Subway underground excavation station top-lifting channel double-layer primary support arch structure and construction method
By adopting a double-layer initial arch structure in the top-top-mounted channel of the subway concealed excavation station, the problem of difficult to control the excavation height and width during the construction of the top-top-top-mounted channel is solved, the construction risk and cost are reduced, and the construction is safe and efficient. and environmentally friendly.
Patent Information
- Application Number
- CN202411752052.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-02-18
AI Technical Summary
During the concealed excavation construction of subway stations, it is difficult to accurately control the excavation height and width of the ceiling-mounted passage construction, resulting in safety risks such as collapse of the tunnel and leakage of groundwater. In addition, traditional methods cause the top height to exceed the design elevation, increasing construction costs and construction cycles .
The double-layer initial arch structure of the top-top passage of the subway station is adopted, including the arch frame layer and the main steel frame layer set in a tight row. Through the combination of the gantry steel frame, the main steel frame, the cross beam and the oblique steel plate, the more Large cross-sectional dimensions and stronger load-bearing capacity reduces the amount of arch replacement construction and over-excavation backfill.
Through the double-layer initial support arch structure, the risks and costs of the top-lift channel construction are reduced, the safety and construction period of the construction are ensured, and the high-quality and fast controllable state of the construction process is achieved.
Smart Images
Figure CN119466890A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of tunnel construction, and relates to a double-layer primary support arch structure of a cantilevered passage of a subway dark-excavated station and a construction method. Background Art
[0002] With the acceleration of urbanization, subways are an important means to alleviate urban traffic pressure, and their construction scale and speed are constantly increasing. In the subway network planning of major cities, subway stations are key nodes connecting lines, and the choice of construction method is crucial. Especially in the central area of the city, due to the complex surface environment, dense buildings, and busy traffic, the traditional open-cut method is often not applicable due to the large impact on ground traffic and the large amount of demolition. Therefore, dark excavation technology has become the preferred method for urban subway station construction with its advantages of small impact on the ground and flexible construction.
[0003] Concealed excavation stations usually enter the main area of the station through pre-set auxiliary passages for construction, and this process has extremely high technical requirements. Especially when facing large underground space structures such as subway stations, how to safely and efficiently achieve the conversion from the auxiliary passage to the main body of the station is a major challenge in construction. The construction of the elevated top channel is a key step in this conversion process. It requires precise control of the excavation height and width without destroying the stability of the original stratum structure to ensure the smooth progress of subsequent construction.
[0004] However, the top conversion process is not easy, especially in areas with complex geological conditions, such as soft soil, aquifers or rock formations. Improper selection of construction methods can easily lead to safety risks such as tunnel top collapse and groundwater leakage, which not only affects the construction progress, but also may endanger the safety of construction workers. Therefore, a scientific and reasonable construction plan is particularly important.
[0005] The traditional method of top-lifting channel construction often results in the top height exceeding the design elevation of the main station tunnel, forming unnecessary space. This not only increases the construction cost, but also prolongs the construction period because a large amount of plain concrete needs to be used for backfilling to eliminate the gap. In addition, over-excavation may also lead to increased disturbance of the stratum and increase the risk of stratum instability. During the backfilling process, how to ensure the density and uniformity of the backfill material to avoid the formation of voids or uneven settlement is also one of the difficulties in controlling the construction technology.
[0006] In view of the above-mentioned problems, the industry needs to explore innovative construction technologies and, through technological innovation, realize the refinement and intelligence of the construction of elevated ceiling passages in underground excavation stations, ensure the safety, efficiency and environmental protection of subway station construction, and provide more solid technical support for the development and utilization of urban underground space. Summary of the invention
[0007] In view of this, the purpose of the present invention is to provide a double-layer primary support arch structure and construction method for a subway underground excavation station cantilever passage, which fully utilizes the primary support structure of the passage, reduces arch replacement construction, reduces over-excavation and backfilling, ensures the safety of the cantilever passage and the construction period, and makes the construction process high-quality, fast and controllable.
