A segment structure and a construction method thereof

Abstract

The application discloses a pipe piece structure and a construction method thereof, and solves the problem of insufficient bearing capacity of a vertical shaft pipe piece structure and incapability of adjusting the posture of the vertical shaft in the prior art. The pipe piece structure comprises an outer frame, the outer support surface of the outer frame is an open surface, a plurality of grid cavities are arranged in the outer frame, a capsule structure capable of filling and discharging medium is arranged in the grid cavities, and the capsule structure faces the open surface of the outer frame; the plurality of outer frames can be spliced into a pipe piece whole ring, and a communication channel capable of being selectively turned on and turned off is arranged between the capsule structures of adjacent pipe piece whole rings. The pipe piece structure of the application forms an outer frame and inner core structure under different media through the structure of the outer frame and the inner capsule, reduces the self weight of a large and deep vertical shaft structure under the condition of ensuring the bearing capacity, and enhances the strength of the vertical shaft structure through the parameters of the medium pressure and material of the capsule filling / replacement. The capsule structure is arranged in the outer frame in a partitioned manner, the medium is filled and discharged at a fixed point, the acting force between the capsule structure and the stratum is changed, and the purpose of adjusting the posture of the pipe piece structure in the circumferential direction is achieved.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, and in particular to a segment structure and shaft construction method. Background Technology

[0002] Currently, most shaft structures adopt precast reinforced concrete segment structures. However, as the depth and diameter of shafts increase, the shaft segments need to be thicker and heavier to withstand stronger water and soil pressure. To reduce the weight of shaft structures while ensuring the safety of the structural system, hollow segment structures have been proposed. Hollow segment structures with different functions have also been proposed in other scenarios.

[0003] In existing technologies, such as the precast hollow concrete tunnel segment and its precasting method disclosed in CN110593897A, airbags are used to form cavities during the casting of the tunnel segments. The main load-bearing structure is the tunnel segment itself. However, this method has weak points in the stress distribution of large-diameter / deep vertical shaft structures, and safety cannot be guaranteed. Another example is the inflatable seismic isolation tunnel lining structure and construction method disclosed in CN110939457A. This method is mainly used for seismic resistance of tunnel segments, achieving flexible load-bearing through airbags and damping rods. However, in the strata of a vertical shaft structure, the external pressure gradually changes from top to bottom, and the resistance requirements for the airbags and damping rods of each tunnel segment are different. Therefore, the joints of this structure are weak points, and flexible load-bearing will lead to increased shear force at the structural joints. A prefabricated hollow segment structure with publication number CN112253131A is formed by assembling hollow segments in the early stage and filling them with materials in the later stage to form a vertical shaft structure. However, the forming process of the vertical shaft structure is complicated, the circumferential connection structure of the segments is weak, the structural strength at the connection is low, and the vertical connection relies on material filling, which cannot guarantee the reliability of the connection between the ring segments. In water-rich strata, there may be water seepage.

[0004] In summary, the existing vertical shaft segment connection method has weak points in stress, insufficient load-bearing capacity, cannot guarantee the reliability of the ring-to-ring segment connection, and cannot allow for active adjustment of the vertical shaft structure, affecting construction efficiency and construction safety. Summary of the Invention

[0005] To address the shortcomings in the aforementioned background technology, this invention proposes a segment structure and its construction method, which solves the problems of insufficient load-bearing capacity and inability to adjust the vertical shaft posture in existing vertical shaft segment structures.

[0006] The technical solution of this invention is implemented as follows: A segment structure includes an outer frame, the outer supporting surface of which is an open surface. The outer frame contains several grid cavities, each containing a bladder structure capable of holding a medium. The bladder structures face the open surface of the outer frame. The bladder structures are filled with a medium at a certain pressure, which expands to support the frame structure. By changing the parameters of the medium within the bladders, the segments can perform different functions. Several outer frames can be assembled into a complete segment ring. Adjacent segments have selectively open / closed connecting channels between their bladder structures. When the connecting channels are open, the bladder structures of adjacent segments are connected; when closed, they are not connected. The bladder structures between segments can be interconnected. A single / two-ring segment structure requires only at least two inlet / outlet pipes, allowing for the injection of different pressures into segments at different depths to counteract lateral formation pressure. This avoids situations where the entire shaft segment structure is subjected to the same pressure, resulting in excessively high or insufficient pressure at different depths.

