Steel structure reinforcing and grouting reinforcing method for shield small-clear-distance underneath passing existing line under water-rich sand layer condition

Abstract

The invention discloses steel structure reinforcement for shield small-clear-distance underneath passing of an existing line under the condition of a water-rich sand layer, which comprises a steel ring, an anti-mud-effect grouting hole, a soil body-shield body building gap, a synchronous grouting pipeline, a soil body-segment outer surface building gap and a segment secondary grouting hole site, the steel ring comprises a first steel ring sub-block, a second steel ring sub-block, a third steel ring sub-block, a fourth steel ring sub-block, a fifth steel ring sub-block and a sixth steel ring sub-block. Through the steel ring and brace structure and in combination with the processes of epoxy resin bonding, chemical anchor bolt connection, welding and the like, the strength and integrity of the existing line segment are improved, and the risks of segment floating and cracking possibly caused by segment back grouting reinforcement are avoided; grouting reinforcement is carried out in a shield interval, so that the self-stabilization capability of a stratum is improved, differential settlement is reduced, and the influence of shield underneath pass tunneling construction on normal operation of an existing line is avoided; the material source is wide, the operability is high, and the actual benefit is remarkable.

Description

Technical Field

[0001] The present invention relates to the field of tunnel construction, and in particular to a steel structure reinforcement and grouting reinforcement method for a shield machine passing through an existing line with a small clearance under water-rich sand layer conditions. Background Art

[0002] In urban rail transit construction, shield tunnel construction often needs to pass through complex geological conditions, such as water-rich sand layers. Water-rich sand layers have the characteristics of high permeability and high sensitivity, and are prone to uneven settlement and even sand and water gushing during shield construction. Therefore, when passing under existing lines with a small clearance under water-rich sand layers, how to ensure the safety of the existing lines and the smooth progress of shield construction is a technical problem that needs to be solved urgently. Existing reinforcement methods such as ground sleeve valve pipe tracking grouting and shield advance grouting technology have certain limitations, such as limited reinforcement range, narrow construction space, and difficult hole layout, which are difficult to meet the construction requirements of passing under existing lines with a small clearance under water-rich sand layers. Therefore, a new reinforcement method is needed to solve these problems. Summary of the Invention

[0003] The purpose of the present invention is to provide a steel structure reinforcement and grouting reinforcement method for a shield machine passing through an existing line with a small clearance under water-rich sand layer conditions, so as to solve the problems raised in the above background technology.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a steel structure reinforcement for a shield tunnel under a small clearance under water-rich sand layer conditions, comprising a steel ring, a mud-reducing effect grouting hole, a soil-shield building gap, a synchronous grouting pipeline, a soil-segment outer surface building gap and a segment secondary grouting hole position, the steel ring comprising a first steel ring block, a second steel ring block, a third steel ring block, a fourth steel ring block, a fifth steel ring block and a sixth steel ring block, the first steel ring block, the second steel ring block, the third steel ring block, the fourth steel ring block, the fifth steel ring block and the sixth steel ring block are welded and fixed to form a ring-shaped steel ring, the inner side of the steel ring An original roadbed is provided, a corbel bracket is provided on one side of the steel ring, an existing inner pipeline is provided on the inner side of the steel ring, a chemical anchor is provided on one side of the steel ring, a steel ring bolt hole is provided on the outer side of the steel ring, a steel ring reserved grouting hole is provided on the outer side of the steel ring, a pull rod is provided on the inner side of the steel ring, epoxy resin is cast on one side of the steel ring, the mud effect grouting hole is provided inside the covering soil, the soil-shield construction gap is located between the hard soil and the covering soil, the synchronous grouting pipeline is provided inside the covering soil, the soil-segment outer surface construction gap is provided at the lower end of the covering soil, and the segment secondary grouting hole is provided on the segment outside the steel ring.

