Local covering and digging structure of subway facility below urban busy road

Abstract

The utility model discloses a local covering and digging structure for subway facilities below urban busy roads. The local covering and digging structure comprises a first-stage structure and a second-stage structure which are constructed by stages. The first-stage first supporting structure is arranged in a first-stage construction area and used for supporting a first-stage foundation pit. The first-stage second supporting structure and the temporary longitudinal supports are located on the inner side of the first-stage first supporting structure. The cover plate is arranged in the first-stage foundation pit, and the first-stage second supporting structure and the temporary longitudinal support support the cover plate. The second-stage construction area covers the end, away from the first-stage second supporting structure, of the cover plate and extends towards one side of the first-stage construction area. The second-stage first supporting structure is arranged in a second-stage construction area and used for supporting a second-stage foundation pit; the second-stage second supporting structure is located on the inner side of the second-stage first supporting structure. The second-stage third supporting structure is arranged above the cover plate and the second-stage second supporting structure; the supporting assembly supports the first-stage second supporting structure and the second-stage second supporting structure. The first-stage structure meets the passing requirement, and the second-stage structure meets the simple and convenient construction requirement.

Description

Technical Field

[0001] The utility model relates to the technical field of subway station construction, in particular to a local cover-and-excavation structure of subway facilities under a busy urban highway. Background Art

[0002] With the continuous development of urban rail transit, the construction of subway stations, especially when the station passes under a busy urban highway, must take into account the need for the urban roads above the station to be put into operation in advance to ensure rapid restoration of traffic. The existing station construction methods mainly include: open excavation, underground excavation and covered excavation.

[0003] The open-cut construction method is reliable and safe, but it has a great impact on existing buildings and traffic around the construction area.

[0004] The dark excavation method is suitable for structures with existing buildings above and very deep buried structures. It has little impact on road traffic during construction, but it has high costs and great construction risks.

[0005] The cover-and-cut method is suitable for areas with loose geological conditions and tunnels above the groundwater level. The cover-and-cut method has a small horizontal displacement of the structure, a high safety factor, and a small impact on the ground. It only blocks ground traffic for a short period of time, and the construction is less affected by the external climate. However, the cover-and-cut method does not allow too many shafts to be left on the cover plate, and the subsequent excavation of earth requires horizontal transportation, which is inconvenient to excavate, has a small construction space, a slow construction speed, a long construction period, and high costs.

[0006] Therefore, it is necessary to study a subway facility structure that can restore busy urban roads to normal use as soon as possible, with simpler construction, safer construction and greater economy. Utility Model Content

[0007] The utility model provides a local cover and excavation structure of subway facilities under a busy urban highway, so as to meet the requirements of restoring the normal use of the busy urban highway as soon as possible, making the construction structure simpler, and making the construction process safer and more economical.

[0008] In order to achieve the above purpose, the technical solution of the utility model is:

[0009] A partial cover-and-excavation structure of a subway facility under a busy urban highway comprises a first-phase structure and a second-phase structure, and the first-phase structure and the second-phase structure are constructed in stages.

[0010] The Phase I structure includes: Phase I enclosure, Phase I foundation pit, Phase I first supporting structure, Phase I second supporting structure, temporary longitudinal supports and cover plates; Phase I enclosure is located on the highway, and Phase I enclosure isolates the Phase I construction area; Phase I first supporting structure is located in the Phase I construction area and is used to support the Phase I foundation pit; Phase I second supporting structure and temporary longitudinal supports are located on the inner side of Phase I first supporting structure, and there are multiple temporary longitudinal supports; the cover plate is located in the Phase I foundation pit, and Phase I second supporting structure and temporary longitudinal supports support the cover plate together.

