A subway entrance and exit main body and enclosure fully assembled structure and construction method thereof

Abstract

The present invention is a fully assembled structure of a subway entrance and exit body and enclosure and a construction method thereof. The fully assembled structure includes assembled enclosure structures symmetrically arranged on the left and right sides. The top of the assembled enclosure structure on each side is constructed with a crown beam, a retaining wall, and a ditches. The entrance and exit top plate structure and the entrance and exit bottom plate structure are installed from top to bottom between the assembled enclosure structures on the left and right sides; the assembled enclosure structure on each side is assembled from a number of prefabricated ground-connected wall monomers, and the prefabricated ground-connected wall monomers are connected by post-cast joint piles, and two adjacent prefabricated ground-connected wall monomers are provided with a first water stop strip in the connecting seam on both sides of the joint pile. The entrance and exit top plate structure includes an entrance and exit prefabricated top plate and a cast-in-place concrete top plate; the entrance and exit bottom plate structure includes an entrance and exit prefabricated bottom plate and a cast-in-place concrete bottom plate. The subway entrance and exit in the present invention adopts a fully assembled structure, which saves engineering costs, speeds up construction progress, and enhances structural integrity and waterproof performance.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to a subway entrance and exit main body and enclosure fully assembled structure and a construction method thereof. Background Art

[0002] Rail transit construction accounts for a large proportion in urban construction, and research on rail transit assembly technology helps improve construction efficiency and protect urban ecology. At present, rail transit assembly technology is mainly concentrated in the construction of subway stations and interval tunnels. There is still little research on assembled subway entrances and exits, which only involves the assembly of foundation pit retaining structures or the assembly of the main structure of the entrances and exits. There are still few cases where both the retaining structure and the main structure are assembled.

[0003] A Chinese invention patent with announcement number CN115853536B discloses an assembled subway entrance and exit passage structure and component connection nodes. The entrance and exit passage structure includes multiple annular component segments, which include prefabricated components, cast-in-place sealing blocks and waterproof pressure strips. It can shorten the construction period, improve the project quality and reduce the work intensity. However, there are still some shortcomings. The construction method of the foundation pit retaining structure is not comprehensively considered. In soft soil areas, cast-in-place ground-connected walls or construction piles are usually used, with more internal supports, which affects the hoisting operation of the main components, resulting in material waste and extended construction period.

[0004] The Chinese invention patent application with publication number CN115387323A discloses an assembled underground continuous wall connection node and a construction method thereof. The connection nodes are divided into A-type nodes and K-type nodes, which can improve the integrity of the assembled structure, but there are still some shortcomings. The node has poor crack resistance and may affect the waterproof performance of the enclosing structure.

[0005] Therefore, the connection between the subway entrance and exit enclosures and the fully prefabricated nodes of the main structure remains a construction challenge. Summary of the invention

[0006] The present invention aims to solve the connection problem of prefabricated subway entrance and exit nodes, and provides a subway entrance and exit main body and enclosure fully prefabricated structure and a construction method thereof, which can realize the integrated prefabricated construction of the main structure and foundation pit enclosure structure, so that it has good overall waterproof performance and economy.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] A fully assembled structure of a subway entrance and exit body and enclosure, comprising assembled enclosure structures symmetrically arranged on the left and right sides, a crown beam is constructed on the top of the assembled enclosure structure on each side, a retaining wall is constructed on the outside of the top of the crown beam, and a water intercepting ditch is constructed on the outside of the retaining wall, and an entrance and exit top plate structure and an entrance and exit bottom plate structure are installed between the assembled enclosure structures on the left and right sides from top to bottom;

[0009] The assembled enclosure structure on each side is composed of several prefabricated ground-connected wall units assembled in sequence in the horizontal direction. Semicircular grooves running through the middle of the connecting end faces on both sides of the prefabricated ground-connected wall units are provided. Joint piles are cast in the semicircular grooves corresponding to the two adjacent prefabricated ground-connected wall units. The first water stop strips are provided in the connecting seams on both sides of the joint piles of the two adjacent prefabricated ground-connected wall units. Steel corbel steel plates are pre-buried at the bottom of the top plate structure corresponding to the entrance and exit on the side walls of the prefabricated ground-connected wall units, and steel corbels are installed on the side walls of the steel corbel steel plates.

