Shield tunnel prefabricated assembly comprehensive pipe gallery internal structure and construction method

Abstract

The present application relates to a shield tunnel prefabricated assembly comprehensive pipe gallery internal structure and construction method, comprising the following steps: step one, construction preparation; step two, shield segment internal chiseling, planting root treatment; step three, cast-in-place base pouring; step four, prefabricated arc wall assembly; step five, installation of mold, stop grout pad; step six, prefabricated partition wall assembly; step seven, prefabricated arc wall planting root; step eight, prefabricated arc wall back grouting; step nine, reserved sleeve grouting connection; step ten, set up partition plate formwork support; step eleven, binding partition plate reinforcement. The present application sets up edge ribbed slab on both sides of cast-in-place partition plate, sets up central ribbed slab in the middle, and the partition plate reinforcement, prefabricated base reserved reinforcement and prefabricated partition wall reserved reinforcement are welded as a whole, which improves the integrity of the cast-in-place partition plate and the prefabricated base and prefabricated partition wall connection, and solves the problem of weak connection of cast-in-place partition plate and supporting structure.

Description

Technical Field

[0001] This invention relates to the internal structure and construction method of prefabricated integrated utility tunnels in shield tunnels. It is mainly applicable to the installation of prefabricated integrated utility tunnels in ordinary large shield tunnels for the routing of high-voltage cables, drainage pipes, and municipal integrated equipment pipelines. It can also be used in the construction of urban subway stations, pedestrian utility tunnels, and highway tunnel utility tunnels. Background Technology

[0002] Currently, urban road tunnel construction in my country is developing rapidly, evolving from small-diameter to large-diameter tunnels, from short to long tunnels, from single-layer to double-layer tunnels, and from cast-in-place to prefabricated tunnels. Especially in first-tier cities, where underground space resources are limited, the construction of large-diameter, double-layer internal structure shield tunnels is increasingly common to make full use of the tunnel's internal space. However, due to the limited internal space and complex double-layer internal structure, traditional cast-in-place construction methods present numerous inconveniences for the construction of the double-layer internal structure. With the development and maturation of prefabricated construction, this problem can be effectively solved, allowing for simultaneous construction of the internal structure and shield tunneling, thus saving construction time.

[0003] There are still some problems in the construction of the prefabricated double-layer internal structure of shield tunnel: (1) The connection between the prefabricated arc wall and the shield segment, and between the prefabricated arc wall, the prefabricated middle partition wall and the base is not firm. During long-term use, the prefabricated arc wall and the prefabricated middle partition wall are prone to loosening due to long-term vibration caused by human and vehicle, which affects the safety of use; (2) The installation positioning accuracy of the prefabricated middle partition wall is poor, the installation efficiency is low, and the time is long; (3) The effective contact surface between the middle partition and the lower support structure is small, and the overall connection between the two is not strong. Due to the narrow space, it is difficult to support the formwork at the corners and edges. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies and provide an internal structure and construction method for a prefabricated integrated utility tunnel in a shield tunnel.

[0005] The objective of this invention is achieved through the following technical solution: a construction method for the internal structure of a prefabricated integrated utility tunnel in a shield tunnel, comprising the following steps:

[0006] Step 1: Construction Preparation; Step 2: Roughening and rebar installation inside the tunnel lining segments; Step 3: Casting the base in place; According to the measurement and layout position, first pour an arc-shaped pad layer on the bottom inner side of the shield tunnel segment, tie the base reinforcement on the arc-shaped pad layer, weld the positioning steel plate on the base reinforcement according to the design position, and then weld the pre-embedded reinforcement through the reserved reinforcement hole on the positioning steel plate to the base reinforcement; then set up the formwork for the cast-in-place base and pour the concrete for the cast-in-place base; the two sides of the cast-in-place base form a tongue and groove with the shield tunnel segment; Step 4: Assemble the precast curved wall: Install the precast curved wall segments in sections to form the precast curved wall; install the precast base on top of the precast curved wall; Step 5: Install the sealing mold and grout stop gasket; Step Six: Assemble the prefabricated partition wall; Step 7: Rebar installation for precast curved walls; Step 8: Grouting behind the precast curved wall; Step 9: Grouting connection of the reserved sleeve; Step 10: Erect the formwork support for the middle partition: Lay a support pad on the top of the cast-in-place base, erect uprights and horizontal bars above the support pad, install U-shaped brackets on the top of the uprights, place the top horizontal main ribs on the U-shaped brackets, and install secondary ribs and formwork in sequence on the top horizontal main ribs. Step 11: Tie the reinforcing bars of the central diaphragm: The top of the prefabricated partition wall and the prefabricated base is roughened. The partition wall reinforcement is tied in the template. The partition wall reinforcement is then welded to the base reinforcement reserved on the prefabricated base and the partition wall reinforcement reserved on the top of the prefabricated partition wall. Step 12: Pour the concrete for the middle partition.

[0007] As a preferred option, the specific method for step two is as follows: roughen the contact surface between the shield tunnel segment and the precast curved wall, and use an impact drill to drill vertical holes in the shield tunnel segment along the rebar installation position to obtain the rebar installation holes. The diameter of the rebar installation hole is 4-10mm larger than the diameter of the rebar, and the depth of the rebar installation hole is 10-15 times the diameter of the rebar. Use a brush and compressed air to repeatedly clean the dust on the hole wall.

