Construction structure and construction method for backfilling aqueduct at the top of open-cut tunnel in existing river course

Abstract

This application relates to a construction structure and construction method for backfilling a flume at the top of an open-cut tunnel in an existing river channel. The solution includes a reinforced foamed concrete wall backfilling structure, a steel mesh-reinforced three-dimensional angle steel support, a rapid leveling device for a foamed concrete cushion, a in-situ elevation and binding jig for the reinforcement of the flume bottom slab, a in-situ binding jig for the reinforcement of the flume side wall, a segmented casting formwork system for the flume side wall, and a hanging formwork system for the top of the external reinforcing rib plate of the flume. The method is to use this construction structure for construction. This application can improve the structural safety, enhance the construction quality and efficiency, and ensure the safety and reliability of the whole construction process.

Description

Technical Field

[0001] The present application relates to the field of tunnel engineering and is applicable to the backfilling construction of open-cut tunnels, specifically to the construction structure and construction method of a flume for backfilling the top of an open-cut tunnel under an existing river channel. Background Art

[0002] After the construction of an open-cut tunnel passing under a river by the open-cut method, it is necessary to backfill the top of the tunnel and construct a flume above the tunnel to restore the river. If the conventional earth backfilling method is adopted, since the backfilled earth is not easily compacted, large-scale settlement is likely to occur in the backfilled earth in the later stage, resulting in damage to the flume and leakage of river water from the flume to the ground. Under the long-term scouring action of the river flow in the river channel, it is easy to hollow out the backfilled earth at the top of the tunnel, and the river water seeps into the soil outside the tunnel, thus increasing the risk of tunnel leakage. Therefore, it is necessary to innovate the earth backfilling and flume construction technologies above the open-cut tunnel passing under the river. After ensuring the water passing capacity of the restored existing river channel, the safety of the tunnel under the river channel also needs to be ensured.

[0003] In view of this, aiming at the deficiencies in the previous backfilling construction of open-cut tunnels, there is an urgent need for a new construction method for backfilling a lightweight foamed concrete flume at the top of an open-cut tunnel in the existing river channel area to improve the structural safety, construction quality and efficiency, and ensure the safety and reliability of the whole construction process. Summary of the Invention

[0004] The purpose of the present application is to provide a construction structure and construction method for backfilling a flume at the top of an open-cut tunnel in an existing river channel in view of the above problems existing in the prior art.

[0005] To achieve the above application purpose, the present application adopts the following technical solutions: The construction structure for backfilling a flume at the top of an open-cut tunnel in an existing river channel includes a reinforced foamed concrete wall backfilling structure, a steel mesh reinforced three-dimensional angle steel support, a rapid leveling device for a foamed concrete cushion, a in-situ elevation binding jig for the bottom slab steel bars of the flume, a in-situ binding jig for the side wall steel bars of the flume, a segmented pouring formwork system for the side walls of the flume, and a hanging formwork system for the top of the external reinforcing ribs of the flume;

[0006] The reinforced foamed concrete wall backfilling structure includes an open-cut tunnel, foamed concrete and a steel mesh. The open-cut tunnel is provided with a flume at the place passing through the existing river channel, and the steel mesh and the foamed concrete are backfilled above the open-cut tunnel;

[0007] The steel mesh reinforced three-dimensional angle steel support connects the steel mesh and the foamed concrete and is used to support and reinforce the steel mesh and the foamed concrete;

[0008] The rapid leveling device for the foamed concrete cushion is arranged above the foamed concrete and is used for leveling the foamed concrete cushion laid above the foamed concrete;

[0009] The in-situ elevation and binding rack for the aqueduct bottom slab reinforcement is arranged on the top of the foamed concrete cushion after leveling operation, which is used to facilitate the operation of binding the reinforcement;

[0010] The in-situ binding rack for the aqueduct side wall reinforcement is arranged on the top of the foamed concrete cushion after leveling operation, which is used to facilitate the operation of binding the reinforcement;

[0011] The segmented casting formwork system for the aqueduct side wall is used for the construction of the aqueduct side wall above the aqueduct, including the first section of side wall, the first section of formwork, the second section of formwork, the second section of side wall and steel pipes. The first section of formwork and the second section of formwork are respectively arranged on both sides of the first section of side wall and the second section of side wall, and the steel pipes are respectively arranged on the outer sides of the first section of formwork and the second section of formwork;

[0012] The top suspension formwork system for the outer strengthening rib plate of the aqueduct is used for strengthening the support of the segmented casting formwork system of the aqueduct side wall, including a horizontal support rod, a suspension rod, a triangular side form, a top form, a U-shaped perforated clamp and a screw rod. The horizontal support rod is fixed on one side of the outer side of the side wall through a U-shaped fixing piece. One end of the suspension rod is fixed on the horizontal support rod, and the other end is fixed on the triangular side form. The triangular side form is arranged on both sides of the strengthening rib plate, and the top form is arranged between the triangular side forms. The U-shaped perforated clamp fixes the two-sided triangular side forms and the top form, and is tightened by fixing the screw hole passing through the screw rod with a rectangular nut.

