Similar model sample manufacturing method for high-internal-pressure underground cavern model test
By using removable molds and multi -layer sealing structures in similar model tests of high -pressure underground cave models, the problem of insufficient sealing is solved, and more accurate and secure test results are achieved.
Patent Information
- Application Number
- CN202411463239.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-21
- Publication Date
- 2025-01-28
AI Technical Summary
The prior art is difficult to fully consider the influence of lining and sealing layers in similar model tests for high internal pressure underground cavity models, resulting in insufficient sealing properties and affecting the accuracy and safety of the test.
The detachable molds are used to make the lining model and the surrounding rock model, and the top -based rubber layer is pasted on the inside of the lining layer as a seal layer. The outer surrounding rock is wrapped with polyurethane rubber film.
Improve the sealing of similar model samples, ensure the smooth implementation of the test test of the underground cave model, and enhance the accuracy and safety of the test.
Smart Images
Figure CN119375000A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of compressed air energy storage (compressed gas energy storage), and in particular to a method for preparing a similar model specimen for a high internal pressure underground cave model test. Background Art
[0002] High internal pressure underground cavern energy storage technology faces many technical challenges, including safety control under high internal pressure and repeated temperature effects, and sealing control under long-term operation. Due to the lack of field measured data, the current research on these two key issues of high internal pressure underground energy storage caverns is still mainly at the stage of theoretical analysis and numerical simulation, which restricts the development of high internal pressure underground cavern energy storage technology.
[0003] The basic structure of the high internal pressure underground cavern model includes a lining layer and a sealing layer. The lining layer is set in the underground surrounding rock, and the sealing layer is set on the inner surface of the lining layer. Similar model tests can reveal the stress deformation and failure mechanism of the entire process of underground engineering to a certain extent, and have greater flexibility and economic advantages compared to field tests. However, similar model tests for high internal pressure underground energy storage caverns are very complicated, including the production of similar models. Thai scholar Jongpradist (2015) once designed a similar model test to study the deformation and failure mechanism of the surrounding rock of high internal pressure underground gas storage reservoirs, but the influence of lining and sealing layer was not considered in this test, and the production of similar models was very simple; Zhang Qiangyong's team at Shandong University also designed a three-dimensional similar model test for underground salt rock gas storage reservoirs, but because its research object was salt rock, the lining layer and sealing layer were not considered. However, for high internal pressure underground caverns, lining layer and sealing layer are also key elements. How to take them into account in similar model tests and ensure the good sealing of the model is the key to the success of the test. Summary of the invention
[0004] The technical problem to be solved by the present invention is to provide a method for preparing similar model specimens for high internal pressure underground cavern model tests in view of the shortcomings of the prior art. The method fully considers the flexibility and reusability of the similar model specimen preparation process, and at the same time considers the sealing performance of the similar model specimens, and can fully ensure the smooth implementation of the high internal pressure underground cavern model test.
[0005] The technical solution adopted by the present invention to solve the above technical problems is: a method for preparing a similar model specimen for a high internal pressure underground cavern model test, comprising the following steps:
[0006] 1) Make lining model
[0007] 1.1) Prepare a mold, which includes a lining inner mold, a lining outer mold, a support ring, a cylinder flange, a gasket, a first embedded steel ring and a second embedded steel ring, wherein: the lining inner mold is a cylindrical shape formed by radially splicing a plurality of first circular arc steel plates, the radial outer side of the bottom of each first circular arc steel plate is connected with a first fan-shaped plate, the first fan-shaped plates at the bottom of the plurality of first circular arc steel plates are radially spliced into a connecting ring, the lining outer mold is a cylindrical shape formed by radially splicing a plurality of second circular arc steel plates, a handle is fixed on the outer wall of each second circular arc steel plate, the height of the lining outer mold is less than the height of the lining inner mold, the gasket is a circular ring formed by radially splicing two semicircular ring-shaped steel plates, the upper part of the inner wall of the lining inner mold is tensioned and supported by the support ring, the radial inner side of the first embedded steel ring is connected with a first radially protruding inner ring, and the inner side of the first radially protruding inner ring is connected with a first radially protruding inner ring. The inner diameter of the first radial convex ring is the same as the outer diameter of the lining inner mold, the top of the first embedded steel ring is provided with a first ring groove, the first rubber sealing sleeve is pasted in the first ring groove, the radial inner side of the second embedded steel ring is connected with a second radial convex ring protruding downward, the inner diameter of the second radial convex ring is the same as the outer diameter of the lining inner mold, the bottom of the second embedded steel ring is provided with a second ring groove, the second rubber sealing sleeve is pasted in the second ring groove, the cylinder flange is fixed to the lower side of the connecting ring by bolts, the gasket is stacked on the upper side of the connecting ring, the first embedded steel ring is stacked on the upper side of the gasket, the lining outer mold is placed upright, the bottom end of the lining outer mold is in sealing contact with the first rubber sealing sleeve, the outer surface of the lining inner mold, the inner surface of the lining outer mold, the top surface of the first embedded steel ring and the outer surface of the first radial convex ring form an annular mold cavity with an opening at the top;
