In-situ mixing and spraying construction method of ferri-aluminate cement concrete for high-speed railway tunnel

Abstract

This invention discloses an in-situ mixing and spraying method for high-speed railway tunnels using aluminoferrite cement concrete, comprising the following steps: S1: Equipment preparation, moving the mixer truck, the initial support wet spraying machine, and the batching truck loaded with materials to the tunnel face, while simultaneously leveling the ground to ensure the mixer truck and the initial support wet spraying machine are in a docking state, and then docking the batching truck with the mixer truck. Two batching trucks are also provided to ensure that there are batching trucks fully loaded with materials at the tunnel face; S2: Starting mixing, the batching truck discharges materials and simultaneously transports each material to the mixer truck in proportion for mixing. After the forced mixer in the mixer truck performs the first mixing, the mixture is conveyed to the discharge mixing tank. After the discharge mixing tank performs the second mixing, the mixture is conveyed to the initial support wet spraying machine for concrete spraying, thus achieving the initial support. Both the batching truck and the mixer truck can move synchronously with the tunnel construction, and the mixer truck achieves real-time mixing before conveying the mixture to the initial support wet spraying machine for initial support spraying, ensuring that the aluminoferrite cement concrete is sprayed to the corresponding position before curing.

Description

Technical Field

[0001] This invention belongs to the field of railway tunnel concrete mixing technology, specifically relating to an in-situ mixing and spraying method for high-speed railway tunnels using ferroaluminate cement concrete. Background Technology

[0002] During the construction of high-speed railway tunnels, various environmental conditions are encountered. In complex geological environments with ultra-high water pressure, ultra-high water inflow, and high sulfate erosion, sulfate erosion can easily lead to the deterioration of the tunnel concrete lining structure, a decrease in load-bearing capacity, and even failure, thus directly threatening the long-term operational safety and durability of the tunnel. Based on the non-corrosive properties of aluminoferrite cement in chemical environments, its use in high-speed railway tunnels is currently being promoted.

[0003] In practical use, concrete prepared with aluminoferrite cement has a fast curing time, making it impossible to mix it outside the tunnel and transport it inside for use. If the current integrated mixer truck is used, the hopper of the mixer truck is too small, requiring frequent replenishment, which seriously reduces construction efficiency. Summary of the Invention

[0004] This invention proposes an in-situ mixing and spraying method for high-speed railway tunnels using aluminate cement concrete. This method not only effectively ensures that the aluminate cement concrete is fully mixed, but also reduces the time wasted on material loading and unloading during the initial support spraying.

[0005] Therefore, the technical solution adopted in this invention is as follows: an in-situ mixing and spraying construction method for high-speed railway tunnels using aluminoferrite cement concrete, comprising the following steps:

[0006] S1: Equipment preparation: Move the mixer truck, the initial wet spraying machine, and the batching truck loaded with material to the working face. At the same time, repair the ground so that the mixer truck and the initial wet spraying machine are in a docking state. Then dock the batching truck with the mixer truck. There are two batching trucks to ensure that there are batching trucks loaded with material at the working face.

[0007] S2: Start mixing. The batching truck unloads materials and transports each material to the mixer truck in proportion for mixing. The forced mixer in the mixer truck performs the first mixing and then transports the mixture to the discharge mixing drum. After the discharge mixing drum performs the second mixing, it is transported to the initial support wet spraying machine for concrete spraying to achieve the initial support.

[0008] As a preferred embodiment of the above scheme, the batching vehicle includes a batching platform mounted on a batching chassis. Multiple hoppers are arranged sequentially from left to right on the batching platform, and each hopper is equipped with a metering system at its outlet for measuring the amount of material discharged. A batching conveyor belt is mounted on the batching platform below all the hoppers, so that when material is discharged from all the hoppers, it falls onto the batching conveyor belt.

[0009] More preferably, the mixer truck includes a mixing platform mounted on a mixing chassis, and both the forced mixing tank and the mixing platform are mounted on the mixing platform. The mixing platform is equipped with a feeding conveyor belt, which can transport ingredients of various weights to the feeding conveyor belt. The feeding conveyor belt is used to transport each ingredient into the forced mixing tank.

[0010] Further preferably, the mixing platform is equipped with an additive bin and a water scale, the batching vehicle is equipped with a water tank, and a connecting pipe is detachably provided between the water tank and the water scale, and the water scale is connected to the forced mixing tank through a pipe.