[0008] As a preferred embodiment, in step four, the precast base and the top of the precast curved wall are connected by an interlocking structure, and high-strength mortar is poured into the gap at the connection point for anchoring.

[0009] Preferably, a positioning buffer airbag is installed on the back of the precast curved wall segment; a storage groove is provided at each of the four corners of the back of the precast curved wall segment, and the positioning buffer airbag is placed in the storage groove; one end of the positioning buffer airbag is connected to the bottom of the storage groove, and the other end of the positioning buffer airbag is provided with a base plate; several exhaust ports are arranged on the side of the positioning buffer airbag near the base plate. The positioning buffer airbag has a corrugated pipe structure; a guide post is provided on the base plate, and a guide hole corresponding to the guide post is provided on the precast curved wall segment; the guide post and the guide hole are slidably engaged; the expansion and contraction direction of the positioning buffer airbag is constrained by the engagement of the guide post and the guide hole. Before hoisting the precast curved wall segment, the placement buffer airbag is first stretched to its longest state, so that the placement buffer airbag is higher than the storage groove. During the installation and placement of the precast curved wall segment, the bottom plate of one end of the placement buffer airbag contacts the inner side of the shield segment. The placement buffer airbag is compressed, causing the air inside the placement buffer airbag to be discharged outward through the exhaust port. During this process, the gradual contraction of the placement buffer airbag buffers the placement of the precast curved wall segment, reducing the impact between the precast curved wall segment and the inner side of the shield segment. At the same time, the air inside the placement buffer airbag is discharged to the side of the placement buffer airbag through the exhaust port. The airflow blown out through the exhaust port can blow towards the inner surface of the shield segment, which can remove dust from the inner surface of the shield segment. When grouting is performed between the precast curved wall and the shield segment laterally, it can make the grouting material better bond with the inner surface of the shield segment.

[0010] As a preferred option, the specific method for step five is as follows: After the cast-in-place base concrete reaches the designed strength, a grout-stopping pad is set on the top of the cast-in-place base, the pre-embedded reinforcement bars on the cast-in-place base pass through the grout-stopping pad, and a sealing mold is set around the area of ​​the precast partition wall to be installed on the top of the cast-in-place base.

[0011] As a preferred method, the specific method for step six is ​​as follows: hoist the prefabricated partition wall segments in sections, align the reserved sleeve at the bottom of the lowest prefabricated partition wall segment with the pre-embedded reinforcement bar on the cast-in-place base, and slowly lower the prefabricated partition wall segment so that the pre-embedded reinforcement bar is inserted into the reserved sleeve. The lower part of the reserved sleeve is sealed by a grout-stopping gasket. The prefabricated partition wall segments are assembled sequentially from bottom to top to obtain the prefabricated partition wall.

[0012] As a preferred method, the specific method of step seven is as follows: slowly inject the anchoring adhesive into the pre-set rebar hole of the precast curved wall, and fill the anchoring adhesive to 2 / 3 of the depth of the anchoring hole on the shield segment. Insert the anchoring bar into the pre-set rebar hole of the precast curved wall, and insert the anchoring bar into the bottom of the hole of the shield segment while rotating it to ensure that the adhesive is evenly coated.

[0013] As a preferred method, the specific method for step eight is as follows: After the precast curved wall is assembled, a 30mm wide gap is formed between the precast curved wall and the shield tunnel segment. C40 self-compacting high-strength cement-based grout is filled into this gap. When filling the C40 self-compacting high-strength cement-based grout, grouting is performed from bottom to top. Grouting pipes are pre-installed on the precast curved wall segment, including bottom grouting pipes and middle grouting pipes. Grouting begins from the bottom grouting pipe on the precast curved wall segment. When grout overflows from the middle grouting pipe on the precast curved wall segment, the bottom grouting pipe is sealed. Grouting continues from the middle grouting pipe on the precast curved wall segment until grout overflows from the pre-installed rebar holes at the top of the precast curved wall segment. Finally, the pre-installed rebar holes are sealed, thus completing the grouting operation for this unit. Then, the grouting operation for the next unit is continued. High-strength mortar is injected into the tongue and groove joint where the precast curved wall connects to the cast-in-place base for sealing. The specific method for step nine is as follows: Use a grouting machine to inject special mortar from the grout inlet pipe at the bottom of the reserved sleeve. When the grout overflows from the grout outlet pipe at the top of the reserved sleeve and there are no air bubbles, block the grout outlet pipe. The grouting pressure is 0.2-0.3 N / mm². After all grout outlet pipes are blocked, grouting and pressure holding are carried out for a period of not less than 1 minute. At the same time, high-strength mortar is injected into the gaps between adjacent grout stop pads, and high-strength mortar is injected around the perimeter of the precast partition wall and between the formwork.

[0014] Preferably, in step ten, secondary ribs and first vertical main ribs are arranged sequentially on the back of the template located on the side of the edge rib. The first vertical main rib is tightened by horizontal bars and the top transverse main rib. Secondary ribs and second vertical main ribs are arranged sequentially on the back of the L-shaped template located on both sides of the central rib. The second vertical main ribs on both sides are tightened by tie rods.

[0015] The internal structure of the prefabricated integrated utility tunnel in the shield tunnel is constructed using the same construction methods as those used for the prefabricated integrated utility tunnel in the shield tunnel.