[0007] Further preferably, the outer frame is a frame structure II consisting of an inner top plate and an outer side plate, with the outer support surface being an open surface. The inner top plate forms the inner support surface of the outer frame. Several grid cavities are formed within the outer frame by fixedly installed grid support plates. This achieves a zoned arrangement of the bladder structure, allowing for adjustment of the shaft's orientation through targeted filling and releasing of media.

[0008] In a further preferred embodiment, the grid cavities are arranged in N rows and M columns, where N≥1 and M≥2. The cystic structures in the M grid cavities in the same row form a cystic unit. The M cystic structures in the same cystic unit are interconnected. The two cystic structures in the same cystic unit located on both sides are respectively provided with an inlet pipe and an outlet pipe.

[0009] In a further preferred embodiment, the grid cavities are arranged in N rows and M columns, where N≥1 and M≥2. The cystic structures within the N grid cavities in the same column form a cystic unit. The N cystic structures in the same cystic unit are interconnected. The two cystic structures in the same cystic unit located on both sides are respectively provided with an inlet pipe and an outlet pipe.

[0010] Further preferred, two adjacent capsule structures in the same capsule unit are connected by a connecting pipe, the grid support plate is provided with a slot for the connecting pipe to pass through, and the inner support surface of the outer frame is provided with a channel for the inlet pipe and the outlet pipe to pass through.

[0011] Further preferably, the capsule structure includes a rigid fixing plate assembly and a flexible capsule, with the rigid fixing plate assembly fixed to the outer wall of the flexible capsule; the rigid fixing plate assembly matches the mesh cavity, and the flexible capsule faces the outer support surface of the outer frame. The volume of the flexible capsule may change under different medium pressures, and there may be cases where it protrudes from the outer wall of the tube segment.

[0012] Further preferably, the rigid fixing plate assembly includes several peripheral side plates, which are fixed to the periphery of the flexible bladder; the flexible bladder is inserted into the grid cavity through the peripheral side plates; a valve body is provided on the side of the flexible bladder facing the outer support surface of the outer frame to prevent excessive pressure inside the bladder and to add a lubricating layer between the formation and the pipe segment, which can reduce friction to a certain extent.

[0013] Further preferably, the grid cavity is rectangular or circular, and the rigid fixing plate assembly is a corresponding rectangular frame structure or circular frame structure; the rigid fixing plate assembly is embedded in the grid cavity of the outer frame through a flexible bladder that expands by filling with a medium, and the expanded flexible bladder, together with the outer frame, forms a frame tube structure with a pressurized core support.

[0014] A construction method for the aforementioned segment structure includes the following steps: S1 Assembling the segment structure: The capsule structures are placed in the corresponding grid cavities within the outer frame according to the segment design. Adjacent capsule structures of the same capsule unit are connected in series via connecting pipes. Corresponding inlet and outlet pipes are connected to two capsule structures of the same capsule unit located on both sides. Then, a certain gas pressure is applied to the capsule structure through the inlet pipe, so that the capsule structure is embedded in the grid cavity within the outer frame through its rigid fixing plate assembly, thus completing the segment structure assembly. A sealing structure is set between two adjacent segment structures. Finally, the two adjacent segment structures are fixed to gradually form a shaft structure.

[0015] S2 segment assembly and excavation: The upper lifting device lifts the shaft structure and lowers it. During the descent, the shaft structure is monitored by the posture detection device. When the shaft structure deviates, the air volume of the bladder structure in the grid cavity of the segment structure at the corresponding position is adjusted to change the force between the segment structure and the stratum at the corresponding position, thereby adjusting the posture of the shaft structure and ensuring that the shaft structure is excavated accurately.

[0016] S3 segment bladder medium replacement: After the shaft structure is excavated to the correct position, cement grout is injected into the flexible bladder through the inlet pipe of the bladder structure, and the gas in the bladder structure is discharged through the outlet pipe, increasing the self-weight of the shaft structure; further increasing the grout pressure in the flexible bladder, causing the bladder volume to expand outward and embed into or press against the surrounding strata, increasing the circumferential resistance of the shaft structure, reducing the difficulty of bottom sealing, and eliminating the need to construct anti-buoyancy piles.

