Construction method of waterproof and anti-pollution shield tunnel underneath penetrating riverbed

Abstract

The invention discloses a construction method of a waterproof and anti-pollution shield tunnel underneath penetrating a riverbed, outer pipe pieces which are annularly distributed are laid in the shield tunnel, and the adjacent outer pipe pieces are connected through a concave-convex tenon structure and are fixedly assembled through fastening bolts. According to the waterproof and anti-pollution shield tunnel construction method, the secondary lining technology is combined through design, the waterproof mortar material is combined in an original shield tunnel, the waterproof and anti-pollution functions of the shield tunnel are improved, the waterproof and anti-pollution shield tunnel construction method underneath passing through the riverbed has the waterproof and anti-pollution advantages, pipe piece leakage can be avoided, the waterproof and anti-pollution functions of the shield tunnel are improved from the source, and the construction cost is reduced. And the multiple waterproof pads are adopted between the pipe pieces, the damping and waterproof functions can be effectively achieved, and the three grouting materials are utilized, so that the functions of structural strength enhancing, secondary waterproof and leakage point blocking are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnels, in particular to a waterproof and pollution-proof shield tunnel construction method that passes under a riverbed. Background Art

[0002] Water-rich and changeable strata can easily lead to various major engineering accidents such as mud burst, water gushing, landslides, surface settlement, segment cracks, and shield machine head fall during shield construction, which have a significant impact on the project progress, safety, quality, and cost. Therefore, an effective grouting shield tunnel construction method for water-rich and changeable strata is urgently needed. Summary of the invention

[0003] The purpose of the present invention is to solve the difficult problem of shield tunnel construction in water-rich and changeable strata. Grouting reinforcement of shield tunnels in water-rich and changeable strata is more difficult than grouting construction with sleeve valve pipes on the ground. It is necessary to overcome the problems caused by groundwater in the tunnel and solve the quality problems of the pipe segments generated during the grouting process. In addition, the traditional mortise and tenon are arranged continuously and have low assembly precision. When misalignment occurs, only the mortise and tenon in partial contact play a shearing role, which makes it difficult to cope with the complex stratum pressure and cause the pipe segments to be damaged due to excessive local shear force, which seriously affects the stability and safety of the tunnel shield construction. In order to solve the above problems, the present invention provides a waterproof and pollution-proof shield tunnel construction method that passes under a riverbed.

[0004] The technical solution adopted by the present invention is as follows:

[0005] Step 1: After the shield machine starts, the outer segments are laid in a circular distribution in the shield tunnel. The adjacent outer segments are connected by a concave-convex structure and fixed and assembled by tightening bolts;

[0006] Step 2: When laying the outer segments in a circular distribution, use the reserved grouting holes of the outer segments to complete the grouting of the shield tunnel by synchronous grouting. When the shield machine advances forward to form a gap at the shield tail, the double-pump four-pipeline grouting pipe at the shield tail is used synchronously to grout symmetrically, evenly and fully. The speed should match the excavation speed. The average grouting speed is determined by the amount of grouting completed in the shield within the time it takes to complete one ring of excavation. To ensure uniform grouting, factors such as deviation correction, slurry leakage and shrinkage of grouting materials during the advancement process are considered. The grouting amount is 1.5-2 times the theoretical volume of the shield tail control gap, that is, the grouting amount behind each ring wall is 5.5-6.5m 3 ;

[0007] Step 3: Add water-stop rings at every 5 rings of outer segments to block the groundwater behind, reduce the waterproof pressure of the shield tunnel, improve the water-stop effect, and stabilize the segments; on the other hand, prevent water from the rear from entering the shield tunnel during the downhill section;

[0008] Step 4: After the shield tunnel grouting solidifies, secondary lining is carried out, the original water stop ring is removed, and the main reinforcement bracket, secondary reinforcement bracket and waterproof pad are laid on the basis of the original outer segment. The main reinforcement bracket is set at the interface, and the secondary reinforcement bracket is set at other annular parts. The fixing part adopts a chimeric structure to complete the positioning, and the inner segment and the outer segment are fixed and assembled with bolts;

[0009] Step 5: After the assembly is completed, secondary grouting is carried out and water stop rings are added to the inner segments of each ring;

[0010] Step 6: Check the leakage point and inject grout three times.

