Multi-functional test system and method for karst areas with fault fracture zones under heavy rainfall

Abstract

The present invention discloses a multifunctional test system and method for a karst area with a fault fracture zone under heavy rainfall, which relates to the technical field of tunnel construction and includes: a model box, with a plurality of rainfall holes penetrating through the upper and lower surfaces at the top; a folding skeleton, arranged inside the model box, and a single-inclination or multi-inclination simulated fault is defined between two adjacent folding skeletons; a tunnel model, arranged inside the model box and penetrating through the folding skeleton, and one end of the tunnel model extends outside the model box; a water supply mechanism, communicated with the rainfall holes through a conveying pipeline, and a water supply pump is arranged on the conveying pipeline. The folding skeleton is used to simulate the fault structure with single inclination or multi-inclination, the terrain simulation is more realistic, and the test accuracy is improved. The model combines a fault fracture zone and an underground river, and can monitor the mechanism of water inrush and mud inrush jointly induced by the fault fracture zone and the underground river under heavy rainfall conditions, so as to guide the current project construction or provide reference for future similar project construction.

Description

Technical Field

[0001] The present invention relates to the technical field of tunnel construction, and particularly to a multi-functional test system and method for a karst area with a fault fracture zone under heavy rainfall. Background Art

[0002] Tunnel construction inevitably needs to cross terrains. Among various terrains, a fault fracture zone is a section where rocks are strongly fractured due to faults or fracture concentration zones. During tunnel construction, especially during rainy season construction, the fault fracture zone is prone to causing accidents such as water inrush and mud inrush, thus resulting in economic losses and extended construction periods.

[0003] Therefore, it is necessary to conduct simulation research on the water inrush and mud inrush mechanisms of the fault fracture zone under heavy rainfall conditions, so as to guide current engineering construction or provide reference for future similar engineering construction.

[0004] The existing technologies can construct a fault fracture zone model and observe the lining situation under heavy rainfall conditions, but there are the following deficiencies:

[0005] 1. The fault fracture zone is divided into single dip angle and multi-dip angle. The existing technologies can only construct a single-dip-angle fault fracture zone and cannot simulate multi-dip angles, so the terrain simulation authenticity is insufficient.

[0006] 2. When there is a composite fault fracture zone and an underground river in the terrain, they will jointly induce water inrush and mud inrush under heavy rainfall conditions. The existing technologies cannot construct a composite model of the fault fracture zone and the underground river.

[0007] In view of this, how to provide a karst tunnel test model and test method that can simulate a multi-dip-angle fault fracture zone and a composite underground river is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0008] The purpose of the present invention is to provide a multi-functional test system and method for a karst area with a fault fracture zone under heavy rainfall to solve the problems existing in the prior art.

[0009] To achieve the above purpose, the present invention provides a multi-functional test system for a karst area with a fault fracture zone under heavy rainfall, including:

[0010] A model box, which is hollow inside and has a plurality of rainwater holes penetrating through the upper and lower surfaces at the top;

[0011] A folding skeleton, which is arranged inside the model box. A single-dip-angle or multi-dip-angle simulated fault is defined between two adjacent folding skeletons; the simulated fault is filled with broken rock and soil mass, and the cavity between the folding skeleton and the inner side wall of the model box is filled with rock and soil mass;

[0012] A tunnel model is arranged inside the model box and penetrates through the folding framework, and one end of the tunnel model extends outside the model box.

[0013] A water supply mechanism is communicated with the rainwater drainage holes through a conveying pipeline, and a water supply pump is arranged on the conveying pipeline.

[0014] Furthermore, it further includes:

[0015] A sliding pull rod is arranged inside the simulated fault, and two ends of the sliding pull rod are respectively connected to two adjacent folding frameworks.

[0016] Furthermore, the folding framework includes:

[0017] A plurality of folding frames, adjacent folding frames are hinged through hinge members, and after the plurality of folding frames rotate, a single inclination angle or multiple inclination angles are formed.

[0018] A locking member, when the plurality of folding frames rotate to form a single inclination angle or multiple inclination angles, the locking member is used to lock the hinge member.

[0019] Furthermore, the hinge member is a pin shaft, and the locking member is a wedge-shaped locking device.

