A cast-in-place bottom formwork device and construction method for a tunnel central drainage ditch cover

Abstract

The present invention discloses a cast-in-place bottom formwork device and construction method for a central drainage ditch cover plate in a tunnel, belonging to the technical field of tunnel construction, and comprising: a running device, a bottom formwork device, and a bottom formwork lifting structure; the running device comprises a front section running part, a rear section running part, and a plurality of intermediate section running parts, the front section running part, the plurality of intermediate section running parts, and the rear section running part are pinned in sequence, a pair of the bottom formwork lifting structures are installed on both sides of the top ends of the front section running part, the intermediate section running part, and the rear section running part, and the bottom formwork device is installed on the bottom formwork lifting structure. The steel mold bottom formwork of the present invention is spliced ​​on the front section running part, the plurality of intermediate section running parts, and the rear section running part, and the construction length of the cast-in-place drainage ditch cover plate can be customized, thus avoiding frequent formwork erection and dismantling, improving work efficiency, and saving manpower and material costs.

Description

Technical Field

[0001] The present invention belongs to the technical field of tunnel construction, and in particular relates to a cast-in-place bottom formwork device for a tunnel central drainage ditch cover and a construction method. Background Art

[0002] my country has a vast mountainous area. When building roads in mountainous areas, tunnel construction is necessary. Tunnel construction requires the construction of a central drainage ditch. The existing tunnel central drainage ditch is constructed by first constructing the drainage ditch and then constructing a cover plate on the top of the drainage ditch.

[0003] Traditional tunnel center drainage ditch covers are usually constructed in two ways: prefabricated and cast-in-place.

[0004] This method of prefabricated cover plates has many disadvantages. On-site storage occupies the already narrow space in the tunnel, affecting transportation in the tunnel; prefabricated cover plates are easily damaged by bumps during transportation and installation; prefabricated cover plates require mortar to be placed on the plate base for installation. If the installation is not stable, the cover plates may be damaged or broken when being crushed by heavy vehicles during transportation in the tunnel; after the prefabricated cover plates are installed, the gaps between the plates need to be filled with grouting.

[0005] Therefore, the cast-in-place construction method is often used, and the cast-in-place construction method requires installing a support frame in the drainage ditch and laying bamboo plywood on the support frame; or symmetrically chiseling out 32mm deep notches every 50cm on the plate seats on both sides of the drainage ditch, and laying 20mm diameter steel bars on the crossbeams. The 12mm thick cover plate bottom formwork is laid on the steel bars, and after blocking the gaps on both sides of the bottom formwork, the cover plate steel bars are installed and the cover plate concrete is poured. After the cover plate concrete reaches the required strength, the formwork steel bars and the cover plate bottom formwork in the drainage ditch are removed.

[0006] Both of the above cast-in-place construction methods require setting up formwork in the drainage ditch. After the cover plate is cured, workers need to climb into the narrow drainage ditch to remove the formwork. However, since the construction length of the drainage ditch may be long, and the length of the bottom formwork is fixed, it can only be constructed one section at a time. This requires workers to frequently set up formwork and frequently climb into the drainage ditch. The construction process is time-consuming and labor-intensive, and the construction efficiency is low. Summary of the Invention

[0007] In view of this, the present invention provides a cast-in-place bottom formwork device and construction method for a tunnel central drainage ditch cover, which can customize the construction length of the cast-in-place drainage ditch cover and avoid frequent formwork erection and dismantling.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A cast-in-place bottom formwork device for a tunnel central drainage ditch cover, comprising: a running device, a bottom formwork device and a bottom formwork lifting structure; the running device comprises a front-end section running part, a rear-end section running part and a plurality of intermediate section running parts, the front-end section running part, the plurality of intermediate section running parts and the rear-end section running part are pin-connected in sequence, a pair of the bottom formwork lifting structures are installed on both sides of the top ends of the front-end section running part, the intermediate section running part and the rear-end section running part, and the bottom formwork device is installed on the bottom formwork lifting structure.