[0016] This invention has the following characteristics and beneficial effects: 1. This invention uses rebar installation to effectively connect the precast curved wall to the shield tunnel segments within the shield tunnel. The gap between the precast curved wall and the shield tunnel segments is reinforced with C40 self-compacting high-strength cement-based grout. High-strength mortar is injected at the tongue and groove joint between the precast curved wall and the cast-in-place base for sealing and anchoring. This effectively ensures the firmness of the connection between the precast curved wall and the shield tunnel segments and base, reduces the phenomenon of loosening and disconnection in the later stage, and improves the safety and service life of the integrated utility tunnel under normal use.

[0017] 2. This invention uses a positioning steel plate to precisely position and install the embedded reinforcement bars inside the cast-in-place base. A reserved sleeve with inlet and outlet grout pipes is set inside the precast partition wall. The reserved sleeve of the precast partition wall is aligned with the embedded reinforcement bars for installation, which improves the efficiency and positioning accuracy of the partition wall installation. Special mortar is injected into the reserved sleeve through the grout inlet pipe for anchoring. High-strength mortar is injected into the gap between the precast partition wall and the cast-in-place base, which enhances the overall integrity of the connection between the precast partition wall and the cast-in-place base.

[0018] 3. In this invention, the cast-in-place diaphragm is provided with edge ribs on both sides and a central rib in the middle. The reinforcing bars of the diaphragm are welded together with the reserved reinforcing bars of the precast base and the precast diaphragm wall, thus integrally casting the cast-in-place diaphragm with the edge ribs and the central rib. This improves the overall integrity of the connection between the cast-in-place diaphragm and the precast base and the precast diaphragm wall, and solves the problem of weak connection between the cast-in-place diaphragm and the supporting structure. 4. The present invention uses a disc-lock full-span support system for the cast-in-place diaphragm, and the central rib is supported by tie rods, which speeds up the formwork efficiency of the diaphragm and saves formwork space. Attached Figure Description

[0019] Figure 1 This is a diagram showing the internal structure of the prefabricated integrated utility tunnel for shield tunnels according to the present invention. Figure 2 This is a structural diagram of the pre-embedded reinforcement for fixing the positioning steel plate inside the cast-in-place base of the shield tunnel according to the present invention; Figure 3 This is a detailed drawing of the pre-embedded reinforcement structure for positioning and fixing the positioning steel plate of the present invention; Figure 4 This is a detailed drawing of the prefabricated curved wall structure of the present invention; Figure 5 This is a schematic diagram of the assembly of prefabricated modular components for shield tunnels according to the present invention; Figure 6 This is a detailed drawing of the prefabricated partition wall structure of the present invention; Figure 7 This is a structural diagram of the connection between the prefabricated partition wall and the cast-in-place base in the shield tunnel of the present invention; Figure 8 This is a diagram of the formwork structure for the cast-in-place central diaphragm of the prefabricated integrated utility tunnel in the shield tunnel of this invention. Figure 9 This is a detailed drawing of the support structure for the edge ribs of the cast-in-place central diaphragm in the shield tunnel of the present invention; Figure 10 This is a detailed drawing of the formwork structure for the central rib plate of the cast-in-place diaphragm in the shield tunnel of the present invention; Figure 11 This is a detailed drawing of the connection between the uprights and the U-shaped brackets of the disc-lock type full-span support system of the present invention; Figure 12 This is a structural diagram of the back of a prefabricated curved wall; Figure 13This is a longitudinal sectional view of a prefabricated curved wall.

[0020] The components are: 1-Shield tunnel segment; 2-Arc-shaped cushion layer; 3-Cast-in-place base; 4-Precast arc-shaped wall; 5-Arc-shaped wall joint; 6-Precast central partition wall; 7-Rebar installation; 8-Precast base; 9-Cast-in-place central partition plate; 10-Edge rib plate; 11-Central rib plate; 12-Base reinforcement; 13-Positioning steel plate; 14-Embedded reinforcement; 15-Pre-set reinforcement hole; 16-Grouting pipe; 17-Tie joint; 18-Reserved reinforcement for central partition wall; 19-Reserved sleeve; 20-Grouting inlet pipe; 21-Grouting outlet pipe; 22-Special mortar; 23-Mold sealing; 24-High-strength mortar; 25-Mortar-stopping pad; 26-Support pad; 27-Upright pole; 28-Horizontal bar; 29-U-shaped bracket; 30-Top horizontal main rib; 31-Secondary rib; 32-Formwork; 33-Tie rod; 34-L-shaped formwork; 35-Base reserved reinforcement; 36-Middle partition plate reinforcement; 37-First vertical main rib; 38-Second vertical main rib; 39-Positioning buffer airbag; 40-Base plate; 41-Exhaust port; 42-Receiving groove; 43-Guide column; 44-Guide hole. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention are within the scope of protection of the present invention.

[0022] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting this invention.

[0023] It is understood that the term "a" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element can be one, while in another embodiment, the number of the element can be multiple, and the term "a" should not be understood as a limitation on the number.

[0024] The basic structure of shield tunnels, the dimensions and prefabrication process of each precast component, key points of rebar installation technology, self-compacting high-strength cement-based grouting process, special mortar mix ratio and grouting technology, high-strength mortar pouring process, key points of precast partition wall installation, erection method of disc-lock full-span support system, materials and diameters of various steel bars, types and installation methods of related bolts, concrete pouring process, etc., will not be repeated here. The focus is on describing the implementation method of the structure involved in this invention.