[0010] The entrance and exit top plate structure includes a prefabricated entrance and exit top plate erected on a steel corbel, a second water stop strip is provided between the entrance and exit prefabricated top plate and the assembled enclosure structure, and a cast-in-place concrete top plate is provided on the top of the entrance and exit prefabricated top plate;

[0011] The entrance and exit floor structure includes a prefabricated entrance and exit floor erected on a plain concrete cushion layer, a third water stop is provided between the prefabricated entrance and exit floor and the assembled enclosure structure, and a cast-in-place concrete floor is provided on the top of the prefabricated entrance and exit floor.

[0012] Each prefabricated ground-connected wall unit is symmetrically embedded with wall bottom grouting pipes, and the bottom of the wall bottom grouting pipes passes through the bottom of the prefabricated ground-connected wall unit. A wall side grouting pipe is embedded in the middle of the side wall of each prefabricated ground-connected wall unit. The wall side grouting pipe includes a vertical pipe and a horizontal pipe. The vertical pipe is arranged from the top of the prefabricated ground-connected wall unit to the inside and the length is half of the height of the prefabricated ground-connected wall unit. The horizontal pipe is connected and arranged between the bottom of the vertical pipe and the side of the prefabricated ground-connected wall unit; each prefabricated ground-connected wall unit is provided with an inclinometer tube between the two wall bottom grouting pipes, and an inclinometer device is installed in the inclinometer tube.

[0013] A steel cage is arranged inside the joint pile, and the steel cage includes a number of joint pile main bars evenly distributed around the circumference, and spiral stirrups are welded around the outer periphery of the joint pile main bars.

[0014] A first pre-embedded anchor steel bar and a first steel bar connector are pre-embedded at the cast-in-place concrete top plate on the side wall of the prefabricated ground-connected wall unit, and a second pre-embedded anchor steel bar and a second steel bar connector are pre-embedded at the cast-in-place concrete bottom plate on the side wall of the prefabricated ground-connected wall unit.

[0015] A steel support plate and an upper pull connector are pre-buried between the entrance and exit top plate structure and the entrance and exit bottom plate structure on the side wall of the prefabricated ground-connected wall unit, and the upper pull connector is located above the steel support plate.

[0016] Support pads are provided between the steel corbels and the prefabricated top plates of the entrances and exits.

[0017] The first stirrups are embedded in the top of the prefabricated top plate of the entrance and exit, the first main bars are welded between the first stirrups in the same row, the first stirrups and the first main bars are arranged in the cast-in-place concrete top plate, and the first main bars are connected to the first embedded anchor bars through the first steel bar connector.

[0018] Second stirrups are embedded in the top of the prefabricated floor slab of the entrance and exit, second main bars are welded between the second stirrups in the same row, the second stirrups and second main bars are arranged in the cast-in-place concrete floor slab, and the second main bars are connected to the second embedded anchor bars through the second steel bar connector.

[0019] The above-mentioned construction method of a subway entrance and exit main body and enclosure fully assembled structure comprises the following specific steps:

[0020] S1. Site hardening. Prefabricated enclosure structures are assembled with prefabricated ground-connected wall units. The concrete seepage resistance grade of prefabricated ground-connected wall units is not less than P8. The prefabricated size error of a single prefabricated ground-connected wall unit is less than 5mm, and the installation error of embedded parts is less than 1mm. The prefabricated ground-connected wall units are excavated into trenches using underwater trenching machines, and mud wall protection is used. The prefabricated ground-connected wall units are transported to the construction site in advance, and are hoisted and inserted into the prefabricated ground-connected wall units in sequence using lifting equipment. After that, the steel cage is hoisted, and after the bottom is cleared, the joint piles are poured underwater. The concrete of the joint piles uses self-compacting concrete with a seepage resistance grade of not less than P8. In order to reduce the settlement of the prefabricated ground-connected wall units, two wall bottom grouting pipes are used for wall bottom grouting. The lower end of the wall bottom grouting pipe extends 0.3m from the bottom of the prefabricated ground-connected wall unit. Grouting is stopped when the grouting volume meets the design requirements. After the wall bottom grouting is completed, the wall side grouting is carried out. Then the construction of the crown beam, retaining wall, precipitation well, and intercepting ditch is carried out.

