Shield round starting well construction method and matching leveling equipment

Abstract

The application relates to the technical field of shield construction, and discloses a shield round starting shaft construction method and matched leveling equipment, which aims to solve the technical problems that the construction period is long, the engineering construction demand cannot be met, the temporary working shaft occupies a large area, and other construction processes are affected in the prior art. The method comprises the following steps: S1, a round vertical shaft is excavated, a diaphragm wall maintenance structure, a crown beam and an inner lining wall are constructed, and a bottom plate is poured; S2, a shield starting hole door is excavated, a transverse partition wall and a longitudinal partition wall are constructed, the inner lining wall and the diaphragm wall in the shield starting hole door range are removed, and the concrete of the transverse partition wall in the steel ring beam range is removed; S3, a rear pilot hole is excavated, the inner lining wall and the diaphragm wall in the rear pilot hole range are removed; the rear pilot hole is excavated and primary support construction is carried out; and secondary cast-in-place lining in the rear pilot hole is constructed. The application reduces the single shield tunneling distance, shortens the construction period of the whole project, reduces the land occupation area of the temporary working shaft, and does not affect the construction process of other projects.

Description

Technical Field

[0001] This invention relates to the field of tunnel boring machine (TBM) construction technology, and in particular to a method for constructing a circular TBM launching shaft and a matching leveling device. Background Technology

[0002] Intercity railway tunnels are characterized by long distances between adjacent stations (up to 10km), deep tunnels (up to 50m), and large cross-sectional diameters (up to 9m). They are significantly different from subway tunnels, which are typically short (1-2km), shallow (less than 30m), and small (6m) in diameter. The subway shield tunneling method of using stations as launching shafts is no longer applicable to intercity railway tunnels.

[0003] If the intercity railway tunnel only utilizes the station foundation pit as the shield launching and receiving shaft, the required single-heading excavation distance and construction period for a single shield would be excessively long, making it impossible to meet the project's construction needs. Therefore, it is necessary to add temporary working shafts as shield launching shafts within adjacent station sections. This increases the number of shields, reducing the single-heading excavation distance per shield and thus shortening the overall construction period. To minimize the footprint of the temporary working shafts, circular vertical shafts need to be constructed within adjacent station sections as shield launching shafts.

[0004] Chinese patent document 202011249149.5 discloses a method for the separate launching of an ultra-deep circular vertical shaft dual-line shield tunneling machine. During construction, the first shield tunneling machine and the connecting bridge shaft are assembled in the first area; a trolley platform is arranged in the second area; the trolleys are lowered into the shaft and stacked on the trolley platform; reaction frames and supports are installed, completing the launching preparation; the first shield tunneling machine begins excavation; after the first shield tunneling machine has advanced to a point where the trolley for the second shield tunneling machine can be lowered into the shaft, the trolley platform is arranged in the first area; the trolleys are lowered into the shaft and stacked on the trolley platform, completing the launching preparation for the second shield tunneling machine. The method described in this invention, using a trolley stacking arrangement in a limited space, makes full use of the underground space, effectively reducing pipeline extension and avoiding various problems caused by extended pipelines. It has the advantages of simple operation, economy, and high efficiency.

[0005] However, the above-mentioned solutions have at least the following technical problems during implementation: long construction period, unable to meet the needs of project construction, and large land area occupied by temporary working shafts, affecting the construction progress of other projects. Therefore, there is an urgent need to develop a method for constructing a circular shield tunneling launching shaft. Summary of the Invention

[0006] In view of the above technical problems, this disclosure provides a method for constructing a circular shield launching shaft, which solves the technical problems of long construction period in the prior art, which cannot meet the needs of engineering construction, and the large area occupied by temporary working shafts, which affects the construction progress of other projects.

[0007] According to one aspect of this disclosure, a method for constructing a circular shield launching shaft is provided, comprising the following steps:

[0008] S1: Circular shaft excavation. On suburban subway lines with station spacing greater than 5 kilometers, a location less than 3 kilometers from any station along the planned route is selected as the location of the circular starting shaft. At this location, the circular shaft excavation begins by constructing the diaphragm wall support structure from the ground down. After the diaphragm wall is constructed, the capping beam and inner lining wall are constructed sequentially from the ground down using the open-cut method. The inner lining wall is constructed intermittently from top to bottom along the shaft. After the inner lining wall is constructed to the bottom of the shaft, the bottom slab is poured to complete the circular shaft excavation.

