An underground space structure and construction method

Abstract

This invention discloses an underground space structure and construction method, solving the problems of existing pipe jacking methods for underground structure construction, which require cutting steel pipe sections, resulting in complex construction processes, large on-site workload, and high construction risks. The underground space structure of this invention includes a hollow closed support structure. The inner cavity of the hollow closed support structure is equipped with support reinforcements and filled with concrete. The hollow closed support structure includes at least one initial pipe section, multiple standard pipe sections, and at least one subsequent pipe section, formed sequentially during construction. The initial pipe section overlaps and interlocks with adjacent standard pipe sections, between two adjacent standard pipe sections, and between the subsequent pipe section and adjacent standard pipe sections. A waterproof structure is constructed at the overlap and interlocking points. This invention reduces site occupation when using peripheral segmentation, while achieving high mechanized construction efficiency, eliminating the need for segment cutting, improving material utilization, reducing on-site work, increasing construction efficiency, and better ensuring construction quality.

Description

Technical Field

[0001] This invention relates to the field of underground construction technology, and in particular to a pipe jacking method for underground structures. Background Technology

[0002] With urban development, the construction of large-section underground structures using the cut-and-cover method faces challenges such as limited space and significant risks. The new pipe-jacking method for underground structures typically involves driving circular steel pipes horizontally along the outer contour of the underground structure. The pipe sections are connected by interlocking mechanisms to form an outer barrier. After reinforcing the soil between the pipe sections, the steel pipe segments are cut and welded together, requiring additional support structures. Reinforcing steel is then tied inside the pipe sections, followed by concrete pouring. Once the required strength is achieved, the internal soil is excavated. However, existing technologies require extensive soil reinforcement, and cutting the steel pipe segments disturbs the soil. The entire process carries risks of water and sand inrush, and the work procedures are complex, with limited working space, making it difficult to guarantee construction quality and progress.

[0003] In recent years, various improvements and measures have emerged for the new pipe jacking method. For example, the bundled pipe jacking structure and its construction method in application number 202010560298.7 improves the load-bearing capacity of the structure by setting prestressed steel bars; however, the gaps between the pipe jacking structures are difficult to clean due to the presence of soil and sand, and the concrete is not easy to pour densely. The pipe jacking structure and its construction method in application number 202210677944.7 installs push plates on the sidewalls of the joints to ensure the cleanliness of the gaps; however, it generates significant resistance during the jacking process, and the push plates are difficult to remove after completion. The pipe-jacking construction method described in authorization announcement number CN107190775B proposes that combining multiple steel pipes into a pipe-jacking configuration and simultaneously jacking them can improve construction accuracy. The pipe-jacking segment construction method described in authorization announcement number CN109736814B involves layering the pipe jacking and then cutting it into sections to reduce the impact on structural strength. However, both of these methods currently require extensive soil reinforcement, followed by structural demolition of the steel pipe sections already jacked into the soil, and then welding connecting plates and sealing steel plates. The construction process is complex, and there are significant construction risks during the steel pipe cutting process. Therefore, it is necessary to design a pipe-jacking structure and construction method that is simple in construction technology and structurally reliable. Summary of the Invention

[0004] To address the shortcomings of the aforementioned background technology, this invention proposes an underground space structure and construction method, which solves the problems of the existing pipe jacking method for constructing underground structures, which requires cutting steel pipe sections, has a complex construction process, a large amount of on-site work, and high construction risks.

[0005] The technical solution of the present invention is implemented as follows: an underground space structure includes a hollow closed support structure, the inner cavity of which is provided with support reinforcement and filled with concrete; the hollow closed support structure includes at least one preliminary pipe section, multiple standard pipe sections and at least one subsequent pipe section formed in sequence according to the construction, and the preliminary pipe section overlaps and interlocks with the adjacent standard pipe section, between two adjacent standard pipe sections and between the subsequent pipe section and the adjacent standard pipe section.

[0006] Further optimization involves adding a waterproof structure to the overlapping joints; the preceding pipe sections, standard pipe sections, and subsequent pipe sections are all multi-circle composite pipe sections. The structural units are divided into multi-circle composite structures, ensuring no blind spots during equipment excavation. The different composite structures used in the structural units according to the jacking sequence allow for simultaneous jacking by multiple pieces of equipment.

