A measurement system and method for measuring the spatial soil arch caused by the excavation of a model tunnel

Abstract

The present invention belongs to the technical field of civil engineering model tests. Specifically, the present invention relates to a measurement system and a measurement method for a spatial soil arch caused by the excavation of a model tunnel. The measurement system includes a box body, a tunnel model, a supporting device, and a three-dimensional scanner; a rectangular slot is provided at the bottom of the box body; the tunnel model is sealed at the rectangular slot, and the bottom abuts against the supporting device. The tunnel model and the box body form a space for bearing soil; when the tunnel model is moved, the soil collapses from the rectangular slot; the supporting device abuts against the tunnel model below the tunnel model; the three-dimensional scanner is located below the box body. The measurement method is implemented based on the measurement system. The present invention can accurately and automatically measure the arch axis of the soil arch effect in the spatial state, so as to better reflect the internal law of the soil arch effect and master the influence of the soil arch effect on the construction of shield tunnels.

Description

Technical Field

[0001] The present invention belongs to the technical field of civil engineering model tests. Specifically, the present invention relates to a measurement system and a measurement method for a spatial soil arch caused by model tunnel excavation. Background Art

[0002] Tunnel engineering is an important development direction in the field of civil engineering today. Against the background of the continuous increase in tunnel cross-section and burial depth, carrying out tunnel model tests has a significant impact on the development of tunnel construction technology. The study of load action laws is an important part of tunnel engineering design. How to accurately measure the arch axis formed after tunnel excavation is an important issue in the study of load action.

[0003] As early as in 1884, the British scientist Roberts first discovered the "granary effect", that is: the force borne by the bottom surface of the granary reaches the maximum value and remains unchanged after the grain is piled up to a certain extent, which is the so-called soil arch effect. In 1943, Terzaghi confirmed the existence of the soil arch effect in the field of soil mechanics through the famous "movable door" test, and based on the description of the stress distribution of the soil arch, obtained the conditions for the existence of the soil arch effect.

[0004] After tunnel excavation, the load acting on the tunnel support structure by the surrounding rock is called the surrounding rock pressure, which is the main load source of the tunnel support structure. Under the action of load or self-weight, the soil undergoes compression and deformation, resulting in uneven settlement, so that the soil particles produce a mutual "wedging" effect, and thus an "arch effect" is generated 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. Accurately measuring the arch axis in the test plays a crucial role in the study of the "arch effect" of the soil. Reasonably using the soil arch effect can make the stress redistribution of the soil develop in a direction beneficial to the project and make full use of the anti-deformation ability of the soil itself.

[0005] However, at present, it only stays at the macroscopic observation of the soil arch effect. Most of them only observe the existence of the "soil arch effect" with the naked eye without accurately measuring its arch axis, and cannot well reflect the internal law of the "soil arch effect", nor can they study the influence of the "soil arch effect" on the load borne by the tunnel. Moreover, most test devices only observe the "soil arch effect" on the plane, which is only a plane strain problem, and there is little research on the "soil arch effect" in the spatial state. Summary of the Invention

[0006] The present invention provides a measurement system and a measurement method for a spatial soil arch caused by model tunnel excavation, which can accurately measure the arch axis of the "soil arch effect" in the spatial state, so as to be able to study the "soil arch effect" in the spatial state. The technical solution is as follows:

[0007] A measurement system for the spatial soil arch caused by the excavation of a model tunnel, comprising: a box body, a tunnel model, a supporting device and a 3D scanner; a rectangular slot is provided at the bottom of the box body; the tunnel model is sealed at the rectangular slot, and the bottom abuts against the supporting device, and the tunnel model and the box body form a space for carrying soil; when the tunnel model is moved, the soil collapses from the rectangular slot; the supporting device abuts against the tunnel model below the tunnel model for supporting the tunnel model; the 3D scanner is located below the box body for measuring the arch axis formed after simulating the construction of a shield tunnel.

[0008] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the supporting device comprises a base and rollers; the rollers are installed on the base, and the rollers are rotatably connected to the base.

