Tunnel center drainage ditch and inverted arch filling integrated construction method

Abstract

The application provides a tunnel center drainage ditch and inverted arch filling integrated construction method, which comprises the following steps: step 1) completing inverted arch lining construction; step 2) installing horse stool supports on the inverted arch lining at least at two positions; step 3) constructing a combination of formwork net and steel bars; step 4) installing the combination on the horse stools at the two positions in step 2); step 5) installing horse stool I for supporting the front section of the tunnel center water ditch pouring formwork; step 6) installing the tunnel center water ditch pouring formwork in the combination; step 7) installing center drainage ditch cover plate steel bars on the two side center water ditch body steel bars; step 8) installing end block formwork; step 9) pouring inverted arch filling concrete; step 10) pouring center drainage ditch concrete; step 11) continuously pouring inverted arch filling concrete; step 12) continuously pouring center drainage ditch concrete; step 13) concrete moisture and temperature preservation and maintenance; step 14) demolding; and step 15) performing circulation construction.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, specifically relating to an integrated construction method for tunnel central drainage ditch and invert arch filling. Background Technology

[0002] To drain seepage water from the surrounding rock and road surface, tunnels typically have central drainage ditches. These ditches are located beneath the road surface, within the concrete indentation of the tunnel arch. Central drainage ditches are mostly reinforced concrete structures with a higher concrete grade than the indentation filling. Generally, the trench is created during the indentation filling process, and the central drainage ditch is constructed subsequently. The utility model patent "Tunnel Central Drainage Ditch Casting Template" (ZL202222780089.0) achieves one-time casting of the central drainage ditch base, body, and cover plate. However, the central drainage ditch construction still lags behind the indentation filling, typically by at least six days. Because the central drainage ditch construction lags behind the indentation filling, the trench in the indentation filling is impassable for vehicles. It is usually covered with steel plates to allow vehicle passage, but this makes the edges of the trench and the contact area with the steel plates prone to crushing. The steel plates are prone to displacement, causing vehicles to fall into the trench and overturn. Deformation of the steel plates can create misalignments, leading to tire blowouts. To address the issues of schedule, safety, and quality in the construction of the central drainage ditch, it is necessary to innovate and develop an integrated construction solution for the central drainage ditch and the invert arch filling. Summary of the Invention

[0003] In order to solve the problems existing in the prior art, the purpose of this invention is to provide an integrated construction method for tunnel central drainage ditch and invert arch filling. This invention has the characteristics of reduced procedures, faster progress, and good integrity of the central drainage ditch.

[0004] The technical solution of this invention is:

[0005] The integrated construction method for tunnel central drainage ditch and invert arch filling provided by this invention includes the following steps:

[0006] Step 1) Complete the invert arch lining construction;

[0007] Step 2) Install trestles at least at two points on the invert arch lining;

[0008] Step 3) Pre-process and install the central drainage ditch reinforcement, and weld the formwork mesh to the outside of the central drainage ditch reinforcement using the reinforcement protective layer; the formwork mesh on both sides is higher than the central drainage ditch reinforcement and the top of the central drainage ditch cover plate; reinforcement protective layer spacers are installed on the bottom inner side and both sides of the central drainage ditch reinforcement; finally, a combination of formwork mesh and reinforcement is formed.

[0009] Step 4) Install the assembly of the non-removable formwork mesh and reinforcing bars described in Step 3) onto the two supports described in Step 2;

[0010] Step 5) Install the support stool I used to support the front section of the formwork for pouring the central water ditch in the tunnel;

[0011] Step 6) Install the formwork for the central drainage ditch in the tunnel into the assembly formed in step 4);

[0012] Step 7) Install the reinforcing steel bars of the central drainage ditch cover plate onto the reinforcing steel bars of the central drainage ditch on both sides according to the design requirements;

[0013] Step 8) Install the stop template;

[0014] Step 9) Pour the invert arch filling concrete;

[0015] Step 10) Pour concrete for the central drainage ditch;

[0016] Step 11) Following step 9) Continue pouring the invert arch filling concrete until the construction requirements are met, and the pouring is complete;

[0017] Step 12) Following step 10), continue pouring the concrete for the central drainage ditch until the construction requirements are met. The pouring is now complete.

