Underground cavern physical model test device and method
By using a telescopic strut and baffle structure, combined with a pull rod and support locking mechanism, the problem that existing technologies cannot truly reflect the impact of drill-and-blast excavation is solved. This enables flexible simulation of the stress characteristics and failure patterns of underground caverns, and is applicable to the simulation of caverns of various shapes and sizes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-13
- Publication Date
- 2026-04-03
AI Technical Summary
Existing physical model testing methods for underground cavern excavation cannot accurately reflect the stress conditions of actual engineering projects, especially the impact of drill-and-blast excavation on the surrounding rock.
The device employs a retractable strut and baffle structure to simulate the deformation capacity of the strata, and uses pull rods to simulate drill-and-blast excavation. Combined with supports and expansion components to lock the baffle position, the device can be disassembled and flexibly adjusted to simulate the mechanical behavior of isotropic or anisotropic strata.
It effectively reflects the impact of excavation and unloading on the deformation characteristics and failure patterns of the surrounding rock, realistically simulates the drill-and-blast excavation process, is easy to operate, and can simulate underground caverns of different shapes and sizes.
Smart Images
Figure CN121783687A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of underground engineering material model testing technology, and in particular to a physical model testing device and method for underground caverns. Background Technology
[0002] Underground caverns are located in complex geological environments. To ensure the safety of underground cavern construction, physical model testing is widely used as an effective testing method to study the stress characteristics and failure patterns of the surrounding rock during the excavation of underground caverns.
[0003] Currently, there are two main methods for physical model testing of underground cavern excavation: one is to place a hollow mold at the location of the cavern to be tested, then pour concrete on the outside of the hollow mold to form a stratum model, and then apply pressure around the stratum model to simulate in-situ stress, thereby studying the deformation and stress characteristics of the surrounding rock of the cavern. This method of directly pouring concrete on the hollow mold to form a hollow stratum model (i.e., the cavern is there first, then pressure is applied) cannot truly reflect the stress situation of the actual project.
[0004] Another method involves casting a solid geological model, applying pressure around the model, and then hollowing out the interior using drill bits and chisels. The deformation and stress characteristics of the surrounding rock after hollowing out are then studied. However, this method, which uses drill bits or chisels, cannot effectively simulate the actual excavation process of the tunnel drilling and blasting method and cannot effectively reflect the impact of excavation unloading on the surrounding rock. Summary of the Invention
[0005] The purpose of this invention is to provide a physical model test device and method for underground caverns, which can effectively simulate the stress characteristics and failure patterns of the surrounding rock in underground caverns excavated by the drill-and-blast method.
[0006] The technical solution of the present invention is: a physical model test device for underground caverns, comprising a support frame, a rotating shaft rotatably disposed within the support frame, and multiple support rods telescopically installed on the support frame. The rotating shaft rotates to drive the multiple support rods to extend and retract radially. A baffle is connected to one end of each support rod away from the rotating shaft, and the baffle surrounds the outer periphery of the support frame. One end of the rotating shaft is provided with a first shaft hole for detachably installing a pull rod, and the other end of the rotating shaft is provided with a second shaft hole, in which a support is provided. An expansion member is detachably installed in the support, which can expand the support to limit the relative position between the rotating shaft and the support frame. The support rods are distributed on the outer periphery of the support frame. The support rod on one side of the support frame has a cross-section A, and the support rod on the opposite side of the support frame has a cross-section B. A=B to simulate isotropic geological mechanical behavior of the cavern, and A≠B to simulate anisotropic geological mechanical behavior of the cavern.
[0007] In the above scheme, retractable struts and baffles are installed, which can be adjusted according to the deformation capacity of the simulated strata. It can simultaneously simulate the mechanical behavior of isotropic or anisotropic strata. The device is then pulled out using a pull rod to realistically simulate the drill-and-blast method for excavating underground caverns, effectively reflecting the impact of excavation unloading on the deformation characteristics and failure patterns of the surrounding rock. Different cross-sectional areas of the struts on opposite sides of the support frame (such as left and right sides or front and back sides) can simulate anisotropic mechanical behavior; if all struts have the same cross-sectional area, isotropic mechanical behavior is simulated.
