Method for connecting a vertical shaft to an electrically powered shield tunnel

Abstract

This application relates to a method for connecting vertical shafts in a power shield tunnel, comprising the following steps: excavating the shield tunnel according to the designed route, and splicing concrete segments and steel segments into a ring inside the shield tunnel, positioning the steel segments at the location of a pre-designated power shaft, wherein the steel segments and concrete segments are detachably connected, and the steel segments have openings; after the shield tunnel construction is completed, excavating the shaft downwards at the corresponding pre-designated power shaft location until the connection point between the shaft and the shield tunnel is reached, and simultaneously constructing the initial support concrete wall of the shaft; pre-embedding grouting pipes in the lower part of the shaft and grouting; setting up formwork and pouring concrete, and completing the shaft construction once the concrete strength of the shaft reaches the design strength; removing the openings to form the connection point between the shaft and the shield tunnel.

Description

Technical Field

[0001] This application relates to the field of shaft construction technology, specifically to a method for connecting shafts in a power shield tunnel. Background Technology

[0002] With the rapid development of urban power grid construction, power tunnels have gradually become an important part of urban power transmission and distribution networks. Due to its advantages such as minimal disturbance to ground traffic and the surrounding environment and fast construction speed, the shield tunneling method is widely used in the construction of power tunnels. During the operation phase, power tunnels require the installation of a large number of vertical shafts for cable connection, equipment installation, and ventilation and maintenance. These shafts are usually small in diameter, and their construction locations need to be flexibly arranged according to the specific location of the cable joints.

[0003] In related technologies, the traditional construction method for power tunnel shafts involves constructing a shield tunneling launch shaft before the shield machine begins excavation. The shield machine launches from these large shafts to complete the tunnel excavation, and then the large-sized shield launch shaft is converted into a small-sized power tunnel shaft. The size of the shield launch shaft is much larger than the actual needs of the power tunnel shaft, resulting in a huge waste of space resources. The power tunnel shaft must coincide with the location of the shield launch shaft, and it cannot be flexibly set up along the tunnel according to the actual needs of cable wiring. Additional transverse channels need to be added to connect the power tunnel shaft, increasing construction costs and time. After the shield tunnel is completed, the shaft is constructed by opening an opening, which requires large-scale reinforcement of the soil around the tunnel, followed by manual removal of concrete segments. This not only has a long construction period and high cost, but also easily damages the overall tunnel structure during the removal process, causing safety accidents such as segment cracking, water leakage, or even tunnel collapse.

[0004] Therefore, it is necessary to design a new method for connecting the vertical shafts of electric shield tunnels to overcome the above problems. Summary of the Invention

[0005] This application provides a method for connecting vertical shafts in power shield tunnels, which can solve the problems in the traditional construction method of power tunnel vertical shafts, which requires the construction of the shield launching shaft before the shield tunneling, occupying a large amount of space resources, and the power tunnel vertical shaft must coincide with the location of the shield launching shaft, making it impossible to flexibly set up along the tunnel according to the actual needs of cable wiring. After the shield tunnel construction is completed, the vertical shaft is constructed by opening a hole, which requires manual chiseling of concrete segments, and the chiseling process is very easy to damage the overall structure of the tunnel.

[0006] In a first aspect, embodiments of this application provide a method for connecting vertical shafts in a power shield tunnel, which includes the following steps: The shield tunnel is excavated according to the designed route, and concrete segments and steel segments are spliced ​​into a ring inside the shield tunnel, so that the steel segments are located at the pre-set power shaft position. The steel segments and concrete segments are detachably connected, and the steel segments are equipped with opening sections. After the shield tunnel construction is completed, the shaft will be excavated downwards at the corresponding preset power shaft location until the connection between the shaft and the shield tunnel is reached, and the initial support concrete wall of the shaft will be constructed simultaneously. Pre-embed grouting pipes in the lower part of the shaft and inject grout; The formwork is erected and concrete is poured. Once the concrete strength of the shaft reaches the design strength, the shaft construction is completed. The opening section was removed to create a connection between the vertical shaft and the shield tunnel.

