A shield tunnel with a tough grouting layer and a construction method

Abstract

The present invention belongs to the field of tunnel construction, and specifically discloses a shield tunnel with a tough grouting layer and a construction method, including a rubber base layer, in which fibers, a protective steel sheet, and an easily hydrolyzed gelatin film are all embedded; the protective steel sheet is obliquely embedded in the base layer to prevent the shield tail brush from damaging the fibers during shield tunneling, and the easily hydrolyzed gelatin film connects the protective steel sheet and the base layer, thereby forming a closed space with the protective steel sheet, and the fibers are placed in the closed space to avoid leakage of the fibers during construction. Since the steel sheet is obliquely embedded in the base layer, the steel sheet rebounds back to the inclined position after the shield tail brush passes. During synchronous grouting, the slurry flow direction is opposite to the inclined direction of the protective steel sheet. Under the impact of the slurry, the steel sheet tilts in the slurry flow direction, the gelatin leaks out and decomposes under the action of the slurry, and the fibers pop out and contact the grouting layer to form a fiber grouting layer. The fiber grouting layer improves the toughness and durability of the grouting layer, and avoids long-term degradation of the cement or cement water glass grouting layer.

Description

Technical Field

[0001] The invention relates to the field of tunnel construction, and in particular to a shield tunnel with a tough grouting layer and a construction method. Background Art

[0002] The grouting layer of the shield tunnel is the filling layer and connecting layer between the pipe segment and the surrounding rock. During the operation of the tunnel, the surrounding rock-grouting layer-pipe segment forms a stable force system. For hard rock shield tunnels, the strength of the grouting layer is much smaller than that of the pipe segment and the surrounding rock. The grouting layer is prone to deterioration under the action of train excitation and groundwater, which leads to voiding. The constraint effect on the pipe segment is reduced or even lost, which leads to stress concentration in the pipe segment, resulting in disasters such as misalignment, opening, leakage, and damage. In this regard, it is crucial to improve the toughness and durability of the grouting layer. Applying fibers to the grouting layer can effectively improve its toughness and durability, but applying fibers to the slurry during synchronous grouting of the shield can easily lead to clogging of the grouting pipe and reduced slurry diffusion, and the construction efficiency and grouting quality cannot be guaranteed. The external fiber layer can avoid the above problems, but the external fiber layer will entangle and scratch with the shield tail brush, resulting in fiber damage. Summary of the invention

[0003] In response to the above-mentioned deficiencies in the prior art, the present application provides a shield tunnel with a tough grouting layer and a construction method, aiming to improve the strength reduction problem caused by the poor toughness of the tunnel grouting layer, and solves the problem of synchronous grouting fiber pipe clogging through external patch-type fiber installation. In order to prevent the shield tail brush of the shield machine from cutting the fibers during the grouting process, a fish-scale full-enclosed fiber protection device is adopted.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In the first aspect, the present invention provides a shield tunnel with a tough grouting layer, which includes a tough grouting layer, wherein the tough grouting layer is arranged between the pipe segment and the tunnel, the tough grouting layer includes a rubber base layer, a slurry layer is arranged between the rubber base layer and the inner wall of the tunnel, and a plurality of obliquely arranged protective steel sheets and fibers are embedded on the rubber base layer, the protective steel sheets and the fibers are solidified together with the slurry, and before grouting, an easily hydrolyzable gelatin film connects the protective steel sheets and the rubber base layer to form a closed space, and the fibers are enclosed in the closed space, and after grouting, the easily hydrolyzable gelatin film is hydrolyzed.

[0006] As a further technical solution, the rubber base layer is polyethylene.

[0007] As a further technical solution, the inclination direction of the protective steel sheet is opposite to the flow direction of the slurry.

[0008] As a further technical solution, the fiber is polypropylene engineering fiber.

[0009] As a further technical solution, the fibers are embedded in the rubber base layer to a set depth.

[0010] As a further technical solution, the protective steel sheet is a fish-scale-shaped flexible steel sheet.

[0011] As a further technical solution, the shape of the rubber base layer is the same as that of the tunnel segment.

[0012] As a further technical solution, the rubber base layer is adhered to the outer surface of the pipe segment.

[0013] In the second aspect, the present invention further proposes a construction method based on the above-mentioned shield tunnel with a tough grouting layer, as follows:

[0014] Step 1: fix the rubber base layer on the outer surface of the tube segment; embed a plurality of obliquely arranged protective steel sheets and fibers on the rubber base layer, and connect the protective steel sheets and the rubber base layer with an easily hydrolyzed gelatin film to form a closed space, and enclose the fibers in the closed space;

[0015] Step 2: The shield machine excavates, and the shield tail brush squeezes the protective steel sheet to protect the fiber.