[0021] S2. The water level starts to drop to 1m below the excavation surface of the foundation pit the day before the excavation. Water is dropped as needed, and the water level changes are monitored at any time. Emergency plans are prepared to prevent accidents. The foundation pit is excavated to 600mm below the first support, and the first support is erected between the two crown beams.

[0022] S3. Excavate the foundation pit to 600mm below the second support, set up the second support between the assembled enclosure structures on both sides, connect the second support to the prefabricated ground wall monomer through steel support steel plates and upper pull connectors, and use upper pull and lower support to ensure that the second support is firmly connected;

[0023] S4. Excavate the foundation pit to the designed pit bottom elevation, construct plain concrete cushion layer, waterproof layer and its protective layer to reduce the exposure time of the foundation pit;

[0024] S5. The prefabricated entrance and exit floor plate is hoisted on the plain concrete cushion layer, and the third water stop strip is set between the prefabricated entrance and exit floor plate and the prefabricated ground-connected wall unit. The second main reinforcement is connected to the second embedded anchor reinforcement through the second reinforcement connector, and the cast-in-place concrete floor plate is cast. The concrete of the cast-in-place concrete floor plate adopts self-compacting concrete with a water resistance grade not lower than P8. After the cast-in-place concrete floor plate reaches the required strength, the second support is removed;

[0025] S6. Weld steel brackets on steel bracket steel plates, place support pads, hoist the prefabricated top plate of the entrance and exit, set a second water stop strip between the prefabricated top plate of the entrance and exit and the prefabricated ground-connected wall unit, connect the first main reinforcement with the first embedded anchor reinforcement through the first reinforcement connector, cast the cast-in-place concrete top plate, and use self-compacting concrete with a water resistance grade not lower than P8 for the cast-in-place concrete top plate. After the cast-in-place concrete top plate reaches the required strength, remove the first support;

[0026] S7. A waterproof layer and a protective layer are laid on the top of the prefabricated roof of the entrance and exit. After the protective layer reaches a certain strength, backfill with soil. After backfilling is completed, stop precipitation.

[0027] The beneficial effects of the present invention are as follows: the subway entrance and exit of the present invention adopts a fully assembled structure, which saves engineering costs and speeds up the construction progress; the prefabricated ground-connected wall units are connected in the form of post-cast joint piles; the external waterproofing of the structure adopts a variety of waterproofing forms such as water stop strips and self-compacting concrete, thereby enhancing the structural integrity and waterproof performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the subway entrance and exit main body and enclosure fully assembled structure in the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the prefabricated ground-connected wall unit in the present invention;

[0030] Figure 3 A schematic diagram of connecting two adjacent prefabricated ground-connected wall units in the present invention;

[0031] Figure 4 It is a schematic diagram of the connection between the prefabricated ground-connected wall unit and the entrance and exit top plate structure and the entrance and exit bottom plate structure in the present invention;

[0032] Figure 5 It is a schematic diagram of the prefabricated top plate of the entrance and exit in the present invention;

[0033] In the figure: 1-prefabricated enclosure structure; 2-cap beam; 3-retaining wall; 4-intercepting ditch; 5-entrance top plate structure; 6-entrance bottom plate structure; 7-plain concrete cushion layer; 8-support pad; 9-first support; 10-second support;

[0034] 11-prefabricated ground-connected wall unit; 12-semicircular groove; 13-joint pile; 14-first water stop strip; 15-steel corbel steel plate; 16-steel corbel; 17-grouting pipe at the bottom of the wall; 18-grouting pipe at the side of the wall; 19-inclinometer pipe; 110-first embedded anchor steel bar; 111-first steel bar connector; 112-second embedded anchor steel bar; 113-second steel bar connector; 114-steel support steel plate; 115-upper pull connector;