[0009] S2: Excavation of the shield tunneling portal. First, construct the transverse and longitudinal partition walls, and pre-embed the steel ring beam of the shield tunneling portal within the transverse partition walls. After the construction of the transverse and longitudinal partition walls is completed, remove the inner lining walls and diaphragm walls within the shield tunneling portal area layer by layer from bottom to top, and fill the space between the diaphragm walls, transverse partition walls, and longitudinal partition walls with concrete in layers. Finally, remove the concrete of the transverse partition walls within the steel ring beam area to complete the excavation of the shield tunneling portal.

[0010] S3: Excavation of the pilot tunnel. First, remove the inner lining wall and diaphragm wall within the pilot tunnel area; then, excavate the pilot tunnel and carry out initial support construction; finally, construct the secondary cast-in-place lining of the pilot tunnel, and then excavate the pilot tunnel.

[0011] The diaphragm wall in S1 consists of a 1.2m thick regular 24-sided polygon.

[0012] The thickness of the inner lining wall in S1 is 1.5m.

[0013] In S1, the inner lining wall is constructed in a ring every 4m from top to bottom along the vertical shaft.

[0014] The thickness of both the transverse and longitudinal partitions in S2 is 1m.

[0015] The concrete in S2 includes plain C20 concrete.

[0016] The removal of the inner lining wall and diaphragm wall within the scope of the rear guide tunnel in S3 includes the following steps: using a water-cooled drill, the inner lining wall and diaphragm wall within the scope of the rear guide tunnel in four parts in sequence: lower right, lower left, upper right, and upper left.

[0017] The step method for excavating the pilot tunnel in S3 includes the following steps: (1) excavating the upper step with a length of 1m; (2) excavating the lower step with a length of 1m; repeating steps (1) and (2) until the excavation of the entire pilot tunnel is completed.

[0018] The initial support construction in S3 includes the following steps: (1) using Φ14mm glass fiber mesh and Φ22mm glass fiber grid arch frame; (2) spraying 25cm thick concrete.

[0019] The secondary cast-in-place lining of the pilot tunnel in S3 includes the following steps: (1) Constructing the bottom slab concrete using the formwork method; (2) Constructing the arch wall and arch top concrete.

[0020] This invention also relates to a leveling device for positioning the transverse partition wall in S2 of the shield tunneling circular launching shaft construction method. The device includes a centering rod, a centering frame for installing the centering rod, and a reference frame for positioning the centering rod. Above the centering rod is a columnar spotlight, and below it is a vertically positioned strip light for detection. Correspondingly, the center of the transverse partition wall has a strip-shaped opening through which the light column of the reference strip or strip light can pass. The reference frame includes two reference plates, the edge shape of which is consistent with the shape and position of the inner lining wall. A positioning strip light is located at the center of each reference plate.

[0021] The centering frame is fitted onto the outer edge of the launching well, and a through hole for installing the centering rod is provided at the center. The centering frame is also provided with a motor and a friction wheel to drive the centering rod to rotate; or the centering frame is rod-shaped, with one end fitted onto the outer edge of the launching well and the other end suspended above the center of the launching well, and at least three through holes for installing the centering rod are provided along the central axis of the centering frame.

[0022] The centering rod comprises at least three assembled rods.

[0023] The beneficial effects of this invention are as follows:

[0024] By adding temporary working shafts and setting up circular vertical shafts as shield launching shafts in adjacent station sections, the number of shields was increased, reducing the tunneling distance of a single shield, thereby shortening the construction period of the entire project. It also reduced the land area occupied by the temporary working shafts, did not affect the construction progress of other projects, and improved construction efficiency. While ensuring construction quality and safety, the project construction plan was reasonable and highly efficient.

[0025] Using diaphragm walls as the foundation pit retaining structure, the horizontal and vertical cross-sectional bearing capacity of the wall is strong, the vertical foundation bearing capacity is strong, the overall stability of the foundation pit retaining structure is high, and it has the advantages of anti-overturning, anti-heave of the pit bottom, and anti-seepage.

