Multifunctional prefabricated box culvert system in medium-diameter water delivery shield tunnel and construction method of multifunctional prefabricated box culvert system

Abstract

The invention provides a multifunctional prefabricated box culvert system in a medium-diameter water delivery shield tunnel and a construction method of the multifunctional prefabricated box culvert system. The prefabricated box culvert system comprises a box culvert body, a shield segment and a tunnel bottom backfill layer. A hollow area is arranged on a bottom plate of the box culvert body, an arc-shaped support formed by an arc-shaped protrusion is arranged at the bottom of the box culvert body, and the arc-shaped support is matched with the inner arc face of a shield segment to achieve radial leveling. An upper concave drainage channel is arranged at the lowermost end of the middle of the bottom plate; the top plate is provided with longitudinal connecting bolt holes and embedded positioning pin holes, the longitudinal connecting bolt holes are used for connecting adjacent sections, and the positioning pin holes are matched with the hoisting suction cups; and pre-embedded grouting holes are formed in the bottom plate and used for grouting gaps between the box culvert body and the shield segments to form a tunnel bottom backfill layer. Leveling bolts are replaced with the arc-shaped supports, the bottom plate hollowed-out area is arranged, the dead weight of the box culvert is reduced, the hoisting difficulty is lowered, the box culvert is designed to be provided with the longitudinal drainage channel, the construction difficulty is greatly lowered, the drainage problem in the box culvert in the operation period is solved, and the prefabricated box culvert system complete in function is formed.

Description

Technical Field

[0001] This invention relates to the field of shield tunnel construction, and in particular to a multifunctional prefabricated box culvert system and its construction method for a medium-diameter water conveyance shield tunnel. Background Technology

[0002] With the rapid development of my country's infrastructure, the shield tunneling method has been widely used in municipal highway tunnels, subway tunnels, and large-scale power systems, and the technology is relatively mature. Furthermore, with continuous technological advancements, the shield tunneling method has also been extended to urban water pipeline projects. Shield tunnels need to consider requirements such as pipeline installation space, operational monitoring equipment, and personnel maintenance space. Generally, medium-diameter shield tunnels are used, with secondary box culvert structures inside the tunnel serving as the foundation for the water pipeline and also as a passageway for construction and subsequent operation and maintenance. This facilitates the transportation of construction materials and operational maintenance. Considering the convenience of box culvert construction and the construction period, using an integral prefabricated structure for the box culvert inside the shield tunnel is more convenient. Existing multi-functional precast box culverts are connected longitudinally with bolts, and the bottom plate is equipped with leveling bolts. In order to reduce the lifting weight, a hollow area is often required in the bottom plate. Considering the drainage of the cable trench during the operation of the box culvert, the hollow area is backfilled with plain concrete after the lifting is completed. However, there are two major problems with the construction of multi-functional precast box culverts. First, after the box culvert is lifted, a second plain concrete backfilling and pouring is required. The internal working space of the box culvert is small, the second pouring is difficult, and it increases the cost and affects the tunneling construction period. Second, the leveling bolts in the bottom plate of the box culvert need to be pre-embedded during the precast box culvert construction. The box culvert needs to be leveled continuously during construction, which is a large amount of leveling work and greatly increases the workload and difficulty of construction. Summary of the Invention

[0003] In view of this, the purpose of this invention is to provide a multifunctional prefabricated box culvert system and its construction method for medium-diameter water conveyance shield tunnels. By using arc-shaped supports to replace leveling bolts, setting a hollow area in the bottom plate to reduce the self-weight of the box culvert, and designing a longitudinal drainage channel with a pre-embedded trapezoidal steel channel, the construction difficulty is greatly reduced, the workload is reduced to speed up the construction progress, and the self-weight of the box culvert is reduced to reduce the difficulty of hoisting and save costs.

[0004] The technical solution adopted by this invention to solve its technical problem is:

[0005] A multifunctional prefabricated box culvert system for medium-diameter water conveyance shield tunnels is provided, comprising: a box culvert body, shield segments, and a tunnel bottom backfill layer;

[0006] The box culvert body adopts a symmetrical design, with a hollow area on its bottom plate. The top plate of the box culvert body has longitudinal connecting bolt holes and pre-embedded positioning pin holes. The longitudinal connecting bolt holes are used to connect adjacent box culvert sections, and the pre-embedded positioning pin holes are adapted to hoisting suction cups. The bottom of the bottom plate is provided with an arc-shaped support formed by an arc-shaped protrusion structure. The outer arc surface of the arc-shaped support is adapted to the inner arc surface of the shield segment to achieve radial leveling. The bottom plate is provided with pre-embedded grouting holes for grouting into the gap between the box culvert body and the shield segment to form a tunnel bottom backfill layer. The lower surface of the bottom plate is provided with an integrally formed concave drainage channel along the longitudinal direction. The drainage channel can drain water accumulated in the tunnel during operation.