[0011] Preferably, the outer tube segment is arranged in the inner cavity of the shield tunnel and is distributed in a ring shape, the inner tube segment is arranged on one side of the outer tube segment, and tenon structures and grooves for interlocking are respectively provided between adjacent outer tube segments and inner tube segments, and waterproof pads arranged in pairs are provided between the outer tube segment and the inner tube segment. An assembly groove for installing the waterproof pad is provided on the side of the outer tube segment opposite to the inner tube segment, the main reinforcement bracket is arranged at the joint between the outer tube segment and the inner tube segment, and the secondary reinforcement bracket is arranged between two adjacent waterproof pads.

[0012] Preferably, the main reinforcement bracket includes a main reinforcement structure body, side empty grooves are opened on both sides of the top of the main reinforcement structure body, a flow cavity is opened on the top of the main reinforcement structure body, the inner cavity of the flow cavity is fixedly connected to a supporting keel, a number of overflow holes distributed at equal intervals are opened on both sides of the inner cavity of the flow cavity, the overflow holes are connected with the side empty grooves, and positioning strips are arranged on both sides of the top of the main reinforcement structure body.

[0013] Preferably, the secondary reinforcement bracket includes a secondary reinforcement structure body, a slurry flow groove is opened on the top of the secondary reinforcement structure body, the inner cavity of the slurry flow groove is fixedly connected to a support frame, both sides of the top and bottom of the secondary reinforcement structure body are fixedly connected with assembly protrusions, side flow grooves are opened on both sides of the top of the secondary reinforcement structure body, and secondary connection holes and main connection holes connecting the slurry flow groove and the side flow groove are opened on both sides of the inner cavity of the slurry flow groove.

[0014] Preferably, reinforcing ribs are fixedly connected to the surface of the support frame.

[0015] Preferably, the grouting material in step 2 is cement mortar, and its specific formula ratio is: cement: fly ash: bentonite: sand: water = 4.1:10:3:3.2:8.5.

[0016] Preferably, the grouting material in step five is a crack-resistant, waterproof and anti-fouling mortar, and its specific formula ratio is: composite fly ash: slag powder: basalt fiber = 100:200:1.

[0017] Preferably, the three groutings in step six are divided into a grouting stage and a sealing stage. The grouting stage uses a single-liquid slurry, namely cement slurry, and the water-cement ratio is 1:1; the sealing stage uses a double-liquid slurry, and the weight ratio of water to water glass is 3:1; the weight ratio of cement slurry to water-cement ratio is 1:1, the volume ratio of cement slurry to water glass is 1:1, and the grouting pressure is 2.5 to 3.5 bar. The grouting pressure and grouting amount are controlled to prevent the pipe segments from being squeezed out of position.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. The present invention combines the secondary lining technology through design, combines the waterproof mortar material in the original shield tunnel, and improves the waterproof and anti-fouling function of the shield tunnel. The waterproof and anti-pollution shield tunnel construction method under the riverbed has the advantages of waterproof and anti-fouling, can avoid leakage of the pipe segments, and improve the waterproof and anti-fouling function of the shield tunnel from the source. In addition, multiple waterproof pads are used between the pipe segments, which can effectively play the role of shock absorption and waterproofing.

[0020] 2. The present invention utilizes three kinds of grouting materials to respectively enhance the structural strength, secondary waterproofing and plugging the leakage points. Through the combined material setting, the waterproof and anti-fouling ability of the shield tunnel can be greatly enhanced, and the structural strength of the shield tunnel can be greatly enhanced to avoid later damage.

[0021] 3. The present invention innovatively adopts reinforced main reinforcement brackets and secondary reinforcement brackets to adapt to the existing shield tunnel under the riverbed in the original secondary lining technology. The main reinforcement brackets and secondary reinforcement brackets can realize the function of support and reinforcement during the secondary grouting process, and can improve the structural strength of the waterproof mortar.

[0022] 4. The present invention designs a row of distributed mortise and tenon segment structures, which connects two adjacent mortise and tenon segment structures to achieve strong shear resistance and deformation resistance. In combination with the needle grouting method, it can effectively plug leaks. The multiple grouting shield tunnel construction method for water-rich and variable formations can effectively adapt to various water-rich and variable formations during actual operation.