[0020] Furthermore, the folding frame is of a hollow structure, a filter screen is arranged on its inner frame body, and a simulated fault is defined between the filter screens of two adjacent folding frameworks.

[0021] Furthermore, it further includes:

[0022] A prefabricated member, which is an arc-shaped plate structure with an upper opening, the prefabricated member is arranged inside the model box and penetrates through the folding framework, and two ends of the prefabricated member extend outside the model box.

[0023] A circulation pump, two ends of the prefabricated member are respectively communicated with the water supply mechanism through a water inlet pipeline and a water outlet pipeline, the circulation pump is arranged on the water inlet pipeline, and the circulation pump supplies water into the prefabricated member to form a simulated underground river.

[0024] Furthermore, it further includes a controller, the controller is electrically connected to the water supply pump and the circulation pump, and the controller is used to control the output power of the water supply pump and the circulation pump.

[0025] Furthermore, a support net is arranged at the upper opening of the prefabricated member, and the support net is used to support the rock and soil body above the prefabricated member.

[0026] Furthermore, it further includes:

[0027] A digital camera is arranged outside the model box and corresponds to one end of the tunnel model.

[0028] The present invention also provides a multifunctional test method for a fault-fragmented zone in a karst area under heavy rainfall, and the multifunctional test system for a fault-fragmented zone in a karst area under heavy rainfall is applied, comprising the following steps:

[0029] S1: Arrange the tunnel model at the bottom of the model box, rotate multiple folding frames to form a folding frame with a single or multiple inclination angles, and lock the hinges with locking pieces;

[0030] S2: Reserve installation holes for the tunnel model and prefabricated components on the filter screen of the foldable frame, place two foldable frames in the model box, and adjust the distance between the two foldable frames by a sliding pull rod until the preset width is reached to form a simulated fault;

[0031] S3: Fill the simulated fault with broken rock and soil from bottom to top, and fill the cavity between the foldable frame and the inner wall of the model box with rock and soil. When the broken rock and soil and the rock and soil are filled to the setting height of the prefabricated component, install the prefabricated component; continue to fill the broken rock and soil and the rock and soil until the top of the model box is reached;

[0032] S4: The controller starts the water supply pump and the circulation pump, and the water supply pump and the circulation pump supply water to the rainwater hole and the prefabricated component respectively according to the preset power;

[0033] S5: Acquire the lining image of the tunnel model by a digital camera.

[0034] The present invention discloses the following technical effects:

[0035] 1. The folding skeleton is used to simulate the fault structure with single or multiple dip angles, making the terrain simulation more realistic and improving the test accuracy.

[0036] 2. The foldable skeleton is formed by hingedly connecting multiple foldable frames. According to different test requirements, the number of dip angles, dip angles and width between adjacent dip angles of the simulated fault can be flexibly adjusted. The overall bandwidth can also be adjusted by a sliding pull rod to make the simulated fault close to the real fault morphology, further improving the test accuracy.

[0037] 3. The model provided by the present invention combines fault fracture zones and underground rivers, and can monitor the mechanism by which fault fracture zones and underground rivers jointly induce water and mud gushing under heavy rainfall conditions, thereby guiding current engineering construction or providing reference or reference for future similar engineering construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 Structural schematic diagram of the present invention;

[0040] Figure 2 Layout diagram of a digital camera;

[0041] Figure 3 Structural schematic diagram of a sliding pull rod;

[0042] Figure 4 Schematic diagram of a single-inclination folding framework;

[0043] Figure 5 Schematic diagram of a double-inclination folding framework;

[0044] Figure 6 Schematic diagram of a triple-inclination folding framework;

[0045] Figure 7 Schematic diagram of a special-shaped folding framework;

[0046] Among them, 1, model box; 2, rainwater drainage hole; 3, folding framework; 301, folding frame; 302, hinge; 4, tunnel model; 5, water supply mechanism; 6, sliding pull rod; 7, prefabricated component; 8, digital camera. Detailed implementation manners

[0047] In the retrieved prior art:

[0048] Patent 202210814157.2 discloses an experimental device for simulating faults, including a core sample box body and a cover plate. The core sample box body is a cuboid with an open top surrounded by four side plates on the left, right, front, and rear and a bottom plate, which can not only simulate the real environment of faults but also conduct research on various working conditions such as the influence of fault dip changes on oil and water wells.