[0007] Further preferably, the preceding pipe section, the standard pipe section, and the following pipe section all include a middle steel structure shell, and at least two side steel structure shells are symmetrically connected to both sides of the middle steel structure shell. Inner support members are provided at intervals at the intersection of the middle steel structure shell and the side steel structure shells, and interlocking openings are provided on the outer side of the side steel structure shells; thus realizing the interlocking and overlapping joint between two adjacent pipe sections.

[0008] Further preferably, the interlocking joints on the two side steel structure shells on both sides of the pilot pipe section are provided with spaced-apart side support members, which are inwardly convex arc-shaped steel structure members; when the pilot pipe section is constructed using the pipe jacking method, a machinable concrete structure is constructed between the side support members and the tunnel wall.

[0009] Further preferably, the standard pipe section has spaced-apart side supports at the interlocking joint on one side of the steel structure shell, and the side supports are inwardly convex arc-shaped steel structures; when the standard pipe section is constructed using the pipe jacking method, a machinable concrete structure is constructed between the side supports and the tunnel wall; a detachable closed temporary steel plate is provided at the interlocking joint on the other side of the steel structure shell, and the closed temporary steel plate is an outwardly convex arc-shaped steel structure.

[0010] Further preferably, a pre-embedded grouting pipe is provided at the intersection of the side support and the side steel structure shell. After the jacking construction of each unit is completed, grouting is used to stop water leakage and reinforce the overlapping positions.

[0011] Further preferably, the two side steel structure shells on both sides of the rear pipe section can be detachably provided with closed temporary steel plates, which are outwardly convex arc-shaped steel structural components.

[0012] In a further preferred embodiment, the closed temporary steel plate is provided with docking grooves at both ends, which are docked with the side steel structure shell and connected by bolts. The closed temporary steel plate is removed before the hollow closed support structure is poured with concrete.

[0013] Further preferably, the support reinforcement includes reinforcing bars, which include pre-set reinforcing bars pre-installed in the intermediate steel structure shell and connecting reinforcing bars used to connect the pre-set reinforcing bars after the preceding pipe sections, standard pipe sections and subsequent pipe sections form a hollow closed support structure.

[0014] A construction method for the aforementioned underground space structure includes the following steps: S1: The pipe section combination form is reasonably divided according to the size, shape and form of the underground structure; and the pipe sections are produced according to the pipe section combination. The pipe sections are divided into the first pipe section, the standard pipe section and the last pipe section according to the jacking sequence; soil discharge channels are reserved on both sides of the first pipe section, the standard pipe section and the last pipe section.

[0015] S2: Based on the construction conditions, at least one preliminary pipe section is constructed using the pipe jacking method. During the construction of the preliminary pipe section, a machinable concrete structure is constructed between the side support of the preliminary pipe section and the tunnel wall to prevent groundwater and soil from entering the preliminary pipe section from both sides.

[0016] S3: Standard pipe sections are constructed simultaneously on both sides of the pilot pipe section. During the jacking process of the pipe jacking machine, the machinable concrete structure of the pilot pipe section is cut off and the standard pipe section is constructed at that location. When there is no groundwater in the excavated stratum, the standard pipe sections are spliced ​​without closed temporary steel plates. At this time, the interlocking joint used to install the closed temporary steel plates is interlocked with the side support of the pilot pipe section. When encountering a high groundwater content, the standard pipe sections are spliced ​​without closed temporary steel plates. At this time, the closed temporary steel plates of the standard pipe sections are close to the side support of the pilot pipe section, and the standard pipe sections and the pilot pipe sections form an interlocking interlocking joint. A machinable concrete structure is constructed between the side support of the standard pipe section and the tunnel wall to prevent groundwater and soil from entering the standard pipe section on that side.

[0017] S4: Continue to construct new standard pipe sections on the side support of the standard pipe section. During the jacking process of the pipe jacking machine, cut off the machinable concrete structure of the standard pipe section and construct a new standard pipe section at that location. Repeat this process until all standard pipe sections are constructed.

