Method for enhancing waterproof performance of immersed tunnel with ultra-wide section and composite coating thereof

Abstract

The invention provides a method for enhancing waterproof performance of an immersed tunnel with an ultra-wide section and a composite coating thereof, and the method comprises the following steps: checking, cleaning and repairing a concrete surface on the immersed tunnel to obtain a concrete base layer with a flat surface; a first epoxy resin coating with the thickness of 0.1 mm is laid on the concrete base layer; spraying a polyurea coating with the thickness of 1.0 mm on the first epoxy resin coating; a second epoxy resin coating with the thickness of 0.1 mm is laid on the polyurea coating; linen fiber cloth is laid on the second epoxy resin coating; spraying a polyurethane coating with the thickness of 0.5 mm on the linen fiber cloth; and the first epoxy resin coating is the same as the second epoxy resin coating. According to the laying method, a flat and firm protective layer is formed on the concrete base layer, so that the waterproofness of the joints or weak parts of the pipe sections of the immersed tunnel is enhanced, and the safety and reliability of the immersed tunnel are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of immersed tube tunnels, and in particular relates to a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel and a composite coating thereof. Background Art

[0002] With the acceleration of urbanization, tunnels have become an indispensable part of the urban transportation system. Their construction and maintenance are crucial to ensure smooth traffic and safe travel for citizens. In view of the surge in urban transportation demand, the design of ultra-wide section immersed tube tunnels has attracted widespread attention with its unique advantages. However, the construction of such tunnels faces multiple challenges: when subjected to huge loads, the tunnel structure is prone to cracks and deformation; coupled with the widespread application of immersed tube tunnel technology in inland river transportation, the settlement problem caused by the uneven geology of the bottom of the inland river further aggravates the formation of cracks; at the same time, the complex and changeable water flow environment of the inland river, after long-term scouring and erosion, puts higher requirements on the anti-seepage performance of the tunnel. In view of this, strengthening the anti-permeability construction of ultra-wide section immersed tube tunnels has become a key issue that needs to be solved at present.

[0003] That is, how to provide a method for enhancing the waterproof performance of ultra-wide section immersed tube tunnels by laying multiple layers of coating on the concrete base surface of the immersed tube tunnel to improve the waterproofness of the joints or weak points of the immersed tube tunnel sections, thereby ensuring the safety and reliability of the immersed tube tunnel, is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0004] The object of the present invention is to provide a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel and a composite coating thereof, so as to solve at least one of the above-mentioned technical problems.

[0005] To achieve the above-mentioned purpose, the first aspect of the present invention provides a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel, the method comprising the following steps: inspecting, cleaning and repairing the concrete surface on the immersed tube tunnel to obtain a concrete base with a smooth surface; laying a first epoxy resin coating with a thickness of 0.1 mm on the concrete base; spraying a polyurea coating with a thickness of 1.0 mm on the first epoxy resin coating; laying a second epoxy resin coating with a thickness of 0.1 mm on the polyurea coating; laying a linen fiber cloth on the second epoxy resin coating; spraying a polyurethane coating with a thickness of 0.5 mm on the linen fiber cloth; wherein the first epoxy resin coating and the second epoxy resin coating are the same.

[0006] In the first aspect, the inspection and cleaning of the concrete surface on the immersed tube tunnel to obtain a concrete base with a smooth surface includes the following steps: comprehensively inspecting the concrete surface on the immersed tube tunnel to remove impurities and obtain a first clean concrete surface; polishing the first clean concrete surface to obtain a flat second clean concrete surface; deeply cleaning the second clean concrete surface by a high-pressure water gun or sandblasting equipment to obtain a third clean concrete surface that is oil-free, dust-free and dry; and repairing the third clean concrete surface to obtain a concrete base with a smooth surface.

[0007] In the first aspect, the repairing of the third clean surface of the concrete specifically includes: finding cracks, pores or pits on the third clean surface of the concrete to form a repair area; filling the repair area with repair material, and after drying and curing, obtaining a concrete base with a smooth surface and no depressions.