[0018] Step 13) Concrete moisture retention and heat preservation curing;

[0019] Step 14) Demolding;

[0020] Step 15) Restart Step 1), and repeat the construction process.

[0021] Furthermore, it also includes: step 16) applying a release agent.

[0022] Furthermore, the trestle consists of a support plate and four legs evenly distributed under the support plate. Each leg is composed of a steel pipe and a scaffold base. One end of the steel pipe is welded to the support plate, and the other end is fitted onto the scaffold base. The height of the trestle is adjusted by the scaffold base.

[0023] Furthermore, the central drainage ditch reinforcement is concave and includes: central ditch body reinforcement on both sides, central ditch bottom reinforcement at the bottom, and central ditch cover plate reinforcement located above the central ditch body reinforcement on both sides.

[0024] Furthermore, reinforcement protective layer spacers should be installed at the lower edge of the central drainage ditch cover plate reinforcement, with a quantity of 4-5 per meter. 2 The reinforcing bars of the central drainage ditch cover and the reinforcing bars of the central drainage ditch on both sides are tied together with iron wire, with a tying point spacing of 0.8m.

[0025] Furthermore, the saddle I and the central drainage ditch are coaxial and installed on the outer edge of the current pouring segment.

[0026] Furthermore, the removable template mesh is composed of multiple corrugated steel plates and multiple V-shaped steel strips evenly spaced.

[0027] Furthermore, step 8) installing the end cap template specifically involves: the front section of the tunnel center ditch pouring template resting on the support I; the end cap template includes a left end cap template and a right end cap template, the left end cap template and the right end cap template are installed on both sides of the support I, and the tunnel center ditch pouring template is clamped tightly so that there is no gap between them.

[0028] The beneficial effects of this invention are:

[0029] This invention involves the one-time forming of the tunnel center drainage ditch base, ditch body, and cover plate, which greatly reduces the number of joints in the center drainage ditch, significantly enhances its overall integrity, and greatly improves construction progress, quality, cost, and safety management.

[0030] This invention involves forming the central drainage ditch and the invert arch filling in one step, thus eliminating the need for pits and steel plates to cover the area behind the invert arch trestle, greatly improving driving safety.

[0031] This invention involves pre-installing a combination of formwork and reinforcing steel for the central drainage ditch in the tunnel, along with a non-removable formwork mesh, within the invert infill and simultaneously pouring the invert infill. This significantly reduces the work cycle and saves costs.

[0032] This invention involves pouring the base, trench body, and cover plate in one go, which reduces the number of steps, speeds up the process, and ensures good overall integrity of the central drainage ditch.

[0033] The present invention utilizes a permanent formwork mesh that is bonded to the concrete. After the concrete is poured, the angular fittings of the mesh automatically embed. This creates a mechanical bond for the next batch of concrete poured, resulting in strong adhesion and shear resistance at the joint. Therefore, the mesh does not need to be removed after concrete pouring.

[0034] The non-removable template mesh of this invention has greater rigidity than thin sheet metal and is less prone to deformation.

[0035] The height of the trestle of the present invention can be adjusted by adjusting the upper and lower screws, making it easy to loosen and remove.

[0036] This invention synchronizes the two processes of filling the original inverted arch and the central water ditch, thus completely solving the problems of progress, safety, and quality in the existing technology.

