Construction method of waterproof ceramic layer based on open-cut fabricated tunnel and tunnel construction equipment

Abstract

The invention provides a construction method of a waterproof ceramic layer based on an open-cut fabricated tunnel and tunnel construction equipment, and particularly relates to the technical field of open-cut tunnel construction, in the construction method of the waterproof ceramic layer based on the open-cut fabricated tunnel, when a foundation pit is excavated, earthwork is directly split and crushed, and an earth-rock mixture is obtained. And then screening the soil-rock mixture to separate aggregate and coarse clay particles. And then the aggregate is manufactured into tunnel structural parts on site, and the tunnel structure is formed through assembling. Meanwhile, the coarse clay particles are made into waterproof ceramic paint, and a waterproof ceramic coating is formed on the surface of the tunnel structure. In this way, the earthwork is directly processed into the tunnel structural part and the waterproof ceramic coating on the site, the waterproof ceramic coating on the surface of the tunnel structure is directly formed, on one hand, the problems of low construction efficiency and overlong construction period caused by earthwork transportation and treatment are avoided, on the other hand, the earthwork can be fully utilized, and the purposes of reducing cost and improving efficiency are achieved.

Description

Technical Field

[0001] This application relates to the technical field of open-cut tunnel construction. Specifically, it relates to a construction method for a waterproof ceramic layer based on an open-cut prefabricated tunnel and tunnel construction equipment. Background Art

[0002] Currently, significant progress has been made in the technology of open-cut prefabricated tunnels. Multiple open-cut prefabricated tunnel projects have been successfully implemented. The successful implementation of these projects not only verifies the feasibility and superiority of the open-cut prefabricated tunnel technology but also provides valuable experience and reference for subsequent similar projects.

[0003] In current open-cut tunnel construction, after excavating the foundation pit, the structure at the top of the tunnel is formed first, and then backfilling is carried out followed by secondary tunnel construction. During the construction process, the excavated soil needs to be transported and stacked to reduce the land occupation at the construction site. When it comes to prefabricated tunnel construction, waterproof treatment is also required, and the construction time of the tunnel is relatively long. As a result, the time and space occupation ratio of soil transportation and stacking are extremely large, seriously affecting the construction efficiency and leading to an extended construction period.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of this application. Therefore, it may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Invention

[0005] The purpose of this application is to overcome the above-mentioned deficiencies of the prior art and provide a construction method for a waterproof ceramic layer based on an open-cut prefabricated tunnel and tunnel construction equipment to solve the problems of low construction efficiency and excessive construction period caused by soil transportation and treatment in open-cut tunnels in the prior art.

[0006] According to one aspect of this application, a construction method for a waterproof ceramic layer based on an open-cut prefabricated tunnel includes the following steps: Excavate the foundation pit, split and crush the soil to obtain a mixture of soil and rock. Screen the mixture of soil and rock to separate out the aggregate and coarse clay particles. Use the aggregate to fabricate and assemble tunnel structural members on-site to form a tunnel structure. Use the coarse clay particles to make a waterproof ceramic coating and form a waterproof ceramic layer on the surface of the tunnel structure.

[0007] According to some embodiments of this application, screening the mixture of soil and rock to separate out the aggregate and coarse clay particles includes the following steps: Crush the mixture of soil and rock and control its moisture content between 8% and 12%.

[0008] According to some embodiments of this application, screening the mixture of soil and rock includes the following steps: Sieve the soil-rock mixture with a sieve having a pore size of 5 mm to 10 mm to obtain a preliminarily sieved mixture; Sieve the preliminarily sieved mixture with a sieve having a pore size of 200 μm to 400 μm to separate out the aggregate and the secondarily sieved mixture; Sieve the secondarily sieved mixture with a sieve having a pore size of 100 μm to 180 μm to separate out the coarse clay particles.

[0009] According to some embodiments of the present application, making a waterproof ceramic coating with the coarse clay particles includes the following steps: Grind the coarse clay particles to obtain coarse clay particles with a particle size of 20 μm to 40 μm; Adjust the viscosity of the coarse clay particles to 3000 mPa·s to 8000 mPa·s.

[0010] According to some embodiments of the present application, adjusting the viscosity of the coarse clay particles to 3000 mPa·s to 8000 mPa·s includes the following steps: Add an antifoaming agent, a dispersant, a thickening agent, and a functional filler to the coarse clay particles. The functional filler at least includes a pH regulator and a preservative, and grind for at least 90 min to form a preliminary slurry; Add a film-forming agent and a leveling agent to the preliminary slurry, and continue to grind for at least 20 min to form a mixed slurry.

[0011] According to some embodiments of the present application, after forming the mixed slurry, the following steps are further included: Filter the mixed slurry with a filter screen having a pore size of 25 μm to 50 μm.

[0012] According to some embodiments of the present application, after forming the mixed slurry, the following steps are further included: Press and mold the mixed slurry to obtain a sheet-shaped ceramic green body; Directly radiatively heat the sheet-shaped ceramic green body by an ultrafast high-temperature sintering process to obtain a cured ceramic green body; Grind the cured ceramic green body for at least 90 min until the particle size of the cured ceramic green body is between 20 μm and 40 μm, and add a coating auxiliary agent to form a waterproof ceramic coating.

[0013] According to some embodiments of the present application, the coating auxiliary agent at least includes a wetting agent, an antibacterial agent, a flame retardant, and a coupling agent.

