Solid-liquid phase change simulation method for meltable excavation body and multi-step excavation

Abstract

The application discloses a kind of melt excavation body and the solid-liquid phase change simulation method of multi-step excavation, the melt excavation body includes several melt excavation modules and several isolation layers, any two melt excavation modules are adjacent spliced by an isolation layer to form the melt excavation body.Compared with prior art, the melt excavation body is used to replace original rock in the application, and the solid-liquid phase change simulation of multi-step excavation is carried out, which has the advantages of simulating the deformation characteristics of real original surrounding rock, getting rid of the limitation of tunnel shape, realizing segmented excavation, and controlling excavation rate.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of tunnel engineering test, in particular to a meltable excavation body and a solid-liquid phase change simulation method for multi-step excavation. BACKGROUND

[0002] With the rapid development of tunnels, the buried depth of tunnel alignment is getting deeper and the geological environment is getting more complex, and the selected tunnel shape and excavation method are also more and more various, and different excavation methods also have different disturbance forms to the surrounding rock and soil, which puts forward more stringent requirements for indoor tunnel excavation simulation. Indoor model test is a research method based on similarity theory for evaluating the performance and behavior of engineering structures in practical application. Compared with traditional empirical theory formula and numerical simulation, indoor model test can more intuitively reflect the stress and deformation mechanism, failure mechanism and instability of engineering structures and related rock and soil under the action of rock and soil. In the tunnel engineering related model test, tunnel excavation simulation is the key to the equivalent reduction of the actual engineering.

[0003] Tunnel excavation simulation generally has two ways: manual excavation and mechanical excavation. Manual excavation can flexibly adjust the shape of the tunnel, but the forming effect is poor, the excavation efficiency is low, the model test is limited, and the engineering disturbance is large; while mechanical excavation is simple to operate, good in forming, and high in efficiency, but the shape is mostly limited to circular. In addition, there are unloading excavation and blasting excavation in indoor tunnel excavation simulation. The blasting method uses gunpowder or related blasting technology to blast the test model, corresponding to the drilling and blasting method in tunnel engineering, but due to safety, controllability, environmental protection and other considerations, it is less used in the laboratory. Unloading excavation can also simulate the transient unloading of drilling and blasting, and reduce the disturbance of blasting to the surrounding rock of the tunnel. The unloading excavation restores the original rock stress state by precasting the tunnel model, and then unloads the pressure in the tunnel to simulate the tunnel excavation process. The unloading process usually uses special test instruments or similar materials to achieve. At present, most of the indoor unloading excavation simulation systems of tunnels use hydraulic oil and force transmission plates or special molds as excavation simulation objects, that is, the part to be excavated is replaced by a mold in advance, and the excavation is simulated by unloading the hydraulic oil or removing the mold. This can simulate the excavation to some extent, but there is a big difference between the strength and stiffness of the excavation simulation object and the original surrounding rock, which cannot simulate the true deformation characteristics of the original rock, and the strength and stiffness of the excavation simulation object are constant and single, which cannot meet the application requirements of different original rocks and ground stress states. At the same time, due to the different excavation sequences, different excavation methods require different tunnel excavation simulation conditions, and the existing excavation simulation system is mainly designed for a certain excavation method, which is not flexible in application scope.

[0004] Therefore, how to provide a simulation method for irregular section excavation, so as to achieve the technical effects of simulating the real original surrounding rock deformation characteristics, getting rid of the restriction of tunnel shape, realizing segmented excavation, and controlling the excavation rate, is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0005] In view of the problems in the prior art, the technical problem to be solved by the present application is to provide a meltable excavation body and a solid-liquid phase change simulation method for multi-step excavation, so as to achieve the technical effects of simulating the real original surrounding rock deformation characteristics, getting rid of the restriction of tunnel shape, realizing segmented excavation, and controlling the excavation rate.

[0006] To achieve the above-mentioned purpose, the first aspect of the present application provides a meltable excavation body, which comprises: a plurality of meltable excavation modules and a plurality of isolation layers, any two meltable excavation modules being adjacent to each other and spliced by an isolation layer to form the meltable excavation body, each meltable excavation module comprising: a meltable material, a flexible waterproof thermal insulation layer, a rigid outer protective layer, and a waterproof heater corresponding to the number of meltable excavation units; wherein the flexible waterproof thermal insulation layer comprises a first waterproof thermal insulation layer and a second waterproof thermal insulation layer, the first waterproof thermal insulation layer and the isolation layers on both sides of the meltable excavation module correspondingly form a containing space, the meltable material is filled in the containing space, the second waterproof thermal insulation layer is arranged in the meltable material and sequentially divides the meltable excavation module in the transverse direction and the longitudinal direction of the meltable excavation module to form a plurality of independent meltable excavation units; the rigid outer protective layer is arranged on the outer peripheral part of the first waterproof thermal insulation layer; each waterproof heater is correspondingly arranged in one meltable excavation unit.

[0007] In the first aspect, the rigid outer protective layer comprises: a first half protective layer assembly and a second half protective layer assembly, the first half protective layer assembly and the second half protective layer assembly are detachably connected by a first connecting assembly to form the rigid outer protective layer, and any two adjacent rigid outer protective layers are detachably connected by a second connecting assembly 44.

