Construction method of high-geothermal-tunnel aerogel heat insulation waterproof felt tunnel structure

Abstract

The application relates to a construction method of a high-geothermal-tunnel aerogel heat-insulation waterproof felt tunnel structure, in which geotextile is fixed on concrete on a tunnel primary support sprayed concrete through steel nails with fixed intervals, the upper end of self-adhesive aerogel heat-insulation waterproof felt is fixed on the top end of the geotextile, a row of steel nails with equal intervals are used for fixing, the self-adhesive aerogel heat-insulation waterproof felt is pasted on the geotextile through self-adhesive tape, finally, concrete is poured on the outside to form a concrete lining, and the construction is completed. The method makes the steel nails located on the outside of the aerogel heat-insulation waterproof felt, effectively reduces the influence of the metal on the heat conductivity coefficient, improves the heat-insulation effect, simultaneously reduces the construction difficulty, the tunnel structure obtained through the construction has the advantages of good heat-insulation effect, high installation efficiency, environment-friendly and non-combustion materials, is convenient to install and use, and the problems of heat-insulation performance attenuation of the materials in the service process, reduction of the heat preservation effect or the construction effect are avoided.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction, specifically relating to a construction method for a high geothermal tunnel aerogel thermal insulation and waterproof felt tunnel structure. Background Technology

[0002] With the rapid development of my country's economy, infrastructure projects, represented by railways and highways, are also developing rapidly. Tunnel construction typically involves first initially supporting the rock face with shotcrete, then hanging geotextile, followed by laying waterproofing membranes, then insulation boards, then more waterproofing membranes, and finally lining with concrete. However, the construction environment inside high-temperature geothermal tunnels is harsh, with high-temperature water and rock adversely affecting the construction process. The main problems include: traditional insulation materials may experience a decrease in thermal conductivity due to tunnel pressure, reducing their insulation effect and affecting the service life of the structure; organic insulation materials are more prone to ignition in high-temperature environments, potentially causing fires; the laying method is cumbersome and the construction operation is difficult; and high-temperature environments significantly reduce the long-term service life of organic insulation materials.

[0003] In view of this, there is a need to invent a construction method suitable for high geothermal tunnel structures. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects in the existing technology and provide a construction method for a high geothermal tunnel aerogel thermal insulation and waterproof felt tunnel structure with good thermal insulation and waterproof effect, safe construction and ideal service capability.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A construction method for a geothermal tunnel aerogel thermal insulation and waterproof felt tunnel structure includes the following steps:

[0007] S1: First, spray concrete is applied to the tunnel rock wall. After the concrete solidifies, an initial support spray concrete layer is formed.

[0008] S2: Use steel nails to nail the geotextile to the shotcrete to form the first geotextile layer;

[0009] S3: Fix the top of the self-adhesive aerogel thermal insulation and waterproofing felt to the initial support sprayed concrete layer and the first geotextile layer using a row of steel nails. Let the self-adhesive aerogel thermal insulation and waterproofing felt hang down naturally. Then, gradually bond the self-adhesive aerogel thermal insulation and waterproofing felt to the first geotextile layer from top to bottom to form a self-adhesive aerogel felt layer.

[0010] S4: The self-adhesive aerogel felt layer formed in step S3 is then lined with concrete. Construction is completed after the concrete has solidified.

[0011] As a further improvement of the present invention, the self-adhesive aerogel thermal insulation and waterproof felt layer consists of, from the inside out, a self-adhesive tape, a high-temperature waterproof and breathable membrane, a silica aerogel layer, a second geotextile layer, and a self-adhesive waterproof board. The self-adhesive tape, the high-temperature waterproof and breathable membrane, the silica aerogel layer, and the second geotextile layer are fixed by sewing together with plastic thread, and the self-adhesive waterproof board is bonded and fixed to the second geotextile layer.