[0013] Further, the steel mesh reinforced three-dimensional angle steel support includes L-shaped angle steel, support steel and transverse connecting steel. The steel mesh is connected and fixed to the L-shaped angle steel through fixing wires. The L-shaped angle steel is fixed in the foamed concrete. The support steel is arranged on the L-shaped angle steel, and the transverse connecting steel connects two relatively arranged L-shaped angle steels.

[0014] Further, the quick leveling device for the foamed concrete cushion includes side forms, moving tracks, movable support vertical rods, leveling beams, hanging rods, scraping plates and scraping plate fixing pieces. The foamed concrete cushion is arranged on the structural roof slab, and the structural roof slab is placed on the top of the steel mesh. The side forms are arranged on both sides of the foamed concrete cushion, the moving tracks are arranged on both sides of the side forms, the leveling beams are arranged on the moving tracks through the movable support vertical rods, the scraping plates are connected to the hanging rods through the scraping plate fixing pieces, and the hanging rods are fixed on the leveling beams.

[0015] Further, the in-situ elevation and binding rack for the aqueduct bottom slab reinforcement includes a steel vertical frame, a steel horizontal frame, steel bar hoop and support steel bars. The steel vertical frame is arranged on the foamed concrete cushion, the steel horizontal frame is fixed on the steel vertical frame, the steel bar hoops are fixed at equal intervals on the steel horizontal frame, and the support steel bars are arranged in each steel bar hoop.

[0016] Furthermore, the in-situ binding support for the side wall steel bars of the aqueduct includes steel backing plates, fixed grooves, vertical steel frames, supporting steel pipes, steel pipe fixing rings, and inclined supports. The steel backing plates are fixed to the foam concrete cushion through backing plate fixing nails. The fixed grooves are arranged on the steel backing plates. The vertical steel frames are fixed in the fixed grooves. The steel pipe fixing rings are fixed on the vertical steel frames. The supporting steel pipes are fixed in the steel pipe fixing rings. One end of the inclined support is fixed on the vertical steel frame, and the other end is fixed on the steel backing plate.

[0017] Furthermore, the steel pipe fixing rings are evenly spaced and fixed on the vertical steel frames.

[0018] Furthermore, the steel pipes are respectively fixed to the outsides of the first-section formwork and the second-section formwork through tie bolts.

[0019] The construction method for backfilling the aqueduct at the top of the existing riverbed open-cut tunnel is characterized by including the following steps:

[0020] S00. Construction preparation: Conduct surveying and setting out, lay out survey points, and inspect and accept the construction materials entering the site.

[0021] S10. River interception and diversion: Intercept the existing river on both sides of the open-cut tunnel. Before the interception construction, set up an open channel to divert the river, divert the river water into the open channel, and then pump out the water within the cofferdam.

[0022] S20. Earth excavation: The foundation pit excavation is carried out symmetrically in layers and sections until the excavation is completed.

[0023] S30. Construction of the tunnel main structure: After the excavation is completed, conduct inspections before pouring the main structure concrete, clean all the sundries inside the formwork, and then pour the concrete.

[0024] S40. Foam concrete backfilling: After the construction of the tunnel main structure is completed, carry out the backfilling construction operation for the foundation pit at the top of the tunnel. The steel mesh and foam concrete are backfilled above the open-cut tunnel. The steel mesh is connected and fixed to the L-shaped angle steel through fixing wires. The L-shaped angle steel is fixed in the foam concrete. The supporting steel section is arranged on the L-shaped angle steel. The transverse connecting steel section connects two L-shaped angle steels, and the backfilling construction is carried out layer by layer.

[0025] S50. Construction of the foam concrete cushion: Assemble the quick leveling device for the foam concrete cushion, set the side formwork on both sides of the foam concrete cushion, set the moving track on both sides of the side formwork, set the leveling beam on the moving track through the movable support vertical rods, connect the scraping plate to the hanging rod through the scraping plate fixing part, fix the hanging rod on the leveling beam, and pour the foam concrete cushion on the structural roof slab and level it with the quick leveling device for the foam concrete cushion.