[0008] In the first aspect, the first half protective layer assembly comprises: a first rigid outer protective layer inner wall, a first rigid outer protective layer outer wall, and a first rubber waterstop arranged between the first rigid outer protective layer inner wall and the first rigid outer protective layer outer wall; and / or, the second half protective layer assembly comprises: a second rigid outer protective layer inner wall, a second rigid outer protective layer outer wall, and a second rubber waterstop arranged between the second rigid outer protective layer inner wall and the second rigid outer protective layer outer wall.

[0009] In the first aspect, the meltable excavation body further comprises: a heat-insulating rigid fixing plate with a hollow structure, and the second waterproof heat-insulating layer (32) is arranged in the hollow structure of the heat-insulating rigid fixing plate (6).

[0010] The first aspect of the present application provides a solid-liquid phase change simulation method for multi-step excavation, the simulation method comprising:

[0011] According to the performance parameters of the original rock, a corresponding performance meltable material is configured, and the meltable excavation module is prepared according to the meltable material;

[0012] The meltable excavation module is excavated to simulate the multi-step excavation process;

[0013] The meltable excavation module comprises: a meltable material, a flexible waterproof heat-insulating layer, a rigid outer protective layer, and a waterproof heater corresponding to the number of meltable excavation units; the flexible waterproof heat-insulating layer comprises a first waterproof heat-insulating layer and a second waterproof heat-insulating layer, the first waterproof heat-insulating layer forms a containing space, the meltable material is filled in the containing space, the second waterproof heat-insulating layer is arranged in the meltable material and sequentially divides the meltable excavation module in the transverse direction and the longitudinal direction of the meltable excavation module to form a plurality of independent meltable excavation units; the rigid outer protective layer is arranged at the peripheral part of the first waterproof heat-insulating layer; each waterproof heater is arranged in one meltable excavation unit.

[0014] In the second aspect, the method further comprises:

[0015] The prepared meltable excavation modules are spliced to form a meltable excavation body;

[0016] The meltable excavation body is excavated to simulate the multi-step excavation process of the meltable excavation body composed of a plurality of meltable excavation modules.

[0017] In the second aspect, the meltable material corresponding to the performance is configured according to the performance parameters of the original rock, and the meltable excavation module is prepared according to the meltable material of the meltable excavation body, specifically comprising:

[0018] S1, the bottom of the rigid outer protective layer is sealed, then the first waterproof heat-insulating layer is installed on the inner wall of the rigid outer protective layer by coating lubricating oil on the inner wall of the rigid outer protective layer;

[0019] S2 places the rigid outer protective layer vertically on the ground, places the second waterproof and heat insulation layer into the heat insulation layer rigid fixing piece to form a whole, and places the whole formed by the second waterproof and heat insulation layer and the heat insulation layer rigid fixing piece into a designated position of the rigid outer protective layer, divides the internal space of the rigid outer protective layer to form a plurality of independent meltable excavation mold units, and obtains a first excavation body preparation container;

[0020] S3 obtains the required amount of the meltable material for the tunnel excavation unit by calculating the volume of the tunnel excavation section and the volume change caused by the phase change of the meltable material, pours the meltable material into the first excavation body preparation container according to the calculated required amount, and inserts each waterproof heater into a corresponding meltable excavation mold unit, wherein the waterproof heater is consistent with the length of the meltable excavation mold unit, then removes the heat insulation layer rigid fixing piece, and then performs low-temperature treatment on the meltable material to obtain a first meltable excavation module.

[0021] In the second aspect, the method further comprises:

[0022] In S3, the isolation layer is placed on the side of the first excavation body preparation container before the low-temperature treatment on the meltable material;

[0023] The splicing of the prepared plurality of meltable excavation modules to form a meltable excavation body specifically comprises:

[0024] The S1 and S2 are repeated to obtain a second excavation body preparation container, the isolation layer is located between the first excavation body preparation container and the second excavation body preparation container, and the S3 is repeated to pour the corresponding required amount of meltable material into the second excavation body preparation container, and the low-temperature treatment is performed on the meltable material to obtain a second meltable excavation module;

[0025] The first meltable excavation module and the second meltable excavation module are spliced through a second connecting assembly;

[0026] The S1 and S2 are continuously repeated to increase the number of meltable excavation modules until a meltable excavation body with a required length for model test is finally spliced.

[0027] In the second aspect, the splicing of the prepared plurality of meltable excavation modules to form a meltable excavation body specifically comprises:

[0028] Repeating the S1 and S2 to obtain a second excavation body preparation container, placing an isolation layer between the first excavation body preparation container and the second excavation body preparation container, and repeating the S3 to fill the second excavation body preparation container with a corresponding required amount of fusible material, and performing low-temperature treatment on the fusible material to obtain a second fusible excavation module;

[0029] Splicing the first fusible excavation module and the second fusible excavation module through a second connecting assembly;

[0030] Continuing to repeat the S1 and S2 to increase the number of the fusible excavation modules until a fusible excavation body of a required length for model testing is formed by splicing.

[0031] In the second aspect, the multiple steps are three steps, including an upper step, a middle step, and a lower step; the fusible excavation body is divided into three layers from top to bottom by the upper step, the middle step, and the lower step; the upper step traverses each of the fusible excavation modules; the middle step traverses each of the fusible excavation modules; and the lower step traverses each of the fusible excavation modules.