[0037] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the following describes the preferred embodiments of the present invention in detail with reference to the accompanying drawings. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This is a schematic diagram of the integrated structure of the central drainage ditch and the invert arch filling in the tunnel;

[0040] Figure 2 This is a structural diagram of a combination of removable formwork mesh and reinforcing steel bars;

[0041] Figure 3 This is a schematic diagram of the structure of the horse stool;

[0042] Figure 4 This is a schematic diagram of the head stop template setting;

[0043] Figure 5 This is a structural diagram of the non-removable formwork mesh;

[0044] Figure 6 This is a schematic diagram showing the location of the support stools on the inverted arch lining.

[0045] In the diagram: 1. Central drainage ditch; 2. Removable formwork mesh; 3. Invert arch filling; 4. Formwork for pouring the central drainage ditch in the tunnel; 5. Invert arch lining; 6. Reinforcing steel for the central drainage ditch cover plate; 7. Reinforcing steel for the central drainage ditch body; 8. Reinforcing steel protective layer spacer; 9. Protective layer reinforcing steel; 10. Reinforcing steel for the bottom of the central drainage ditch; 11. Reinforcing bar I; 11-1. Support plate; 11-2. Steel pipe; 11-3. Scaffolding base support; 12. End formwork; 13. Reinforcing bar II; 14. Reinforcing bar III; 15. Misalignment. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Equivalent transformations or substitutions of functions and methods made by those skilled in the art based on these embodiments are all within the protection scope of the present invention.

[0047] Example 1

[0048] The integrated construction method for tunnel central drainage ditch and invert arch filling of the present invention includes the following steps:

[0049] Step 1) Complete the construction of the invert arch lining 5;

[0050] Step 2) Install trestles at least at two locations on the invert arch lining 5;

[0051] Step 3) Pre-process and install the central drainage ditch reinforcement, and weld the no-removal formwork mesh 2 to the outside of the central drainage ditch reinforcement using the reinforcement protective layer 9; the two sides of the no-removal formwork mesh 2 are higher than the central drainage ditch reinforcement and the top of the central drainage ditch cover plate; reinforcement protective layer spacers 8 are installed on the bottom inner side and the inside of both sides of the central drainage ditch reinforcement; finally, a combination of no-removal formwork mesh and reinforcement is formed.

[0052] Step 4) Install the assembly of the non-removable formwork mesh and reinforcing bars described in Step 3) onto the two supports described in Step 2;

[0053] Step 5) Install the support stool I to support the front section of the formwork 4 for pouring the central water ditch in the tunnel;

[0054] Step 6) Install the formwork 4 for the central drainage ditch of the tunnel into the assembly body of Step 4);

[0055] Step 7) Install the central drainage ditch cover steel bar 6 onto the central drainage ditch body steel bar 7 on both sides according to the design requirements;

[0056] Step 8) Install the stop template 12;

[0057] Step 9) Pour the invert arch filler concrete 3;

[0058] Step 10) Pour concrete for the central drainage ditch 1;

[0059] Step 11) Following step 9) Continue pouring the invert arch filling concrete until the construction requirements are met, and the pouring is complete;

[0060] Step 12) Following step 10), continue pouring the concrete for the central drainage ditch until the construction requirements are met. The pouring is now complete.

[0061] Step 13) Concrete moisture retention and heat preservation curing;

[0062] Step 14) Demolding;

[0063] Step 15) Restart Step 1), and repeat the construction process.

[0064] Example 2

[0065] The integrated construction method for tunnel central drainage ditch and invert arch filling of the present invention includes the following steps:

[0066] Step 1) Complete the construction of the invert arch lining 5.

[0067] Furthermore, the inverted arch lining 5 is an arc-shaped pit, which is a concrete or reinforced concrete structure.

[0068] like Figure 1As shown, the invert arch filling 3 and the central drainage ditch 1 involved in this invention are constructed on the invert arch lining 5, wherein the invert arch filling 3 is above the invert arch lining 5, and the central drainage ditch is inside the invert arch filling 3. The elevation and flatness of the invert arch lining 5 should meet the quality requirements to provide conditions for rapid construction of subsequent processes. The structures of the invert arch lining 5, the invert arch filling 3, and the central drainage ditch are all existing technologies.