[0026] S60, Aqueduct construction: The bottom slab steel bars are tied by the in-situ elevation tying jig for the bottom slab of the aqueduct. The steel vertical frames are placed on the foam concrete cushion layer, the steel horizontal frames are fixed to the steel vertical frames, the steel bar collars are fixed at equal intervals on the steel horizontal frames, the support steel bars are placed inside the steel bar collars, and the steel bar tying construction is completed on the in-situ elevation tying jig for the bottom slab of the aqueduct;

[0027] The side wall steel bars are tied by the in-situ tying jig for the side wall of the aqueduct. The steel backing plates are fixed to the foam concrete cushion layer by the backing plate fixing nails, the vertical steel frames are fixed in the fixing grooves of the steel backing plates, the steel pipe fixing rings are evenly spaced and fixed on the vertical steel frames, the supporting steel pipes are fixed inside the steel pipe fixing rings, one end of the inclined support is fixed to the vertical steel frame, and the other end is fixed to the steel backing plate. The steel bar tying construction is completed on the in-situ tying jig for the side wall of the aqueduct;

[0028] S70, Side wall formwork construction: The side wall formwork construction is carried out through the segmented pouring formwork system for the side wall of the aqueduct. The first section formwork and the second section formwork are respectively arranged on both sides of the first section side wall and the second section side wall. The steel pipes are arranged outside all the formworks and fixed by the tie rods. After the construction is completed, the concrete is poured and cured;

[0029] S80, Outer strengthening rib plate construction of the aqueduct: Formwork is supported at the designated position. The horizontal support rods are fixed to one side of the outer side wall of the side wall by the U-shaped fixing parts. One end of the suspension rod is fixed to the horizontal support rod, and the other end is fixed to the triangular side formwork. The triangular side formwork is arranged on both sides of the strengthening rib plate. The top formwork is arranged between the adjacent triangular side formworks. The U-shaped perforated clamps fix the two-sided triangular side formworks and the top formwork and are tightened by fixing the screw holes of the screws passing through the rectangular nuts. After completion, the concrete is poured and the formwork is removed after the strength reaches the requirement;

[0030] S90, River restoration: After the construction is completed and inspected and accepted, the equipment and machinery are removed and withdrawn, and the river restoration operation is carried out until the construction is completed.

[0031] Further, in step S10, by driving double-row steel sheet piles along the upstream and downstream, the river water is introduced into the open channel, and then the water inside the cofferdam is pumped out by the pumping equipment.

[0032] Further, in step S90, a small rammer is used to tamp and compact the connection between the river dam and the aqueduct. At the same time, the soil is filled outside the aqueduct, the steel sheet pile cofferdams on both sides of the river are removed, the river water flows through the aqueduct, and the function of the existing river channel is restored.

[0033] This application has the following features and beneficial effects:

[0034] 1. Compared with the prior art, the present application uses reinforced foamed concrete backfill and a three-dimensional angle steel support reinforced with a steel mesh for backfill construction. The steel mesh has good fixing effect and stable structure, which improves the tensile strength of the foamed concrete, reduces the pressure above the tunnel, and ensures the safety of the tunnel.

[0035] 2. Compared with the prior art, the present application uses a rapid leveling device for the foamed concrete cushion to carry out cushion leveling construction. The construction speed is fast, the leveling effect is good, and the input of manpower is reduced.

[0036] 3. Compared with the prior art, the present application uses a in-situ elevation and binding jig for the bottom slab steel bars of the aqueduct and a in-situ binding jig for the side wall steel bars of the aqueduct to carry out steel bar binding construction. The positioning accuracy of the steel bar binding is high, the construction speed is fast, it is convenient for personnel to operate, and the quality of the steel bar binding construction is ensured.

[0037] 4. Compared with the prior art, the present application uses a segmented casting formwork system for the side wall of the aqueduct and a top suspension formwork system for the external strengthening rib plate of the aqueduct to carry out formwork construction. The construction speed of the segmented formwork for the side wall is fast, and the forming effect of the rib plate is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic diagram of the lightweight foamed concrete backfill aqueduct structure at the top of the open-cut tunnel in the existing river channel area of the present invention

[0039] Figure 2 is a schematic diagram of the reinforced foamed concrete backfill structure of the present invention

[0040] Figure 3 is a front view of the three-dimensional angle steel support structure reinforced with a steel mesh

[0041] Figure 4 is a side view of the three-dimensional angle steel support structure reinforced with a steel mesh

[0042] Figure 5 is a front view of the structure of the rapid leveling device for the foamed concrete cushion

[0043] Figure 6 is a side view of the structure of the rapid leveling device for the foamed concrete cushion

[0044] Figure 7 is a schematic diagram of the structure of the in-situ elevation and binding jig for the bottom slab steel bars of the aqueduct

[0045] Figure 8 is a front view of the structure of the in-situ binding jig for the side wall steel bars of the aqueduct

[0046] Figure 9 is a side view of the structure of the in-situ binding jig for the side wall steel bars of the aqueduct

[0047] Figure 10 is a schematic diagram of the segmented casting formwork system for the side wall of the aqueduct

[0048] Figure 11 It is the front view of the hanging formwork system structure at the top of the outer strengthening rib plate of the aqueduct

[0049] Figure 12 It is the side view of the hanging formwork system structure at the top of the outer strengthening rib plate of the aqueduct

[0050] Figure 13 It is the schematic diagram of the U-shaped perforated clamp structure