[0014] According to some embodiments of the present application, before the foundation pit excavation, the following steps are further included: Extract the foundation pit soil at the construction site; Monitor the soil type, water content, plasticity index, and impurity content of the foundation pit soil; According to the soil type, moisture content, plastic index, impurity content, the mixing ratio of the waterproof ceramic coating preparation materials, as well as the coating layer area and thickness of the foundation pit, calculate the amount of soil-rock mixture, the amount of auxiliary solvent, and the amount of functional filler. The proportion of the soil-rock mixture is between 40% and 60%, the proportion of the auxiliary solvent is between 25% and 45%, and the proportion of the functional filler is between 10% and 15%.

[0015] According to one aspect of the present application, there is provided a tunnel construction equipment, which is applied to the implementation of the construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel as described above. The tunnel construction equipment includes: A mixing component, the mixing component includes a mixing tank, and the waterproof ceramic coating is stored in the mixing tank; A spraying component, which is communicated with the mixing tank, and includes a driving structure and a spraying output end; A control component, which is electrically connected to the mixing component and the spraying component, so as to drive the driving structure to drive the spraying output end to form a waterproof ceramic coating on the surface of the tunnel structural member.

[0016] The present application provides a construction method and equipment for a waterproof ceramic layer based on an open-cut prefabricated tunnel. In the construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel, when excavating the foundation pit, directly split and crush the soil to obtain a soil-rock mixture. Then screen the soil-rock mixture to separate the aggregate and coarse clay particles. Subsequently, the aggregate is made into tunnel structural members on site and assembled to form a tunnel structure. At the same time, the coarse clay particles are made into a waterproof ceramic coating to form a waterproof ceramic coating on the surface of the tunnel structure.

[0017] In this way, the soil is directly processed into tunnel structural members and a waterproof ceramic coating on site, and a waterproof ceramic coating on the surface of the tunnel structure is directly formed. On the one hand, it avoids the problems of low construction efficiency and too long construction period caused by soil transportation and treatment. On the other hand, it can also make full use of the soil to achieve the purpose of cost reduction and efficiency improvement.

[0018] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0020] Figure 1Shows a schematic flow chart of a construction method of a waterproof ceramic layer based on an open-cut prefabricated tunnel provided by an embodiment of the present application.

[0021] Figure 2 Shows a schematic flow chart of screening earth-rock mixture in a waterproof ceramic layer based on an open-cut prefabricated tunnel provided by an embodiment of the present application.

[0022] Figure 3 Shows a schematic flow chart of making a waterproof ceramic coating with coarse clay particles in a waterproof ceramic layer based on an open-cut prefabricated tunnel provided by an embodiment of the present application.

[0023] Figure 4 Shows a schematic flow chart of adjusting the viscosity of coarse clay particles in a waterproof ceramic coating made with coarse clay particles in a waterproof ceramic layer based on an open-cut prefabricated tunnel provided by an embodiment of the present application.

[0024] Figure 5 Shows a schematic structural diagram of open-cut prefabricated tunnel construction provided by an embodiment of the present application.

[0025] Figure 6 Shows a three-dimensional structural diagram of a screening assembly of a tunnel construction equipment provided by an embodiment of the present application.

[0026] Figure 7 Shows a three-dimensional structural diagram of a crushing assembly of a tunnel construction equipment provided by an embodiment of the present application.

[0027] Figure 8 Shows a top view of a crushing assembly of a tunnel construction equipment provided by an embodiment of the present application.

[0028] Figure 9 Shows a three-dimensional structural diagram of a spraying assembly of a tunnel construction equipment provided by an embodiment of the present application.

[0029] Figure 10 Shows a three-dimensional structural diagram of a mixing assembly of a tunnel construction equipment provided by an embodiment of the present application.

[0030] The above-mentioned drawings include the following reference numerals: 10. Foundation pit; 20. Mixing component; 21. Mixing tank; 22. Head; 23. Flange discharge port; 24. Saddle; 25. Support seat; 26. Production staircase; 30. Spraying component; 31. Driving structure; 311. Base; 312. Rotary support; 313. Feed inlet; 314. Shoulder joint; 315. Upper arm; 316. Elbow joint; 317. Forearm; 318. Wrist joint; 32. Spraying output end; 40. Screening component; 41. Screening machine body; 42. Sieve device bin; 43. Screening motor; 44. Control console; 45. Sand and gravel discharge port; 46. Soil particle discharge port; 47. Rotating shaft; 48. Drum; 50. Crushing component; 51. Feed hopper; 52. Crushing motor; 53. Crusher frame; 54. Roller teeth; 55. Crushing chamber; 56. Crusher discharge port; 60. Tunnel structural member. Detailed implementation manners

[0031] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the scope of protection of the present application.

[0032] The following disclosure provides many different embodiments or examples for implementing different structures of the present application. To simplify the disclosure of the present application, components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the present application. In addition, the present application may repeat reference numerals and / or letters in different examples. This repetition is for the purpose of simplification and clarity and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0033] For ease of description, spatial relative relationship terms may be used in the text to describe the relative positional relationship or movement of one element or feature shown in the figure with respect to another element or feature. These relative relationship terms are, for example, "inside", "outside", "inner side", "outer side", "below", "beneath", "above", "over", "front", "rear", etc. Such spatial relative relationship terms are intended to include different orientations of the device during use or operation other than the orientations depicted in the figure. For example, if the device in the figure undergoes a position flip, attitude change, or motion state change, then these directional indications will change accordingly. For example, an element described as "below other elements or features" or "beneath other elements or features" will subsequently be oriented as "above other elements or features" or "over other elements or features". Therefore, the example term "below" can include both the upper and lower orientations. The device can be additionally rotated by 90 degrees or in other directions and the spatial relative relationship descriptors used in the text are interpreted accordingly.