[0049] Patent 201910049175.4 discloses a three-dimensional similarity physical test device for simulating fault dislocation, which can accurately simulate the fault occurrence (strike, dip, and inclination), and at the same time, on the premise of avoiding the "three-dimensional box effect" and ensuring the simulated initial stress field, quantify the process of fault activation, realize the observation of the lining cracking process and failure mode, ensure the accuracy and rationality of the test, and improve the standardization and operability of the test.

[0050] Patent 201610332788.5 discloses a device and method for simulating water and mud inrush during fault movement. This device can measure the flow rate of mud under different water pressures, and based on the flow rate, it can determine under what water pressure the water and mud inrush phenomenon will occur.

[0051] Patent 202011385075.8 discloses a test device and determination method for simulating a pipeline crossing a strike-slip fault. This device can be used to study the stress conditions of pipelines crossing faults with different displacements and the interaction between the pipeline and the soil. While reducing the test cost, it can truly and accurately simulate the failure mechanism of pipelines under strike-slip faults.

[0052] Patent 202011318812.2 discloses a device and method for simulating the dynamic response of a tunnel under fault dislocation. This device realizes the simulation of the dynamic response of tunnels under the dislocation of different types and different dip angles of faults, which is beneficial to the research on the failure mechanism and anti-fault design of tunnels crossing faults.

[0053] Patent 202010017450.7 discloses a test device for simulating a tunnel crossing an active fault. This device can not only simulate the surrounding rock at the bottom of an urban shallow-buried subway tunnel but also simulate the subway tunnel under different dislocation rates. In addition, this experimental device can simulate the stress conditions of a tunnel crossing an active fault with different burial depths, different properties of the surrounding rock at the bottom of the tunnel, and different angles between the fault and the tunnel.

[0054] Patent 202110089844.8 discloses a test device and method for simulating the instability mechanism of a tunnel under fault slip and dislocation. This test device can truly simulate the three-dimensional static and dynamic loads and the multi-fault two-way slip composite environment in which the tunnel is located in actual working conditions.

[0055] The fault simulations in the above patents are all single-dip angle faults, which cannot simulate multi-dip angle faults and cannot construct a composite model of a fault fracture zone and an underground river.

[0056] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0057] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

[0058] The embodiments of the present invention provide a multifunctional test system for a karst area with a fault fracture zone under heavy rainfall, including:

[0059] Model box 1, the model box 1 is of a cuboid structure, and all four sides are made of tempered glass. The joints are sealed by a sealing rubber and a leak-proof glue. The top of the model box 1 can be opened and closed for filling rock and soil bodies, crushing rock and soil bodies, and installing internal structures. The inside of the model box 1 is hollow, and a plurality of rainwater holes 2 are opened through the upper and lower surfaces at the top;

[0060] Folding skeleton 3, arranged inside the model box 1. A single-inclination or multi-inclination simulated fault is defined between two adjacent folding skeletons 3; the simulated fault is filled with crushed rock and soil bodies, and the cavity between the folding skeleton 3 and the inner side wall of the model box 1 is filled with rock and soil bodies;

[0061] Tunnel model 4, arranged inside the model box 1 and passing through the folding skeleton 3, and one end of the tunnel model 4 extends outside the model box 1;

[0062] Water supply mechanism 5, connected to the rainwater holes 2 through a conveying pipeline, and a water supply pump is arranged on the conveying pipeline.

[0063] In this embodiment, it further includes:

[0064] Sliding pull rod 6, arranged inside the simulated fault, and both ends of the sliding pull rod 6 are respectively connected to two adjacent folding skeletons 3. The sliding pull rod 6 is of a telescopic rod structure (non-elastic telescopic rod). The main function of the sliding pull rod 6 is to facilitate the adjustment of the distance between two adjacent folding skeletons 3, and the distance between the two ends of the folding skeleton 3 can be adjusted to be the same or different, so as to simulate faults of different forms.

[0065] In this embodiment, the folding skeleton 3 includes:

[0066] A plurality of folding frames 301, and the adjacent folding frames 301 in the vertical direction are hinged by hinge members 302. After the plurality of folding frames 301 rotate, a single-inclination or multi-inclination is formed; to improve the structural stability, a plurality of hinge members 302 can be arranged between the adjacent folding frames 301 in the vertical direction, and the plurality of hinge members 302 are located on the same horizontal line.