[0007] In conjunction with the first aspect, in one embodiment, the steel pipe segment includes a steel pipe segment body and steel pipe segment parts, the steel pipe segment body is bolted to the concrete pipe segment, the steel pipe segment body and the steel pipe segment parts are bolted together, and the steel pipe segment parts form an open section.

[0008] In conjunction with the first aspect, in one implementation, the removal of the opening section to form a connection between the shaft and the shield tunnel includes: Using small tools, the bolts between the main body of the steel segment and the individual steel segments are manually removed, the individual steel segments are dismantled, forming a connection between the shaft and the shield tunnel, and steel bars are inserted into the cavity of the main body of the steel segment and filled with concrete.

[0009] In conjunction with the first aspect, in one embodiment, after the grouting pipe is pre-embedded and grouting is performed at the lower part of the shaft, the following is included: A waterproof layer is wrapped around the side wall of the initial support concrete retaining wall of the shaft, and the vertical reinforcing bars inside the initial support concrete retaining wall of the shaft are welded to the main body of the steel pipe segment.

[0010] In conjunction with the first aspect, in one embodiment, the steel pipe segment is located in the middle of the main body of the steel pipe segment.

[0011] In conjunction with the first aspect, in one embodiment, the steel pipe segment and the concrete pipe segment have the same diameter and the same thickness.

[0012] In conjunction with the first aspect, in one embodiment, the step of excavating the shaft downwards at the location of the corresponding preset power shaft until the connection point between the shaft and the shield tunnel is reached, and simultaneously constructing the initial support concrete retaining wall of the shaft, includes: Excavate downwards from the ground to 0.5-1m above the concrete segment corresponding to the steel pipe segment, and simultaneously construct the initial support concrete wall of the shaft. The thickness of the initial support concrete wall of the shaft is greater than or equal to 150mm.

[0013] In conjunction with the first aspect, in one embodiment, prior to the initial support concrete wall of the construction shaft, the following further step is taken: Temporary supports are installed at the locations corresponding to the steel segments inside the shield tunnel. The temporary supports include interconnected circumferential steel frames and longitudinal connecting steel. The circumferential steel frames are fitted with the inner wall of the concrete segments with a clearance fit. The circumferential steel frames and concrete segments are wedged tightly by steel wedges. The longitudinal connecting steel is supported inside the circumferential steel frames and fixed to the circumferential steel frames.

[0014] In conjunction with the first aspect, in one embodiment, after the grouting pipe is pre-embedded and grouting is performed at the lower part of the shaft, the method further includes: A water-stop steel plate is installed on the inner side of the initial support concrete wall of the shaft, and the water-stop steel plate is welded to the steel pipe segment on both sides.

[0015] In conjunction with the first aspect, in one embodiment, the method for connecting the vertical shaft of the power shield tunnel further includes: The horizontal displacement, vertical settlement, and joint opening of the concrete segments are monitored in real time. If the horizontal displacement, vertical settlement, or joint opening of the concrete segments exceeds the preset threshold, construction is suspended and reinforcement measures are taken.

[0016] The beneficial effects of the technical solutions provided in this application include: By splicing concrete and steel segments into a ring inside the shield tunnel, the steel segments are positioned at the locations of pre-designated power shafts. The steel and concrete segments are detachably connected, with pre-reserved openings in the steel segments. Shaft excavation proceeds directly downwards from the corresponding pre-designated power shaft location, eliminating the need for large-scale shield shaft construction. This allows for flexible shaft placement based on actual cable wiring requirements, without the need to remove concrete segments, thus avoiding damage to the tunnel structure. This solves the technical problems of traditional power tunnel shaft construction methods, which require constructing a shield launch shaft before shield excavation, occupying significant space, necessitating the power tunnel shaft to coincide with the shield launch shaft location (making flexible placement along the tunnel line impossible based on cable wiring needs), and requiring manual removal of concrete segments after shield tunnel construction, which easily damages the overall tunnel structure. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, 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 this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for connecting vertical shafts in a power shield tunnel, as provided in this application embodiment; Figure 2 Cross-sectional views of steel pipe segments and concrete pipe segments provided in embodiments of this application; Figure 3 A top view of the steel pipe segment and concrete pipe segment provided in the embodiments of this application; Figure 4 A schematic diagram of the temporary support provided in the embodiments of this application; Figure 5 This is a schematic diagram of the tunnel shaft and steel pipe segment body provided in the embodiments of this application.