[0032] The method further includes:

[0033] The multiple fusible excavation units in any one of the fusible excavation modules are numbered according to a, b, c, d, e, f, g, and h;

[0034] During preliminary excavation, the fusible excavation unit numbered a located in the upper step is used as a pilot hole unit, a corresponding waterproof heater is connected to heat and melt the fusible excavation unit numbered a, and two feet are continuously excavated; then a corresponding waterproof heater is connected to heat and melt the fusible excavation unit numbered b in the upper step, and one foot is excavated; and a corresponding waterproof heater is connected to heat and melt the two fusible excavation units numbered c and d in the middle step, and one foot is excavated, completing the preliminary excavation.

[0035] The fusible excavation units numbered a, b, c, and d are heated and melted again, and one foot is excavated.

[0036] A corresponding waterproof heater is connected to heat and melt the fusible excavation unit numbered e in the middle step, the fusible excavation unit numbered f in the lower step, and the fusible excavation unit numbered g in the lower step in order, and one foot is excavated.

[0037] According to the order of the meltable excavation units numbered a, b, c, d, e, f, g, h, continue to excavate, excavate one foot each time until all excavation is completed, connect the corresponding waterproof heater to the meltable excavation unit each time to heat and melt the excavation, and then recycle the meltable material melted into liquid. The meltable excavation module has a length of one foot of excavation.

[0038] Beneficial effects: In the present application, the meltable excavation body can replace the original rock excavation body in the model test of excavation simulation, and the strength and stiffness of the meltable excavation body can be adjusted by adjusting the proportion of the meltable material to simulate the strength and stiffness of the real excavation body, and then simulate the deformation characteristics of the original surrounding rock. Since the meltable material is made of a modified liquid material, such as water, mercury, grease or other liquid materials at room temperature, and other materials are mixed, and after low temperature treatment, phase change occurs, and becomes a solid material with certain strength and stiffness. In the indoor model test, the meltable material in the meltable excavation body can be melted by heating to unload the tunnel surrounding rock, and simulate the tunnel excavation process. The rigid outer protective layer is arranged on the outer part of the first waterproof thermal insulation layer, which can prevent the interference of the heating temperature of the waterproof heater on the meltable excavation body and the liquid formed by the melting of the meltable excavation body on the tunnel surrounding rock during the excavation simulation process. At the same time, the rigid outer protective layer is arranged on the outer part of the first waterproof thermal insulation layer, and the shape and size of the inner wall contour of the rigid outer protective layer are consistent with the size of the tunnel contour of the model test. Since the first waterproof thermal insulation layer is composed of a waterproof flexible insulation material and cannot be shaped, the rigid outer protective layer is composed of a rigid material and can support the first waterproof thermal insulation layer to avoid deformation of the first waterproof thermal insulation layer due to the extrusion of the meltable material. The first waterproof thermal insulation layer and the isolation layer are both composed of a waterproof flexible insulation material, and the meltable material is in a containing space formed by the first waterproof thermal insulation layer and the isolation layer. When the meltable material melts, it is convenient to recycle the meltable material. At the same time, the isolation layer divides the meltable excavation body into multiple segments, which plays a role in separating any two meltable excavation modules, so that the excavation process of the excavation body achieves the purpose of segmented excavation without interference between segments. The second waterproof thermal insulation layer divides the meltable excavation module into multiple independent meltable excavation units, and each waterproof heater is arranged in a meltable excavation unit. During the excavation simulation process, the waterproof heater can flexibly and orderly heat the corresponding meltable excavation unit to meet the excavation of different tunnels and make the excavation more flexible. The waterproof heater not only melts the meltable material by heating the corresponding meltable excavation unit to achieve the purpose of excavation, but also avoids damage to the waterproof heater by the meltable material. The waterproof heater is made of high-temperature-resistant and high-strength sealing materials, such as high-temperature-resistant tempered glass, and has a heating coil inside to perform electric power heating. The melting speed of the meltable material can be controlled by controlling the heating power to control the excavation rate of the meltable excavation unit. At the same time, after the melting is completed, the waterproof heater and the meltable material can be recycled and used, which reduces the test cost. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present specification or the prior art, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some of the embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0040] Fig. 1 is a schematic diagram of the cross-sectional structure of the excavated body provided by the present application;

[0041] Fig. 2 is a schematic diagram of the longitudinal cross-sectional structure of the excavated body provided by the present application;

[0042] Fig. 3 is a schematic diagram of the three-dimensional structure of the excavated body spliced by the three-section excavated modules provided by the present application.

[0043] Explanation of reference signs:

[0044] 1, isolation layer; 2, fusible material; 3, flexible waterproof and heat insulation layer; 31, first waterproof and heat insulation layer; 32, second waterproof and heat insulation layer; 4, rigid outer protective layer; 41, first half protective layer assembly; 411, first rigid outer protective layer inner wall; 412, first rigid outer protective layer inner wall; 413, first rubber waterstop; 42, second half protective layer assembly; 421, second rigid outer protective layer inner wall; 422, second rigid outer protective layer inner wall; 423, second rubber waterstop; 43, first connecting assembly; 44, second connecting assembly; 5, waterproof heater; 6, heat insulation layer rigid fixing plate. DETAILED DESCRIPTION

[0045] The technical solutions in the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art belong to the scope of protection of the present application.

[0046] Meanwhile, throughout the specification, unless otherwise specifically stated, the terms used herein should be understood as having the meanings commonly used in the art. Therefore, unless otherwise defined, all technical and scientific terms used herein have the same meanings as generally understood by those skilled in the art to which the present application belongs. If there is a contradiction, the present specification takes precedence.