[0023] 5. The present invention utilizes the needle grouting method to implement multiple grouting technology, which can gradually reinforce the stratum and solve various problems encountered in the construction of shield tunnels, such as groundwater seepage and ground subsidence. This method can effectively deal with various problems caused by changeable terrain, such as unstable strata and complex terrain, and ensure the smooth construction and long-term operation of shield tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the present invention;

[0025] Figure 2It is a schematic diagram of the three-dimensional structure of the main reinforcing bracket of the present invention;

[0026] Figure 3 It is a schematic diagram of the three-dimensional structure of the secondary reinforcing bracket of the present invention;

[0027] In the figure: 1. shield tunnel; 2. outer segment; 3. inner segment; 4. tenon structure; 5. groove; 6. waterproof pad; 7. main reinforcement bracket; 71. main reinforcement structure body; 72. side empty groove; 73. flow cavity; 74. support keel; 75. overflow hole; 76. positioning strip; 8. secondary reinforcement bracket; 81. secondary reinforcement structure body; 82. slurry flow groove; 83. support frame; 84. assembly protrusion; 85. side flow groove; 86. secondary connection hole; 87. main connection hole; 88. reinforcement rib. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] See also Figure 1-3 The present invention provides a technical solution: a waterproof and pollution-proof shield tunnel construction method under a riverbed, comprising the following steps:

[0030] Step 1: After the shield machine starts, the outer segments 2 are laid in a circular distribution in the shield tunnel 1, and the adjacent outer segments 2 are connected by a concave-convex structure and fixed and assembled by tightening bolts;

[0031] Step 2: When laying the outer tube segment 2 arranged in a circular distribution, the reserved grouting holes of the outer tube segment 2 are used to complete the grouting of the shield tunnel 1 by synchronous grouting. When the shield machine advances forward to form a gap at the shield tail, the double-pump four-pipeline grouting pipe at the shield tail is used synchronously to perform symmetrical, uniform and full grouting. The speed should match the excavation speed. The average grouting speed is determined by the amount of grouting completed in the shield within the time it takes to complete one ring of excavation. Uniform grouting is ensured. Factors such as deviation correction, slurry leakage and shrinkage of grouting materials during the advancement process are considered. The grouting amount is 1.5-2 times the theoretical volume of the shield tail control gap, that is, the grouting amount behind each ring wall is 5.5-6.5m 3 ;

[0032] Step 3: Add water-stop rings at 2 locations outside every 5 rings of segments to block the groundwater behind, reduce the waterproof pressure of the shield tunnel 1, improve the water-stop effect, and stabilize the segments; on the other hand, prevent water from the rear from entering the shield tunnel 1 during the downhill section;

[0033] Step 4: After the grouting of the shield tunnel 1 solidifies, secondary lining is carried out, the original water-stop ring is removed, and the main reinforcement bracket 7, the secondary reinforcement bracket 8 and the waterproof pad 6 are laid on the basis of the original outer segment 2. The main reinforcement bracket 7 is set at the interface, and the secondary reinforcement bracket 8 is set at other annular parts. The fixing part adopts a chimeric structure to complete the positioning, and the inner segment 3 and the outer segment 2 are fixed and assembled with bolts;

[0034] Step 5: After the assembly is completed, perform secondary grouting and add water stop rings at 3 locations within every 5 rings of segments;

[0035] Step 6: Check the leakage point and inject grout three times.