[0011] The phase II structure includes: phase II enclosure, phase II foundation pit, phase II first support structure, phase II second support structure, phase II third support structure and support components; the phase II enclosure is set on the highway, the phase II enclosure isolates the phase II construction area, the phase II construction area covers the end of the cover plate away from the phase I second support structure and extends to one side of the phase I construction area; the phase II first support structure is set in the phase II construction area and is used to support the phase II foundation pit; the phase II second support structure is located on the inner side of the phase II first support structure and is opposite to the phase I second support structure; the phase II third support structure is set above the cover plate and the phase II second support structure, and the phase II third support structure is used to support the phase II foundation pit; the support components support the phase I second support structure and the phase II second support structure.

[0012] Furthermore, the first supporting structure of the first phase includes a first steel sheet pile and a first temporary support, and the first temporary support is used to support the first steel sheet pile.

[0013] Furthermore, the first-phase second supporting structure adopts an underground continuous wall, and a first plain concrete wall is provided above the first-phase second supporting structure; the temporary longitudinal support is located on the side of the first-phase second supporting structure facing the second-phase second supporting structure.

[0014] Furthermore, a cap beam is constructed on the second supporting structure of the first phase, and a cover plate is constructed between the cap beams.

[0015] Furthermore, the first supporting structure of the second phase includes second steel sheet piles and second temporary supports, and the second temporary supports are used to support the second steel sheet piles.

[0016] Furthermore, the second supporting structure of the second phase adopts an underground continuous wall, and a second plain concrete wall is provided above the second supporting structure of the second phase; the third supporting structure of the second phase includes a first retaining wall and a second retaining wall, the first retaining wall is constructed above the cover plate, and the second retaining wall is constructed above the second supporting structure of the second phase.

[0017] Furthermore, the support assembly includes: a first support, a second support, a third support, a fourth support and a fifth support; the first support is located below the cover plate, and the first support, the second support, the third support, the fourth support and the fifth support are arranged in sequence from top to bottom.

[0018] Furthermore, the support assembly also includes a support replacement.

[0019] Furthermore, a backfill concrete layer is provided under the cover plate, and a second backfill soil layer is provided under the backfill concrete layer.

[0020] Furthermore, the second phase structure also includes temporary supports.

[0021] Beneficial effects:

[0022] The present application discloses a partial cover-and-cut structure for a subway facility under a busy urban highway, which divides the construction of the subway facility into two phases by setting a first-phase structure and a second-phase structure; the first-phase structure is a partial cover-and-cut structure, which is constructed first by the cover-and-cut method, and the second-phase structure is constructed later by the open-cut method; the first-phase structure and the second-phase structure are constructed successively to ensure that only road occupation is required for construction without the need for road closure, and the highway can be quickly restored after the construction of the first-phase structure is completed, meeting the traffic needs of the busy urban highway; the second-phase structure is constructed by the open-cut method, and its construction is simpler, safer and more economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a general schematic diagram of the first-phase structure and the second-phase structure of a partial cover-and-excavation structure of a subway facility under a busy urban highway disclosed by the utility model;

[0025] Figure 2 It is a structural schematic diagram of the first phase structure of a partial cover-and-excavation structure of a subway facility under a busy urban highway disclosed by the utility model;

[0026] Figure 3 This is a schematic diagram of the first phase of the partial cover and excavation structure of a subway facility under a busy urban highway disclosed by the utility model;

[0027] Figure 4 This is a schematic diagram of the second phase of construction of a partial cover and excavation structure of a subway facility under a busy urban highway disclosed in the utility model. Figure 1 ;

[0028] Figure 5 This is a schematic diagram of the second phase of construction of a partial cover and excavation structure of a subway facility under a busy urban highway disclosed in the utility model. Figure 2 ;

[0029] Figure 6The utility model discloses a schematic diagram of the completion of the second phase of a partial cover and excavation structure of a subway facility under a busy urban highway.