[0008] In order to achieve the above object, the present invention provides the following technical solutions:
[0009] A double-layer primary arch structure of a cantilevered passage in a subway underground station comprises a plurality of arch frame layers closely arranged in the cantilevered passage along the length direction of the cantilevered passage, a main steel frame layer is arranged between the arch frame layer and the cantilevered passage, the main steel frame layer is fixed on the arch frame layer, and forms a double-layer primary arch structure; the main steel frame layer comprises a portal steel frame, a main steel frame and a cross beam which are sequentially connected from top to bottom, the portal steel frame comprises two first columns arranged opposite to each other, the cross beam is arranged between adjacent first columns, and the cross beam is fixed to the arch frame layer through a second column; the main steel frame is fixed to the cross beam through an oblique steel plate, and the portal steel frame is fixedly connected to the main steel frame.
[0010] Optionally, the inclined steel plate (26) includes a horizontal plane and an inclined plane that are intersectingly arranged, the horizontal plane is arranged on the crossbeam (23), and the inclined plane is in contact with one end of the main steel frame (22).
[0011] Optionally, the portal steel frame and the crossbeam are arranged along the width direction of the cantilevered channel, and the main steel frame and the second column are arranged in sequence in a plurality along the width direction of the cantilevered channel; each of the main steel frames (22) is arranged at an angle, and the lower end is fixedly connected to the oblique steel plate (26).
[0012] Optionally, the first column and / or the second column is a vertical steel frame.
[0013] Optionally, a single-layer steel mesh is hung on one side of the portal steel frame close to the main steel frame, and C25 early-strength concrete is sprayed on the steel mesh.
[0014] Optionally, locking foot anchor rod groups are respectively provided at both ends and the middle of the portal steel frame, and at the middle and the bottom of the first column.
[0015] Optionally, each of the locking foot anchor rod groups includes two locking foot anchor rods inserted into the inner wall of the tunnel at different angles.
[0016] Optionally, the locking foot anchor rod group arranged in the middle of the first column is located on the tunnel step dividing line.
[0017] Optionally, the arch frame layer includes at least 3 arch frames which are closely spaced radially along the cantilevered passage, with a close spacing of 1.2m to 1.5m.
[0018] A construction method for a double-layer primary arch structure of a subway station cantilevered passage using any of the above-mentioned methods comprises the following steps:
[0019] S1, carry out the top construction, excavate from the auxiliary channel to the interface of the main tunnel, and after the excavation is completed, set up three arch frames closely at the starting position of the top portal frame section, weld steel plates on the top of the three arch frames, and then embed the main steel frame between the steel plate and the top of the excavated tunnel, and place it on the inclined steel plate on the top of the steel frame, and fill it with concrete to make it dense, and perform initial support;
[0020] S2, construct the upper steps of the main tunnel, set up several portal steel frames in sequence according to the changes of the excavation contour line, and connect the portal steel frames with steel bars; the top excavation contour line is raised from the auxiliary channel at an angle of 15° to the arch top of the main tunnel;
[0021] S3: After the portal steel frame in the cantilever channel is installed, anchor spraying support is carried out, and the initial anchor support is carried out together with the main tunnel;
[0022] S4, after the overall construction of the cantilevered passage is completed, the sprayed concrete on the inner side of the portal steel frame is removed;
[0023] S5, the main steel frame layer of the main tunnel is constructed. The main steel frame layer is supported on three closely spaced steel frames and welded to the portal steel frame through oblique steel plates. At the same time, a locking anchor group is installed on the portal steel frame, a steel mesh is hung, and C25 early-strength concrete is sprayed on the steel mesh;
[0024] S6. After the deformation, support, settlement and safety monitoring data are stable, the portal steel frame columns are cut out in sequence according to the main tunnel excavation sequence, the top arch layer of the main tunnel and shotcrete are constructed, and the top arch layer of the main tunnel is firmly connected with the main steel frame layer.