[0034] As Figure 1 shown, in some exemplary embodiments of the present application, a construction method of a waterproof ceramic layer based on an open-cut prefabricated tunnel is provided, which includes the following steps: S10, Excavate the foundation pit, split and crush the soil to obtain a soil-rock mixture.

[0035] S20, Screen the soil-rock mixture to separate the aggregate and coarse clay particles.

[0036] S30, Fabricate and assemble tunnel structural members on-site with the aggregate to form a tunnel structure.

[0037] S40, Fabricate a waterproof ceramic coating with the coarse clay particles and form a waterproof ceramic layer on the surface of the tunnel structure.

[0038] Through the above process, the soil can be directly processed on-site into tunnel structural members and a waterproof ceramic coating, and a waterproof ceramic layer is formed on the surface of the tunnel structure. This not only effectively avoids problems such as low construction efficiency and extended construction period caused by soil transportation and treatment in traditional construction, but also fully realizes the local utilization of soil, significantly reduces costs, and improves construction benefits.

[0039] In the above embodiment, the foundation pit 1 can adopt a segmented excavation method, and the screening process and the like can be carried out synchronously therewith, thereby further improving the construction efficiency.

[0040] In step S30, the tunnel structural members 0 are fabricated and assembled on-site using aggregates. Construction workers can directly form them by means of 3D printing, realizing on-site printing and curing of the tunnel structural members, enabling the excavation of the tunnel or foundation pit and the installation of the tunnel structural members to be carried out simultaneously, thus saving the transportation time of the tunnel structural members and significantly improving the construction efficiency of the open-cut tunnel.

[0041] It can be understood that the above-described embodiments can be synchronously implemented in each process of the open-cut tunnel, and are not limited to the excavation work of the foundation pit.

[0042] As Figure 2 shown, in some exemplary embodiments of the present application, step S20, screening the soil-rock mixture to separate the aggregates and coarse clay particles, includes the following steps: S21, crushing the soil-rock mixture and controlling its moisture content between 8% and 12%.

[0043] When crushing the soil-rock mixture, some water can be added to avoid dust, and controlling the moisture content after crushing can avoid over-wetting and caking, or over-drying and dusting.

[0044] The specific control method can adopt the method of natural drying.

[0045] During specific operation, the crushing process is to crush the oversized soil-rock mixture. At this time, it is convenient for transportation and screening, and will not cause high damage to the machine.

[0046] As Figure 2 shown, in some exemplary embodiments of the present application, further, screening the soil-rock mixture includes the following steps: S22, screening the soil-rock mixture with a sieve mesh having an aperture of 5 mm to 10 mm to obtain a preliminarily screened mixture. It is mainly used to remove large particles such as residual stones.

[0047] S23, screening the preliminarily screened mixture with a sieve mesh having an aperture of 200 μm to 400 μm to separate the aggregates and the secondarily screened mixture. It is mainly used to remove residual coarse particles.

[0048] In one embodiment, the sieve mesh for separating the aggregates and the secondarily screened mixture is preferably a sieve mesh with an aperture of 300 μm.

[0049] S24, screening the secondarily screened mixture with a sieve mesh having an aperture of 100 μm to 180 μm to separate the coarse clay particles.

[0050] In one embodiment, the sieve mesh for separating the coarse clay particles is preferably a sieve mesh with an aperture of 150 μm.

[0051] The step-by-step screening method can effectively separate the soil-rock mixture to obtain aggregates and coarse clay particles.

[0052] The soil and stones in the soil-rock mixture are preliminarily separated, and the soil part is collected. A sieve with a pore size of 5 mm to 10 mm removes residual coarse particles. As Figure 3 shown, in some exemplary embodiments of the present application, making a waterproof ceramic coating with coarse clay particles includes the following steps: S41, grinding the coarse clay particles to obtain coarse clay particles with a particle size of 20 μm to 40 μm. This can make the coarse clay particles uniform and facilitate subsequent preparation procedures.

[0053] S42, adjusting the viscosity of the coarse clay particles to 3000 mPa・s to 8000 mPa・s. The viscosity of the coarse clay particles in this range belongs to the most suitable range for bonding with concrete mortar.

[0054] As Figure 4 shown, in some exemplary embodiments of the present application, adjusting the viscosity of the coarse clay particles to 3000 mPa・s to 8000 mPa・s includes the following steps: S421, adding an antifoaming agent, a dispersant, a thickening agent, and a functional filler to the coarse clay particles. The functional filler at least includes a pH regulator and a preservative, and grinding for at least 90 min to form a preliminary slurry. It is used to adjust the viscosity of the coating.

[0055] S422, adding a film-forming agent and a leveling agent to the preliminary slurry and continuing to grind for at least 20 min to form a mixed slurry.

[0056] The purpose of grinding is to reduce the particle size of the mixture and improve the homogenization degree of the coating, so that the particles are uniformly and stably dispersed in the resin system under the action of shear force, and the coating is more uniform and reliable.

[0057] In some exemplary embodiments of the present application, the main reagents used in the process of making a waterproof ceramic coating with coarse clay particles are as follows: Antifoaming agent: Its function is to eliminate the bubbles generated during production and construction and avoid coating pinholes. Specifically, an organosilicon antifoaming agent (BYK-024) can be selected, which is compounded by polydimethylsiloxane and a low-foaming surfactant.

[0058] Dispersant: Its function is to ensure the uniform dispersion of the filler, prevent agglomeration, and improve the stability of the coating. An organic polymer dispersant (BYK-154) can be selected, which belongs to a dispersant based on ammonium polyacrylate salt.