[0051] In the figure: 1. Existing river course; 2. Open-cut tunnel; 3. Aqueduct; 4. Steel mesh; 5. Foamed concrete; 6. Strengthening rib plate; 7. Foamed concrete cushion; 8. Structural roof slab; 9. L-shaped angle steel; 10. Support steel section; 11. Fixed wire; 12. Transverse connecting steel section; 14. Side formwork; 15. Moving track; 16. Movable support vertical rod; 17. Leveling beam; 18. Hanging rod; 19. Screed board; 20. Screed board fixing part; 21. Steel vertical frame; 22. Steel horizontal frame; 23. Steel reinforcement hoop; 24. Support steel bar; 25. Steel backing plate; 26. Fixed groove; 27. Backing plate fixing nail; 28. Vertical steel frame; 29. Laying steel pipe; 30. Steel pipe fixing ring; 31. Inclined support; 32. First section of side wall; 33. First section of formwork; 34. Second section of formwork; 35. Second section of side wall; 36. Steel pipe; 37. Tie rod; 38. Side wall; 39. U-shaped fixing part; 40. Horizontal support rod; 41. Suspension rod; 42. Triangular side formwork; 43. Top formwork; 44. U-shaped perforated clamp; 45. Screw hole; 46. Rectangular nut; 47. Screw Specific implementation manners

[0052] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of the present application.

[0053] Those skilled in the art should understand that in the disclosure of the present application, the orientation or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the accompanying drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limiting the present application.

[0054] The construction structure for backfilling the top of an existing open-cut tunnel with an aqueduct includes a reinforced foamed concrete wall backfilling structure, a steel mesh-reinforced three-dimensional angle steel support, a quick leveling device for the foamed concrete cushion, a in-situ elevation and binding jig for the aqueduct bottom slab steel bars, a in-situ binding jig for the aqueduct side wall steel bars, a segmented casting formwork system for the aqueduct side wall, and a hanging formwork system for the outer strengthening rib plate of the aqueduct;

[0055] Specifically, as Figure 1-2 shown, the reinforced foamed concrete wall backfilling structure includes an open-cut tunnel 2, foamed concrete 5, and a steel mesh 4. The open-cut tunnel 2 is provided with an aqueduct 3 where it passes through the existing river channel 1, and the steel mesh 4 and the foamed concrete 5 are backfilled above the open-cut tunnel 2;

[0056] Specifically, the steel mesh-reinforced three-dimensional angle steel support connects the steel mesh 4 and the foamed concrete 5, and is used to support and reinforce the steel mesh 4 and the foamed concrete 5;

[0057] In this embodiment, as Figure 2-4 shown, the steel mesh-reinforced three-dimensional angle steel support includes an L-shaped angle steel 9, a support steel section 10, and a transverse connecting steel section 12. The steel mesh 4 is connected and fixed to the L-shaped angle steel 9 through a fixing wire 11. The L-shaped angle steel 9 is fixed in the foamed concrete 5. The support steel section 10 is arranged on the L-shaped angle steel 9, and the transverse connecting steel section 12 connects two relatively arranged L-shaped angle steels 9.

[0058] Specifically, the quick leveling device for the foamed concrete cushion is arranged above the foamed concrete 5, and is used to level the foamed concrete cushion 7 laid above the foamed concrete 5;

[0059] In this embodiment, as Figure 5-6 shown, the quick leveling device for the foamed concrete cushion includes side forms 14, moving tracks 15, movable support vertical bars 16, leveling beams 17, hanging bars 18, scraping plates 19, and scraping plate fixing parts 20. The foamed concrete cushion 7 is arranged on the structural roof slab 8, and the structural roof slab 8 is placed on the top of the steel mesh 4. The side forms 14 are arranged on both sides of the foamed concrete cushion 7. The moving tracks 15 are arranged on both sides of the side forms 14. The leveling beams 17 are arranged on the moving tracks 15 through the movable support vertical bars 16. The scraping plates 19 are connected to the hanging bars 18 through the scraping plate fixing parts 20, and the hanging bars 18 are fixed to the leveling beams 17.

[0060] Specifically, the in-situ elevation and binding jig for the aqueduct bottom slab steel bars is arranged on the top of the foamed concrete cushion 7 after leveling operation, and is used to facilitate the binding of steel bars;

[0061] In this embodiment, as Figure 7As shown in the figure, the in-situ elevation and binding support for the aqueduct bottom slab reinforcement includes a steel vertical frame 21, a steel horizontal frame 22, a steel bar hoop 23, and a support steel bar 24. The steel vertical frame 21 is arranged on the foam concrete cushion layer 7, the steel horizontal frame 22 is fixed on the steel vertical frame 21, the steel bar hoops 23 are fixed on the steel horizontal frame 22 at equal intervals, and the support steel bar 24 is arranged inside each steel bar hoop 23.

[0062] Specifically, the in-situ binding support for the aqueduct side wall reinforcement is arranged on the top of the foam concrete cushion layer 7 after leveling operation, which is convenient for binding the steel bars.