[0067] Locking member, when the plurality of folding frames 301 rotate to form a single-inclination or multi-inclination, the locking member is used to lock the hinge member 302.

[0068] The smaller the height of the folding frame 301 and the more the number of hinge members 302, the more realistic the fault morphology can be simulated. The specific height of the folding frame 301 and the number of hinge members 302 can be customized according to the test requirements. In this embodiment, taking the minimum number of hinge members 302 as an example, when simulating a fault with double dips, three folding frames 301 and two hinge members 302 should be set. When simulating a fault with triple dips, five folding frames 301 and four hinge members 302 should be set. In addition, this embodiment can also simulate irregular faults. Compared with conventional fault simulation, only the rotation angle between each folding frame 301 needs to be changed.

[0069] Preferably, the hinge member 302 is a pin shaft, and the locking member is a wedge-shaped locking device. The wedge-shaped locking device has the function of quick disassembly and quick assembly, which can save time during the test preparation process. At the same time, the wedge-shaped locking device also has a stable locking function and a small size, which is convenient to be placed in the model box 1 without affecting the test results.

[0070] In this embodiment, the folding frame 301 is a hollow structure, and a filter screen is arranged on its inner frame body. A simulated fault is defined between the filter screens of two adjacent folding skeletons 3.

[0071] In this embodiment, it further includes:

[0072] A prefabricated member 7, made of hard plastic, is an arc-shaped plate structure with an upper opening. A support net is arranged at the upper opening of the prefabricated member 7. The support net is used to support the rock and soil mass above the prefabricated member 7. The prefabricated member 7 is arranged in the model box 1 and penetrates through the folding skeleton 3. Both ends of the prefabricated member 7 extend outside the model box 1;

[0073] A circulation pump. Both ends of the prefabricated member 7 are respectively communicated with the water supply mechanism 5 through a water inlet pipe and a water outlet pipe. The circulation pump is arranged on the water inlet pipe. The circulation pump supplies water into the prefabricated member 7 to form a simulated underground river.

[0074] In this embodiment, it further includes a controller. The controller is electrically connected to the water supply pump and the circulation pump. The controller is used to control the output power of the water supply pump and the circulation pump.

[0075] In this embodiment, it further includes:

[0076] A digital camera 8, arranged outside the model box 1 and corresponding to one end of the tunnel model 4. The digital camera 8 is used to record the entire process of the emergence, development, and occurrence of water and mud gushing from the tunnel face during the whole test process, so as to explore the mechanism of the combined induction of water and mud gushing under strong rainfall conditions when there is a composite fault fracture zone and an underground river in the terrain.

[0077] The present invention also provides a multi-functional test method for a karst area with a fault fracture zone under heavy rainfall, which applies a multi-functional test system for a karst area with a fault fracture zone under heavy rainfall, and includes the following steps:

[0078] S1: Arrange a tunnel model 4 at the bottom of the model box 1. Rotate multiple folding frames 301 to form a folding skeleton 3 with a single inclination angle or multiple inclination angles, and lock the hinge 302 through a locking member.

[0079] S2: Reserve installation holes for the tunnel model 4 and the prefabricated component 7 on the filter net of the folding skeleton 3. Place two folding skeletons 3 in the model box 1, and adjust the distance between the two folding skeletons 3 through the sliding pull rod 6 until the preset width is reached to form a simulated fault.

[0080] S3: Fill the broken rock and soil mass from bottom to top in the simulated fault. At the same time, fill the rock and soil mass in the cavity between the folding skeleton 3 and the inner side wall of the model box 1. When the broken rock and soil mass and the rock and soil mass are filled to the set height of the prefabricated component 7, install the prefabricated component 7; continue to fill the broken rock and soil mass and the rock and soil mass until the top of the model box 1 is reached.

[0081] S4: The controller starts the water supply pump and the circulation pump. The water supply pump and the circulation pump supply water to the rainfall holes 2 and the prefabricated component 7 respectively according to the preset power. The water flow rate of the rainfall holes 2 can be adjusted by adjusting the power of the water supply pump, thereby simulating different rainfall conditions such as light rain, moderate rain, heavy rain and rainstorm. The water flow rate of the underground river can be set by adjusting the power of the circulation pump.