[0026] The construction of the cap beam and the continuous reinforced concrete beam connects all the pile foundations together to prevent the top edge of the shaft from collapsing. The reinforced concrete supports the horizontal squeezing force and vertical shear force, and the continuous construction of the inner lining wall ensures the construction quality of the shaft inner lining wall, making its surface smooth and flat.

[0027] The construction of transverse and longitudinal partition walls provides high seismic resistance, flexible layout, and good overall rigidity, especially in the working environment of large spans on suburban lines, further providing safety for construction personnel.

[0028] The leveling device utilizes the relationship between the chord length and the center point of a circle. It is designed to find the accurate center of the circle using two chord lengths. Then, it uses optical path to detect whether the position of the transverse partition wall is accurate. The entire set of equipment is highly adjustable, and the measurement process is accurate and simple, without consuming the physical strength of workers. It is especially suitable for underground correction after ground leveling in long-distance construction. It effectively improves the accuracy of the position of each shield equipment working point in multi-source construction, avoiding inaccuracies in tunnel construction caused by inaccurate transverse partition wall positions. The combination of this equipment and construction methods saves construction time in multi-source construction on the one hand, and the high-precision positioning ensures safe and stable construction on the other hand. Attached Figure Description

[0029] Figure 1 This is a top view of the circular launching shaft structure of the tunnel boring machine;

[0030] Figure 2 This is a side view of the circular launching shaft structure of the tunnel boring machine.

[0031] Figure 3 A schematic diagram showing the demolition sequence of the inner lining wall and diaphragm wall within the pilot tunnel area;

[0032] Figure 4 This is a three-dimensional schematic diagram of the circular launching shaft structure of a tunnel boring machine.

[0033] Figure 5 A schematic diagram of the leveling device during operation;

[0034] Figure 6 for Figure 5 Front view of the structure shown;

[0035] Figure 7 for Figure 6 Sectional view of section AA;

[0036] The components in the diagram are named as follows: 1. Diaphragm wall, 2. Inner lining wall, 3. Transverse partition wall, 4. Longitudinal partition wall, 5. Steel ring beam, 6. Shield launching tunnel, 7. Rear guide tunnel, 8. Base plate, 9. Crown beam, 10. Centering rod, 11. Centering frame, 12. Reference frame, 13. Motor, 14. Friction wheel, 15. Detection strip light, 16. Positioning strip light, 17. Spotlight, 18. Hook mounting slot, 19. Hook. Detailed Implementation

[0037] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Example 1

[0038] This example discloses a method for constructing a circular shield tunneling starting shaft. (See also...) Figures 1 to 7 It includes the following steps:

[0039] S1: Circular shaft excavation. On suburban subway lines with station spacing greater than 5 kilometers, a location less than 3 kilometers from any station along the planned route is selected as the location of the circular starting shaft. At this location, the circular shaft excavation begins by constructing the diaphragm wall support structure from the ground down. After the diaphragm wall is constructed, the capping beam and inner lining wall are constructed sequentially from the ground down using the open-cut method. The inner lining wall is constructed intermittently from top to bottom along the shaft. After the inner lining wall is constructed to the bottom of the shaft, the bottom slab is poured to complete the circular shaft excavation.

[0040] S2: Excavation of the shield tunneling portal. First, construct the transverse and longitudinal partition walls, and pre-embed the steel ring beam of the shield tunneling portal within the transverse partition walls. After the construction of the transverse and longitudinal partition walls is completed, remove the inner lining walls and diaphragm walls within the shield tunneling portal area layer by layer from bottom to top, and fill the space between the diaphragm walls, transverse partition walls, and longitudinal partition walls with concrete in layers. Finally, remove the concrete of the transverse partition walls within the steel ring beam area to complete the excavation of the shield tunneling portal.

[0041] S3: Excavation of the pilot tunnel. First, remove the inner lining wall and diaphragm wall within the pilot tunnel area; then, excavate the pilot tunnel and carry out initial support construction; finally, construct the secondary cast-in-place lining of the pilot tunnel, and then excavate the pilot tunnel after completion.