[0063] In this embodiment, as Figure 8-9 shown, the in-situ binding support for the aqueduct side wall reinforcement includes a steel backing plate 25, a fixing groove 26, a vertical steel framework 28, a supporting steel pipe 29, a steel pipe fixing ring 30, and an inclined support 31. The steel backing plate 25 is fixed on the foam concrete cushion layer 7 through a backing plate fixing nail 27, the fixing groove 26 is arranged on the steel backing plate 25, the vertical steel framework 28 is fixed in the fixing groove 26, the steel pipe fixing rings 30 are evenly spaced and fixed on the vertical steel framework 28, the supporting steel pipe 29 is fixed in the steel pipe fixing ring 30, and one end of the inclined support 31 is fixed on the vertical steel framework 28 and the other end is fixed on the steel backing plate 25.

[0064] Specifically, as Figure 10 shown, the segmented casting formwork system for the aqueduct side wall is used for constructing the aqueduct side wall above the aqueduct 3, and includes a first-section side wall 32, a first-section formwork 33, a second-section formwork 34, a second-section side wall 35, and a steel pipe 36. The first-section formwork 33 and the second-section formwork 34 are respectively arranged on both sides of the first-section side wall 32 and the second-section side wall 35, and the steel pipes 36 are respectively fixed on the outer sides of the first-section formwork 33 and the second-section formwork 34 through tie rods 37.

[0065] Specifically, as Figure 11-13 shown, the top suspension formwork system for the outer strengthening rib plate of the aqueduct is used for supporting and strengthening the segmented casting formwork system of the aqueduct side wall, and includes a horizontal support rod 40, a suspension rod 41, a triangular side form 42, a top form 43, a U-shaped perforated clamp 44, and a screw rod 47. The horizontal support rod 40 is fixed on one outer side of the side wall 38 through a U-shaped fixing part 39, one end of the suspension rod 41 is fixed on the horizontal support rod 40 and the other end is fixed on the triangular side form 42. The triangular side form 42 is arranged on both sides of the strengthening rib plate 6, the top form 43 is arranged between the triangular side forms 42, the U-shaped perforated clamp 44 fixes the two-sided triangular side forms 42 and the top form 43, and is tightened through a rectangular nut 46 fixing the screw rod hole 45 passing through the screw rod 47.

[0066] Embodiment 2

[0067] Based on the same concept as Embodiment 1, the construction method for backfilling the aqueduct at the top of the existing riverbed open-cut tunnel includes the following steps:

[0068] S00, Construction Preparation: Conduct surveying and setting out, lay out survey points, implement on-site traffic control, keep the site clean and tidy, and inspect and accept the construction materials entering the site;

[0069] S10, River Interception and Diversion: Intercept the existing river 1 on both sides of the open-cut tunnel 2. Before the interception construction, set up an open channel to divert the river. By driving double-row steel sheet piles along the upstream and downstream, divert the river water into the open channel, then use pumping equipment to pump out the water inside the cofferdam, divert the river water into the open channel, and then pump out the water inside the cofferdam;

[0070] S20, Earth Excavation: The foundation pit excavation is carried out symmetrically in layers and sections until the excavation is completed;

[0071] In this embodiment, an ordinary excavator is used for the construction of the upper part of the foundation pit, and a grab bucket or a long-arm excavator is used for the excavation of the middle part.

[0072] S30, Tunnel Main Structure Construction: After the excavation is completed, conduct inspections before pouring the main structure concrete (inspect the supports, formworks, steel bar protection layers, embedded parts, and concealed engineering parts), and clean all the debris inside the formworks, and then pour the concrete;

[0073] S40, Foamed Concrete Backfilling: After the tunnel main structure construction is completed, carry out the backfilling construction operation of the foundation pit on the top of the tunnel. The steel mesh 4 and the foamed concrete 5 are backfilled on the upper part of the open-cut tunnel. The steel mesh 4 is connected and fixed to the L-shaped angle steel 9 through the fixing wire 11. The L-shaped angle steel 9 is fixed inside the foamed concrete 5. The support steel 10 is arranged on the L-shaped angle steel 9, and the transverse connecting steel 12 connects two L-shaped angle steels 9, and the backfilling construction is carried out layer by layer;

[0074] S50, Construction of Foamed Concrete Cushion 7: Assemble the quick leveling device for the foamed concrete cushion, set the side form 14 on both sides of the foamed concrete cushion 7, set the moving track 15 on both sides of the side form 14, set the leveling beam 17 on the moving track 15 through the movable support vertical rod 16, connect the scraping plate 19 to the hanging rod 18 through the scraping plate fixing part 20, fix the hanging rod 18 on the leveling beam 17, and pour the foamed concrete cushion 7 on the structural roof 8, and use the quick leveling device for the foamed concrete cushion to level (smooth);

[0075] S60, Construction of Aqueduct 3: Through the in-situ elevation and binding rack for the bottom steel bars of the aqueduct, carry out the bottom steel bars (attached Figure 2For the bottom slab under the middle aqueduct 3, during construction, steel bar binding must be carried out first (steel bar binding is a necessary conventional operation). After binding, the steel vertical frame 21 is placed on the foam concrete cushion layer 7, the steel horizontal frame 22 is fixed to the steel vertical frame 21, the steel bar hoop 23 is fixed at equal intervals on the steel horizontal frame 22, the support steel bars 24 are placed inside the steel bar hoop 23, and the steel bar binding construction is completed on the in-situ elevation binding jig for the aqueduct bottom slab steel bars.