[0007] Preferably, the wedge shape of the box culvert body is adapted to the wedge shape of the shield tunnel segment, and the whole body is completely symmetrically designed, and the width matches the ring width of the shield tunnel segment; by matching the wedge shape and symmetrical design to adapt to the straight sections of the tunnel and the curved sections with different curve radii, and with the matching of the width and ring width, synchronous assembly with the shield tunnel segment and alignment of the circumferential joints can be achieved.

[0008] Preferably, the drainage channel is a drainage groove formed by a longitudinal concave top of the base plate. The cross-section of the drainage groove is an isosceles trapezoid, and a grout-stopping strip is continuously attached along the edge of the drainage groove to prevent grouting material from entering the drainage groove, ensuring smooth drainage after construction.

[0009] Preferably, a trapezoidal steel channel is pre-embedded on the inner side of the drainage channel, which fits against the side wall of the drainage channel. The upper edge of the trapezoidal steel channel is flush with the lower surface of the bottom plate, and the lower edge extends into the drainage channel. The inclined side of the pre-embedded trapezoidal steel channel is consistent with the inclination angle of the side wall of the drainage channel, and is fixedly connected to the bottom plate concrete by pre-embedded steel bars.

[0010] Preferably, the box culvert body adopts a symmetrical design, including cable segments and pipe segments symmetrically arranged on both sides of the cable segments. The cable segments and pipe segments are prefabricated as a whole, and their top and bottom plates are continuously connected. The cable segments are provided with longitudinally connected cable trenches, and the pipe segments are provided with longitudinally connected pipes.

[0011] Preferably, the arc-shaped support is arranged along the length of the base plate and is correspondingly arranged below the base plate of the cable trench. The radius of curvature of the outer arc surface of the arc-shaped support is adapted to the radius of curvature of the inner arc surface of the shield tunnel segment, so that the arc-shaped support can fit against the inner surface of the shield tunnel segment.

[0012] Preferably, the arc-shaped support is an arc-shaped protrusion structure integrally formed with the bottom plate, and its height is consistent with the design thickness of the tunnel bottom backfill layer; the number of the bottom plate hollow areas is three, which are respectively set on the bottom plates of the cable trench inside the box culvert body and the pipes on both sides, and the edges of the hollow areas are continuously fitted with grout-stopping strips.

[0013] Preferably, the diameter and depth of the pre-embedded positioning pin hole are adapted to the positioning pin of the lifting suction cup; during lifting, the positioning pin is inserted into the pin hole to realize the rapid alignment of the box culvert, and the suction cup is used to complete the lifting and placement.

[0014] Preferably, the longitudinal connecting bolt holes include upper bolt hand holes on the upper surface of the top plate and lower bolt hand holes on the lower surface, and the upper bolt hand holes and lower bolt hand holes are connected by an inclined channel; and the axis of the inclined channel is consistent with the longitudinal inclined bolt installation axis, forming an operating space for the longitudinal connecting bolts to pass through.

[0015] A construction method for a multifunctional precast box culvert system in a medium-diameter water conveyance shield tunnel is also provided, including the following steps:

[0016] S1. The factory uses high-precision molds to prefabricate the box culvert body described in any of the above items, simultaneously forming the concave drainage channel, the hollow area of ​​the bottom plate and the arc support, pre-embedding longitudinal connecting bolt holes, positioning pin holes and grouting holes, simultaneously pre-embedding trapezoidal steel channels and matching pre-embedded reinforcing bars, and pre-installing grout-stopping strips at the edge of the drainage channel.

[0017] S2. During shield tunnel excavation, the positioning pin of the hoisting suction cup is inserted into the pre-embedded positioning pin hole of the box culvert, and the box culvert is hoisted into position by adsorbing it. The initial radial leveling is completed by adapting the arc-shaped support to the shield segment.

[0018] S3. After the shield tunnel segments are installed, the box culvert is assembled simultaneously to align the circumferential joint of the box culvert with the circumferential joint of the tunnel segments. The adjacent segments are then secured by longitudinal diagonal bolts inserted through the bolt handholes.

[0019] S4. Grouting is injected into the gap between the box culvert and the segments through the pre-embedded grouting holes. The grout-stopping strip prevents the grout from entering the drainage channel and the hollow area. The grouting holes are sealed after grouting.

[0020] S5. Seal the bolt manholes with cement grout and fill the circumferential joints of the box culvert with waterproof mortar.