[0047] Example 1

[0048] As Figs. 1-3As shown, the embodiment 1 provides a meltable excavation body, a meltable excavation body, the meltable excavation body comprises: a plurality of meltable excavation modules and a plurality of isolation layers 1, any two meltable excavation modules are adjacent spliced through an isolation layer 1 to form the meltable excavation body, each of the meltable excavation modules comprises: a meltable material 2, a flexible waterproof thermal insulation layer 3, a rigid outer protective layer 4 and a waterproof heater 5 matched with the number of the meltable excavation units; wherein the flexible waterproof thermal insulation layer 3 comprises a first waterproof thermal insulation layer 31 and a second waterproof thermal insulation layer 32, the first waterproof thermal insulation layer 31 and the isolation layers 1 on the corresponding two sides of the meltable excavation module enclose a containing space, the meltable material 2 is filled in the containing space, the second waterproof thermal insulation layer 32 is arranged in the meltable material 2 and sequentially divides the meltable excavation module in the transverse direction and the longitudinal direction of the meltable excavation module to form a plurality of independent meltable excavation units; the rigid outer protective layer 4 is arranged on the peripheral part of the first waterproof thermal insulation layer 31; each of the waterproof heaters 5 is correspondingly arranged in one of the meltable excavation units.

[0049] In the present application, the meltable excavation body can replace the original rock excavation body in the model test of excavation simulation, and the strength and rigidity of the meltable excavation body can be adjusted by adjusting the proportion of the meltable material to simulate the strength and rigidity of the real excavation body, and then simulate the deformation characteristics of the original surrounding rock. Since the meltable material is made of a modified liquid material, such as water, mercury, grease or other liquid materials at room temperature mixed with other materials, after low-temperature treatment, it changes into a solid material with certain strength and rigidity. In the indoor model test, the meltable material in the meltable excavation body can be melted by heating to unload the tunnel surrounding rock and simulate the tunnel excavation process. The rigid outer protective layer is arranged on the outer peripheral part of the first waterproof thermal insulation layer to prevent the interference of the temperature of the waterproof heater heating the meltable excavation body and the liquid formed by the melting of the meltable excavation body on the tunnel surrounding rock during the excavation simulation process. At the same time, the rigid outer protective layer is arranged on the outer peripheral part of the first waterproof thermal insulation layer, and the shape and size of the inner wall contour of the rigid outer protective layer are consistent with the size of the tunnel contour of the model test. Since the first waterproof thermal insulation layer is composed of a waterproof flexible insulation material and cannot be shaped, the rigid outer protective layer is composed of a rigid material and can support the first waterproof thermal insulation layer to prevent the deformation of the first waterproof thermal insulation layer caused by the extrusion of the meltable material. The first waterproof thermal insulation layer and the isolation layer are both composed of a waterproof flexible insulation material, and the meltable material is in a containing space formed by the first waterproof thermal insulation layer and the isolation layer. When the meltable material melts, it is convenient to recycle the meltable material. At the same time, the isolation layer divides the meltable excavation body into multiple segments between any two meltable excavation modules, plays a role in separating any two meltable excavation modules, and achieves the purpose of segmented excavation and mutual non-interference between segments in the process of excavating the excavation body. The second waterproof thermal insulation layer divides the meltable excavation module into multiple independent meltable excavation units, and each waterproof heater is arranged in a corresponding meltable excavation unit. During the excavation simulation process, the waterproof heater can flexibly and orderly heat the corresponding meltable excavation unit to meet the excavation of different tunnels and make the excavation more flexible. The waterproof heater not only melts the meltable material by heating the corresponding meltable excavation unit to achieve the purpose of excavation, but also avoids damage to the waterproof heater by the meltable material. The waterproof heater is made of high-temperature-resistant and high-strength airtight material, such as high-temperature-resistant tempered glass, and has a heating coil inside to perform electric power heating. The melting speed of the meltable material can be controlled by controlling the heating power to control the excavation rate of the meltable excavation unit. At the same time, after the melting is completed, the waterproof heater and the meltable material can be recycled and used, reducing the test cost.

[0050] In some possible embodiments, the rigid outer protective layer 4 comprises: a first half protective layer assembly 41 and a second half protective layer assembly 42, the first half protective layer assembly 41 and the second half protective layer assembly 42 are detachably connected by a first connecting assembly 43 to enclose the rigid outer protective layer 4, and any two adjacent rigid outer protective layers 4 are detachably connected by a second connecting assembly 44; the first half protective layer assembly 41 comprises: a first rigid outer protective layer inner wall 411, a first rigid outer protective layer outer wall 412, and a first rubber waterstop 413 arranged between the first rigid outer protective layer inner wall 411 and the first rigid outer protective layer outer wall 412; and / or, the second half protective layer assembly 42 comprises: a second rigid outer protective layer inner wall 421, a second rigid outer protective layer outer wall 422, and a second rubber waterstop 423 arranged between the second rigid outer protective layer inner wall 421 and the second rigid outer protective layer outer wall 422; and the meltable excavation body further comprises: a heat-insulating rigid fixing plate 6, which is internally hollow, and the second waterproof heat-insulating layer 32 is arranged in the hollow structure of the heat-insulating rigid fixing plate 6.