[0017] During the segment assembly and tunneling process in step S2, when underwater tunneling is underway, gas is injected into the flexible bladder, increasing the buoyancy of the segment structure underwater and further reducing the self-weight of the shaft structure, thus reducing the lifting force of the upper lifting device. When encountering strata with high circumferential frictional resistance, and the shaft structure cannot descend, the internal pressure of the bladder structure is increased, and then the valve body facing the strata is opened. The medium inside the bladder structure is discharged through the valve body, forming a lubricating film around the shaft, reducing the frictional resistance between the shaft structure and the strata, and allowing the shaft structure to sink.

[0018] Method for calculating lateral pressure on formations: During the sinking of the shaft structure, assuming the difference in the internal friction angle of the formation at two points 90° apart on the shaft structure is 'a', then the maximum value of the lateral pressure coefficient of the formation around the shaft structure at the same depth is calculated.

[0019] Among them, K max This represents the maximum lateral pressure coefficient of the formation surrounding a vertical shaft at the same depth.

[0020] The internal friction angle of the stratum at the target point;

[0021] 'a' represents the difference in the internal friction angle of the strata at two points that are 90° apart, and 'a' ranges from 4° to 8°.

[0022] Substituting the values ​​into the load calculation formula, the maximum lateral water and soil pressure on shafts at different depths is obtained.

[0023]

[0024] Among them, P max This represents the maximum lateral pressure of the formation surrounding the shaft at the same depth.

[0025] ∑γh represents the total gravity of the strata at the target point;

[0026] γ 水 h represents the water pressure in the formation at the target point;

[0027] but At that time, the capsule structure (2) opens towards the stratum; wherein, P 囊 Inject pressure values ​​into flexible capsules at the same depth.

[0028] The beneficial effects of this invention are as follows: The segment structure of this invention, through an outer frame + inner bladder structure, forms an outer frame and inner core structure under different media. While ensuring load-bearing capacity, it further reduces the self-weight of large and deep vertical shaft structures. By adjusting parameters such as the pressure and material of the filling / replacement medium in the bladder, the strength of the vertical shaft structure is enhanced. The bladder structure of this invention is partitioned within the outer frame. By filling and releasing the medium at fixed points, the interaction force between the bladder and the strata is changed, achieving the purpose of circumferential adjustment of the segment structure's posture and ensuring high-precision tunneling of the vertical shaft structure. This invention provides a construction method for vertical shaft segment structures. Combined with the engineering project environment, by changing the bladder medium and bladder volume, it provides multiple selection modes for large and deep vertical shaft construction, achieving safer and faster operations. Attached Figure Description

[0029] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic elevation view of the segment structure of the present invention;

[0031] Figure 2 This is a cross-sectional schematic diagram of the segment structure of the present invention;

[0032] Figure 3 This is a schematic elevation view of the outer frame of the present invention;

[0033] Figure 4 This is a schematic diagram of the capsule structure of the present invention;

[0034] Figure 5 This is a schematic diagram of the capsule unit in Example 2;

[0035] Figure 6 A schematic diagram of the cyst unit in its expanded and bulging state;

[0036] Figure 7 This is a structural diagram illustrating the shaft construction process;

[0037] Figure 8 A schematic diagram of the completed shaft construction;

[0038] Figure 9 This is a schematic diagram of the capsule unit in Example 3. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] like Figure 1 , 2As shown in Embodiment 1, a segment structure includes an outer frame 1. The outer frame serves as a connector between segments, and the segments can be connected by welding or bolting. The outer support surface of the outer frame 1 is an open surface; the outer support surface is the side of the segment structure facing the formation. The outer frame 1 contains several grid cavities 1-1, each containing a capsule structure 2 capable of holding a medium. The capsule structure 2 faces the open surface of the outer frame 1. The capsule structure is filled with a medium at a certain pressure to expand and support the frame structure. By changing the parameters of the medium within the capsule structure, the segments can perform different functions. By filling and replacing the medium within the capsule structure, the expanded capsule can fill the entire grid cavity structure, forming a pressurized core supporting the frame structure and resisting the surrounding formation pressure. The volume of the capsule changes under different medium pressures, and some capsules may protrude from the outer wall of the segment. The grid cavity design achieves the partitioning of the capsule structure. By filling and releasing the medium at different locations of the capsule structure, the interaction force between it and the formation is changed, achieving the purpose of circumferentially adjusting the orientation of the segment structure.