[0021] Repeat steps S2 through S5 to complete the installation of all box culverts.

[0022] The beneficial effects of this invention are:

[0023] This invention provides a multifunctional prefabricated box culvert system and its construction method for medium-diameter water conveyance shield tunnels. The system utilizes an arc-shaped protrusion structure on the bottom plate to form an arc-shaped support, replacing traditional leveling bolts. This eliminates the bolt leveling process, significantly reducing the difficulty of box culvert construction, minimizing leveling workload, and accelerating construction progress. The hollowed-out area on the bottom plate effectively reduces the box culvert's self-weight and lowers hoisting difficulty. The elimination of the secondary plain concrete backfilling process in the hollowed-out area reduces construction operations in the confined space inside the box culvert. A drainage channel is longitudinally arranged at the lower end of the bottom plate, employing a longitudinally concave isosceles trapezoidal hole structure with pre-embedded trapezoidal steel channels that fit against the sidewalls. This enhances the structural stability of the drainage channel and effectively solves drainage blockage problems during cable trench operation, improving the reliability of box culvert operation. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the cross-sectional structure of a multifunctional prefabricated box culvert system in a medium-diameter water conveyance shield tunnel according to Embodiment 1 of the present invention.

[0025] Figure 2 This is a schematic diagram of the overall structure of a multifunctional prefabricated box culvert system in a medium-diameter water conveyance shield tunnel according to Embodiment 1 of the present invention.

[0026] Figure 3 This is a schematic plan view of the bottom plate of the box culvert body according to Embodiment 1 of the present invention.

[0027] Figure 4 This is a schematic plan view of the top plate of the box culvert body according to Embodiment 1 of the present invention.

[0028] Figure 5 For the present invention Figure 4 A schematic diagram of the cross-section of the box culvert AA.

[0029] Figure 6 For the present invention Figure 4 A schematic diagram of the cross-section of the box culvert BB.

[0030] Figure 7 This is a reference sectional view showing the usage state of the longitudinal connecting bolt holes in Embodiment 1 of the present invention.

[0031] Figure 8 This is a physical state diagram of the present invention.

[0032] In the diagram: 1. Box culvert body; 2. Shield tunnel segment; 3. Longitudinal connecting bolt hole; 4. Positioning pin hole; 5. Hollow area; 6. Grouting hole; 7. Tunnel bottom backfill layer; 8. Drainage channel; 9. Trapezoidal steel channel; 10. Arc-shaped support; 11. Lower bolt hand hole; 12. Upper bolt hand hole.

[0033] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0034] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] like Figures 1-8 As shown, a multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel includes: a box culvert body 1, shield tunnel segments 2, and a tunnel bottom backfill layer 7.

[0037] The bottom plate of the box culvert body 1 has a hollow area 5, and the top plate of the box culvert body 1 has longitudinal connecting bolt holes 3 and pre-embedded positioning pin holes 4. The longitudinal connecting bolt holes 3 are used to connect adjacent box culvert sections, and the pre-embedded positioning pin holes 4 are adapted to the lifting suction cup. The bottom of the bottom plate is provided with an arc-shaped support 10 formed by an arc-shaped protrusion structure. The outer arc surface of the arc support 10 is adapted to the inner arc surface of the shield segment 2 to achieve radial leveling. The bottom plate is provided with pre-embedded grouting holes 6, which are used to inject grout into the gap between the box culvert body 1 and the shield segment 2 to form a tunnel bottom backfill layer 7. The lower surface of the bottom plate is provided with an integrally formed concave drainage channel along the longitudinal direction. The drainage channel can drain water accumulated in the tunnel during operation.

[0038] It should be noted that the box culvert body 1, as the main load-bearing and functional carrier, has been optimized in all structural designs to address the pain points of traditional box culvert construction. In terms of the bottom plate design, on the one hand, there is a hollow area 5, which effectively reduces the self-weight of the box culvert by reducing the amount of concrete used, thereby reducing the difficulty of hoisting in the tunnel and simplifying the construction process. On the other hand, the bottom of the bottom plate is provided with an arc-shaped support 10 formed by an arc-shaped protrusion structure. The outer arc surface of this support is precisely matched with the inner arc surface of the shield segment 2, which can replace the traditional leveling bolts to achieve radial self-leveling of the box culvert body 1, reducing the workload and complexity of leveling operations. The lower surface of the bottom plate is also provided with an integrated concave drainage channel along the longitudinal direction, which can be directly used as a drainage path for water accumulation during tunnel operation without the need for secondary construction, solving the problem of water accumulation in the cable trench and inside the box culvert, and ensuring structural safety and operational reliability. The top slab design includes longitudinal inclined bolts, matching longitudinal connecting bolt holes 3, and pre-embedded positioning pin holes 4. The longitudinal inclined bolts are used to firmly connect adjacent box culvert segments into a whole. The matching hand holes provide operating space for the bolts to be inserted and tightened, avoiding excessive weakening of the top slab structure strength. The pre-embedded positioning pin holes 4 are adapted to the positioning structure of the hoisting suction cup, ensuring that the box culvert can be quickly and accurately aligned when hoisted into place. In addition, the bottom slab is also provided with pre-embedded grouting holes 6. During construction, grouting material is injected into the gap between the box culvert body 1 and the shield segment 2 through these holes. After curing, it forms the tunnel bottom backfill layer 7, making the box culvert and the shield segment 2 form a tightly fitted whole force system, further improving the structural stability. The overall design not only meets the functional requirements of medium-diameter water conveyance shield tunnels, but also significantly reduces construction difficulty and improves construction efficiency.