[0035] 51-prefabricated top plate of entrance and exit; 52-second water stop strip; 53-cast-in-place concrete top plate;

[0036] 61-prefabricated entrance and exit floor plate; 62-third water stop strip; 63-cast-in-place concrete floor plate;

[0037] 131-joint pile main reinforcement; 132-spiral stirrups;

[0038] 511-first stirrup; 512-first main reinforcement;

[0039] 611-second stirrup; 612-second main reinforcement;

[0040] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0041] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description. It should be noted that the accompanying drawings are all in a very simplified form and are not in precise proportions, and are only used to facilitate and clearly assist in explaining the purpose of the embodiments of the present invention.

[0042] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a component centered. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a component centered. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a component centered. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0044] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0045] A subway entrance and exit main body and enclosure fully assembled structure, such as Figure 1 As shown, it includes assembled enclosure structures 1 symmetrically arranged on left and right sides, a cap beam 2 is constructed on the top of the assembled enclosure structure 1 on each side, a retaining wall 3 is constructed on the outer side of the top of the cap beam 2, a drainage ditch 4 is constructed on the outer side of the retaining wall 3, and an entrance and exit top plate structure 5 and an entrance and exit bottom plate structure 6 are installed between the assembled enclosure structures 1 on the left and right sides from top to bottom.

[0046] The assembled enclosure structure 1 on each side is composed of a number of prefabricated ground-connected wall units 11 assembled in sequence in the horizontal direction. Figure 2 As shown, semicircular grooves 12 running through the upper and lower parts are provided at the middle positions of the connecting end faces on both sides of the prefabricated ground-connected wall monomer 11, and wall bottom grouting pipes 17 are symmetrically embedded in each prefabricated ground-connected wall monomer 11, and the bottom of the wall bottom grouting pipes 17 passes through the bottom of the prefabricated ground-connected wall monomer 11, and a wall side grouting pipe 18 is embedded in the middle position of the side wall of each prefabricated ground-connected wall monomer 11, and the wall side grouting pipe 18 includes a vertical pipe and a horizontal pipe, the vertical pipe is arranged from the top of the prefabricated ground-connected wall monomer 11 to the inside and the length is half of the height of the prefabricated ground-connected wall monomer 11, and the horizontal pipe is connected and arranged between the bottom of the vertical pipe and the side of the prefabricated ground-connected wall monomer 11, and each prefabricated ground-connected wall monomer 11 is provided with an inclinometer tube 19 between the two wall bottom grouting pipes 17, and an inclinometer device is installed in the inclinometer tube 19.

[0047] A joint pile 13 is cast in the semicircular groove 12 corresponding to two adjacent prefabricated ground wall units 11. Figure 3 As shown, two adjacent prefabricated ground-connected wall units 11 are provided with a first water stop strip 14 in the connecting seam on both sides of the joint pile 13, and a steel cage is provided inside the joint pile 13. The steel cage includes a plurality of joint pile main bars 131 evenly distributed around the circumference, and spiral stirrups 132 are welded to the periphery of the joint pile main bars 131.

[0048] A steel corbel steel plate 15 is pre-buried on the side wall of the prefabricated ground-connected wall unit 11 corresponding to the bottom of the entrance and exit top plate structure 5, and a steel corbel 16 is installed on the side wall of the steel corbel steel plate 15;

[0049] The entrance and exit top plate structure 5 is as follows Figure 4As shown, it includes a prefabricated entrance and exit top plate 51 erected on the steel corbel 16 , a second water stop strip 52 is provided between the prefabricated entrance and exit top plate 51 and the assembled enclosure structure 1 , and a cast-in-place concrete top plate 53 is provided on the top of the prefabricated entrance and exit top plate 51 .