[0008] Preferably, the support frame includes side plates that enclose to form a square column and a flat plate covering each end of the side plates. The side plates are provided with telescopic holes for the extension and retraction of the support rods. The baffle is slidably disposed between the two flat plates, and the rotating shaft is rotatably connected to the flat plate.
[0009] Preferably, each of the two flat plates has a groove on one of its opposite surfaces, and a slider adapted to the groove is connected to the baffle plate.
[0010] Preferably, one of the flat plates is provided with an insertion hole corresponding to the first shaft hole, and the other flat plate is provided with a first threaded hole corresponding to the second shaft hole; one end of the support is connected to the first threaded hole, and the other end of the support extends into the second shaft hole.
[0011] Preferably, the support includes a bushing with an inner hole and a plurality of petals circumferentially connected to one side of the bushing. One end of the bushing with the petals extends into a second shaft hole, and the end of the bushing away from the petals is connected to a support frame. The expansion member is installed in the inner hole of the bushing and can expand the petals to abut against the inner wall of the second shaft hole.
[0012] Preferably, the expansion member includes a first handle, a round rod, and a conical head connected in sequence. The round rod is placed in the inner hole of the bushing and connected to the support. The conical head is adapted to multiple valves. The first handle is detachably connected to the round rod.
[0013] Preferably, the pull rod includes a second handle and a rod body connected to the second handle, the rod body being adapted to the first shaft hole.
[0014] Preferably, the first shaft hole is a square hole, and the pull rod is provided with a square head that is adapted to the first shaft hole.
[0015] Preferably, the rotating shaft includes a shaft body rotatably connected to the support frame and a plurality of paddles circumferentially connected to the shaft body. The side of each paddle away from the shaft body is an arc-shaped surface, which is adapted to the support rod.
[0016] The present invention also provides a method for testing a physical model of an underground cavern, comprising the following steps: Step 1: Place the above-mentioned underground cavern physical model test device horizontally; Step 2: Drive the rotating shaft to rotate to extend the baffle, and install the expansion component to lock the position of the baffle; Step 3: Pour concrete outside the test apparatus to form a ground model; apply pressure to the ground model to simulate ground stress; Step 4: Insert the pull rod to pull out the test device, which will create a hole in the formation model. Step 5: Examine the deformation and cracking of the inner wall of the hole, and output its deformation and stress characteristics.
[0017] Compared with related technologies, the beneficial effects of the present invention are as follows: I. The present invention is equipped with retractable struts and baffles, which can be adjusted according to the deformation capacity of the simulated strata, and can simultaneously simulate the mechanical behavior of isotropic or anisotropic strata. The device is then pulled out by a pull rod to realistically simulate the drilling and blasting method for excavating underground caverns, effectively reflecting the influence of excavation unloading on the deformation characteristics and failure law of the surrounding rock. Second, this invention simulates the excavation and unloading effect of drilling and blasting on the surrounding rock in different strata (isotropic or anisotropic strata); it can realistically simulate the actual excavation process of caverns; it is relatively flexible and can excavate underground caverns of various shapes, sizes and dimensions. Third, the present invention uses a support and expansion component structure to lock the position of the baffle, which is a mechanical locking method that is convenient to operate, effectively locks, and is easy to unlock. Attached Figure Description
[0018] Figure 1 A three-dimensional structural schematic diagram of the pull-out rod in the underground cavern physical model test device provided by the present invention, from the first perspective. Figure 2 A three-dimensional structural diagram of the pull-out rod in the underground cavern physical model test device provided by the present invention, from a second perspective. Figure 3 A structural diagram of the supporting frame; Figure 4 This is a schematic diagram of the connection structure between the baffle and the slider; Figure 5 This is a schematic diagram of the rotating shaft. Figure 6 for Figure 5 Perspective view; Figure 7 This is a structural schematic diagram of the support; Figure 8 This is a schematic diagram of the expansion component; Figure 9 This is a schematic diagram showing the installation of the expansion joint and the support. Figure 10 This is a schematic diagram of the pull rod structure; Figure 11 This is a schematic diagram of the combination of underground caverns.