[0069] Step 2) Install trestles at least at two locations on the invert lining 5.

[0070] Furthermore, such as Figure 3 As shown, the trestle consists of a support plate 11-1 and four legs evenly distributed under the support plate 11-1. Each leg consists of a steel pipe 11-2 and a scaffold base 11-3. One end of the steel pipe 11-2 is welded to the support plate 11-1, and the other end is fitted onto the scaffold base 11-3. The height of the trestle is adjusted by the scaffold base 11-3.

[0071] Furthermore, such as Figure 6 As shown, the two support posts are located at support posts II13 and III14 on the invert lining 5, respectively. Support posts II13 and III14 are positioned along the tunnel face, with support post II13 in front and support post III14 behind. Each support post is located 1 / 4 of the distance from the end of its preceding poured section. Due to the tunnel's length, pouring is carried out in sections, with each pour approximately 5 meters long. This means the center of the support post is approximately 125 cm from the end. This is to reduce the downward deflection of the composite structure of the formwork mesh and reinforcing steel. The position and elevation deviation of the support posts must meet quality requirements.

[0072] Step 3) Pre-process and install the central drainage ditch reinforcement. Weld the no-removal formwork mesh 2 to the outside of the central drainage ditch reinforcement (bottom and two outer sides) using the reinforcement protective layer 9. The two sides of the no-removal formwork mesh 2 are higher than the central drainage ditch reinforcement and the top of the central drainage ditch cover plate. Install the reinforcement protective layer spacers 8 on the bottom inner side and the two sides of the central drainage ditch reinforcement. Finally, a combination of no-removal formwork mesh and reinforcement is formed.

[0073] Furthermore, such as Figure 2 As shown, the central drainage ditch reinforcement is concave and includes: central ditch body reinforcement 7 on both sides, central ditch bottom reinforcement 10 at the bottom, and central ditch cover plate reinforcement 6 located above the central ditch body reinforcement 7 on both sides.

[0074] Furthermore, the number of the steel reinforcement protective layer spacers 8 is 4-5 per m. 2 The steel reinforcement protective layer spacer 8 can be a cement spacer.

[0075] Furthermore, the aforementioned non-removable formwork mesh 2 is a permanent formwork bonded to the concrete. After the concrete is poured, the angular fittings of its mesh automatically embed. This creates a mechanical bond for the next batch of poured concrete, resulting in strong adhesion and shear resistance at the joint. Therefore, it does not need to be removed after the concrete is poured.

[0076] like Figure 5 As shown, the removable formwork mesh 2 is composed of multiple corrugated steel plates and multiple V-shaped steel bars evenly spaced together, providing high rigidity and resistance to deformation. Using the removable formwork mesh 2 achieves the purpose of separating the invert arch filling and the central drainage ditch from concrete of different grades, while also ensuring reliable bonding between the two types of concrete.

[0077] Step 4) Install the combination of the non-removable formwork mesh and steel bars described in Step 3) onto the two supports described in Step 2.

[0078] like Figure 6 As shown, specifically: the assembly of the removable formwork mesh and reinforcing steel is installed on supports II13 and III14. These two supports cannot be removed and are for single use only. Surveyors should verify the elevation and axial position of the removable formwork mesh and reinforcing steel assembly; deviations must meet quality requirements.

[0079] Step 5) Install the saddle I11 used to support the front section of the formwork 4 for pouring the central water ditch in the tunnel.

[0080] The saddle I11 has the same structure as the saddles in the previous two locations. Saddle I11 is coaxial with the central drainage ditch and is installed on the outer edge of the current pouring segment.