[0025] The beneficial effects of the present invention are:
[0026] The present invention is applicable to tunnel construction that utilizes an auxiliary channel to enter a dark-excavated large-section tunnel for process conversion. In the construction of a dark-excavated large-section subway station top channel, by optimizing the excavation process of the construction channel entering the station main tunnel top channel, a double-layer primary support arch is adopted, that is, a portal steel frame + main steel frame support, which has a larger cross-sectional size and stronger bearing capacity, fully utilizes the channel primary support structure, reduces arch replacement construction, reduces over-excavation and backfilling, ensures the safety of the station top channel and the construction period, and makes the construction process in a high-quality, fast and controllable state, and has certain promotion value. The excavation of the present invention adopts a non-explosive excavation method, uses a breaker for excavation operations, reduces the impact of construction on the surrounding environment, and has the characteristics of high safety, low noise, and less pollution.
[0027] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:
[0029] Figure 1 It is a schematic diagram of a double-layer primary support structure;
[0030] Figure 2 for Figure 1 Side view of the structure of the main steel frame layer;
[0031] Figure 3 This is a schematic diagram of a portal steel frame;
[0032] Figure 4 It is a flow chart of construction steps.
[0033] Figure numerals: 1 arch frame layer, 2 main steel frame layer, 21 portal steel frame, 22 main steel frame, 23 crossbeam, 24 first column, 25 second column, 26 oblique steel plate, 27 locking foot anchor rod group, 28 steel mesh. DETAILED DESCRIPTION
[0034] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.
[0035] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.
[0036] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.
[0037] See also Figure 1 to Figure 4 The invention is a double-layer primary arch structure of a cantilevered passage of a subway underground excavation station, comprising a plurality of arch frames 1 arranged closely in the cantilevered passage along the length direction of the cantilevered passage, a main steel frame layer 2 arranged between the arch frame layer 1 and the cantilevered passage, and the main steel frame layer 2 fixed on the arch frame layer 1 to form a double-layer primary arch structure; the main steel frame layer 2 comprises a portal steel frame 21, a main steel frame 22 and a cross beam 23 connected in sequence from top to bottom, the portal steel frame 21 comprises two first columns 24 arranged oppositely, the cross beam 23 is arranged between adjacent first columns 24, and the cross beam 23 is fixed on the arch frame layer 1 through a second column 25; the main steel frame 22 is fixed on the cross beam 23 through an oblique steel plate 26, and the portal steel frame 21 is fixedly connected to the main steel frame 22. The portal steel frame 21 layer and the main arch frame layer 1 form a double-layer primary arch structure to reduce the arch replacement construction and the amount of over-excavation and backfilling.
[0038] The inclined steel plate 26 includes a horizontal surface and an inclined surface that are intersecting with each other. The horizontal surface is arranged on the crossbeam 23 , and the inclined surface is in contact with one end of the main steel frame 22 .
[0039] The portal steel frame 21 and the cross beam 23 are arranged along the width direction of the cantilevered passage, and the main steel frame 22 and the second column 25 are arranged in sequence in a number along the width direction of the cantilevered passage; each of the main steel frames 22 is arranged at an angle, and the lower end is fixedly connected to the oblique steel plate 26. A single-layer steel mesh 28 is hung on the side of the portal steel frame 21 close to the main steel frame 22, and C25 early-strength concrete is sprayed on the steel mesh 28. Locking foot anchor rod groups 27 are respectively arranged at both ends and the middle of the portal steel frame 21, and in the middle and bottom of the first column 24. Each locking foot anchor rod group 27 includes two locking foot anchor rods inserted into the inner wall of the tunnel at different angles. The locking foot anchor rod group 27 arranged in the middle of the first column 24 is located on the tunnel step dividing line.
[0040] The first column 24 and / or the second column 25 are vertical steel frames. An adjustable support device is provided at the bottom of the column to adapt to the foundation conditions under different geological conditions.
[0041] The arch frame layer 1 includes at least 3 arch frames which are closely spaced along the radial direction of the cantilevered passage, with a close spacing of 1.2m to 1.5m, so as to enhance the structural stability.
[0042] The double-layer primary support arch structure of the present invention is suitable for dark-excavated large-section tunnel projects with complex geological conditions and high requirements for the impact on the surrounding environment, and can significantly reduce construction risks and improve construction efficiency.