[0019] In the diagram: 1. Concrete segment; 2. Steel segment; 21. Main body of steel segment; 22. Separate steel segment; 3. Initial support concrete wall of shaft; 4. Grouting pipe; 5. Bolt; 6. Temporary support; 61. Circumferential steel frame; 62. Longitudinal connecting steel; 7. Secondary lining of shaft. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0021] This application provides a method for connecting vertical shafts in a power shield tunnel, which solves the problems of traditional power tunnel shaft construction methods, such as constructing the shield launching shaft before shield excavation, which occupies a lot of space resources, requiring the power tunnel shaft to coincide with the shield launching shaft, making it impossible to flexibly set up along the tunnel according to the actual needs of cable wiring, and using open-hole construction of the shaft after shield tunnel construction, which requires manual chiseling of concrete segments, and the process of chiseling is very easy to damage the overall tunnel structure.

[0022] See Figure 1-3 As shown in the figure, this application provides a method for connecting vertical shafts in a power shield tunnel, which includes the following steps: S1: The shield tunnel is excavated according to the design route, and the concrete segment 1 and steel segment 2 are spliced ​​into a ring inside the shield tunnel, so that the steel segment 2 is located at the pre-set power shaft position. The steel segment 2 and the concrete segment 1 are detachably connected, and the steel segment 2 is provided with an opening section.

[0023] S2: After the shield tunnel construction is completed, the shaft will be excavated downwards at the corresponding preset power shaft location until the connection between the shaft and the shield tunnel is reached, and the initial support concrete retaining wall 3 of the shaft will be constructed simultaneously.

[0024] S3: Pre-embed grouting pipe 4 in the lower part of the shaft and grout.

[0025] S4: Set up the formwork and pour the concrete. Once the concrete strength of the shaft reaches the design strength, the shaft construction is complete.

[0026] S5: Remove the opening section to form a connection between the vertical shaft and the shield tunnel.

[0027] In this embodiment, the shield tunnel is excavated according to the designed route. At the pre-planned location where an electrical shaft is to be installed, steel pipe segments 2 are used to replace concrete pipe segments 1, and the steel pipe segments 2 and concrete pipe segments 1 are spliced ​​together to form a ring. Opening sections are reserved in the steel pipe segments 2. After the shield tunnel construction is completed, a safe distance is maintained between the shield tunnel and the shaft to be constructed later. Depending on the geological conditions, methods such as inverted shaft walls, small caissons, or rotary drilling rigs combined with steel casings are used to excavate short sections of the shaft downwards from the ground corresponding to the steel pipe segments 2. Then, a grating steel frame is installed, followed by shotcreting. This process is repeated downwards until the shaft and shield tunnel are reached. At the connection point, the initial support concrete wall 3 of the shaft is constructed simultaneously during the excavation process. Then, grouting pipes 4 are pre-embedded in the lower part of the shaft along the circumference. Grouting is supplemented using grouting pipes 4 according to the geological conditions to ensure a tight connection between the lower part of the shaft and the concrete segment 1, thus ensuring the reinforcement effect. Manual excavation can then be carried out step by step to the top of the tunnel for the final section of shaft wall construction, completing the initial support of the shaft. Concrete is then poured and the formwork is erected. Once the concrete strength of the shaft reaches the design strength, ladders, platforms, lighting, and other auxiliary facilities are installed inside the shaft to complete the shaft construction. Finally, the opening section is removed to form the connection between the shaft and the shield tunnel.