[0025] like Figure 1 The diagram shown illustrates the internal structure of the prefabricated integrated utility tunnel in the shield tunnel. It mainly consists of shield tunnel segments 1, cast-in-place base 3, prefabricated curved walls 4, prefabricated central partition walls 6, prefabricated base 8, and cast-in-place central partitions 9.

[0026] like Figure 2-3 The diagram shows the structure of the pre-embedded reinforcement fixed to the positioning steel plate in the cast-in-place base of the shield tunnel. It includes the cast-in-place base 3, the base reinforcement 12, the positioning steel plate 13, and the pre-embedded reinforcement 14. The pre-embedded reinforcement 14 is preset in the cast-in-place base 3. The pre-embedded reinforcement 14 is positioned by the positioning steel plate 13. The positioning steel plate 13 has multiple pre-set reinforcement holes. The pre-embedded reinforcement 14 is inserted into the reinforcement holes of the positioning steel plate 13. The positioning steel plate 13 is welded to the base reinforcement 12.

[0027] like Figure 1 , 4 The detailed drawing of the precast curved wall structure shown includes a precast curved wall 4, pre-set rebar holes 15, and grouting pipes 16. The precast curved wall 4 is assembled from multiple precast curved wall segments. Each precast curved wall segment has multiple pre-set rebar holes 15, and grouting pipes 16 are installed on the precast curved wall segments. Rebars 7 are inserted into the pre-set rebar holes 15 of the precast curved wall segments and are inserted into the shield tunnel segments 1, thus connecting the precast curved wall 4 and the shield tunnel segments 1. C40 self-compacting high-strength cement-based grout is injected into the gap between the precast curved wall 4 and the shield tunnel segments 1, and the C40 self-compacting high-strength cement is injected through the grouting pipes 16. Masking tape is pasted on both sides of the curved wall joint 5 between two adjacent precast curved wall segments.

[0028] During the hoisting and placement of the precast curved wall segment, it may collide with the inner side of the tunnel segment 1. For example... Figure 12 , Figure 13As shown, to reduce the impact force generated on the inner side of the shield tunnel segment 1 during the hoisting and placement of the precast curved wall segment, and to reduce impact damage to the inner side of the shield tunnel segment 1, a placement buffer airbag 39 is installed on the back of the precast curved wall segment. A receiving groove 42 is provided at each of the four corners of the back of the precast curved wall segment, and the placement buffer airbag 39 is placed in the receiving groove 42. One end of the placement buffer airbag 39 is connected to the bottom of the receiving groove 42, and the other end of the placement buffer airbag 39 is provided with a base plate 40. The placement buffer airbag 39 is made of rubber, and several exhaust ports 41 are arranged on the side of the placement buffer airbag 39 near the base plate. The placement buffer airbag 39 has a corrugated tube structure. A guide post 43 is provided on the base plate 40, and a guide hole 44 corresponding to the guide post 43 is provided on the prefabricated curved wall segment; the guide post 43 and the guide hole are slidably engaged; the expansion and contraction direction of the positioning buffer airbag 39 is constrained by the engagement of the guide post 43 and the guide hole 44. When the two ends of the positioning buffer airbag 39 are compressed, the positioning buffer airbag 39 contracts axially, and the positioning buffer airbag 39 can be completely retracted into the storage groove in the contracted state.

[0029] like Figure 5 The schematic diagram of the prefabricated assembly of shield tunnel components shown includes shield tunnel segments 1, arc-shaped cushion layer 2, cast-in-place base 3, prefabricated arc-shaped wall 4, arc-shaped wall joint 5, tongue and groove joint 17, high-strength mortar 24, etc. An arc-shaped cushion layer 2 is cast between the cast-in-place base 3 and the shield tunnel segment 1. Tongue and groove joint 17 is provided between the lower part of both sides of the cast-in-place base 3 and the shield tunnel segment 1. The lower part of the prefabricated arc-shaped wall 4 is inserted into the tongue and groove joint 17. The connection between the prefabricated arc-shaped wall 4 and the cast-in-place base 3 is sealed by injecting high-strength mortar 24.

[0030] like Figure 6 The detailed drawing of the prefabricated partition wall structure shown includes a prefabricated partition wall 6, reserved sleeves 19, grout inlet pipes 20, grout outlet pipes 21, etc. Multiple reserved sleeves 19 are evenly spaced at the lower part of the prefabricated partition wall 6. The reserved sleeves 19 are evenly spaced in multiple rows along the longitudinal direction of the prefabricated partition wall 6, and each row includes two reserved sleeves 19. The grout inlet pipes 20 are provided at the bottom of the reserved sleeves 19, and the grout outlet pipes 21 are provided at the top of the reserved sleeves 19.

[0031] like Figure 7The diagram shown illustrates the connection structure between the precast intermediate partition wall and the cast-in-place base in a shield tunnel. It includes the cast-in-place base 3, the precast intermediate partition wall 6, embedded reinforcing bars 14, a reserved sleeve 19, a grout inlet pipe 20, a grout outlet pipe 21, special mortar 22, a sealing formwork 23, high-strength mortar 24, and a grout-stopping pad 25. The precast intermediate partition wall 6 is assembled from several precast intermediate partition wall segments. When assembling the precast intermediate partition wall 6 with the cast-in-place base 3, the embedded reinforcing bars 14 on the cast-in-place base 3 are inserted into the reserved sleeve 19 at the bottom of the precast intermediate partition wall 6. Special mortar 22 is poured into the reserved sleeve 19, which is then injected through the grout inlet pipe 20 and overflows from the grout outlet pipe 21. A grout-stopping pad 25 is provided between the reserved sleeve 19 and the cast-in-place base 3. High-strength mortar 24 is injected into the gap between adjacent grout-stopping pads 25. The high-strength mortar 24 is sealed by a sealing mold 23 to prevent grout overflow. The sealing mold 23 is set on the outer perimeter of the bottom of the precast intermediate partition wall 6 and surrounds the precast intermediate partition wall 6. High-strength mortar 24 is injected into the gap between the sealing mold 23 and the precast intermediate partition wall 6.

