Three-layer waterproof and heat preservation structure for cold region highway tunnel

Abstract

The utility model discloses a cold region highway tunnel three -layer waterproof heat preservation structure relates to the technical field of tunnel, including surface layer, bionic gradient heat preservation layer and self -repairing anti -permeation layer, the surface layer is the outermost layer, the bionic gradient heat preservation layer is the intermediate layer, the self -repairing anti -permeation layer is the inner layer, the bionic gradient heat preservation layer is by a plurality of heat preservation board splicing and is composed, through the synergies of surface layer, bionic gradient heat preservation layer and self -repairing anti -permeation layer, realized the integrated design of physical protection, efficient heat preservation and anti -permeation repair, the surface layer is as the outermost layer, through carbon fiber reinforced shotcrete, laser microtexturing honeycomb recess and reinforcing rib plate, effectively resist the physical damage and chemical corrosion of outside world, bionic gradient heat preservation layer utilizes the composite structure of polyurethane matrix and bionic hollow ceramic microsphere, combines gradient distribution design, and the heat transfer rate is reduced significantly.

Description

Technical Field

[0001] This utility model relates to the field of tunnel technology, specifically a three-layer waterproof and heat-insulating structure for highway tunnels in cold regions. Background Technology

[0002] Cold regions typically refer to areas with an average annual temperature below 0°C, characterized by long, cold winters that may be accompanied by extreme weather events such as blizzards and hail. These conditions pose challenges to tunnel construction and long-term operation. Seasonally or perennially frozen soil is widespread in cold regions. Frozen soil expands when it freezes and sinks when it thaws, leading to uneven stress on the tunnel structure and potentially causing problems such as lining cracking and water leakage. To prevent icing inside the tunnel, insulation measures are necessary, such as installing insulation layers and heating systems, to ensure traffic safety and normal equipment operation. Low winter temperatures slow concrete setting and increase the brittleness of steel, reducing construction efficiency. Key construction processes usually need to be completed within the short summer window. Highway tunnels in cold regions are crucial projects for extending highway networks to higher latitudes and altitudes; technological breakthroughs in these tunnels are of great significance for promoting regional economic development and strengthening international connectivity. With the development of materials science and engineering technology, the construction of tunnels in cold regions will become more efficient and reliable.

[0003] Extensive research revealed problems with existing tunnel insulation and waterproofing structures. Due to the low temperatures in cold regions, the thermal insulation performance of a single-material insulation layer can drastically decrease, leading to cracking of the concrete layer and subsequent tunnel leakage. Therefore, based on the aforementioned research and existing technologies, a three-layer waterproofing and insulation structure for highway tunnels in cold regions is proposed to address these issues. Utility Model Content

[0004] The purpose of this invention is to provide a three-layer waterproof and heat-insulating structure for highway tunnels in cold regions, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A three-layer waterproof and thermal insulation structure for highway tunnels in cold regions includes: an outermost layer, a biomimetic gradient insulation layer, and a self-healing seepage-proof layer. The outermost layer is the surface layer, the biomimetic gradient insulation layer is the middle layer, and the self-healing seepage-proof layer is the inner layer. The biomimetic gradient insulation layer is composed of several insulation boards spliced ​​together. Each insulation board is a composite board made of a polyurethane matrix and uniformly distributed biomimetic hollow ceramic microspheres. The diameter of the biomimetic hollow ceramic microspheres is 0.5-2 mm, and the volume percentage of the biomimetic hollow ceramic microspheres is 30%-50%. The outer shell of the biomimetic hollow ceramic microspheres is silicon nitride ceramic, and the interior is filled with nitrogen gas. A conductive heating wire is fixedly installed on the bottom surface of each insulation board, and conductive tape is fixedly installed at the joints of the bottom surfaces of several insulation boards.

[0007] Furthermore, the surface layer includes a shotcrete layer, the top surface of which is laser-microtextured to form multiple honeycomb grooves with a depth of 20-50 μm. The bottom surface of the shotcrete layer is coated with polyurethane adhesive containing 0.5 wt% graphene to form a nano-stacking structure. Several reinforcing ribs for reinforcement are fixedly installed on the top surface of the shotcrete layer. The shotcrete layer is reinforced with carbon fiber and has a thickness error of ≤5 mm.

