A fully prefabricated assembled internal structure suitable for large-diameter shield tunnels and its construction method

Abstract

The present invention discloses a fully prefabricated internal structure suitable for a large-diameter shield tunnel and a construction method thereof, comprising: S1, after the shield machine excavates, the segments are assembled to form a closed circular tunnel; S2, the position of the U-shaped piece is determined, the U-shaped piece is hoisted, and multiple U-shaped pieces are longitudinally connected and assembled through shear keys; S3, the arc-shaped support plates on both sides of the U-shaped piece are hoisted, and the arc-shaped support plates are connected and assembled with the U-shaped piece through connecting bolts; S4, the three-span lane plate is hoisted, and the three-span lane plate is connected and assembled with the U-shaped piece and the arc-shaped support plate through connecting bolts; S5, multiple three-span lane plates are connected and assembled through longitudinal bolt hand holes; S6, all connecting bolts are tightened; S7, cement mortar filling material is used to fill the gaps, and grouting is performed through the grouting holes; S8, the cement mortar filling material is waited for to solidify, and the internal structure construction is completed. This method and internal structure greatly improve assembly efficiency and save manpower.

Description

Technical Field

[0001] The present invention relates to the technical field of an internal structure of a shield tunnel, and in particular to a fully prefabricated assembled internal structure suitable for a large-diameter shield tunnel and a construction method thereof. Background Art

[0002] Shield tunnels are currently the most widely used type of urban tunnel. Their mechanized construction makes them highly safe and efficient. The interior of a shield tunnel is designed according to its intended function, and various layouts can be used. While meeting functional requirements, the cross-sectional dimensions should be minimized to minimize investment.

[0003] For large-diameter shield tunnels, in order to make full use of the shield cross-section, the current layout of traffic tunnel lane slabs and their supporting structures mostly adopts a "π"-type structural system. In order to improve the overall assembly efficiency of the tunnel, a combination of prefabricated box culverts and cast-in-place / post-cast slabs or prefabricated side span lane slabs is usually adopted. The middle span is generally a prefabricated "mouth" type or "n" type box culvert, and cast-in-place slabs, post-cast composite slabs or prefabricated slab components are used on both sides to increase the proportion of prefabricated structures and meet the needs of tunnel construction progress. The above-mentioned box culverts are generally connected longitudinally and transversely with bolts, and the pre-embedded steel bar connection sleeves or bolts in the box culvert are connected to the side span lane slabs. The lane slabs on both sides generally also need to be provided with a cast-in-place base on the tunnel segments to meet the lane slab support needs.

[0004] According to current construction experience, the above technical solution still involves many internal structure construction steps and a large number of cast-in-place parts. The efficiency of tying steel bars in the tunnel is low, and there is more secondary damage to the pipe segments. The internal structure construction takes a long time.

[0005] The lane slab structure of the above technical solution is composed of two parts, the middle span and the side span, rather than a whole, and is prone to cracking and leakage at the joints and connections between the box culvert and the side span.

[0006] The joints between adjacent components of the internal structure of the above technical solution are all located on the same vertical plane, and the joints are concentrated, which weakens the overall performance of the internal structure. Moreover, due to the dynamic characteristics of the vehicle load, the stress concentration problem of the internal structure system with penetrating joints is more prominent, and fatigue cracking is prone to occur at the joints.

[0007] Overall, there's still room for improvement in the prefabrication ratio of internal structures, and the complexity of on-site construction necessitates further simplification of the construction process to improve efficiency. However, simply prefabricating the entire structure faces challenges with individual components: their large weight and size make them difficult to transport and hoist. Therefore, a rational prefabricated component combination system is key to improving internal structure prefabrication technology. Summary of the Invention

[0008] The purpose of the present invention is to overcome the above-mentioned technical deficiencies, provide a fully prefabricated and assembled internal structure suitable for large-diameter shield tunnels and its construction method, and solve the technical problems in the technical field of the internal structure of a shield tunnel in the prior art, such as the large number of construction steps of the tunnel internal structure, the large number of cast-in-place parts, and the low construction efficiency.

[0009] To achieve the above technical objectives, the technical solution of the present invention provides a fully prefabricated and assembled internal structure suitable for large-diameter shield tunnels and a construction method thereof, comprising the following steps:

[0010] S1. After the shield machine excavates, the segments are assembled to form a closed circular tunnel;

[0011] S2. Determine the position of the U-shaped member according to the centerline of the tunnel structure, hoist the U-shaped member, install shear keys in the shear key slots, and longitudinally connect and assemble multiple U-shaped members using the shear keys;

[0012] S3. Hoist the arc-shaped support plates on both sides of the U-shaped member, adjust the gap between the arc-shaped plate bosses and the pipe segments, align the embedded nuts at the lower ends of the arc-shaped support plates with the bolt holes of the U-shaped member, and temporarily install gaskets if necessary. Connect the arc-shaped support plates and the U-shaped member with the connecting bolts.