[0010] Furthermore, the bottom mold device includes a steel mold bottom mold, an airbag bottom mold and an airbag inflation and deflation structure. The steel mold bottom mold is installed on the bottom mold lifting structure. Longitudinal steel grooves are provided on both sides of the steel mold bottom mold. The airbag bottom mold is embedded in the longitudinal steel grooves, and the airbag inflation and deflation structure is installed between the two longitudinal steel grooves.

[0011] Furthermore, the airbag inflation and deflation structure includes an air supply steel pipe and an air supply rubber hose. The air supply steel pipe is installed between the two longitudinal steel grooves and is connected to the airbag bottom mold. Multiple air supply steel pipes are connected through the air supply rubber hose.

[0012] Furthermore, the bottom mold lifting structure includes a lifting wire rope, a lifting assembly and a rotary roller. The lifting assembly includes a lifting rod, a bolted upper base, a bolted lower base, a wire rope locking part, an upward limiter and a downward limiter. The four lifting rods are hinged in sequence in a diamond shape to generate an upper hinge part, a lower hinge part, a front hinge part and a rear hinge part. The bolted upper base is hinged to the lifting rod at the upper hinge part, and the bolted lower base is hinged to the lifting rod at the lower hinge part. The wire rope locking part is hinged at the bottom hinge part. The front hinge part and the rear hinge part are hinged to the lifting rod, the rotary roller is rotatably installed on the rear end section running part, the lifting wire rope is fixedly installed on the wire rope locking part on one side of the multiple components, and is fixedly installed on the wire rope locking part on the other side of the multiple lifting components after passing around the rotary roller. The rising limiter and the falling limiter are fixedly installed on the lifting wire rope, and the rising limiter and the falling limiter are respectively located on the front and rear sides of each wire rope locking part.

[0013] Furthermore, the bottom mold lifting structure also includes an ascending motor and a descending motor, and the ascending motor and the descending motor are both installed on the front end section running part, one end of the lifting wire rope is fixedly installed on the output end of the ascending motor, and the other end of the lifting wire rope is fixedly installed on the output end of the descending motor.

[0014] Furthermore, the running device also includes a driving device, which includes a winch, a wire rope and a pull rod, one end of the wire rope is fixed on the pull rod, and the other end of the wire rope is fixed on the winch, and the winch is fixedly installed at the front end of the front end section running part.

[0015] A construction method for a cast-in-place bottom formwork device for a tunnel central drainage ditch cover plate comprises the following steps:

[0016] S1. Place the running device in the drainage ditch, pin the front section, middle section, and rear section running parts in sequence, connect the air supply steel pipes on the front section, middle section, and rear section running parts with air supply rubber hoses, and keep the steel mold bottom molds on the front section, middle section, and rear section running parts tightly connected;

[0017] S2. Start the lifting motor and adjust the height of the steel mold bottom mold so that the height of the steel mold bottom mold is flush with the wall of the drainage ditch;

[0018] S3. Pour concrete on the top of the steel formwork bottom formwork and the drainage ditch wall, as well as in the middle of the tunnel structure on both sides, cast the cover plate on site, and maintain the cover plate;

[0019] S4. After the cover plate maintenance is completed, start the lowering motor to separate the steel mold bottom mold from the bottom end of the cover plate, fix the pull rod at the front end of the drainage ditch, and then start the winch. The front section running part, the middle section running part and the rear section running part are pulled along the drainage ditch to the next cover plate construction section.

[0020] Furthermore, in step S1, multiple intermediate section running parts can be pin-connected simultaneously according to the on-site conditions.

[0021] Furthermore, in step S2, after the height of the steel mold bottom mold is adjusted to be flush with the drainage ditch wall, the air supply steel pipe is externally connected to an inflation air compressor to inflate the airbag bottom mold so that the airbag bottom mold is against the drainage ditch wall.

[0022] Furthermore, in step S4, after the cover plate is cured, the air bag bottom mold is deflated through the air supply steel pipe to create a gap between the air bag bottom mold and the drainage ditch wall, and then the descending motor is started to separate the steel mold bottom mold from the bottom end of the cover plate.