[0009] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: there are multiple rollers, which are evenly distributed along the length direction of the rectangular slot, and the axis of the rollers is perpendicular to the length direction of the rectangular slot.

[0010] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: a rubber layer is provided on the circumferential surface of the rollers.

[0011] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: further comprising: a pulling device, which is connected to the tunnel model for pulling the tunnel model.

[0012] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the pulling device is any one of a hydraulic cylinder, a pneumatic cylinder, a linear motor, a lead screw transmission device, a rope, and a handle.

[0013] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the pulling device comprises a coupling shaft, a connecting rod, a pull rod and a lever; the coupling shaft is located inside the tunnel model and is fixedly connected to the tunnel model; the connecting rod is located inside the tunnel model, and one end is fixedly connected to the coupling shaft; the pull rod is located outside the tunnel model, one end of the pull rod is connected to the other end of the connecting rod, and the other end of the pull rod is connected to the lever.

[0014] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the box body comprises a front plate, a left plate, a rear plate, a right plate connected in sequence, and a bottom plate respectively connected to the front plate, the left plate, the rear plate, and the right plate, and the rectangular slot is located in the middle of the bottom plate.

[0015] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the material of the box body is transparent organic glass.

[0016] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the bottom plate includes a first bottom plate and a second bottom plate, and the first bottom plate and / or the second bottom plate are slidably arranged below the front plate, the left plate, the rear plate, and the right plate.

[0017] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the axis of the tunnel model and the upper surface of the bottom plate are in the same plane.

[0018] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the material of the tunnel model is smooth acrylic material.

[0019] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the lens of the 3D scanner is directly below the symmetric center of the rectangular slot.

[0020] The measurement system for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: the 3D scanner is a laser 3D scanner.

[0021] A measurement method for the spatial soil arch caused by the excavation of a model tunnel, the measurement method for the spatial soil arch caused by the excavation of the model tunnel is realized based on the measurement system for the spatial soil arch caused by the excavation of the model tunnel, and includes:

[0022] Step 1: Place the tunnel model at the rectangular slot, and use the supporting device to support the tunnel model at the bottom of the tunnel model so that the tunnel model completely blocks the rectangular slot;

[0023] Step 2: Fill the space of the bearing soil body formed by the box body and the tunnel model with soil, and let it stand still after the soil filling is completed;

[0024] Step 3: Turn on the 3D scanner, and slowly separate the tunnel model from the box body until the tunnel model is completely separated from the box body;

[0025] Step 4: Output the measurement result of the 3D scanner as a CAD drawing to obtain the arch axis of the spatial soil arch effect at different test stages.

[0026] The measurement method for the spatial soil arch caused by the excavation of the model tunnel as described above is further preferably: in Step 1, when placing the tunnel model, make the axis of the tunnel model and the upper surface of the bottom plate of the box body be in the same plane.

[0027] The method for measuring spatial soil arch caused by model tunnel excavation as described above is further preferably: in the step 2, soils of different types and parameters are filled in layers, each layer is leveled after filling, and the next layer is filled after being left to stand for not less than 1 hour, and after all the soil is filled, the soil is left to stand for 24 to 36 hours.

[0028] The method for measuring spatial soil arch caused by model tunnel excavation as described above is further preferably as follows: in step three, when the tunnel model slowly leaves the box, if the soil is unstable, the movement of the tunnel model needs to be stopped until the soil is stable and the tunnel model is moved again.

[0029] It can be seen from the analysis that compared with the prior art, the advantages and beneficial effects of the present invention are:

[0030] The present invention can accurately and automatically measure the arch axis of the soil arch effect in a spatial state, solving the technical problem that it is difficult to accurately measure the arch axis of the soil arch effect in the existing experiments, thereby better reflecting the inherent law of the soil arch effect and understanding the influence of the soil arch effect on the shield tunnel construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of the measurement system of the spatial soil arch caused by the excavation of the model tunnel of the present invention.