[0008] In the first aspect, laying a first epoxy resin coating with a thickness of 0.1 mm on the concrete base comprises: mixing epoxy resin glue and epoxy curing agent in a mass ratio of 1:1, stirring evenly, and standing for 5 to 10 minutes to obtain epoxy resin coating; brushing the epoxy resin coating evenly on the concrete base; drying at room temperature to form a first epoxy resin coating with a thickness of 0.1 mm on the concrete base; wherein the bonding strength of the first epoxy resin coating to the concrete base is greater than 2.5 MPa.

[0009] In the first aspect, the method of spraying a polyurea coating with a thickness of 1.0 mm on the first epoxy resin coating comprises: mixing a polyurea resin and an isocyanate curing agent in a mass ratio of 1:1, stirring evenly, and obtaining a polyurea coating; spraying the polyurea coating on the first epoxy resin coating for the first time to form a polyurea initial coating with a thickness of 0.5 mm on the first epoxy resin coating; after standing for 3 hours, spraying the polyurea coating on the polyurea initial coating for the second time to form a polyurea secondary coating on the polyurea initial coating, and the thickness of the polyurea coating composed of the polyurea initial coating and the polyurea secondary coating is 1.0 mm; curing the polyurea coating, and the curing time exceeds 24 hours.

[0010] In the first aspect, after the first epoxy resin coating is laid, the polyurea coating is evenly sprayed on the first epoxy resin coating within 4 to 24 hours.

[0011] In the first aspect, after the second epoxy resin coating is laid, the linen fiber cloth is laid on the second epoxy resin coating within 1 hour.

[0012] In the first aspect, after the flax fiber cloth is laid, the polyurethane coating is evenly sprayed on the flax fiber cloth 24 hours later.

[0013] The second aspect of the present invention provides a composite coating for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel. The composite coating is suitable for the method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel described in the first aspect, and is used to improve the waterproof and anti-permeability of the concrete base on the immersed tube tunnel. The composite coating includes: a first epoxy resin coating, the thickness of the first epoxy resin coating is 0.1 mm, and it is arranged on the top of the concrete base; a polyurea coating, the thickness of the polyurea coating is 1.0 mm, and it is arranged on the top of the first epoxy resin coating; a second epoxy resin coating, the thickness of the second epoxy resin coating is 0.1 mm, and it is arranged on the top of the polyurea coating; a linen fiber cloth, which is arranged on the top of the second epoxy resin coating; a polyurethane coating, the thickness of the polyurethane coating is 0.5 mm, and it is arranged on the top of the linen fiber cloth; wherein the first epoxy resin coating and the second epoxy resin coating are the same.

[0014] In the second aspect, the adhesion of the composite coating to the concrete base is 4.5 MPa; the anti-seepage pressure of the composite coating is greater than 1.6 MPa.

[0015] Beneficial effects:

[0016] The present invention provides a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel. First, the concrete surface on the immersed tube tunnel is inspected, cleaned and repaired to obtain a concrete base with a smooth surface, so as to improve the bonding strength between the subsequent coating and the concrete base; secondly, a first epoxy resin coating with a thickness of 0.1 mm is laid on the concrete base, and a polyurea coating with a thickness of 1.0 mm is sprayed on the first epoxy resin coating, and the first epoxy resin coating is used as a binder so that the polyurea coating with high efficiency and waterproofness can be completely covered on the concrete base, so as to improve the waterproofness of the coating, thereby improving the impermeability of the immersed tube tunnel; then, a first epoxy resin coating with a thickness of 0.1 mm is laid on the polyurea coating. The second epoxy resin coating with a thickness of 0.1 mm enables the second epoxy resin coating to fully penetrate into the tiny pores of the polyurea coating during the laying process to form a more solid bonding interface, and a linen fiber cloth is laid on the second epoxy resin coating so that the linen fiber cloth can be evenly covered on the second epoxy resin coating to improve the impact resistance of the coating and further enhance the waterproofness of the immersed tube tunnel; finally, a polyurethane coating with a thickness of 0.5 mm is sprayed on the linen fiber cloth to fill the gaps on the linen fiber cloth, and a solid protective layer is formed after curing, and the coating surface is flat and smooth without defects such as cracks, thereby improving the safety and reliability of the immersed tube tunnel. The present invention inspects, cleans and repairs the concrete surface on the immersed tube tunnel to form a concrete base with a flat surface, and sequentially lays the first epoxy resin coating, polyurea coating, second epoxy resin coating, linen fiber cloth and polyurethane coating on the concrete base to form a flat and solid protective layer on the concrete base, thereby enhancing the waterproofness of the connection or weak points of the immersed tube tunnel sections and ensuring the safety and reliability of the immersed tube tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a flow chart of a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel in the present invention;