[0011] Further preferably, the feeding conveyor belt includes a fixed section and a folded section. One end of the fixed section is set on the mixing platform through a feeding bracket, and one end of the folded section is hinged to the fixed section. Both the folded section and the fixed section are provided with conveyor brackets for supporting the conveyor belt. All conveyor belt brackets use the same conveyor belt, and the conveyor belt is provided with patterns to prevent the ingredients from falling off.

[0012] Further preferably, the feeding conveyor belt includes a fixed section and a folded section. One end of the fixed section is set on the mixing platform through a feeding bracket, and one end of the folded section is hinged to the fixed section. Both the folded section and the fixed section are provided with conveyor brackets for supporting the conveyor belt. All conveyor belt brackets use the same conveyor belt, and the conveyor belt is provided with patterns to prevent the ingredients from falling off.

[0013] In a further preferred embodiment, the driving platform of the mixing chassis is located below the feeding conveyor belt, and the driving platform is provided with support columns for supporting the feeding conveyor belt.

[0014] In a further preferred embodiment, the feeding conveyor belt is provided with side baffles on both outer sides near one end of the batching conveyor belt to prevent batching from splashing, and the feeding conveyor belt is provided with a main baffle to prevent batching from falling downwards.

[0015] The beneficial effects of this invention are:

[0016] 1) Both the batching truck and the mixer truck can move synchronously with the tunnel construction. The mixer truck can mix the concrete in real time and then transport it to the initial support wet spraying machine to achieve initial support spraying, ensuring that the aluminate cement concrete is sprayed to the corresponding position before curing.

[0017] 2. The batching and mixing sections are separated, and multiple batching vehicles are provided. It is ensured that there is always a batching vehicle working at the working face, which can effectively reduce the time wasted in batching during the initial support stage, thereby ensuring construction efficiency.

[0018] 3) The mixer truck is equipped with a forced mixing drum and a discharge mixing drum, which can effectively ensure that the aluminate cement concrete is mixed evenly, thereby ensuring the quality of the concrete after mixing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the batching cart in this embodiment.

[0020] Figure 2 This is a schematic diagram of the mixer truck in this embodiment.

[0021] Attached reference numerals: 1. Batching chassis, 2. Batching platform, 3. Silo, 4. Metering system, 5. Batching conveyor belt, 6. Mixing chassis, 7. Mixing platform, 8. Forced mixing tank, 9. Feeding conveyor belt, 9a. Fixed section, 9b. Folding section, 10. Discharge mixing tank, 11. Additive silo, 12. Water scale, 13. Water tank, 14. Feeding bracket, 15. Conveying bracket, 16. Folding fixed bracket, 17. Electric hoist, 18. Folding lifting bracket, 19. Driving platform, 20. Support column, 21. Side baffle. Detailed Implementation

[0022] The present invention will be further described below with reference to the embodiments and accompanying drawings:

[0023] like Figure 1-2 As shown, an in-situ mixing and spraying method for high-speed railway tunnels using aluminoferrite cement concrete is described.

[0024] Step 1: Equipment preparation. Move the mixer truck, the initial wet spraying machine, and the batching truck loaded with material to the working face. At the same time, repair the ground to ensure that the mixer truck and the initial wet spraying machine are in a docking position. Then dock the batching truck with the mixer truck. Also, equip two batching trucks to ensure that there are batching trucks loaded with material at the working face.

[0025] Among them, such as Figure 1 As shown, the batching vehicle includes a batching platform 2 mounted on a batching chassis 1. Multiple hoppers 3 are arranged sequentially from left to right on the batching platform 2, and each hopper 3 has a metering system 4 at its outlet for measuring the discharge volume. A batching conveyor belt 5 is mounted on the batching platform 2 below all the hoppers 3, allowing all materials to fall onto the batching conveyor belt during discharge. The metering system and the batching conveyor belt also utilize existing technology. Preferably, the end of the batching conveyor belt facing the mixer truck is lower than the other end, causing the conveyor belt to tilt, facilitating the material falling onto the loading conveyor belt.