[0041] In this embodiment, as one implementation method, several outer frames 1 can be spliced ​​into a complete segment ring. A selectively open / closed connecting channel is provided between the bladder structures 2 of adjacent segment rings. When the connecting channel is open, the bladder structures of adjacent segment rings are connected; when the connecting channel is closed, the bladder structures of adjacent segment rings are not connected. The connection of this channel can be controlled by a valve. Taking a circular segment ring as an example, multiple outer frames are spliced ​​circumferentially to form a circular segment ring. During shaft construction, the bladder structures on two adjacent circular segment rings are connected, meaning the bladder structures between segment structures can be connected. One / two-ring segment structures only require at least two inlet / outlet pipes, thereby injecting different pressures into the bladders of segment structures at different depths to counteract the lateral pressure of the formation, avoiding the entire shaft segment structure being under the same pressure, resulting in excessive or insufficient pressure at different depths; thus improving the stability of the shaft segments.

[0042] This embodiment is one implementation method, such as... Figure 3As shown, the outer frame 1 is a frame structure II with an open outer support surface, consisting of an inner top plate and an outer side plate. This frame structure II provides support for the bladder structure while simultaneously connecting and fixing adjacent segment structures. When used for shaft construction, the outer frame is an arc-shaped frame. The outer arc surface of the arc-shaped frame has an open structure, while the other surfaces are plate structures, forming a five-sided steel frame structure. The inner top plate is set on the inner arc surface of the arc-shaped frame, forming the inner support surface of the outer frame 1. Several grid cavities 1-1 are formed inside the outer frame 1 by fixedly installed grid support plates 11. The grid support plates 11 can be fixed to the inner top plate and outer side plates in a certain format using inner support plates, thus partitioning the interior of the outer frame. Each grid cavity contains a corresponding bladder structure for fixed-point installation. By adjusting the filling and discharging medium of the bladder at the fixed position, the force exerted on the strata is changed, altering its position relative to the strata, thereby adjusting the descent attitude of the shaft structure.

[0043] The medium inside the capsule takes different forms depending on the engineering conditions. When reducing the self-weight of the shaft structure underwater, gas can be injected into the capsule to use buoyancy to counteract the excessive weight of the shaft structure. For shaft structures with insufficient sinking force, high-density slurry, such as cement slurry, can be injected into the capsule to increase the self-weight of the shaft structure and meet the sinking force requirements.

[0044] like Figure 5 As shown in Embodiment 2, a tubular structure is further optimized based on Embodiment 1. In this embodiment, the grid cavities 1-1 are arranged in N rows and M columns, where N≥1 and M≥2. The bladder structures 2 within the M grid cavities 1-1 in the same row form a bladder unit. The M bladder structures 2 within the same bladder unit are interconnected. Specifically, two adjacent bladder structures 2 within the same bladder unit are connected by a connecting pipe 24 to form a series bladder structure. The two bladder structures 2 located on opposite sides of the same bladder unit are respectively provided with an inlet pipe 23-1 and an outlet pipe 23-2. The grid support plate 11 has slots for the connecting pipe 24 to pass through, and the inner support surface of the outer frame 1 has channels for the inlet pipe 23-1 and the outlet pipe 23-2 to pass through.

[0045] In this embodiment, taking N=2 and M=4 as an example, the outer frame structure is a 5-sided steel body with an internal steel support plate forming a grid support plate. It is divided into 8 cavity structures to form 8 grid cavities. The 4 cysts of the same cyst unit are connected in series through connecting pipes to form a whole. Inlet and outlet pipes are arranged on both sides of the cysts. There are two cyst units in the outer frame structure. When injecting the medium, it can be injected simultaneously through the inlet and outlet pipes on both sides. When replacing the medium, it can be injected through the inlet pipe of the leftmost cyst and discharged through the outlet pipe of the rightmost cyst.