[0023] The beneficial effects of the present invention are:

[0024] The present invention's front-end running section, multiple intermediate running sections, and rear-end running section are pin-connected, carrying multiple steel mold bases to the construction location. The base lift mechanism then drives the steel mold bases flush with the drainage ditch wall for cast-in-place construction of the cover slab. The front-end running section, multiple intermediate running sections, and rear-end running section are standard sections of 2-3 meters. During on-site construction, one front section and one rear section are each provided, with the number of intermediate sections added as needed. The construction length can be customized, offering flexibility and facilitating construction. Multiple sections of the cover slab can be cast-in-place simultaneously, eliminating the need for frequent formwork erection and workers having to frequently climb into the drainage ditch to erect and remove the formwork. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0026] Figure 1 The present invention is a structural diagram of a cast-in-place bottom formwork structure of a tunnel center drainage ditch cover during construction in a drainage ditch.

[0027] Figure 2 It is a structural diagram of the cast-in-place bottom formwork structure of the tunnel center drainage ditch cover.

[0028] Figure 3 It is a northeast isometric view of the base mold assembly.

[0029] Figure 4 It is a southwest isometric view of the base mold assembly.

[0030] Figure 5 It is a schematic diagram of the running device structure.

[0031] Figure 6 It is a structural diagram of the bottom mold lifting structure on the walking device.

[0032] Figure 7 It is a structural diagram of the lifting component.

[0033] Figure 8 It is a schematic diagram of the rising state of the lifting component.

[0034] Figure 9 It is a schematic diagram of the descending state of the lifting component.

[0035] Among them, in the figure:

[0036] 100-running device, 110-front section running part, 111-pin, 120-middle section running part, 130-rear section running part, 140-driving device, 141-winch, 142-wire rope, 143-pull rod, 200-bottom mold device, 210-steel mold bottom mold, 211-longitudinal steel trough, 220-airbag bottom mold, 230-airbag inflation and deflation structure, 231-air supply steel pipe, 232-air supply rubber hose, 300-bottom mold lifting structure, 310-lifting wire rope, 320-lifting assembly, 321-lifting rod, 3211-upper hinge, 3212-lower hinge, 3213-front hinge, 3214-rear hinge, 322-bolted upper base, 323-bolted lower base, 324-wire rope locking part, 325-upper limiter, 326-lower limiter, 330-rotating roller, 340-upper motor, 350-lower motor, 400-drainage ditch, 500-cover. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Example 1

[0039] Refer to the attached Figure 1-9 As shown, the present invention provides a cast-in-place bottom formwork device for a tunnel central drainage ditch cover, comprising: a running device 100, a bottom formwork device 200 and a bottom formwork lifting structure 300; the running device 100 comprises a front section running part 110, an intermediate section running part 120 and a rear section running part 130, the front section running part 110, multiple intermediate section running parts 120 and the rear section running part 130 are connected in sequence by pins 111, a pair of bottom formwork lifting structures 300 are installed on both sides of the top of the front section running part 110, the intermediate section running part 120 and the rear section running part 130, and the bottom formwork device 200 is installed on the bottom formwork lifting structure 300. For flexible on-site assembly, the system is divided into three standard 2-3 meter sections: front section 110, middle section 120, and rear section 130. During on-site assembly, one section of each is provided, with the number of middle sections adjusted based on construction needs. This allows for simultaneous cast-in-place construction of multiple sections of the cover 500, eliminating the need for frequent formwork erection and the need for workers to frequently dismantle the formwork by draining the ditch 400.

[0040] The bottom mold device 200 includes a steel mold bottom mold 210, an airbag bottom mold 220 and an airbag inflation and deflation structure 230. The steel mold bottom mold 210 is installed on the bottom mold lifting structure 300. Longitudinal steel grooves 211 are provided on both sides of the steel mold bottom mold 210. The airbag bottom mold 220 is embedded in the longitudinal steel grooves 211, and the airbag inflation and deflation structure 230 is installed between the two longitudinal steel grooves 211.