[0019] In the attached diagram: 1. Support frame; 11. Side plate; 111. Telescopic hole; 12. Flat plate; 121. Slide groove; 122. Insertion hole; 123. First threaded hole; 2. Baffle; 3. Rotating shaft; 31. Shaft body; 32. Paddle; 321. Arc surface; 33. First shaft hole; 34. Second shaft hole; 4. Support; 41. Bushing; 42. Petal body; 43. Second threaded hole; 44. Conical hole; 5. Expansion member; 51. First handle; 52. Round rod; 53. Conical head; 6. Pull rod; 61. Second handle; 62. Rod body; 63. Square head; 7. Support rod; 8. Slider; 10. Rigidity block. Detailed Implementation
[0020] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. For ease of description, the terms "upper," "lower," "left," and "right" used below only indicate that they correspond to the upper, lower, left, and right directions in the accompanying drawings and do not limit the structure.
[0021] like Figure 1 , Figure 2 As shown, the physical model test device for underground cavern provided in this embodiment includes a support frame 1, a baffle 2, a rotating shaft 3, a support 4, an expansion member 5, a pull rod 6, a strut 7, and a slider 8.
[0022] like Figure 3 As shown, the support frame 1 includes side plates 11 that enclose a square column on all four sides, and flat plates 12 connected to both ends of the side plates 11. The flat plates 12 extend to the outside of the square column enclosed by the side plates 11. A cross-shaped groove 121 is provided on one side of the two side plates 11 that are close to each other. A baffle 2 is slidably disposed between the two flat plates 12. A baffle 2 is provided on each side of the square column. Figure 4 As shown, sliders 8 are connected to the upper and lower ends of the baffle 2. Figure 2 As shown, the slider 8 is slidably connected in the groove 121.
[0023] like Figure 3 As shown, the side plate 11 is provided with telescopic holes 111 for the extension and retraction of the support rods 7. Multiple support rods 7 are arranged along the height direction of the side plate 11 (the axial direction of the rotation shaft 3). Figure 2 As shown, the rotating shaft 3 is rotatably connected to the plate 12. Figure 2 , Figure 5 , Figure 6As shown, one end of the rotating shaft 3 is provided with a first shaft hole 33 for detachably installing the pull rod 6, and the other end of the rotating shaft 3 is provided with a second shaft hole 34. The first shaft hole 33 is a square hole. The rotating shaft 3 includes a shaft body 31 and a plurality of paddles 32 circumferentially connected to the shaft body 31. Both ends of the shaft body 31 may be provided with bosses, each boss having an inner hole communicating with the first shaft hole 33 and the second shaft hole 34, and the bosses must allow space for the insertion hole 122 and the threaded hole 123. The side of the paddle 32 away from the shaft body 31 is an arc-shaped surface 321, which is adapted to the support rod 7. Rotating the shaft body 31 causes the paddles 32 to rotate together, pushing the support rod 7 radially outward through the arc-shaped surface 321. The number of paddles 32 corresponds one-to-one with the number of support rods 7.
[0024] like Figure 2 As shown, the flat plate 12 is provided with an insertion hole 122 corresponding to the first shaft hole 33, such as Figure 1 As shown, another plate 12 is provided with a first threaded hole 123 corresponding to the second shaft hole 34. The insertion hole 122 may be a square hole with the same shape as the first shaft hole 33 or a round hole with a diameter larger than the first shaft hole 33.
[0025] like Figure 2 As shown, a support 4 is provided in the second shaft hole 34. An expansion member 5 is detachably installed in the support 4, which can expand the support 4 to limit the relative position between the rotating shaft 3 and the support frame 1.
[0026] like Figure 7 As shown, the support 4 includes a bushing 41 with an inner hole and a plurality of flaps 42 circumferentially connected to one side of the bushing 41. The inner hole of the bushing 41 is a second threaded hole 43. The plurality of flaps 42 surround and form a conical hole 44.