[0030] 11. Phase I enclosure; 111. Phase I first enclosure; 112. Phase I second enclosure; 12. Phase I first support structure; 121. First steel sheet pile; 1211. First row of steel sheet piles; 1212. Second row of steel sheet piles; 122. First temporary support; 13. Phase I second support structure; 14. Temporary longitudinal support; 15. Cover plate; 16. First plain concrete wall; 17. Crown beam; 18. First backfill soil layer;

[0031] 21. Phase II enclosure; 211. Phase II first enclosure; 212. Phase II second enclosure; 22. Phase II first support structure; 2211. Third row of steel sheet piles; 222. Second temporary support; 23. Phase II second support structure; 24. Phase II third support structure; 241. First retaining wall; 242. Second retaining wall; 243. Third retaining wall; 25. Second plain concrete wall; 26. Temporary support;

[0032] 31. First support; 32. Second support; 33. Third support; 34. Fourth support; 35. Fifth support; 36. Change support; 4. Backfill concrete layer; 5. Second backfill soil layer;

[0033] 61. Bottom plate; 62. Left wall; 63. Right wall; 64. Top plate; 65. First side wall; 66. Second side wall; 67. Track well top plate;

[0034] 7. The third backfill layer. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0036] A partial cover and excavation structure for subway facilities under a busy urban highway, combined with Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, it includes the first-phase structure and the second-phase structure, which are constructed in phases. The first-phase structure is constructed first and then the second-phase structure. Only road occupation is required for construction without road closure, which can ensure the normal connectivity of the highway network.

[0037] The first phase structure includes: the first phase enclosure 11, the first phase foundation pit, the first phase first support structure 12, the first phase second support structure 13, the temporary longitudinal support 14 and the cover plate 15; the first phase enclosure 11 is set on the highway, and the first phase enclosure 11 isolates the first phase construction area; the first phase first support structure 12 is set in the first phase construction area and used to support the first phase foundation pit; the first phase second support structure 13 and the temporary longitudinal support 14 are located on the inner side of the first phase first support structure 12, and there are multiple temporary longitudinal supports 14; the cover plate 15 is set in the first phase foundation pit, and the first phase second support structure 13 and the temporary longitudinal support 14 support the cover plate 15. By setting the first phase second support structure 13 and the temporary longitudinal support 14 to support the cover plate 15, the cover plate 15 provides support, and the area below the cover plate 15 can be constructed by the cover excavation method. After the completion of the first phase structure, the road surface can be quickly restored to meet the traffic needs of busy urban roads.

[0038] The second phase structure includes: a second phase enclosure 21, a second phase foundation pit, a first second phase support structure 22, a second second phase support structure 23, a third second phase support structure 24 and a support assembly; the second phase enclosure 21 is set on the road, the second phase enclosure 21 isolates the second phase construction area, the second phase construction area covers the cover plate 15 away from the end of the first phase second support structure 13 and extends to one side of the first phase construction area; the second phase first support structure 22 is set in the second phase construction area and is used to support the second phase foundation pit; the second phase second support structure 23 is located inside the second phase first support structure 22 and opposite to the first phase second support structure 13; the second phase third support structure 24 is set above the cover plate 15 and the second phase second support structure 23, and the second phase third support structure 24 is used to support the second phase foundation pit; the support assembly supports the first phase second support structure 13 and the second phase second support structure 23. The second phase first support structure 22 can support the second phase foundation pit and ensure the safe excavation of the second phase foundation pit. The second support structure 23 of the second phase cooperates with the second support structure 13 of the first phase to realize the excavation of the subway facility construction area, and the support assembly supports the second support structure 23 of the second phase and the second support structure 13 of the first phase. The third support structure 24 of the second phase protects the surroundings of the second phase foundation pit. The second phase structure ensures that the second phase construction area can be constructed by open excavation, ensuring the simplicity, safety and economy of construction. In addition, the area below the cover plate 15 is excavated from the second phase construction area by dark excavation, which is convenient for speeding up the construction speed, shortening the construction period, and facilitating the rapid restoration of normal operation of the highway.

[0039] Specifically, the phase one fence 11 includes a phase one first fence 111 and a phase one second fence 112. The phase one first fence 111 stands on one side of the highway, and the phase one second fence 112 stands in the middle of the highway. The phase one construction area is isolated between the phase one first fence 111 and the phase one second fence 112. The phase one construction area can occupy most of the width of the highway, and some lanes are reserved to ensure traffic during the phase one structure construction.