[0051] Specifically, the rigid outer protective layer is a separable splicing cylindrical structure made of rigid material, the first half protective layer assembly and the second half protective layer assembly are detachably connected by the first connecting assembly, which facilitates the installation and disassembly of the rigid outer protective layer, and meanwhile, the second connecting assembly is used to detachably connect any two adjacent rigid outer protective layers, which helps to adjust the number of rigid outer protective layers, the number of meltable excavation modules, and thus the length of the meltable excavation body, so as to obtain a meltable excavation body with a desired length.

[0052] Embodiment two

[0053] As Figs. 1-3As shown, the second embodiment of the present application provides a solid-liquid phase change simulation method for multi-step excavation, which comprises: preparing a meltable excavation module, which comprises: configuring a meltable material with corresponding performance according to the performance parameters of the original rock, and preparing the meltable excavation module according to the meltable material; excavating the meltable excavation module to simulate the multi-step excavation process; wherein the meltable excavation module comprises: a meltable material, a flexible waterproof thermal insulation layer, a rigid outer protective layer, and a waterproof heater compatible with the number of meltable excavation units; wherein the flexible waterproof thermal insulation layer comprises a first waterproof thermal insulation layer and a second waterproof thermal insulation layer, the first waterproof thermal insulation layer forms a containing space, the meltable material is filled in the containing space, and the second waterproof thermal insulation layer is arranged in the meltable material and is sequentially divided in the transverse direction and the longitudinal direction of the meltable excavation module to form a plurality of independent meltable excavation units; the rigid outer protective layer is arranged at the peripheral part of the first waterproof thermal insulation layer; and each waterproof heating is correspondingly arranged in one meltable excavation unit.

[0054] In the present application, the meltable material is the main material of the meltable excavation body, which is made of a modified liquid material, such as water, mercury, grease or other liquid materials at room temperature mixed with other materials, which is changed into a solid material with certain strength and rigidity after low-temperature treatment. The meltable material with corresponding performance is configured according to the strength and rigidity of the original rock, so as to simulate the strength and rigidity of the original surrounding rock, replace the surrounding rock in situ, simulate the deformation characteristics of the original surrounding rock, and make the simulation result more realistic. It should be noted that the meltable excavation body in the second embodiment is the same as the meltable excavation body in the first embodiment, and therefore the other performance principles of the meltable excavation body are not repeated here, and the unexplained part can be referred to the first embodiment.

[0055] In some possible embodiments, the method further comprises: splicing the prepared several meltable excavation modules to form a meltable excavation body; and excavating the meltable excavation body to simulate the multi-step excavation process of the meltable excavation body composed of the plurality of meltable excavation modules.

[0056] Specifically, the plurality of meltable excavation modules are spliced to obtain a meltable excavation body, and an isolation layer is arranged between any two meltable excavation modules, which plays an isolating role between any two meltable excavation modules, divides the meltable excavation body into multiple sections, and plays a role of realizing segmented excavation of the meltable excavation body without interference between the sections during the excavation of the meltable excavation body.

[0057] In some possible embodiments, the configuration of the corresponding performance of the meltable material according to the performance parameters of the original rock, and the preparation of the meltable excavation module according to the meltable excavation body material specifically comprises: S1, water sealing is performed on the bottom of the rigid outer protective layer, then lubricating oil is coated on the inner wall of the rigid outer protective layer, and the first waterproof thermal insulation layer is installed against the inner wall of the rigid outer protective layer; S2, the rigid outer protective layer is placed upright on the ground, the second waterproof thermal insulation layer is placed into the thermal insulation layer rigid fixing piece to form an integral whole, the integral whole formed by the second waterproof thermal insulation layer and the thermal insulation layer rigid fixing piece is placed into a specified position of the rigid outer protective layer, the internal space of the rigid outer protective layer is divided to form a plurality of independent meltable excavation mold units, and a first excavation body preparation container is obtained; S3, the amount of the meltable material required by the tunnel excavation unit is obtained by calculating the volume of the tunnel excavation section and the volume change caused by the phase change of the meltable material, the meltable material is poured into the first excavation body preparation container according to the calculated required amount, and each waterproof heater is inserted into a corresponding meltable excavation mold unit, the waterproof heater is consistent with the length of the meltable excavation mold unit, then the thermal insulation layer rigid fixing piece is pulled out, and then the meltable material is subjected to low-temperature treatment to obtain a first meltable excavation module.

[0058] Specifically, the rigid outer protective layer serves as the main structure in the process of preparing the meltable excavation module, the shape and size of the inner wall profile of the rigid outer protective layer are consistent with the size of the tunnel profile in the model test, and the rigid outer protective layer plays the role of a mold frame. The lubricating oil is coated on the wall of the rigid outer protective layer, and the first waterproof thermal insulation layer is installed against the inner wall of the rigid outer protective layer, which facilitates demolding of the meltable excavation module in the later stage. The second waterproof thermal insulation layer is composed of waterproof flexible thermal insulation material and has poor shaping effect, and the thermal insulation layer rigid fixing piece is made of rigid material and can fix the second waterproof thermal insulation layer. Therefore, in the process of preparing the meltable excavation module, the liquid meltable material is poured in, and the thermal insulation layer rigid fixing piece can play a role in stabilizing the second waterproof thermal insulation layer, so as to avoid deformation of the second waterproof thermal insulation layer caused by extrusion of the liquid. At the same time, the thermal insulation layer fixing piece is removed when the liquid meltable material is subjected to low-temperature phase change treatment, so as to avoid affecting the final overall strength of the excavation body. At the same time, the internal space of the rigid outer protective layer is divided to form a plurality of independent meltable excavation mold units, so that, after the meltable material is poured in, the meltable excavation module obtained has the second waterproof thermal insulation layer, which divides the meltable excavation module into a plurality of independent meltable excavation units, facilitating flexible and orderly excavation of the meltable excavation body in the subsequent stage. At the same time, before the meltable excavation body is prepared, an independent excavation body unit is prepared first, sampling test is performed, and whether the strength and rigidity of the independent excavation body unit meet the requirements of the original rock is verified. If yes, the excavation body is prepared; if not, the meltable material is prepared again.