[0032] Figure 2 It is a cross-sectional view when cutting perpendicularly to the axial direction of the tunnel model at a position where a three-dimensional scanner is installed.

[0033] Figure 3 This is a schematic diagram of the connection relationship of the tunnel model.

[0034] In the figure: 1- tunnel model; 2- connecting rod; 3- connecting shaft; 4- rolling shaft; 5- box; 6- base; 7- 3D scanner; 8- pulling rod; 9- lever. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] 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 should not be understood as limitations on the present invention. The terms "connected" and "connected" used in the present invention should be understood in a broad sense. For example, they can be fixed connections or detachable connections; 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.

[0037] Please refer to Figures 1 to 3 , Figure 1 It is a structural schematic diagram of a measurement system for spatial soil arching caused by excavation of a model tunnel of the present invention; Figure 2 It is a cross-sectional view when the tunnel model is cut perpendicularly to the axis direction at a position where a three-dimensional scanner is provided; Figure 3 is a schematic diagram of the connection relationship of the tunnel model. Figure 2 In the figure, the lower (inner) semicircle represents the outer diameter of the tunnel model, the irregular arc above the semicircle is the contour of the soil surface formed by the soil arch effect, and the empty part between the semicircle and the irregular arc above the semicircle is the volume of soil collapse.

[0038] like Figure 1 and Figure 2 As shown, the present invention provides a measurement system for spatial soil arch caused by model tunnel excavation, which mainly includes a box 5, a tunnel model 1, a supporting device and a three-dimensional scanner 7. A rectangular groove is provided at the bottom of the box 5, and the tunnel model 1 is blocked at the rectangular groove, and the bottom is against the supporting device. The tunnel model 1 and the box 5 form a space for bearing the soil. When the tunnel model 1 is moved, the soil collapses from the rectangular groove. The supporting device is against the tunnel model 1 below the tunnel model 1, playing a role of supporting the tunnel model 1. The three-dimensional scanner 7 is located below the box 5, and is used to measure the arch axis formed after the construction of the simulated shield tunnel.

[0039] Specifically, the tunnel model 1 of the present invention is blocked at the rectangular slot of the box body 5. Initially, it can completely block the rectangular slot, thereby forming a space for bearing soil. The supporting device is located below the tunnel model 1 and abuts against the tunnel model 1, capable of supporting the tunnel model 1. The 3D scanner 7 is located below the tunnel model 1 and can scan and record the changes in the shape structure of the soil caused by the movement of the tunnel model 1. As the tunnel model 1 gradually disengages along the length direction of the rectangular slot (the length direction of the rectangular slot is parallel to the axis of the tunnel model 1, and the width direction of the rectangular slot is perpendicular to the axis direction of the tunnel model 1), a gap is generated between the tunnel model 1 and the rectangular slot in the width direction of the rectangular slot. As the gap increases, the soil above the tunnel model 1 gradually collapses from the gap, thereby simulating the process of shield tunnel construction. During this period, the 3D scanner 7 can scan and record the outer contour of the soil above the tunnel model 1, thereby measuring the arch axis formed after simulating the shield tunnel construction. The present invention can accurately and automatically measure the arch axis of the soil arch effect in the spatial state, thereby better reflecting the internal law of the soil arch effect and mastering the influence of the soil arch effect on shield tunnel construction.

[0040] Further, for the convenience of the sliding of the tunnel model 1, as Figure 1 and Figure 3 shown, the supporting device of the present invention includes a base 6 and rollers 4. The base 6 is a cavity structure without a top surface and is in a cuboid shape. The rollers 4 are installed on the left and right side walls of the base 6, and the rollers 4 are rotatably connected to the base 6. During the test, the box body 5 is placed on the base 6. At this time, the tunnel model 1 can just be located on the rollers 4. Using the rollers 4 to support the tunnel model 1 can reduce the resistance suffered by the tunnel model 1 when it disengages from the box body 5 and facilitate the smooth sliding of the tunnel model 1. Preferably, three holes for installing the rollers 4 are respectively opened on the left and right side walls of the base 6. The number of rollers 4 is three, and they are evenly distributed along the length direction of the rectangular slot. The axis of the rollers 4 is perpendicular to the length direction of the rectangular slot, so as to support the smooth disengagement of the tunnel model 1 during the entire disengagement process of the tunnel model 1, making the test closer to the real state.