[0040] Preferably, the first support structure 12 of the first phase includes a first steel sheet pile 121 and a first temporary support 122. The first temporary support 122 supports the first steel sheet pile 121, and the first steel sheet pile 121 provides support to ensure the subsequent excavation of the first phase foundation pit.

[0041] Specifically, the first steel sheet piles 121 include a first row of steel sheet piles 1211 and a second row of steel sheet piles 1212 arranged along the width direction of the highway; the first row of steel sheet piles 1211 is far away from the second support structure 23 of the second phase, and the second row of steel sheet piles 1212 is close to the second support structure 23 of the second phase. The first temporary support 122 adopts a steel support, and one end of the first temporary support 122 is fixed on the first row of steel sheet piles 1211, and the other end is fixed on the second row of steel sheet piles 1212.

[0042] Preferably, the first-phase second supporting structure 13 adopts an underground continuous wall, and a first plain concrete wall 16 is arranged above the first-phase second supporting structure 13; the temporary longitudinal support 14 is located on the side of the first-phase second supporting structure 13 facing the second-phase second supporting structure 23. The first-phase second supporting structure 13 supports the cover plate 15 and can also provide lateral protection. The temporary longitudinal support 14 supports the cover plate 15 and can also ensure that the area below the cover plate 15 is connected with the area below the second-phase construction area, which is convenient for excavating the earthwork below the cover plate 15 by dark excavation under the second-phase construction area.

[0043] Specifically, there can be multiple temporary longitudinal supports 14. In this embodiment, two are used as an example. One temporary longitudinal support 14 and the first-phase second supporting structure 13 support the cover plate 15 from both ends, and another temporary longitudinal support 14 supports the cover plate 15 from the middle part to ensure the bearing capacity of the cover plate 15.

[0044] Preferably, a crown beam 17 is constructed on the first-phase second supporting structure 13 , and a cover plate 15 is constructed between the crown beams 17 , so that a reliable connection between the cover plate 15 and the first-phase second supporting structure 13 is achieved through the crown beams 17 .

[0045] Specifically, after the first-phase structure construction is completed, the first-phase foundation pit is backfilled to form a first backfill soil layer 18, and then the road surface is restored.

[0046] Specifically, the phase II enclosure 21 includes a phase II first enclosure 211 and a phase II second enclosure 212. The phase II first enclosure 211 stands on a side of the highway away from the phase I second support structure 13, and the phase II second enclosure 212 is located above the cover plate 15 and is close to the end of the cover plate 15 away from the phase I second support structure 13.

[0047] Preferably, the second-phase first supporting structure 22 includes a second steel sheet pile and a second temporary support 222, and the second temporary support 222 supports the second steel sheet pile. The second steel sheet pile is used for support to ensure the subsequent excavation of the second-phase foundation pit.

[0048] Specifically, the second steel sheet piles include a third row of steel sheet piles 2211, which are opposite to the second row of steel sheet piles 1212. The second row of steel sheet piles 1212 in the first-phase structure is used to support the second-phase foundation pit, saving materials and construction work. The second temporary support 222 also uses steel support, and the second temporary support 222 supports the third row of steel sheet piles 2211 and the second row of steel sheet piles 1212.

[0049] Preferably, the second support structure 23 of the second phase adopts an underground continuous wall, and a second plain concrete wall 25 is arranged above the second support structure 23 of the second phase; the second support structure 23 of the second phase and the second support structure 13 of the first phase work together to support the subsequent excavation. The third support structure 24 of the second phase includes a first retaining wall 241 and a second retaining wall 242, wherein the first retaining wall 241 is constructed above the cover plate 15, and the second retaining wall 242 is constructed above the second support structure 23 of the second phase, and the third support structure 24 of the second phase is used for protection after the excavation of the second phase foundation pit.