[0018] S5: A subsequent pipe section is constructed between two standard pipe sections. During the jacking process of the pipe jacking machine constructing the subsequent pipe section, the machinable concrete structure of the standard pipe section is cut off and the subsequent pipe section is constructed at that location. The closed temporary steel plate of the subsequent pipe section is attached to the side support of the standard pipe section, and the subsequent pipe section and the standard pipe section form an interlocking and overlapping joint.

[0019] S6: Local grouting and water-stopping are carried out at the overlapping joint through the grouting pipes embedded in the pipe section to form a complete waterproof structure. Then, the closed temporary steel plate is removed, the residual concrete at the overlapping joint is chiseled away, and the adjacent pipe sections are welded together to strengthen the sealing and water-stopping, forming an internally connected hollow closed support structure.

[0020] S7: Connect and tie the pre-embedded steel bars in the hollow enclosed support structure with connecting steel bars, and then pour concrete into the hollow enclosed support structure to complete the construction of the underground space structure.

[0021] The tunneling unit incorporates a cuttable section, and after each structural unit is jacked up, an effective structural overlap is formed. The sidewalls are pre-designed as a grid structure, eliminating the need for segment cutting and significantly reducing the amount of welding connections. Using multi-circle jacking equipment, in addition to the soil exit channels required for jacking, some internal structures have pre-installed reinforcing steel, reducing work in confined spaces and improving construction efficiency.

[0022] The beneficial effects of this invention are as follows: This invention divides the underground space structure into different units, adopts mechanized construction, and the unit adopts a combination structure of steel structure and concrete. At the same time, the steel structure is equipped with permanent structure and temporary support structure, and some permanent steel bars are set in the pipe section in advance. The structural connection between each unit is more reliable. The construction process does not require large-scale grouting, cutting of steel pipe segments, and welding volume is greatly reduced. It can effectively improve the efficiency, quality and safety of underground space construction using the pipe jacking method.

[0023] The pipe sections adopt a steel-concrete composite structure, with each section overlapping the others. The overlapping section of the first jacking section uses a concrete structure, which is then removed by the construction equipment used for the subsequent jacking sections. The remaining sections use a steel structure, with sealed top, bottom, and outer surfaces. The internal support structure uses spaced steel plates, ensuring sufficient support strength while avoiding cutting the steel plates during construction and providing enough space for rebar installation. Each unit consists of several circles. The multi-circle structure allows for mechanized excavation without blind spots. The multi-circle combination equipment has soil discharge pipes inside the two side sections, and the rebar structure can be pre-installed in the middle pipe, reducing the amount of work required in confined spaces.

[0024] Compared with existing technologies, the structural form and construction method proposed in this invention solve the problems of existing technologies that require large-scale soil reinforcement and grouting for water stoppage when using the new pipe jacking method, as well as the need for segment cutting and welding, and the need to carry out a large amount of construction work in the narrow space of the steel pipe. Therefore, this invention can reduce site occupation when dividing the perimeter into blocks, while achieving high efficiency of mechanized construction, eliminating the need for segment cutting, improving material utilization, reducing on-site work, improving construction efficiency, and better ensuring construction quality. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a cross-sectional view of the underground structure of the present invention.

[0027] Figure 2 This is a cross-sectional view of the pilot pipe section.

[0028] Figure 3 This is a cross-sectional view of a standard pipe section.

[0029] Figure 4 This is a cross-sectional view of the subsequent pipe section.

[0030] Figure 5 This is a cross-sectional view after the jacking is completed.

[0031] Figure 6 This is a cross-sectional view after the concrete has been poured.

[0032] Figure 7 This is a schematic diagram of an alternative implementation scheme in Example 4. Detailed Implementation

[0033] 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.