[0028] By eliminating the construction of numerous large-size shield tunnel shafts, the cost of a single small-size shaft is only 1 / 10 to 1 / 7 of that of a traditional shaft. This can save tens of millions of yuan in construction costs for long-distance power tunnel projects. The shaft location can be flexibly adjusted according to the actual needs of cable wiring, without being restricted by the shield tunneling construction process, making the power tunnel line design more reasonable. The steel pipe segment 2 has a reserved opening section, eliminating the need to remove the concrete pipe segment 1, avoiding the damage to the tunnel structure caused by the traditional post-opening method. The overall stress performance of the tunnel is better, effectively protecting the overall tunnel structure. Shield tunneling and shaft construction can be carried out in parallel, and shaft construction does not need to wait for the shield machine to leave the site, significantly shortening the overall construction cycle of the project. Furthermore, the above-described method for connecting shafts in power shield tunnels is applicable to various geological conditions such as soft soil, sandy soil, or silty clay, and has strong practicality and promotional value.

[0029] In other embodiments, steel pipe segments 2 are used around the entire ring at the location where power shafts are planned to be installed, with pre-reserved opening sections in the steel pipe segments 2.

[0030] This embodiment splices concrete segment 1 and steel segment 2 into a ring inside the shield tunnel, positioning the steel segment 2 at the location of a pre-set power shaft. The steel segment 2 and concrete segment 1 are detachably connected, with a pre-reserved opening in the steel segment 2. Shaft excavation is then carried out directly from the corresponding pre-set power shaft location, eliminating the need for large-scale shield shaft construction. This allows for flexible shaft placement based on actual cable wiring requirements, without the need to remove concrete segment 1, thus avoiding damage to the tunnel structure. This solves the technical problems of traditional power tunnel shaft construction methods, which require constructing the shield launch shaft before shield excavation, occupying significant space, necessitating the power tunnel shaft to coincide with the shield launch shaft location (making flexible placement along the tunnel line impossible based on cable wiring needs), and requiring manual removal of concrete segments after shield tunnel construction, which easily damages the overall tunnel structure.

[0031] Further, see Figure 2-5 As shown, in some embodiments, the steel pipe segment 2 includes a steel pipe segment body 21 and a steel pipe segment body 22. The steel pipe segment body 21 is bolted to the concrete pipe segment 1, and the steel pipe segment body 21 and the steel pipe segment body 22 are bolted together. The steel pipe segment body 22 forms an open section.

[0032] In this embodiment, the steel segment 2 is exemplary, made of Q355B steel with an anti-corrosion layer on its surface. The steel segment 2 includes multiple steel segment bodies 21 and steel segment sub-body 22. The number of segments of the steel segment body 21 is determined according to the diameter of the shaft. The steel segment body 21 is connected to the concrete segment 1 by high-strength bolts. Two adjacent steel segment bodies 21 are connected by high-strength bolts, and adjacent steel segment bodies 21 and steel segment sub-body 22 are connected by high-strength bolts.

[0033] Further, see Figure 2 , Figure 3 and Figure 5 As shown, in some embodiments, the removal of the opening section to form a connection between the shaft and the shield tunnel includes: Using small tools, the bolts 5 between the main body 21 and the segment 22 of the steel pipe are manually removed, the segment 22 of the steel pipe is removed, forming a connection between the shaft and the shield tunnel, and steel bars are inserted into the cavity of the main body 21 of the steel pipe and filled with concrete.