[0032] like Figure 8 , 11 The diagram shows the formwork structure for the cast-in-place central diaphragm of a prefabricated integrated utility tunnel in a shield tunnel. It includes a cast-in-place base 3, a prefabricated arc-shaped wall 4, a prefabricated central diaphragm wall 6, a prefabricated base 8, a cast-in-place central diaphragm 9, edge ribs 10, a central rib 11, a support pad 26, uprights 27, horizontal bars 28, a U-shaped support 29, a top transverse main rib 30, secondary ribs 31, and a template 32. The prefabricated arc-shaped wall 4 is assembled onto the prefabricated base 8. Edge ribs 10 are provided on both sides of the cast-in-place central diaphragm 9, located above the prefabricated base 8. A central rib 11 is located in the middle of the cast-in-place central diaphragm 9. A support pad 26 is provided on the cast-in-place base 3. Uprights 27 and horizontal bars 28 are erected on the support pad 26. A U-shaped support 29 is provided at the top of the uprights 27. The top transverse main rib 30 is placed inside the U-shaped support 29. Secondary ribs 31 and template 32 are sequentially provided on the top transverse main rib 30.

[0033] like Figure 9 The diagram shows a detailed view of the formwork structure for the edge ribs of the cast-in-place central diaphragm in a shield tunnel. It includes a precast base 8, edge ribs 10, horizontal bars 28, main ribs 30, secondary ribs 31, formwork 32, base reserved reinforcement 35, and central diaphragm reinforcement 36. The precast base 8 is equipped with base reserved reinforcement 35, which is integrally welded to the central diaphragm reinforcement 36. On the back of the formwork 32 on the side of the edge ribs 10, secondary ribs 31 and a first vertical main rib 37 are sequentially arranged. The first vertical main rib 37 on the back of the formwork 32 on the side of the edge ribs 10 is arranged vertically and is secured by horizontal bars 28 and top horizontal main ribs 30.

[0034] like Figure 10The diagram shows a detailed view of the formwork structure for the central rib of the cast-in-place central diaphragm in a shield tunnel. It includes a precast central diaphragm wall 6, a central rib 11, pre-reserved reinforcing bars 18, second vertical main ribs 38, secondary ribs 31, a formwork 32, tie rods 33, an L-shaped formwork 34, and central diaphragm reinforcing bars 36. Multiple pre-reserved reinforcing bars 18 are installed at the top of the precast central diaphragm wall 6, and these bars are integrally welded to the central diaphragm reinforcing bars 36. The central rib 11 is supported and cast using L-shaped formwork 34 on both sides. Secondary ribs 31 and second vertical main ribs 30 are sequentially installed on the back of the L-shaped formwork 34, and tie rods 33 are used to tighten and compress the second vertical main ribs 30 on both sides.

[0035] This invention also provides a construction method for the internal structure of a prefabricated integrated utility tunnel in a shield tunnel, comprising the following steps: Step 1: Construction Preparation According to the design dimensions, precast curved wall segments, precast central partition wall segments, and precast bases are processed and manufactured in the concrete component factory. The installation positions are measured and laid out on shield tunnel segment 1 according to the design. The precast components are transported to the construction site and the surface of the precast components is checked to see if they are dense, smooth, flat, and have intact edges and corners without damage.

[0036] Step 2: Roughening and rebar installation inside the tunnel lining segments: The contact surface between the shield tunnel segment 1 and the precast curved wall 4 is roughened to expose the aggregate surface. At least 96% of the slurry skin on the roughened concrete surface should be removed, and the area of ​​the roughened surface should not be less than 80% of the contact surface. Vertical holes are drilled in the shield tunnel segment 1 along the rebar anchoring location using an impact drill to obtain rebar anchoring holes. The diameter of the rebar anchoring hole is 4-10 mm larger than the diameter of the rebar 7, and the depth of the rebar anchoring hole is 10-15 times the diameter of the rebar 7. The dust on the hole wall is repeatedly cleaned using a brush and compressed air.

[0037] Step 3: Casting the base in place: According to the measurement and layout position, first pour an arc-shaped pad 2 on the bottom inner side of the shield segment 1, tie the base reinforcement 12 on the arc-shaped pad 2, and weld the positioning steel plate 13 on the base reinforcement 12 according to the design position. After the pre-embedded reinforcement 14 passes through the reinforcement hole reserved on the positioning steel plate 13, it is welded to the base reinforcement 12. Then, the formwork of the cast-in-place base 3 is erected, and the concrete of the cast-in-place base 3 is poured. The two sides of the cast-in-place base 3 form a tongue and groove 17 with the shield segment 1.

