Steel corrugated plate-geopolymer composite lining structure with shear connectors

Abstract

The invention provides a steel corrugated plate-geopolymer composite lining structure with shear connectors, and relates to the technical field of tunnel and underground engineering lining structures. According to the shearing force connecting piece, the geopolymer filling layer and the steel corrugated plate are effectively connected into a whole, shearing slippage of an interface is avoided, and the geopolymer filling layer and the steel corrugated plate can completely cooperatively work and jointly bear surrounding rock pressure; due to the full play of the composite effect, the bearing capacity of the composite lining is far higher than that of simply adding the strength of the composite lining and the composite lining, and particularly, the bending resistance and the shearing resistance are greatly improved; the tight combination prevents the accumulation of interface water and the corrosion of steel, and prolongs the service life of the structure.

Description

Technical Field

[0001] This invention relates to the field of tunnel and underground engineering lining structure technology, and more specifically, to a steel corrugated plate-polymer composite lining structure with shear connectors. Background Technology

[0002] When using corrugated steel sheets for tunnel reinforcement, the bonding and coordinated stress distribution between the sheets and the internal concrete or mortar filling are crucial. Poor force transmission at the interface can easily lead to separation between the corrugated steel sheet and the filling layer, creating a "two-layer" phenomenon that prevents the formation of a composite whole and significantly weakens the reinforcement effect. Traditional smooth corrugated sheets are prone to this problem. Therefore, we propose an improvement: a corrugated steel sheet-polymer composite lining structure with shear connectors. Summary of the Invention

[0003] This invention provides a corrugated steel plate-polymer composite lining structure with shear connectors, comprising: Corrugated steel sheet, used as an inner bearing and restraint component; A geopolymer filling layer is filled between the corrugated steel plate and the original tunnel lining, serving as a force transmission layer and a pressure-bearing body. Shear connectors are provided on the outer surface of the corrugated steel plate; The corrugated steel plate is connected to the original tunnel lining by anchor bolts. The geopolymer filling layer wraps around the shear connector and penetrates into its holes or uneven areas, forming a mechanical interlock after solidification.

[0004] As a preferred technical solution of this application, the shear connector includes welded studs: several cylindrical head studs are welded perpendicularly to the surface of the corrugated steel plate at the troughs or crests of the plate.

[0005] As a preferred technical solution of this application, the shear connector includes perforated stiffening ribs: vertical or circumferential stiffening steel strips with holes are welded to the outer surface of the corrugated steel plate.

[0006] As a preferred technical solution of this application, the shear connector includes a specially designed waveform: the waveform of the corrugated steel plate is designed as a non-smooth trapezoidal wave, a waveform with reverse bending, or protrusions or pits are pressed on the wave surface.

[0007] As a preferred technical solution of this application, the anchor is a chemical anchor or expansion bolt, arranged in a quincunx or rectangular array along the circumferential and longitudinal directions of the corrugated steel plate, and the anchoring depth extends into the original tunnel lining by no less than 10 times the diameter of the anchor.

[0008] As a preferred technical solution of this application, the joint between adjacent corrugated steel plates is also filled with sealant, and the sealant is polyurethane sealant.

[0009] As a preferred technical solution of this application, the geopolymer filling layer adopts an inorganic polymer material; the composition and weight parts of the inorganic polymer material include: Fly ash: accounting for 40%-60%; Granulated blast furnace slag powder: accounting for 20%-40%; Metakaolin: 0%-15%; Alkali activator, including a composite alkali activator solution prepared from water glass and sodium hydroxide, is used in a liquid-solid ratio (to the mass of the cementitious material) of 0.35-0.50. Fine aggregates are made of natural river sand or manufactured sand, with a fineness modulus controlled between 2.3 and 2.6, a maximum particle size of no more than 4.75 mm, and their volume accounts for 30%-45% of the total volume.