[0050] Entrance and exit floor structure 6 Figure 4 As shown, it includes a prefabricated entrance and exit floor plate 61 erected on a plain concrete cushion layer 7, a third water stop strip 62 is provided between the prefabricated entrance and exit floor plate 61 and the assembled enclosure structure 1, and a cast-in-place concrete floor plate 63 is provided on the top of the prefabricated entrance and exit floor plate 61.

[0051] like Figure 4 As shown, a first embedded anchor steel bar 110 and a first steel bar connector 111 are embedded in the side wall of the prefabricated ground-connected wall unit 11 corresponding to the cast-in-place concrete top plate 53, and a second embedded anchor steel bar 112 and a second steel bar connector 113 are embedded in the side wall of the prefabricated ground-connected wall unit 11 corresponding to the cast-in-place concrete bottom plate 63.

[0052] like Figure 4 As shown, a steel support plate 114 and an upper pull connector 115 are pre-buried between the entrance and exit top plate structure 5 and the entrance and exit bottom plate structure 6 on the side wall of the prefabricated ground-connected wall unit 11 , and the upper pull connector 115 is located above the steel support plate 114 .

[0053] like Figure 4 As shown, a support pad 8 is provided between the steel corbel 16 and the prefabricated top plate 51 of the entrance and exit.

[0054] like Figure 4 , Figure 5 As shown, a first stirrup 511 is embedded in the top of the prefabricated entrance and exit top plate 51, and first main bars 512 are welded between the first stirrups 511 in the same row. The first stirrups 511 and the first main bars 512 are arranged in the cast-in-place concrete top plate 53, and the first main bars 512 are connected to the first embedded anchor bars 110 through the first steel bar connector 111.

[0055] like Figure 4 As shown, second stirrups 611 are embedded in the top of the prefabricated entrance and exit floor plate 61, and second main bars 612 are welded between the second stirrups 611 in the same row. The second stirrups 611 and the second main bars 612 are arranged in the cast-in-place concrete floor plate 63, and the second main bars 612 are connected to the second embedded anchor bars 112 through the second steel bar connector 113.

[0056] like Figure 5 As shown, a plurality of reinforcing ribs are embedded in the prefabricated top plate 51 of the entrance and exit and in the prefabricated bottom plate 61 of the entrance and exit.

[0057] The above-mentioned construction method of a subway entrance and exit main body and enclosure fully assembled structure comprises the following specific steps:

[0058] S1. Site hardening. The prefabricated enclosure structure 1 is assembled with prefabricated ground-connected wall units 11. The concrete impermeability grade of the prefabricated ground-connected wall units 11 is not less than P8. The prefabricated size error of a single prefabricated ground-connected wall unit 11 is less than 5mm, and the installation error of embedded parts is less than 1mm. The prefabricated ground-connected wall units 11 are excavated into trenches using underwater trenching machines, and mud wall protection is used. The prefabricated ground-connected wall units 11 are transported to the construction site in advance, and are hoisted and inserted into the prefabricated ground-connected wall units 11 in sequence using hoisting equipment. Then the steel is hoisted. After the reinforcement cage is cleaned, the joint pile 13 is poured underwater. The concrete of the joint pile 13 adopts self-compacting concrete with a water resistance grade not lower than P8; in order to reduce the settlement of the prefabricated ground-connected wall monomer 11, the wall bottom grouting is carried out through two wall bottom grouting pipes 17. The lower end of the wall bottom grouting pipe 17 extends 0.3m from the bottom of the prefabricated ground-connected wall monomer 11. The grouting is stopped after the grouting volume meets the design requirements; after the wall bottom grouting is completed, the wall side grouting is carried out; then the construction of the crown beam 2, the retaining wall 3, the precipitation well, and the intercepting ditch 4 is carried out;

[0059] Wall side grouting process: connect the grouting equipment to the wall side grouting pipe 18 to ensure a firm connection and good sealing; during grouting, strictly control the grouting pressure and flow rate, observe changes in the surrounding environment, and prevent slurry overflow and leakage; after grouting is completed, the orifice of the wall side grouting pipe 18 should be sealed to prevent subsequent construction from causing damage to the wall side grouting pipe 18 or slurry leakage;