[0019] Figure 2 It is a structural schematic diagram of a composite coating for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel in the present invention;

[0020] Reference numerals:

[0021] 1. Concrete base; 2. First epoxy resin coating; 3. Polyurea coating; 4. Second epoxy resin coating; 5. Linen fiber cloth; 6. Polyurethane coating. DETAILED DESCRIPTION

[0022] The technical scheme of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0023] In the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0024] Embodiment 1:

[0025] See also Figure 1-2 The present invention provides a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel, the method comprising the following steps:

[0026] (1) Inspect, clean and repair the concrete surface of the immersed tube tunnel to obtain a concrete base 1 with a smooth surface;

[0027] (2) laying a first epoxy resin coating 2 with a thickness of 0.1 mm on the concrete base layer 1;

[0028] (3) spraying a polyurea coating 3 with a thickness of 1.0 mm on the first epoxy resin coating 2;

[0029] (4) laying a second epoxy resin coating 4 with a thickness of 0.1 mm on the polyurea coating 3;

[0030] (5) Laying a linen fiber cloth 5 on the second epoxy resin coating 4;

[0031] (6) spraying a polyurethane coating 6 with a thickness of 0.5 mm on the flax fiber cloth 5;

[0032] The first epoxy resin coating 2 and the second epoxy resin coating 4 are the same.

[0033] Specifically, the present invention provides a method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel. First, the concrete surface on the immersed tube tunnel is inspected, cleaned and repaired to obtain a concrete base layer 1 with a smooth surface, so as to improve the bonding strength between the subsequent coating and the concrete base layer 1; secondly, a first epoxy resin coating 2 with a thickness of 0.1 mm is laid on the concrete base layer 1, and a polyurea coating 3 with a thickness of 1.0 mm is sprayed on the first epoxy resin coating 2, and the first epoxy resin coating 2 is used as a binder so that the polyurea coating 3 with high efficiency and waterproofness can be completely covered on the concrete base layer 1, so as to improve the waterproofness of the coating, thereby improving the impermeability of the immersed tube tunnel; then ... first epoxy resin coating 2 with a thickness of 1.0 mm is sprayed on the first epoxy resin coating 2, and the first epoxy resin coating 2 is used as a binder so that the polyurea coating 3 with high efficiency and waterproofness can be completely covered on the concrete base layer 1, so as to improve the waterproofness of the coating, thereby improving the impermeability of the immersed tube tunnel; then, a first epoxy resin coating 2 with a thickness of 0.1 mm is laid on the first epoxy resin coating 2, and a first epoxy resin coating 2 with a thickness of 0.1 mm is sprayed on the first epoxy resin coating 2, and a first epoxy resin coating 2 with a thickness of A second epoxy resin coating 4 with a thickness of 0.1 mm is laid on the surface, so that the second epoxy resin coating 4 can fully penetrate into the tiny pores of the polyurea coating 3 during the laying process to form a more solid bonding interface, and a linen fiber cloth 5 is laid on the second epoxy resin coating 4, so that the linen fiber cloth 5 can be evenly covered on the second epoxy resin coating 4 to improve the impact resistance of the coating and further enhance the waterproofness of the immersed tube tunnel; finally, a polyurethane coating 6 with a thickness of 0.5 mm is sprayed on the linen fiber cloth 5 to fill the gaps on the linen fiber cloth 5. After curing, a solid protective layer is formed, and the coating surface is flat and smooth without defects such as cracks, thereby improving the safety and reliability of the immersed tube tunnel. The present invention forms a concrete base 1 with a smooth surface by inspecting, cleaning and repairing the concrete surface on the immersed tube tunnel, and sequentially lays a first epoxy resin coating 2, a polyurea coating 3, a second epoxy resin coating 4, a linen fiber cloth 5 and a polyurethane coating 6 on the concrete base 1 to form a smooth and solid protective layer on the concrete base 1, thereby enhancing the waterproofness of the connection or weak points of the immersed tube tunnel sections and ensuring the safety and reliability of the immersed tube tunnel.