[0026] like Figure 2As shown, the mixer truck includes a mixing platform 7 mounted on a mixing chassis 6. A forced mixing drum 8 is mounted on the mixing platform 7, and a feeding conveyor belt 9 is also mounted on the mixing platform 7. A batching conveyor belt 5 transports ingredients of various weights onto the feeding conveyor belt 9, which then transports the ingredients into the forced mixing drum 8. To ensure sufficient concrete mixing time, a discharge mixing drum 10 is also mounted on the mixing platform 7, and the discharge port of the forced mixing drum 8 is connected to the inlet of the discharge mixing drum 10. The detailed structures of both the forced mixing drum and the discharge mixing drum utilize existing technology.

[0027] The material silos include sand silos, gravel silos, cement silos, and fly ash silos. To facilitate the addition of additives, an additive silo 11 and a water scale 12 are equipped on the mixing platform 7. A water tank 13 is installed inside the batching vehicle, and a detachable connecting pipe is installed between the water tank 13 and the water scale 12. The water scale 12 is connected to the forced mixing drum 8 via a pipe. The water scale is used to measure the amount of water added. The additive silo is quantitatively set according to the amount of additives to ensure the correct concrete mix proportion. The water scale is existing technology and will not be described in detail here.

[0028] Since the feeding conveyor belt is suspended, in order to ensure that the suspended end of the feeding conveyor belt does not affect the movement of the mixer truck when it moves, the feeding conveyor belt 9 includes a fixed section 9a and a folded section 9b. One end of the fixed section 9a is set on the mixing platform 7 through the feeding bracket 14, and one end of the folded section 9b is hinged to the fixed section 9a. Both the folded section 9b and the fixed section 9a are provided with conveyor brackets 15 for supporting the conveyor belt. All conveyor belt brackets 15 use the same conveyor belt, and the conveyor belt is provided with patterns to prevent the ingredients from falling off.

[0029] To achieve the folding of the folding section, the feeding conveyor belt 9 includes a fixed section 9a and a folding section 9b. One end of the fixed section 9a is mounted on the mixing platform 7 via a feeding bracket 14, and one end of the folding section 9b is hinged to the fixed section 9a. Both the folding section 9b and the fixed section 9a are equipped with conveyor brackets 15 for supporting the conveyor belt. All conveyor belt brackets 15 use the same conveyor belt, and the conveyor belt is patterned to prevent the ingredients from falling off. Meanwhile, an electric hoist 17 is mounted on the fixed section via a folding fixing bracket 16, and a folding lifting bracket 18 is mounted on the folding section. A cable connects the electric hoist 17 and the folding lifting bracket 18.

[0030] To facilitate operation on the mixing platform, operating platforms are provided on the left and right sides of the forced mixing tank 8 on the mixing platform 7. The driving platform 19 of the mixing chassis 6 is positioned below the feeding conveyor belt 9, and the driving platform 19 is equipped with support columns 20 for supporting the feeding conveyor belt 9. The support columns are located on a fixed section, and the discharge mixing tank is located below the forced mixing tank.

[0031] To ensure smooth movement of the mixer truck and batching truck, both the mixing chassis and the batching chassis are heavy-duty chassis. The initial support wet spraying machine is existing technology.

[0032] Step 2: Start mixing. While the batching truck is unloading materials, it transports each material to the mixer truck in proportion for mixing. After the forced mixer 8 in the mixer truck performs the first mixing, the mixture is conveyed to the discharge mixing drum 10. After the discharge mixing drum 10 performs the second mixing, the mixture is conveyed to the initial support wet spraying machine for concrete spraying, thus realizing the initial support spraying.

[0033] The weight ratio of each component is as follows: cement: fly ash: manufactured sand: coarse aggregate (5-10mm): water-reducing agent: air-entraining agent: water = 432: 48: 1186: 662: 9.60: 2.40: 111.

[0034] This construction method is applicable to the full-section tunnel method, the two-stage method, and the three-stage method. When using the in-situ mixing process in the three-stage method, the height and length of the steps need to be adjusted appropriately.

[0035] When the batching truck is unloading materials, it should first add powder materials and then add aggregates, that is, cement and fly ash first, followed by sand and coarse aggregates, to prevent the powder materials from sticking to the conveyor due to the moisture in the aggregates wetting the conveyor.