[0034] like Figure 1 As shown in Embodiment 1, an underground space structure includes a hollow closed support structure. The inner cavity of the hollow closed support structure is equipped with support reinforcements and filled with concrete to form a stable underground support structure. The key feature of this invention is that the hollow closed support structure includes at least one initial pipe section 1, multiple standard pipe sections 2, and at least one subsequent pipe section 3, formed according to the construction sequence. The initial pipe section 1 is interlocked with adjacent standard pipe sections 2, between two adjacent standard pipe sections 2, and between the subsequent pipe section 3 and adjacent standard pipe sections 2. Because the pipe sections are divided according to the construction sequence, one or more initial pipe sections 1, standard pipe sections 2, and subsequent pipe sections 3 can be constructed simultaneously in their respective construction stages, improving construction efficiency. Furthermore, the interlocking joints between adjacent pipe sections eliminate the need for segment cutting and significantly reduce the amount of welding connections.

[0035] As a preferred option, a waterproof structure is constructed at the overlapping joint to provide a sealing and waterproofing effect. If the excavated stratum is dry or has low permeability, a waterproof structure may not be necessary. The preceding pipe section 1, standard pipe section 2, and subsequent pipe section 3 are all multi-circle composite pipe sections. The pipe section structural units are divided into multi-circle composite structures, improving construction efficiency. This structural division eliminates blind spots during equipment excavation. The pipe section structural units utilize different combination structures depending on the jacking sequence. For example, multiple preceding pipe sections can be constructed simultaneously, followed by multiple standard pipe sections, and finally multiple subsequent pipe sections; alternatively, one preceding pipe section can be constructed first, followed by multiple simultaneous constructions of two standard pipe sections, and finally, one subsequent pipe section. Therefore, this invention, employing the above structural division, ultimately enables simultaneous jacking by multiple pieces of equipment, significantly improving construction efficiency.

[0036] Example 2, an underground space structure, is further optimized based on Example 1. The preceding pipe section 1, standard pipe section 2, and subsequent pipe section 3 all include a central steel structure shell 2-1. The central steel structure shell 2-1 is a partial shell of a circular steel structure, serving to support the soil and prevent soil and water intrusion into the pipe section. At least two side steel structure shells 2-7 are symmetrically connected to both sides of the central steel structure shell 2-1. The side steel structure shells are fixed to the central structure shell in an intersecting connection to form an integrated multi-circular steel structure. The number of side steel structure shells can be two or more, connected sequentially to both sides of the central steel structure shell 2-1 in the same manner. This example uses two side steel structure shells for illustration. Internal support members 2-2 are spaced apart at the intersection of the central steel structure shell 2-1 and the side steel structure shells 2-7. The internal support members 2-2 are support steel plates or reinforcing bars installed inside the pipe section, spaced apart. The intervals allow reinforcing bars to pass through and facilitate the flow of concrete during pouring, eliminating the need for steel structure cutting compared to traditional construction processes. The outer side of the side steel structure shell 2-7 is provided with an interlocking opening; the purpose of the interlocking opening is to achieve stable interlocking between two adjacent pipe sections.

[0037] like Figure 2As shown in this embodiment, the interlocking joints of the two side steel structure shells 2-7 on both sides of the pilot pipe section 1 are provided with spaced-apart side supports 2-8. The side supports 2-8 are support steel plates or reinforcing bars installed inside the pipe section, spaced apart, with reinforcing bars passing through the gaps, facilitating the flow of concrete between the two pipe sections during pouring. The side supports 2-8 are convex arc-shaped steel structures to accommodate the cutting section of the circular jacking cutterhead. When the pilot pipe section 1 is constructed using the jacking method, a machinable concrete structure 2-3 is constructed between the side supports 2-8 and the tunnel wall. The machinable concrete structure 2-3 is located at the overlap position with the standard pipe section and can be removed by the jacking machine cutterhead. The machinable concrete structure 2-3 is formed simultaneously during the construction of the pilot pipe section and can be removed later by the subsequent jacking cutterhead, providing overlap space for the overlap with the standard pipe section. Partial machinable concrete is provided on both sides of the pilot pipe section.