[0034] In some possible implementations, the inspection and cleaning of the concrete surface on the immersed tube tunnel to obtain a concrete base layer 1 with a smooth surface includes the following steps: comprehensively inspecting the concrete surface on the immersed tube tunnel to remove impurities to obtain a first clean concrete surface; polishing the first clean concrete surface to obtain a smooth second clean concrete surface; deeply cleaning the second clean concrete surface with a high-pressure water gun or sandblasting equipment to obtain a third clean concrete surface that is oil-free, dust-free, and dry; and repairing the third clean concrete surface to obtain a concrete base layer 1 with a smooth surface.

[0035] This is because, in order to evenly apply the waterproof coating on the concrete surface of the immersed tube tunnel and provide protection for the immersed tube tunnel, the concrete surface of the immersed tube tunnel needs to be fully cleaned to ensure that the concrete surface is clean, tidy and free of defects. In a specific embodiment, the process of fully cleaning the concrete surface includes the following steps:

[0036] Preliminary cleaning: Before construction, conduct a comprehensive inspection of the concrete surface to remove all visible impurities, such as large concrete fragments, oil stains, paint residues, etc., to ensure that the concrete surface is initially clean and obtain the first clean surface of the concrete;

[0037] Mechanical grinding: Use a special grinding machine or hand-held grinding tool to carefully grind the first clean surface of the concrete until the surface is flat and has no obvious protrusions or depressions, so as to remove the rough part of the surface, the cement slurry layer and the surface layer of tiny cracks, and obtain a flat second clean surface of the concrete;

[0038] Deep cleaning: Use high-pressure water guns or sandblasting equipment to deeply clean the second clean surface of the concrete, thoroughly remove residual dust, particles and tiny impurities, ensure that the surface is dust-free and oil-free, and is in a completely dry state, to obtain the third clean surface of the concrete;

[0039] The third clean surface of the concrete is repaired to obtain a concrete base layer 1 with a smooth surface.

[0040] In some possible implementations, the repairing of the third clean surface of the concrete specifically includes: finding cracks, pores or pits on the third clean surface of the concrete to form a repair area; filling the repair area with repair material, and after drying and curing, obtaining a concrete base 1 with a smooth surface and no depressions.

[0041] Those skilled in the art can understand that the third clean surface of the concrete obtained by high-pressure water pressure or sandblasting equipment may have some defects such as cracks, pores or pits. If these defects are not repaired, the bonding strength between the subsequent first epoxy resin coating 2 and the concrete base 1 will be affected. Therefore, in a specific embodiment, these cracks, pores or pits should be found first, and the corresponding repair materials should be filled. After drying and curing, a concrete base 1 with a smooth surface and no depression is obtained. When there are cracks with a large width on the third clean surface of the concrete, grooves are firstly processed, and then epoxy mortar or special crack repair materials are filled to ensure that the cracks are completely closed and flush with the third clean surface of the concrete; when there are fine cracks on the third clean surface of the concrete, epoxy crack repair agent can be directly applied to close them; when there are pores or pits on the third clean surface of the concrete, epoxy mortar repair putty or special repair materials are used to fill the pores or pits to ensure that the surface of the repaired third clean surface of the concrete is smooth and without depressions. After filling the above-mentioned cracks, pores or pits with repair materials, wait for a period of time to allow the repair materials to cure and dry, so that the repair materials are completely flush with the third clean surface of the concrete, and the strength and stability of the concrete base layer 1 are guaranteed.