[0012] As a further improvement of the present invention, the self-adhesive aerogel thermal insulation and waterproof felt is prepared by the following method: First, two geotextiles with a width of 2m are placed side by side to form a second geotextile layer 4-4; four silica aerogels with a width of 1.0m are placed side by side inside the second geotextile layer to form a silica aerogel layer 4-3; a TPU high-temperature waterproof and breathable membrane block with a width of 4m is placed inside the silica aerogel layer; twelve universal self-adhesive tapes with a width of 80mm are arranged in groups of three, with a center-to-center distance of 50cm between the universal self-adhesive tapes in each group, and the position of each aerogel corresponds to one group, with the middle self-adhesive tape corresponding to the center of the aerogel; the layers are sewn together with plastic thread; and a self-adhesive waterproof board 4-5 with a width of 4m is placed on the outermost layer and bonded to the second geotextile layer 4-4.

[0013] As a further improvement of the present invention, the transverse stitching span of the plastic thread is 60mm, and the threading position is about 10mm away from the edge of the self-adhesive tape. For every 1 meter of stitching length (referring to the length of the waterproof felt), the plastic thread needs to be cut and re-sewed to avoid the waterproof felt falling off during assembly due to thread detachment.

[0014] As a further improvement of the present invention, the silica aerogel is a general-purpose silica aerogel with a thickness of 8 mm, a thermal conductivity of less than 0.02 W / (m·K), a porosity of 80%-99.8%, and a specific surface area of ​​200-1000 m². 2 / g, density approximately 0.03g / cm³ 3 .

[0015] As a further improvement of the present invention, the thickness of the self-adhesive waterproof membrane is 1.0-1.5mm, and the VA content is 5.0%-5.5%.

[0016] As a further improvement of the present invention, the self-adhesive tape has a thickness of 0.1 mm; the high-temperature waterproof and breathable membrane is made of TPU material; and the plastic wire is made of polytetrafluoroethylene with a diameter of 2.3 mm.

[0017] As a further improvement of the present invention, the vertical and horizontal spacing of the steel nails in step S2 is 50cm, and the spacing of the steel nails in step S3 is 50cm.

[0018] The beneficial effects of adopting the above technical solution are as follows:

[0019] The construction method for the self-adhesive aerogel thermal insulation and waterproof felt tunnel structure provided by this invention, except that the top of the self-adhesive aerogel thermal insulation and waterproof felt is fixed with steel nails, the other steel nails are located on the outside of the aerogel thermal insulation and waterproof felt, which effectively reduces the influence of metal on the thermal conductivity, improves the thermal insulation effect, and reduces the construction difficulty.

[0020] The construction method provided by this invention applies self-adhesive aerogel thermal insulation and waterproofing felt to tunnels in high and low heat zones, effectively isolating the high temperature of the rock wall and avoiding the impact of sprayed high-temperature water on the tunnel construction process and the long-term use of track facilities.

[0021] The tunnel structure obtained by the method provided by the present invention has the advantages of good heat insulation effect, high installation efficiency, environmentally friendly and non-combustible materials, convenient installation and use, and avoids the problems of heat insulation performance degradation, heat preservation effect or construction effect reduction of materials during service.

[0022] The aerogel thermal insulation and waterproof felt used in this invention has the advantages of good thermal insulation effect, high installation efficiency, environmentally friendly and non-flammable material, and convenient installation and use, avoiding the problems of material performance degradation, reduced thermal insulation effect or construction effect during service. Attached Figure Description

[0023] Figure 1 This invention relates to an aerogel thermal insulation and waterproof felt high geothermal tunnel structure;

[0024] Figure 2 This invention relates to a self-adhesive aerogel thermal insulation and waterproof felt structure.

[0025] Figure 3 This is another structural view of the self-adhesive aerogel thermal insulation and waterproof felt structure of the present invention;

[0026] In the attached diagram: 1. Tunnel wall, 2. Initial support shotcrete layer, 3. First geotextile layer, 4. Self-adhesive aerogel thermal insulation and waterproof felt layer, 5. Lining concrete layer, 4-1. Self-adhesive tape, 4-2. High-temperature waterproof and breathable membrane, 4-3. Silica aerogel layer, 4-4. Second geotextile layer, 4-5. Self-adhesive waterproof membrane, 4-6. Plastic line. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the invention will be described clearly and completely below in conjunction with specific embodiments.