[0050] Specifically, the first retaining wall 241 may be directly opposite to the temporary longitudinal support 14 located at the end of the cover plate 15 , so that the force of the first retaining wall 241 is directly transmitted to the temporary longitudinal support 14 through the cover plate 15 .

[0051] Preferably, the support assembly includes: a first support 31, a second support 32, a third support 33, a fourth support 34 and a fifth support 35; the first support 31 is located below the cover plate 15, and the first support 31, the second support 32, the third support 33, the fourth support 34 and the fifth support 35 are arranged in sequence from top to bottom. During subsequent excavation, the first support 31, the second support 32, the third support 33, the fourth support 34 and the fifth support 35 support the second phase second support structure 23 and the first phase second support structure 13.

[0052] Specifically, the first support 31 and the third support 33 are made of concrete, and the second support 32, the fourth support 34 and the fifth support 35 are made of steel. The upper surface of the first support 31 abuts against the lower surface of the cover plate 15, and the first support 31 can support the cover plate 15.

[0053] Specifically, the earthwork is excavated downward from the second phase construction area by open excavation, and then the earthwork in the area below the cover plate 15 is excavated horizontally by dark excavation, and finally the subway facility construction area is obtained. The bottom plate 61, the left side wall 62, the right side wall 63 and the top plate 64 are constructed in the subway facility construction area. A track well is constructed below the second phase construction area, and the track well includes: a first side wall 65, a second side wall 66 and a track well top plate 67. The first side wall 65 is connected to the top plate 64, the second side wall 66 is connected to the right side wall 63, and the track well top plate 67 is arranged on the top of the first side wall 65 and the second side wall 66.

[0054] Preferably, the support assembly further includes a replacement support 36, which is used for temporary support after the fourth support 34 and the fifth support 35 are removed. The two ends of the replacement support 36 are respectively connected to the left wall 62 and the right wall 63, and the replacement support 36 supports the left wall 62 and the right wall 63, so that the left wall 62 supports the first-phase second support structure 13, and the right wall 63 supports the second-phase second support structure 23.

[0055] Preferably, a backfill concrete layer 4 is provided below the cover plate 15, and a second backfill soil layer 5 is provided below the backfill concrete layer 4. When the subway facility construction is completed, backfill is performed above the top plate 64 and between the first-phase second supporting structure 13 and the first side wall 65 to form a second backfill soil layer 5 and a backfill concrete layer 4. The backfill concrete layer 4 and the second backfill soil layer 5 support the cover plate 15 to prevent the cover plate 15 from deforming.

[0056] Specifically, the second phase third support structure 24 also includes a third retaining wall 243, which is constructed above the first side wall 65. The top of the third retaining wall 243 is higher than the cover plate 15. The third retaining wall 243 is used for protection during pouring of the backfill concrete layer 4 to prevent concrete from flowing into the track shaft.

[0057] Preferably, the second phase structure further includes a temporary support 26, one end of the temporary support 26 is connected to the first side wall 65, and the other end is connected to the second side wall 66, and the temporary support 26 temporarily supports the side wall of the rail well. There are multiple temporary supports 26, and two temporary supports 26 are used as an example for illustration.

[0058] Specifically, after the construction of the rail well is completed, the second phase foundation pit is backfilled to form the third backfill soil layer 7, and then the road surface is restored.

[0059] Construction technology of the device in this application:

[0060] Phase I structural construction:

[0061] S11 sets up a first-phase fence 11 on the highway to isolate the first-phase construction area, and relocates the pipelines in this area.

[0062] S12 drills holes in the first phase construction area and constructs the first steel sheet piles 121 of the first phase first supporting structure 12; drills holes in the first phase construction area, first constructs the guide wall and then constructs the underground continuous wall of the first phase second supporting structure 13, and then casts the first plain concrete wall 16 on the top of the underground continuous wall; drills holes in the first phase construction area, hoists the lattice columns into the holes and backfills with dry sand.

[0063] S13 excavates the first phase foundation pit and sets up the first temporary support 122.