[0013] S4. Hoist the three-span lane plate and adjust its plane position so that the bolt holes of the three-span lane plate are aligned with the pre-embedded nuts of the U-shaped pieces and the curved support plates. At this point, the three-span lane plate is exactly across the top of the two adjacent U-shaped pieces. Connect the three-span lane plate, the U-shaped pieces, and the curved support plates with connecting bolts to assemble them into one piece.

[0014] S5. Connect and assemble multiple three-span lane slabs through longitudinal bolt holes to strengthen the integrity of the three-span lane slab structure;

[0015] S6. After completing the above steps, re-tighten all connecting bolts until they meet the design requirements;

[0016] S7. After the internal structure at one end is assembled, high-strength filling materials such as slightly expanded fine stone concrete or cement mortar are injected into the gap between the internal structure and the segments through the grouting holes of the U-shaped piece and the curved support plate to fill the gap and increase the effective contact area between the internal structure and the segments.

[0017] S8. Wait for the micro-expanding fine stone concrete or cement mortar filling material to solidify and the internal structure construction is completed.

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

[0019] 1. Compared with the existing technology, the prefabricated assembly system adopted in this patent can greatly improve the prefabrication assembly rate of the internal structure of the shield tunnel. All prefabricated components are connected by quick connection of bolts and shear keys, which can significantly speed up the construction progress and improve the construction quality.

[0020] 2. Compared with the existing technology, the lane plate component of this patent is a continuous beam in the transverse direction, which has better overall mechanical properties and is mainly fixed with bolts. The overall structural strength is high and it can be easily disassembled and replaced when encountering local damage.

[0021] 3. Compared with existing technologies, the joints between adjacent components of this patented internal structural system are staggered in plane, resulting in evenly distributed joints and improved structural integrity. Furthermore, the staggered joint system of the present invention ensures that the joints between the lane slab, box culvert, and pipe segments are staggered, significantly reducing stress reflection at the joints caused by vehicle loads in the prefabricated structural system, effectively reducing the risk of cracking at the joints of the road layer and fill layer.

[0022] 4. The prefabricated assembly system adopted in this patent can be quickly installed and formed. The prefabricated assembly system can adapt to the synchronous construction of the shield machine, and can also be constructed separately from the shield machine. It can be selected according to the actual process arrangement to reduce process interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic cross-sectional view of a fully prefabricated and assembled internal structure suitable for a large-diameter shield tunnel provided by the present invention;

[0024] Figure 2 It is a ground and elevation diagram of the three-span lane slab provided by the present invention;

[0025] Figure 3 Schematic diagram of the top and elevation of the U-shaped member provided by the present invention;

[0026] Figure 4 Schematic diagram of the top surface and elevation of the arc-shaped support plate provided by the present invention;

[0027] Figure 5 It is a planar schematic diagram of the internal structure assembly provided by the present invention;

[0028] Figure 6 This is a schematic diagram of the installation of the shear key and shear key slot provided by the present invention.

[0029] In the accompanying drawings, the list of components represented by each number is as follows: 1. Three-span lane slab; 2. U-shaped part; 3. Arc-shaped support plate; 4. Connecting bolt; 5. Shear key; 6. Intermediate support node; 7. Shear key slot; 8. Side span support node; 9. Bolt hole; 10. Side wall joint; 11. Grouting hole; 12. Embedded nut; 13. Safety escape hatch; 14. Arc-shaped plate boss; 15. Pipe segment; 16. Longitudinal bolt hand hole. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0031] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly attached to the other element or there may be an intermediate element. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only implementation methods.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] See also Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 This embodiment provides a fully prefabricated and assembled internal structure suitable for a large-diameter shield tunnel and a construction method thereof, including: a three-span lane 1 plate, a U-shaped member 2, a curved support plate 3, connecting bolts 4, a shear key 5, an intermediate support node 6, a shear key slot 7, a side span support node 8, a bolt hole 9, a side wall joint 10, a grouting hole 11, an embedded nut 12, a safety escape hatch 13, a curved plate boss 14, a pipe segment 15, and a longitudinal bolt hand hole 16.

[0034] S1. After the shield machine excavates underground, the segments 15 are assembled so that the segments 15 form a circular tunnel underground.