[0010] As a preferred technical solution of this application, it also includes: The admixture accounts for 0.5-1.2%, and the admixture is a polycarboxylate superplasticizer.

[0011] As a preferred technical solution of this application, the method for preparing inorganic polymer materials includes: Dry mixing: Premixing dry materials such as fly ash, slag, and fine aggregates evenly in a mixer; Activator preparation: Dissolve solid sodium hydroxide in water glass, let stand and cool to room temperature to form a composite alkali activator; Wet mixing: Add the aqueous solution of compound alkali activator and additives to the dry material and stir for 3-5 minutes until a uniform slurry with suitable fluidity is formed.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: In the scheme of this application: 1. Improved structural integrity: The shear connector effectively connects the geopolymer filling layer and the corrugated steel plate into a whole, avoiding shear slip at the interface, enabling the two to work together and jointly bear the pressure of the surrounding rock.

[0013] 2. Enhanced load-bearing capacity: Due to the full utilization of the composite effect, the load-bearing capacity of this composite lining is much higher than that of simply adding the strengths of the two, especially the bending and shear load-bearing capacity is greatly improved.

[0014] 3. Good durability: The tight bond prevents the accumulation of interface water and corrosion of steel, thus extending the structural life.

[0015] 4. Full utilization of material properties: This allows both high tensile strength steel and high compressive strength geopolymer to be used to their fullest potential in the composite structure, making the best use of resources and achieving economic efficiency. Attached Figure Description

[0016] Figure 1 A structural schematic diagram of the steel corrugated plate-polymer composite lining structure with shear connectors provided in this application; Figure 2 A typical mass ratio range diagram of the inorganic polymer materials provided in this application; Figure 3 A schematic diagram of the welded stud type provided in this application; Figure 4 This is a schematic diagram of the perforated stiffening rib type provided in this application; Figure 5 A schematic diagram showing the use of custom waveforms and raised waveforms in the corrugated steel sheet provided in this application; Figure 6 This is a schematic diagram of the stress mechanism of the composite lining provided in this application. Detailed Implementation

[0017] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0018] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the embodiments of the present invention can be combined with each other.

[0019] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0020] For an example, please refer to... Figure 1 A corrugated steel plate-polymer composite lining structure with shear connectors, comprising: Corrugated steel sheet, used as an inner bearing and restraint component; A geopolymer filling layer is filled between the corrugated steel plate and the original tunnel lining, serving as a force transmission layer and a pressure-bearing body. A shear connector is provided on the outer surface of the corrugated steel plate to enhance the mechanical interlocking force and shear resistance between it and the geopolymer filler layer; The corrugated steel plate is connected to the original tunnel lining by anchor bolts. The geopolymer filling layer wraps around the shear connector and penetrates its holes or uneven areas, forming a mechanical interlock after solidification.

[0021] Furthermore, such as Figure 3As shown, the shear connector includes welded studs: several cylindrical head studs are welded perpendicularly to the surface of the corrugated steel plate at the troughs or crests of the plate.

[0022] Furthermore, such as Figure 4 As shown, the shear connector includes perforated stiffening ribs: vertical or circumferential stiffening steel strips with holes are welded to the outer surface of the corrugated steel plate; the perforated steel strips are continuously welded, and the geopolymer penetrates into the holes to form locking keys.

[0023] Furthermore, such as Figure 5 As shown, the shear connector includes a special waveform: the waveform of the corrugated steel plate is designed as a non-smooth trapezoidal wave, a wave with reverse bending, or protrusions or pits are pressed on the wave surface to increase the mechanical interlocking effect.

[0024] That is, the shear connectors adopt one or more of the following types: welded studs, perforated stiffening ribs, and specially designed waveforms.

[0025] Furthermore, the anchor bolts are chemical anchors or expansion bolts, arranged in a staggered or rectangular array along the circumferential and longitudinal directions of the corrugated steel plate, with an anchoring depth extending into the original tunnel lining by no less than 10 times the diameter of the anchor bolt.