[0038] like Figure 3 As shown in this embodiment, at the interlocking joint of one side steel structure shell 2-7 of the standard pipe section 2, there are spaced-apart side support members 2-8. The side support members 2-8 are support steel plates or reinforcing bars installed inside the pipe section, spaced apart, with reinforcing bars passing through the gaps, which facilitates the flow of concrete between the two pipe sections during the pouring process. The side support members 2-8 are inwardly convex arc-shaped steel structures to adapt to the cutting section of the circular jacking cutterhead. When constructing the standard pipe section 2 using the pipe jacking method, a machinable concrete structure 2-3 is constructed between the side support members 2-8 and the tunnel wall, which is similar to the structure of the preceding pipe section; this machinable concrete structure 2-3 is located at the position where it overlaps with the subsequent pipe section or a new standard pipe section, and can be broken by the jacking machine cutterhead. At the interlocking joint of the other side steel structure shell 2-7 of the standard pipe section 2, there is a detachable closed temporary steel plate 2-6, which is an outwardly convex arc-shaped steel structure. The enclosed temporary steel plate 2-6 is a temporary sealing steel plate that ensures structural sealing during jacking and prevents groundwater and soil from entering. After jacking is completed, the temporary sealing steel plate is connected to the side steel structure shell with bolts. After grouting reinforcement, the temporary sealing steel plate can be removed. The enclosed temporary steel plate 2-6 is suitable for situations with high groundwater content and a high risk of leakage. If there is no groundwater, an open structure can be used, and the temporary sealing steel plate is not required. One side of the standard pipe section is concrete, and the other side is steel structure.

[0039] Pre-embedded grouting pipes 2-5 are installed at the intersection of the side support member 2-8 and the side steel structure shell 2-7 in the pilot pipe section and the standard pipe section. After the tunnel excavation is completed, the pre-embedded grouting pipes 2-5 can be used to grout and reinforce the overlapping parts of each pipe section unit to prevent water leakage.

[0040] like Figure 4As shown in this embodiment, closed temporary steel plates 2-6 are detachably installed at the interlocking joints on the two side steel structure shells 2-7 on both sides of the rear pipe section 3. The closed temporary steel plates 2-6 are outwardly convex arc-shaped steel structural members. Both sides of the rear pipe section are steel structures. Preferably, the closed temporary steel plates 2-6 have butt grooves at both ends, which are connected to the side steel structure shells 2-7 by bolts. The closed temporary steel plates 2-6 are removed before the hollow closed support structure is poured with concrete. The closed temporary steel plates 2-6 are temporary closed steel plates, which can ensure the structure is sealed during the jacking process and prevent groundwater and soil from entering. After the jacking is completed, the temporary closed steel plates are connected to the steel shell structure by bolts. After grouting reinforcement, the temporary closed steel plates can be removed. The closed temporary steel plates are suitable for situations with high groundwater content and high risk of leakage. If there is no groundwater, an open structure can be used, and temporary closed steel plates are not required.

[0041] like Figure 5 As shown, the support reinforcement in this embodiment includes steel bars 2-4. The steel bars 2-4 include pre-set steel bars pre-installed within the intermediate steel structure shell 2-1 and connecting steel bars used to connect the pre-set steel bars after the preceding pipe section 1, standard pipe section 2, and subsequent pipe section 3 form a hollow closed support structure. In other words, during construction, soil is removed from the steel structures on both sides of the multi-circle combined pipe section, and some steel bars can be pre-installed in the intermediate steel structure to reduce the amount of work in the confined underground space and to better ensure construction quality. After all pipe sections are constructed and a hollow closed support structure is formed, the pre-set steel bars are connected into a ring using connecting steel bars to improve the stability of the support structure.

[0042] Each pipe section adopts a steel structure or a steel-concrete composite structure. The pipe sections are constructed underground using the pipe jacking method, and after jacking, the sections overlap. The steel-concrete composite structure utilizes mechanical methods to remove the concrete portions of the previously constructed units. The overlapping of the structural units eliminates the need for cutting the steel pipe sections and significantly reduces welding work. It also eliminates the need for extensive soil grouting reinforcement, reducing construction steps and effectively improving efficiency. Furthermore, the multi-circle pipe jacking construction process, through multi-circle combinations, increases construction speed and optimizes soil removal methods. Reinforcing bars can be pre-installed within some pipe sections, reducing the amount of work in confined spaces and further enhancing construction efficiency.

