Karst tunnel cave similar simulation experiment device for applying different gradient stresses

Abstract

This invention discloses a karst tunnel cave simulation experimental device for applying different gradient stresses. The device includes a first loading chamber, a second loading chamber, a third loading chamber, a top cover, a first oil pump, a second oil pump, a third oil pump, a first pressure regulating valve, a second pressure regulating valve, a third pressure regulating valve, a first strain gauge, a second strain gauge, a third strain gauge, and a high-speed camera mounted on the top cover. This karst tunnel cave simulation experimental device can apply different pressures to the lower, middle, and upper parts of a hollow rock specimen, thereby simulating the force exerted by different soil pressures at different burial depths on the cave. It can also observe and record the deformation and failure of the specimen using strain sensors and a high-speed camera. This device can conveniently simulate the structural changes of caves under stress gradients in engineering projects.

Description

Technical Field

[0001] This invention relates to the field of simulation experimental device technology, and in particular to a karst tunnel cave simulation experimental device. Background Technology

[0002] Karst caves are a type of karst phenomenon. When tunnels pass through soluble rock layers, some caves have fractured rock and are prone to collapse. Other caves are located at the bottom of tunnels, with soft and deep filling materials, making the tunnel foundation difficult to treat. Therefore, it is important to study the structural stability of karst caves.

[0003] Similarity simulation is an important scientific research method. By creating a model similar to the prototype in the laboratory according to the principle of similarity, and using testing instruments to observe the mechanical parameters and their distribution in the model, the results of the study on the model can be used to infer the mechanical phenomena that may occur in the prototype and the law of rock mass pressure distribution, thereby solving practical problems in rock mass engineering production.

[0004] However, similar simulation experimental devices in the prior art, although they can apply forces to rock specimens in the up-down, front-back, left-right directions to simulate the actual stress conditions of the rock mass, simulate the same magnitude of force in the same direction. They cannot simulate the stress gradient of the rock mass in the height direction of the specimen. For example, the three-dimensional physical simulation experimental device disclosed in the patent application number 202011040652X cannot simulate different stress gradients in the height direction of the specimen. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a karst tunnel cave similarity simulation experimental device for applying different gradient stresses, so as to solve the technical problem of simulating the gradient stress borne by the rock specimen in the height direction of the specimen, thereby simulating the force of different soil pressures on the cave at different burial depths.

[0006] The present invention provides a karst tunnel cave similarity simulation experimental device for applying different gradient stresses, comprising a first loading cavity, a second loading cavity connected to the first loading cavity by screws, a third loading cavity connected to the second loading cavity by screws, a cavity cover connected to the third loading cavity by screws, and a top cover connected to the cavity cover by bolts. A circular hole for inserting a hollow rock specimen is provided in the middle of the first, second, third, and cavity covers. A sealing ring is provided on the inner wall of the circular hole. A first sealing gasket is provided between the first and second loading cavities, a second sealing gasket is provided between the second and third loading cavities, and a third sealing gasket is provided between the third loading cavity and the cavity cover.

[0007] The karst tunnel simulation experimental device with different gradient stresses further includes a first oil inlet connector on the first loading chamber, a second oil inlet connector on the second loading chamber, a third oil inlet connector on the third loading chamber, a first oil pump, a second oil pump, a third oil pump, a first oil inlet pipe connecting the outlet of the first oil pump and the first oil inlet connector, a second oil inlet pipe connecting the outlet of the second oil pump and the second oil inlet connector, a third oil inlet pipe connecting the outlet of the third oil pump and the third oil inlet connector, and oil inlet pipes connecting the first oil pump, the second oil pump, and the third oil pump. The system comprises a first oil tank, a first oil outlet connector on the first loading cavity, a second oil outlet connector on the second loading cavity, a third oil outlet connector on the third loading cavity, a first oil drain pipe connected to the first oil outlet connector, a first pressure regulating valve on the first oil drain pipe, a second oil drain pipe connected to the second oil outlet connector, a second pressure regulating valve on the second oil drain pipe, a third oil drain pipe connected to the third oil outlet connector, a third pressure regulating valve on the third oil drain pipe, and a second oil tank connected to the first oil drain pipe, the first oil drain pipe, and the third oil drain pipe.

[0008] The karst tunnel and cavern similarity simulation experimental device with different gradient stresses also includes a first pressure sensor on the first loading cavity, a second pressure sensor on the second loading cavity, a third pressure sensor on the third loading cavity, a first strain gauge on the lower part of the hollow rock specimen, a second strain gauge on the middle part of the hollow rock specimen, a third strain gauge on the upper part of the hollow rock specimen, a high-speed camera on the top cover, and a light source on the top cover.

[0009] Furthermore, the first loading cavity, the second loading cavity, and the third loading cavity are rectangular or circular concave cavities.

[0010] The beneficial effects of this invention are:

[0011] This invention provides a karst tunnel simulation experimental device that applies different gradient stresses. It can apply different pressures to the lower, middle and upper parts of a hollow rock specimen, thereby simulating the force of different soil pressures on the karst cave at different burial depths. It can also observe and record the deformation and failure of the specimen through strain sensors and high-speed cameras. This device can conveniently simulate the structural changes of karst caves under stress gradients in engineering projects. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the karst tunnel cave simulation experimental device for applying different gradient stresses according to the present invention. Detailed Implementation

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] As shown in the figure, the karst tunnel simulation experimental device for applying different gradient stresses in this embodiment includes a first loading cavity 1, a second loading cavity 2 connected to the first loading cavity by screws, a third loading cavity 3 connected to the second loading cavity by screws, a cavity cover 4 connected to the third loading cavity by screws, and a top cover 5 connected to the cavity cover by bolts. A circular hole for inserting a hollow rock specimen 38 is provided in the middle of the first, second, and third loading cavities and the cavity cover. A sealing ring 6 is provided on the inner wall of the circular hole. A first sealing gasket 7 is provided between the first and second loading cavities, a second sealing gasket 8 is provided between the second and third loading cavities, and a third sealing gasket 9 is provided between the third loading cavity and the cavity cover. The first, second, and third loading cavities are rectangular concave cavities; however, in different embodiments, they can also be circular concave cavities.