[0042] In some possible embodiments, laying a first epoxy resin coating 2 with a thickness of 0.1 mm on the concrete base 1 includes: mixing epoxy resin glue and epoxy curing agent in a mass ratio of 1:1, stirring evenly, and standing for 5 to 10 minutes to obtain epoxy resin coating; brushing the epoxy resin coating evenly on the concrete base 1; drying at room temperature to form a first epoxy resin coating 2 with a thickness of 0.1 mm on the concrete base 1; wherein the bonding strength of the first epoxy resin coating 2 to the concrete base 1 is greater than 2.5 MPa.

[0043] In order to ensure that the polyurea coating 3 can be firmly attached to the concrete base 1, a first epoxy resin coating 2 is provided between the polyurea coating 3 and the concrete base 1 to improve the waterproof performance and long-term durability of the coating. It can be understood by those skilled in the art that epoxy resin has excellent film-forming properties, its surface is flat and smooth, and it can react with the repair material, thereby improving the bonding strength between the coating and the concrete base 1. In a specific embodiment, the epoxy resin glue and the epoxy curing agent are first mixed in a mass ratio of 1:1, stirred evenly, and allowed to stand for 5 to 10 minutes to remove bubbles in the epoxy resin coating, and then the epoxy resin coating is evenly brushed on the concrete base 1. At room temperature, the epoxy resin glue and the epoxy curing agent in the epoxy resin coating gradually undergo a curing and cross-linking reaction, and a first epoxy resin coating 2 with a thickness of 0.1 mm is formed on the concrete base 1. In order to ensure that the first epoxy resin coating 2 has a strong bonding strength, it is necessary to use a special tester to perform a pull-out test. When the bonding strength of the first epoxy resin coating 2 to the concrete base 1 is greater than 2.5MPa, check whether the first epoxy resin coating 2 has defects such as missing coating, blistering, pinholes, etc. If there are defects, use epoxy resin repair putty to manually fill them to completely cover the concrete base 1. After the repair putty is cured and dry, the next stage of coating laying is carried out.

[0044] In some possible embodiments, spraying a polyurea coating 3 with a thickness of 1.0 mm on the first epoxy resin coating 2 includes: mixing a polyurea resin and an isocyanate curing agent in a mass ratio of 1:1, stirring evenly, to obtain a polyurea coating; spraying the polyurea coating on the first epoxy resin coating 2 for a first time to form a 0.5 mm polyurea initial coating on the first epoxy resin coating 2; after standing for 3 hours, spraying the polyurea coating on the polyurea initial coating for a second time to form a polyurea secondary coating on the polyurea initial coating, and the thickness of the polyurea coating 3 composed of the polyurea initial coating and the polyurea secondary coating is 1.0 mm; curing the polyurea coating 3, and the curing time exceeds 24 hours.

[0045] As a high-performance waterproof material, polyurea coating is sprayed twice to further improve the waterproofness of the immersed tube tunnel. First, the polyurea resin and the isocyanate curing agent are mixed in a mass ratio of 1:1, and after stirring evenly, the polyurea coating is obtained for standby use. The evenly mixed polyurea coating needs to be used within 30 to 60 minutes to ensure the best performance of the polyurea coating; then the first spraying is carried out, and the standby polyurea coating is evenly sprayed on the first epoxy resin coating 2 to form a polyurea initial coating with a thickness of 0.5 mm, and ensure that there is no omission and the thickness is uniform, keep the construction area clean, and avoid any form of touch or pollution; then, let it stand for 3 hours to allow the polyurea initial coating to begin to cure initially to form a stable substrate, and then In the second spraying, the polyurea coating is evenly sprayed on the polyurea initial coating to form a polyurea secondary coating. As time goes by, the polyurea secondary coating and the polyurea initial coating are combined with each other to completely cover the first epoxy resin coating 2, and the thickness of the polyurea coating 3 composed of the polyurea secondary coating and the polyurea initial coating is 1.0 mm; after the two sprayings, the surface of the coating is carefully checked. If there are defects such as pinholes and bubbles, they are repaired with a repair material compatible with the polyurea coating. When repairing, ensure that the repair area is flat and consistent with the polyurea coating 3 without obvious color difference; finally, the polyurea coating 3 is cured and maintained for more than 24 hours. During the maintenance period, water, oil, chemicals, etc. are prevented from directly contacting the polyurea coating 3, and the temperature and humidity of the construction area are controlled within a reasonable range.