[0059] Waterproofing agent: Its function is to endow the waterproof ceramic coating with hydrophobicity and improve the waterproof performance. An organosilicon-modified resin waterproofing agent can be selected, which is made of polydimethylsiloxane. Thickener: Its function is to adjust the viscosity of the slurry coating, prevent sagging, and enhance the construction performance. Synthetic polymer thickeners (such as ASE-60), which belong to polyurethane thickeners, can be selected.

[0060] Film-forming agent: Its function is to endow the coating with core functions such as high adhesion, long-term waterproofing, weather resistance, and durability. Waterborne epoxy resin can be selected. As the main film-forming substance of the coating, waterborne epoxy resin forms a continuous and dense network structure through a curing reaction, tightly binding the ceramic substrate with fillers and additives.

[0061] Leveling agent: Its function is to help the coating form a uniform and smooth coating, improve the fluidity of the coating film, and reduce surface defects (such as orange peel and brush marks). Organoalgae waterborne leveling agent BYK-333, which is made of polyether-modified polydimethylsiloxane, can be selected.

[0062] Functional fillers include nano-silica and mica powder. Their function is to increase the hardness of the coating, reduce the porosity, and overall enhance the mechanical and waterproof properties of the waterproof ceramic.

[0063] Before step S421, the coarse clay particles can also be mixed and recycled with purchased powders such as bauxite, aluminum tailing waste, and waste porcelain powder in accordance with a suitable formulation ratio to increase the physical and chemical properties of the coating and meet the usage requirements.

[0064] As Figure 4 shown, in some exemplary embodiments of the present application, after forming the mixed slurry, the following steps are further included: S423, filtering the mixed slurry with a filter screen having a pore size of 25 μm to 50 μm. To avoid sediment or agglomerates and reduce the possibility of blockage in subsequent operations.

[0065] In one embodiment, a sieve with a pore size of 30 μm is preferably used.

[0066] As Figure 4 shown, in some exemplary embodiments of the present application, after forming the mixed slurry, the following steps are further included: S424, pressing the mixed slurry into a sheet-shaped ceramic green body.

[0067] S425, directly radiating and heating the sheet-shaped ceramic green body with an ultra-fast high-temperature sintering process to obtain a solidified ceramic blank.

[0068] Specifically, the pressed ceramic green body is placed between two joule-heated carbon tapes and the ultra-fast high-temperature sintering process is realized in a closed inert atmosphere. The ceramic green body is rapidly heated by direct radiation and heat conduction to form a uniform high-temperature environment to achieve rapid solid-state reactions and reaction sintering. This method can reach a sintering temperature as high as 3000 °C in about 10 seconds.

[0069] S426. Grind the cured ceramic blank for at least 90 minutes until the particle size of the cured ceramic blank is between 20 μm and 40 μm, and add coating additives to form a waterproof ceramic coating. The materials that can be added here include, but are not limited to, solvents such as water and thickeners.

[0070] In some exemplary embodiments of the present application, in the step after forming the mixed slurry, the coating additives added during the grinding of the cured ceramic blank include: functional additives such as wetting agents, antibacterial agents, and flame retardants. Their functions are as follows: Wetting agent: Its function is to improve the wettability of the coating to the substrate and enhance the coating adhesion. A non-ionic surfactant (TritonX-100) can be selected.

[0071] Antibacterial agent: Its function is to inhibit the growth of microorganisms on the coating surface in the dark and humid environment of the tunnel. Quaternary ammonium salt-based organic antibacterial agents can be selected.

[0072] Flame retardant: Its function is to improve the fire resistance of the waterproof ceramic coating. Aluminum hydroxide and silicon-based inorganic compound flame retardants can be selected. Coupling agent: Its function is to enhance the interfacial bonding between inorganic fillers and organic resins and solvents. A silane coupling agent (KH-550) can be selected.

[0073] After adding coating additives to the cured ceramic blank, grind it for at least 90 minutes until the coating particle size is approximately between 20 μm and less than 40 μm to meet the spraying requirements of the waterproof coating at the construction site.

[0074] Before step S426, the cured ceramic blank can also be processed, such as cutting and grinding, etc. to make it into a block shape.

[0075] In some exemplary embodiments of the present application, the coating additives at least include wetting agents, antibacterial agents, flame retardants, and coupling agents.

[0076] In some exemplary embodiments of the present application, before the foundation pit excavation, the following steps are further included: Extract the foundation pit soil at the construction site; Monitor the soil type, moisture content, plasticity index, and impurity content of the foundation pit soil; According to the soil type, moisture content, plasticity index, impurity content, the preparation material ratio of the waterproof ceramic coating, and the coating layer area and thickness of the foundation pit, calculate the usage amounts of the soil-rock mixture, auxiliary solvent, and functional filler. The proportion of the soil-rock mixture usage amount is between 40% and 60%, the proportion of the auxiliary solvent usage amount is between 25% and 45%, and the proportion of the functional filler usage amount is between 10% and 15%. The above settings can facilitate the purchase of auxiliary solvents and functional fillers.

[0077] In some embodiments, before using foundation pit soil in the preparation of waterproof ceramic coatings, a small amount of soil is extracted at the construction site for soil testing. Key parameters such as soil type, moisture content, plasticity index, and impurity content are measured to aid in the pre-purchase and proportioning of solvents and fillers, reducing procurement costs and time. Because the foundation pit soil is subjected to particle size screening and filtration and purification of impurities and organic matter, the resulting coarse clay particles are small in size and meet the required purity standards for the preparation of waterproof ceramic coatings.