[0005] As a further improvement of the present invention, the pull rod includes a first steel pull rod, a second steel pull rod, a steel pull rod bolt hole, a reinforcing steel plate and a weld. The weld is arranged at the center position of the reinforcing steel plate to facilitate welding and connecting the reinforcing steel plate. The steel pull rod bolt holes are opened on both sides of the first steel pull rod, both sides of the second steel pull rod and both sides of the reinforcing steel plate. When in use, the first steel pull rod and the second steel pull rod are fixed to both sides of the reinforcing steel plate through the steel pull rod bolt holes and fixing bolts. In this way, the pull rod is composed of the first steel pull rod, the second steel pull rod, the steel pull rod bolt hole, the reinforcing steel plate and the weld.

[0006] A method for grouting and reinforcing a steel structure under a water-rich sand layer with a shield machine passing through an existing line with a small clearance, specifically comprising the following steps:

[0007] (1) Reinforcement of the existing line steel structure refers to the installation of steel rings at the annular joints of the existing line segments and the installation of five long tie rods along the axial direction of the steel rings. Before installation, it is necessary to relocate the water and electricity pipelines in the existing line segments and complete the cutting and removal of the original roadbed in some locations.

[0008] (2) Select a location on the pipe segment that does not contain steel bars and grouting holes, drill holes and install chemical anchor bolts according to the installation requirements of the tie rods and steel rings.

[0009] (3) The tie bars are arranged axially along the existing tunnel, with five long tie bars distributed circumferentially. The tie bars are connected axially by welding and connected to the segments by bolts and anchors. At the circumferential joints of the segments, the tie bars need to be cut according to the steel ring installation requirements, and the cut positions are reinforced by adding strengthening steel plates.

[0010] (4) The steel rings are also assembled by welding and anchoring, and epoxy resin is injected through the reserved grouting holes on the steel rings. Before construction, the epoxy bonding parts on the pipe segments need to be roughened and cleaned.

[0011] (5) The steel ring and the tie rod are connected by full welding process, and the channel steel is welded on the steel ring to connect with the tie rod.

[0012] (6) Shield tunneling interval grouting reinforcement refers to the process of completing the shield tunneling under the existing line with a small clear distance through the use of mud-reducing grouting, synchronous grouting and secondary grouting reinforcement methods during the process of underpassing the existing line.

[0013] As a further improvement of the method of the present invention, in step (1), the steel ring is 600 mm wide, 45 mm thick, and made of Q345B. It is divided into 6 pieces along the circumferential direction. If a complex position of the pipeline is encountered, it is divided into 7 pieces, namely, two brackets at the bottom, three to four ring plates at the top, and a top plate; the pull rod is 16b hot-rolled channel steel, made of Q235B, and the length of a single section of channel steel along the axial direction is about 4 m.

[0014] As a further improvement of the method of the present invention, in step (2), the drilling and installation of chemical anchors include setting out, arranging points and completing the drilling work.

[0015] As a further improvement to the method of the present invention, in step (3), the pull rods are circumferentially distributed, with two on the arch top, one on the arch side with the drainage pipeline, and two on the arch side without the drainage pipeline, and are relatively evenly distributed.

[0016] As a further improvement to the method of the present invention, in step (4), the epoxy resin grouting is the epoxy resin injection filling work between the annular steel plate and the pipe segment after the steel ring is installed. No less than four grouting holes and air outlet holes are reserved on each steel plate. The grouting pressure is not greater than 0.3 MPa. Grouting is stopped when the gap between the steel ring and the pipe segment is filled.

[0017] As a further improvement of the method of the present invention, in step (6), the grouting with the sludge effect needs to be supplemented with a sludge effect grouting machine at an appropriate position in the supporting trolley behind the shield, and the grouting pipeline is connected to the sludge effect grouting channel at the shield in the middle of the shield. The grouting slurry is AB double liquid, liquid A is a sludge effect aqueous solution, and liquid B is water glass. The coagulation time of the double liquid mixed reaction shall not exceed 20s, and the viscosity shall not be less than 300dPa·s; the synchronous grouting needs to be completed by the synchronous grouting equipment supporting the shield machine, using cement mortar containing bentonite, the consistency of which is preferably 10~12.5cm, the initial setting time is not more than 6 hours, and the 28d strength under standard curing conditions is greater than 1MPa; the secondary grouting needs to first make uniform holes on the shield segment, and evenly inject AB double liquid through the secondary grouting machine, liquid A is cement slurry, and liquid B is water glass. The grouting pressure is generally not more than 0.5MPa.