[0008] 1.2) pouring the prepared lining-like material into the annular mold cavity from the top of the annular mold cavity until the lining-like material is flush with the top of the lining outer mold, and then placing the second embedded steel ring on the lining outer mold, so that the top of the lining outer mold is in sealing contact with the second rubber sealing sleeve, and at the same time, the second radial convex ring is inserted into the lining-like material in the annular mold cavity, and the lining-like material in the annular mold cavity solidifies, and the solidified lining-like material is the lining layer, and the lining outer mold and the pad are removed to obtain a lining model;
[0009] 2) Make surrounding rock model
[0010] A model test box is prepared, which is a rectangular parallelepiped constructed by a plurality of templates, the lining model is placed across the middle of the model test box, and the prepared surrounding rock-like material is poured into the model test box so that the poured surrounding rock-like material surrounds the outer surface of the lining layer, and at the same time, a plurality of sensors are buried in the surrounding rock-like material that has not yet completely solidified, and a plurality of threading holes for routing the sensors are set, after the surrounding rock-like material in the model test box solidifies, the solidified surrounding rock-like material is the surrounding rock, and the plurality of templates, the lining inner mold, the cylinder flange and the support ring are removed to obtain a surrounding rock model with a lining layer;
[0011] 3) Make a sealing layer
[0012] A 3 mm thick butyl rubber layer is pasted on the inner surface of the lining layer as a sealing layer, and the two ends of the butyl rubber layer are respectively bonded to the inner surfaces of the first radial convex ring and the second radial convex ring. Finally, a layer of polyurethane rubber film is wrapped around the outer side of the surrounding rock as a whole, so as to obtain a similar model specimen for the high internal pressure underground cave model test.
[0013] The similar model specimen preparation method of the present invention has the following characteristics:
[0014] (1) Convenient mold construction and removal: The present invention adopts a detachable lining inner mold and lining outer mold, wherein the lining inner mold is radially spliced by a plurality of first circular arc steel plates, and the lining outer mold is radially spliced by a plurality of second circular arc steel plates. In order to keep the mold fixed during the casting process, the plurality of first circular arc steel plates are connected as a whole through the cylinder flange. When the mold is removed, the bolts connecting the cylinder flange and the connecting ring are removed, and after the cylinder flange is removed, the first circular arc steel plate can be taken out in petals; the bottom end of the lining outer mold is inserted into the first ring groove and in sealing contact with the first rubber sealing sleeve, and the top end is inserted into the second ring groove and in sealing contact with the second rubber sealing sleeve. When the lining outer mold is removed, the second circular arc steel plate can be taken out in petals by holding the handle and pulling it outward with a little force;
[0015] (2) The similar model specimens prepared have good sealing performance: First, in order to ensure that the high-pressure air in the cavern will not leak out from the overlap between the lining layer and the surrounding rock, the present invention designs a first embedded steel ring and a second embedded steel ring. The first radial convex ring on the inner side of the first embedded steel ring and the second radial convex ring on the inner side of the second embedded steel ring protrude into the lining layer to a certain depth, which can fully ensure the close contact between the first embedded steel ring and the second embedded steel ring and the lining layer, so that the first embedded steel ring and the second embedded steel ring are connected to the lining layer as a whole. In addition, the first embedded steel ring and the second embedded steel ring are provided with a plurality of radial protrusions, and ... The steel ring is provided with a first annular groove and a second annular groove, and a first rubber sealing sleeve and a second rubber sealing sleeve are pasted in the first annular groove and the second annular groove respectively. During the test, the cylinder flange ensures that the high-pressure air in the cavern will not leak out from the junction of the lining inner mold and the cylinder flange; secondly, in order to ensure that the high-pressure air in the cavern will not leak out along the inner surface of the lining layer, a 3mm thick butyl rubber layer is pasted on the inner surface of the lining layer as a sealing layer; thirdly, by wrapping a layer of polyurethane rubber film on the outer side of the surrounding rock as a whole, the overall sealing of the similar model specimen is fully guaranteed.