[0076] For the steel bar binding of the side wall 38, it is carried out through the in-situ binding jig for the aqueduct side wall steel bars. The steel backing plate 25 is fixed to the foam concrete cushion layer 7 through the backing plate fixing nails 27, the vertical steel framework 28 is fixed in the fixing groove 26 of the steel backing plate 25, the steel pipe fixing rings 30 are evenly spaced and fixed on the vertical steel framework 28, the supporting steel pipes 29 are fixed inside the steel pipe fixing rings 30, one end of the inclined support 31 is fixed to the vertical steel framework 28, and the other end is fixed to the steel backing plate 25. The steel bar binding construction is completed on the in-situ binding jig for the aqueduct side wall steel bars.

[0077] S70, Side wall formwork construction: The side wall formwork construction is carried out through the segmented pouring formwork system for the aqueduct side wall. The first-section formwork 33 and the second-section formwork 34 are respectively arranged on both sides of the first-section side wall 32 and the second-section side wall 35. The steel pipes 36 are arranged outside all the formworks (including the first-section formwork 33, the second-section formwork 34 and the remaining formworks) and fixed through the tie rods 37. After the construction is completed, concrete is poured and cured.

[0078] S80, Construction of the outer strengthening rib plates of the aqueduct: Formwork is supported at the specified position. The horizontal support rod 40 is fixed to the outside of the side wall 38 (the complete side wall formed by the first-section side wall 32, the second-section side wall 35 and the remaining sections) through the U-shaped fixing parts 39. One end of the hanging rod 41 is fixed to the horizontal support rod 40, and the other end is fixed to the triangular side form 42. The triangular side form 42 is arranged on both sides of the strengthening rib plate 6. The top form 43 is arranged between adjacent triangular side forms 42. The U-shaped perforated clamps 44 fix the two-sided triangular side forms 42 and the top form 43 and are tightened through the rectangular nuts 46 fixing the screw holes 45 of the through screw 47. After completion, concrete is poured and the formwork is removed after the strength reaches the requirement.

[0079] S90, River restoration: After the construction is completed and inspected and accepted, the equipment and machinery are removed and withdrawn, and the river restoration operation is carried out. A small ramming machine is used to ram and compact the connection between the river dam and the aqueduct. At the same time, soil is filled outside the aqueduct, the steel sheet pile cofferdams on both sides of the river are removed, and the river water flows through the aqueduct to restore the function of the existing river until the construction is completed.

[0080] The parts not detailed in this application are prior art, so this application does not detail them.

[0081] It will be understood that the term "a" should be construed as "at least one" or "one or more". That is, in one embodiment, the number of an element may be one, while in other embodiments, the number of the element may be multiple. The term "a" should not be construed as a limitation on the number.

[0082] Although many professional terms are used herein, the possibility of using other terms is not excluded. These terms are used only to more conveniently describe and explain the essence of the present application; interpreting them as any additional limitation is contrary to the spirit of the present application.

[0083] The present application is not limited to the above-mentioned best mode. Anyone can obtain other various forms of products under the inspiration of the present application. However, no matter what changes are made in its shape or structure, as long as it has a technical solution that is the same as or similar to that of the present application, it falls within the protection scope of the present application.