[0039] The wedge shape of the box culvert body 1 is adapted to the wedge shape of the shield tunnel segment 2, and the whole body is completely symmetrical. The width is matched with the ring width of the shield tunnel segment 2. By matching the wedge shape and symmetrical design, it is adapted to the straight section of the tunnel and the curved section with different curve radii. With the matching of the width and the ring width, it can achieve synchronous assembly with the shield tunnel segment 2 and alignment of the circumferential joints.

[0040] It should be noted that the wedge shape of the box culvert body 1 is perfectly matched with the wedge shape of the shield tunnel segment 2, and the overall design is completely symmetrical. This symmetry covers the layout of the internal cable trench and pipelines, as well as the setting of the external arc-shaped support 10 and the concave drainage channel. This allows the box culvert to adapt to the straight sections and curved sections with different curve radii of the shield tunnel without additional structural adjustments, solving the problem that traditional box culverts are difficult to adapt to curved lines. Furthermore, the width of the box culvert body 1 is precisely matched with the circumferential width of the shield tunnel segment 2. Combined with the wedge shape matching and symmetrical design, it can not only achieve synchronous assembly of the box culvert and the shield tunnel segment 2, but also ensure that the circumferential assembly joint of the box culvert is precisely aligned with the circumferential joint of the shield tunnel segment 2, avoiding assembly misalignment caused by dimensional deviations. This further ensures the integrity of the internal structure of the tunnel, reduces construction adjustment procedures, and meets the high-efficiency requirements of shield construction.

[0041] like Figure 6As shown, the drainage channel is a drainage groove 8 formed by a longitudinal concave bottom plate. The cross-section of the drainage groove 8 is an isosceles trapezoid, and a grout-stopping strip is continuously attached along the edge of the drainage groove 8 to prevent grouting material from entering the drainage groove 8.

[0042] It should be noted that the drainage channel is a drainage trough 8 formed by the longitudinal concavity of the bottom plate. The drainage space is directly reserved by the one-piece molding process, which eliminates the need for additional excavation or pouring of drainage structures after the box culvert is assembled. This adapts to the operation restrictions of the narrow construction space of the shield tunnel and avoids the problems of complicated procedures and large space occupation in the construction of traditional drainage structures. In addition, the cross-section of the drainage trough 8 is an isosceles trapezoid. This shape design can optimize the water flow guidance path, reduce the flow resistance of water in the channel, and improve the drainage smoothness. The continuous grout-stopping strips attached to the edge of the drainage trough 8 can effectively prevent the grouting material from entering the interior of the drainage trough 8 when grouting is injected into the gap between the box culvert and the shield segment 2 through the pre-embedded grouting holes 6 to form the tunnel bottom backfill layer 7. This prevents the channel from being blocked and ensures that the drainage trough 8 can be put into operation directly without additional cleaning after it is formed, ensuring the stable function of water drainage during tunnel operation.

[0043] like Figure 6 As shown, a trapezoidal steel channel 9 is pre-embedded on the inner side of the drainage channel 8, which fits against the side wall of the drainage channel 8. The upper edge of the trapezoidal steel channel 9 is flush with the lower surface of the bottom plate, and the lower edge extends into the drainage channel. The inclined side of the pre-embedded trapezoidal steel channel 9 is consistent with the inclination angle of the side wall of the drainage channel, and is fixedly connected to the bottom plate concrete by pre-embedded steel bars.