[0016] Afterwards, the steel sheet rebounds back to the inclined position;

[0017] Step 3: grouting is performed through a grouting pipe by jetting. The easily hydrolyzed gelatin film dissolves and is broken by the impact of the grouting liquid. The protective steel sheet rebounds. The fibers extend out and are supported by the protective steel sheet. The fibers are contacted and mixed with the slurry. The fiber concrete layer solidifies and a high-toughness fiber grouting layer is formed.

[0018] As a further technical solution, a rubber base layer is adhered to the outer surface of the segment; before grouting, the inclination direction of the protective steel sheet is the same as the inclination direction of the shield tail brush.

[0019] Compared with the prior art, the composite pile structure for reducing the negative frictional resistance in the present application has the following advantages:

[0020] (1) The shield tunnel proposed in the present invention has fibers and protective steel sheets arranged in the grouting layer. The concrete provided with the fibers and the protective steel sheets is used as the grouting layer of the shield tunnel, thereby improving the toughness and strength of the grouting layer, solving the problem that the strength and toughness of the grouting layer are much lower than those of the rock layer and the pipe segment, and avoiding the risk of grouting layer deterioration caused by vehicle vibration.

[0021] (2) The present invention adopts an externally attached rubber base layer, on which fibers are embedded. Compared with the fiber implantation process during the segment casting process, the present invention avoids the problems of fiber lodging and fiber clogging the casting pipe during the casting process. The entire grouting layer adopts a patch method, which is more convenient for transportation and installation, and can reduce the risk of fiber damage during transportation.

[0022] (3) The present invention takes into account the risk of damage to the fiber by the tail brush of the shield machine during its movement. The fixed layer material is made of high molecular weight polyethylene rubber and an embedded scaly steel sheet protection device is provided to avoid direct damage to the fiber by the tail brush of the shield.

[0023] (4) The present invention uses easily hydrolyzed gelatin as a fixation for the scaly steel sheet protection device. During the grouting process of the shield machine, the moisture and impact force of the slurry are used to restore the protective steel sheet to its original position, provide support for the fiber after it is stretched, and prevent the fiber from falling over. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 It is a schematic diagram of a shield tunnel with a tough grouting layer proposed by the present invention;

[0026] Figure 2 is a schematic diagram of the protective steel sheet proposed by the present invention;

[0027] Figure 3 It is a schematic diagram of the grouting process of a shield tunnel with a tough grouting layer proposed by the present invention;

[0028] Figure 4 It is a schematic diagram of the protective steel sheet, polypropylene fiber and easily hydrolyzed gelatin film provided by the present invention being arranged on a rubber base layer;

[0029] In the figure: the distances or sizes between parts are exaggerated to show the positions of various parts, and the schematic diagram is for illustration only.

[0030] 1. Fiber grouting layer; 2. Surrounding rock; 3. Pipe segment; 4. Protective steel sheet; 5. Fiber; 6. Hydrolyzable gelatin film; 7. Rubber base layer. DETAILED DESCRIPTION

[0031] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0032] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless otherwise explicitly stated in the present invention, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "include" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof;

[0033] As introduced in the background technology, the shortcomings of the prior art exist. In order to solve the above technical problems, the present invention proposes a shield tunnel with a tough grouting layer and a construction method. The invention adopts a fiber layer attached to the outer surface of the pipe segment whose fibers are not damaged, which is of great significance to improving the toughness and durability of the grouting layer.

[0034] In a typical embodiment of the present invention, Figure 1 , Figure 2 As shown, this embodiment discloses a shield tunnel with a tough grouting layer, including a fiber grouting layer 1, a surrounding rock 2 and a pipe segment 3. The fiber grouting layer 1 is a tough grouting layer, which is arranged between the pipe segment 3 and the surrounding rock 2. The tough grouting layer includes a rubber base layer 7, a slurry layer is arranged between the rubber base layer 7 and the inner wall of the surrounding rock 2, and a plurality of inclined protective steel sheets 4 and fibers 5 are embedded on the rubber base layer 7. The protective steel sheets 4, the fibers 5 and the slurry are solidified together, and before grouting, an easily hydrolyzed gelatin film 6 is connected to the protective steel sheets 4 and the rubber. The adhesive base layer 7 forms a closed space, and the fiber 5 is enclosed in the closed space. The easily hydrolyzed gelatin film 6 is hydrolyzed after grouting, that is, the protective steel sheet 4 and the fiber 5 and the dissolved gelatin film are arranged in the fiber grouting layer 1; the fiber 5 and the protective steel sheet 4 are arranged in the grouting layer, and the concrete provided with the fiber 5 and the protective steel sheet 4 is used as the grouting layer of the shield tunnel, which improves the toughness and strength of the grouting layer, solves the problem that the strength and toughness of the grouting layer are much lower than those of the rock layer and the pipe segment, and avoids the risk of deterioration of the grouting layer caused by vehicle vibration.