[0035] S2. After the circular tunnel is completed, the position of the U-shaped member 2 is determined according to the center line of the tunnel structure, and the U-shaped member 2 is hoisted by machinery. Side wall joints 10 are provided at the top ends of both sides of the U-shaped member 2. The overall shape of the side wall joints 10 is large in the middle and small at both ends, and the whole is dumbbell-shaped. A plurality of embedded nuts 12 are provided on the top of the side wall joints 10 for fixed connection with the three-span lane 1. The U-shaped member 2 is provided with a plurality of shear key grooves 7, which are respectively distributed on both sides of the bottom of the U-shaped member 2 and in the middle area of ​​the bottom. Secondly, the shear key grooves 7 are also distributed at the top ends of the side wall joints 10. The hoisted U-shaped member 2 is distributed longitudinally, and the shear keys 5 are placed in the shear key grooves 7 corresponding to the adjacent U-shaped members 2 to make the adjacent U-shaped members 2 fixedly connected.

[0036] S3. After the adjacent U-shaped members 2 are assembled and connected, the arc-shaped support plates 3 are mechanically hoisted. Each U-shaped member 2 is equipped with two arc-shaped support plates 3. The two arc-shaped support plates 3 are evenly and symmetrically assembled and connected on both sides of the U-shaped member 2. The inner diameter of the arc-shaped support plate 3 matches the inner diameter of the pipe segment 15. The top and bottom ends of the arc-shaped support plate 3 are pre-embedded with a plurality of pre-embedded nuts 12. The bottom end of the arc-shaped support plate 3 and the bottom end of the U-shaped member 2 are fixedly connected by inserting the pre-embedded nuts 12 through the connecting bolts 4. The arc-shaped support plate 3 has a plurality of arc-shaped plate bosses 14 on one side close to the pipe segment 15. One end face of the arc-shaped plate boss 14 is tightly fitted with the pipe segment 15. The arrangement of the arc-shaped plate boss 14 is conducive to the positioning and installation of the arc-shaped support plate 3. A safety escape hatch 13 can be opened on one side of the two sides of the U-shaped member 2. The safety escape hatch 13 is convenient for personnel maintenance and evacuation and rescue.

[0037] S4. When the two sides of the U-shaped member 2 are fixedly connected to the arc-shaped support plate 3, the three-span lane plate 1 is lifted mechanically, and the plane position of the three-span lane plate 1 is adjusted at the same time so that the bolt holes 9 of the three-span lane plate 1 are aligned with the pre-embedded nuts 12 of the U-shaped member 2 and the arc-shaped support plate 3. The three-span lane plate 1 is provided with two side span support nodes 8 and two middle support nodes 6. The two side span support nodes 8 are located on both sides of the three-span lane plate 1, and the two middle support nodes 6 are evenly distributed in the middle area of ​​the three-span lane plate 1. The middle support node 6 is provided with a groove, and the shape of the groove is small at both ends. The middle is larger, and the shape of the groove matches the shape of the side wall joint 10. The side wall joint 10 is clamped in the groove of the middle support node 6. The middle support node 6 and the side span support node 8 are both reserved with a number of bolt holes 9. The middle support node 6 of the three-span lane slab 1 is connected to the embedded nut 12 in the side wall joint 10 in the U-shaped part 2 through the connecting bolt 4 to form a whole. The side span support point 8 of the three-span lane slab 1 is connected to the embedded nut 12 in the arc support plate 3 through the connecting bolt 4 to form a whole. At this time, the three-span lane slab 1, the arc support plate 3 and the U-shaped part 2 are assembled and connected as a whole.

[0038] S5. After completing step S4, repeat S1, S2, and S3 to assemble and connect the U-shaped parts 2 and the arc-shaped support plates 3 in an array. Then continue to hoist the three-span lane slabs 1 for adjacent assembly. A plurality of longitudinal bolt hand holes 16 are provided on one side in the longitudinal direction of the three-span lane slab 1, and corresponding embedded nuts 12 are provided on the other side in the longitudinal direction of the three-span lane slab 1. The longitudinal bolt hand holes 16 of the adjacent three-span lane slabs 1 correspond one to one to the embedded nuts 12, and the adjacent three-span lane slabs 1 are assembled and connected by the connecting bolts 4.

[0039] S6. After completing the above steps, in order to ensure the stability of the overall structure, the connecting bolts 4 are re-tightened and checked for looseness until they meet the engineering requirements.

[0040] S7. After completing the above steps, a plurality of grouting holes 11 are opened on the upper surface of the arc-shaped support plate 3, and a plurality of grouting holes 11 are also opened on the bottom end of the U-shaped member 2. During installation, the U-shaped member 2 and the arc-shaped support plate 3 form a certain gap with the pipe segment 15. High-strength filling materials such as micro-expanded fine stone concrete or cement mortar are used to inject grout into the grouting holes 11 of the U-shaped member 2 and the arc-shaped support plate 3 to fill the gap and increase the effective area between the internal structure and the pipe segment 15.