[0044] It should be noted that the trapezoidal steel channel 9 is pre-embedded inside the drainage channel 8 and fits tightly against the channel wall, ensuring that the steel channel and the drainage channel 8 form a unified structure, avoiding water leakage or local structural weakness due to gaps between them; the upper edge of the trapezoidal steel channel 9 is flush with the lower surface of the bottom plate, which can ensure the overall flatness of the box culvert bottom, and does not affect the bonding effect between the box culvert and the shield tunnel segment 2 and the subsequent grouting and forming of the tunnel bottom backfill layer 7. The design of the lower edge extending into the drainage channel can further optimize the water flow guidance path, reduce the retention of water at the corners of the channel wall, and improve drainage smoothness; at the same time, the pre-embedded trapezoidal steel channel 9... The inclined side of the steel channel 9 is at the same angle as the side wall of the drainage channel, so that it can be perfectly adapted to the isosceles trapezoidal cross section of the drainage channel 8, avoiding structural stress concentration caused by angular deviation. In addition, the trapezoidal steel channel 9 is fixedly connected to the bottom concrete slab by pre-embedded steel bars, which can strengthen the connection between the steel channel and the bottom slab, prevent the steel channel from loosening or falling off due to long-term water flow erosion or structural stress, and the rigidity of the steel channel can significantly improve the erosion resistance of the side wall of the drainage channel 8, preventing the concrete channel wall from being worn and cracked due to long-term water flow impact, thereby ensuring the long-term structural stability and drainage function reliability of the drainage channel.

[0045] like Figure 2As shown, the box culvert body 1 adopts a symmetrical design, including cable segments and pipe segments symmetrically arranged on both sides of the cable segments. The cable segments and pipe segments are prefabricated as a whole, and their top and bottom plates are continuously connected. The cable segments are provided with longitudinally connected cable trenches, and the pipe segments are provided with longitudinally connected pipes.

[0046] It should be noted that the box culvert body 1 consists of a central cable segment and symmetrically arranged pipe segments on both sides. This symmetrical functional zoning design ensures the overall stress balance of the box culvert and allows the power lines and drainage system to operate independently without interference, meeting the dual needs of power supply and water drainage during tunnel operation. Furthermore, the cable and pipe segments are prefabricated as a single unit rather than being spliced ​​in sections. This process completely avoids structural weaknesses that may arise from segmented connections, significantly improving the overall rigidity and deformation resistance of the box culvert body 1, while eliminating the cumbersome on-site splicing process, thus meeting the needs of efficient shield tunnel construction. The continuous connection between the top and bottom slabs further strengthens the continuity of the upper and lower structures of the box culvert, ensuring that the load can be evenly distributed along the entire box culvert and avoiding local stress concentration. Corresponding segments are equipped with longitudinally connected cable trenches and pipes. The cable trenches can accommodate the power lines required for tunnel operation, ensuring stable power supply to the equipment, while the pipes serve as dedicated paths during the operation period, achieving a deep integration of function and structure.

[0047] like Figure 2 As shown, the arc-shaped support 10 is arranged along the length of the base plate and is correspondingly arranged below the base plate of the cable trench. The radius of curvature of the outer arc surface of the arc-shaped support 10 is adapted to the radius of curvature of the inner arc surface of the shield tunnel segment 2, so that the arc-shaped support 10 can fit against the inner surface of the shield tunnel segment 2.

[0048] It should be noted that the arc-shaped support 10 is set along the length of the base plate and is located below the base plate of the cable trench. This design can specifically provide support for the cable segments. Since the cable segments need to accommodate power lines, the load is relatively concentrated. Continuous support along the length can ensure uniform stress distribution and avoid structural deformation in local areas due to load concentration. Moreover, the radius of curvature of the outer arc surface of the arc-shaped support 10 is matched with the radius of curvature of the inner arc surface of the shield segment 2, so that the arc-shaped support 10 can fit tightly with the inner surface of the shield segment 2. This not only ensures the contact stability between the support and the segment, but also evenly transfers the load of the cable segment to the shield segment 2 through the arc-shaped contact surface, avoiding the local stress concentration problem that may be caused by traditional support methods. At the same time, it is in line with the design concept of multi-functional precast box culverts to simplify construction and improve structural stability.

[0049] like Figure 3As shown, the arc-shaped support 10 is an arc-shaped protrusion structure integrally formed with the bottom plate, and its height is consistent with the design thickness of the tunnel bottom backfill layer 7; there are three hollow areas 5 in the bottom plate, which are respectively set on the bottom plates of the cable trench inside the box culvert body 1 and the pipes on both sides, and the edges of the hollow areas 5 are continuously attached with grout-stopping strips.