[0008] Furthermore, a shape memory alloy fiber mesh is laid between the sprayed concrete layer and several insulation boards. The shape memory alloy fiber mesh has a diameter of 0.1 mm and a spacing of 10 mm. Several support and reinforcement grooves are opened on the top surface of the sprayed concrete layer. Strong support ribs for enhancing rigidity are fixedly installed inside the support and reinforcement grooves.

[0009] Furthermore, the self-healing seepage-proof layer comprises microencapsulated epoxy resin modified concrete and polyurea waterproof coating. The polyurea waterproof coating is applied to the bottom surface of the microencapsulated epoxy resin modified concrete. The microcapsules in the microencapsulated epoxy resin modified concrete have a diameter of 50-100 μm and a content of 5%-8%, and contain DCPD monomer healing agent. Several fiber optic sensors are embedded in the microencapsulated epoxy resin modified concrete, and the distance between the fiber optic sensors is 2m.

[0010] Furthermore, two plug-in blocks are fixedly installed on both sides of the insulation board, and plug-in slots are opened on the other two sides of the insulation board. The plug-in blocks are movably engaged with the plug-in slots. A rivet is connected through the inside of the plug-in slot. The rivet passes through the plug-in block and is used to fasten multiple insulation boards. The insulation board has a size of 600mm×1200mm and a thickness error of ≤0.5mm.

[0011] Furthermore, several temperature and humidity composite sensors are fixedly installed on the bottom surface of the microencapsulated epoxy resin modified concrete.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. Through the synergistic effect of the surface layer, the biomimetic gradient insulation layer, and the self-healing waterproof layer, an integrated design of physical protection, efficient insulation, and waterproofing is achieved. The surface layer, as the outermost layer, effectively resists external physical damage and chemical erosion through carbon fiber reinforced shotcrete, laser-textured honeycomb grooves, and reinforcing ribs. The biomimetic gradient insulation layer utilizes a composite structure of polyurethane matrix and biomimetic hollow ceramic microspheres, combined with a gradient distribution design, to significantly reduce the heat transfer rate. The inner self-healing waterproof layer achieves self-repair of cracks and long-term stability of waterproofing performance through the dual barriers of microencapsulated epoxy resin modified concrete and polyurea waterproof coating. The three layers complement each other, forming a closed-loop system of "protection-insulation-waterproofing." Attached Figure Description

[0014] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0015] Figure 2 This is a schematic diagram of the connection structure between the support reinforcement groove and the strong support rib of this utility model.

[0016] Figure 3 This is a bottom view of the connection structure of the biomimetic gradient insulation layer and the biomimetic gradient insulation layer of this utility model.

[0017] Figure 4 This is a schematic diagram of the connection structure between the plug block and the plug slot of this utility model;

[0018] Figure 5 This is a bottom view schematic diagram of the microencapsulated epoxy resin modified concrete structure of this utility model.

[0019] In the diagram: 1. Surface layer; 2. Bionic gradient insulation layer; 3. Self-healing seepage-proof layer; 4. Shotcrete layer; 5. Support and reinforcement groove; 6. Strong support rib; 7. Reinforcing rib; 8. Honeycomb groove; 9. Polyurethane adhesive; 10. Shape memory alloy fiber mesh; 11. Insulation board; 12. Conductive heating wire; 13. Connecting block; 14. Connecting groove; 15. Rivet; 16. Conductive tape; 17. Microencapsulated epoxy resin modified concrete; 18. Polyurea waterproof coating; 19. Temperature and humidity composite sensor; 20. Fiber optic sensor. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] In one typical implementation of this application, please refer to Figures 1-5 A three-layer waterproof and thermal insulation structure for highway tunnels in cold regions includes: an outermost layer 1, a biomimetic gradient insulation layer 2, and a self-healing seepage-proof layer 3. The outermost layer is the surface layer, the middle layer is the biomimetic gradient insulation layer 2, and the inner layer is the self-healing seepage-proof layer 3. The biomimetic gradient insulation layer 2 is composed of several insulation boards 11 spliced ​​together. The insulation board 11 is a composite board made of polyurethane matrix and uniformly distributed biomimetic hollow ceramic microspheres. The diameter of the biomimetic hollow ceramic microspheres is 0.5-2mm, and the volume ratio of the biomimetic hollow ceramic microspheres is 30%-50%. The outer shell of the biomimetic hollow ceramic microspheres is silicon nitride ceramic and the inside is filled with nitrogen gas. The biomimetic hollow ceramic microspheres are distributed in a gradient, with the upper layer of biomimetic hollow ceramic microspheres being larger than the lower layer. The larger microspheres in the upper layer can better block heat loss upwards because the larger microspheres have a relatively higher nitrogen content inside, resulting in a stronger thermal insulation effect. The smaller microspheres in the lower layer can also play a certain role in thermal insulation while ensuring structural stability and uniformity. This gradient distribution achieves more effective heat blocking in the vertical direction, improving the overall heat preservation efficiency. The bottom surface of the insulation board 11 is fixedly installed with a conductive heating wire 12, and conductive tape 16 is fixedly installed at the joints of the bottom surfaces of several insulation boards 11.