[0046] like Figure 9As shown in Embodiment 3, a tubular structure is provided, wherein the grid cavities 1-1 are arranged in N rows and M columns, where N≥1 and M≥2. N bladder structures 2 within the same column of grid cavities 1-1 form a bladder unit. The N bladder structures 2 within the same bladder unit are interconnected. Two bladder structures 2 located on opposite sides of the same bladder unit are respectively provided with an inlet pipe 23-1 and an outlet pipe 23-2. Adjacent bladder structures 2 within the same bladder unit are connected by a connecting pipe 24. The grid support plate 11 has slots for the connecting pipe 24 to pass through, and the inner support surface of the outer frame 1 has channels for the inlet pipe 23-1 and the outlet pipe 23-2 to pass through.

[0047] In this embodiment, taking N=2 and M=4 as an example, the outer frame structure is a 5-sided steel body with an internal steel support plate forming a grid support plate, dividing the structure into 8 cavity structures forming 8 grid cavities. Two bladders of the same bladder unit are connected in series through connecting pipes to form a whole. Inlet and outlet pipes are arranged on the upper and lower bladders, so there are four bladder units in the outer frame. When injecting the medium, it can be injected simultaneously through the inlet and outlet pipes on both sides. When replacing the medium, it can be injected through the inlet pipe of the uppermost bladder and discharged through the outlet pipe of the lowermost bladder.

[0048] like Figure 4 As shown in Example 4, a segment structure is further optimized based on Examples 2 or 3. In this example, the capsule structure 2 includes a rigid fixing plate assembly 21 and a flexible capsule 22. The rigid fixing plate assembly 21 is fixed to the outer wall of the flexible capsule 22 and faces the inner support surface of the outer frame, providing support for the flexible capsule 22. The rigid fixing plate assembly 21 matches the grid cavity 1-1, forming a plug-in fit structure for easy capsule fixation. The flexible capsule 22 faces the outer support surface of the outer frame 1. By applying a certain medium pressure to the flexible capsule 22, the flexible capsule expands, and its rigid fixing plate assembly 21 is embedded in the grid cavity of the frame structure. The flexible capsule 22 can be composed of deformable structures such as fiber bags or thin-walled steel plates. The medium inside the capsule is filled and replaced through inlet and outlet pipes. After expansion, the capsule can fill the entire cavity structure, forming a pressurized core supporting the frame structure and resisting the surrounding formation pressure. The volume of the capsule will change under different medium pressures, and there may be cases where it protrudes from the outer wall of the segment.

[0049] like Figure 6As shown in this embodiment, as one implementation method, the rigid fixing plate assembly 21 includes several peripheral side plates. When the grid cavity is rectangular, the rigid fixing plate assembly 21 may include four peripheral side plates, with a gap between two adjacent peripheral side plates. When the grid cavity is circular, the rigid fixing plate assembly 21 may include two semi-circular peripheral side plates or multiple straight side plates, with a gap between two adjacent peripheral side plates, to meet the requirement that the flexible bladder expands and secures the peripheral side plates within the grid cavity. The peripheral side plates are fixedly connected to the flexible bladder 22 along the circumferential direction. The flexible bladder 22 is inserted into the grid cavity 1-1 through the peripheral side plates, and then the expansion of the bladder causes the peripheral side plates to expand outward to achieve the purpose of fixing it within the grid cavity.

[0050] Alternatively, as another implementation, the rigid fixing plate assembly 21 is a frame structure I with an open outer support surface composed of peripheral side plates, and a top plate can be selectively used. This frame structure I is similar to the frame structure II. When a top plate is used, the side plates and the top plate can be a five-sided steel plate structure. The flexible bladder 22 is directly fixed in the grid cavity by a tight insertion method. The peripheral side plates are fixedly connected to the flexible bladder 22. A valve body 25 is provided on the side of the flexible bladder 22 facing the outer support surface of the outer frame 1. This valve body can be a pressure relief valve, which automatically opens when the pressure inside the bladder exceeds a certain value, allowing the medium inside the bladder to be discharged; or a pressure reducing valve can be used. When encountering a stratum with high peripheral friction and unable to descend, the pressure inside the bladder is increased to discharge the medium in the bladder, such as bentonite slurry, gas, or other lubricating media, forming a lubricating film on the periphery of the shaft to reduce the friction between the shaft and the stratum, allowing the shaft structure to sink.