[0059] In some possible implementation manners, the method further comprises: before the low-temperature treatment of the fusible material in S3, placing the isolation layer in the side of the first excavation body preparation container; the splicing of the prepared plurality of fusible excavation modules to form the fusible excavation body specifically comprises: repeating S1 and S2 to obtain a second excavation body preparation container, the isolation layer is placed between the first excavation body preparation container and the second excavation body preparation container, and S3 is repeated to pour the corresponding required amount of fusible material into the second excavation body preparation container, the low-temperature treatment of the fusible material is performed to obtain a second fusible excavation module; the first fusible excavation module and the second fusible excavation module are spliced through a second connecting assembly; S1 and S2 are continuously repeated to increase the number of the fusible excavation modules, until the fusible excavation body of the required length for the model test is finally spliced.

[0060] Specifically, the plurality of fusible excavation modules are spliced to obtain the fusible excavation body, the fusible excavation body of the required length of the excavation tunnel can be obtained by increasing or decreasing the number of the fusible excavation modules, and the isolation layer is arranged between any two fusible excavation modules to segment the fusible excavation body, thereby facilitating the segmented excavation of the fusible excavation body.

[0061] In some possible implementation manners, the splicing of the prepared plurality of fusible excavation modules to form the fusible excavation body specifically comprises: repeating S1 and S2 to obtain a second excavation body preparation container, the isolation layer is placed between the first excavation body preparation container and the second excavation body preparation container, and S3 is repeated to pour the corresponding required amount of fusible material into the second excavation body preparation container, the low-temperature treatment of the fusible material is performed to obtain a second fusible excavation module; the first fusible excavation module and the second fusible excavation module are spliced through a second connecting assembly; S1 and S2 are continuously repeated to increase the number of the fusible excavation modules, until the fusible excavation body of the required length for the model test is finally spliced.

[0062] Specifically, the plurality of fusible excavation modules are spliced to obtain the fusible excavation body, the fusible excavation body of the required length of the excavation tunnel can be obtained by increasing or decreasing the number of the fusible excavation modules, and the isolation layer is arranged between any two fusible excavation modules to segment the fusible excavation body, thereby facilitating the segmented excavation of the fusible excavation body.

[0063] In some possible implementation manners, the multiple steps are three steps, and the three steps include an upper step, a middle step and a lower step; the meltable excavation body is divided into three layers from top to bottom by the upper step, the middle step and the lower step, the upper step is transverse to each of the meltable excavation modules, the middle step is transverse to each of the meltable excavation modules, and the lower step is transverse to each of the meltable excavation modules; the method further includes: numbering the multiple meltable excavation units in any one of the meltable excavation modules according to a, b, c, d, e, f, g and h; in preliminary excavation, the meltable excavation unit numbered a on the upper step is taken as a pilot pit unit, a corresponding waterproof heater is connected to the meltable excavation unit numbered a to heat and melt the meltable excavation unit numbered a, and two feet are continuously excavated; then a corresponding waterproof heater is connected to the meltable excavation unit numbered b on the upper step to heat and melt the meltable excavation unit numbered b, one foot is excavated; and a corresponding waterproof heater is connected to the two meltable excavation units numbered c and d on the middle step to heat and melt the two meltable excavation units, one foot is excavated, and preliminary excavation is completed; the meltable excavation units numbered a, b, c and d are heated and melted again, one foot is excavated; a corresponding waterproof heater is connected to the meltable excavation unit numbered e on the middle step, the meltable excavation unit numbered f on the lower step and the meltable excavation unit numbered g on the lower step in sequence to heat and melt the three meltable excavation units, one foot is excavated; excavation is continuously performed in the order of the meltable excavation units numbered a, b, c, d, e, f, g and h, one foot is excavated each time, until all excavation is completed; after the meltable excavation unit is heated and melted by the corresponding waterproof heater each time, the meltable material heated and melted into liquid is recycled, and the meltable excavation module has a length of one foot of excavation.