[0064] S14: Chisel off the top of the first plain concrete wall 16 and the underground continuous wall of the first-phase second supporting structure 13, construct the cap beam 17 and the cover plate 15, connect the cover plate 15 with the underground continuous wall and the temporary longitudinal support 14, connect one end of the first support 31 to the underground continuous wall, and insert the other end into the soil of the second-phase construction area. Construct the first retaining wall 241 of the second-phase third supporting structure 24.

[0065] S15 After the cover plate 15, the crown beam 17 and the first retaining wall 241 reach the designed strength, the pipelines in this area are relocated, part of the covering soil is backfilled, the first temporary support 122 and the first row of steel sheet piles 1211 are removed, the covering soil is backfilled to the ground, and the road surface is constructed.

[0066] S16 dismantled the first phase enclosure 11 and reopened the highway to traffic.

[0067] Phase II structural construction:

[0068] S21 sets up the second phase fence 21 on the highway to isolate the second phase construction area and relocate the pipelines in this area.

[0069] S22 drills holes in the second phase construction area to construct the third row of steel sheet piles 2211 of the second phase first support structure 22; drills holes in the second phase construction area to first construct a guide wall and then construct an underground continuous wall of the second phase second support structure 23, and then casts on top of the underground continuous wall to form a second plain concrete wall 25.

[0070] S23 excavates the second phase foundation pit and sets up the second temporary support 222 between the third row of steel sheet piles 2211 and the second row of steel sheet piles 1212 .

[0071] S24: excavate the soil, and sequentially set up a first support 31, a second support 32, a third support 33, a fourth support 34 and a fifth support 35 while excavating from top to bottom.

[0072] S25 removes the third row of steel sheet piles 2211, the second row of steel sheet piles 1212 and the second temporary support 222; chisels away the top of the second plain concrete wall 25 and the underground continuous wall of the second phase second supporting structure 23, and constructs a second retaining wall 242 on the top of the underground continuous wall.

[0073] S26 constructs a plain concrete cushion layer, lays a base plate waterproof layer and a waterproof protective layer, constructs the base plate 61 and partially constructs the left side wall 62 and the right side wall 63.

[0074] S27 After the bottom plate 61 and part of the left wall 62 and the right wall 63 reach the designed strength, the fifth support 35 is removed, and the left wall 62 and the right wall 63 are continued to be constructed and the replacement support 36 is erected.

[0075] S28: Remove the fourth support 34, and continue to construct the left wall 62, the right wall 63 and the top plate 64.

[0076] S29: Remove the second support 32 and the third support 33, construct the first side wall 65, the second side wall 66, the ring beam and the retaining plate of the rail well, and after the side wall and the ring beam of the rail well reach the designed strength, lay the waterproof layer and set up the temporary support 26. Construct the third retaining wall 243 on the first side wall 65.

[0077] S30 backfills the soil to 0.5 m below the first support 31 to form a second backfill soil layer 5. C20 concrete is backfilled and compacted from 0.5 m below the first support 31 to the cover plate 15 to form a backfill concrete layer 4.

[0078] S31 removes the temporary support 26 and the replacement support 36, removes the first support 31 in the track well, removes the temporary longitudinal support 14 between the bottom plate 61 and the top plate 64, and then completes the track laying.

[0079] After the S32 track is laid, the track well top plate 67 is cast, and after reaching the designed strength, a waterproof layer is laid; the first retaining wall 241 and the second retaining wall 242 are removed, and the soil is backfilled to form a third backfill soil layer 7 to restore the road surface.

[0080] S33 dismantled the second phase enclosure 21 and reopened the highway to traffic.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the utility model.