[0042] In subsequent work, the shield tunneling and tunnel support can be carried out from the shield launching portal in step S2 as the starting point, along the planned path, until the shield tunneling equipment meets the opposite shield equipment.

[0043] The diaphragm wall in S1 consists of a 1.2m thick regular 24-sided polygon.

[0044] The thickness of the inner lining wall in S1 is 1.5m.

[0045] In S1, the inner lining wall is constructed in a ring every 4m from top to bottom along the vertical shaft.

[0046] In S2, the thickness of both the horizontal and vertical partition walls is 1m.

[0047] The concrete in S2 includes plain C20 concrete.

[0048] The removal of the inner lining wall and diaphragm wall within the pilot tunnel area in S3 includes the following steps: using a water-cooled drill, the inner lining wall and diaphragm wall within the pilot tunnel area in the lower right, lower left, upper right, and upper left sections are removed in four parts in sequence.

[0049] The excavation of the pilot tunnel in S3 adopts the step method and includes the following steps: (1) excavate the upper step with a length of 1m; (2) excavate the lower step with a length of 1m; repeat steps (1) and (2) in sequence until the excavation of the entire pilot tunnel is completed.

[0050] The initial support construction in S3 includes the following steps: (1) using Φ14mm glass fiber mesh and Φ22mm glass fiber grid arch frame; (2) spraying 25cm thick concrete.

[0051] The secondary cast-in-place lining of the pilot tunnel in S3 includes the following steps: (1) Constructing the bottom slab concrete using the formwork method; (2) Constructing the arch wall and arch top concrete.

[0052] This embodiment also involves a leveling device, see [link to documentation]. Figures 1 to 7 This is used for positioning the transverse partition wall in S2 of the shield tunneling circular launching shaft construction method. It includes a centering rod 10, a centering frame 11 for installing the centering rod 10, and a reference frame 12 for positioning the centering rod 10. The centering rod 10 is equipped with a columnar spotlight 17 above it and a vertical strip light 15 for detection below it. The center of the transverse partition wall is provided with a strip-shaped cutout through which the reference strip or the light column of the strip light can pass. The reference frame 12 includes two reference plates. The edge shape of the reference plates is consistent with the shape and position of the inner lining wall. The center of the reference plate is provided with a positioning strip light strip 16. During operation, the reference frame 12 is first used to form two chords within a circle by being pressed tightly against the inner lining wall. Then, using the light poles at the center of each chord, the intersection of the two light poles is found; this intersection is the center of the launching shaft. Next, the centering rod 10 is lowered using the center as a reference. After the centering rod 10 is positioned, it is rotated on the ground above the shaft to control the angle of the spotlight 17. During this adjustment, the design angle is found by referring to the design drawings. The angle of the spotlight 17 is consistent with the divergence angle of the bottom detection strip light 15. Afterwards, personnel inside the shaft observe whether the detection strip light 15 and the horizontal partition wall are perpendicular to each other to determine the accuracy of the horizontal partition wall's installation position. When the equipment is not in use and needs to be stored, the reference plate can be hung on the centering frame 11 using hooks 19 for storage.

[0053] The centering frame 11 is fitted onto the outer edge of the launching well, and has a through hole at its center for mounting the centering rod 10. The centering frame 11 also includes a motor 13 for rotating the centering rod 10 and a friction wheel 14. Alternatively, the centering frame 11 can be rod-shaped, with one end fitted onto the outer edge of the launching well and the other end suspended above the center of the launching well. At least three through holes for mounting the centering rod 10 are provided along the central axis of the centering frame 11. The centering frame 11 also includes a motor 13 for rotating the centering rod 10 and a friction wheel 14. In this embodiment, the centering frame 11 can be installed at the center of the launching well based on its diameter, or it can be installed at the corresponding position based on the radius of the launching well. Under the condition of comparing the radius, the flexibility of the equipment is further improved.

[0054] In this embodiment, the centering rod 10 comprises at least three assembled rods. This can accommodate various construction situations at different depths.

[0055] Although some preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0056] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this application and their equivalents, this invention is also intended to include these modifications and variations.