[0060] S2. Start to reduce water level 15 days before the excavation of the foundation pit, and reduce it to 1m below the excavation surface of the foundation pit. Reduce water level as needed, pay attention to water level changes at any time, strengthen monitoring, make emergency plans, and prevent accidents. Excavate the foundation pit to 600mm below the first support 9, and set up the first support 9 between the two crown beams 2;

[0061] S3. The foundation pit is excavated to 600 mm below the second support 10, and the second support 10 is set up between the assembled enclosure structures 1 on both sides. The second support 10 is connected to the prefabricated ground-connected wall monomer 11 through the steel support steel plate 114 and the upper pull connector 115. The upper pull and lower support are used to ensure that the second support 10 is firmly connected;

[0062] S4. Excavate the foundation pit to the designed pit bottom elevation, construct plain concrete cushion layer 7, waterproof layer and its protective layer to reduce the exposure time of the foundation pit;

[0063] S5. The entrance and exit prefabricated bottom plate 61 is hoisted on the plain concrete cushion layer 7. The third water stop strip 62 is arranged between the entrance and exit prefabricated bottom plate 61 and the prefabricated ground wall unit 11. The second main reinforcement 612 is connected to the second embedded anchor reinforcement 112 through the second reinforcement connector 113. The cast-in-place concrete bottom plate 63 is cast. The concrete of the cast-in-place concrete bottom plate 63 adopts self-compacting concrete with an impermeability grade not lower than P8. After the cast-in-place concrete bottom plate 63 reaches the required strength, the second support 10 is removed.

[0064] S6, welding the steel corbel 16 on the steel corbel steel plate 15, placing the support pad 8, hoisting the prefabricated top plate 51 of the entrance and exit, setting the second water stop strip 52 between the prefabricated top plate 51 of the entrance and exit and the prefabricated ground connecting wall unit 11, connecting the first main reinforcement 512 with the first embedded anchor reinforcement 110 through the first reinforcement connector 111, pouring the cast-in-place concrete top plate 53, the cast-in-place concrete top plate 53 adopts self-compacting concrete with an impermeability grade not lower than P8, and removing the first support 9 after the cast-in-place concrete top plate 53 reaches the required strength;

[0065] S7. A waterproof layer and a protective layer are laid on the top of the prefabricated top plate 51 of the entrance and exit, and after the protective layer reaches a certain strength, the soil is backfilled. After the backfilling is completed, precipitation is stopped.

[0066] The subway entrance and exit in the present invention adopts a fully assembled structure, which saves engineering costs and speeds up the construction progress. The prefabricated ground-connected wall units 11 are connected in the form of post-cast joint piles 13, and the external waterproofing of the structure adopts various waterproofing forms such as water stop strips and self-compacting concrete, which enhances the structural integrity and waterproof performance.