[0026] Furthermore, the joints between adjacent corrugated steel plates are filled with sealant, which is polyurethane sealant, with a filling width of not less than 50mm and a thickness of not less than 10mm.

[0027] Reference Figure 6 Schematic diagram of the stress mechanism of composite lining, key stress mechanisms: Geopolymers expand laterally under pressure. Shear connectors resist relative slippage; Corrugated steel plates provide circumferential constraint, thus restraining polymer expansion. This forms a three-dimensional force system of "constraint-filling-anchoring"; In the diagram, ↗↖ indicates the direction of shear force transmission at the interface.

[0028] In summary, the technical advantages of this composite lining structure are achieved through shear connectors: Mechanical interlocking effect: The geopolymer penetrates into the gaps of the connectors and forms a strong interlock after solidification; Effective stress transfer: Shear connectors transform interfacial shear forces into triaxial constraints on the geopolymer; Maximizing material properties: The tensile strength of steel and the compressive strength of geopolymers work synergistically; Enhanced durability: Tight bonding prevents interface peeling and intrusion of corrosive media; This design solves the technical problem of "two separate layers" in traditional reinforcement, providing an innovative solution for the green reinforcement of old tunnels.

[0029] Furthermore, the geopolymer filling layer is made of an inorganic polymer material; the composition and weight parts of the inorganic polymer material include: Fly ash: accounting for 40%-60%, must meet the Class F Grade I or II standard in "Fly Ash for Cement and Concrete" (GB / T1596); Granulated blast furnace slag powder: accounting for 20%-40%, must meet the S95 grade or above standard in "Granulated blast furnace slag powder for cement, mortar and concrete" (GB / T18046). Slag can significantly improve the early strength and density of geopolymers. Metakaolin: accounting for 0%-15%, as a supplementary aluminum and silicon source, can optimize the reaction process and product stability; Alkali activator, including a composite alkali activator solution prepared from water glass and sodium hydroxide, is used in a liquid-to-solid ratio (mass ratio) of 0.35-0.50 to the cementitious material; the water glass modulus (SiO2 / Na2O molar ratio) is between 1.2-2.2; sodium hydroxide is used to adjust the modulus of the water glass and provide a strongly alkaline environment; the amount of sodium hydroxide is 8%-15% of the mass of the water glass. Fine aggregate (filler and toughening) is made of natural river sand or manufactured sand, with a fineness modulus controlled between 2.3 and 2.6, a maximum particle size of no more than 4.75 mm, and its volume accounts for 30%-45% of the total volume.

[0030] It also includes: admixtures, accounting for 0.5-1.2%, of which polycarboxylate superplasticizers are used.

[0031] Reference Figure 2 , Figure 2 The invention provides a typical mass ratio range for inorganic polymer materials; the core cementitious materials (fly ash and slag) are all industrial solid wastes, realizing "turning waste into treasure" and conforming to the core concept of green and low-carbon development; the carbon emissions from geopolymer production are far lower than those of ordinary silicate cement. According to life cycle assessment (LCA), its carbon emission factor can be as low as 0.2-0.4 tCO2e / t, while that of ordinary cement is about 0.82 tCO2e / t; its 3-day strength can reach more than 70% of its 28-day strength, which is conducive to accelerating the construction progress; good volume stability helps to reduce shrinkage stress at the interface with the corrugated steel plate; the geopolymer system is highly alkaline and its hydration products are stable, which can effectively protect the internal steel bars and corrugated steel plates, while also having strong resistance to corrosion by media such as sulfates; its slurry is fine and has high bonding strength with the interface of old concrete and steel surface. This specific composition provides a clear material science basis for the implementation of this invention and is the key to ensuring that the composite lining structure achieves the expected mechanical performance and environmental benefits.