[0041] Further, to ensure the smoothness of the tunnel model 1 during sliding, as Figure 3 shown, in the present invention, a rubber layer is provided on the circumferential surface of the roller 4, which can increase the frictional resistance of the rolling friction between the tunnel model 1 and the roller 4, prevent the roller 4 from slipping on the tunnel model 1, and ensure the smooth sliding of the tunnel model 1. When installing the rubber layer, a rubber layer can be installed on the entire circumferential surface of the roller 4, or a rubber ring can be installed on the circumferential surface of the roller 4 in contact with the tunnel model 1 as the rubber layer.

[0042] Further, for the convenience of applying a force to the sliding of the tunnel model 1, asFigure 1 and Figure 3 As shown in Figure 3 , the present invention further includes a pulling device, which is connected to the tunnel model 1 and can pull the tunnel model 1, so that the tunnel model 1 slowly disengages from the box body 5. In terms of scheme selection, the pulling device can be an automatic force-applying device such as a hydraulic cylinder, a pneumatic cylinder, or a linear motor to apply a force to the tunnel model 1; the pulling device can also be a lead screw transmission device. A ball is provided on the tunnel model 1, and the box body 5 or the base 6 is selected as the support point of the lead screw, and the tunnel model 1 is slowly slid by shaking the lead screw; the pulling device can also be a device such as a rope or a handle for providing an external force application point, and the tunnel model 1 is slowly slid by manual pulling.

[0043] Furthermore, as a preferred scheme, the pulling device of the present invention includes a coupling shaft 3, a connecting rod 2, a pull rod 8, and a lever 9. The coupling shaft 3 is located inside the tunnel model 1 and is fixedly connected to the tunnel model 1 by means of bolt connection. The connecting rod 2 is located inside the tunnel model 1, one end is fixedly connected to the coupling shaft 3 by means of bolt connection, and the other end is connected to the pull rod 8. The connecting rod 2 is hollow inside and has threads inside. The pull rod 8 is located outside the tunnel model 1 and has threads on the surface. One end of the pull rod 8 is connected to the connecting rod 2, and the other end is connected to the lever 9. After the lever 9 is rotated, the pull rod 8 also rotates accordingly. At this time, the external thread on the surface of the pull rod 8 is tightly combined with the internal thread of the connecting rod 2, so that the connecting rod 2 can move slowly in a straight line. The other end of the connecting rod 2 is connected to the coupling shaft 3 connected to the tunnel model 1. The coupling shaft 3 moves the tunnel model 1 out at the same time. The advantage of this is that the tunnel model can be moved out of the soil more smoothly and slowly.

[0044] Furthermore, in the implementation scheme of the present invention, a bracket (not shown) can also be provided on the outer circumference of the pull rod 8. The bracket is fixed on the ground or the base 6 and remains relatively stationary with respect to the box body 5. The bracket is connected at the connection with the pull rod 8 through a bearing, so as to ensure that the pull rod 8 only rotates and does not move in a straight line during operation. Furthermore, the lever 9 can be rotated to drive the pull rod 8 to rotate, so as to slowly move the tunnel model 1 out of the soil. As another implementation scheme, the bracket may not be provided during implementation, but at this time, it is necessary to ensure that the pull rod 8 does not move in a straight line during rotation, that is: when the lever 9 is rotated, a pulling force needs to be applied to the lever 9, and the pulling force is along the axis of the pull rod 8 and points to the side away from the pull rod 8.