Claims

1. A partial cover and excavation structure of a subway facility under a busy urban highway, characterized in that: It includes a first-phase structure and a second-phase structure, and the first-phase structure and the second-phase structure are constructed in stages; The first-phase structure comprises: a first-phase enclosure (11), a first-phase foundation pit, a first-phase first supporting structure (12), a first-phase second supporting structure (13), a temporary longitudinal support (14) and a cover plate (15); The first-phase enclosure (11) is arranged on the highway, and the first-phase enclosure (11) isolates a first-phase construction area; The first phase first support structure (12) is arranged in the first phase construction area and is used for supporting the first phase foundation pit; The first-phase second support structure (13) and the temporary longitudinal support (14) are located inside the first-phase first support structure (12), and the temporary longitudinal support (14) is multiple; The cover plate (15) is arranged in the first-phase foundation pit, and the first-phase second supporting structure (13) and the temporary longitudinal support (14) support the cover plate (15); The second phase structure comprises: a second phase enclosure (21), a second phase foundation pit, a second phase first support structure (22), a second phase second support structure (23), a second phase third support structure (24) and a support assembly; The second-phase enclosure (21) is arranged on the road, and the second-phase enclosure (21) isolates a second-phase construction area, wherein the second-phase construction area covers the end of the cover plate (15) away from the first-phase second supporting structure (13) and extends to one side of the first-phase construction area; The second-phase first supporting structure (22) is arranged in the second-phase construction area and is used for supporting the second-phase foundation pit; The second-phase second supporting structure (23) is located inside the second-phase first supporting structure (22) and is opposite to the first-phase second supporting structure (13); The second-phase third supporting structure (24) is arranged above the cover plate (15) and the second-phase second supporting structure (23), and the second-phase third supporting structure (24) is used for supporting the second-phase foundation pit; The support assembly supports the first-phase second supporting structure (13) and the second-phase second supporting structure (23).

2. The partial cover and excavation structure of a subway facility under a busy urban highway according to claim 1, characterized in that: The first phase first supporting structure (12) comprises a first steel sheet pile (121) and a first temporary support (122), wherein the first temporary support (122) supports the first steel sheet pile (121).

3. The partial cover and excavation structure of a subway facility under a busy urban highway according to claim 1, characterized in that: The first-phase second supporting structure (13) adopts an underground continuous wall, and a first plain concrete wall (16) is arranged above the first-phase second supporting structure (13); the temporary longitudinal support (14) is located on the side of the first-phase second supporting structure (13) facing the second-phase second supporting structure (23).

4. The partial cover and excavation structure of a subway facility under a busy urban highway according to claim 3, characterized in that: A crown beam (17) is applied on the first-phase second supporting structure (13), and the cover plate (15) is applied between the crown beams (17).

5. The partial cover-and-excavation structure of subway facilities under a busy urban highway according to claim 1, characterized in that: The second-phase first supporting structure (22) comprises second steel sheet piles and second temporary supports (222), wherein the second temporary supports (222) support the second steel sheet piles.

6. The partial cover and excavation structure of subway facilities under a busy urban highway according to claim 1, characterized in that: The second-phase second supporting structure (23) adopts an underground continuous wall, and a second plain concrete wall (25) is arranged above the second-phase second supporting structure (23); the second-phase third supporting structure (24) comprises a first retaining wall (241) and a second retaining wall (242), wherein the first retaining wall (241) is constructed above the cover plate (15), and the second retaining wall (242) is constructed above the second-phase second supporting structure (23).

7. The partial cover-and-excavation structure of subway facilities under a busy urban highway according to claim 1, characterized in that: The support assembly comprises: a first support (31), a second support (32), a third support (33), a fourth support (34) and a fifth support (35); the first support (31) is located below the cover plate (15), and the first support (31), the second support (32), the third support (33), the fourth support (34) and the fifth support (35) are arranged in sequence from top to bottom.

8. The partial cover-and-excavation structure of a subway facility under a busy urban highway according to claim 7, characterized in that: The support assembly also includes a support changer (36).

9. The partial cover-and-excavation structure of subway facilities under a busy urban highway according to claim 1, characterized in that: A backfill concrete layer (4) is provided below the cover plate (15), and a second backfill soil layer (5) is provided below the backfill concrete layer (4).

10. The partial cover and excavation structure of subway facilities under a busy urban highway according to claim 1, characterized in that: The second-phase structure also includes temporary support (26).

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