[0081] Specifically, during the segmented pouring process, the assumed working condition is that the concrete for the rear set of invert arch filling and the central drainage ditch has been poured, and the concrete for the current set of invert arch lining has been poured. The technical specifications for highway tunnel construction require that the transverse construction joint of the invert arch lining 5 in the current pouring segment be staggered from the transverse construction joint of the rear set of invert arch filling 3 by no less than 50cm. That is, the invert arch lining 5 protrudes 50cm from the rear set of invert arch filling, forming a 50cm misalignment platform 15 at this point. The trestle I is then installed on the misalignment platform 15 (outer edge).

[0082] Step 6) Install the tunnel center ditch pouring template 4 into the assembly in step 4).

[0083] The tunnel center drainage ditch casting template 4 uses template ZL202222780089.0, but differs in that it retains the rear towing wheel of template ZL202222780089.0 while removing the front towing wheel. The front section of the tunnel center drainage ditch casting template 4 is mechanically towed, while the rear section is wheeled. It is pulled out from the rear set of central drainage ditches, passes through the assembly of the non-removable template mesh and reinforcing steel, and rests on the support I at the front, while the rear section remains embedded in the rear set of central drainage ditches for approximately 10cm.

[0084] Step 7) Install the central drainage ditch cover steel bar 6 onto the central drainage ditch body steel bar 7 on both sides according to the design requirements.

[0085] Furthermore, reinforcement protective layer spacers 6 should be installed at the lower edge of the central drainage ditch cover plate reinforcement 6, with a quantity of 4-5 per m. 2 The reinforcing bars 6 of the central drainage ditch cover plate and the reinforcing bars 7 of the two side central drainage ditches are tied together with iron wire at a spacing of 0.8m to prevent the reinforcing bars 6 of the central drainage ditch cover plate from shifting during the concrete pouring process.

[0086] Step 8) Install the stop head template 12.

[0087] like Figure 4 As shown, the front section of the tunnel center drainage ditch casting template 4 rests on the support I. The end-cap template 12 is a fixed steel mold, comprising a left end-cap template and a right end-cap template. The left and right end-cap templates are installed on both sides of the support I, clamping the tunnel center drainage ditch casting template 4 tightly to eliminate gaps between them. The height of the tunnel center drainage ditch casting template 4 is flush with the top surface of the center drainage ditch. The inner edges of the end-cap template 12 and the support I 11 are flush, thus forming a single plane with the invert arch filling 3 and the center drainage ditch 1.

[0088] like Figure 1 As shown, from the outside in, the components are: the non-removable formwork mesh, the reinforcing steel cover, the central drainage ditch reinforcing steel, the reinforcing steel cover spacers, and the central drainage ditch casting formwork, all tightly and securely connected. The rear end of the central drainage ditch casting formwork is embedded in the already poured central drainage ditch, while the front section rests on the support I, held in place by the end formwork on both sides. This combination of the non-removable formwork mesh and reinforcing steel, along with the central drainage ditch casting formwork, forms a stable and robust whole, ensuring that the formwork does not shift during concrete pouring.

[0089] The saddle I and the end formwork here need to be removed after the concrete is poured for the invert arch filling and the central drainage ditch.

[0090] Step 9) Pour the invert arch filling concrete.

[0091] Specifically: Concrete is poured from both sides of the composite structure of the formwork mesh and reinforcing steel bars, with the height difference between the two sides controlled within 20cm to prevent displacement of the composite structure. Pouring is paused when the formwork mesh is submerged 50cm into the concrete to prevent the composite structure from floating.

[0092] Step 10) Pour concrete for the central drainage ditch.

[0093] Concentrated pouring of the bottom, body, and cover plate of the central drainage ditch.