[0045] Furthermore, as Figure 1As shown in the figure, in the present invention, the box body 5 includes a front plate, a left plate, a rear plate, a right plate connected in sequence, and a bottom plate respectively connected to the front plate, the left plate, the rear plate, and the right plate. The five plates form a cuboid cavity without a top. The rectangular slot is located in the middle of the bottom plate, and the length direction of the rectangular slot is perpendicular to the surface of the front plate. The front plate is provided with holes that fit the outer contour of the circumferential surface of the tunnel model 1. In order to facilitate test operation and intuitive observation of the soil arch effect, the material of the box body 5 of the present invention is transparent organic glass, and the front plate, the left plate, the rear plate, the right plate, and the bottom plate are all made of transparent acrylic plates.

[0046] Further, as Figure 1 shown in the figure, in the present invention, the bottom plate includes a first bottom plate and a second bottom plate. The first bottom plate and / or the second bottom plate are slidably arranged below the front plate, the left plate, the rear plate, and the right plate, so as to be able to adjust the width of the rectangular slot between the two to adapt to tunnel models 1 with different diameters, thereby expanding the application range of the present invention. Specifically, slots are provided at the bottoms of the front plate, the left plate, the rear plate, and the right plate, and the first bottom plate and the second bottom plate are installed in the slots and can slide along the slots.

[0047] Further, in order to reduce the influence caused by the lateral soil arch effect, as Figure 1 and Figure 2 shown in the figure, in the present invention, the axis of the tunnel model 1 is in the same plane as the upper surface of the bottom plate. During the test, only the upper half area of the tunnel model 1 bears the soil body (the upper half area of the tunnel model 1 is filled with dense sand during the test), so as to be able to simulate the influence of the soil arch effect in the vertical direction of the soil body on the shield tunnel during shield tunnel construction. Preferably, the material of the tunnel model 1 is smooth acrylic material, which can reduce the friction between the tunnel model 1 and the overlying soil body and facilitate the detachment of the tunnel model 1.

[0048] Further, in order to facilitate the simulation of the excavation process of the shield tunnel, in the present invention, the external dimensions of the box body 5 are determined according to the similarity ratio of the similar model test considering the actual working conditions, which can reduce the influence of the boundary effect on the test results. The external dimensions of the box body 5 are 1.0m×0.8m×1.0m in length, width, and height, and the thicknesses of the front plate, the left plate, the rear plate, the right plate, and the bottom plate are all not less than 0.1m. The external dimensions of the base 6 are 1.0m×0.8m×0.3m in length, width, and height, and the external dimensions of the tunnel model 1 are a radius of 0.1m and a length of 0.6m. During the test, the tunnel model 1 should be placed in the rectangular slot (between the first bottom plate and the second bottom plate) at the beginning, and then the soil is filled. No hole matching the tunnel model 1 is opened on the rear plate, while a hole matching the tunnel model 1 needs to be opened on the front plate for the tunnel model 1 to be screwed out.

[0049] Further, in order to improve the measurement accuracy of the arch axis formed by the spatial soil arch effect, as Figure 2As shown in the figure, the lens of the three-dimensional scanner 7 of the present invention is located directly below the symmetric center of the rectangular slot. Preferably, the three-dimensional scanner 7 is a laser three-dimensional scanner, which is simple to operate, has high measurement accuracy, and can directly import measurement data into CAD for analysis and processing.

[0050] Meanwhile, as Figures 1 to 3 shown, the present invention also provides a method for measuring the spatial soil arch caused by the excavation of a model tunnel. The method for measuring the spatial soil arch caused by the excavation of a model tunnel is realized based on the measurement system for the spatial soil arch caused by the excavation of a model tunnel, and the steps include:

[0051] Step 1: Place the tunnel model 1 at the rectangular slot, and use a supporting device to support the tunnel model 1 at the bottom of the tunnel model 1 so that the tunnel model 1 completely blocks the rectangular slot.

[0052] Among them, when placing the tunnel model 1, make the axis of the tunnel model 1 and the upper surface of the bottom plate of the box body 5 be in the same plane, which can reduce the influence caused by the lateral soil arch effect, so as to simulate the influence of the soil arch effect in the vertical direction of the soil on the shield tunnel during the construction of the shield tunnel.