[0050] It should be noted that the arc-shaped support 10 is an arc-shaped protrusion structure integrally formed with the bottom plate. This forming method ensures that there are no weak points in the connection between the support and the bottom plate, significantly improving the bearing strength and deformation resistance of the support, and avoiding the loosening problems that may occur during separate installation. At the same time, the height of the support is limited to be consistent with the design thickness of the tunnel bottom backfill layer 7. This not only reserves precise space for the subsequent formation of the backfill layer through the pre-embedded grouting holes 6, but also allows the support and the backfill layer to share the load of the box culvert after the backfill layer has solidified, forming a synergistic force-bearing system and further enhancing the overall structural stability. The number of hollow areas 5 in the bottom plate is three, corresponding to the cable trench inside the box culvert body 1 and the two... The bottom plate of the side pipes is designed to precisely match the cable and pipe segments of the functional zones of the box culvert. By creating a hollowed-out bottom plate in the trench with a relatively small load, the self-weight of the box culvert can be reduced to the maximum extent, thus reducing the difficulty of hoisting inside the tunnel. At the same time, there is no need to backfill the hollowed-out area 5 with plain concrete, eliminating the pouring process in the narrow space and greatly simplifying the construction process. In addition, the edges of the hollowed-out area 5 are continuously fitted with grout-stopping strips, which can effectively prevent grouting materials from entering the interior of the hollowed-out area 5 when grouting is injected into the gap between the box culvert and the shield segment 2, avoiding the hollowed-out structure from being blocked, ensuring its weight reduction and functional adaptability, and at the same time ensuring the structural integrity of the box culvert bottom plate.

[0051] like Figure 4 As shown, the diameter and depth of the pre-embedded positioning pin hole 4 are adapted to the positioning pin of the lifting suction cup; during lifting, the positioning pin is inserted into the pin hole to realize the rapid alignment of the box culvert, and the suction cup is used to complete the lifting and placement.

[0052] It should be noted that the diameter and depth of the positioning pin hole 4 are strictly matched with the positioning pin of the lifting suction cup. This precise matching in size ensures that the positioning pin can be stably and seamlessly inserted into the pin hole, avoiding positioning loosening or displacement caused by mismatch during the lifting process, thus laying the foundation for subsequent precise lifting. At the same time, it refines the operation logic during lifting: by inserting the positioning pin into the pin hole, the alignment of the box culvert body 1 with the lifting equipment can be quickly achieved without repeatedly adjusting the position of the box culvert, greatly shortening the lifting alignment time in the narrow tunnel space. At the same time, in conjunction with the adsorption and fixing effect of the suction cup, the box culvert can be firmly fixed to the lifting equipment, which not only prevents the box culvert from shaking or falling off during the lifting process, but also allows the box culvert to be smoothly placed in the preset position after alignment. The overall effect is "rapid alignment + stable fixing", which effectively solves the problems of difficult alignment, long time consumption and poor stability in traditional box culvert lifting, and meets the core needs of efficient construction of multi-functional prefabricated box culverts.

[0053] like Figure 7 As shown, the longitudinal connecting bolt hole 3 includes an upper bolt hand hole 12 on the upper surface of the top plate and a lower bolt hand hole 11 on the lower surface. The upper bolt hand hole 12 and the lower bolt hand hole 11 are connected by an inclined channel. The axis of the inclined channel is consistent with the longitudinal inclined bolt installation axis, forming an operating space for the longitudinal connecting bolt to pass through.

[0054] It should be noted that the longitudinal connecting bolt holes 3 are divided into upper bolt hand holes 12 and lower bolt hand holes 11, which are respectively opened on the upper and lower surfaces of the roof plate. This layered layout can adapt to the operational requirements in the thickness direction of the roof plate, avoiding the problem that bolts cannot be inserted and tightened due to opening holes on only one side. It is especially suitable for the narrow construction space in shield tunnels, allowing construction workers to complete the bolt installation work from both the upper and lower sides of the roof plate. Moreover, the upper bolt hand holes 12 and the lower bolt hand holes 11 are connected by an inclined channel, and the axis of the inclined channel is consistent with the installation axis of the longitudinal inclined bolts. This design is both aimed at The inclined channel perfectly matches the inclined installation requirements of the longitudinal inclined bolts, avoiding the inability of bolts to be successfully inserted or the generation of additional stress after installation due to the deviation between the channel and the bolt axis. It also reduces the excessive weakening of the roof structure strength by the vertical channel. Compared with the vertical channel, the inclined channel can make more reasonable use of the internal space of the roof and reduce the damage to the stress section of the roof. At the same time, the complete operating space formed by the inclined channel can ensure that the bolts can be tightened smoothly after insertion, ensuring the connection stability of the longitudinal inclined bolts to adjacent box culvert segments, and further meeting the design requirements of "rapid assembly and reliable structure" of multi-functional prefabricated box culverts.