[0027] like Figure 2 As shown, the valve body 42 extends into the second shaft hole 34, and the outer surface of the bushing 41 away from the valve body 42 is provided with an external thread, which is threadedly connected to the first threaded hole 123.
[0028] like Figure 8 As shown, the expansion member 5 includes a first handle 51, a round rod 52, and a conical head 53 connected in sequence. Figure 9 As shown, the round rod 52 has external threads on its exterior. The round rod 52 is placed in the inner hole of the bushing 41, and the external threads are connected to the second threaded hole 43. The conical head 53 is inserted into the conical hole 44, causing the flap 42 to open and abut against the inner wall of the second shaft hole 34 (e.g., Figure 2As shown, the expansion member 5 is placed in the inner hole of the bushing 41 and connected to the support 4. The conical head 53 is adapted to multiple petals 42 to lock the relative position of the rotating shaft 3 and the support frame 1, thereby locking the position of the baffle 2. The first handle 51 and the round rod 52 are detachably connected (e.g., detachably connected by means of inserts, slots, or by means of threaded connection).
[0029] like Figure 10 As shown, the pull rod 6 includes a second handle 61 and a rod body 62 connected to the second handle 61. The end of the rod body 62 is provided with a square head 63 that is adapted to the first shaft hole 33.
[0030] The present invention also provides a method for testing a physical model of an underground cavern, comprising the following steps: Step 1: Place the above-mentioned underground cavern physical model test device horizontally; Step two: Insert the pull rod 6 into the first shaft hole 33, drive the rotating shaft 3 to rotate to extend the baffle 2, and install the expansion member 5 to lock the position of the baffle 2. Then, pull out the pull rod 6 and the first handle 51 respectively. Step 3: Pour concrete outside the test apparatus to form a ground model; apply pressure to the ground model to simulate ground stress; Step four: Insert the pull rod 6 to pull out the test device, which will create a hole in the formation model. To facilitate the removal of the test device, before pouring in step three, cover the outer surface of the baffle 2 and the plate 12 with a layer of oil-impregnated paper or plastic film. Step 5: Examine the deformation and cracking of the inner wall of the hole, and output its deformation and stress characteristics.
[0031] like Figure 11 As shown, multiple test devices can be fabricated according to the combined structure of the underground cavern, with each test device forming a rigid block 10. Each test device can be designed with a different shape to simulate different excavation parts of the underground cavern, such as arches and sidewalls.
[0032] The stiffness of the strut 7 is set based on the simulated geological formation, and the isotropic or anisotropic behavior of the stiffness block is determined. The extension length of the strut 7 is adjusted by rotating the rotation axis 3 to simulate the required stiffness, achieving different stiffness adjustment controls. Multiple stiffness adjustments can be achieved for the same experimental device by increasing the number of struts 7. For example, if the struts 7 in the X and Y directions are the same size, it is isotropic; otherwise, it is anisotropic. In step four, the stiffness of the struts 7 can be adjusted separately... Figure 11 Each experimental device was pulled out to simulate the layered excavation of underground caverns, thereby simulating the stress characteristics and failure patterns of the surrounding rock of caverns under the layered excavation method of drill and blast.
[0033] This invention uses a pull rod to quickly pull out the test device layer by layer and part by part, which can simulate the layered excavation process of underground cavern using the drilling and blasting method, and can reflect the influence of excavation unloading on the deformation characteristics and failure law of the surrounding rock.
[0034] This invention involves casting a variable stiffness block (experimental device) simulating an underground cavern into a geological model, and then rapidly pulling out the variable stiffness block of the simulated underground cavern layer by layer using pull rods, thereby simulating the stress characteristics and failure law of the surrounding rock of the cavern under the layered excavation method of drill and blast.
[0035] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.