[0064] Specifically, the meltable excavation body has similar strength and stiffness to the original rock simulation of excavation, can better restore the actual excavation conditions, and get rid of the shape restriction of the tunnel, while reducing the excavation disturbance, more intuitively showing the change rule of the surrounding rock caused by tunnel excavation. The prepared meltable excavation body is placed in the tunnel prepared in advance in the test model before excavation, the model is stressed to simulate the stress environment of the tunnel, and the real environment simulation effect can be achieved. The meltable excavation unit is heated and melted by the waterproof heater to implement excavation, which is more efficient for tunnel excavation simulation, and can also reduce the disturbance to the tunnel model, and show the influence of the stress change caused by the excavation process on the surrounding rock of the tunnel. At the same time, the use of the meltable excavation body for tunnel excavation simulation can get rid of the shape restriction of the tunnel and be applied to tunnels with irregular cross sections, and more intuitively show the change rule of the surrounding rock of the tunnel. Since the meltable excavation body can be heated and melted by the waterproof heater, it can simulate various tunnel excavation methods, and the operation of the excavation simulation is simple. The power of the waterproof heater can be adjusted to control the excavation speed, and the isolation layer is divided into multiple sections, which can realize segmented excavation at the same time without interference between sections. Specifically, compared with the traditional manual excavation, the solid-liquid phase change physical simulation method for irregular cross section multi-step excavation of embodiment three is more efficient for tunnel excavation simulation using the meltable excavation body, and can also reduce the disturbance to the tunnel model and show the influence of the stress change caused by the excavation on the surrounding rock of the tunnel. At the same time, compared with mechanical excavation, the use of the meltable excavation body for tunnel excavation simulation can get rid of the shape restriction of the tunnel and be applied to tunnels with irregular cross sections, and more intuitively show the change rule of the surrounding rock of the tunnel. Moreover, the use of the meltable excavation body for tunnel excavation simulation can simulate various tunnel excavation methods and realize segmented excavation without interference between sections. In addition, the strength and stiffness of the meltable excavation body can be adjusted, and the strength and stiffness of the original surrounding rock can be simulated by adjusting the ratio of the meltable material 1, which can well replace the original surrounding rock in situ, simulate the deformation characteristics of the original surrounding rock, and the results are more realistic. The meltable material 1 is easy to obtain and the operation of the excavation simulation is simple, and the meltable material 1 and the waterproof heater 5 can be recycled, which can reduce the cost of excavation test. It should be noted that this embodiment three uses the meltable excavation body described in embodiments one and two to replace the original rock excavation body for multi-step excavation simulation, so the performance principle of the meltable excavation body is not repeated here, and the parts not described in detail can be referred to embodiment one.

[0065] The preferred embodiments of the present application are described in detail above. It should be understood that those skilled in the art can make many modifications and changes without creative labor based on the concept of the present application. Therefore, any technical solutions obtained by logical analysis, reasoning or limited experiments based on the prior art within the concept of the present application shall be within the protection scope determined by the claims.

Claims

1. A fusible excavator, characterized in that, The fusible excavator includes: The system comprises several fusible excavation modules and several isolation layers (1). Any two fusible excavation modules are joined together adjacently through an isolation layer (1) to form the fusible excavation body. Each fusible excavation module includes: a fusible material (2), a flexible waterproof and heat-insulating layer (3), a rigid outer protective layer (4), and a waterproof heater (5) adapted to the number of fusible excavation units. The flexible waterproof and heat-insulating layer (3) includes a first waterproof and heat-insulating layer (31) and a second waterproof and heat-insulating layer (32). The first waterproof and heat-insulating layer (31) is connected to the fusible excavation unit. The isolation layers (1) on both sides of the module enclose a space to form an accommodating space. The fusible material (2) is filled in the accommodating space. The second waterproof and heat-insulating layer (32) is arranged in the fusible material (2) and is divided into multiple independent fusible excavation units in the transverse and longitudinal directions of the fusible excavation module. The rigid outer protective layer (4) is covered on the outer periphery of the first waterproof and heat-insulating layer (31). Each waterproof heater (5) is correspondingly arranged in one of the fusible excavation units. The rigid outer protective layer (4) includes: a first half-protective layer assembly (41) and a second half-protective layer assembly (42), the first half-protective layer assembly (41) and the second half-protective layer assembly (42) are detachably connected by a first connecting assembly (43) to enclose and form the rigid outer protective layer (4), and any two adjacent rigid outer protective layers (4) are detachably connected by a second connecting assembly (44).

2. The fusible excavator body as described in claim 1, characterized in that: The first semi-protective layer assembly (41) includes: a first rigid outer protective layer inner wall (411), a first rigid outer protective layer outer wall (412), and a first rubber waterstop strip (413) attached between the first rigid outer protective layer inner wall (411) and the first rigid outer protective layer outer wall (412). And / or, The second semi-protective layer assembly (42) includes: a second rigid outer protective layer inner wall (421), a second rigid outer protective layer outer wall (422), and a second rubber waterstop strip (423) that is attached between the second rigid outer protective layer inner wall (421) and the second rigid outer protective layer outer wall (422).

3. The fusible excavator body as described in claim 2, characterized in that, Also includes: The heat-insulating rigid fixing sheet has a hollow internal structure, and the second waterproof heat-insulating layer (32) is disposed inside the hollow structure of the heat-insulating rigid fixing sheet (6).

4. A solid-liquid phase transition simulation method for multi-stage excavation, used for the fusible excavation body as described in claim 1, characterized in that, The simulation method includes: The preparation of a fusible excavation module includes: configuring a fusible material with corresponding properties based on the performance parameters of the original rock, and preparing the fusible excavation module based on the fusible material; The fusible excavation module is used to excavate in order to simulate a multi-stage excavation process; The fusible excavation module includes: a fusible material, a flexible waterproof and heat-insulating layer, a rigid outer protective layer, and waterproof heaters adapted to the number of fusible excavation units. The flexible waterproof and heat-insulating layer includes a first waterproof and heat-insulating layer and a second waterproof and heat-insulating layer. The first waterproof and heat-insulating layer forms an accommodating space, which is filled with the fusible material. The second waterproof and heat-insulating layer is arranged within the fusible material and sequentially divides the fusible excavation module in both the transverse and longitudinal directions to form multiple independent fusible excavation units. The rigid outer protective layer covers the outer periphery of the first waterproof and heat-insulating layer. Each waterproof heater is correspondingly disposed in one of the fusible excavation units.