Claims

1. Construction structure for backfilling aqueduct at the top of an open-cut tunnel in an existing river channel, Characterized in that, It includes a reinforced foamed concrete wall-back filling structure, a steel mesh-reinforced three-dimensional angle steel support, a rapid leveling device for foamed concrete cushion, a in-situ elevation and binding jig for aqueduct bottom slab steel bars, a in-situ binding jig for aqueduct side wall steel bars, a segmented casting formwork system for aqueduct side wall and a hanging formwork system for the top of the external strengthening rib plate of the aqueduct; The reinforced foamed concrete wall-back filling structure includes an open-cut tunnel (2), foamed concrete (5) and a steel mesh (4). The open-cut tunnel (2) is provided with an aqueduct (3) at the place passing through the existing river channel (1). The steel mesh (4) and the foamed concrete (5) are backfilled above the open-cut tunnel (2); The steel mesh-reinforced three-dimensional angle steel support connects the steel mesh (4) and the foamed concrete (5) and is used to support and reinforce the steel mesh (4) and the foamed concrete (5). The steel mesh-reinforced three-dimensional angle steel support includes an L-shaped angle steel (9), a support steel section (10) and a transverse connecting steel section (12). The steel mesh (4) is connected and fixed to the L-shaped angle steel (9) through fixing wires (11). The L-shaped angle steel (9) is fixed in the foamed concrete (5). The support steel section (10) is arranged on the L-shaped angle steel (9). The transverse connecting steel section (12) connects two relatively arranged L-shaped angle steels (9); The rapid leveling device for foamed concrete cushion is arranged above the foamed concrete (5) and is used to level the foamed concrete cushion (7) laid above the foamed concrete (5); The in-situ elevation and binding jig for aqueduct bottom slab steel bars is arranged at the top of the foamed concrete cushion (7) after leveling operation and is used to facilitate the binding of steel bars; The in-situ binding jig for aqueduct side wall steel bars is arranged at the top of the foamed concrete cushion (7) after leveling operation and is used to facilitate the binding of steel bars; The segmented casting formwork system for aqueduct side wall is used for the construction of the aqueduct side wall above the aqueduct (3) and includes a first-section side wall (32), a first-section formwork (33), a second-section formwork (34), a second-section side wall (35) and steel pipes (36). The first-section formwork (33) and the second-section formwork (34) are respectively arranged on both sides of the first-section side wall (32) and the second-section side wall (35). The steel pipes (36) are respectively arranged on the outer sides of the first-section formwork (33) and the second-section formwork (34). The steel pipes (36) are respectively fixed to the outer sides of the first-section formwork (33) and the second-section formwork (34) through tie rods (37); The hanging formwork system at the top of the external stiffening rib plate of the aqueduct is used to support and strengthen the formwork system for segmented pouring of the side wall of the aqueduct, and includes a horizontal support rod (40), a suspension rod (41), a triangular side form (42), a top form (43), a U-shaped perforated clamp (44) and a screw rod (47). The horizontal support rod (40) is fixed to one side outside the side wall (38) through a U-shaped fixing member (39). One end of the suspension rod (41) is fixed to the horizontal support rod (40), and the other end is fixed to the triangular side form (42). The triangular side form (42) is arranged on both sides of the stiffening rib plate (6). The top form (43) is arranged between the triangular side forms (42). The U-shaped perforated clamp (44) fixes the triangular side forms (42) and the top form (43) on both sides, and is tightened through a rectangular nut (46) fixing the screw hole (45) passing through the screw rod (47).

2. The construction structure of the aqueduct for backfilling on the top of the existing river channel open-cut tunnel according to claim 1, characterized in that, the quick leveling device for the foamed concrete cushion includes side forms (14), moving tracks (15), movable support vertical rods (16), leveling beams (17), hanging rods (18), scraping plates (19) and scraping plate fixing members (20). The foamed concrete cushion (7) is arranged on the structural roof slab (8). The structural roof slab (8) is placed on the top of the steel mesh (4). The side forms (14) are arranged on both sides of the foamed concrete cushion (7). The moving tracks (15) are arranged on both sides of the side forms (14). The leveling beams (17) are arranged on the moving tracks (15) through the movable support vertical rods (16). The scraping plates (19) are connected to the hanging rods (18) through the scraping plate fixing members (20). The hanging rods (18) are fixed to the leveling beams (17).

3. The construction structure of the aqueduct for backfilling on the top of the existing river channel open-cut tunnel according to claim 1, characterized in that, the in-situ elevation binding rack for the bottom slab steel bars of the aqueduct includes steel vertical frames (21), steel horizontal frames (22), steel bar hoop clamps (23) and support steel bars (24). The steel vertical frames (21) are arranged on the foamed concrete cushion (7). The steel horizontal frames (22) are fixed to the steel vertical frames (21). The steel bar hoop clamps (23) are equidistantly fixed to the steel horizontal frames (22). The support steel bars (24) are arranged in each steel bar hoop clamp (23).

4. The construction structure of the aqueduct for backfilling on the top of the existing river channel open-cut tunnel according to claim 3, characterized in that, The in-situ binding fixture for the side wall steel bars of the aqueduct comprises a steel backing plate (25), a fixing groove (26), a vertical steel framework (28), a supporting steel pipe (29), a steel pipe fixing ring (30) and an inclined support (31). The steel backing plate (25) is fixed on the foam concrete cushion layer (7) through cushion fixing nails (27). The fixing groove (26) is arranged on the steel backing plate (25). The vertical steel framework (28) is fixed in the fixing groove (26). The steel pipe fixing ring (30) is fixed on the vertical steel framework (28). The supporting steel pipe (29) is fixed in the steel pipe fixing ring (30). One end of the inclined support (31) is fixed on the vertical steel framework (28), and the other end is fixed on the steel backing plate (25).

5. The construction structure of the aqueduct for backfilling the top of the open-cut tunnel in the existing river channel according to claim 4, characterized in that, the steel pipe fixing rings (30) are evenly spaced and fixed on the vertical steel framework (28).