[0082] S5: Collect the lining images of the tunnel model 4 through the digital camera 8.

[0083] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0084] The embodiments described above are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. Multifunctional test system for fault fracture zones in karst areas under heavy rainfall, characterized by: include: The model box (1) is hollow inside and has a plurality of rainwater holes (2) formed on the top through the upper and lower surfaces; A foldable frame (3) is arranged in the model box (1), and a simulated fault with a single or multiple inclination angle is defined between two adjacent foldable frames (3); the simulated fault is filled with broken rock and soil, and the cavity between the foldable frame (3) and the inner wall of the model box (1) is filled with rock and soil; A tunnel model (4) is arranged in the model box (1) and passes through the foldable frame (3), and one end of the tunnel model (4) extends outside the model box (1); A water supply mechanism (5) is connected to the rainwater hole (2) via a delivery pipe, and a water supply pump is provided on the delivery pipe; A sliding pull rod (6) is arranged in the simulated fault, and two ends of the sliding pull rod (6) are respectively connected to two adjacent folding frames (3); the folding frames (3) include: A plurality of folding frames (301), wherein adjacent folding frames (301) are hingedly connected via hinges (302), and the plurality of folding frames (301) are rotated to form a single inclination angle or multiple inclination angles; A locking member, used for locking the hinge member (302) when the multiple folding frames (301) are rotated to form a single inclination angle or multiple inclination angles; The folding frame (301) is a hollow structure, and a filter screen is arranged on the inner frame thereof, and a simulated fault is defined between the filter screens of two adjacent folding frames (3); Also includes: The pre-component (7) is an arc-shaped plate structure with an upper opening, the pre-component (7) is arranged in the model box (1) and passes through the foldable frame (3), and both ends of the pre-component (7) extend outside the model box (1); A circulation pump, wherein both ends of the pre-component (7) are connected to the water supply mechanism (5) via a water inlet pipe and a water outlet pipe respectively, and the circulation pump is arranged on the water inlet pipe, and the circulation pump supplies water into the pre-component (7) to form a simulated dark river.

2. The multifunctional test system for karst areas with fault fracture zones under heavy rainfall according to claim 1 is characterized in that: The hinged member (302) is a pin shaft, and the locking member is a wedge-shaped locking device.

3. The multifunctional test system for karst areas with fault fracture zones under heavy rainfall according to claim 1 is characterized in that: It also includes a controller, which is electrically connected to the water supply pump and the circulation pump, and is used to control the output power of the water supply pump and the circulation pump.

4. The multifunctional test system for karst areas with fault fracture zones under heavy rainfall according to claim 3 is characterized in that: The upper opening of the prefabricated component (7) is provided with a support net, and the support net is used to support the rock and soil body above the prefabricated component (7).

5. The multifunctional test system for karst areas with fault fracture zones under heavy rainfall according to claim 4 is characterized in that: Also includes: A digital camera (8) is arranged outside the model box (1) and corresponds to one end of the tunnel model (4).

6. A multifunctional test method for fault fracture zones in karst areas under heavy rainfall, characterized in that: The multifunctional test system for the fault fracture zone in the karst area under heavy rainfall as claimed in claim 5 comprises the following steps: S1: arranging a tunnel model (4) at the bottom of the model box (1), rotating a plurality of folding frames (301) to form a folding skeleton (3) with a single or multiple inclination angles, and locking the hinged member (302) with a locking member; S2: Reserving installation holes for the tunnel model (4) and the prefabricated component (7) on the filter screen of the foldable frame (3), placing the two foldable frames (3) in the model box (1), and adjusting the distance between the two foldable frames (3) by means of a sliding pull rod (6) until a preset width is reached, thereby forming a simulated fault; S3: Filling the simulated fault with broken rock and soil from bottom to top, and at the same time filling the cavity between the foldable frame (3) and the inner wall of the model box (1) with rock and soil. When the broken rock and soil and the rock and soil are filled to the setting height of the pre-component (7), the pre-component (7) is installed; and the broken rock and soil and the rock and soil are continued to be filled until the top of the model box (1) is reached; S4: the controller starts the water supply pump and the circulation pump, and the water supply pump and the circulation pump supply water to the rainwater hole (2) and the prefabricated component (7) respectively according to the preset power; S5: Collecting a lining image of the tunnel model (4) using a digital camera (8).

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