[0043] The underground space structure of this invention consists of different structural units, divided into preliminary pipe sections, standard pipe sections, and subsequent pipe sections according to the jacking sequence of each structural unit. The pipe sections adopt a steel-concrete composite structure, with each pipe section overlapping the others. The overlapping portion of the preliminary jacking pipe section uses a concrete structure, which is removed by the construction equipment of the subsequent jacking pipe section. The remaining portion uses a steel structure, with sealed top, bottom, and outer surfaces. The internal support structure uses spaced steel plates, ensuring sufficient support strength while avoiding cutting steel plates during construction and providing sufficient space for rebar installation. Each unit consists of several circles. The multi-circle structure allows for mechanized excavation without blind spots. The multi-circle combination equipment has soil discharge pipes inside the pipe sections on both sides, and the rebar structure can be pre-installed in the middle pipe, reducing the workload in confined spaces.

[0044] Example 3, a construction method for an underground space structure as described in Example 2, the steps are as follows: S1: According to the size, shape and form of the underground structure, the pipe section combination form is reasonably divided; and the pipe sections are produced according to the pipe section combination. The pipe sections are divided into the first pipe section, the standard pipe section and the last pipe section according to the jacking sequence; the first pipe section, the standard pipe section and the last pipe section are reserved on both sides for the discharge of excavated soil.

[0045] S2: Depending on the construction conditions, at least one preliminary pipe section is constructed using the pipe jacking method. During the construction of the preliminary pipe section, a machinable concrete structure 2-3 is constructed between the side supports 2-8 of the preliminary pipe section and the tunnel wall to prevent groundwater and soil from entering the preliminary pipe section. When constructing one preliminary pipe section first, two standard pipe sections can be constructed simultaneously multiple times, and finally, the subsequent pipe section is constructed. Alternatively, depending on the construction conditions, two preliminary pipe sections can be constructed first, followed by multiple simultaneous constructions of four standard pipe sections, and finally, the subsequent pipe section is constructed. This embodiment uses the construction of one preliminary pipe section as an example for explanation.

[0046] S3: Two standard pipe sections are simultaneously constructed on both sides of the pilot pipe section. During the jacking process of the pipe jacking machine constructing the standard pipe section, the machinable concrete structure 2-3 of the pilot pipe section is cut off and the standard pipe section is constructed at that location. When there is no groundwater in the excavated stratum, the standard pipe sections are spliced ​​without the closed temporary steel plate 2-6. At this time, the interlocking joint used to install the closed temporary steel plate 2-6 is interlocked with the side support 2-8 of the pilot pipe section. When encountering a high groundwater content, the standard pipe sections are spliced ​​without the closed temporary steel plate 2-6. At this time, the closed temporary steel plate 2-6 of the standard pipe section is tightly attached to the side support 2-8 of the pilot pipe section, and the standard pipe section and the pilot pipe section form an interlocking interlocking joint. A machinable concrete structure 2-3 is constructed between the side support 2-8 of the standard pipe section and the tunnel wall to prevent groundwater and soil from entering the standard pipe section on that side.

[0047] S4: Continue to construct new standard pipe sections on the side support 2-8 of the standard pipe section. During the jacking process of the pipe jacking machine, the machinable concrete structure 2-3 of the standard pipe section is cut off and a new standard pipe section is constructed at that location. Repeat this process until all standard pipe sections are constructed. At this point, the machinable concrete structure 2-3 of the last two standard pipe sections corresponds to each other.

[0048] S5: A subsequent pipe section is constructed between two standard pipe sections. During the jacking process of the pipe jacking machine constructing the subsequent pipe section, the machinable concrete structure 2-3 of the two standard pipe sections is cut off and the subsequent pipe section is constructed at that location. The closed temporary steel plate 2-6 of the subsequent pipe section is attached to the side support 2-8 of the standard pipe section, and the subsequent pipe section and the standard pipe section form an interlocking and overlapping joint.