5. The solid-liquid phase transition simulation method for multi-stage excavation as described in claim 4, characterized in that, The method further includes: The prepared fusible excavation modules are spliced ​​together to form a fusible excavation body; The fusible excavation body is excavated to simulate the multi-stage excavation process of a fusible excavation body composed of multiple fusible excavation modules.

6. The solid-liquid phase transition simulation method for multi-stage excavation as described in claim 5, characterized in that, The process of configuring a fusible material with corresponding properties based on the performance parameters of the original rock, and preparing the fusible excavation module based on the fusible material specifically includes: S1 performs a water-stop seal on the bottom of the rigid outer protective layer, then applies lubricating oil to the inner wall of the rigid outer protective layer and installs the first waterproof and heat-insulating layer against the inner wall of the rigid outer protective layer. S2. The rigid outer protective layer is placed upright on the ground. The second waterproof and heat-insulating layer is placed into the heat-insulating rigid fixing piece to form a whole. The whole formed by the second waterproof and heat-insulating layer and the heat-insulating rigid fixing piece is placed in the designated position of the rigid outer protective layer. The internal space of the rigid outer protective layer is divided into multiple independent fusible excavation mold units to obtain the first excavation body preparation container. S3 calculates the volume of the tunnel excavation section and the volume change caused by the phase change of the fusible material to obtain the amount of fusible material required for the tunnel excavation unit. The fusible material is poured into the first excavation body preparation container according to the calculated amount, and each of the waterproof heaters is inserted into a corresponding fusible excavation mold unit. The length of the waterproof heater is the same as that of the fusible excavation mold unit. Then the heat insulation rigid fixing plate is removed, and the fusible material is subjected to low temperature treatment to obtain the first fusible excavation module.

7. The solid-liquid phase transition simulation method for multi-stage excavation as described in claim 6, characterized in that, The method further includes: In step S3, before the fusible material is cryogenically treated, the isolation layer is placed on the side of the container for preparing the first excavation body. The step of splicing together the prepared plurality of fusible excavation modules to form a fusible excavation body specifically includes: Repeat steps S1 and S2 to obtain a second excavation body preparation container, wherein the isolation layer is located between the first excavation body preparation container and the second excavation body preparation container, and repeat step S3 to fill the second excavation body preparation container with the required amount of fusible material, and perform low-temperature treatment on the fusible material to obtain a second fusible excavation module. The first fusible excavation module and the second fusible excavation module are spliced ​​together using the second connecting component; Continue repeating S1 and S2, increasing the number of the fusible excavation modules, until they are finally assembled to form a fusible excavation body of the required length for the model test.

8. The solid-liquid phase transition simulation method for multi-stage excavation as described in claim 7, characterized in that, The step of splicing together the prepared plurality of fusible excavation modules to form a fusible excavation body specifically includes: Repeat steps S1 and S2 to obtain a second excavation body preparation container. Place an isolation layer between the first and second excavation body preparation containers. Repeat step S3 to fill the second excavation body preparation container with the required amount of fusible material. Perform low-temperature treatment on the fusible material to obtain a second fusible excavation module. The first fusible excavation module and the second fusible excavation module are spliced ​​together using the second connecting component; Continue repeating S1 and S2, increasing the number of the fusible excavation modules, until they are finally assembled to form a fusible excavation body of the required length for the model test.

9. A solid-liquid phase transition simulation method for multi-stage excavation as described in any one of claims 7 or 8, characterized in that: The multi-step structure consists of three steps, including an upper step, a middle step, and a lower step. The fusible excavation body is divided into three layers from top to bottom by the upper step, the middle step, and the lower step. The upper step traverses each of the fusible excavation modules, the middle step traverses each of the fusible excavation modules, and the lower step traverses each of the fusible excavation modules. The method further includes: The multiple fusible excavation units in any one of the fusible excavation modules are numbered according to a, b, c, d, e, f, g, h; During the initial excavation, the fusible excavation unit numbered 'a' on the upper bench is used as a pilot unit. A corresponding waterproof heater is connected to the fusible excavation unit numbered 'a' to heat and melt it, and two advances are made consecutively. Then, the corresponding waterproof heater is connected to the fusible excavation unit numbered 'b' on the upper bench to heat and melt it, and one advance is made. Finally, the corresponding waterproof heaters are connected to the two fusible excavation units numbered 'c' and 'd' on the middle bench to heat and melt them, and one advance is made, thus completing the initial excavation. The fusible excavation units numbered a, b, c, and d are heated and melted a second time to excavate one advance. Connect the corresponding waterproof heaters to heat and melt the fusible excavation unit with the central step number e, the fusible excavation unit with the lower step number f, and the fusible excavation unit with the lower step number g in sequence, and excavate one advance. Excavation continues in the order of the fusible excavation units numbered a, b, c, d, e, f, g, h, with one excavation advance per unit until all excavation is completed. After each excavation, the corresponding waterproof heater is connected to heat and melt the fusible excavation unit, and the fusible material that has been heated and melted into liquid is recycled. The length of the fusible excavation module is one excavation advance.

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