[0028] Unless otherwise specified, the methods and operations used in this embodiment are standard industry practices, such as the composition and spraying of concrete. The materials used in this embodiment are conventional and commercially available: the self-adhesive tape is a general-purpose self-adhesive tape, 80mm wide and 0.1mm thick (model: TJZJD-II). The high-temperature waterproof and breathable membrane used is a standard high-temperature waterproof and breathable membrane made of TPU (model: TPU transparent film). The silica aerogel has a thermal conductivity of less than 0.02 W / (m·K), a porosity of 80%-99.8%, and a specific surface area of ​​200-1000 m². 2 / g, density approximately 0.03g / cm³ 3 Thickness 8mm (model: high temperature resistant silica aerogel felt); plastic thread material is polytetrafluoroethylene (model: polytetrafluoroethylene 1250D high temperature resistant sewing thread), diameter is 2.3mm; self-adhesive waterproof board (model: EVA-ZB-FZR-25m×4m×1.5mm or EVA-ZB-FZR-25m×4m×1.0mm) thickness is 1.0-1.5mm, VA content 5.0%-5.5%.

[0029] Example 1: Construction Method of Aerogel Thermal Insulation and Waterproofing Felt for High Geothermal Tunnels

[0030] Aerogel thermal insulation and waterproof felt high geothermal tunnel structure, such as Figure 1 As shown, from the tunnel rock wall inwards, the layers are: tunnel rock wall 1, initial support shotcrete layer 2, first geotextile layer 3, self-adhesive aerogel thermal insulation and waterproof felt layer 4, and lining concrete layer 5. The first geotextile layer 3 is fixed to the initial support shotcrete layer 2 with steel nails. The self-adhesive aerogel thermal insulation and waterproof felt layer 4 is bonded and fixed to the first geotextile layer 3. For reinforcement, the top of the self-adhesive aerogel thermal insulation and waterproof felt layer 4 is fixed to the first geotextile layer 3 and the initial support shotcrete layer 2 with a row of steel nails.

[0031] The construction steps are as follows:

[0032] S1: First, spray concrete is applied to the tunnel rock wall. After the concrete solidifies, an initial support spray concrete layer is formed. The initial support spray concrete is used to fill and level uneven areas of the rock wall, and also facilitates the subsequent installation of geotextile. Before proceeding to the next step of construction, the dust and dirt on the concrete surface should be cleaned.

[0033] S2: The first geotextile layer should be hung tightly against the surface of the initial support shotcrete and fixed with steel nails. The geotextile should be laid as flat as possible so that the formed geotextile is flat and tightly attached, and to prevent the accumulation of geotextile wrinkles from creating artificial water storage points.

[0034] S3: The aerogel thermal insulation and waterproofing felt is laid from the top to the side walls, suspended. The top of the self-adhesive aerogel thermal insulation and waterproofing felt is fixed to the initial sprayed concrete layer and the first geotextile layer with a row of steel nails. The self-adhesive aerogel thermal insulation and waterproofing felt hangs down naturally. Then, from top to bottom, the self-adhesive aerogel thermal insulation and waterproofing felt is gradually pressed and bonded to the first geotextile layer to ensure the bonding effect. Multiple aerogel thermal insulation and waterproofing felts are tightly fitted together to reduce gaps and ensure the effect.

[0035] S4: The self-adhesive aerogel felt layer formed in step S3 is then lined with concrete. Construction is completed after the concrete has solidified.

[0036] The structure of the self-adhesive aerogel thermal insulation and waterproof felt used is as follows: Figure 2 From the inside out, the structure consists of self-adhesive tape 4-1, high-temperature waterproof and breathable membrane 4-2, silica aerogel layer 4-3, second geotextile layer 4-4, and self-adhesive waterproof board 4-5. The self-adhesive tape 4-1, high-temperature waterproof and breathable membrane 4-2, silica aerogel layer 4-3, and second geotextile layer 4-4 are sewn together and fixed by plastic thread 4-6. The self-adhesive waterproof board 4-5 is bonded and fixed to the second geotextile layer 4-4.

[0037] It is made using the following method:

[0038] Step 1: Material Preparation

[0039] First, prepare a 4m wide self-adhesive waterproof board 4-5 and place it as the outermost layer.

[0040] Two geotextile sheets, each 2m wide, are placed side by side to form a second geotextile layer 4-4; four silica aerogel sheets, each 1.0m wide, are placed side by side inside the second geotextile layer to form a silica aerogel layer 4-3.