[0094] The specific operation is as follows: the concrete for the central drainage ditch is poured from one side to fill the bottom of the ditch, and then poured from both sides. The concrete at the bottom of the ditch is prone to honeycomb and air bubble defects; this pouring method is to fully vent air and improve the density of the concrete. It should be noted that in existing construction methods, the interval between pouring the invert arch filling concrete and pouring the central drainage ditch bottom and body concrete is at least 3 days, and the interval between pouring the central drainage ditch cover plate and pouring the central drainage ditch bottom and body concrete is also at least 3 days. However, in this invention, the time interval between pouring the invert arch filling concrete and pouring the central drainage ditch concrete is less than 1 hour, essentially making it a single, integrated construction process.

[0095] The concrete pouring height of the central drainage ditch is level with the concrete filling height of the outer arch of the non-removable formwork mesh; pouring is then suspended.

[0096] Step 11) Continue pouring the invert arch filling concrete from step 9) until the construction requirements are met, and the pouring is completed.

[0097] Step 12) Following step 10) Continue pouring the concrete for the central drainage ditch until the construction requirements are met, and the pouring is complete.

[0098] Step 13) Concrete moisture retention and heat preservation curing.

[0099] Step 14) Demolding.

[0100] This includes the removal of the end formwork, the removal of the supporting supports (I), and the demolding of the formwork for the central drainage ditch. Once the invert arch filling strength reaches 2.5 MPa, the end formwork can be removed. Because vehicles will be driving on both the invert arch filling and the central drainage ditch, and the invert arch filling is a solid structure while the central drainage ditch cover is a suspended beam-slab structure, the central drainage ditch cover will become ready for traffic later than the invert arch filling. If traffic were to occur simultaneously with the invert arch filling, the cover would be prone to damage. To ensure the central drainage ditch can be ready for traffic earlier and simultaneously with the invert arch filling, the demolding of the central drainage ditch formwork must be delayed. The central drainage ditch formwork and the central drainage ditch cover form a composite structure, meaning both share the vehicle load.

[0101] Once the strength of the central drainage ditch cover plate meets the requirements for vehicle traffic, the formwork for the central drainage ditch in the tunnel can be demolded, and then the trestles I can be removed.

[0102] Step 15) Restart Step 1), and repeat the construction process.

[0103] Step 16) Apply release agent.

[0104] The application of the release agent is a separate step. This invention uses a long-lasting release agent, applied once every 3-6 sets of tunnel center drainage ditches. The formwork for the tunnel center drainage ditch does not need to be hoisted out of the invert arch foundation pit; it can be temporarily placed on trestles II and III. This significantly reduces the time spent on hoisting machinery and greatly minimizes obstruction to tunnel vehicle passage. The preferred long-lasting release agent is HD-1.

[0105] Compared with the prior art, the present invention,

[0106] (1) Different working conditions. The existing technology is to first pour the invert backfill, leaving a trench in the invert backfill, and then the formwork for the tunnel center ditch is poured in this trench. In this invention, the formwork for the tunnel center ditch, the reinforcing steel, and the non-removable formwork mesh are pre-installed in the invert filling space and poured at the same time as the invert filling.

[0107] (2) Different pouring processes. The existing technology involves pouring the base first, and then pouring the ditch body and cover plate. The present invention pours the base, ditch body and cover plate in one go, which reduces the number of steps, speeds up the process and improves the integrity of the central drainage ditch.

[0108] (3) Different walking methods. Existing technology uses a winch to drag the formwork, while this invention uses mechanical hoisting. Existing technology involves laying the bottom layer of the central drainage ditch first, allowing the formwork to walk and be dragged on the bottom concrete. In this invention, the central drainage ditch is not laid at the bottom, preventing the formwork from walking on the reinforcing mesh. Therefore, the front end is hoisted mechanically, while the rear end is driven by wheels. (ZL202222780089.0 formwork has wheels installed at both the front and rear, using wheeled walking; this invention retains the rear wheels but removes the front wheels.)

[0109] (4) Existing technology only achieves one-time forming of the ditch body and cover plate. It still involves first casting the inverted arch and filling it, and then reserving a groove on the inverted arch. This does not solve the fundamental problem of existing technology. This invention performs the two processes of filling the inverted arch and the central ditch simultaneously, thus completely solving the existing problems of existing technology.