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

[0019] The present invention improves the strength and integrity of the existing line segments through the steel ring and tie rod structure, combined with epoxy resin bonding, chemical anchor connection and welding processes, and avoids the risk of segment floating and cracking caused by grouting reinforcement behind the segments; by performing grouting reinforcement in the shield interval, the self-stabilization ability of the stratum is improved, uneven settlement is reduced, and the impact of shield underpass excavation construction on the normal operation of the existing line is avoided; the present invention has a wide range of material sources, strong operability, and significant practical benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the technical roadmap of the present invention.

[0021] Figure 2 It is a schematic diagram of the steel ring blocks of the present invention.

[0022] Figure 3 It is a schematic diagram of the track bed corbel bracket of the present invention.

[0023] Figure 4 It is a schematic diagram of fixing the steel ring of the present invention.

[0024] Figure 5 Schematic diagram of the steel rod of the present invention.

[0025] Figure 6 This is a schematic diagram of fixing the steel pull rods of the present invention.

[0026] Figure 7 This is a schematic diagram of the steel ring-steel tie rod interaction point fixation of the present invention.

[0027] Figure 8 It is a schematic diagram of the mud-reducing effect grouting and synchronous grouting of the present invention.

[0028] Figure 9 This is a schematic diagram of the secondary grouting hole position of the present invention.

[0029] Marking instructions: 1. Steel ring; 1-1. First steel ring block; 1-2. Second steel ring block; 1-3. Third steel ring block; 1-4. Fourth steel ring block; 1-5. Fifth steel ring block; 1-6. Sixth steel ring block; 2. Original roadbed; 3. Existing pipeline within the line; 4. Corbel bracket; 5. Chemical anchor; 6. Steel ring bolt hole; 7. Steel ring reserved grouting hole; 8. Tie rod; 8-1 First steel tie rod; 8-2. Second steel tie rod; 9. Steel tie rod bolt hole; 10. Reinforced steel plate; 11. Weld; 12. Epoxy resin; 13. Mud-reducing grouting hole; 14. Gap between soil and shield structure; 15. Synchronous grouting pipeline; 16. Gap between soil and outer surface of segment; 17. Secondary grouting hole position of segment. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0031] See also Figure 1-9The present invention provides a technical solution: a steel structure reinforcement for a shield tunnel under a water-rich sand layer with a small clearance under an existing line, comprising a steel ring 1, a mud-reducing effect grouting hole 13, a soil-shield building gap 14, a synchronous grouting pipeline 15, a soil-segment outer surface building gap 16 and a segment secondary grouting hole position 17, wherein the steel ring 1 comprises a first steel ring block 1-1, a second steel ring block 1-2, a third steel ring block 1-3, a fourth steel ring block 1-4, a fifth steel ring block 1-5 and a sixth steel ring block 1-6, wherein the first steel ring block 1-1, the second steel ring block 1-2, the third steel ring block 1-3, the fourth steel ring block 1-4, the fifth steel ring block 1-5 and the sixth steel ring block 1-6 are welded and fixed to form a ring-shaped steel ring 1. The original roadbed 2 is provided on the inner side of the steel ring 1, a corbel bracket 4 is provided on one side of the steel ring 1, an existing inner pipeline 3 is provided on the inner side of the steel ring 1, a chemical anchor 5 is provided on one side of the steel ring 1, a steel ring bolt hole 6 is provided on the outer side of the steel ring 1, a steel ring reserved grouting hole 7 is provided on the outer side of the steel ring 1, a pull rod 8 is provided on the inner side of the steel ring 1, epoxy resin 12 is cast on one side of the steel ring 1, the mud effect grouting hole 13 is opened inside the covering soil, the soil-shield building gap 14 is located between the hard soil and the covering soil, the synchronous grouting pipeline 15 is opened inside the covering soil, the soil-segment outer surface building gap 16 is opened at the lower end of the covering soil, and the segment secondary grouting hole 17 is opened on the segment outside the steel ring 1.