[0078] In some embodiments, the relative contents of clay, required auxiliary solvents, and fillers in the total formulation are as follows: Clay 40%~60%; nano-silica 5%~10%; mica powder 5%; film-forming agent 20%~30%; defoaming agent 0.2%~1.5%; dispersant 0.5%~2%; curing agent 5%; leveling agent 0.2%~1.5%; wetting agent 0.1%~0.5%; thickener 0.2%~1.5%; waterproofing agent 1%~5%; coupling agent 0.5%~2%.

[0079] Auxiliary solvents and functional fillers can be purchased in advance based on the above approximate relative content reference, and the proportion of ingredients can be changed according to the following specific conditions and construction requirements.

[0080] In some embodiments, for high-purity, fine-particle clay, the dispersant content is 0.5%. If the clay still contains a lot of impurities after purification, the dispersant content needs to be increased to 1%-2%. For clay with a high moisture content (≥12%), the film-forming agent content needs to be increased to 30%-35%. For clay with poor plasticity, the wetting agent content needs to be increased to (0.3%-0.5%). The curing agent ratio is generally 15%-20% of the film-forming agent mass (two-component system). For projects requiring high water resistance of waterproof ceramic coatings, the waterproofing agent can be added to 5%; nano-silica can be added to 10%. Since it is used to make spray-type waterproof ceramic materials, the thickener dosage should be lower (0.2%-0.8%).

[0081] In an optional embodiment, the construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel is as follows: Screening of the soil-rock mixture: The excavated foundation pit soil is a soil-rock mixture, which undergoes preliminary processing. On-site crushing and screening components effectively separate the soil-rock mixture and crush the rocks to the desired particle size. This system offers a compact process, simple operation, and high processing efficiency.

[0082] Use crushing components to crush large pieces of soil and rock mixture, and let the crushed soil and rock mixture dry naturally until the moisture content is 8% to 12% to avoid excessive wetting and agglomeration, or excessive drying and dust generation.

[0083] After that, it is fed into the screening component. First, the first-layer screen is replaced with a screen with a pore size of 5 mm to 10 mm. When the motor drives the screen bar to rotate at a high speed, under the action of the centrifugal force field, the soil and stone particles are subjected to different centrifugal forces due to significant differences in particle size and specific gravity. At the same time, the motor also drives the rotating drum 48 below the screen bar to rotate. The gravel and stones above the screen are discharged from the discharge port, and the soil particles below the screen are discharged by the action of the rotating drum 48.

[0084] After the soil and stones in the mixture are preliminarily separated, the soil part is collected. At this time, the first-layer screen is replaced with a 50-mesh (300 microns) screen to remove residual coarse particles (mainly from particles that do not meet the crushing process).

[0085] At the same time, the second-layer screen is replaced with a 100-mesh (150 microns) screen to obtain the main material for making ceramics, that is, coarse clay particles. The waterproof ceramic coating is a ceramic material for construction, which needs to take into account both strength and forming efficiency. The collected soil that has been preliminarily separated from the stones is fed into the screening component 40, ensuring uniform feeding and controlling the speed to avoid overloading the screen. The multi-layer screen separates step by step. The required fine particles come out from the lower discharge port through centrifugal screening. The coarse particles remain on the two-stage screen, waiting to return to the crusher or be discharged for waste treatment from the coarse material discharge port. If different particle size requirements are needed to make waterproof ceramic coatings of different quality grades and uses, different thickness and particle size particles can be obtained by replacing the screen to achieve the purpose. Different particle size clays are packaged separately, marked with the mesh number and use.

[0086] The separated sand and stones, that is, aggregates, have a particle size generally within 3 mm to 5 mm, meeting the requirements for making daily fine aggregates. If finer aggregates or construction mortar need to be made, they are poured into the crusher for further crushing treatment. According to the particle size requirements, different degrees of multi-stage crushing devices can be selected to adjust the crushing particle size of the stones. The crushed stones with different particle sizes are collected separately and used for making aggregates with different particle sizes.

[0087] The aggregates are washed to remove the soil and impurities on the surface, and then dried. According to the concrete formula, the aggregates are mixed with other raw materials (such as cement, water, etc.), and the mixture is fully stirred by using stirring equipment, and then poured into the storage tank for standby.

[0088] After that, soil purification is carried out: The separated soil mass needs to be further processed and purified. First, the soil mass is washed to remove the sediment in the soil mass, and then the further purification method is determined according to the soil conditions in the excavation area (such as organic matter content, impurity content, metal mineral content or soil cohesion, etc.).

[0089] For the production of waterproof ceramic coatings, soil with high-precision purification is required. However, the content of impurity organic matter in the on-site foundation pit soil is too high, and the soil conditions are not as good as those of the kaolin and bentonite used in traditional porcelain firing. Therefore, an innovative comprehensive purification method is adopted, which combines physical and chemical methods to achieve high-efficiency purification.

[0090] First, add an appropriate amount of acid-base solvent to react chemically with the impurities to form soluble salts or compounds. Subsequently, remove these impurities through washing and filtration to improve the purity of the soil. Then, through membrane separation technology, that is, utilizing the selective permeability of the semi-permeable membrane, different components in the soil are separated. By adjusting the pore size of the membrane and operating conditions, effective separation and purification of different components can be achieved. Or in the second step, other physical methods (such as ultrasonic waves, centrifugal separation, etc.) can be used for further purification.

[0091] The purified soil needs to be dried for subsequent use in sintering ceramics. First, a small amount of soil should be purified through the above method for ceramic firing to test its working performance, and then adjust and optimize the purification method according to the actual situation.

[0092] In addition, during the purification process, the purification effect should be regularly detected, and the purification method and parameters should be adjusted in a timely manner to obtain the best purification effect.