[0051] In this embodiment, as one implementation method, the grid cavity 1-1 is rectangular or circular. Taking a rectangular grid cavity 1-1 as an example, the rigid fixing plate assembly 21 is a corresponding rectangular or circular frame structure. Similarly, taking a rectangular frame structure as an example, the rigid fixing plate assembly 21 is embedded within the grid cavity 1-1 of the outer frame 1 through a flexible bladder 22 that expands with a medium. The expanded flexible bladder 22, together with the outer frame 1, forms a frame segment structure with a pressurized core support. Each shaft segment structure can be injected with different media according to engineering requirements to form different core structures. For example, fiber-reinforced concrete significantly improves concrete performance. For deep shaft construction, high-grade concrete slurry can be injected to form a fiber-reinforced concrete structure, improving the bearing capacity of the shaft structure and meeting the stress requirements of deep shaft structures.

[0052] Example 5, a construction method for a segment structure as described in Example 4, comprising the following steps: S1 Assembling the segment structure: The capsule structures 2 are placed in the corresponding grid cavities 1-1 within the outer frame 1 according to the segment design. Adjacent capsule structures 2 of the same capsule unit are connected in series via connecting pipes 24. Corresponding inlet pipes 23-1 and outlet pipes 23-2 are connected to two capsule structures 2 of the same capsule unit located on opposite sides. A certain gas pressure is then applied to the capsule structure 2 through the inlet pipe 23-1, causing the capsule structure 2 to be embedded in the grid cavity 1-1 within the outer frame 1 via its rigid fixing plate assembly 21, thus completing the segment structure assembly. A sealing structure is set between two adjacent segment structures, and finally, the two adjacent segment structures are fixed, gradually forming a shaft structure. Segment connections can be made using welding, bolting, or other methods for fixing. Figure 7 As shown.

[0053] S2 segment assembly and excavation: The upper lifting device lifts the shaft structure and lowers it. During the descent, the shaft structure is monitored by the posture detection device. When the shaft structure deviates, the air volume of the bladder structure 2 in the grid cavity 1-1 of the segment structure at the corresponding position is adjusted to change the force between the segment structure and the stratum 4 at the corresponding position, thereby adjusting the posture of the shaft structure and ensuring that the shaft structure is excavated accurately.

[0054] During the segment assembly and tunneling process in step S2, when underwater tunneling is being carried out, gas is injected into the flexible bladder 22, increasing the buoyancy of the segment structure underwater, further reducing the self-weight of the shaft structure, reducing the lifting force of the upper lifting device, and reducing costs. For large and deep shafts, according to design requirements, the segment structure can be arranged in a ring-like manner, and the lifting device, in conjunction with the segment structure, is more conducive to controlling the attitude of the segments.

[0055] When encountering a formation with high circumferential frictional resistance, and the shaft structure cannot descend, the internal pressure of the capsule structure 2 is increased, and then the valve body of the capsule structure 2 facing the formation is opened. The lubricating medium inside the capsule structure 2, such as bentonite slurry or gas, is discharged through the valve body, forming a lubricating film on the periphery of the shaft, reducing the frictional resistance between the shaft structure and the formation, and causing the shaft structure to sink.

[0056] S3 segment slab cavity media replacement: After the shaft structure is excavated to its position, cement grout 3 is injected into the flexible cavity 22 through the inlet pipe of cavity structure 2, and the gas in cavity structure 2 is discharged through the outlet pipe, increasing the self-weight of the shaft structure; further increasing the grout pressure inside the flexible cavity 22, causing the cavity volume to expand outward and embed into or press against the surrounding strata, increasing the circumferential resistance of the shaft structure, reducing the difficulty of bottom sealing, and eliminating the need for anti-buoyancy pile construction, such as Figure 8As shown. Existing construction methods, such as large bottom sealing and the installation of anti-buoyancy piles, are economical and have low construction safety. Therefore, the anti-buoyancy effect can be enhanced by replacing the bladder in this structure. The construction method of the shaft segment structure, combined with the project environment, provides multiple options for the construction of large and deep shafts by changing the bladder medium and volume, achieving safer and faster operation.