[0036] In the present invention, the outer tube segment 2 is arranged in the inner cavity of the shield tunnel 1 and is arranged in an annular distribution, the inner tube segment 3 is arranged on one side of the outer tube segment 2, and the adjacent outer tube segments 2 and the inner tube segments 3 are respectively provided with a tenon structure 4 and a groove 5 for fitting, and a waterproof pad 6 arranged in pairs is arranged between the outer tube segment 2 and the inner tube segment 3, and an assembly groove for installing the waterproof pad 6 is opened on the side opposite to the outer tube segment 2 and the inner tube segment 3, and the main reinforcement bracket 7 is arranged at the joint of the outer tube segment 2 and the inner tube segment 3, and the secondary reinforcement bracket 8 is arranged between two adjacent waterproof pads 6, and the main reinforcement bracket 7 includes a main reinforcement structure body 71, and side empty grooves 72 are opened on both sides of the top of the main reinforcement structure body 71, and a flow cavity 73 is opened on the top of the main reinforcement structure body 71, and the inner cavity of the flow cavity 73 A supporting keel 74 is fixedly connected, and a number of overflow holes 75 with equal spacing are respectively opened on both sides of the inner cavity of the flow cavity 73, and the overflow holes 75 are connected to the side empty grooves 72. Positioning strips 76 are arranged on both sides of the top of the main reinforcement structure body 71. The secondary reinforcement bracket 8 includes a secondary reinforcement structure body 81, and a slurry flow groove 82 is opened on the top of the secondary reinforcement structure body 81. The inner cavity of the slurry flow groove 82 is fixedly connected to a support frame 83, and both sides of the top and bottom of the secondary reinforcement structure body 81 are fixedly connected with assembly protrusions 84, and both sides of the top of the secondary reinforcement structure body 81 are opened. Side flow grooves 85 are opened, and secondary connecting holes 86 and main connecting holes 87 connecting the slurry flow groove 82 and the side flow grooves 85 are opened on both sides of the inner cavity of the slurry flow groove 82.

[0037] In the present invention, a reinforcing rib 88 is fixedly connected to the surface of the support frame 83, and the arrangement of the reinforcing rib 88 can greatly improve the anti-deformation capability.

[0038] In the present invention, the grouting material in step 2 is cement mortar, and its specific formula ratio is: cement: fly ash: bentonite: sand: water = 4.1: 10: 3: 3.2: 8.5.

[0039] In the present invention, the grouting material in step five is a crack-resistant, waterproof and anti-fouling mortar, and its specific formula ratio is: composite fly ash: slag powder: basalt fiber = 100:200:1.

[0040] In the present invention, the three grouting steps in step six are divided into a grouting stage and a sealing stage. The grouting stage adopts a single-liquid slurry, namely cement slurry, and the water-cement ratio is 1:1. The sealing stage adopts a double-liquid slurry, and the weight ratio of water to water glass is 3:1. The weight ratio of cement slurry to water-cement ratio is 1:1, the volume ratio of cement slurry to water glass is 1:1, and the grouting pressure is 2.5 to 3.5 bar. The grouting pressure and grouting amount are controlled to prevent the pipe segments from being squeezed out of position.

[0041] Since the longitudinal stiffness of the tunnel itself has little effect on its longitudinal deformation, measures to increase the connection stiffness between segment rings have no obvious effect on controlling deformation. The present invention adopts secondary lining technology to improve the waterproof and anti-fouling capabilities on the basis of maintaining the rigidity of the tunnel. Under different scouring conditions, the longitudinal settlement law of the tunnel across the river is the same, and the differential settlement is mainly concentrated in the transition section where the riverbed topography changes drastically. Necessary control measures are taken in the transition section. Double-channel water-stopping devices must be set at the segment joints under high-pressure and water-rich conditions. Multiple waterproof pads are used in this technical solution to solve the problem of waterproofing and anti-fouling.

[0042] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A waterproof and pollution-proof shield tunnel construction method for passing under a riverbed, characterized in that: The steps include: Step 1: After the shield machine is started, the outer segments (2) are laid in a circular distribution in the shield tunnel (1), and the adjacent outer segments (2) are connected by a concave-convex structure and fixedly assembled by tightening bolts; Step 2: When laying the outer pipe segments (2) arranged in an annular distribution, the reserved grouting holes of the outer pipe segments (2) are used to complete the grouting of the shield tunnel (1) by synchronous grouting. When the shield machine advances forward to form a gap at the shield tail, the double-pump four-pipeline grouting pipe at the shield tail is used synchronously to perform symmetrical, uniform and full grouting. The speed should match the excavation speed. The average grouting speed is determined by the amount of grouting completed in the shield within the time it takes to complete one ring of excavation. Uniform grouting is ensured. Factors such as deviation correction, grouting leakage and shrinkage of grouting materials during the advancement process are taken into consideration. The grouting amount is 1.5-2 times the theoretical volume of the shield tail control gap, that is, the grouting amount behind each ring wall is 5.5-6.5m 3 ; Step 3: Add water-stop ring hoops at every 5 rings of the outer pipe segment (2) to block the groundwater at the rear, reduce the waterproof pressure of the shield tunnel (1), improve the water-stopping effect, and stabilize the pipe segment; on the other hand, in the downhill section, prevent the water from the rear from entering the shield tunnel (1); Step 4: After the grouting of the shield tunnel (1) solidifies, secondary lining is carried out, the original water-stop ring is removed, and the main reinforcement bracket (7), the secondary reinforcement bracket (8) and the waterproof pad (6) are laid on the basis of the original outer tube segment (2), the main reinforcement bracket (7) is arranged at the interface, and the secondary reinforcement bracket (8) is arranged at other annular parts. The fixing part adopts a chimeric structure to complete the positioning, and the inner tube segment (3) and the outer tube segment (2) are fixed and assembled using bolts; Step 5: After the assembly is completed, secondary grouting is performed, and a water stop ring hoop is added at every 5 rings of the inner segment (3); Step 6: Check the leakage point and inject grout three times.