[0055] This embodiment describes the working principle and usage method of a multifunctional prefabricated box culvert system for medium-diameter water conveyance shield tunnels:

[0056] This embodiment provides a multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel. The box culvert body 1 is prefabricated as a whole. The arc-shaped support 10 of the bottom plate, with its outer arc surface adapted to the inner arc surface of the shield segment 2, replaces the traditional leveling bolts to complete radial self-leveling, reducing leveling operations. The hollow area 5 set in the bottom plate reduces its own weight and eliminates the secondary plain concrete backfilling process, simplifying construction. The longitudinal drainage channel at the lower end of the bottom plate forms a smooth drainage path through the concave isosceles trapezoidal holes and the pre-embedded trapezoidal steel channels 9 that fit the side walls, solving the problem of water accumulation during operation. The longitudinal connecting bolts and matching hand holes of the top plate achieve a stable connection between adjacent segments, and the pre-embedded positioning pin holes 4 ensure the accuracy of assembly. Finally, grout is injected into the gap between the box culvert and the shield segment 2 through the pre-embedded grouting holes 6 in the bottom plate to form the tunnel bottom backfill layer 7, so that the two are combined into an integral load-bearing structure, meeting the functional and load-bearing requirements of the medium-diameter water conveyance shield tunnel, and improving construction efficiency and operational reliability.

[0057] When in use, the entire box culvert body 1 is prefabricated in the factory first, and the hollow area 5 of the bottom plate, the arc support 10, the drainage channel (including the pre-embedded trapezoidal steel channel 9), the longitudinal connecting bolts and matching hand holes of the top plate, the pre-embedded positioning pin holes 4, and the pre-embedded grouting holes 6 of the bottom plate are integrated simultaneously to ensure that all components are precisely formed.

[0058] Subsequently, the prefabricated box culvert body 1 is transported to the shield tunnel construction area and hoisted into the preset position inside the tunnel using hoisting equipment. During the hoisting process, the outer arc surface of the arc support 10 at the bottom of the base plate naturally fits the inner arc surface of the shield segment 2, thus achieving the initial radial leveling of the box culvert body 1 without the need for additional leveling bolts.

[0059] Next, the adjacent box culvert segments are assembled: the positioning pin holes 4 on the top plate are precisely matched with the positioning pins of the adjacent segments to complete the positioning alignment between the segments; then, the longitudinal connecting bolts are inserted and tightened through the bolt hand holes 11 on the upper and lower sides of the top plate (connected by the inclined channel) to firmly connect the adjacent segments into a whole, ensuring the stability and integrity of the connection.

[0060] Finally, grouting material is injected into the gap between the box culvert body 1 and the shield tunnel segment 2 through the pre-embedded grouting holes 6 on the bottom plate. After the grouting material solidifies, it forms the tunnel bottom backfill layer 7. This backfill layer works in conjunction with the arc-shaped support 10 to ensure that the box culvert body 1 and the shield tunnel segment 2 are tightly bonded together, forming a stable load-bearing system. This completes the installation of a single box culvert section. The above steps are repeated to complete the laying of all box culvert sections. The entire process does not require secondary backfilling of the bottom plate hollow area 5, greatly simplifying the construction process.

[0061] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

[0062] In the description of this invention, it should be understood that the terms "upper", "lower", "upper end", "lower end", "upper surface", "lower surface", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and 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, and therefore should not be construed as a limitation of this invention.

[0063] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A multifunctional prefabricated box culvert system for medium-diameter water conveyance shield tunnels, characterized in that: It includes the box culvert body (1), shield tunnel segments (2) and tunnel bottom backfill layer (7); The bottom plate of the box culvert body (1) is provided with a hollow area (5), the top plate of the box culvert body (1) is provided with longitudinal connecting bolt holes (3) and pre-embedded positioning pin holes (4), the longitudinal connecting bolt holes (3) are used to connect adjacent box culvert sections, and the pre-embedded positioning pin holes (4) are adapted to the lifting suction cup; the bottom of the bottom plate is provided with an arc-shaped support (10) formed by an arc-shaped protrusion structure, the outer arc surface of the arc-shaped support (10) is adapted to the inner arc surface of the shield segment (2) to achieve radial leveling; the bottom plate is provided with a pre-embedded grouting hole (6) for grouting into the gap between the box culvert body (1) and the shield segment (2) to form a tunnel bottom backfill layer (7); the lower surface of the bottom plate is provided with an integrally formed concave drainage channel along the longitudinal direction, the drainage channel can drain the water accumulated in the tunnel during the operation period.