[0049] S6: Local grouting and water-stopping are carried out at the overlapping joint through the grouting pipes pre-embedded in the pipe section to form a complete waterproof structure. Then, the closed temporary steel plate 2-6 is removed, the residual concrete at the overlapping joint is chiseled away, and the adjacent pipe sections are welded together to strengthen the sealing and water-stopping, forming an internally connected hollow closed support structure.

[0050] S7: Connect and tie the pre-embedded steel bars within the hollow enclosed support structure using connecting steel bars, then pour concrete into the hollow enclosed support structure to complete the construction of the underground space structure. After the underground space structure reaches the strength requirements, excavate the soil within the enclosure of the underground space structure to complete the remaining construction work; ensure construction safety. Figure 6 As shown.

[0051] According to the present invention, the underground space structure is divided into different units and mechanized construction is adopted. The unit adopts a combination structure of steel structure and concrete. At the same time, the steel structure is equipped with permanent structure and temporary support structure. Some permanent steel bars are set in the pipe sections in advance, making the structural connection between each unit more reliable. The construction process does not require large-scale grouting, cutting of steel pipe segments, and welding volume is greatly reduced, which can effectively improve the efficiency, quality and safety of underground space construction using the pipe jacking method.

[0052] Example 4, as Figure 7As shown, this embodiment provides an alternative implementation method, in which the pipe section structure is divided into a preliminary unit 3-1 and a subsequent unit 3-2. A multi-circle jacking method is used for construction. Temporary standard pipe sections 3-3 are installed inside the steel structures on both sides of the preliminary unit. Rollers can be installed on the inner walls of the steel structures on both sides of the preliminary unit, and then the temporary standard pipe sections 3-3 are fixed inside the preliminary unit 3-1 using rollers 3-5. During the jacking process of the subsequent unit 3-2, the temporary standard pipe sections 3-3 are simultaneously jacked in and replaced, and they are connected sequentially to form a hollow closed support structure. Then, internal steel bars are installed inside the hollow closed support structure and concrete is poured; finally, an underground space support structure is formed. The structural joints of the above embodiment are prone to water leakage, requiring the installation of sealed waterproof joints. Moreover, if the steel structures on both sides of the preliminary unit use sealed cavity components, segment cutting is required, making the construction process slightly complicated; however, it can be used as an alternative implementation method under certain working conditions.

[0053] 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. An underground space structure, characterized in that: The hollow closed support structure includes a hollow closed support structure with a support reinforcement component in the inner cavity and concrete poured in; the hollow closed support structure includes at least one preliminary pipe section (1), multiple standard pipe sections (2) and at least one subsequent pipe section (3) formed according to the construction sequence, with the preliminary pipe section (1) overlapping and interlocking with the adjacent standard pipe section (2), between two adjacent standard pipe sections (2) and between the subsequent pipe section (3) and the adjacent standard pipe section (2); The preceding pipe section (1), the standard pipe section (2) and the following pipe section (3) all include a middle steel structure shell (2-1). At least two side steel structure shells (2-7) are symmetrically connected on both sides of the middle steel structure shell (2-1). An inner support member (2-2) is provided at intervals at the intersection of the middle steel structure shell (2-1) and the side steel structure shell (2-7). An interlocking opening is provided on the outer side of the side steel structure shell (2-7). The two side steel structure shells (2-7) on both sides of the pilot pipe section (1) are provided with spaced side support members (2-8), and the side support members (2-8) are convex arc-shaped steel structure members; when the pilot pipe section (1) is constructed by the pipe jacking method, a machinable concrete structure (2-3) is constructed between the side support members (2-8) and the tunnel wall. The standard pipe section (2) has a side support (2-8) at the interlocking joint on one side steel structure shell (2-7). The side support (2-8) is an inwardly convex arc-shaped steel structure. When the standard pipe section (2) is constructed by the pipe jacking method, a machinable concrete structure (2-3) is constructed between the side support (2-8) and the tunnel wall. The other side steel structure shell (2-7) has a detachable closed temporary steel plate (2-6) at the interlocking joint. The closed temporary steel plate (2-6) is an outwardly convex arc-shaped steel structure.

2. The underground space structure according to claim 1, characterized in that: The overlapping joints are equipped with waterproof structures; the preceding pipe section (1), the standard pipe section (2) and the following pipe section (3) are all multi-circle combined pipe sections.