[0022] In cold environments, the conductive heating wire 12 can play a role in preventing structural performance from deteriorating due to low temperatures. The self-healing waterproof layer 3 can also maintain a certain degree of flexibility at low temperatures to ensure that the waterproof function is not affected. The surface layer 1 and the self-healing waterproof layer 3 can effectively resist the erosion of various chemical substances.

[0023] Preferably, the insulation board 11 in the biomimetic gradient insulation layer 2 is a composite board made of polyurethane matrix and biomimetic hollow ceramic microspheres. The polyurethane matrix itself has good thermal insulation performance and can effectively reduce heat conduction, while the outer shell of the biomimetic hollow ceramic microspheres is silicon nitride ceramic and the interior is filled with nitrogen gas. Nitrogen gas is an inert gas with extremely low thermal conductivity, and the silicon nitride ceramic shell can effectively block heat transfer. The combination of the two makes the biomimetic hollow ceramic microspheres an excellent thermal insulation unit, which greatly reduces the heat transfer rate through the insulation layer and optimizes the thermal insulation through gradient distribution.

[0024] The self-healing geomembrane layer 3, as the inner layer, can tightly adhere to the internal structure, forming a reliable seepage barrier. It can prevent internal materials from leaking into the external environment. The entire structure consists of the outermost layer 1, the biomimetic gradient insulation layer 2, and the self-healing geomembrane layer 3. Each layer has a clear location and function. The outermost layer 1 can resist external physical damage and chemical erosion, providing protection for the internal structure; the middle biomimetic gradient insulation layer 2 achieves efficient heat preservation; and the inner self-healing geomembrane layer 3 ensures seepage prevention performance.

[0025] The surface layer 1 includes a shotcrete layer 4. The top surface of the shotcrete layer 4 is laser-microtextured to form multiple honeycomb grooves 8 with a depth of 20-50 μm. The bottom surface of the shotcrete layer 4 is coated with polyurethane adhesive 9, which contains 0.5 wt% graphene to form a nano-stacking structure. Several reinforcing ribs 7 are fixedly installed on the top surface of the shotcrete layer 4 for reinforcement. The shotcrete layer 4 is reinforced with carbon fiber and has a thickness error of ≤5 mm.

[0026] Preferably, the shotcrete layer 4 is reinforced with carbon fiber, which has high strength and high modulus. Incorporating it into the shotcrete can effectively improve the tensile, compressive and flexural strength of the concrete layer. The reinforcing ribs 7 can disperse and transfer the load, distributing the concentrated force evenly over a larger area and effectively reducing local stress concentration.

[0027] The honeycomb grooves 8 increase the roughness and specific surface area of ​​the shotcrete layer 4, providing better adhesion for subsequent bonding with other materials or structures. The polyurethane adhesive 9 on the bottom surface of the shotcrete layer 4 contains 0.5 wt% graphene. Graphene has excellent mechanical and electrical properties. When added to the polyurethane adhesive 9, it can form a nanoscale pinning structure, enhancing the interfacial bonding force between the adhesive and the shotcrete layer 4.