[0034] In this embodiment, small tools are used to manually remove the bolts 5 between the main body of the segment and the steel segment 22 to form a connection between the shaft and the shield tunnel. During the removal process, large crushing equipment is strictly prohibited to avoid impact damage to the adjacent main body of the steel segment 21 and the concrete segment 1. After the removal is completed, steel bars are inserted into the cavity of the main body of the steel segment 21 and filled with concrete. The detachable steel segment 2, together with the reserved opening, ensures that no crushing operation is required during the removal process, and there is no disturbance to the tunnel structure, which significantly improves the durability of the tunnel structure and the construction safety.

[0035] Further, see Figure 5 As shown, in some embodiments, after the grouting pipe 4 is pre-embedded in the lower part of the shaft and grouting is performed, the following steps are included: A waterproof layer is wrapped around the side wall of the initial support concrete retaining wall 3 of the shaft, and the vertical reinforcing bars inside the initial support concrete retaining wall 3 of the shaft are welded to the main body of the steel pipe segment 21.

[0036] In this embodiment, as an example, after grouting is completed and there is no leakage, a waterproof layer is set on the side wall of the initial support concrete retaining wall 3 of the shaft. The waterproof layer is located between the initial support concrete retaining wall 3 and the secondary lining 7 of the shaft. Reinforcing bars are set at the connection parts of the secondary lining 7 of the shaft, and the lap length of the reinforcing bars is greater than or equal to 35d (d is the diameter of the reinforcing bar). Then the reinforcing bars of the secondary lining 7 of the shaft are tied, and the vertical reinforcing bars of the shaft are welded to the main body 21 of the steel pipe segment. The length of the vertical reinforcing bars meets the anchorage length requirements to ensure that they are connected to the main body 21 of the steel pipe segment at the bottom of the shaft. Then, concrete is poured in sections. After the concrete strength of the secondary lining 7 of the shaft reaches the design strength and there is no leakage, the steel pipe segment 22 is removed to ensure the safety of the construction process.

[0037] Further, see Figure 2-5 As shown, in some embodiments, the steel pipe segment 22 is located in the middle of the steel pipe segment body 21.

[0038] In this embodiment, preferably, the steel segment 22 is located in the middle of the steel segment body 21, so that the steel segment 22 is directly facing the wellhead of the shaft. This eliminates the need to adjust the progress between shaft excavation and dismantling of the steel segment 22, ensuring the continuity of the construction process.

[0039] Further, see Figure 2 As shown, in some embodiments, the steel pipe segment 2 and the concrete pipe segment 1 have the same diameter and the same thickness.

[0040] In this embodiment, the steel pipe segment 2 and the concrete pipe segment 1 have the same diameter and the same thickness, ensuring the overall alignment and stress continuity of the tunnel.

[0041] Further, see Figure 5As shown, in some embodiments, the step of excavating the shaft downwards at the location of the corresponding preset power shaft until the connection point between the shaft and the shield tunnel is reached, and simultaneously constructing the initial support concrete retaining wall 3 of the shaft, includes: Excavate downwards from the ground corresponding to the steel pipe segment 2 until it is 0.5~1m above the concrete pipe segment 1, and simultaneously construct the initial support concrete retaining wall 3 of the shaft. The thickness of the initial support concrete retaining wall 3 of the shaft is greater than or equal to 150mm.

[0042] In this embodiment, the ground corresponding to the steel pipe segment 2 is excavated downwards. The excavation diameter is determined according to the design dimensions of the shaft. The excavation stops 0.5 to 1m above the concrete pipe segment 1. During the excavation process, the initial support concrete wall 3 of the shaft is constructed simultaneously. The thickness of the initial support concrete wall 3 of the shaft is greater than or equal to 150 mm, and the height of each section of the initial support concrete wall 3 of the shaft is less than or equal to 1m to ensure the stability of the shaft opening.