[0041] A 4m wide high-temperature waterproof and breathable membrane block is placed inside the silica aerogel layer. The high-temperature waterproof and breathable membrane can effectively prevent water seepage in the tunnel from filling the gaps in the aerogel and ensure the thermal insulation effect of the aerogel.

[0042] Prepare 12 strips of general-purpose self-adhesive tape, each 80mm wide. Group them into sets of three, with a center-to-center distance of 50cm between the tapes in each set. Each aerogel piece corresponds to one set, with the center tape aligned with the center of the silica aerogel block. The non-adhesive side should contact the high-temperature waterproof and breathable membrane. See [link / details]. Figure 3 As shown.

[0043] Step 2: Fix

[0044] Thread a needle through the outer side of the second geotextile layer, with the plastic thread joint located on the outer side of the second geotextile. Using a transverse sewing method, tightly sew the second geotextile layer 4-4, silica aerogel layer 4-3, high-temperature waterproof and breathable membrane 4-2, and self-adhesive tape 4-1 together layer by layer. The transverse sewing span of the plastic thread is 60mm, and the thread insertion point is approximately 10mm from the edge of the self-adhesive tape. For every 1 meter of sewn length (referring to the length of the waterproof felt), the plastic thread needs to be cut and re-sewed to prevent unraveling and subsequent detachment of the waterproof felt during assembly. After sewing is complete, adhere and fix the self-adhesive waterproof board to the second geotextile layer.

[0045] Comparative Example 1: Aerogel thermal insulation and waterproof felt, without the use of a high-temperature waterproof and breathable membrane.

[0046] The tunnel structure, from the outside to the inside, consists of the tunnel rock wall, the initial support shotcrete layer, the first geotextile layer, the self-adhesive aerogel thermal insulation and waterproof felt layer, and the lining concrete layer.

[0047] The construction method is the same as that of the above-mentioned aerogel thermal insulation and waterproof felt (using a high-temperature waterproof and breathable membrane).

[0048] In this method, there is no waterproof structure between the aerogel and the tunnel wall during the use of waterproof felt. Water seeping from the tunnel wall penetrates the initial support sprayed concrete layer and the first geotextile layer, and then enters the silica aerogel, filling the pores of the aerogel, destroying the silica aerogel structure, and causing a significant decrease in the thermal insulation effect.

[0049] Comparative Example 2 uses a double-layer board + insulation board.

[0050] The tunnel structure, from the outside to the inside, consists of tunnel walls, initial support shotcrete, geotextile, waterproofing membrane, insulation board, waterproofing membrane again, and lining concrete.

[0051] The construction method is as follows: The geotextile is fixed to the initial shotcrete layer using steel nails and hot-melt washers; then, an electric hot-melt machine is used to heat and melt the first waterproofing membrane and the hot-melt washers, thus bonding them together; polyurethane adhesive is applied to the surface of the first waterproofing membrane and the insulation board, and after the adhesive begins to gel, the insulation board is attached to the surface of the first waterproofing membrane and pressed tightly by hand until sufficient bonding strength is achieved; then, urethane adhesive is applied to the other side of the insulation board and the surface of the second waterproofing membrane, and the second waterproofing membrane is bonded to the insulation board using the same method; finally, lining concrete is poured on the surface of the outermost waterproofing membrane to form the lining concrete layer, completing the construction.

[0052] This method is prone to problems during construction, such as the adhesive boards easily falling off, uneven board laying, and large gaps between boards, with the gaps widening towards the arch. This can significantly reduce the insulation effect. In addition, this method also has the problems of low construction efficiency and high manual workload.

[0053] Comparative Example 3: Polyurethane spraying material + waterproof membrane

[0054] The tunnel structure, from the outside to the inside, consists of tunnel walls, initial support shotcrete, geotextile, self-adhesive waterproof membrane, sprayed polyurethane foam, and lining concrete.

[0055] The geotextile is fixed to the initial support shotcrete layer by steel nails; a self-adhesive waterproof membrane is attached to the surface of the geotextile; a sprayed polyurethane insulation material for cold-region tunnels is sprayed onto the surface of the self-adhesive waterproof membrane to form a sprayed polyurethane foam layer; and lining concrete is poured on the surface of the sprayed polyurethane foam layer to form a lining concrete layer.