[0053] Step 2: Fill the space for bearing the soil formed by the box body 5 and the tunnel model 1 with soil, and let it stand still after the soil filling is completed.

[0054] Among them, when filling the soil, one type of parameter soil can be filled, or different types and parameters of soil can be filled in layers to simulate the change of the arch axis under different soil conditions. When filling different types and parameters of soil in layers, each layer of filled soil needs to be compacted. After each layer is filled, level the filled layer, and then let it stand still for no less than 1 hour. In this way, the soil filling can be made more compact and closer to the actual working conditions, which is beneficial to the generation of the "arch effect" of the soil. After standing still for a period of time, fill the next layer, and so on until all the soil is filled. After all the soil is filled, let it stand still for 24 to 36 hours. After completion, the model of the shield tunnel before excavation is established.

[0055] Step 3: Turn on the three-dimensional scanner 7, and slowly separate the tunnel model 1 from the box body 5 until the tunnel model 1 is completely separated from the box body 5.

[0056] Among them, during the process of slowly separating the tunnel model 1 from the box body 5, some soil will collapse. At this time, it is necessary to closely pay attention to the state of the soil in the box body 5. If the soil is unstable, stop the movement of the tunnel model 1 until the soil is stable and then move the tunnel model 1 again. The basis for judging the soil instability is that the continuous falling time of the soil in the box body 5 exceeds 30 seconds, and there is no tendency for the falling speed to slow down within 10 seconds.

[0057] Step 4: Output the measurement results of the 3D scanner 7 as CAD drawings to obtain the arch axes of the spatial soil arch effect in different test stages.

[0058] Among them, the 3D scanner 7 is preferably a laser 3D scanner to achieve non-contact measurement. After the measurement is completed, connect the 3D scanner 7 to a computer, read the measurement data of the 3D scanner 7 and import it into CAD, and the arch axes of the spatial soil arch effect in different test stages can be obtained.

[0059] In summary, the advantages and beneficial effects of the present invention are as follows:

[0060] The present invention can accurately and automatically measure the arch axes of the soil arch effect in the spatial state, solve the technical problem that it is difficult to accurately measure the arch axes of the spatial soil arch effect in existing tests, and thus can better reflect the internal law of the soil arch effect and master the influence of the soil arch effect on the construction of shield tunnels.

[0061] At the same time, the present invention uses a laser 3D scanner 7 to measure the arch axis, which is simple to operate and has high measurement accuracy; the box body 5 is made of transparent organic glass material (acrylic material), which is convenient for test operation and intuitive observation of the soil arch effect; the tunnel model 1 is made of smooth acrylic material, which can reduce the resistance brought by the soil; multiple rollers 4 are used to support the tunnel model 1, and a rubber layer is provided on the circumferential surface of the rollers 4, which can ensure the smooth detachment of the tunnel model 1 and make the test closer to the real state; when establishing the model, the axis of the tunnel model 1 and the upper surface of the bottom plate are placed in the same plane, which can reduce the influence of the lateral soil arch effect; when filling the soil, different types and parameters of soil can be filled in layers to simulate the change of the arch axis under different soil conditions; during the test, the tunnel model 1 is slowly pulled out of the box body 5 through the pulling device, which can make the tunnel model 1 slide smoothly without causing great disturbance to the soil.

[0062] As is known by technical common sense, the present invention can be implemented by other embodiments without departing from its spiritual essence or essential features. Therefore, the above-disclosed embodiments are illustrative in all respects and are not exclusive. All changes within the scope of the present invention or equivalent to the present invention are encompassed by the present invention.

