull the handles 9 of the two partitions 21 again, slowly separate the partitions 21, and the soil 5 collapses again. After waiting for the soil 5 to collapse, record the readings of the soil pressure box 4 at different positions at this time, and use the three-dimensional scanner 6 to scan the newly formed soil arch axis to complete the simulation of the secondary "soil arch effect".

[0055] 6) Repeat step 5) for multiple tests to obtain results of different widths. When the distance between the two partitions 21 reaches a width at which the soil 5 cannot form a stable soil arch effect, the test ends.

[0056] 7) The arch axis measured by the three-dimensional scanner 6 is imported into the computer, and the soil arch effect law of the space where the overlapping tunnel model 3 in the box body 1 is located is analyzed through the arch axis and the readings of the earth pressure box 4.

[0057] In step 4) to step 6), the distance that the two partitions 21 move each time is determined according to the properties of the soil 5 itself and the limit conditions of the test. A preliminary test can be conducted before the formal test to obtain the maximum width of the partition that can be stable under the soil 5 condition, and then the distance of each movement is given, and the distance of each movement is ensured to be equal in the test.

[0058] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0059] A movable door device for measuring soil arching effect of overlapping tunnels comprises a box 1, a movable door 2, a tunnel model 3 and a three-dimensional scanner 6. The movable door 2 is provided with a plurality of soil pressure boxes 4, and the space enclosed by the upper surface of the movable door 2 and the box 1 is used to accommodate soil 5, in which the tunnel model 3 is provided.

[0060] The present invention can simulate the spatial "soil arch effect" of overlapping tunnels by setting a tunnel model 3 in the soil 5, installing an earth pressure box 4 on the partition 21, and accurately measuring the arch axis forming the soil arch effect with the help of a three-dimensional scanner 6. In addition, the present invention also provides a sliding device 7, and at the same time installs a pulley 72 track on the partition 21, so that the two partitions 21 can slide freely, thereby changing the width of the gap between the two partitions 21, and realizing the spatial "soil arch effect" test of different widths of overlapping tunnels. It can also simulate the secondary "soil arch effect" formed by changing the width of the gap between the partitions 21 again after the soil arch is formed and stabilized.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A movable door device for measuring soil arching effect in overlapping tunnels, characterized in that: It includes a box, a movable door, a tunnel model and a 3D scanner, among which: The movable door is horizontally arranged in the box body, a plurality of soil pressure boxes are arranged on the movable door, the space enclosed by the upper surface of the movable door and the box body is used to accommodate soil, and the tunnel model is arranged in the soil body; The movable door is movable; The movement of the movable door can cause the soil to collapse, and the soil pressure box can measure the vertical soil pressure of the soil; The three-dimensional scanner is arranged in the box and below the movable door, and the three-dimensional scanner can measure the arch axis of the soil arch effect formed by the soil body; The box body comprises a front plate, a rear plate, a left plate and a right plate, wherein the front plate, the left plate, the rear plate and the right plate are sequentially connected to form a cubic structure with upper and lower openings; The movable door comprises two partitions, which are arranged side by side in the box, and both of them are movable; The front and rear ends of the two partitions are both provided with sliding devices, and the sliding devices are located on the lower surface of the partitions; The sliding device comprises a slide rail, a pulley and a coupling, wherein the slide rail is connected to the partition, a plurality of couplings are arranged on the inner side wall of the front plate and the inner side wall of the rear plate, each coupling is sleeved with a pulley, and the pulley is rotatably connected to the coupling; The pulley is in contact with the slide rail, and the slide rail can move on the pulley, thereby enabling the two partitions to move relative to each other.

2. The movable door device according to claim 1, characterized in that: 21 soil pressure cells are arranged on the upper surface of each partition.

3. The movable door device according to claim 1, characterized in that: The left plate and the right plate are both provided with openings, and the openings correspond to one side of the two partitions respectively. Part or all of one partition can be moved out of the box through the opening of the left plate; part or all of the other partition can be moved out of the box through the opening of the right plate.

4. The movable door device according to claim 1, characterized in that: A rubber ring is sleeved on the pulley; A rotating bearing is arranged inside the pulley, and the rotating bearing is sleeved on the connecting shaft; Each of the sliding devices is provided with greater than or equal to 5 pulleys.

5. The movable door device according to claim 1, characterized in that: The box body is made of organic glass.

6. The movable door device according to claim 5, characterized in that: The box body is made of acrylic board; the movable door is made of acrylic board.

7. The movable door device according to claim 1, characterized in that: The slide rail on the partition is arranged along the width direction of the partition, and the two slide rails on the partition are located on a plane at the same height; the slide rail is fixed to the bottom of the partition by bolts.

8. The movable door device according to claim 1, characterized in that: The length L1 of the box is 1m, the width L2 of the box is 0.8m, and the height H1 of the box is 1.3m; the vertical distance H2 between the movable door and the bottom of the box is 0.3m, the length of the two partitions is half of the length of the box, the width is equal to the width of the box, and the thickness H3 is 0.03m.

9. A method for testing a movable door device according to any one of claims 1 to 8, characterized in that: The steps include: 1) Place the movable door device on a level and flat ground, and close the two partitions together without leaving any gap in between; 2) Fill the box with soil in layers and bury the tunnel model in the soil; 3) After the soil shows soil arching effect, record the reading of each soil pressure box; 4) Pull the handles of the two partitions respectively to move the two partitions to the left and right sides of the box, thereby increasing the distance between the two partitions. After part of the soil in the box collapses between the two partitions and remains stable, record the reading of each soil pressure box, turn on the 3D scanner, and accurately measure the arch axis of the soil arch effect formed by the soil; 5) The arch axis measured by the 3D scanner is imported into the computer, and the soil arch effect law of the space where the overlapping tunnel model is located in the box is analyzed through the arch axis and the readings of the earth pressure box.

10. The method according to claim 9, characterized in that The following steps are also included between step 4) and step 5): Pull the handles of the two partitions again, slowly separate the two partitions, and the soil collapses again. After waiting for the soil to collapse, record the readings of the soil pressure boxes at different positions at this time, and use a 3D scanner to scan the axis of the newly formed soil arch to complete the simulation of the secondary "soil arch effect"; In the step 2), when the soil is filled in layers, the soil is filled in three layers, and the interval between filling two adjacent layers of the soil is more than 1 hour. After the box is filled, it is left to stand for one day; In the step 2), only the space where the tunnel model is located is filled with soil.

Images