Claims

1. A method for in-situ mixing and spraying high-speed railway tunnels using aluminoferroaluminate cement concrete, characterized in that, Includes the following steps: S1: Equipment preparation: Move the mixer truck, the primary support wet spraying machine, and the batching truck loaded with material to the working face. At the same time, repair the ground so that the mixer truck and the primary support wet spraying machine are in a docking state. Then dock the batching truck with the mixer truck. Two batching trucks are also equipped to ensure that there are batching trucks loaded with material at the working face. S2: Start mixing. The batching truck unloads the materials and transports each material to the mixing truck in proportion for mixing. After the forced mixer (8) in the mixing truck performs the first mixing, it is transported to the discharge mixing drum (10). After the discharge mixing drum (10) performs the second mixing, it is transported to the initial support wet spraying machine for concrete spraying to achieve the initial support.

2. The in-situ mixing and spraying method for high-speed railway tunnels using aluminate cement concrete as described in claim 1, characterized in that: The batching vehicle includes a batching platform (2) set on a batching chassis (1). Multiple hoppers (3) are arranged sequentially from left to right on the batching platform (2), and a metering system (4) for measuring the amount of material discharged is set at the discharge port of each hopper (3). A batching conveyor belt (5) is set on the batching platform (2) located below all the hoppers (3). When all the hoppers discharge material, it can fall onto the batching conveyor belt.

3. The in-situ mixing and spraying method for high-speed railway tunnels using aluminate cement concrete as described in claim 2, characterized in that: The mixer truck includes a mixing platform (7) set on a mixing chassis (6). The forced mixing tank (8) and the mixing platform (7) are both set on the mixing platform (7). The mixing platform (7) is equipped with a feeding conveyor belt (9). The batching conveyor belt (5) can transport the batching materials of various weights to the feeding conveyor belt (9). The feeding conveyor belt (9) is used to transport the batching materials into the forced mixing tank (8).

4. The in-situ mixing and spraying method for high-speed railway tunnels using aluminoferroaluminate cement concrete as described in claim 3, characterized in that: The mixing platform (7) is equipped with an additive bin (11) and a water scale (12). The batching vehicle is equipped with a water tank (13), and a connecting pipe is detachably provided between the water tank (13) and the water scale (12). The water scale (12) is connected to the forced mixing tank (8) through a pipe.

5. The in-situ mixing and spraying method for high-speed railway tunnels using aluminoferroaluminate cement concrete as described in claim 3, characterized in that: The feeding conveyor belt (9) includes a fixed section (9a) and a folded section (9b). One end of the fixed section (9a) is set on the mixing platform (7) through a feeding bracket (14). One end of the folded section (9b) is hinged to the fixed section (9a). Both the folded section (9b) and the fixed section (9a) are provided with a conveyor bracket (15) for supporting the conveyor belt. All conveyor belt brackets (15) use the same conveyor belt, and the conveyor belt is provided with a pattern to prevent the ingredients from falling off.

6. The in-situ mixing and spraying method for high-speed railway tunnels using aluminoferroaluminate cement concrete as described in claim 5, characterized in that: The feeding conveyor belt (9) includes a fixed section (9a) and a folded section (9b). One end of the fixed section (9a) is set on the mixing platform (7) through a feeding bracket (14). One end of the folded section (9b) is hinged to the fixed section (9a). Both the folded section (9b) and the fixed section (9a) are provided with a conveyor bracket (15) for supporting the conveyor belt. All conveyor belt brackets (15) use the same conveyor belt, and the conveyor belt is provided with a pattern to prevent the ingredients from falling off.

7. The in-situ mixing and spraying method for high-speed railway tunnels using aluminate cement concrete as described in claim 3, characterized in that: An electric hoist is installed on the fixed section via a folding fixed bracket, and a folding lifting bracket is installed on the folding section, with a cable connecting the electric hoist and the folding lifting bracket.

8. The in-situ mixing and spraying method for high-speed railway tunnels using aluminoferroaluminate cement concrete as described in claim 3, characterized in that: The driving platform (19) of the mixing chassis (6) is located below the feeding conveyor belt (9), and the driving platform (19) is provided with a support column (20) for supporting the feeding conveyor belt (9).

9. The in-situ mixing and spraying method for high-speed railway tunnels using aluminoferrate cement concrete as described in claim 3, characterized in that: The feeding conveyor belt (9) has side baffles (21) on both outer sides near one end of the batching conveyor belt to prevent the batching material from splashing. The feeding conveyor belt (9) also has a main baffle to prevent the batching material from falling downwards.

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