[0043] The construction method of the double-layer primary support arch structure of the subway underground excavation station cantilevered passage using any of the above methods comprises the following steps:
[0044] S1, first carry out construction preparations such as the layout of air and water pipes, power facilities, and ventilation facilities, and then carry out top construction, excavate from the auxiliary channel to the interface position of the main tunnel, use a modified 485 short-arm breaker during excavation, and after excavation, set up three arch frames closely at the starting position of the top portal section, weld steel plates on the top of the three arch frames, and then embed the main steel frame 22 between the steel plate and the top of the excavated tunnel, and place it on the oblique steel plate 26 on the top of the steel frame, and use concrete to fill and compact it, and perform initial support;
[0045] S2, construct the upper steps of the main tunnel, and set up a number of portal steel frames 21 in sequence according to the change of the excavation contour line. The portal steel frames 21 are connected by steel bars; the top excavation contour line is raised from the auxiliary channel at an angle of 15° to the arch top of the main tunnel;
[0046] After the portal steel frame 21 is erected, the first layer of initial support is promptly applied. The spacing between the portal steel frames 21 of the main tunnel of the cantilevered channel is 0.75m, and the top excavation contour line is raised from the top of the auxiliary channel at an angle of 15° to the designed station main arch position. The setting height of several portal steel frames 21 arranged in sequence along the length direction of the cantilevered channel matches the height of the cantilevered channel and changes with the change of the height of the cantilevered channel. Then, according to the outer contour line of the excavation of the main arch of the station, it is set up 320mm outside, and the rectangular passage within the section range of the station is excavated in sections according to the step method. During the construction process, it is necessary to erect a portal steel frame 21 according to the height change. The portal steel frame 21 is assembled according to the construction situation. The portal frame is pre-assembled for overall installation, and then the portal frame is fixed at a specific position and connected with steel bars. The portal frame is installed in steps. First, the columns are fixed, and then the upper components are installed in turn. After the assembly is completed, the adjacent portal frames are connected with steel bars. Φ22 steel bars are used to connect the two I-beams on the arch top with a circumferential spacing of 1m. The I-beams are welded to the connecting steel plates, and the connecting steel plates are connected with M20 bolts.
[0047] S3, after the portal steel frame 21 in the cantilever channel is installed, anchor spraying support is carried out, and the initial anchor support is carried out together with the main tunnel, including the use of hollow grouting anchors for support;
[0048] S4, after the overall construction of the cantilevered passage is completed, the SY155 breaker hammer is used to break the sprayed concrete on the inner side of the portal steel frame 21.
[0049] S5, construct the main steel frame layer 2 of the main tunnel, support the main steel frame layer 2 on three closely spaced steel frames and weld it firmly to the portal steel frame 21 through the inclined steel plate 26, and at the same time, apply the locking foot anchor rod group 27 on the portal steel frame 21, hang the steel mesh 28, and use the wet spraying manipulator to spray C25 early-strength concrete on the steel mesh 28 to ensure the stability of the steel frame.
[0050] S6, after the deformation, support, settlement and safety monitoring data are stable, according to the main tunnel excavation sequence, the portal steel frame 21 columns are cut off in sequence, the main tunnel top arch layer and shotcrete are constructed, and the main tunnel top arch layer is firmly connected with the main steel frame layer 2.
[0051] The construction method of the present invention is particularly suitable for dark-digging large-section tunnel projects with complex geological conditions and high requirements on the construction environment. Systematic safety measures and environmental protection measures are taken during the construction process, including setting up warning signs, strengthening monitoring and measurement, and reasonably arranging construction time to reduce noise and dust pollution.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.
Claims
1. A double-layer primary arch structure for a cantilevered passage in a subway underground excavation station, characterized in that: The invention comprises a plurality of arch frame layers (1) which are closely arranged in the longitudinal direction of the cantilevered passage, a main steel frame layer (2) is arranged between the arch frame layer (1) and the cantilevered passage, the main steel frame layer (2) is fixed on the arch frame layer (1), and a double-layer primary support arch structure is formed; the main steel frame layer (2) comprises a portal steel frame (21), a main steel frame (22) and a cross beam (23) which are connected and arranged in sequence from top to bottom, the portal steel frame (21) comprises two first columns (24) which are arranged opposite to each other, the cross beam (23) is arranged between adjacent first columns (24), and the cross beam (23) is fixed on the arch frame layer (1) through a second column (25); the main steel frame (22) is fixed on the cross beam (23) through an oblique steel plate (26), and the portal steel frame (21) is fixedly connected to the main steel frame (22).