[0041] The airbag inflation and deflation structure 230 includes a steel air supply pipe 231 and a rubber air supply hose 232. The steel air supply pipe 231 is installed between the two longitudinal steel grooves 211 and communicates with the airbag bottom mold 220. The multiple steel air supply pipes 231 are connected to each other via the rubber air supply hose 232. The airbag inflation and deflation structure 230 is connected to an external air compressor to inflate the airbag bottom molds 220 on both sides of the steel bottom mold 210, forcing the airbag bottom molds 220 to press against the walls of the drainage ditch 400, ensuring a watertight seal between the airbag bottom molds 220 and the walls of the drainage ditch 400.

[0042] The bottom mold lifting structure 300 includes a lifting wire rope 310, a lifting assembly 320 and a rotary roller 330. The lifting assembly 320 includes a lifting rod 321, a bolted upper base 322, a bolted lower base 323, a wire rope locking portion 324, an upward limiter 325 and a downward limiter 326. The four lifting rods 321 are hinged in sequence to form a diamond shape, generating an upper hinge portion 3211, a lower hinge portion 3212, a front hinge portion 3213 and a rear hinge portion 3214. The bolted upper base 322 is hinged to the lifting rod 321 at the upper hinge portion 3211, and the bolted lower base 323 is hinged to the lifting rod 321 at the lower hinge portion 3212. 321 is hinged, the wire rope locking part 324 is hinged to the lifting rod 321 at the front hinge part 3213 and the rear hinge part 3214, the rotary roller 330 is rotatably installed on the rear end section running part 130, the lifting wire rope 310 is fixedly installed on the wire rope locking part 324 on one side of multiple components, and after passing through the rotary roller 330, it is fixedly installed on the wire rope locking part 324 on the other side of multiple lifting components 320, the rising limiter 325 and the falling limiter 326 are fixedly installed on the lifting wire rope 310, and the rising limiter 325 and the falling limiter 326 are respectively located on the front and rear sides of each wire rope locking part 324. Pull the lifting wire rope 310 on the inner side of the lifting assembly 320, and the lifting wire rope 310 pulls the wire rope locking parts 324 on both sides of the lifting assembly 320 to move in opposite directions, so that the four diamond-hinged lifting rods 321 become "tall and thin", and the bolted upper base 322 of the upper hinge part 3211 drives the steel mold bottom mold 210 to rise; the descending motor 350 pulls the lifting wire rope 310 on the outer side of the lifting assembly 320, and the lifting wire rope 310 pulls the wire rope locking parts 324 on both sides of the lifting assembly 320 to move in opposite directions, so that the four diamond-hinged lifting rods 321 become "short and fat", and the bolted upper base 322 of the upper hinge part 3211 drives the steel mold bottom mold 210 to descend. The rising limiter 325 and the falling limiter 326 are respectively located on the front and rear sides of each wire rope locking part 324. The rising limiter 325 and the falling limiter 326 can limit the stroke of the wire rope locking part 324 and the lifting wire rope 310, thereby improving the stability of the lifting assembly 320 during operation and preventing the height of the steel mold bottom mold 210 from being too high or too low.

[0043] The bottom mold lifting structure 300 also includes a lifting motor 340 and a lowering motor 350. Both the lifting motor 340 and the lowering motor 350 are mounted on the front end running section 110. One end of the lifting wire rope 310 is fixedly mounted on the output end of the lifting motor 340, and the other end of the lifting wire rope 310 is fixedly mounted on the output end of the lowering motor 350. The lifting motor 340 pulls the lifting wire rope 310 on the inner side of the two lifting assemblies 320 to achieve the lifting movement of the lifting assemblies 320, thereby driving the steel mold bottom mold 210 to rise. The lowering motor 350 pulls the lifting wire rope 310 on the outer side of the two lifting assemblies 320 to achieve the lowering movement of the lifting assemblies 320, thereby driving the steel mold bottom mold 210 to descend.