[0035] Furthermore, the rubber base layer 7 can be made of a 5mm high molecular weight polyethylene rubber base layer 7, and the protective steel sheet 4 is obliquely embedded in the rubber base layer 7 to prevent the shield tail brush from damaging the fiber 5 during shield tunneling. The easily hydrolyzed gelatin film 6 connects the protective steel sheet 4 and the rubber base layer 7, thereby forming a closed space with the protective steel sheet 4. The fiber 5 is placed in the closed space to avoid leakage of the fiber 5 during construction. Figure 3 , Figure 4As shown; specifically, during the tunneling process of the shield machine, the shield tail brush and the steel sheet are tilted in the same direction, and the steel sheet is closed to the base layer to protect the fiber 5. Since the steel sheet is tilted and embedded in the base layer, the steel sheet rebounds back to the tilted position after the shield tail brush passes. During synchronous grouting, the slurry flow direction is opposite to the tilt direction of the protective steel sheet 4. Under the impact of the slurry, the steel sheet tilts in the slurry flow direction, the gelatin leaks out and decomposes under the action of the slurry, and the fiber 5 pops out and contacts the grouting layer to form a fiber grouting layer 1. The fiber grouting layer 1 will significantly improve the toughness and durability of the grouting layer and avoid long-term degradation of the cement or cement water glass grouting layer.

[0036] The above-mentioned rubber base layer 7 is prefabricated in advance. The external rubber base layer 7 with fibers 5 can avoid the problem of clogging the grouting pipe caused by pre-embedded fibers 5 in the pipe segment 3. The rubber base layer 7 is installed on the surface of the pipe segment 3 on site, and the side in contact with the pipe segment 3 is glued and filled with high-strength and high-sealing potting glue.

[0037] Furthermore, the above-mentioned fiber 5 can be made of polypropylene engineering fiber 5, which is embedded 5 cm inside the high molecular polyethylene rubber base layer 7 to ensure that the polypropylene engineering fiber 5 is not washed off during the grouting process of the grouting layer, and can provide sufficient toughness improvement after the grouting layer is formed to prevent the soft rubber base layer 7 from being scratched and damaged by the shield tail brush. The protective device of the fiber 5 is a fish scale-shaped anti-scratch flexible protective steel sheet 4, which is also embedded 5 cm inside the rubber base layer 7. During prefabrication, the protective steel sheet 4 is pressed and bent in the same direction, and the polypropylene engineering fiber 5 is bent and pressed under the protective steel sheet 4. The lodging height of the protective steel sheet 4 is controlled to be consistent, and the gap between the edge of the protective steel sheet 4 and the high molecular polyethylene rubber base layer 7 is covered with an easily hydrolyzed gelatin film 6 to prevent the protective steel sheet 4 from rebounding prematurely.

[0038] During the tunneling process of the shield machine, the shield tail brush moves along the direction of the fiber 5 protecting the steel sheet 4. The fiber 5 is not damaged on the line of action of the protective steel sheet 4. After the shield tail brush passes, the synchronous grouting slurry is opposite to the pouring direction of the protective steel sheet 4. Under the impact of the slurry, the water-soluble gelatin material is hydrolyzed. The protective steel sheet 4 stands up, and the fiber 5 pops out to form a fiber grouting layer 1 with the slurry.

[0039] During the grouting layer construction process, the shield tail brush will squeeze the protective steel sheet 4 of the fiber 5 into a fallen state during its movement. The fiber 5 is located in the protective space formed under the protective steel sheet 4 to prevent the fiber 5 from being damaged during the extrusion process. The shield tail brush only scratches the protective steel sheet 4, thereby realizing the protection of the fiber 5 during the construction of the shield machine fiber concrete grouting layer. When the grouting pipe starts to grout the protective steel sheet 4, the easily hydrolyzed gelatin film 6 will dissolve when it receives the concrete with a high water content sprayed by the grouting pipe, and the easily hydrolyzed gelatin will be broken under the impact of the grouting pipe. The protective steel sheet 4 will rebound under the action of elastic force and concrete. At this time, the fiber 5 will unfold under the scouring of the slurry, and the fiber 5 and the protective steel sheet 4 will be inclined in the grouting direction. The protective steel sheet 4 has a certain rigidity to support the fiber 5, thereby preventing the fiber 5 from falling over under the scouring of the slurry, so that the fiber 5 can be better combined with the cement slurry, thereby improving the toughness of the formed fiber 5 concrete grouting layer.