[0038] Step 4: Assemble the prefabricated curved wall: Inside the shield tunnel, a modified tire-mounted forklift is used to install prefabricated arc wall segments in sequence according to their numbers. The prefabricated arc wall segments are tightly attached to the inner wall of the shield segment 1. Masking tape is pasted on both sides of the arc wall joint 5 between adjacent prefabricated arc wall segments. The joint width of the arc wall joint 5 is uniformly set to 4cm, and an interface brush joint is used for treatment. The masking tape is removed after the joint has reached the required strength. The prefabricated arc wall segments are assembled to form a prefabricated arc wall 4. A prefabricated base 8 is installed on the top of the prefabricated arc wall 4. The prefabricated base 8 and the top of the prefabricated arc wall 4 are connected by a concave-convex interlocking structure. High-strength mortar 24 is poured into the gap at the connection between the two for anchoring.

[0039] Before hoisting the precast curved wall segment, the positioning buffer airbag 39 is stretched to its longest position, so that it is higher than the receiving groove 42. During the installation and positioning of the precast curved wall segment, the bottom plate of one end of the positioning buffer airbag 39 contacts the inner side of the shield segment 1, and the positioning buffer airbag 39 is compressed, causing the air inside the positioning buffer airbag 39 to be discharged outward through the exhaust port 41. In this process, the gradual contraction of the positioning buffer airbag 39 plays a buffering role in the positioning of the precast curved wall segment. This reduces the impact between the precast curved wall segment and the inner side of the shield segment 1; at the same time, the air inside the positioning buffer airbag 39 is discharged to the side of the positioning buffer airbag 39 through the exhaust port 41, and the airflow blown out through the exhaust port 41 can blow towards the inner surface of the shield segment 1, which can remove dust from the inner surface of the shield segment 1 and play a certain cleaning role; when grouting is subsequently carried out between the precast curved wall 4 and the shield segment 1, it can make the grouting material better bond with the inner surface of the shield segment 1.

[0040] Step 5: Install the sealing mold and grout stop gasket: After the concrete of the cast-in-place base 3 reaches the designed strength, a grout stop pad 25 is set on the top of the cast-in-place base 3. The pre-embedded reinforcement 14 on the cast-in-place base 3 passes through the grout stop pad 25. A sealing mold 23 is set around the area to be installed in the precast partition wall 6 on the top of the cast-in-place base 3.

[0041] Step Six: Assemble the prefabricated partition wall: The precast partition wall segments are lifted in sections according to their numbering sequence using a modified tire forklift. After the reserved sleeve 19 at the bottom of the lowest precast partition wall segment is aligned with the quasi-embedded reinforcement 14 on the cast-in-place base 3, the precast partition wall segment is slowly lowered so that the embedded reinforcement 14 is inserted into the reserved sleeve 19. The lower part of the reserved sleeve 19 is sealed by the grout stop pad 25. The precast partition wall segments are assembled sequentially from bottom to top to obtain the precast partition wall. Masking tape is applied to both sides of the joint between two adjacent precast partition wall segments. First, the joint between the precast partition wall segments is grouted to a depth of not less than 1cm. After the grooving reaches the required strength, the grouting material is prepared according to the design requirements and poured in two stages from top to bottom. After the first pour, a thin steel bar is inserted repeatedly to ensure that the bottom grouting material is vibrated and compacted. After there are no air bubbles on the surface of the grouting material, the grouting is poured again to the top of the precast partition wall 6.

[0042] Step 7: Rebar installation for precast curved walls: The anchoring adhesive is slowly injected into the pre-set rebar hole 15 of the precast curved wall 4, and the anchoring adhesive is filled to 2 / 3 of the depth of the anchoring hole on the shield segment 1. The anchoring bar 7 is inserted into the pre-set rebar hole 15 of the precast curved wall 4. The anchoring bar 7 is inserted to the bottom of the hole of the shield segment 1 while rotating, to ensure that the adhesive is evenly coated.

[0043] Step 8: Grouting behind the precast curved wall: After the precast curved wall 4 is assembled, a 30mm wide gap is formed between the precast curved wall 4 and the shield tunnel segment 1. C40 self-compacting high-strength cement-based grout is filled into this gap, and grouting is performed from bottom to top. Grouting pipes 16 are pre-installed on the precast curved wall segments, including a bottom grouting pipe and a middle grouting pipe. Grouting begins from the bottom grouting pipe 16 on the precast curved wall segment. After the grouting pipe 16 in the upper middle part of the wall segment overflows outward, the bottom grouting pipe 16 is sealed. Grouting continues from the grouting pipe 16 in the upper middle part of the precast curved wall segment until the grout overflows from the pre-set steel bar hole 15 in the upper part of the precast curved wall segment. Finally, the pre-set steel bar hole 15 is sealed, thus completing the grouting operation of this unit. Then, the grouting operation of the next unit is carried out. High-strength mortar 24 is injected into the tongue and groove joint 17 connecting the precast curved wall 4 and the cast-in-place base 3 for sealing.

[0044] Step 9: Grouting connection of the reserved sleeve: Special mortar 22 and high-strength mortar 24 are prepared according to the designed mix ratio. Special mortar 22 is injected into the pre-reserved sleeve 19 through the inlet pipe 20 at the bottom of the pre-reserved sleeve 19 using a grouting machine. When the grout overflows from the outlet pipe 21 at the top of the pre-reserved sleeve 19 and there are no air bubbles, the outlet pipe 21 is blocked. The grouting pressure is 0.2-0.3 N / mm². After all outlet pipes 21 are blocked, grouting and pressure holding are carried out for a time of not less than 1 minute. At the same time, high-strength mortar 24 is injected into the gap between adjacent grout stop pads 25 for sealing. High-strength mortar 24 is injected into the gap between the precast partition wall 6 and the sealing mold 23 for caulking.