Claims

1. A measurement system for the spatial soil arch induced by the excavation of a model tunnel, characterized in that, Comprising: A box body, a tunnel model, a supporting device and a three-dimensional scanner; A rectangular slot is provided at the bottom of the box body; The tunnel model is blocked at the rectangular slot, and the bottom abuts against the supporting device. The tunnel model and the box body form a space for carrying soil; When moving the tunnel model, the soil collapses from the rectangular slot; The supporting device abuts against the tunnel model below the tunnel model for supporting the tunnel model; The three-dimensional scanner is located below the box body for measuring the arch axis formed after simulating the construction of a shield tunnel; The supporting device includes a base and rollers; The rollers are installed on the base, and the rollers are rotatably connected to the base; Further comprising: a pulling device connected to the tunnel model for pulling the tunnel model; The pulling device includes a coupling shaft, a connecting rod, a pull rod and a lever; the coupling shaft is located inside the tunnel model and is fixedly connected to the tunnel model; the connecting rod is located inside the tunnel model, and one end is fixedly connected to the coupling shaft; the pull rod is located outside the tunnel model, one end of the pull rod is connected to the other end of the connecting rod, and the other end of the pull rod is connected to the lever.

2. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 1, wherein: There are multiple rollers, which are evenly distributed along the length direction of the rectangular slot, and the axis of the rollers is perpendicular to the length direction of the rectangular slot.

3. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 1, wherein A rubber layer is provided on the circumferential surface of the rollers.

4. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 1, wherein The pulling device is any one of a hydraulic cylinder, a pneumatic cylinder, a linear motor, a lead screw transmission device, a rope and a handle.

5. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 1, wherein: The box body includes a front plate, a left plate, a rear plate, a right plate connected in sequence, and a bottom plate respectively connected to the front plate, the left plate, the rear plate and the right plate. The rectangular slot is located in the middle of the bottom plate.

6. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 5, characterized in that, The material of the box body is transparent organic glass.

7. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 5, characterized in that, The bottom plate includes a first bottom plate and a second bottom plate, and the first bottom plate and / or the second bottom plate are slidably arranged below the front plate, the left plate, the rear plate and the right plate.

8. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 5, wherein: The axis of the tunnel model and the upper surface of the bottom plate are in the same plane.

9. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 8, characterized in that, The material of the tunnel model is smooth acrylic material.

10. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 1, wherein: The lens of the three-dimensional scanner is directly below the symmetric center of the rectangular slot.

11. The measurement system for the spatial soil arch caused by the excavation of the model tunnel according to claim 10, characterized in that, The three-dimensional scanner is a laser three-dimensional scanner.

12. A measurement method for the spatial soil arch induced by model tunnel excavation, the measurement method for the spatial soil arch induced by model tunnel excavation is realized based on the measurement system for the spatial soil arch induced by model tunnel excavation according to any one of claims 1 to 11, characterized in that, Comprising: Step 1: Place the tunnel model at the rectangular slot, and use the supporting device to support the tunnel model at the bottom of the tunnel model so that the tunnel model completely blocks the rectangular slot; Step 2: Fill the space for carrying soil formed by the box body and the tunnel model with soil, and let it stand after the soil filling is completed; Step 3: Turn on the 3D scanner, and slowly separate the tunnel model from the box until the tunnel model is completely separated from the box; Step 4: Output the measurement results of the 3D scanner as a CAD drawing to obtain the arch axis of the spatial soil arch effect at different test stages.

13. The method for measuring the spatial soil arch caused by the excavation of the model tunnel according to claim 12, wherein: In step 1, when placing the tunnel model, make the axis of the tunnel model and the upper surface of the bottom plate of the box be in the same plane.

14. The method for measuring the spatial soil arch caused by the excavation of the model tunnel according to claim 12, wherein: In step 2, fill the soil with different types and parameters in layers. After each layer is filled, level it, let it stand for not less than 1 hour and then fill the next layer. After all the soil is filled, let it stand for 24 to 36 hours.

15. The method for measuring the spatial soil arch caused by the excavation of the model tunnel according to claim 12, wherein: In step 3, when the tunnel model is slowly separated from the box, if the soil is unstable, stop the movement of the tunnel model until the soil is stable and then move the tunnel model again.

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