[0040] This embodiment also provides a tunnel having a separated patch type fiber concrete grouting layer structure with a fiber protection device, and the corresponding specific construction method is as follows:

[0041] Step 1: The high molecular weight polyethylene rubber base layer 7 for fixing the fiber 5 is installed on the surface of the pipe segment 3 on site using a high-strength and high-tightness potting glue; a plurality of inclined protective steel sheets 4 and fibers 5 are embedded on the rubber base layer 7, and an easily hydrolyzed gelatin film 6 connects the protective steel sheets 4 and the rubber base layer 7 to form a closed space, and the fiber 5 is enclosed in the closed space;

[0042] Step 2: The shield machine's traveling shield tail brush squeezes and collapses the protective steel sheet 4 of the traveling fiber 5 protection device to protect the polypropylene engineering fiber 5;

[0043] Step 3: After the shield tail is brushed, the grouting pipe is used for spraying grouting. The easily hydrolyzed gelatin film 6 is dissolved and broken by the impact of the grouting pipe. The protective steel sheet 4 rebounds, and the fiber 5 stretches and is supported by the protective steel sheet 4 to reach the ideal stress position.

[0044] Step 4: The fiber 5 concrete layer solidifies, and a high-toughness fiber grouting layer 1 is formed.

[0045] The shield tunnel obtained by the above construction method improves the toughness and strength of the grouting layer, solves the problem that the strength and toughness of the grouting layer are much lower than the rock layer and the pipe segment 3, and avoids the risk of grouting layer deterioration caused by vehicle vibration. Compared with the form of implanting fibers 5 during the casting process of the pipe segment 3, the problem of fiber 5 falling over and fiber 5 blocking the casting pipeline during the casting process is avoided, and the entire grouting layer adopts a patch method, which is more convenient for transportation and installation, and can reduce the risk of damage to fiber 5 during transportation. Easily hydrolyzable gelatin is used as a fixation for the scaly steel sheet protection device. During the grouting process of the shield machine, the moisture and impact of the slurry are used to restore the protective steel sheet 4 to its original position, and provide support for the fiber 5 after it is stretched to prevent the fiber 5 from falling over.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A shield tunnel with a tough grouting layer, characterized in that: The invention comprises a tough grouting layer, wherein the tough grouting layer is arranged between the pipe segment and the tunnel, the tough grouting layer comprises a rubber base layer, a slurry layer is arranged between the rubber base layer and the inner wall of the tunnel, and a plurality of obliquely arranged protective steel sheets and fibers are embedded on the rubber base layer, the protective steel sheets and the fibers are solidified with the slurry, and before grouting, an easily hydrolyzable gelatin film connects the protective steel sheets and the rubber base layer to form a closed space, and the fibers are enclosed in the closed space, and after grouting, the easily hydrolyzable gelatin film is hydrolyzed; The inclination direction of the protective steel sheet is opposite to the slurry flow direction; The protective steel sheet is a flexible steel sheet in the shape of fish scales; The rubber base layer is glued to the outer surface of the segment.

2. The shield tunnel with a tough grouting layer according to claim 1, characterized in that: The rubber base layer is polyethylene.

3. The shield tunnel with a tough grouting layer as claimed in claim 1, characterized in that: The fiber is polypropylene engineering fiber.

4. The shield tunnel with a tough grouting layer as claimed in claim 1, characterized in that: The fibers are embedded in the rubber base layer to a set depth.

5. The shield tunnel with a tough grouting layer as claimed in claim 1, characterized in that: The shape of the rubber base layer is the same as that of the tunnel segment.

6. The construction method of a shield tunnel with a tough grouting layer according to any one of claims 1 to 5, characterized in that: as follows: Step 1: fix the rubber base layer on the outer surface of the tube segment; embed a plurality of obliquely arranged protective steel sheets and fibers on the rubber base layer, and connect the protective steel sheets and the rubber base layer with an easily hydrolyzed gelatin film to form a closed space, and enclose the fibers in the closed space; Step 2: The shield machine excavates, and the shield tail brush squeezes the protective steel sheet to protect the fiber. Afterwards, the protective steel sheet rebounds back to the inclined position; Step 3: grouting is performed through a grouting pipe by jetting. The easily hydrolyzed gelatin film dissolves and is broken by the impact of the grouting liquid. The protective steel sheet rebounds. The fibers extend out and are supported by the protective steel sheet. The fibers are contacted and mixed with the slurry. The fiber concrete layer solidifies and a high-toughness fiber grouting layer is formed.

7. The construction method of a shield tunnel with a tough grouting layer according to claim 6, characterized in that: The rubber base layer is adhered to the outer surface of the segment; before grouting, the inclination direction of the protective steel sheet is the same as that of the shield tail brush.

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