[0057] The valve body on the outside of the caisson, facing the stratum, is a one-way valve. It only opens when the pressure inside the caisson exceeds the lateral pressure of the stratum, allowing the medium inside to be injected into the gap between the shaft and the stratum. Therefore, according to the standards "Design Code for Reinforced Concrete Caisson Structures of Water Supply and Drainage Engineering CECS137-2015" and "Construction Code for Caissons and Pneumatic Caissons GBT51130-2016", the horizontal internal force of the well wall during the sinking of a circular caisson without partition walls can be calculated by taking closed loops at different heights. Assuming the difference in the internal friction angle of the stratum at two points at 90° to each other is 'a', typically taken as 4°–8°, the maximum lateral pressure coefficient is obtained.

[0058]

[0059] Among them, K max This represents the maximum lateral pressure coefficient of the formation surrounding a vertical shaft at the same depth.

[0060] The internal friction angle of the stratum at the target point;

[0061] 'a' represents the difference in the internal friction angles of the strata at two points that are 90° apart.

[0062] Substituting the values ​​into the load calculation formula, the maximum lateral soil and water pressure at different depths is obtained as follows:

[0063]

[0064] Among them, P max This represents the maximum lateral pressure of the formation surrounding the shaft at the same depth.

[0065] ∑γh represents the total gravity of the strata at the target point;

[0066] γ 水 h represents the water pressure in the formation at the target point;

[0067] Therefore, as long as the pressure within the capsule exceeds the maximum lateral soil and water pressure at that depth, the valve on the outer side of the capsule facing the stratum will open, i.e.

[0068]

[0069] Among them, P 囊 Inject pressure values ​​into the cyst at this depth.

[0070] After the bladder medium leaks out through the valve body, it diffuses to areas of lower pressure, that is, it escapes upward from the gap behind the well wall, thereby forming a lubricating film around the shaft. It can also perform slurry replacement operation behind the wall after the well reaches the designed position.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A segmental structure, characterized in that: Includes an outer frame (1), the outer support surface of the outer frame (1) is an open surface, the outer frame (1) is provided with a number of grid cavities (1-1), the grid cavities (1-1) are provided with a capsule structure (2) that can be filled with a medium, the capsule structure (2) faces the open surface of the outer frame (1); the number of outer frames (1) can be spliced ​​into a tube ring, and the capsule structures (2) of the adjacent tube rings are provided with a selectively open and closed connecting channel; The outer frame (1) is a frame structure II with an open outer support surface, consisting of an inner top plate and an outer side plate. The inner top plate forms the inner support surface of the outer frame (1). Several grid cavities (1-1) are formed inside the outer frame (1) by a fixed grid support plate (11). The grid cavities (1-1) are arranged in N rows and M columns, where N≥1 and M≥2. The cystic structures (2) in the M grid cavities (1-1) in the same row form a cystic unit, and the M cystic structures (2) in the same cystic unit are interconnected. Alternatively, the grid cavities (1-1) are arranged in N rows and M columns, where N≥1 and M≥2. The cystic structures (2) in the N grid cavities (1-1) in the same column form a cystic unit, and the N cystic structures (2) in the same cystic unit are interconnected. An inlet pipe (23-1) and an outlet pipe (23-2) are respectively provided on two cyst structures (2) located on both sides of the same cyst unit. The capsule structure (2) includes a rigid fixing plate assembly (21) and a flexible capsule (22). The rigid fixing plate assembly (21) is fixed on the outer wall of the flexible capsule (22). The rigid fixing plate assembly (21) matches the grid cavity (1-1), and the flexible capsule (22) faces the outer support surface of the outer frame (1).

2. The segment structure according to claim 1, characterized in that: Two adjacent bladder structures (2) in the same bladder unit are connected by a connecting pipe (24). The grid support plate (11) is provided with a slot for the connecting pipe (24) to pass through. The inner support surface of the outer frame (1) is provided with a channel for the inlet pipe (23-1) and the outlet pipe (23-2) to pass through.

3. The segment structure according to claim 1, characterized in that: The rigid fixing plate assembly (21) includes several peripheral side plates, which are fixed to the periphery of the flexible bladder (22); the flexible bladder (22) is inserted into the mesh cavity (1-1) through the peripheral side plates; a valve body (25) is provided on the side of the flexible bladder (22) facing the outer support surface of the outer frame (1).