[0016] Preferably, the templates on the front and rear sides of the model test box are respectively composed of multiple sub-templates, and the multiple sub-templates are divided into upper sub-templates, middle sub-templates and lower sub-templates, which are spliced in sequence. The middle sub-template is provided with a window, and the lining model is horizontally mounted on the middle sub-template. The first embedded steel ring and the second embedded steel ring are respectively located on the outside of the window. The surrounding rock-similar material is poured into the model test box by a layered pouring method, that is, first support the lower sub-template, and pour the lower part of the model test box. The surrounding rock-like materials of the lower layer, after the surrounding rock-like materials of the lower layer solidify, the middle layer sub-template is supported on the lower layer sub-template, and then the lining model is horizontally placed on the middle layer sub-template, and then the middle layer surrounding rock-like materials are poured into the middle of the model test box so that the middle layer surrounding rock-like materials surround the outer surface of the lining layer, and after the middle layer surrounding rock-like materials solidify, the upper layer sub-template is supported on the middle layer sub-template, and then the upper layer surrounding rock-like materials are poured into the upper part of the model test box, and after the upper layer surrounding rock-like materials solidify, the surrounding rock is obtained. The above-mentioned layered multi-block sub-template design facilitates the pre-embedding of sensors at different positions of the surrounding rock to ensure the accuracy of the high internal pressure underground cavern model test results.
[0017] As a further preference, the multiple sub-templates include a first-layer sub-template, a second-layer sub-template, a third-layer sub-template, a fourth-layer sub-template, a fifth-layer sub-template and a sixth-layer sub-template connected in sequence from bottom to top; the first-layer sub-template and the second-layer sub-template are spliced to form the lower-layer sub-template, the third-layer sub-template and the fourth-layer sub-template are spliced to form the middle-layer sub-template, and the fourth-layer sub-template and the fifth-layer sub-template are spliced to form the upper-layer sub-template.
[0018] Preferably, the lining inner mold is a cylinder formed by radially splicing eight petals of first arc-shaped steel plates, and the lining outer mold is a cylinder formed by radially splicing four petals of second arc-shaped steel plates. The outer surface of the lining inner mold and the inner surface of the lining outer mold are pre-coated with release agent respectively.
[0019] Compared with the prior art, the present invention has the following advantages:
[0020] 1. The similar model sample manufacturing method of the present invention fully considers the flexibility and reusability of the similar model sample manufacturing process, and at the same time considers the sealing performance of the similar model sample, which can fully guarantee the smooth implementation of the high internal pressure underground cave model test; the present invention can fully guarantee the sealing performance of the similar model sample as a whole by designing a sealing structure composed of a first embedded steel ring, a second embedded steel ring, a first rubber sealing sleeve, a second rubber sealing sleeve, a sealing layer, and a polyurethane rubber film;
[0021] 2. The similar model specimen preparation method of the present invention builds a special detachable mold. During casting, the lining inner mold and the lining outer mold are overlapped with the cylinder flange, the first embedded steel ring and the second embedded steel ring to ensure the integrity of the mold. During dismantling, the bolts connecting the cylinder flange and the connecting ring are removed, and the cylinder flange, the multi-petal first circular arc steel plate, etc. can be easily dismantled. In addition, the dismantling operation of the multi-petal second circular arc steel plate, the pad, the support ring, and the template is also relatively convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] Figure 1 This is a schematic diagram of the appearance of the lining model before the lining outer mold and the backing plate are removed in the embodiment;
[0023] Figure 2 To correspond to Figure 1 Schematic diagram of longitudinal section;
[0024] Figure 3 for Figure 2 Enlarged view of point A in the middle;
[0025] Figure 4 for Figure 2 Enlarged view of point B in the middle;
[0026] Figure 5 It is a schematic diagram of the assembly effect of the lining model and the model test box before removing multiple templates, lining inner molds, cylinder flanges and support rings in the embodiment;
[0027] 1-lining inner mold, 11-first arc-shaped steel plate, 12-connecting ring, 2-lining outer mold, 21-second arc-shaped steel plate, 3-support ring, 4-cylinder flange, 5-gasket, 6-first embedded steel ring, 61-first radial convex ring, 62-first annular groove, 63-annular mold cavity, 7-second embedded steel ring, 71-second radial convex ring, 72-second annular groove, 8-model test box, 81-first layer sub-template, 82-second layer sub-template, 83-third layer sub-template, 84-fourth layer sub-template, 85-fifth layer sub-template, 86-sixth layer sub-template, 87-window, 88-threading hole. DETAILED DESCRIPTION
[0028] The present invention is further described in detail below with reference to the accompanying drawings.