[0041] S8. Wait for the micro-expanding fine stone concrete or cement mortar filling material to solidify and the internal structure construction to be completed.

[0042] In this embodiment, the longitudinal lengths of the prefabricated components, including the three-span track slab 1, U-shaped member 2, and curved support plate 3, should match the segment width module, embodying the principle of modular design for prefabricated structures. While each prefabricated component can have different longitudinal lengths, the lengths of all components must meet the modular matching requirements for overall assembly. Furthermore, the component weights must meet the lifting capacity of the assembly equipment and be compatible with the shield tunnel dimensions, minimizing the number of joints.

[0043] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A construction method for a fully prefabricated internal structure of a large-diameter shield tunnel, characterized in that: The steps include: S1. After the shield machine excavates, the segments are assembled to form a closed circular tunnel; S2. Determine the position of the U-shaped member according to the centerline of the tunnel structure, hoist the U-shaped member, install shear keys in the shear key slots, and longitudinally connect and assemble multiple U-shaped members using the shear keys; S3. Hoist the arc-shaped support plates on both sides of the U-shaped member, adjust the gap between the arc-shaped plate bosses and the pipe segments, align the embedded nuts at the lower ends of the arc-shaped support plates with the bolt holes of the U-shaped member, temporarily install gaskets, and connect the arc-shaped support plates to the U-shaped member with the connecting bolts. S4. Hoist the three-span lane plate and adjust its plane position so that the bolt holes of the three-span lane plate are aligned with the pre-embedded nuts of the U-shaped pieces and the curved support plates. At this point, the three-span lane plate is exactly across the top of the two adjacent U-shaped pieces. Connect the three-span lane plate, the U-shaped pieces, and the curved support plates with connecting bolts to assemble them into one piece. S5. Connect and assemble multiple three-span lane slabs through longitudinal bolt holes to strengthen the integrity of the three-span lane slab structure; S6. After completing the above steps, re-tighten all connecting bolts until they meet the design requirements; S7. After the internal structure at one end is assembled, slightly expanded fine stone concrete or cement mortar is injected into the gap between the internal structure and the segments through the grouting holes of the U-shaped piece and the curved support plate to fill the gap and increase the effective contact area between the internal structure and the segments. S8. Wait for the micro-expanding fine stone concrete or cement mortar filling material to solidify and the internal structure construction to be completed; The three-span lane slab is provided with two intermediate support nodes and two side span support nodes; grooves are provided on the two intermediate support nodes; bolt holes are provided on the intermediate support nodes and the side span support nodes; the three-span lane slab is fixedly connected to the U-shaped part and the arc-shaped support plate by installing bolts through the bolt holes; the two side span support nodes are fixedly connected to the upper end of the arc-shaped support plate; side wall joints are provided on the top ends of both sides of the U-shaped part; the side wall joints are fixedly connected to the grooves; the inner diameter of the arc-shaped support plate matches the inner diameter of the pipe segment; a number of arc-shaped plate bosses are provided in the outer circle of the arc-shaped support plate.

2. The construction method of a fully prefabricated internal structure suitable for a large-diameter shield tunnel according to claim 1, characterized in that: The three-span lane slab is provided with longitudinal bolt hand holes; nuts are pre-embedded in the longitudinal bolt hand holes; adjacent three-span lane slabs are fixedly assembled and connected by installing bolts with the nuts.

3. The construction method of a fully prefabricated internal structure suitable for a large-diameter shield tunnel according to claim 1, characterized in that: The U-shaped parts are provided with shear key grooves; the shear key grooves of adjacent U-shaped parts correspond to each other one by one; and the adjacent U-shaped parts are fixedly assembled and connected by the shear keys built into the shear key grooves.

4. The construction method of a fully prefabricated internal structure suitable for a large-diameter shield tunnel according to claim 1, characterized in that: The U-shaped member and the arc-shaped support plate are provided with a plurality of grouting holes; the U-shaped member and the arc-shaped support plate are fixedly connected to the pipe segment by injecting slurry into the grouting holes and the force transmission area between the U-shaped member, the arc-shaped support plate and the pipe segment is increased.

5. The construction method of a fully prefabricated internal structure suitable for a large-diameter shield tunnel according to claim 1, characterized in that: A safety escape hatch is provided on one side of the U-shaped member, and the safety escape hatch is convenient for personnel inspection and evacuation.

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