[0093] In fact, the specific purification method to be adopted should also be optimally selected according to the soil conditions and purification purposes.

[0094] The above two methods can be comprehensively processed to obtain soil with low impurities and high-precision purification. Using this purification technology can significantly reduce production costs and avoid environmental pollution.

[0095] In some embodiments of this application, it is proposed that the prepared waterproof ceramic coating will be coated on the surface of the concrete mortar, and the concrete mortar is pre-sprayed to cover the exposed surfaces on both sides of the foundation pit, which can play a supporting role. As an underground facility, the waterproof, anti-seepage and corrosion resistance of the prefabricated tunnel are the key to preparing the waterproof coating, and an important task of this prefabricated tunnel construction method is to shorten the construction period, reduce the cost and be safe and reliable.

[0096] In addition, in some embodiments of this application, a new ceramic sintering preparation method is adopted, that is, an ultra-fast high-temperature sintering process realized by radiation heating in an inert gas. This method can reach a sintering temperature as high as 3000 °C in an extremely short time (about 10 seconds), meeting the requirements of on-site rapid preparation and application.

[0097] The specific construction method is as follows: The purified and dried foundation pit soil is ground into fine powder, and powders such as bauxite, aluminum tailing waste, and waste porcelain powder are purchased and recycled by mixing. Functional fillers such as defoamers, dispersants, thickeners, and other auxiliaries (such as pH regulators, preservatives, etc.) are added according to appropriate formula ratios and on-site requirements to adjust the viscosity of the coating to the most suitable range for bonding with concrete mortar and improve the performance and stability of the coating.

[0098] The slurry obtained after mixing and grinding for 1.5 hours is then added with a film-forming agent and a leveling agent and stirred and mixed. The film-forming agent, as the film-forming substance, will form a continuous coating film after the coating dries, playing a bonding and protecting role. Continue grinding for more than 20 minutes. The grinding is all carried out by a sand mill. The purpose of grinding is to reduce the particle size of the mixture and improve the homogenization degree of the coating, so that the particles are evenly and stably dispersed in the resin system under the action of shear force. Then, it is filtered and encapsulated with a 30-micron filter hole for standby.

[0099] Take out part of the mixture and obtain a sheet-shaped ceramic green body through a pressing process. Place the pressed ceramic sheet between two Joule-heated carbon tapes and carry out the ultra-fast high-temperature sintering (UHS) process in a closed inert atmosphere.

[0100] The ceramic sheet is rapidly heated by direct radiation and heat conduction to form a uniform high-temperature environment to achieve rapid solid-state reactions and reaction sintering. This method can reach a sintering temperature as high as 3000 °C in about 10 seconds. Then, techniques such as SEM (scanning electron microscope), XRD (X-ray diffraction), and electrochemical measurements are used to evaluate the microstructure and performance of the UHS-sintered ceramic materials. Optimize and adjust the mixture ratio and purification technical methods according to the measured data results.

[0101] The fired ceramic materials need to be processed, such as through processes like cutting and grinding to make them into blocks, and then the processed ceramic materials are ground into fine powder and made into a coating by adding solvents such as water and thickeners and stored in a storage tank for spraying construction.

[0102] Perform performance tests on the prepared waterproof ceramic spraying material, including indicators such as water absorption rate, water resistance, and weather resistance, to ensure that it meets the usage requirements and has good waterproof performance. Pour the waterproof ceramic coating into the storage tank for standby, connect it to the spraying equipment through the discharge pipe, and ensure that the spraying equipment, spray gun, etc. are in good condition. Before spraying, pay attention to controlling the coating thickness and uniformity, and adjust parameters such as spraying pressure and spraying distance.

[0103] Relationships of each step: The basic process of each step is carried out in chronological order, and there can also be overlaps in time. As shown in the appendix Figure 6As shown, the on-site foundation pit is excavated in sections, the soil in the foundation pit is cleared, and large pieces of hard rock are split and crushed for subsequent Step 1: earth-rock screening, Step 2: soil purification, and production of fine sand and gravel aggregates. The fine aggregates will be used to produce concrete mortar as the raw materials for the concrete required for the support of Foundation Pit 1 and the printing of prefabricated tunnel components. After the earth-rock screening in Step 1, the soil completed by the preliminary screening in Step 2 will be further purified with high precision by the comprehensive purification method, and then Step 3: production and spraying of waterproof ceramic coatings will be carried out. The waterproof ceramic coatings will be sprayed on the surface of the foundation pit and the inner surface of the prefabricated tunnel components to form a double-layer waterproof lining, greatly improving the waterproof and anti-seepage performance of the tunnel. During the actual construction process, parallel operations in terms of time can be carried out for each step to improve construction efficiency and shorten the operation period.

[0104] As Figures 5 to 10 , exemplary embodiments of the present application also provide a tunnel construction equipment, which is applied to the implementation of the construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel as described in any one of the above embodiments. The tunnel construction equipment includes: A mixing component 20, the mixing component 20 includes a mixing tank 21, and the waterproof ceramic coating is stored in the mixing tank 21; A spraying component 30, which is communicated with the mixing tank 21 and includes a driving structure 31 and a spraying output end 32; A control component, which is electrically connected to the mixing component 20 and the spraying component 30 to drive the driving structure 31 to drive the spraying output end 32 to form a waterproof ceramic coating on the surface of the tunnel structure member 60.

[0105] As Figure 9 shown, in some exemplary embodiments of the present application, the driving structure 31 is a robotic arm. The driving structure 31 of the robotic arm includes a base 311, a rotating support 312, a feeding port 313, a shoulder joint 314, a large arm 315, an elbow joint 316, a small arm 317, and a wrist joint 318.