[0032] The pull rod 8 includes a first steel pull rod 8-1, a second steel pull rod 8-2, a steel pull rod bolt hole 9, a reinforcing steel plate 10 and a weld 11. The weld 11 is arranged at the center of the reinforcing steel plate 10 to facilitate welding and connecting the reinforcing steel plate 10. The steel pull rod bolt holes 9 are opened on both sides of the first steel pull rod 8-1, both sides of the second steel pull rod 8-2 and both sides of the reinforcing steel plate 10. When in use, the first steel pull rod 8-1 and the second steel pull rod 8-2 are fixed to both sides of the reinforcing steel plate 10 through the steel pull rod bolt holes 9 in combination with the fixing bolts. In this way, the pull rod 8 is composed of the first steel pull rod 8-1, the second steel pull rod 8-2, the steel pull rod bolt hole 9, the reinforcing steel plate 10 and the weld 11.

[0033] A method for grouting and reinforcing a steel structure under a water-rich sand layer with a shield machine passing through an existing line with a small clearance, specifically comprising the following steps:

[0034] (1) Preparation

[0035] First, the existing pipeline 3 that affects the installation of the steel ring is relocated, and the original roadbed 2 where the steel ring is installed is partially cut, polished, roughened and cleaned. The cutting width should not be less than the actual width of the bracket 4 to meet the assembly requirements.

[0036] Subsequently, based on the design drawings and equipment such as a rebar detector, a location without rebar or grouting holes was selected on the existing segment. Referring to the assembly requirements of the tie bars 8 and the steel ring 1, holes were drilled on the segment and chemical anchor bolts 5 were installed. The chemical anchor bolts 5 used M30 bolts and were inserted into the concrete to a depth of no less than 160mm.

[0037] (2) Installation of steel tie bars

[0038] The brace 8 is arranged along the axial direction of the existing tunnel. Figure 5 As shown, five long tie bars 8 are distributed in the circumferential direction, and their installation range should cover the area affected by the shield tunneling construction; the tie bars 8 are 16b hot-rolled channel steel, made of Q235B, and the length of a single channel steel along the axial direction is about 4m; Figure 6 As shown, each section of channel steel is connected by welding, and a reinforcing steel plate 10 is added to reinforce the weld 11 at the welding position.

[0039] When the brace 8 and the steel ring 1 are Figure 7 At the spatial interaction point shown, the brace 8 needs to be cut according to the installation requirements of the steel ring 1, and the cutting position is reinforced by adding a strengthening steel plate 10;

[0040] (3) Steel ring installation

[0041] The steel ring 1 is 600mm wide and 45mm thick, made of Q345B. It is divided into 6 parts along the circumferential direction. If it encounters a complex position in the pipeline, it is divided into 7 parts, namely the first steel ring part 1-1 and the sixth steel ring part 1-6 at the bottom, the second steel ring part 1-2, the fourth steel ring part 1-4 and the fifth steel ring part 1-5 of the upper three to four ring plates, and the third steel ring part 1-3 of the top plate.

[0042] The steel ring 1 is assembled and connected to the pipe segment through the reserved steel ring bolt holes 6, and epoxy resin 12 is injected through the reserved grouting holes 7 of the steel ring; the steel ring 1 and the tie rod 8 are welded at the welding position 11 using a full welding process, and the channel steel is welded on the steel ring 1 to connect with the tie rod 8;

[0043] When injecting epoxy resin 12, the grouting pressure is not greater than 0.3 MPa, and the grouting is stopped when the gap between the steel ring 1 and the segment is filled;

[0044] (4) Grouting reinforcement of shield tunnel sections

[0045] The diameter of the shield cutterhead is slightly larger than the outer diameter of the shield. During the construction process, there will be Figure 8As shown, the gap 14 between the soil and the shield structure is filled by adding a grouting machine at an appropriate position in the supporting trolley behind the shield. The grouting hole 13 reserved in the middle shield is used to inject grouting liquid into the gap 14 between the soil and the shield structure. The grouting liquid is a double liquid AB solution, where liquid A is a grouting water solution and liquid B is water glass. The coagulation time of the mixed reaction of the two liquids shall not exceed 20 seconds, and the viscosity shall not be less than 300 dPa·s.