[0029] Embodiment: A method for preparing a similar model specimen for a high internal pressure underground cavern model test, characterized in that it comprises the following steps:
[0030] 1) Make lining model
[0031] 1.1) Prepare a mold, such as Figure 1-Figure 4As shown, the mold includes a lining inner mold 1, a lining outer mold 2, a support ring 3, a cylinder flange 4, a gasket 5, a first embedded steel ring 6 and a second embedded steel ring 7, wherein: the lining inner mold 1 is a cylindrical shape formed by radially splicing 8 petals of first circular arc steel plates 11, and the radial outer side of the bottom of each petal of the first circular arc steel plate 11 is connected with a first sector plate, and the first sector plates at the bottom of the 8 petals of the first circular arc steel plates 11 are radially spliced into a connecting ring 12, and the lining outer mold 2 is a cylindrical shape formed by radially splicing 4 petals of the second circular arc steel plates 21 The outer wall of each second arc-shaped steel plate 21 is fixed with a handle (not shown in the figure). The height of the lining outer mold 2 is less than the height of the lining inner mold 1. The outer surface of the lining inner mold 1 and the inner surface of the lining outer mold 2 are pre-coated with a release agent. The pad 5 is a circular ring formed by radially splicing two semicircular ring steel plates. The upper part of the inner wall of the lining inner mold 1 is supported by the support ring 3. The radial inner side of the first embedded steel ring 6 is connected with a second protruding upward with a height of 40 mm. A radial convex ring 61, the inner diameter of the first radial convex ring 61 is the same as the outer diameter of the inner lining mold 1, the top of the first embedded steel ring 6 is provided with a first annular groove 62, and a first rubber sealing sleeve (not shown in the figure) is pasted in the first annular groove 62, and a second radial convex ring 71 with a downward protrusion height of 40 mm is connected to the radial inner side of the second embedded steel ring 7, the inner diameter of the second radial convex ring 71 is the same as the outer diameter of the inner lining mold 1, and a second annular groove 72 is provided at the bottom of the second embedded steel ring 7, and a second annular groove 72 is provided in the second annular groove 72. A second rubber sealing sleeve (not shown in the figure) is pasted, the cylinder flange 4 is fixed to the lower side of the connecting ring 12 by bolts, the gasket 5 is stacked on the upper side of the connecting ring 12, the first embedded steel ring 6 is stacked on the upper side of the gasket 5, the lining outer mold 2 is placed upright, the bottom end of the lining outer mold 2 is in sealing contact with the first rubber sealing sleeve, and the outer surface of the lining inner mold 1, the inner surface of the lining outer mold 2, the top surface of the first embedded steel ring 6 and the outer surface of the first radial convex ring 61 form an annular mold cavity 63 with an opening at the top;
[0032] 1.2) Pour the prepared lining-like material into the annular mold cavity 63 from the top of the annular mold cavity 63 until the lining-like material is flush with the top of the lining outer mold 2, then place the second embedded steel ring 7 on the lining outer mold 2, so that the top of the lining outer mold 2 is in sealing contact with the second rubber sealing sleeve, and at the same time, insert the second radial convex ring 71 into the lining-like material in the annular mold cavity 63, wait for the lining-like material in the annular mold cavity 63 to solidify, and the solidified lining-like material is the lining layer, remove the lining outer mold 2 and the pad 5, and obtain the lining model;
[0033] 2) Make surrounding rock model
[0034] A model test box 8 is prepared. The model test box 8 is a rectangular parallelepiped constructed by multiple templates. The templates on the front and rear sides of the model test box 8 are respectively composed of multiple sub-templates. The multiple sub-templates are divided into upper sub-templates, middle sub-templates and lower sub-templates, which are spliced in sequence. A window 87 is opened on the middle sub-template. The lining model is adjusted to the middle of the model test box 8 by using a gantry crane and placed across the middle of the model test box 8, so that the lining model is horizontally mounted on the middle sub-template. The first embedded steel ring 6 and the second embedded steel ring 7 are respectively located on the outside of the window 87. Specifically, the multiple sub-templates include a first-layer sub-template 81, a second-layer sub-template 82, a third-layer sub-template 83, a fourth-layer sub-template 84, a fifth-layer sub-template 85 and a sixth-layer sub-template 86 connected in sequence from bottom to top. The first-layer sub-template 81 and the second-layer sub-template 82 are spliced to form the lower sub-template, the third-layer sub-template 83 and the fourth-layer sub-template 84 are spliced to form the middle sub-template, and the fourth-layer sub-template The sub-template 84 and the fifth layer 85 are spliced to form the sub-template of the upper layer. The surrounding rock-like material