[0045] Step 10: Erect the formwork support for the central partition: A disc-lock type full-span support system is adopted. A support plate 26 is laid on the top of the cast-in-place base 3. A vertical pole 27 and a horizontal pole 28 are erected above the support plate 26. A U-shaped bracket 29 is installed on the top of the vertical pole 27. A top horizontal main rib 30 is placed on the U-shaped bracket 29. A secondary rib 31 and a template 32 are installed in sequence on the top horizontal main rib 30. A secondary rib 31 and a first vertical main rib 37 are arranged in sequence on the back of the template 32 located on the side of the edge rib 10. The first vertical main rib 37 is tightened by the horizontal pole 28 and the top horizontal main rib 30. A secondary rib 31 and a second vertical main rib 38 are arranged in sequence on the back of the L-shaped template 34 located on both sides of the central rib 11. The second vertical main ribs 38 on both sides are tightened by tie rods 33.

[0046] Step 11: Tie the reinforcing bars of the central diaphragm: The top of the prefabricated partition wall 6 and the prefabricated base 8 that have been installed is roughened. The partition wall steel bars 36 are tied in the template 32. The partition wall steel bars 36 are then welded to the base reserved steel bars 35 reserved on the prefabricated base 8 and the partition wall reserved steel bars 18 reserved on the top of the prefabricated partition wall 6.

[0047] Step 12: Pour the concrete for the central diaphragm: The concrete for the cast-in-place central partition 9 is pumped and poured, with a slump controlled at 12-14cm, a water-cement ratio of <0.45, and a sand ratio of 40-45%. The precast base 8 and the edge ribs 10, as well as the precast central partition wall 6 and the central rib 11, are cast together to complete the construction of the internal structure of the precast assembled integrated utility tunnel in the shield tunnel.

[0048] This invention is not limited to the preferred embodiments described above. Anyone can derive other products in various forms under the guidance of this invention. However, regardless of any changes in shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A construction method for the internal structure of a prefabricated integrated utility tunnel in a shield tunnel, characterized in that, Includes the following steps: Step 1: Construction Preparation; Step 2: Roughening and rebar installation inside the tunnel lining segments; Step 3: Casting the base in place; According to the measurement and layout position, first pour an arc-shaped pad (2) on the bottom of the inner side of the shield segment (1), tie the base reinforcement (12) on the arc-shaped pad (2), weld the positioning steel plate (13) on the base reinforcement (12) according to the design position, and weld the pre-embedded reinforcement (14) through the reserved reinforcement hole on the positioning steel plate (13) to the base reinforcement (12); then set up the formwork of the cast-in-place base (3) and pour the concrete of the cast-in-place base (3); the two sides of the cast-in-place base (3) form a tongue and groove (17) with the shield segment (1). Step 4: Precast curved wall assembly: Install precast curved wall segments in sections to form a precast curved wall (4); install a precast base (8) on top of the precast curved wall (4); Step 5: Install the sealing mold and grout stop gasket; Step Six: Assemble the prefabricated partition wall; Step 7: Rebar installation for precast curved walls; Step 8: Grouting behind the precast curved wall; Step 9: Grouting connection of the reserved sleeve; Step 10: Erect the formwork support for the middle partition: Lay a support pad (26) on the top of the cast-in-place base (3), erect a vertical pole (27) and a horizontal pole (28) above the support pad (26), install a U-shaped bracket (29) on the top of the vertical pole (27), place the top horizontal main rib (30) on the U-shaped bracket (29), and install the secondary rib (31) and the formwork (32) on the top horizontal main rib (30) in sequence. Step 11: Tie the reinforcing bars of the central diaphragm: The top of the prefabricated partition wall (6) and the prefabricated base (8) is roughened. The partition wall steel bars (36) are tied in the template (32). The partition wall steel bars (36) are welded to the base reserved bars (35) reserved on the prefabricated base (8) and the partition wall reserved bars (18) at the top of the prefabricated partition wall (6). Step 12: Pour the concrete for the middle partition.

2. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, The specific method of step two is as follows: roughen the contact surface between the shield tunnel segment (1) and the precast arc wall (4), and use an impact drill to drill vertical holes on the shield tunnel segment (1) along the rebar location to obtain the rebar holes. The diameter of the rebar hole is 4-10mm larger than the diameter of the rebar (7), and the depth of the rebar hole is 10-15 times the diameter of the rebar (7). Use a brush and compressed air to repeatedly clean the dust on the hole wall.

3. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, In step four, the precast base (8) and the top of the precast curved wall (4) are connected by a concave-convex interlocking structure, and high-strength mortar (24) is poured into the gap at the connection between the two for anchoring.

4. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, A positioning buffer airbag (39) is provided on the back of the prefabricated curved wall segment; a storage groove (42) is provided at each of the four corners of the back of the prefabricated curved wall segment, and the positioning buffer airbag (39) is placed in the storage groove (42); one end of the positioning buffer airbag (39) is connected to the bottom of the storage groove (42), and the other end of the positioning buffer airbag (39) is provided with a base plate (40); several exhaust ports (41) are arranged on the side of the positioning buffer airbag (39) near the base plate; the positioning buffer airbag (39) has a corrugated pipe structure; a guide post (43) is provided on the base plate (40), and a guide hole (44) corresponding to the guide post (43) is provided on the prefabricated curved wall segment; the guide post (43) and the guide hole slide together; the extension and retraction direction of the positioning buffer airbag (39) is constrained by the cooperation of the guide post (43) and the guide hole (44); Before hoisting the precast curved wall segment, the placement buffer airbag (39) is stretched to its longest state, so that the placement buffer airbag (39) is higher than the receiving groove (42); during the installation and placement of the precast curved wall segment, the bottom plate of one end of the placement buffer airbag (39) contacts the inner side of the shield segment (1), and the placement buffer airbag (39) is compressed, causing the air inside the placement buffer airbag (39) to be discharged outward through the exhaust port (41); during this process, the gradual contraction of the placement buffer airbag (39) provides support for the precast curved wall segment. The placement serves as a buffer, reducing the impact between the precast curved wall segment and the inner side of the shield segment (1); at the same time, the air inside the placement buffer airbag (39) is discharged to the side of the placement buffer airbag (39) through the exhaust port (41), and the airflow blown out through the exhaust port (41) can blow towards the inner surface of the shield segment (1), which can remove the dust from the inner surface of the shield segment (1). When grouting is performed between the precast curved wall (4) and the shield segment (1) in the future, the grouting material can better bond with the inner surface of the shield segment (1).

5. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, The specific method of step five is as follows: After the concrete of the cast-in-place base (3) reaches the designed strength, a grout stop pad (25) is set on the top of the cast-in-place base (3), the pre-embedded reinforcement (14) on the cast-in-place base (3) passes through the grout stop pad (25), and a sealing mold (23) is set around the area to be installed in the precast partition wall (6) on the top of the cast-in-place base (3).

6. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, The specific method for step six is ​​as follows: the prefabricated partition wall segments are hoisted in sections. After the reserved sleeve (19) at the bottom of the lowest prefabricated partition wall segment is aligned with the quasi-embedded reinforcement (14) on the cast-in-place base (3), the prefabricated partition wall segment is slowly lowered so that the embedded reinforcement (14) is inserted into the reserved sleeve (19). The lower part of the reserved sleeve (19) is sealed by the grout stop pad (25). The prefabricated partition wall segments are assembled from bottom to top to obtain the prefabricated partition wall (6).

7. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, The specific method for step seven is as follows: slowly inject the anchoring adhesive into the pre-set rebar hole (15) of the precast curved wall (4), and fill the anchoring adhesive to 2 / 3 of the depth of the anchoring hole on the shield segment (1). Insert the anchoring bar (7) into the pre-set rebar hole (15) of the precast curved wall (4). Insert the anchoring bar (7) into the bottom of the hole of the shield segment (1) while rotating it to ensure that the adhesive is evenly coated.

8. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, The specific method for step eight is as follows: After the precast curved wall (4) is assembled, a 30mm wide gap is formed between the precast curved wall (4) and the shield tunnel segment (1). C40 self-compacting high-strength cement-based grout is filled into the gap. When filling the C40 self-compacting high-strength cement-based grout, grouting is carried out from bottom to top. There are grouting pipes (16) pre-installed on the precast curved wall segment. The grouting pipes (16) include the bottom grouting pipe and the middle grouting pipe. Grouting starts from the bottom grouting pipe (16) on the precast curved wall segment. When the precast curved wall segment is assembled, the grouting is carried out from bottom to top. After the grouting pipe (16) in the middle of the upper part of the arc wall segment overflows outward, the grouting pipe (16) at the bottom is sealed, and grouting continues from the grouting pipe (16) in the middle of the upper part of the precast arc wall segment until the grout overflows from the pre-set steel reinforcement hole (15) in the upper part of the precast arc wall segment. Finally, the pre-set steel reinforcement hole (15) is sealed, thus completing the grouting operation of this unit. Then, the grouting operation of the next unit is carried out. High-strength mortar (24) is injected into the tongue and groove joint (17) connecting the precast arc wall (4) and the cast-in-place base (3) to seal it. The specific method of step nine is as follows: Use a grouting machine to inject special mortar (22) from the grouting pipe (20) at the bottom of the reserved sleeve (19). When the grouting material overflows from the grouting pipe (21) at the top of the reserved sleeve (19) and there are no air bubbles, block the grouting pipe (21). The grouting pressure is 0.2-0.3 N / mm². After all the grouting pipes (21) are blocked, grouting and pressure holding are carried out. The pressure holding time is not less than 1 minute. At the same time, high-strength mortar (24) is injected into the gap between the adjacent grouting pads (25). High-strength mortar (24) is injected into the gap between the precast partition wall (6) and the sealing mold (23).

9. The construction method for the internal structure of the prefabricated integrated utility tunnel in a shield tunnel according to claim 1, characterized in that, In step ten, secondary ribs (31) and first vertical main ribs (37) are arranged sequentially on the back of the template (32) located on the side of the edge rib (10). The first vertical main rib (37) is tightened by the horizontal bar (28) and the top horizontal main rib (30). Secondary ribs (31) and second vertical main ribs (38) are arranged sequentially on the back of the L-shaped template (34) located on both sides of the central rib (11). The second vertical main ribs (38) on both sides are tightened by tie rods (33).

10. The internal structure of a prefabricated integrated utility tunnel in a shield tunnel, characterized in that: It is constructed using the construction method for the internal structure of the prefabricated integrated utility tunnel in shield tunnels as described in any one of claims 1-9.

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