[0106] In some exemplary embodiments of the present application, the tunnel construction equipment further includes a screening component 40. The screening component 40 at least includes a screen with a pore size of 5 mm to 10 mm, a screen with a pore size of 200 μm to 400 μm, and a screen with a pore size of 100 μm to 180 μm. The screening component 40 includes a screening machine body 41, a sieve device bin 42, a screening motor 43, a console 44, a sand and gravel discharge port 45, a soil particle discharge port 46, a rotating shaft 47, and a rotating drum 48.

[0107] In some exemplary embodiments of the present application, the tunnel construction equipment further includes a crushing component 50 for crushing soil, which can specifically be a roller crusher or a splitting and crushing device. The crushing component 50 includes a feeding hopper 51, a crushing motor 52, a crusher frame 53, roller teeth 54, a crushing chamber 55, and a crusher discharge port 56.

[0108] In some exemplary embodiments of the present application, refer to Figure 5 the on-site working drawing. During the segmented excavation of the foundation pit 10, the excavated soil in the foundation pit is subjected to splitting and crushing treatment to obtain a mixture of soil and stone. The mixture of soil and stone is poured into the screening assembly 40 for screening of soil and stone to separate the aggregate and coarse clay particles. The initially screened coarse clay particles still need to be treated by the comprehensive purification method to obtain a mixed slurry. The mixed slurry is made into a waterproof ceramic coating through ceramic sintering and coating production, and is filled into the mixing tank 21 of the mixing assembly 20. Finally, it is connected to the spraying assembly 30 through the discharge pipe to ensure the smooth transportation of the waterproof ceramic coating and the smooth progress of the spraying work.

[0109] In some alternative embodiments, the sand and gravel materials screened out by the screening assembly 40 are poured into the adjacent crushing assembly 50 for further crushing treatment. According to the particle size requirements of the fine sand and gravel aggregate, different levels of grading devices can be selected to adjust the crushing particle size of the stones. The fine aggregate is used for subsequent support of the foundation pit 10 and in-situ printing of assembly components.

[0110] Figure 5 Figure 40 shows the screening assembly 40 - screening machine equipment adopted in an embodiment of the present application, and its specific operation process is as follows: The mixture of soil and stone after preliminary crushing treatment is poured into the hopper 42 of the sieve device of the screening machine equipment in batches. The screening motor 43 is started through the console 44. When the motor drives the rotating shaft 47 to rotate at a high speed, the rotating shaft 47 drives the impeller of the upper rotating drum 48 to rotate. Under the action of the centrifugal force field, the soil and stone particles are subjected to different centrifugal forces due to significant differences in particle size and specific gravity. The gravel and stones remaining on the sieve are discharged from the sand and gravel discharge port 45, and the soil particles under the sieve are discharged from the lower soil particle discharge port 46 by the action of the rotating drum 48, thereby separating the soil and stones in the mixture. The soil part is collected, and the soil particles are screened through multiple sieves and the above process is repeated to obtain coarse clay particles with the required particle size for subsequent uses such as making waterproof ceramic coatings.

[0111] Figure 7 and Figure 8 Figure 50 shows the crushing assembly 50 - roll crusher adopted in an embodiment of the present application, and its specific operation process is as follows: The mixture of soil and stone in the foundation pit generated by excavation or the sand and gravel materials that need to be further processed into finer particle sizes are poured into the discharge port 56 of the roll crusher. The crusher motor 52 is started, and the multi-stage toothed rolls 54 on both sides in the crushing chamber 55 rotate periodically to crush the sand and gravel particles into fine aggregates to make the required small particle sizes. After reaching the required particle size, it is discharged from the discharge port 56 of the crusher for subsequent production of fine aggregates for concrete and in-situ printing of assembly components.

[0112] Figure 9Figure 30 shows the spraying assembly 30 - a spraying robotic arm equipment adopted in an embodiment of the present application, and its specific operation process is as follows: The main body of the equipment is a multi-degree-of-freedom robotic arm. The base 311 can be placed on the working surface or the trailer surface. The feed inlet 313 is connected to the storage tank through a discharge pipe to ensure the transportation and spraying of the waterproof ceramic coating. The swing, the large and small arms (the large arm 315 and the small arm 317), and the front spray gun are controlled by the rotating support 312, the shoulder joint 314, the elbow joint 316, and the wrist joint 318 to be combined at any angular position to spray the waterproof ceramic coating onto the surface of the foundation pit 10 and the inner surface of the tunnel assembly members. This greatly reduces the time required for spraying and the human and material resources consumed.

[0113] Figure 9 Figure 31 shows the mixing assembly 20 adopted in an embodiment of the present application. The mixing tank 21 of the mixing assembly 20 can store and supply the raw materials required for on-site construction, such as waterproof coatings, concrete, sand and gravel fine aggregates, etc. A mixing device, such as a mixing paddle, can be arranged inside to avoid sedimentation.

[0114] Specifically, on-site workers climb the production ladder 26, open the head 22 to pour the raw materials into the storage tank, connect the discharge pipe to the flange outlet 23, and connect it to the feed inlet 313 on the spraying robotic arm to ensure the smooth transportation of the waterproof ceramic coating and the smooth progress of the subsequent spraying work. The support seat 25 and the upper saddle 24 ensure the stable placement of the storage tank.