[0046] When the shield tail moves forward, it will produce Figure 8 The gap 16 between the soil and the outer surface of the segment is filled with synchronous grouting slurry through the synchronous grouting equipment provided by the shield machine and the reserved synchronous grouting pipeline 15 of the shield machine. The grouting slurry uses a cement mortar containing bentonite, with a consistency of 10-12.5 cm, an initial setting time of no more than 6 hours, and a 28-day strength under standard curing conditions greater than 1 MPa.

[0047] When the shield machine leaves the segment, in order to suppress the adverse deformation such as creep settlement of the water-rich sand layer, secondary grouting is required behind the assembled segment. First, the shield segment is grouting. Figure 9 The uniform opening shown is evenly injected with AB double liquids through a secondary grouting machine. Liquid A is cement slurry and liquid B is water glass. The grouting pressure is generally not more than 0.5MPa.

[0048] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0049] While 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 these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A steel structure reinforcement for a shield tunnel under a water-rich sand layer with a small clearance under an existing line, comprising a steel ring (1), a mud-reducing grouting hole (13), a soil-shield structure gap (14), a synchronous grouting pipeline (15), a soil-segment outer surface structure gap (16), and a segment secondary grouting hole (17), characterized in that: The steel ring (1) comprises a first steel ring segment (1-1), a second steel ring segment (1-2), a third steel ring segment (1-3), a fourth steel ring segment (1-4), a fifth steel ring segment (1-5) and a sixth steel ring segment (1-6); the first steel ring segment (1-1), the second steel ring segment (1-2), the third steel ring segment (1-3), the fourth steel ring segment (1-4), the fifth steel ring segment (1-5) and the sixth steel ring segment (1-6) are welded and fixed to form a ring-shaped steel ring (1); an original roadbed (2) is provided on the inner side of the steel ring (1); a bracket support (4) is provided on one side of the steel ring (1); and an existing inner pipe is provided on the inner side of the steel ring (1). A line (3) is provided on one side of the steel ring (1), a chemical anchor bolt (5) is provided on the outside of the steel ring (1), a steel ring bolt hole (6) is provided on the outside of the steel ring (1), a steel ring reserved grouting hole (7) is provided on the outside of the steel ring (1), a tie rod (8) is provided on the inside of the steel ring (1), epoxy resin (12) is poured on one side of the steel ring (1), the mud effect grouting hole (13) is provided inside the covering soil, the soil-shield building gap (14) is located between the hard soil and the covering soil, the synchronous grouting pipeline (15) is provided inside the covering soil, the soil-segment outer surface building gap (16) is provided at the lower end of the covering soil, and the segment secondary grouting hole (17) is provided on the segment outside the steel ring (1).

2. The steel structure reinforcement for shield tunneling under existing lines with a small clearance under water-rich sand conditions according to claim 1 is characterized by: The tie rod (8) comprises a first steel tie rod (8-1), a second steel tie rod (8-2), a steel tie rod bolt hole (9), a reinforcing steel plate (10) and a weld (11). The weld (11) is arranged at the center of the reinforcing steel plate (10) to facilitate welding and connecting the reinforcing steel plate (10). The steel tie rod bolt hole (9) is opened on both sides of the first steel tie rod (8-1), on both sides of the second steel tie rod (8-2) and on both sides of the reinforcing steel plate (10).