[0046] In some possible implementations, after the first epoxy resin coating 2 is laid, the polyurea coating 3 is evenly sprayed on the first epoxy resin coating 2 within 4 to 24 hours.

[0047] Those skilled in the art can understand that the epoxy resin glue and epoxy curing agent in the first epoxy resin coating 2 gradually undergo a curing and cross-linking reaction. In order to maintain the adhesion of the first epoxy resin coating 2, the polyurea coating 3 needs to be sprayed within 4 to 24 hours. In the subsequent drying and curing, the first epoxy resin coating 2 and the polyurea coating 3 can be fully combined to improve the strength and stability of the coating.

[0048] In some possible implementations, after the second epoxy resin coating 4 is laid, the linen fiber cloth 5 is laid on the second epoxy resin coating 4 within 1 hour.

[0049] The flax fiber cloth 5 has high strength, good flexibility and tear resistance, and can effectively improve the overall mechanical properties of the coating, enabling it to resist impact from the outside of the immersed tube tunnel. The second epoxy resin coating 4 is also used as a binder to connect the polyurea coating 3 and the linen fiber cloth 5. When a second epoxy resin coating 4 is laid on the polyurea coating 3, the epoxy resin glue and epoxy curing agent in the second epoxy resin coating 4 can fully penetrate into the tiny pores of the fully cured polyurea coating 3. As time goes by, a stronger bonding interface is gradually formed. Within 1 hour after the second epoxy resin coating 4 is laid, the linen fiber cloth 5 is laid. At this time, the second epoxy resin coating 4 is in a semi-cured state and has excellent adhesion. The linen fiber cloth 5 is laid flat on the second epoxy resin coating 4. As time goes by, the remaining epoxy resin glue and epoxy curing agent in the second epoxy resin coating 4 continue to cross-link and cure. The second epoxy resin coating 4 gradually changes from liquid to solid, forming a strong chemical bond and mechanical lock with the linen fiber cloth 5, so that the linen fiber cloth 5 can be stably and reliably fixed on the second epoxy resin coating 4 and form a whole with the polyurea coating 3. In addition, during the laying process of the flax fiber cloth 5, bubbles and wrinkles should be avoided to ensure a close fit between the flax fiber cloth 5 and the second epoxy resin layer.

[0050] In some possible implementations, after the flax fiber cloth 5 is laid, the polyurethane coating 6 is evenly sprayed on the flax fiber cloth 5 24 hours later.

[0051] This is because, 24 hours after the flax fiber cloth 5 is laid, the second epoxy resin layer can be completely cured and fix the flax fiber cloth 5. The polyurethane coating is evenly sprayed on the flax fiber cloth 5, and after natural drying for 24 hours, a strong and durable polyurethane protective coating is formed on the flax fiber cloth 5. After drying, check whether the surface of the polyurethane coating 6 is flat and smooth, and whether there are defects such as unevenness, cracks, and peeling. If there are defects, use the same polyurethane coating to repair them, so that the repaired area and the polyurethane coating 6 are perfectly integrated. In addition, the thickness of the polyurethane coating 6 is controlled to 0.5mm to ensure that the polyurethane coating 6 is neither too thick to cause accumulation or flow, nor too thin to affect the protective effect.