[0056] This method offers a simpler construction approach compared to Comparative Example 1, with higher material adhesion and better insulation. However, polyurethane materials are somewhat toxic, their foaming density is difficult to control under high-temperature conditions, resulting in significant thickness fluctuations. Furthermore, they are flammable and prone to posing construction safety risks.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A construction method of a high-geothermal-tunnel aerogel thermal insulation waterproof felt tunnel structure, characterized in that, It comprises the following steps: S1: first spray concrete on the tunnel wall, and form an initial support sprayed concrete layer after the concrete solidifies; S2: use steel nails to nail the geotextile on the sprayed concrete to form a first geotextile layer; S3: use a row of steel nails to fix the top of the self-adhesive aerogel thermal insulation waterproof felt on the initial support sprayed concrete layer and the first geotextile layer, and the self-adhesive aerogel thermal insulation waterproof felt naturally hangs down, and then gradually bonds the self-adhesive aerogel thermal insulation waterproof felt with the first geotextile layer from top to bottom to form a self-adhesive aerogel felt layer; S4: perform lining concrete pouring on the self-adhesive aerogel felt layer formed in step S3, and complete the construction after the concrete solidifies; The self-adhesive aerogel thermal insulation waterproof felt comprises, from inside to outside, a self-adhesive tape (4-1), a high-temperature waterproof breathable film (4-2), a silica aerogel layer (4-3), a second geotextile layer (4-4), and a self-adhesive waterproof board (4-5), wherein the self-adhesive tape (4-1), the high-temperature waterproof breathable film (4-2), the silica aerogel layer (4-3), and the second geotextile layer (4-4) are fixed by plastic threads (4-6), and the self-adhesive waterproof board (4-5) is bonded and fixed with the second geotextile layer (4-4); The thickness of the silica aerogel layer is 8 mm, the thermal conductivity is lower than 0.02 W / (m·k), the porosity is 80%-99.8%, and the specific surface area is 200-1000 m 2 / g.

2. The construction method of a high-geothermal-tunnel aerogel heat insulation waterproof felt tunnel structure according to claim 1, characterized in that, The self-adhesive aerogel thermal insulation waterproof felt is prepared by the following method: first, place two pieces of geotextile with a width of 2 m side by side to form a second geotextile layer (4-4); place four pieces of silica aerogel with a width of 1.0 m side by side on the inside of the second geotextile layer to form a silica aerogel layer (4-3); place a piece of TPU high-temperature waterproof breathable film with a width of 4 m on the inside of the silica aerogel layer; place 12 pieces of general self-adhesive tape with a width of 80 mm, with every three pieces forming a group, and the center distance of the general self-adhesive tape in each group being 50 cm, and each piece of silica aerogel corresponding to a group, and the center of the self-adhesive tape in the middle corresponding to the center of the silica aerogel; the layers are fixed by plastic threads; and place a piece of self-adhesive waterproof board (4-5) with a width of 4 m on the outermost layer and bond and fix it with the second geotextile layer (4-4).

3. The construction method of a high-geothermal-tunnel aerogel heat insulation waterproof felt tunnel structure according to claim 2, characterized in that, The plastic thread has a transverse stitching span of 60 mm, and the threading position is 10 mm away from the edge of the self-adhesive tape; and every 1 meter of length needs to be cut and reconnected for threading.

4. The construction method of a high-geothermal-tunnel aerogel heat insulation waterproof felt tunnel structure according to claim 1 or 2, characterized in that, The thickness of the self-adhesive waterproof board is 1.0-1.5 mm, and the VA content is 5.0%-5.5%.

5. The construction method of a high-geothermal-tunnel aerogel heat insulation waterproof felt tunnel structure according to any one of claims 1-3, characterized in that, The self-adhesive tape has a thickness of 0.1 mm; the high-temperature waterproof breathable film is made of thermoplastic polyurethane material; and the plastic thread is made of polytetrafluoroethylene and has a diameter of 2.3 mm.

6. The construction method of a high-geothermal-tunnel aerogel heat-insulation waterproof felt tunnel structure according to claim 1, characterized in that, The up-down and left-right spacing of the steel nails in step S2 is 50 cm, and the spacing of the steel nails in step S3 is 50 cm.

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