[0028] A shape memory alloy fiber mesh 10 is laid between the shotcrete layer 4 and several insulation boards 11. The shape memory alloy fiber mesh 10 has a diameter of 0.1 mm, a spacing of 10 mm, a pre-tension strain of 3%, and low-temperature triggered shrinkage. Several support and reinforcement grooves 5 are opened on the top surface of the shotcrete layer 4. Strong support ribs 6 for enhancing rigidity are fixedly installed inside the support and reinforcement grooves 5.

[0029] Preferably, the shape memory alloy fiber mesh 10 shrinks at low temperatures, actively offsetting the cold shrinkage stress of concrete, reducing temperature cracks, and supporting the reinforcement groove 5 + strong support bar 6 to form an "embedded skeleton", thereby improving the local bending stiffness of the sprayed concrete layer 4 and avoiding the deformation of the biomimetic gradient insulation layer 2 under pressure.

[0030] The self-healing waterproof layer 3 includes microencapsulated epoxy resin modified concrete 17 and polyurea waterproof coating 18. The polyurea waterproof coating 18 is applied to the bottom surface of the microencapsulated epoxy resin modified concrete 17. The microencapsulated epoxy resin modified concrete 17 not only has a self-healing function, but also improves the strength, toughness and durability of the concrete through the modification of epoxy resin. The presence of microcapsules has little impact on the mechanical properties of the concrete, ensuring that the concrete maintains good load-bearing capacity before and after self-healing. The microcapsules in the microencapsulated epoxy resin modified concrete 17 have a diameter of 50-100μm and a content of 5% to 8%, and contain DCPD monomer healing agent. Several fiber optic sensors 20 are embedded in the microencapsulated epoxy resin modified concrete 17, and the distance between the fiber optic sensors 20 is 2m.

[0031] Preferably, in the microencapsulated epoxy resin modified concrete 17, when cracks appear in the concrete, the stress concentration at the crack tip causes the microcapsules to rupture, releasing the internal DCPD monomer healing agent. The DCPD monomer reacts with the catalyst in the concrete, achieving automatic filling and repair of the cracks. The polyurea waterproof coating 18 forms an additional waterproof barrier on the bottom surface of the microencapsulated epoxy resin modified concrete 17. Polyurea has excellent waterproof performance, chemical corrosion resistance, and abrasion resistance, and can adhere tightly to the concrete surface, preventing moisture from penetrating into the concrete from the bottom. It works synergistically with the self-healing function of the microencapsulated epoxy resin modified concrete 17 to provide double protection for the self-healing seepage-proof layer 3, further enhancing the overall seepage-proof effect.

[0032] Multiple fiber optic sensors 20 in the microencapsulated epoxy resin modified concrete 17 form a dense monitoring network. The fiber optic sensors 20 can sense changes in parameters such as stress, strain, and temperature inside the concrete in real time. By monitoring these parameters, potential cracks and damage in the concrete can be detected in time, and warnings can be issued even before the cracks have significantly expanded.

[0033] Two plug-in blocks 13 are fixedly installed on both sides of the insulation board 11. Plug-in slots 14 are provided on the other two sides of the insulation board 11. The plug-in blocks 13 are movably engaged with the plug-in slots 14. Rivets 15 are connected through the interior of the plug-in slots 14, passing through the plug-in blocks 13. The rivets 15 are used to fasten multiple insulation boards 11. The insulation board 11 has dimensions of 600mm × 1200mm and a thickness error of ≤0.5mm.

[0034] Preferably, the interlocking blocks 13 and interlocking slots 14 on both sides of the insulation board 11 enable quick and accurate alignment during splicing, greatly improving splicing efficiency. Construction workers do not need complex positioning and adjustment operations; they only need to insert the interlocking blocks 13 into the corresponding interlocking slots 14 to complete the initial splicing, saving construction time and labor costs. The rivets 15 effectively prevent loosening or displacement of the insulation board 11 after splicing. Even under external forces such as wind and vibration, the connection between multiple insulation boards 11 remains firm, ensuring the overall stability of the insulation system.

[0035] Several temperature and humidity composite sensors 19 are fixedly installed on the bottom surface of the microencapsulated epoxy resin modified concrete 17, and a prefabricated LoRa module is installed in the tunnel.