[0052] Embodiment 2

[0053] The present invention provides a composite coating for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel. The composite coating is suitable for the method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel described in the first aspect, and is used to improve the waterproof and anti-permeability of a concrete base 1 on the immersed tube tunnel. The composite coating comprises: a first epoxy resin coating 2, the first epoxy resin coating 2 has a thickness of 0.1 mm, and is arranged on the concrete base 1; a polyurea coating 3, the polyurea coating 3 has a thickness of 1.0 mm, and is arranged on the first epoxy resin coating 2; a second epoxy resin coating 4, the second epoxy resin coating 4 has a thickness of 0.1 mm, and is arranged on the polyurea coating 3; a linen fiber cloth 5, which is arranged on the second epoxy resin coating 4; a polyurethane coating 6, the polyurethane coating 6 has a thickness of 0.5 mm, and is arranged on the linen fiber cloth 5; wherein the first epoxy resin coating 2 and the second epoxy resin coating 4 are the same.

[0054] In some possible implementations, the adhesion of the composite coating to the concrete base 1 is 4.5 MPa; and the anti-seepage pressure of the composite coating is greater than 1.6 MPa.

[0055] Specifically, the present invention provides a composite coating for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel, which is used to improve the waterproof and impermeability of a concrete base 1 on an immersed tube tunnel. The composite coating includes a first epoxy resin coating 2 with a thickness of 0.1 mm, a polyurea coating 3 with a thickness of 1.0 mm, a second epoxy resin coating 4 with a thickness of 0.1 mm, a linen fiber cloth 5, and a polyurethane coating 6 with a thickness of 0.5 mm, starting from the top of the concrete base 1. The composite coating is constructed according to the method described in the first aspect. After the construction is completed, the overall adhesion performance of the composite coating is tested using a pull-off adhesion tester. This test method can directly reflect the bonding strength between the composite coating and the concrete base 1, ensuring that the composite coating has sufficient stability and durability in practical applications. Finally, the adhesion of the composite coating on the concrete base 1 is measured to be 4.5 MPa, meeting the standard of adhesion>2.5 MPa.

[0056] Furthermore, the above composite coating was covered on the concrete test block to form a concrete specimen, and the anti-seepage performance of the concrete specimen was tested in accordance with the "Test Procedure for Hydraulic Concrete" (DL / T 5150-2017). The test parameters included: the test water pressure started from 0.1MPa, and 0.1MPa was added every 8 hours, and the pressure was increased step by step. As a result, when the maximum anti-seepage pressure reached 1.6Mpa, there was still no water seepage on the surface of the concrete specimen, which had good waterproof and anti-seepage performance. The composite coating can significantly improve the anti-seepage grade of concrete.

[0057] The present invention lays two waterproof layers of a concrete base layer 1 and a composite coating on the surface or at the connection between pipe sections and weak points of the immersed tube tunnel, so that the maximum anti-seepage pressure of the concrete base layer 1 and the composite coating is increased to 1.6 MPa, which significantly enhances the overall permeability of the immersed tube tunnel and ensures the safety and reliability of the immersed tube tunnel.

[0058] Since the second embodiment and the first embodiment are embodiments of the same inventive concept and some of their structures are exactly the same, the structures in the second embodiment that are substantially the same as those in the first embodiment will not be described in detail. For the parts not described in detail, please refer to the first embodiment.

[0059] Finally, it should be noted that the above embodiments are only specific implementations of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The protection scope of the present invention is not limited thereto. Although the present invention is described in detail with reference to the above embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above embodiments within the technical scope disclosed by the present invention, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention. They should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

[0060] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel, characterized in that: The method comprises the following steps: Inspect, clean and repair the concrete surface on the immersed tube tunnel to obtain a smooth concrete base; Laying a first epoxy resin coating with a thickness of 0.1 mm on the concrete base; Spraying a polyurea coating with a thickness of 1.0 mm on the first epoxy resin coating; Laying a second epoxy resin coating with a thickness of 0.1 mm on the polyurea coating; Laying a linen fiber cloth on the second epoxy resin coating; Spraying a polyurethane coating with a thickness of 0.5 mm on the linen fiber cloth; Wherein, the first epoxy resin coating and the second epoxy resin coating are the same.

2. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 1, characterized in that: The process of inspecting and cleaning the concrete surface on the immersed tube tunnel to obtain a concrete base with a smooth surface comprises the following steps: Conduct a comprehensive inspection of the concrete surface on the immersed tunnel to remove impurities and obtain the first clean surface of the concrete; Grinding the first clean concrete surface to obtain a flat second clean concrete surface; Deeply clean the second clean surface of the concrete by using a high-pressure water gun or a sandblasting device to obtain a third clean surface of the concrete that is free of oil, dust, and dry; The third clean surface of the concrete is repaired to obtain a concrete base with a smooth surface.

3. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 2 is characterized in that: The repairing of the third clean surface of the concrete specifically includes: Finding cracks, pores or pits on the third clean surface of the concrete to form a repair area; The repairing area is filled with repairing material, and after drying and curing, a concrete base with a flat surface and no depression is obtained.

4. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 3 is characterized in that: The step of laying a first epoxy resin coating having a thickness of 0.1 mm on the concrete base comprises: The epoxy resin glue and the epoxy curing agent are mixed in a mass ratio of 1:1, stirred evenly, and allowed to stand for 5 to 10 minutes to obtain an epoxy resin coating; Evenly brushing the epoxy resin coating on the concrete base; Drying at room temperature to form a first epoxy resin coating with a thickness of 0.1 mm on the concrete base; Wherein, the bonding strength of the first epoxy resin coating to the concrete base is greater than 2.5 MPa.

5. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 4 is characterized in that: The step of spraying a polyurea coating having a thickness of 1.0 mm on the first epoxy resin coating comprises: The polyurea resin and the isocyanate curing agent are mixed in a mass ratio of 1:1, and stirred evenly to obtain a polyurea coating; Spraying the polyurea coating on the first epoxy resin coating for the first time to form a polyurea initial coating with a thickness of 0.5 mm on the first epoxy resin coating; After standing for 3 hours, spraying the polyurea coating a second time on the polyurea primary coating to form a polyurea secondary coating on the polyurea primary coating, and the thickness of the polyurea coating composed of the polyurea primary coating and the polyurea secondary coating is 1.0 mm; The polyurea coating is cured for more than 24 hours.

6. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 1, characterized in that: After the first epoxy resin coating is laid, the polyurea coating is evenly sprayed on the first epoxy resin coating within 4 to 24 hours.

7. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 1, characterized in that: After the second epoxy resin coating is laid, the linen fiber cloth is laid on the second epoxy resin coating within 1 hour.

8. The method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 1, characterized in that: After the flax fiber cloth is laid, 24 hours later, the polyurethane coating is evenly sprayed on the flax fiber cloth.

9. A composite coating for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel, characterized in that: The composite coating is applicable to the method for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to any one of claims 1 to 8, and is used to improve the waterproof and impermeability of the concrete base on the immersed tube tunnel. The composite coating comprises: A first epoxy resin coating, the first epoxy resin coating has a thickness of 0.1 mm and is disposed on the concrete base; A polyurea coating having a thickness of 1.0 mm and disposed on the first epoxy resin coating; A second epoxy resin coating, the second epoxy resin coating has a thickness of 0.1 mm and is disposed on the polyurea coating; A linen fiber cloth is disposed on the second epoxy resin coating; A polyurethane coating having a thickness of 0.5 mm and disposed on the linen fiber cloth; Wherein, the first epoxy resin coating and the second epoxy resin coating are the same.

10. The composite coating for enhancing the waterproof performance of an ultra-wide section immersed tube tunnel according to claim 9, characterized in that: The adhesion of the composite coating to the concrete base is 4.5 MPa; the anti-seepage pressure of the composite coating is greater than 1.6 MPa.

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