[0110] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail can be made without departing from the spirit and scope of the present invention. Parts and structures not described in detail in this embodiment are common knowledge in the industry and will not be described here.

Claims

1. An integrated construction method for tunnel central drainage ditch and invert arch filling, characterized by: Includes the following steps: Step 1) Complete the invert arch lining construction; Step 2) Install trestles at two points on the invert arch lining; Step 3) Pre-process and install the central drainage ditch reinforcement, and weld the formwork mesh to the outside of the central drainage ditch reinforcement using the reinforcement protective layer; the formwork mesh on both sides is higher than the central drainage ditch reinforcement and the top of the central drainage ditch cover plate; reinforcement protective layer spacers are installed on the bottom inner side and both sides of the central drainage ditch reinforcement; finally, a combination of formwork mesh and reinforcement is formed. The central drainage ditch reinforcement is concave and includes: central ditch body reinforcement on both sides, central ditch bottom reinforcement at the bottom, and central ditch cover plate reinforcement located above the central ditch body reinforcement on both sides; Step 4) Install the assembly of the non-removable formwork mesh and reinforcing bars described in Step 3) onto the two supports described in Step 2; Step 5) Install the support stool I used to support the front section of the formwork for pouring the central water ditch in the tunnel; Step 6) Install the formwork for the central drainage ditch in the tunnel into the assembly formed in step 4); Step 7) Install the reinforcing steel bars of the central drainage ditch cover plate onto the reinforcing steel bars of the central drainage ditch on both sides according to the design requirements; Step 8) Install the stop template; Step 9) Pour the invert arch filling concrete; Step 10) Pour concrete for the central drainage ditch; Step 11) Following step 9) Continue pouring the invert arch filling concrete until the construction requirements are met, and the pouring is complete; Step 12) Following step 10), continue pouring the concrete for the central drainage ditch until the construction requirements are met. The pouring is now complete. Step 13) Concrete moisture retention and heat preservation curing; Step 14) Demolding; Step 15) Restart Step 1), and repeat the construction process.

2. The integrated construction method for tunnel central drainage ditch and invert arch filling according to claim 1, characterized in that: Also includes: Step 16) Apply release agent.

3. The integrated construction method for tunnel central drainage ditch and invert arch filling according to claim 1, characterized in that: The trestle consists of a support plate and four legs evenly distributed under the support plate. Each leg is composed of a steel pipe and a scaffold base. One end of the steel pipe is welded to the support plate, and the other end is fitted onto the scaffold base. The height of the trestle is adjusted by the scaffold base.

4. The integrated construction method for tunnel central drainage ditch and invert arch filling according to claim 1, characterized in that: The lower edge of the reinforcing steel bars of the central drainage ditch cover should be fitted with steel bar protective layer spacers, with a quantity of 4-5 per meter. 2 The reinforcing bars of the central drainage ditch cover and the reinforcing bars of the central drainage ditch on both sides are tied together with iron wire, with a tying point spacing of 0.8m.

5. The integrated construction method for tunnel center drainage ditch and invert arch filling according to claim 1, characterized in that: The trestle I and the central drainage ditch are coaxial and installed on the outer edge of the current pouring segment.

6. The integrated construction method for tunnel central drainage ditch and invert arch filling according to claim 1, characterized in that: The removable formwork mesh is composed of multiple corrugated steel plates and multiple V-shaped steel strips evenly spaced.

7. The integrated construction method for tunnel central drainage ditch and invert arch filling according to claim 1, characterized in that: Step 8) Installing the end cap template specifically involves: the front section of the tunnel center ditch pouring template resting on the support I; the end cap template includes a left end cap template and a right end cap template, the left end cap template and the right end cap template are installed on both sides of the support I, and the tunnel center ditch pouring template is clamped tightly so that there is no gap between them.

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