2. The multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 1, characterized in that: The wedge shape of the box culvert body (1) is adapted to the wedge shape of the shield tunnel segment (2), and the whole body is completely symmetrical. The width is matched with the ring width of the shield tunnel segment (2). By matching the wedge shape and symmetrical design, the box culvert body is adapted to the straight section of the tunnel and the curved section with different curve radii. With the matching of the width and the ring width, the box culvert body is able to be assembled synchronously with the shield tunnel segment (2) and the circumferential joints are aligned.

3. The multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 1, characterized in that: The drainage channel is a drainage trough (8) formed by the longitudinal concave bottom plate. The cross-section of the drainage trough (8) is an isosceles trapezoid, and a grout-stopping strip is continuously attached along the edge of the drainage trough (8) to prevent the grouting material from entering the drainage trough (8) and ensure smooth drainage after construction.

4. The multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 3, characterized in that: The inner side of the drainage trough (8) is pre-embedded with a trapezoidal steel channel (9) that fits against the side wall of the drainage trough (8). The upper edge of the trapezoidal steel channel (9) is flush with the lower surface of the bottom plate, and the lower edge extends into the drainage channel. The inclined side of the trapezoidal steel channel (9) is consistent with the inclination angle of the side wall of the drainage channel, and is fixedly connected to the bottom plate concrete by pre-embedded steel bars.

5. The multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 1, characterized in that: The box culvert body (1) includes cable segments and pipe segments symmetrically arranged on both sides of the cable segments. The cable segments and pipe segments are prefabricated as a whole, and their top and bottom plates are continuously connected. The cable segments are provided with longitudinally connected cable trenches, and the pipe segments are provided with longitudinally connected pipes.

6. The multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 5, characterized in that: The arc-shaped support (10) is set along the length of the base plate and is correspondingly set below the base plate of the cable trench. The outer arc surface curvature radius of the arc-shaped support (10) is adapted to the inner arc surface curvature radius of the shield tunnel segment (2), so that the arc-shaped support (10) can fit against the inner surface of the shield tunnel segment (2).

7. A multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 5, characterized in that: The arc-shaped support (10) is an arc-shaped protrusion structure integrally formed with the bottom plate, and its height is consistent with the design thickness of the tunnel bottom backfill layer (7); the number of the bottom plate hollow area (5) is three, which are respectively set on the bottom plate of the cable trench and the pipes on both sides inside the box culvert body (1), and the edge of the hollow area (5) is continuously attached with grout-stopping strips.

8. The multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 1, characterized in that: The diameter and depth of the pre-embedded positioning pin hole (4) are adapted to the positioning pin of the lifting suction cup; during lifting, the positioning pin is inserted into the pin hole to realize the rapid alignment of the box culvert, and the suction cup is used to complete the lifting and placement.

9. A multifunctional prefabricated box culvert system for a medium-diameter water conveyance shield tunnel as described in claim 1, characterized in that: The longitudinal connecting bolt hole (3) includes an upper bolt hand hole (12) on the upper surface of the top plate and a lower bolt hand hole (11) on the lower surface. The upper bolt hand hole (12) and the lower bolt hand hole (11) are connected by an inclined channel. The axis of the inclined channel is consistent with the longitudinal inclined bolt installation axis, forming an operating space for the longitudinal connecting bolt to pass through.

10. A construction method for a multifunctional prefabricated box culvert system in a medium-diameter water conveyance shield tunnel, characterized in that: Includes the following steps: S1. The box culvert body (1) of any one of claims 1-9 is prefabricated using a high-precision mold in the factory, and the concave drainage channel, the hollow area of ​​the bottom plate (5) and the arc support (10) are formed simultaneously. The longitudinal connecting bolt holes (3), the positioning pin holes (4) and the grouting holes (6) are pre-embedded, and the trapezoidal steel channel (9) and the matching pre-embedded steel bars are pre-embedded simultaneously. The grout-stopping strip is pre-installed at the edge of the drainage channel. S2. During shield tunnel excavation, the positioning pin of the hoisting suction cup is inserted into the pre-embedded positioning pin hole (4) of the box culvert, and the box culvert is hoisted into position. The initial radial leveling is completed by adapting the arc support (10) to the shield segment (2). S3. After the shield tunnel segment (2) is installed, the box culvert is assembled simultaneously so that the circumferential joint of the box culvert is aligned with the circumferential joint of the segment. The adjacent segments are fastened by longitudinal inclined bolts through the bolt handhole. S4. Grouting is injected into the gap between the box culvert and the segments through the pre-embedded grouting hole (6). The grout-stopping strip prevents the grout from entering the drainage channel and the hollow area (5). After grouting, the grouting hole (6) is sealed. S5. Seal the bolt manholes with cement grout and fill the circumferential joints of the box culvert with waterproof mortar. Repeat steps S2 through S5 to complete the installation of all box culverts.

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