is poured into the model test box 8 by a layered pouring method. At the same time, a number of sensors (not shown in the figure) are buried in the surrounding rock-like material that has not yet completely solidified, and a number of threading holes 88 for routing the sensors are set. The process of layered pouring is as follows: first, the sub-template of the lower layer is supported, and the surrounding rock-like material of the lower layer is poured into the lower part of the model test box 8. After the surrounding rock-like material of the lower layer solidifies, the sub-template of the middle layer is supported on the sub-template of the lower layer, and then the lining model is placed horizontally on the sub-template of the middle layer. Subsequently, the surrounding rock-like material of the middle layer is poured into the middle part of the model test box 8, so that the surrounding rock-like material of the middle layer surrounds the outer surface of the lining layer. After the surrounding rock-like material of the middle layer solidifies, the sub-template of the upper layer is supported on the sub-template of the middle layer. Thereafter, the surrounding rock-like material of the upper layer is poured into the upper part of the model test box 8. After the surrounding rock-like material of the upper layer solidifies, all the solidified surrounding rock-like material in the model test box 8 is the surrounding rock. The state diagram at this time is shown in FIG. Figure 5 , and then remove the multiple templates, the lining inner mold 1, the cylinder flange 4 and the support ring 3 to obtain the surrounding rock model with the lining layer;
[0035] 3) Make a sealing layer
[0036] A 3 mm thick butyl rubber layer is pasted on the inner surface of the lining layer as a sealing layer, and the two ends of the butyl rubber layer are respectively bonded to the inner surfaces of the first radial convex ring 61 and the second radial convex ring 71. Finally, a layer of polyurethane rubber film is wrapped around the outer side of the surrounding rock as a whole, so as to obtain a similar model specimen for the high internal pressure underground cave model test.
[0037] The above-mentioned similar model specimen production method designs a sealing structure by designing a first embedded steel ring, a second embedded steel ring, a first rubber sealing sleeve, a second rubber sealing sleeve, a sealing layer, and a polyurethane rubber film, and adopts a mold that is easy to assemble and dismantle and can be reused. The production process is flexible, and the similar model specimens produced have good sealing properties, which can fully guarantee the overall sealing properties of the similar model specimens and can fully guarantee the smooth implementation of the high internal pressure underground cavern model test.
Claims
1. A method for preparing a similar model specimen for a high internal pressure underground cavern model test, characterized in that: The following steps are involved: 1) Make lining model 1.1) Prepare a mold, which includes a lining inner mold, a lining outer mold, a support ring, a cylinder flange, a gasket, a first embedded steel ring and a second embedded steel ring, wherein: the lining inner mold is a cylindrical shape formed by radially splicing a plurality of first circular arc steel plates, the radial outer side of the bottom of each first circular arc steel plate is connected with a first fan-shaped plate, the first fan-shaped plates at the bottom of the plurality of first circular arc steel plates are radially spliced into a connecting ring, the lining outer mold is a cylindrical shape formed by radially splicing a plurality of second circular arc steel plates, a handle is fixed on the outer wall of each second circular arc steel plate, the height of the lining outer mold is less than the height of the lining inner mold, the gasket is a circular ring formed by radially splicing two semicircular ring-shaped steel plates, the upper part of the inner wall of the lining inner mold is tensioned and supported by the support ring, the radial inner side of the first embedded steel ring is connected with a first radially protruding inner ring, and the inner side of the first radially protruding inner ring is connected with a first radially protruding inner ring. The inner diameter of the first radial convex ring is the same as the outer diameter of the lining inner mold, the top of the first embedded steel ring is provided with a first ring groove, the first rubber sealing sleeve is pasted in the first ring groove, the radial inner side of the second embedded steel ring is connected with a second radial convex ring protruding downward, the inner diameter of the second radial convex ring is the same as the outer diameter of the lining inner mold, the bottom of the second embedded steel ring is provided with a second ring groove, the second rubber sealing sleeve is pasted in the second ring groove, the cylinder flange is fixed to the lower side of the connecting ring by bolts, the gasket is stacked on the upper side of the connecting ring, the first embedded steel ring is stacked on the upper side of the gasket, the lining outer mold is placed upright, the bottom end of the lining outer mold is in sealing contact with the first rubber