Claims

1. A method of construction of a shield jumbo round starting shaft, characterized in that, It comprises the following steps: S1: circular shaft excavation, in the suburban subway line with a station spacing greater than 5 kilometers, select the planned path along the way, the distance from any station is less than 3 kilometers as the position of the circular starting well point, at the position point, first from the ground down to the diaphragm wall enclosure; After the diaphragm wall is completed, the crown beam and the lining wall are sequentially constructed from the ground down by open excavation method; The lining wall is continuously constructed from top to bottom along the shaft; After the lining wall is constructed to the bottom of the well, the bottom plate is poured to complete the circular shaft excavation; S2: shield starting door excavation, first construct the transverse partition wall and the longitudinal partition wall, the transverse partition wall is pre-buried with the steel ring beam of the shield starting door; After the transverse partition wall and the longitudinal partition wall are constructed, the lining wall and the diaphragm wall within the range of the shield starting door are sequentially removed from bottom to top in layers, and the space between the diaphragm wall, the transverse partition wall and the longitudinal partition wall is filled with concrete in layers; Finally, the concrete of the transverse partition wall within the range of the steel ring beam is removed, and the shield starting door excavation is completed; S3: back lead hole excavation, first remove the lining wall and the diaphragm wall within the range of the back lead hole; Then excavate the back lead hole and construct the primary support; Finally, construct the back lead hole secondary cast-in-place lining, and complete the back lead hole excavation.

2. The method of claim 1, wherein: The diaphragm wall in S1 comprises a 1.2m-thick regular 24-sided polygon, the lining wall in S1 has a thickness of 1.5m, the lining wall in S1 is continuously constructed from top to bottom along the shaft with a width of 4m, and the thickness of the transverse partition wall and the longitudinal partition wall in S2 is 1m.

3. The method of claim 1, wherein: The concrete filled in the space between the diaphragm wall, the transverse partition wall and the longitudinal partition wall in S2 is C20 plain concrete.

4. The method of claim 1, wherein: The removal of the lining wall and the diaphragm wall within the range of the back lead hole in S3 comprises the following steps: the lining wall and the diaphragm wall within the range of the back lead hole are sequentially removed in four parts by using a water mill drill from the right lower part, the left lower part, the right upper part and the left upper part.

5. The method of claim 1, wherein: The step method for excavating the back lead hole in S3 comprises the following steps: (1) excavating an upper step with a length of 1m; (2) excavating a lower step with a length of 1m; sequentially repeating steps (1) and (2) until the entire back lead hole is excavated.

6. The method of claim 1, wherein: The primary support construction in S3 comprises the following steps: (1) using a Φ14mm glass fiber mesh and a Φ22mm glass fiber mesh lattice arch; (2) spraying concrete with a thickness of 25cm.

7. The method of claim 1, wherein: The construction of the back lead hole secondary cast-in-place lining in S3 comprises the following steps: (1) using a mold construction method to first construct the bottom plate concrete; (2) constructing the arch wall and the arch top concrete.

8. A levelling device for positioning the transverse bulkhead in S2 of the method of construction of a shield round start shaft according to claim 1, characterised in that: It comprises a centering rod (10), a centering frame (11) for installing the centering rod (10), and a reference frame (12) for providing positioning for the centering rod (10); the centering rod (10) is provided with a light source columnar spotlight (17) above and a detection strip-shaped light (15) vertically below; a corresponding strip-shaped hollow is provided at the center of the transverse partition wall, through which a reference strip or strip-shaped light column can pass; the reference frame (12) comprises two reference plates, the edge shape of the reference plate is consistent with the shape of the lining wall, and a positioning strip-shaped light belt (16) is provided at the center of the reference plate.

9. The leveling device of claim 8, wherein: The centering frame (11) is clamped on the outer edge of the originating well, and a through hole for installing the centering rod (10) is arranged at the center, and a motor (13) and a friction wheel (14) for driving the centering rod (10) to rotate are further arranged on the centering frame (11); or the centering frame (11) is a rod, one end of which is clamped on the outer edge of the originating well, and the other end is suspended above the center of the originating well, and at least three through holes for installing the centering rod (10) are arranged along the central axis of the centering frame (11).

10. The leveling device of claim 8, wherein: The centering rod (10) comprises at least three assembled rods.

Images