[0043] Further, see Figure 4 and Figure 5 As shown, in some embodiments, before the initial support concrete wall 3 of the construction shaft, the following is also included: Temporary supports 6 are installed at the positions corresponding to the steel segments 2 inside the shield tunnel. The temporary supports 6 include interconnected circumferential steel frames 61 and longitudinal connecting steel 62. The circumferential steel frames 61 are fitted with the inner wall of the concrete segments 1 with a clearance. The circumferential steel frames 61 and the concrete segments 1 are wedged together by steel wedges. The longitudinal connecting steel 62 is supported inside the circumferential steel frames 61 and fixed to the circumferential steel frames 61.

[0044] In this embodiment, as an example, temporary supports 6 are installed inside the tunnel to reinforce the area corresponding to the steel segment 2 and within a range of 4 to 6 rings before and after it. The circumferential steel frame 61 is made of 120b I-beams, and the longitudinal connecting steel 62 is made of I16 I-beams. The distance between the circumferential steel frame 61 and the concrete segment 1 is less than or equal to 1m. The longitudinal connecting steel 62 welds multiple circumferential steel frames 61 into a whole. The circumferential steel frame 61 and the concrete segment 1 are wedged together with steel wedges to ensure that the temporary supports 6 are subjected to uniform stress. After the temporary supports 6 are completed, the deformation of the concrete segment 1 and the steel segment 2 inside the tunnel is monitored in real time using a pre-embedded monitoring prism to ensure that the reinforcement effect meets the requirements. After the concrete strength of the shaft reaches the design strength, the temporary supports 6 inside the tunnel are removed in the order of bottom to top. During the removal process, the deformation of the concrete segment 1 and the steel segment 2 inside the tunnel is continuously monitored. If abnormal deformation occurs, the removal is stopped immediately and reinforcement measures are taken.

[0045] Further, see Figure 5 As shown, in some embodiments, after the grouting pipe 4 is pre-embedded in the lower part of the shaft and grouting is performed, the following steps are also included: A water-stop steel plate is installed on the inner side of the initial support concrete wall 3 of the shaft, and the water-stop steel plate is welded to the steel pipe segment 2 on both sides.

[0046] In this embodiment, as an example, after the vertical reinforcing bars are welded to the main body 21 of the steel pipe segment, a water-stop steel plate is installed in the middle of the secondary lining 7 of the shaft, and the water-stop steel plate is welded to the main body 21 of the steel pipe segment on both sides to seal the joint between the secondary lining 7 of the shaft and the steel pipe segment 2, thereby ensuring the waterproof performance of the joint.

[0047] Further, see Figure 2-5 As shown, in some embodiments, the method for connecting the vertical shaft of the power shield tunnel further includes: The horizontal displacement, vertical settlement, and joint opening of concrete segment 1 are monitored in real time. If the horizontal displacement, vertical settlement, or joint opening of concrete segment 1 exceeds the preset threshold, construction is suspended and reinforcement measures are taken.

[0048] In this embodiment, during the installation of steel pipe segment 2, the settlement and displacement monitoring points inside the tunnel are set up simultaneously to ensure the quality of tunnel construction. Throughout the construction process, the horizontal displacement, vertical settlement, and joint opening of concrete pipe segment 1 are monitored in real time. If the horizontal displacement of concrete pipe segment 1 is greater than 5 mm, or the vertical settlement of concrete pipe segment 1 is greater than 3 mm, or the joint opening is greater than 2 mm, construction is suspended and reinforcement measures are taken.

[0049] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0050] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0051] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for connecting vertical shafts in a power shield tunnel, characterized in that, It includes the following steps: The shield tunnel is excavated according to the design route, and the concrete pipe segment (1) and steel pipe segment (2) are spliced ​​into a ring inside the shield tunnel, so that the steel pipe segment (2) is located at the preset power shaft position. The steel pipe segment (2) and the concrete pipe segment (1) are detachably connected, and the steel pipe segment (2) is provided with an opening section. After the shield tunnel construction is completed, the shaft is excavated downwards at the corresponding preset power shaft position until the connection between the shaft and the shield tunnel is reached, and the initial support concrete retaining wall of the shaft is constructed simultaneously (3). Pre-embed grouting pipe (4) in the lower part of the shaft and grout; The formwork is erected and concrete is poured. Once the concrete strength of the shaft reaches the design strength, the shaft construction is completed. The opening section was removed to create a connection between the vertical shaft and the shield tunnel.