[0044] The running device 100 also includes a drive device 140, which includes a winch 141, a wire rope 142, and a pull rod 143. One end of the wire rope 142 is fixed to the pull rod 143, and the other end of the wire rope 142 is fixed to the winch 141. The winch 141 is fixedly mounted on the front end of the front section running part 110. The pull rod 143 is fixed to the unconstructed drainage ditch 400 at the front end, and the winch 141 is turned on and off. One end of the wire rope 142 is fixed to the pull rod 143 and remains in a fixed position. The wire rope 142 is continuously reeled into the winch 141. During this process, because the winch 141 is fixed to the front section running part 110, it drags the front section running part 110, the middle section running part 120, and the rear section running part 130 forward.

[0045] Example 2

[0046] Place the running device 100 at the construction location in the drainage ditch 400, connect the front section running part 110, the middle section running part 120 and the rear section running part 130 with pins 111 in sequence, use the air supply rubber hose 232 to connect the air supply steel pipe 231 on the front section running part 110, the middle section running part 120 and the rear section running part 130, keep the steel mold bottom mold 210 on the front section running part 110, the middle section running part 120 and the rear section running part 130 tightly connected, and according to the on-site conditions, multiple middle section running parts 120 can be connected at the same time using pins 111. The lifting motor 340 is activated, pulling the lifting wire ropes 310 inside the two lifting assemblies 320. The lifting wire ropes 310 pull the wire rope locking parts 324 on both sides of the lifting assemblies 320 in opposite directions, making the four diamond-shaped hinged lifting rods 321 "tall and thin". The upper hinge part 3211 is bolted to the upper base 322 to drive the steel mold bottom mold 210 to rise, adjusting the height of the steel mold bottom mold 210 so that the height of the steel mold bottom mold 210 is flush with the wall of the drainage ditch 400. The airbag inflation and deflation structure 230 is connected to an external air compressor to inflate the airbag bottom molds 220 on both sides of the steel mold bottom mold 210, so that the airbag bottom molds 220 are pressed against the wall of the drainage ditch 400, ensuring that there is no leakage between the airbag bottom mold 220 and the wall of the drainage ditch 400. Concrete is poured between the top of the steel mold base 210 and the drain ditch 400 wall, as well as between the tunnel structures on both sides, to form the cover 500 on site. The cover 500 is then cured. After the cover 500 is cured, the airbag base 220 is deflated through the air supply steel pipe 231, creating a gap between the airbag base 220 and the drain ditch 400 wall. The lowering motor 350 is then activated, pulling the lifting wire ropes 310 on the outside of the lifting assembly 320. The lifting wire ropes 310 pull the wire rope locking parts 324 on both sides of the lifting assembly 320 in opposite directions, making the four diamond-shaped hinged lifting rods 321 "short and fat". The upper base 322 of the bolted upper hinge 3211 drives the steel mold base 210 to descend, and the steel mold base 210 is separated from the bottom end of the cast cover 500. Fix the pull rod 143 on the unconstructed drainage ditch 400 at the front end, control the switch of the winch 141, and fix one end of the wire rope 142 on the pull rod 143 and keep it in place. The wire rope 142 is continuously wound onto the winch 141. During this process, because the winch 141 is fixedly installed on the front section running part 110, it can drag the front section running part 110, the middle section running part 120 and the rear section running part 130 forward to the next cover plate 500 construction section.