3. The underground space structure according to claim 1 or 2, characterized in that: A pre-embedded grouting pipe (2-5) is provided at the intersection of the side support member (2-8) and the side steel structure shell (2-7).

4. The underground space structure according to claim 3, characterized in that: The two side steel structure shells (2-7) on both sides of the rear pipe section (3) can be detachably equipped with closed temporary steel plates (2-6), which are convex arc-shaped steel structure components.

5. The underground space structure according to claim 4, characterized in that: The closed temporary steel plate (2-6) has docking grooves at both ends. The docking grooves are docked with the side steel structure shell (2-7) and connected by bolts. The closed temporary steel plate (2-6) is removed before the hollow closed support structure is poured with concrete.

6. The underground space structure according to claim 4 or 5, characterized in that: The support reinforcement includes steel bars (2-4), which include pre-set steel bars in the intermediate steel structure shell (2-1) and connecting steel bars used to connect the pre-set steel bars after the preceding pipe section (1), standard pipe section (2) and subsequent pipe section (3) form a hollow closed support structure.

7. A construction method for an underground space structure as described in claim 6, characterized in that: The steps are as follows: S1: According to the size, shape and form of the underground structure, the pipe section combination form is reasonably divided; and the pipe section is produced according to the pipe section combination. The pipe section is divided into the first pipe section, the standard pipe section and the last pipe section according to the jacking sequence; the soil discharge channel is reserved on both sides of the first pipe section, the standard pipe section and the last pipe section. S2: Based on the construction conditions, at least one preliminary pipe section is constructed using the pipe jacking method. During the construction of the preliminary pipe section, a machinable concrete structure (2-3) is constructed between the side support (2-8) of the preliminary pipe section and the tunnel wall to prevent groundwater and soil from entering the preliminary pipe section from both sides. S3: Standard pipe sections are constructed simultaneously on both sides of the pilot pipe section. During the jacking process of the pipe jacking machine, the machinable concrete structure (2-3) of the pilot pipe section is cut off and the standard pipe section is constructed at that location. When there is no groundwater in the excavated stratum, the standard pipe sections are spliced ​​without the closed temporary steel plate (2-6). At this time, the interlocking joint used to install the closed temporary steel plate (2-6) is interlocked with the side support (2-8) of the pilot pipe section. When encountering a high groundwater content, the standard pipe sections are spliced ​​without the closed temporary steel plate (2-6). At this time, the closed temporary steel plate (2-6) of the standard pipe section is close to the side support (2-8) of the pilot pipe section, and the standard pipe section and the pilot pipe section form an interlocking interlocking joint. A machinable concrete structure (2-3) is constructed between the side support (2-8) of the standard pipe section and the tunnel wall to prevent groundwater and soil from entering the standard pipe section on this side. S4: Continue to construct new standard pipe sections on the side support (2-8) of the standard pipe section. During the jacking process of the pipe jacking machine, cut off the machinable concrete structure (2-3) of the standard pipe section and construct a new standard pipe section at that location. Repeat this process until all standard pipe sections are constructed. S5: A subsequent pipe section is constructed between two standard pipe sections. During the jacking process of the pipe jacking machine constructing the subsequent pipe section, the machinable concrete structure (2-3) of the standard pipe section is cut off and the subsequent pipe section is constructed at that location. The closed temporary steel plate (2-6) of the subsequent pipe section is attached to the side support (2-8) of the standard pipe section, and the subsequent pipe section and the standard pipe section form an interlocking and overlapping joint. S6: Local grouting and water-stopping are carried out at the overlapping joint through the grouting pipes embedded in the pipe section to form a complete waterproof structure. Then, the closed temporary steel plate (2-6) is removed, the residual concrete at the overlapping joint is chiseled away, and the adjacent pipe sections are welded together to strengthen the sealing and water-stopping, forming an internally connected hollow closed support structure. S7: Connect and tie the pre-embedded steel bars in the hollow enclosed support structure with connecting steel bars, and then pour concrete into the hollow enclosed support structure to complete the construction of the underground space structure.

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