2. The method for connecting vertical shafts in a power shield tunnel as described in claim 1, characterized in that, The steel pipe segment (2) includes a steel pipe segment body (21) and a steel pipe segment body (22). The steel pipe segment body (21) is bolted to the concrete pipe segment (1). The steel pipe segment body (21) and the steel pipe segment body (22) are bolted together. The steel pipe segment body (22) forms an open section.

3. The method for connecting vertical shafts in a power shield tunnel as described in claim 2, characterized in that, The demolition and opening section forms a connection between the vertical shaft and the shield tunnel, including: Using small tools, the bolts (5) between the main body (21) and the segment (22) of the steel pipe section are manually removed, the segment (22) of the steel pipe section is removed, forming a connection between the shaft and the shield tunnel, and steel bars are inserted into the cavity of the main body (21) of the steel pipe section and filled with concrete.

4. The method for connecting vertical shafts in a power shield tunnel as described in claim 2, characterized in that, After the grouting pipe (4) is pre-embedded in the lower part of the shaft and grouting is performed, the following is included: A waterproof layer is wrapped around the side wall of the initial support concrete retaining wall (3) of the shaft, and the vertical steel bars inside the initial support concrete retaining wall (3) of the shaft are welded to the main body of the steel pipe segment (21).

5. The method for connecting vertical shafts in a power shield tunnel as described in claim 2, characterized in that, The steel pipe segment (22) is located in the middle of the steel pipe segment body (21).

6. The method for connecting vertical shafts in a power shield tunnel as described in claim 1, characterized in that, The steel pipe segment (2) and the concrete pipe segment (1) have the same diameter and the same thickness.

7. The method for connecting vertical shafts in a power shield tunnel as described in claim 1, characterized in that, The process of excavating the shaft downwards at the corresponding preset power shaft location until the connection point between the shaft and the shield tunnel is reached, and simultaneously constructing the initial support concrete retaining wall of the shaft (3), includes: Excavate downwards from the ground to 0.5-1m above the concrete segment (1) of the corresponding steel pipe segment (2), and simultaneously construct the initial support concrete retaining wall (3) of the shaft. The thickness of the initial support concrete retaining wall (3) of the shaft is greater than or equal to 150 mm.

8. The method for connecting vertical shafts in a power shield tunnel as described in claim 1, characterized in that, Before the initial support concrete retaining wall (3) of the construction shaft, the following are also included: Temporary supports (6) are installed at the positions corresponding to the steel segments (2) inside the shield tunnel. The temporary supports (6) include interconnected circumferential steel frames (61) and longitudinal connecting steel (62). The circumferential steel frames (61) are fitted with the inner wall of the concrete segments (1) with a clearance. The circumferential steel frames (61) and the concrete segments (1) are wedged together by steel wedges. The longitudinal connecting steel (62) is supported inside the circumferential steel frames (61) and fixed to the circumferential steel frames (61).

9. The method for connecting vertical shafts in a power shield tunnel as described in claim 1, characterized in that, After the grouting pipe (4) is pre-embedded in the lower part of the shaft and grouting is performed, the following is also included: A water-stop steel plate is installed on the inner side of the initial support concrete wall (3) of the shaft, and the water-stop steel plate is welded to the steel pipe segment (2) on both sides.

10. The method for connecting vertical shafts in a power shield tunnel as described in claim 1, characterized in that, The method for connecting the vertical shaft of the power shield tunnel also includes: The horizontal displacement, vertical settlement and joint opening of the concrete segment (1) are monitored in real time. If the horizontal displacement, vertical settlement or joint opening of the concrete segment (1) exceeds the preset threshold, construction is suspended and reinforcement measures are taken.

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