[0036] Preferably, the temperature and humidity composite sensor 19 is configured to monitor the temperature and humidity changes inside and around the concrete in real time and accurately, capturing minute temperature and humidity fluctuations, providing detailed and accurate data support for the safety assessment of the tunnel structure. The LoRa module has the characteristics of low power consumption and long-distance transmission, which can quickly and stably transmit the data collected by the temperature and humidity composite sensor 19 to the monitoring center. Once the temperature and humidity composite sensor 19 detects that the temperature and humidity exceed the preset safety range, the LoRa module can immediately send the warning information to the relevant management personnel so that they can take timely measures.

[0037] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A three-layer waterproof and heat-insulating structure for highway tunnels in cold regions, characterized in that, include: The structure consists of an outermost layer (1), a biomimetic gradient insulation layer (2), and a self-healing seepage-proof layer (3). The outermost layer (1), the middle layer (2), and the inner layer (3) are all constructed from a series of insulation boards (11). The insulation board (11) is a composite board made of polyurethane matrix and uniformly distributed biomimetic hollow ceramic microspheres. The diameter of the biomimetic hollow ceramic microspheres is 0.5-2 mm, and the volume ratio of the biomimetic hollow ceramic microspheres is 30%-50%. The outer shell of the biomimetic hollow ceramic microspheres is silicon nitride ceramic and the interior is filled with nitrogen gas. A conductive heating wire (12) is fixedly installed on the bottom surface of the insulation board (11), and conductive tape (16) is fixedly installed at the joints of the bottom surfaces of the insulation boards (11).

2. The three-layer waterproof and heat-insulating structure for highway tunnels in cold regions according to claim 1, characterized in that: The surface layer (1) includes a shotcrete layer (4). The top surface of the shotcrete layer (4) is laser microtextured to form multiple honeycomb grooves (8). The depth of the honeycomb grooves (8) is 20-50 μm. The bottom surface of the shotcrete layer (4) is sprayed with polyurethane adhesive (9). The polyurethane adhesive (9) contains 0.5 wt% graphene to form a nano-stacking structure. Several reinforcing ribs (7) for reinforcement are fixedly installed on the top surface of the shotcrete layer (4). The shotcrete layer (4) is reinforced with carbon fiber and has a thickness error of ≤5 mm.

3. The three-layer waterproof and heat-insulating structure for highway tunnels in cold regions according to claim 2, characterized in that: A shape memory alloy fiber mesh (10) is laid between the sprayed concrete layer (4) and several insulation boards (11). The shape memory alloy fiber mesh (10) has a diameter of 0.1 mm and a spacing of 10 mm. Several support and reinforcement grooves (5) are opened on the top surface of the sprayed concrete layer (4). Strong support ribs (6) for enhancing rigidity are fixedly installed inside the support and reinforcement grooves (5).

4. The three-layer waterproof and heat-insulating structure for highway tunnels in cold regions according to claim 1, characterized in that: The self-healing waterproof layer (3) includes microencapsulated epoxy resin modified concrete (17) and polyurea waterproof coating (18). The polyurea waterproof coating (18) is coated on the bottom surface of the microencapsulated epoxy resin modified concrete (17). The microcapsules in the microencapsulated epoxy resin modified concrete (17) have a diameter of 50-100μm and a content of 5% to 8%, and contain DCPD monomer healing agent. Several fiber optic sensors (20) are embedded in the microencapsulated epoxy resin modified concrete (17), and the distance between the several fiber optic sensors (20) is 2m.

5. The three-layer waterproof and heat-insulating structure for highway tunnels in cold regions according to claim 1, characterized in that: Two plug-in blocks (13) are fixedly installed on both sides of the insulation board (11), and plug-in slots (14) are opened on the other two sides of the insulation board (11). The plug-in blocks (13) are movably engaged with the plug-in slots (14). A rivet (15) is connected through the inside of the plug-in slot (14). The rivet (15) passes through the plug-in block (13) and is used to fasten multiple insulation boards (11). The insulation board (11) has a size of 600mm×1200mm and a thickness error of ≤0.5mm.

6. The three-layer waterproof and heat-insulating structure for highway tunnels in cold regions according to claim 4, characterized in that: Several temperature and humidity composite sensors (19) are fixedly installed on the bottom surface of the microencapsulated epoxy resin modified concrete (17).

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