sealing sleeve, the outer surface of the lining inner mold, the inner surface of the lining outer mold, the top surface of the first embedded steel ring and the outer surface of the first radial convex ring form an annular mold cavity with an opening at the top; 1.2) pouring the prepared lining-like material into the annular mold cavity from the top of the annular mold cavity until the lining-like material is flush with the top of the lining outer mold, and then placing the second embedded steel ring on the lining outer mold, so that the top of the lining outer mold is in sealing contact with the second rubber sealing sleeve, and at the same time, the second radial convex ring is inserted into the lining-like material in the annular mold cavity, and the lining-like material in the annular mold cavity solidifies, and the solidified lining-like material is the lining layer, and the lining outer mold and the pad are removed to obtain a lining model; 2) Make surrounding rock model A model test box is prepared, which is a rectangular parallelepiped constructed by a plurality of templates, the lining model is placed across the middle of the model test box, and the prepared surrounding rock-like material is poured into the model test box so that the poured surrounding rock-like material surrounds the outer surface of the lining layer, and at the same time, a plurality of sensors are buried in the surrounding rock-like material that has not yet completely solidified, and a plurality of threading holes for routing the sensors are set, after the surrounding rock-like material in the model test box solidifies, the solidified surrounding rock-like material is the surrounding rock, and the plurality of templates, the lining inner mold, the cylinder flange and the support ring are removed to obtain a surrounding rock model with a lining layer; 3) Make a sealing layer A 3 mm thick butyl rubber layer is pasted on the inner surface of the lining layer as a sealing layer, and the two ends of the butyl rubber layer are respectively bonded to the inner surfaces of the first radial convex ring and the second radial convex ring. Finally, a layer of polyurethane rubber film is wrapped around the outer side of the surrounding rock as a whole, so as to obtain a similar model specimen for the high internal pressure underground cave model test.
2. The method for preparing a similar model specimen for a high internal pressure underground cavern model test according to claim 1, characterized in that: The templates on the front and rear sides of the model test box are respectively composed of multiple sub-templates, and the multiple sub-templates are divided into upper sub-templates, middle sub-templates and lower sub-templates, which are spliced in sequence. The middle sub-template is provided with a window, and the lining model is horizontally mounted on the middle sub-template. The first embedded steel ring and the second embedded steel ring are respectively located on the outside of the window. The surrounding rock similar material is poured into the model test box by a layered pouring method, that is, first support the lower sub-template, and pour the lower sub-template into the lower part of the model test box. The surrounding rock-like material, after the surrounding rock-like material of the lower layer solidifies, the middle layer sub-formwork is supported on the lower layer sub-formwork, and then the lining model is horizontally placed on the middle layer sub-formwork, and then the middle layer surrounding rock-like material is poured into the middle part of the model test box, so that the middle layer surrounding rock-like material surrounds the outer surface of the lining layer, and after the surrounding rock-like material of the middle layer solidifies, the upper layer sub-formwork is supported on the middle layer sub-formwork, and then the upper layer surrounding rock-like material is poured into the upper part of the model test box, and after the upper layer surrounding rock-like material solidifies, the surrounding rock is obtained.
3. The method for preparing a similar model specimen for a high internal pressure underground cavern model test according to claim 2, characterized in that: The multiple sub-templates include a first-layer sub-template, a second-layer sub-template, a third-layer sub-template, a fourth-layer sub-template, a fifth-layer sub-template and a sixth-layer sub-template connected in sequence from bottom to top; the first-layer sub-template and the second-layer sub-template are spliced to form the lower-layer sub-template, the third-layer sub-template and the fourth-layer sub-template are spliced to form the middle-layer sub-template, and the fourth-layer sub-template and the fifth-layer sub-template are spliced to form the upper-layer sub-template.
4. The method for preparing a similar model specimen for a high internal pressure underground cavern model test according to claim 1, characterized in that: The inner lining mold is a cylinder formed by radially splicing eight first arc-shaped steel plates, and the outer lining mold is a cylinder formed by radially splicing four second arc-shaped steel plates. The outer surface of the inner lining mold and the inner surface of the outer lining mold are pre-coated with release agents respectively.