[0047] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0048] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A cast-in-place bottom formwork device for a tunnel central drainage ditch cover, characterized in that: include: A running device, a bottom mold device and a bottom mold lifting structure; the running device includes a front section running part, a rear section running part and multiple intermediate section running parts, the front section running part, the multiple intermediate section running parts and the rear section running part are pin-connected in sequence, a pair of the bottom mold lifting structures are installed on both sides of the top ends of the front section running part, the intermediate section running part and the rear section running part, and the bottom mold device is installed on the bottom mold lifting structure; The bottom mold device includes a steel mold bottom mold, an airbag bottom mold and an airbag inflation and deflation structure. The steel mold bottom mold is installed on the bottom mold lifting structure. Longitudinal steel grooves are provided on both sides of the steel mold bottom mold. The airbag bottom mold is embedded in the longitudinal steel grooves. The airbag inflation and deflation structure is installed between the two longitudinal steel grooves. The bottom mold lifting structure includes a lifting wire rope, a lifting assembly and a rotary roller. The lifting assembly includes a lifting rod, a bolted upper base, a bolted lower base, a wire rope locking part, an upward limiter and a downward limiter. The four lifting rods are hinged in sequence in a diamond shape to generate an upper hinge part, a lower hinge part, a front hinge part and a rear hinge part. The bolted upper base is hinged to the lifting rod at the upper hinge part, the bolted lower base is hinged to the lifting rod at the lower hinge part, and the wire rope locking part is hinged to the front hinge part. The hinge part and the rear hinge part are hinged to the lifting rod, the rotary roller is rotatably installed on the rear end section running part, the lifting wire rope is fixedly installed on the wire rope locking part on one side of the multiple components, and is fixedly installed on the wire rope locking part on the other side of the multiple lifting components after passing around the rotary roller. The rising limiter and the falling limiter are fixedly installed on the lifting wire rope, and the rising limiter and the falling limiter are respectively located on the front and rear sides of each wire rope locking part.

2. A cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 1, characterized in that: The airbag inflation and deflation structure includes an air supply steel pipe and an air supply rubber hose. The air supply steel pipe is installed between the two longitudinal steel grooves and is connected to the airbag bottom mold. Multiple air supply steel pipes are connected through the air supply rubber hose.

3. A cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 2, characterized in that: The bottom mold lifting structure also includes an ascending motor and a descending motor, and the ascending motor and the descending motor are both installed on the front end section running part. One end of the lifting wire rope is fixedly installed on the output end of the ascending motor, and the other end of the lifting wire rope is fixedly installed on the output end of the descending motor.

4. A cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 3, characterized in that: The running device also includes a driving device, which includes a winch, a wire rope and a pull rod. One end of the wire rope is fixed to the pull rod, and the other end of the wire rope is fixed to the winch. The winch is fixedly installed at the front end of the front end section running part.

5. A construction method for a cast-in-place bottom formwork device for a tunnel central drainage ditch cover, using the cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 4, characterized in that: The steps include: S1. Place the running device in the drainage ditch, pin the front section, middle section, and rear section running parts in sequence, connect the air supply steel pipes on the front section, middle section, and rear section running parts with air supply rubber hoses, and keep the steel mold bottom molds on the front section, middle section, and rear section running parts tightly connected; S2. Start the lifting motor and adjust the height of the steel mold bottom mold so that the height of the steel mold bottom mold is flush with the wall of the drainage ditch; S3. Pour concrete on the top of the steel formwork bottom formwork and the drainage ditch wall, as well as in the middle of the tunnel structure on both sides, cast the cover plate on site, and maintain the cover plate; S4. After the cover plate maintenance is completed, start the lowering motor to separate the steel mold bottom mold from the bottom end of the cover plate, fix the pull rod at the front end of the drainage ditch, and then start the winch. The front section running part, the middle section running part and the rear section running part are pulled along the drainage ditch to the next cover plate construction section.

6. The construction method of a cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 5, characterized in that: In step S1, according to the on-site conditions, multiple intermediate section running parts can be pin-connected at the same time.

7. The construction method of a cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 5, characterized in that: After the steel mold bottom mold is adjusted to be flush with the drainage ditch wall in step S2, the air supply steel pipe is connected to an air compressor to inflate the airbag bottom mold so that the airbag bottom mold is against the drainage ditch wall.

8. The construction method of a cast-in-place bottom formwork device for a tunnel central drainage ditch cover according to claim 7, characterized in that: In step S4, after the cover plate is cured, the air bag bottom mold is deflated through the air supply steel pipe to create a gap between the air bag bottom mold and the drainage ditch wall, and then the descending motor is started to separate the steel mold bottom mold from the bottom end of the cover plate.

Images