2. A waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 1, characterized in that: The outer tube segment (2) is arranged in the inner cavity of the shield tunnel (1) and is arranged in an annular distribution. The inner tube segment (3) is arranged on one side of the outer tube segment (2). A tenon structure (4) and a groove (5) for engagement are respectively arranged between adjacent outer tube segments (2) and inner tube segments (3). Paired waterproof pads (6) are arranged between the outer tube segment (2) and the inner tube segment (3). An assembly groove for installing the waterproof pad (6) is provided on the side of the outer tube segment (2) opposite to the inner tube segment (3). The main reinforcement bracket (7) is arranged at the joint between the outer tube segment (2) and the inner tube segment (3). The secondary reinforcement bracket (8) is arranged between two adjacent waterproof pads (6).

3. A waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 2, characterized in that: The main reinforcement bracket (7) comprises a main reinforcement structure body (71), side hollow grooves (72) are provided on both sides of the top of the main reinforcement structure body (71), a flow cavity (73) is provided on the top of the main reinforcement structure body (71), the inner cavity of the flow cavity (73) is fixedly connected to a supporting keel (74), a plurality of overflow holes (75) distributed at equal intervals are provided on both sides of the inner cavity of the flow cavity (73), the overflow holes (75) are connected to the side hollow grooves (72), and positioning strips (76) are provided on both sides of the top of the main reinforcement structure body (71).

4. The waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 1, characterized in that: The secondary reinforcement bracket (8) comprises a secondary reinforcement structure body (81), a slurry flow groove (82) is provided on the top of the secondary reinforcement structure body (81), a support frame (83) is fixedly connected to the inner cavity of the slurry flow groove (82), assembly protrusions (84) are fixedly connected to both sides of the top and bottom of the secondary reinforcement structure body (81), side flow grooves (85) are provided on both sides of the top of the secondary reinforcement structure body (81), and secondary connection holes (86) and main connection holes (87) that connect the slurry flow groove (82) and the side flow groove (85) are provided on both sides of the inner cavity of the slurry flow groove (82).

5. The waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 4, characterized in that: A reinforcing rib (88) is fixedly connected to the surface of the support frame (83).

6. The waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 1, characterized in that: The grouting material in step 2 is cement mortar, and its specific formula ratio is: cement: fly ash: bentonite: sand: water = 4.1:10:3:3.2:8.

5.

7. The waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 1, characterized in that: The grouting material in step five is a crack-resistant, waterproof and anti-fouling mortar, and its specific formula ratio is: composite fly ash: slag powder: basalt fiber = 100:200:

1.

8. The waterproof and pollution-proof shield tunnel construction method for passing under a riverbed according to claim 1, characterized in that: The three grouting steps in step six are divided into the grouting stage and the sealing stage. The grouting stage uses single-liquid slurry, namely cement slurry, with a water-cement ratio of 1:1; the sealing stage uses double-liquid slurry, with a water-water glass weight ratio of 3:1; the weight ratio of cement slurry to water-cement ratio is 1:1, and the volume ratio of cement slurry to water glass is 1:

1. The grouting pressure is 2.5 to 3.5 bar. The grouting pressure and grouting amount are controlled to prevent the pipe segments from being squeezed out of position.

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