[0115] The above embodiments have the following advantages: 1. The foundation pit soil is processed and fired into ceramics and made into a waterproof ceramic coating. By using scientific and advanced soil screening and purification technology and high-temperature ceramic firing technology, the ceramic particles not only maintain high strength and durability but also have excellent waterproof performance. The production cost of the waterproof ceramic coating is reduced, and the high-strength, durable, water-stopping, flame-retardant, environmentally friendly and harmless waterproof ceramic coating is used on the contact surface between the foundation pit soil and the assembly and the inner surface of each assembly member. A double-layer strong waterproof barrier is formed, reducing the cost generated by subsequent repairs due to water leakage, and providing a solid guarantee for the long-term stable operation of the open-cut precast tunnel.

[0116] 2. A high utilization rate of the earthwork is achieved, providing new ideas and paths for the purification and utilization of foundation pit soil and stone resources, avoiding the turnover and waste of foundation pit soil and stone resources, and reducing the turnover and transportation costs of foundation pit soil. Compared with traditional waterproof materials, this waterproof ceramic coating made from foundation pit soil not only has significant economic advantages but also better conforms to the current concept of green environmental protection and sustainable development. It has excellent economic, environmental and social benefits. Therefore, its popularization and application will inject new vitality into the technological innovation and development of open-cut precast tunnels and related fields.

[0117] It should be understood that the present application does not limit its application to the detailed structure and arrangement of the components presented in the present application. The present application is capable of having other embodiments and can be implemented and carried out in various ways. The foregoing variations and modifications fall within the scope of the present application. It should be understood that the present application, as disclosed and defined herein, extends to all alternative combinations of two or more separate features mentioned or evident in the text and / or the drawings. All such different combinations constitute multiple alternative aspects of the present application. The embodiments of the present application illustrate the best mode known for implementing the present application and will enable those skilled in the art to utilize the present application.

Claims

1. A construction method of a waterproof ceramic layer for an open-cut prefabricated tunnel, characterized in that, It includes the following steps: Excavate the foundation pit, split and crush the soil to obtain a mixture of soil and stone; Screen the mixture of soil and stone to separate the aggregate and coarse clay particles; On-site fabricate and assemble tunnel structural members with the aggregate to form a tunnel structure; Fabricate a waterproof ceramic coating with the coarse clay particles and form a waterproof ceramic coating on the surface of the tunnel structure.

2. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 1, characterized in that, Screen the mixture of soil and stone to separate the aggregate and coarse clay particles, including the following steps: Crush the mixture of soil and stone and control its moisture content between 8% and 12%; 3. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 2, characterized in that, Screen the mixture of soil and stone, including the following steps: Screen the mixture of soil and stone with a sieve mesh with a pore size of 5 mm to 10 mm to obtain a preliminary screened mixture; Screen the preliminary screened mixture with a sieve mesh with a pore size of 200 μm to 400 μm to separate the aggregate and the second screened mixture; Screen the second screened mixture with a sieve mesh with a pore size of 100 μm to 180 μm to separate the coarse clay particles.

4. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 3, characterized in that, Fabricate a waterproof ceramic coating with the coarse clay particles, including the following steps: Grind the coarse clay particles to obtain coarse clay particles with a particle size of 20 μm to 40 μm; Adjust the viscosity of the coarse clay particles to 3000 mPa・s to 8000 mPa・s.

5. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 4, characterized in that, Adjust the viscosity of the coarse clay particles to 3000 mPa・s to 8000 mPa・s, including the following steps: Add an antifoaming agent, a dispersant, a thickening agent and functional fillers to the coarse clay particles. The functional fillers at least include a pH regulator and a preservative, and grind for at least 90 min to form a preliminary slurry; Add a film-forming agent and a leveling agent to the preliminary slurry and continue to grind for at least 20 min to form the mixed slurry.

6. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 5, characterized in that, After forming the mixed slurry, it further includes the following steps: Filter the mixed slurry with a filter screen with a pore size of 25 μm to 50 μm.

7. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 5, characterized in that, After forming the mixed slurry, it further includes the following steps: Press the mixed slurry into a sheet-shaped ceramic green body; Directly radiatively heat the sheet-shaped ceramic green body with an ultra-fast high-temperature sintering process to obtain a solidified ceramic green body; Grind the solidified ceramic green body for at least 90 min until the particle size of the solidified ceramic green body is between 20 μm and 40 μm, and add coating aids to form the waterproof ceramic coating.

8. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to claim 7, characterized in that, The coating aids at least include a wetting agent, an antibacterial agent, a flame retardant and a coupling agent.

9. The construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel according to any one of claims 1 to 8, characterized in that, Before excavating the foundation pit, it further includes the following steps: Extract foundation pit soil at the construction site; Monitor the soil type, moisture content, plasticity index and impurity content of the foundation pit soil; According to the soil type, the moisture content, the plasticity index, the impurity content, the preparation material ratio of the waterproof ceramic coating, and the coating layer area and thickness of the foundation pit, calculate the amount of the mixture of soil and stone, the amount of auxiliary solvent and the amount of functional fillers. The proportion of the amount of the mixture of soil and stone is between 40% and 60%, the proportion of the amount of auxiliary solvent is between 25% and 45%, and the proportion of the amount of functional fillers is between 10% and 15%.

10. A tunnel construction equipment, characterized in that, The tunnel construction equipment is applied to the implementation of the construction method of the waterproof ceramic layer based on the open-cut prefabricated tunnel as described in any one of claims 1 to 9, and is characterized in that it includes: A mixing assembly, the mixing assembly includes a mixing tank, and the waterproof ceramic coating is stored in the mixing tank; A spraying assembly, which is communicated with the mixing tank and includes a driving structure and a spraying output end; A control assembly, which is electrically connected to the mixing assembly and the spraying assembly to drive the driving structure to drive the spraying output end to form a waterproof ceramic coating on the surface of the tunnel structural member.

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