6. The construction method of the construction structure of the aqueduct for backfilling the top of the open-cut tunnel in the existing river channel according to any one of claims 1-5, characterized in that, it comprises the following steps: S00, construction preparation: measuring and setting out, laying out measuring points, and inspecting and accepting the construction materials entering the site; S10, river channel interception and diversion: intercept the existing river channel (1) on both sides of the open-cut tunnel (2). Before the interception construction, set up an open channel to divert the river, divert the river water into the open channel, and then pump out the water in the cofferdam; S20, earth excavation: the foundation pit excavation is carried out symmetrically in layers and sections until the excavation is completed; S30, tunnel main structure construction: after the excavation is completed, check before pouring the main structure concrete, and clean all the sundries in the formwork, and then pour the concrete; S40, foam concrete backfilling: after the tunnel main structure construction is completed, carry out the backfilling construction operation of the foundation pit at the top of the tunnel. The steel mesh sheet (4) and the foam concrete (5) are backfilled above the open-cut tunnel. The steel mesh sheet (4) is connected and fixed with the L-shaped angle steel (9) through fixing wires (11). The L-shaped angle steel (9) is fixed in the foam concrete (5). The supporting steel (10) is arranged on the L-shaped angle steel (9). The transverse connecting steel (12) connects two L-shaped angle steels (9), and the backfilling construction is carried out layer by layer; S50, construction of the foam concrete cushion layer (7): assemble the quick leveling device for the foam concrete cushion layer, arrange the side formwork (14) on both sides of the foam concrete cushion layer (7), arrange the moving track (15) on both sides of the side formwork (14), arrange the leveling beam (17) on the moving track (15) through the movable supporting vertical rod (16), connect the scraping plate (19) with the hanging rod (18) through the scraping plate fixing part (20), fix the hanging rod (18) on the leveling beam (17), and pour the foam concrete cushion layer (7) on the structural roof (8), and level it by using the quick leveling device for the foam concrete cushion layer; S60, Construction of the aqueduct (3): The bottom steel bars of the aqueduct are tied by means of an in-situ elevation tying bench for the bottom steel bars of the aqueduct, with the steel vertical frames (21) placed on the foamed concrete cushion layer (7), the steel horizontal frames (22) fixed to the steel vertical frames (21), the steel bar hoop sleeves (23) fixed at equal intervals to the steel horizontal frames (22), and the support steel bars (24) placed inside the steel bar hoop sleeves (23). The steel bar tying construction is completed on the in-situ elevation tying bench for the bottom steel bars of the aqueduct; The sidewall steel bars of the aqueduct are tied by means of an in-situ tying bench for the sidewall steel bars of the aqueduct, with the steel backing plates (25) fixed to the foamed concrete cushion layer (7) by means of backing plate fixing nails (27), the vertical steel frames (28) fixed inside the fixing grooves (26) of the steel backing plates (25), the steel pipe fixing rings (30) fixed at uniform intervals to the vertical steel frames (28), the supporting steel pipes (29) fixed inside the steel pipe fixing rings (30), one end of the inclined supports (31) fixed to the vertical steel frames (28) and the other end fixed to the steel backing plates (25). The steel bar tying construction is completed on the in-situ tying bench for the sidewall steel bars of the aqueduct; S70, Construction of the sidewall formwork: The sidewall formwork of the aqueduct is constructed by means of a segmented casting formwork system for the sidewall of the aqueduct, with the first-section formwork (33) and the second-section formwork (34) respectively placed on both sides of the first-section sidewall (32) and the second-section sidewall (35), and the steel pipes (36) placed outside all the formworks and fixed by means of tie rods (37). After the construction is completed, concrete is poured and cured; S80, Construction of the external stiffening rib plates of the aqueduct: Formwork is erected at the designated position, with the horizontal support rods (40) fixed to one side outside the sidewall (38) by means of U-shaped fixing parts (39), one end of the hanging rods (41) fixed to the horizontal support rods (40) and the other end fixed to the triangular side formwork (42), the triangular side formwork (42) placed on both sides of the stiffening rib plates (6), the top formwork (43) placed between adjacent triangular side formworks (42), and the U-shaped perforated clamps (44) fixing the two-sided triangular side formworks (42) and the top formwork (43) and tightened by means of rectangular nuts (46) fixing the screw holes (45) of the through screws (47). After completion, concrete is poured and the formwork is removed after the strength reaches the requirement; S90, River restoration: After the construction is completed and inspected and accepted, the equipment and machinery are removed and withdrawn from the site, and the river restoration operation is carried out until the construction is completed.

7. According to the construction method described in claim 6, characterized in that, In step S10, by driving double-row steel sheet piles along the upstream and downstream directions, the river water is diverted into the open channel, and then the water inside the cofferdam is pumped out by means of pumping equipment.

8. According to the construction method described in claim 6, characterized in that, In step S90, a small ramming machine is used to ram and compact the connection between the river dam and the aqueduct. At the same time, soil is filled outside the aqueduct, the steel sheet pile cofferdams on both sides of the river are removed, and the river water flows through the aqueduct to restore the function of the existing river channel.

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