[0032] Furthermore, methods for preparing inorganic polymer materials include: Dry mixing: Premixing dry materials such as fly ash, slag, and fine aggregates evenly in a mixer; Activator preparation: Dissolve solid sodium hydroxide in water glass, let stand and cool to room temperature to form a composite alkali activator; Wet mixing: Add the aqueous solution of compound alkali activator and additives to the dry material and stir for 3-5 minutes until a uniform slurry with suitable fluidity is formed.

[0033] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. A steel corrugated plate-polymer composite lining structure with shear connectors, characterized in that, include: Corrugated steel sheet, used as an inner bearing and restraint component; A geopolymer filling layer is filled between the corrugated steel plate and the original tunnel lining, serving as a force transmission layer and a pressure-bearing body. Shear connectors are provided on the outer surface of the corrugated steel plate; The corrugated steel plate is connected to the original tunnel lining by anchor bolts. The geopolymer filling layer wraps around the shear connector and penetrates into its holes or uneven areas, forming a mechanical interlock after solidification.

2. The steel corrugated plate-polymer composite lining structure with shear connectors according to claim 1, characterized in that, The shear connector includes welded studs: several cylindrical head studs are welded perpendicularly to the surface of the corrugated steel plate at the troughs or crests of the plate.

3. The steel corrugated plate-polymer composite lining structure with shear connectors according to claim 1 or 2, characterized in that, The shear connector includes perforated stiffening ribs: vertical or circumferential stiffening steel strips with holes are welded to the outer surface of the corrugated steel plate.

4. The steel corrugated plate-polymer composite lining structure with shear connectors according to any one of claims 1-3, characterized in that, The shear connector includes a specially designed waveform: the waveform of the corrugated steel plate is designed as a non-smooth trapezoidal wave, a wave with reverse bending, or a protrusion or pit is pressed into the wave surface.

5. The steel corrugated plate-polymer composite lining structure with shear connectors according to any one of claims 1, characterized in that, The anchors are chemical anchors or expansion bolts, arranged in a staggered or rectangular array along the circumferential and longitudinal directions of the corrugated steel plate, with an anchoring depth extending into the original tunnel lining by no less than 10 times the diameter of the anchor.

6. The corrugated steel plate-polymer composite lining structure with shear connectors according to any one of claims 1, characterized in that, The joints between adjacent corrugated steel plates are also filled with sealant, which is polyurethane sealant.

7. The steel corrugated plate-polymer composite lining structure with shear connectors according to claim 1, characterized in that, The geopolymer filling layer is made of inorganic polymer material.

8. The steel corrugated plate-polymer composite lining structure with shear connectors according to claim 7, characterized in that, The components and weight parts of the inorganic polymer material include: Fly ash: accounting for 40%-60%; Granulated blast furnace slag powder: accounting for 20%-40%; Metakaolin: 0%-15%; Alkali activator, including a composite alkali activator solution prepared from water glass and sodium hydroxide, is used in a liquid-solid ratio (to the mass of the cementitious material) of 0.35-0.

50. Fine aggregates are made of natural river sand or manufactured sand, with a fineness modulus controlled between 2.3 and 2.6, a maximum particle size of no more than 4.75 mm, and their volume accounts for 30%-45% of the total volume.

9. The steel corrugated plate-polymer composite lining structure with shear connectors according to claim 8, characterized in that, Also includes: The admixture accounts for 0.5-1.2%, and the admixture is a polycarboxylate superplasticizer.

10. The steel corrugated plate-polymer composite lining structure with shear connectors according to claim 9, characterized in that, Methods for preparing inorganic polymer materials include: Dry mixing: Premixing dry materials such as fly ash, slag, and fine aggregates evenly in a mixer; Activator preparation: Dissolve solid sodium hydroxide in water glass, let stand and cool to room temperature to form a composite alkali activator; Wet mixing: Add the aqueous solution of compound alkali activator and additives to the dry material and stir for 3-5 minutes until a uniform slurry with suitable fluidity is formed.

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