[0015] The karst tunnel and cavern similarity simulation experimental device with different gradient stresses further includes a first oil inlet connector 10 on the first loading chamber, a second oil inlet connector 11 on the second loading chamber, a third oil inlet connector 12 on the third loading chamber, a first oil pump 13, a second oil pump 14, a third oil pump 15, a first oil inlet pipe 16 connecting the outlet of the first oil pump and the first oil inlet connector, a second oil inlet pipe 17 connecting the outlet of the second oil pump and the second oil inlet connector, a third oil inlet pipe 18 connecting the outlet of the third oil pump and the third oil inlet connector, and an oil inlet pipe connected to the first oil pump, the second oil pump, and the third oil pump. The first oil tank 19, the first oil outlet connector 20 provided on the first layer loading cavity, the second oil outlet connector 21 provided on the second layer loading cavity, the third oil outlet connector 22 provided on the third layer loading cavity, the first oil drain pipe 23 connected to the first oil outlet connector, the first pressure regulating valve 24 provided on the first oil drain pipe, the second oil drain pipe 25 connected to the second oil outlet connector, the second pressure regulating valve 26 provided on the second oil drain pipe, the third oil drain pipe 27 connected to the third oil outlet connector, the third pressure regulating valve 28 provided on the third oil drain pipe, and the second oil tank 29 connected to the first oil drain pipe, the first oil drain pipe and the third oil drain pipe.

[0016] The karst tunnel cave simulation experimental device with different gradient stresses also includes a first pressure sensor 30 on the first loading cavity, a second pressure sensor 31 on the second loading cavity, a third pressure sensor 32 on the third loading cavity, a first strain gauge 33 on the lower part of the hollow rock specimen, a second strain gauge 34 on the middle part of the hollow rock specimen, a third strain gauge 35 on the upper part of the hollow rock specimen, a high-speed camera 36 on the top cover, and a light source 37 on the top cover.

[0017] This embodiment presents a karst tunnel simulation experimental device that applies different gradient stresses. Three oil pumps pump loading oil into three loading cavities, and three pressure regulating valves independently adjust the oil pressure within each cavity. This simulates the forces exerted on the karst cave by different soil pressures at varying burial depths. Furthermore, a high-speed camera and three strain sensors record the deformation and failure of the specimens during the experiment. This device can conveniently simulate the structural changes of karst caves under stress gradients in engineering projects.

[0018] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A karst tunnel cave similar simulation experiment device for applying different gradient stresses, characterized in that: The device comprises a first layer loading cavity, a second layer loading cavity connected to the first layer loading cavity by screws, a third layer loading cavity connected to the second layer loading cavity by screws, a cavity cover connected to the third layer loading cavity by screws, and a top cover connected to the cavity cover by bolts, the middle part of the first layer loading cavity, the second layer loading cavity, the third layer loading cavity and the cavity cover is provided with a circular hole for placing a hollow rock sample, a sealing rubber ring is arranged on the inner wall of the circular hole, a first sealing gasket is arranged between the first layer loading cavity and the second layer loading cavity, a second sealing gasket is arranged between the second layer loading cavity and the third layer loading cavity, and a third sealing gasket is arranged between the third layer loading cavity and the cavity cover. The karst tunnel cave similar simulation experiment device for applying different gradient stresses further comprises a first oil inlet joint arranged on the first layer loading cavity, a second oil inlet joint arranged on the second layer loading cavity, a third oil inlet joint arranged on the third layer loading cavity, a first oil pump, a second oil pump, a third oil pump, a first oil inlet pipe connecting the outlet of the first oil pump and the first oil inlet joint, a second oil inlet pipe connecting the outlet of the second oil pump and the second oil inlet joint, a third oil inlet pipe connecting the outlet of the third oil pump and the third oil inlet joint, a first oil tank connected to the oil inlet pipes of the first oil pump, the second oil pump and the third oil pump, a first oil outlet joint arranged on the first layer loading cavity, a second oil outlet joint arranged on the second layer loading cavity, a third oil outlet joint arranged on the third layer loading cavity, a first oil outlet pipe connected to the first oil outlet joint, a first pressure regulating valve arranged on the first oil outlet pipe, a second oil outlet pipe connected to the second oil outlet joint, a second pressure regulating valve arranged on the second oil outlet pipe, a third oil outlet pipe connected to the third oil outlet joint, a third pressure regulating valve arranged on the third oil outlet pipe, and a second oil tank connected to the first oil outlet pipe, the first oil outlet pipe and the third oil outlet pipe. The karst tunnel cave similar simulation experiment device for applying different gradient stresses further comprises a first pressure sensor arranged on the first layer loading cavity, a second pressure sensor arranged on the second layer loading cavity, a third pressure sensor arranged on the third layer loading cavity, a first strain gauge arranged at the lower part of the hollow rock sample, a second strain gauge arranged at the middle part of the hollow rock sample, a third strain gauge arranged at the upper part of the hollow rock sample, a high-speed camera arranged on the top cover, and a light source arranged on the top cover.

2. The karst tunnel cavity similar simulation experiment device of applying different gradient stresses according to claim 1, characterized in that: The first layer loading cavity, the second layer loading cavity and the third layer loading cavity are rectangular concave cavities or circular concave cavities.

Images