[0067] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A fully assembled structure of a subway entrance and exit body and enclosure, characterized in that: It comprises assembled enclosure structures (1) symmetrically arranged on the left and right sides, a crown beam (2) is constructed on the top of the assembled enclosure structure (1) on each side, a retaining wall (3) is constructed on the outer side of the top of the crown beam (2), and a drainage ditch (4) is constructed on the outer side of the retaining wall (3), and an entrance and exit top plate structure (5) and an entrance and exit bottom plate structure (6) are installed from top to bottom between the assembled enclosure structures (1) on the left and right sides; The assembled enclosure structure (1) on each side is formed by assembling a plurality of prefabricated ground-connected wall units (11) in sequence in the horizontal direction. Semicircular grooves (12) penetrating from top to bottom are provided at the middle positions of the connecting end faces on both sides of the prefabricated ground-connected wall units (11). Joint piles (13) are cast in the semicircular grooves (12) corresponding to the two adjacent prefabricated ground-connected wall units (11). First water stop strips (14) are provided in the connecting seams on both sides of the joint piles (13) of the two adjacent prefabricated ground-connected wall units (11). A steel corbel steel plate (15) is pre-buried at the bottom of the entrance and exit top plate structure (5) on the side wall of the prefabricated ground-connected wall unit (11), and a steel corbel (16) is installed on the side wall of the steel corbel steel plate (15); The entrance and exit top plate structure (5) comprises an entrance and exit prefabricated top plate (51) mounted on a steel bracket (16), a second water stop strip (52) is provided between the entrance and exit prefabricated top plate (51) and the assembled enclosure structure (1), and a cast-in-place concrete top plate (53) is provided on the top of the entrance and exit prefabricated top plate (51); The entrance and exit floor structure (6) comprises an entrance and exit prefabricated floor (61) erected on a plain concrete cushion layer (7), a third water stop strip (62) is provided between the entrance and exit prefabricated floor (61) and the assembled enclosure structure (1), and a cast-in-place concrete floor (63) is provided on the top of the entrance and exit prefabricated floor (61); A first pre-embedded anchoring steel bar (110) and a first steel bar connector (111) are pre-embedded at a location corresponding to the cast-in-place concrete top plate (53) on the side wall of the prefabricated ground-connected wall unit (11), and a second pre-embedded anchoring steel bar (112) and a second steel bar connector (113) are pre-embedded at a location corresponding to the cast-in-place concrete bottom plate (63) on the side wall of the prefabricated ground-connected wall unit (11); A first stirrup (511) is pre-buried at the top of the entrance / exit prefabricated top plate (51), first main bars (512) are welded between the first stirrups (511) in the same row, the first stirrups (511) and the first main bars (512) are arranged in the cast-in-place concrete top plate (53), and the first main bars (512) are connected to the first pre-buried anchoring bars (110) via a first steel bar connector (111); A second stirrup (611) is pre-buried on the top of the entrance / exit prefabricated bottom plate (61), second main bars (612) are welded between the second stirrups (611) in the same row, the second stirrups (611) and the second main bars (612) are arranged in the cast-in-place concrete bottom plate (63), and the second main bars (612) are connected to the second pre-buried anchor bars (112) via a second steel bar connector (113).

2. A subway entrance and exit main body and enclosure fully assembled structure according to claim 1, characterized in that: Each prefabricated ground-connected wall unit (11) is pre-embedded with a wall bottom grouting pipe (17) symmetrically on the left and right. The bottom of the wall bottom grouting pipe (17) passes through the bottom of the prefabricated ground-connected wall unit (11). A wall side grouting pipe (18) is pre-embedded in the middle of the side wall of each prefabricated ground-connected wall unit (11). The wall side grouting pipe (18) comprises a vertical pipe and a horizontal pipe. The vertical pipe is arranged from the top of the prefabricated ground-connected wall unit (11) to the inside and has a length of half the height of the prefabricated ground-connected wall unit (11). The horizontal pipe is arranged between the bottom of the vertical pipe and the side of the prefabricated ground-connected wall unit (11). Each prefabricated ground-connected wall unit (11) is provided with an inclinometer pipe (19) between the two wall bottom grouting pipes (17). An inclinometer device is installed in the inclinometer pipe (19).

3. A subway entrance and exit main body and enclosure fully assembled structure according to claim 2, characterized in that: A steel cage is provided inside the joint pile (13), the steel cage comprising a plurality of joint pile main bars (131) evenly distributed around the circumference, and spiral stirrups (132) are welded around the outer periphery of the joint pile main bars (131).

4. A subway entrance and exit main body and enclosure fully assembled structure according to claim 3, characterized in that: A steel support plate (114) and an upper pull connector (115) are pre-buried between the entrance and exit top plate structure (5) and the entrance and exit bottom plate structure (6) on the side wall of the prefabricated ground-connected wall unit (11), and the upper pull connector (115) is located above the steel support plate (114).

5. A subway entrance and exit main body and enclosure fully assembled structure according to claim 4, characterized in that: A support pad (8) is provided between the steel bracket (16) and the prefabricated top plate (51) of the entrance and exit.