4. The segment structure according to claim 3, characterized in that: The grid cavity (1-1) is rectangular or circular, and the rigid fixing plate assembly (21) is a corresponding rectangular frame structure or circular frame structure; the rigid fixing plate assembly (21) is embedded in the grid cavity (1-1) of the outer frame (1) through a flexible bladder (22) that expands by filling with medium, and the expanded flexible bladder (22) cooperates with the outer frame (1) to form a frame tube structure with a pressurized core support.

5. A construction method for a segment structure as described in any one of claims 1 to 4, characterized in that: The steps are as follows: S1 Assemble the segment structure: Place the capsule structure (2) into the grid cavity (1-1) of the corresponding outer frame (1) according to the segment design form. Connect adjacent capsule structures (2) of the same capsule unit in series through connecting pipe (24). Connect the corresponding inlet pipe (23-1) and outlet pipe (23-2) on the two capsule structures (2) of the same capsule unit located on both sides. Then apply a certain gas pressure to the capsule structure (2) through the inlet pipe (23-1) so that the capsule structure (2) is embedded in the grid cavity (1-1) of the outer frame (1) through its rigid fixing plate assembly (21) to complete the segment structure assembly; set a sealing structure between two adjacent segment structures, and finally fix the two adjacent segment structures to gradually form a vertical shaft structure; S2 segment assembly and excavation: The upper lifting device lifts the shaft structure and lowers it. During the descent, the shaft structure is detected by the posture detection device. When the shaft structure is tilted, the air volume of the bladder structure (2) of the grid cavity (1-1) on the corresponding position of the segment structure is adjusted to change the force between the segment structure and the stratum at the corresponding position, adjust the posture of the shaft structure, and ensure that the shaft structure is excavated accurately. S3 segment bladder medium replacement: After the shaft structure is excavated to the position, cement slurry is injected into the flexible bladder (22) through the inlet pipe of the bladder structure (2), and the gas in the bladder structure (2) is discharged through the outlet pipe, increasing the self-weight of the shaft structure; further increasing the slurry pressure in the flexible bladder (22), causing the bladder volume to expand outward and embed or press against the surrounding strata, increasing the circumferential resistance of the shaft structure, reducing the difficulty of bottom sealing, and eliminating the need to carry out anti-buoyancy pile operations.

6. The construction method for the segment structure according to claim 5, characterized in that: During the tunneling process of segment assembly in step S2, when underwater tunneling is carried out, gas is injected into the flexible bladder (22), the buoyancy of the segment structure underwater increases, further reducing the self-weight of the shaft structure and reducing the lifting force of the upper lifting device; When encountering a formation with high lateral frictional resistance, the shaft structure cannot descend. Increase the internal pressure of the capsule structure (2). When the pressure inside the capsule structure (2) is greater than the lateral pressure of the formation, the valve of the capsule structure (2) opens towards the formation. The medium inside the capsule structure (2) is discharged through the valve, forming a lubricating film on the periphery of the shaft, reducing the frictional resistance between the shaft structure and the formation, and causing the shaft structure to sink. Method for calculating lateral pressure on formations: During the sinking of the shaft structure, assuming the difference in the internal friction angle of the formation at two points 90° apart on the shaft structure is 'a', then the maximum value of the lateral pressure coefficient K of the formation surrounding the shaft structure at the same depth is calculated. max = tan 2 (45° - (φ - a) / 2), Among them, K max This represents the maximum lateral pressure coefficient of the formation surrounding a vertical shaft at the same depth. φ is the internal friction angle of the stratum at the target point; 'a' represents the difference in the internal friction angle of the strata at two points that are 90° apart, and 'a' ranges from 4° to 8°. Substituting the values ​​into the load calculation formula, the maximum lateral water and soil pressure on shafts at different depths is obtained. P max =K max ·∑γh + γ 水 h =tan 2 (45°-(φ-a) / 2)·∑γh+ γ 水 h Among them, P max This represents the maximum lateral pressure of the formation surrounding the shaft at the same depth. ∑γh represents the total gravity of the strata at the target point; γ 水 h represents the water pressure in the formation at the target point; Then P 囊 ≥P max =tan 2 (45°-(φ-a) / 2)·∑γh+ γ 水 At time h, the capsule structure (2) opens towards the formation as a valve; where P 囊 Inject pressure values ​​into flexible capsules at the same depth.

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