3. A method for grouting and reinforcing a steel structure under a water-rich sand layer with a shield tunnel under a small clearance, characterized by: The specific steps include: (1) Strengthening the steel structure of an existing line refers to installing a steel ring (1) at the annular joint of the pipe segment (3) of the existing line, and installing five long tie bars (8) along the axial direction of the steel ring (1); before installation, it is necessary to first relocate the water and electricity pipelines in the pipe segment (3) of the existing line, and complete the cutting and chiseling of the original roadbed (2) at some locations; (2) Select a location on the segment that does not contain steel bars and grouting holes, drill holes and install chemical anchor bolts (5) according to the installation requirements of the tie rods (8) and steel rings (1); (3) The tie bars (8) are arranged axially along the existing tunnel, with five long tie bars (8) distributed circumferentially. The tie bars (8) are connected axially by welding, and are connected to the segments by bolting and anchoring. At the segment circumferential joints, the tie bars (8) need to be cut in accordance with the installation requirements of the steel ring (1), and the cut positions are reinforced by adding strengthening steel plates (10). (4) The steel ring (1) is also assembled by welding and bolting, and epoxy resin (12) is injected through the reserved grouting hole (7) on the steel ring (1). Before construction, the epoxy bonding part on the pipe segment needs to be roughened and cleaned; (5) The steel ring (1) and the tie rod (8) are connected by a full welding process, and the channel steel is welded on the steel ring (1) to connect with the tie rod (8); (6) Shield tunneling interval grouting reinforcement refers to the process of completing the shield tunneling under the existing line with a small clear distance through the use of mud-reducing grouting, synchronous grouting and secondary grouting reinforcement methods during the process of underpassing the existing line.

4. The method for grouting and reinforcing a steel structure under a water-rich sand layer under a shield tunnel with a small clearance under an existing line according to claim 3, characterized in that: In step (1), the steel ring 1 is 600 mm wide, 45 mm thick, and made of Q345B. It is divided into (6) pieces along the annular direction. If it encounters a complex position of the pipeline, it is divided into (7) pieces, namely two brackets (4) at the bottom, three to four ring plates at the top, and a top plate; the pull rod (8) is 16b hot-rolled channel steel, made of Q235B, and the length of a single section of channel steel along the axial direction is about 4 m.

5. The method for grouting and reinforcing a steel structure under a water-rich sand layer under a shield tunnel with a small clearance under an existing line according to claim 4, characterized in that: In step (2), the drilling and installation of chemical anchor bolts (5) include setting out, arranging points and completing the drilling work.

6. The method for grouting and reinforcing a steel structure under a water-rich sand layer under conditions of claim 5, characterized in that: In step (3), the pull strips (8) are distributed circumferentially, with two on the arch top, one on the arch side with the drainage pipeline, and two on the arch side without the drainage pipeline, and are relatively evenly distributed.

7. The method for grouting and reinforcing a steel structure under a water-rich sand layer under a shield tunnel with a small clearance under an existing line according to claim 6, characterized in that: In step (4), the epoxy resin (12) grouting is the epoxy resin (12) pressure injection filling work between the annular steel plate (1) and the pipe segment after the steel ring (1) is installed. No less than four grouting holes and air outlet holes are reserved on each steel plate. The grouting pressure is not greater than 0.3 MPa. Grouting is stopped when the gap between the steel ring (1) and the pipe segment is filled.

8. The method for grouting and reinforcing a steel structure under a water-rich sand layer under a shield tunnel with a small clearance under an existing line according to claim 7, characterized in that: In step (6), the grouting with sludge effect requires adding a sludge effect grouting machine at an appropriate position in the supporting trolley behind the shield, and connecting the grouting pipeline to the sludge effect grouting hole (13) at the shield center of the shield. The grouting slurry is AB double liquid, liquid A is a sludge effect aqueous solution, and liquid B is water glass. The coagulation time of the double liquid mixed reaction shall not exceed 20s, and the viscosity shall not be less than 300dPa·s; the synchronous grouting needs to be completed by the synchronous grouting equipment equipped with the shield machine, using cement mortar containing bentonite, the consistency of which should be 10~12.5cm, the initial setting time should not be more than 6 hours, and the 28d strength under standard curing conditions should be greater than 1MPa; the secondary grouting needs to first make uniform holes on the shield segment, and evenly inject AB double liquid through the secondary grouting machine, liquid A is cement slurry, and liquid B is water glass. The grouting pressure is generally not more than 0.5MPa.

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