6. A subway entrance and exit main body and enclosure fully assembled structure according to claim 5, characterized in that: A plurality of reinforcing ribs are pre-buried inside the prefabricated entrance and exit top plate (51) and the prefabricated entrance and exit bottom plate (61).

7. A construction method for the subway entrance and exit main body and enclosure fully assembled structure as claimed in claim 6, characterized in that: The specific steps are: S1. Site hardening. The prefabricated enclosure structure (1) is assembled with prefabricated ground-connected wall units (11). The concrete impermeability grade of the prefabricated ground-connected wall units (11) is not less than P8. The prefabricated dimension error of a single prefabricated ground-connected wall unit (11) is less than 5 mm, and the installation error of embedded parts is less than 1 mm. The prefabricated ground-connected wall units (11) are excavated into trenches using an underwater trenching machine, and mud wall protection is used. The prefabricated ground-connected wall units (11) are transported to the construction site in advance, and are hoisted and inserted into the prefabricated ground-connected wall units (11) in sequence using hoisting equipment. Then, the steel cage is hoisted. After the bottom is cleaned, the joint piles (13) are poured underwater. The concrete of the joint piles (13) is self-compacting concrete with a water resistance grade not lower than P8. In order to reduce the settlement of the prefabricated ground-connected wall monomer (11), the wall bottom is grouting through two wall bottom grouting pipes (17). The lower end of the wall bottom grouting pipe (17) extends 0.3m from the bottom of the prefabricated ground-connected wall monomer (11). The grouting is stopped after the grouting volume meets the design requirements. After the wall bottom grouting is completed, the wall side grouting is carried out. Then, the crown beam (2), retaining wall (3), precipitation well, and intercepting ditch (4) are constructed. S2. Start to reduce water level 15 days before the excavation of the foundation pit, and reduce it to 1m below the excavation surface of the foundation pit. Reduce water level as needed, pay attention to water level changes at any time, strengthen monitoring, and prepare emergency plans to prevent accidents. Excavate the foundation pit to 600mm below the first support (9), and erect the first support (9) between the two crown beams (2); S3. The foundation pit is excavated to 600 mm below the second support (10), and the second support (10) is erected between the assembled enclosure structures (1) on both sides. The second support (10) is connected to the prefabricated ground-connected wall unit (11) through a steel support steel plate (114) and an upper pull connector (115). An upper pull and lower support are used to ensure that the second support (10) is firmly connected; S4. Excavate the foundation pit to the designed pit bottom elevation, construct a plain concrete cushion layer (7), a waterproof layer and its protective layer to reduce the exposure time of the foundation pit; S5, hoisting the entrance and exit prefabricated bottom plate (61) on the plain concrete cushion layer (7), arranging a third water stop strip (62) between the entrance and exit prefabricated bottom plate (61) and the prefabricated ground-connected wall unit (11), connecting the second main reinforcement (612) to the second embedded anchor reinforcement (112) via a second reinforcement connector (113), pouring the cast-in-place concrete bottom plate (63), using self-compacting concrete with a water resistance grade not less than P8 for the concrete of the cast-in-place concrete bottom plate (63), and removing the second support (10) after the cast-in-place concrete bottom plate (63) reaches a certain strength; S6, welding a steel bracket (16) on the steel bracket steel plate (15), placing a support pad (8), hoisting the prefabricated top plate (51) of the entrance and exit, setting a second water stop strip (52) between the prefabricated top plate (51) of the entrance and exit and the prefabricated ground-connected wall unit (11), connecting the first main reinforcement (512) to the first embedded anchor reinforcement (110) through the first reinforcement connector (111), pouring the cast-in-place concrete top plate (53), using self-compacting concrete with a water resistance grade not less than P8 for the cast-in-place concrete top plate (53), and removing the first support (9) after the cast-in-place concrete top plate (53) reaches the required strength; S7. A waterproof layer and a protective layer are laid on the top of the prefabricated top plate (51) of the entrance and exit. After the protective layer reaches a certain strength, backfill with soil. After backfilling is completed, precipitation is stopped.

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