2. The double-layer primary arch structure of the cantilevered passage of a subway underground excavation station according to claim 1 is characterized in that: The inclined steel plate (26) comprises a horizontal surface and an inclined surface which are arranged to intersect each other, the horizontal surface is arranged on the crossbeam (23), and the inclined surface is fitted with one end of the main steel frame (22).
3. The double-layer primary arch structure of the cantilevered passage of a subway underground excavation station according to claim 1 is characterized in that: The portal steel frame (21) and the cross beam (23) are arranged along the width direction of the cantilevered passage, and a plurality of the main steel frames (22) and the second columns (25) are arranged in sequence along the width direction of the cantilevered passage; each of the main steel frames (22) is arranged obliquely, and the lower end is fixedly connected to the oblique steel plate (26).
4. The double-layer primary arch structure of the cantilevered passage of a subway station according to claim 3 is characterized by: The first column (24) and / or the second column (25) are vertical steel frames.
5. The double-layer primary arch structure of the cantilevered passage of a subway underground excavation station according to claim 1 is characterized by: A single-layer steel mesh (28) is hung on one side of the portal steel frame (21) close to the main steel frame (22), and C25 early-strength concrete is sprayed on the steel mesh (28).
6. The double-layer primary arch structure of the cantilevered passage of a subway underground station according to claim 1 is characterized in that: Foot locking anchor rod groups (27) are respectively provided at both ends and the middle of the portal steel frame (21), and at the middle and the bottom of the first upright column (24).
7. The double-layer primary arch structure of the cantilevered passage of a subway station according to claim 6 is characterized by: Each of the locking foot anchor rod groups (27) comprises two locking foot anchor rods inserted into the inner wall of the tunnel at different angles.
8. The double-layer primary arch structure of the cantilevered passage of a subway station as claimed in claim 6 is characterized by: The foot locking anchor rod group (27) arranged in the middle of the first column (24) is located on the tunnel step boundary line.
9. The double-layer primary arch structure of the cantilevered passage of a subway underground excavation station according to claim 1 is characterized by: The arch frame layer (1) comprises at least three arch frames which are closely spaced radially along the cantilevered passage, with a close spacing of 1.2m to 1.5m.
10. A construction method using the double-layer primary arch structure of a subway underground excavation station cantilevered passage according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, carry out the top construction, excavate from the auxiliary channel to the interface position of the main tunnel, and after the excavation is completed, three arch frames are closely arranged at the starting position of the top portal frame section, and steel plates are welded on the upper parts of the three arch frames. Then, the main steel frame (22) is embedded between the steel plate and the top of the excavated tunnel and rests on the oblique steel plate (26) on the upper part of the steel frame, and concrete is used to fill and compact it to provide initial support; S2, constructing the upper step of the main tunnel, erecting a number of portal steel frames (21) in sequence according to the change of the excavation contour line, and connecting the portal steel frames (21) by steel bars; the top excavation contour line is raised from the auxiliary channel at an inclination angle of 15° to the arch top position of the main tunnel; S3, after the portal steel frame (21) in the cantilever channel is installed, anchor spraying support is carried out, and initial anchor support is carried out together with the main tunnel; S4, after the overall construction of the cantilevered passage is completed, the inner side of the portal steel frame (21) is sprayed with concrete; S5, constructing the main steel frame layer (2) of the main tunnel, supporting the main steel frame layer (2) on three closely spaced steel frames and firmly welding the main steel frame layer (2) to the portal steel frame (21) through an oblique steel plate (26), and at the same time applying a locking anchor rod group (27) on the portal steel frame (21), hanging a steel mesh (28), and spraying C25 early-strength concrete on the steel mesh (28); S6, after the deformation, support, settlement and safety monitoring data are stable, the main tunnel excavation sequence is followed to sequentially remove the columns of the portal steel frame (21), construct the arch layer on the top of the main tunnel and spray concrete, and firmly connect the arch layer on the top of the main tunnel with the main steel frame layer (2).