Claims
1. A physical model test device for underground caverns, characterized in that, The device includes a support frame (1), a rotating shaft (3) rotatably disposed within the support frame (1), and multiple support rods (7) telescopically mounted on the support frame (1). The rotating shaft (3) rotates to drive the multiple support rods (7) to extend and retract radially. A baffle (2) is connected to one end of each support rod (7) away from the rotating shaft (3), and the baffle (2) surrounds the outer periphery of the support frame (1). One end of the rotating shaft (3) is provided with a first shaft hole (33) for detachably installing a pull rod (6), and the other end of the rotating shaft (3) is provided with a second shaft hole (34). The second shaft hole (34) is provided with a support (4); an expansion member (5) is detachably installed in the support (4). The expansion member (5) can open the support (4) to limit the relative position between the rotating shaft (3) and the support frame (1). The struts (7) are respectively arranged on the outer periphery of the support frame (1). The strut (7) arranged on one side of the support frame (1) has a cross section A, and the strut (7) arranged on the other side of the support frame (1) has a cross section B. A=B is used to simulate the isotropic geological mechanical behavior of the cavern, and A≠B is used to simulate the anisotropic geological mechanical behavior of the cavern.
2. The underground cavern physical model test device according to claim 1, characterized in that, The support frame (1) includes a side plate (11) that encloses to form a square column and a flat plate (12) covering each end of the side plate (11). The side plate (11) is provided with a telescopic hole (111) for the extension and retraction of the support rod (7). The baffle (2) is slidably disposed between the two flat plates (12). The rotating shaft (3) is rotatably connected to the flat plate (12).
3. The underground cavern physical model test device according to claim 2, characterized in that, Each of the two flat plates (12) has a groove (121) on one side surface facing each other, and a slider (8) adapted to the groove (121) is connected to the baffle (2).
4. The underground cavern physical model test device according to claim 2, characterized in that, One of the flat plates (12) is provided with an insertion hole (122) corresponding to the first shaft hole (33), and the other flat plate (12) is provided with a first threaded hole (123) corresponding to the second shaft hole (34); one end of the support (4) is connected to the first threaded hole (123), and the other end of the support (4) extends into the second shaft hole (34).
5. The physical model test device for underground caverns according to claim 1, characterized in that, The support (4) includes a bushing (41) with an inner hole and a plurality of valves (42) circumferentially connected to one side of the bushing (41). One end of the bushing (41) with the valves (42) extends into the second shaft hole (34). The end of the bushing (41) away from the valves (42) is connected to the support frame (1). The expansion member (5) is installed in the inner hole of the bushing (41) and can expand the valves (42) to abut against the inner wall of the second shaft hole (34).
6. The underground cavern physical model test device according to claim 5, characterized in that, The expansion member (5) includes a first handle (51), a round rod (52) and a conical head (53) connected in sequence. The round rod (52) is placed in the inner hole of the bushing (41) and connected to the support (4). The conical head (53) is adapted to multiple valves (42). The first handle (51) is detachably connected to the round rod (52).
7. The physical model test device for underground caverns according to claim 1, characterized in that, The pull rod (6) includes a second handle (61) and a rod body (62) connected to the second handle (61), the rod body (62) being adapted to the first shaft hole (33).
8. The physical model test device for underground caverns according to claim 1, characterized in that, The first shaft hole (33) is a square hole, and the pull rod (6) is provided with a square head (63) that is adapted to the first shaft hole (33).
9. The physical model test device for underground caverns according to claim 1, characterized in that, The rotating shaft (3) includes a shaft body (31) rotatably connected to the support frame (1) and a plurality of paddles (32) circumferentially connected to the shaft body (31). The side of the paddle (32) away from the shaft body (31) is an arc surface (321), and the arc surface (321) is adapted to the support rod (7).
10. A method for testing physical models of underground caverns, characterized in that, Includes the following steps: Step 1: Place the underground cavern physical model test device as described in any one of claims 1-9 horizontally; Step 2: Drive the rotating shaft (3) to rotate to extend the baffle (2), and install the expansion member (5) to lock the position of the baffle (2); Step 3: Pour concrete outside the test apparatus to form a ground model; apply pressure to the ground model to simulate ground stress; Step 4: Insert the pull rod (6) to pull out the test device. Pulling out the test device will create a hole in the formation model. Step 5: Examine the deformation and cracking of the inner wall of the hole, and output its deformation and stress characteristics.