Underground space structure and construction method

Abstract

The invention discloses an underground space structure and a construction method. The problems that in the prior art, steel pipe joints need to be cut when an underground structure is constructed through a pipe-roofing method, the construction technology is complex, the field operation amount is large, and the construction risk is high are solved. The underground space structure comprises a hollow closed supporting structure, a supporting reinforcing piece is arranged in an inner cavity of the hollow closed supporting structure, and concrete is poured in the inner cavity of the hollow closed supporting structure; the hollow closed supporting structure comprises at least one preceding pipe joint, a plurality of standard pipe joints and at least one following pipe joint which are formed according to the construction sequence, the preceding pipe joint and the adjacent standard pipe joint, every two adjacent standard pipe joints and the following pipe joint and the adjacent standard pipe joint are in lap joint and meshed, and waterproof structures are constructed at the lap joint and meshed positions. Under the condition that peripheral partitioning is carried out, the occupied field can be reduced, meanwhile, the mechanical construction efficiency is high, segment cutting is not needed, the material utilization rate is increased, meanwhile, field operation is reduced, the construction efficiency is improved, and the construction quality is better guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of underground construction, in particular to an underground structure using a pipe curtain method. Background Art

[0002] With the development of urban construction, the construction of large-section structures in underground space using the dark excavation method faces the problems of small space and huge risks. The new pipe curtain method for constructing underground structures generally adopts the method of driving round steel pipes horizontally along the outer contour of the underground structure. The pipe curtains are connected by locks to form an outer barrier. After the soil between the pipe curtains is reinforced, the steel pipe sections are cut and welded, and the supporting structure needs to be supplemented. Then, steel bars are tied in the pipe sections, and concrete is poured. After reaching the strength requirements, the internal soil is excavated. The existing technology requires large-scale soil reinforcement, and cutting steel pipe segments disturbs the soil. There is a certain risk of water and sand gushing in the whole process. In addition, the operation procedures are complicated, the construction space is small, and the construction quality and progress are difficult to guarantee.

[0003] In recent years, different improvement plans and measures have emerged for the new pipe-roof method. For example, the bundled pipe-roof structure and its construction method with application number 202010560298.7 improves the bearing capacity of the structure by setting prestressed steel bars, but the gaps between the pipe-roof structures are difficult to clean and the concrete is not easy to pour densely. The pipe-roof structure and its construction method with application number 202210677944.7 set a push plate on the side wall of the joint to ensure the cleanliness of the gap, but it generates greater resistance during the jacking process and is difficult to remove the push plate after completion. The pipe row and pipe curtain construction method with the authorization announcement number CN107190775B proposes that multiple steel pipes are combined into a pipe row and pushed forward at the same time to improve the construction accuracy. The construction method of the pipe curtain section with the authorization announcement number CN109736814 B divides the pipe curtain into layers and then cuts and constructs in sections to reduce the impact on the structural strength. However, both methods currently require large-scale reinforcement of the soil, and then structurally break the steel pipe sections that have been pushed into the soil, and then weld the connecting plates and sealing steel plates. The construction process is complicated, and there is a great construction risk during the steel pipe cutting process. Therefore, it is necessary to design a pipe curtain structure and construction method with simple construction process and reliable structure. Summary of the invention

[0004] In view of the deficiencies in the above-mentioned background technology, the present invention proposes an underground space structure and a construction method, which solves the problems in the prior art of underground structure construction using the pipe curtain method, which requires cutting of steel pipe sections, has complex construction processes, large on-site workload 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 the hollow closed support structure is provided with a support reinforcement and poured with concrete; the hollow closed support structure includes at least one leading pipe section, multiple standard pipe sections and at least one subsequent pipe section formed in the order of construction, and the leading pipe section and the adjacent standard pipe section, the two adjacent standard pipe sections and the subsequent pipe section and the adjacent standard pipe section are overlapped and interlocked.

[0006] It is further preferred that a waterproof structure is applied at the overlapped joint; the preceding pipe section, the standard pipe section and the following pipe section are all multi-circle combined pipe sections. The structural units are divided, and each structural unit is a multi-circle combined structure. There is no blind spot when the equipment is used for excavation. The structural units adopt different combined structural forms according to the order of jacking, which can realize the simultaneous jacking of multiple equipment.

[0007] Further preferably, the leading pipe joint, standard pipe joint and trailing pipe joint all include an intermediate steel structure shell, at least two side steel structure shells are symmetrically connected on both sides of the intermediate steel structure shell, an internal support is provided at the intersection of the intermediate steel structure shell and the side steel structure shell, and a bite opening is provided on the outer side surface of the side steel structure shell, so as to realize the bite overlap between two adjacent pipe joints.

[0008] It is further preferred that the engaging openings on the two side steel structure shells on both sides of the advance pipe section are provided with spaced-apart side support members, which are inwardly convex arc-shaped steel structure members; when the advance pipe section is constructed by the jacking method, a machinable concrete structure is constructed between the side support members and the cave wall.

[0009] Further preferably, the bite mouth on one side steel structure shell of the standard pipe joint is provided with spaced side supports, which are inwardly convex arc-shaped steel structure members; when the standard pipe joint is constructed by the jacking method, a machinable concrete structure is constructed between the side supports and the cave wall; the bite mouth on the other side steel structure shell is removably provided with a closed temporary steel plate, which is an outwardly convex arc-shaped steel structure member.

[0010] Preferably, a pre-buried grouting pipe is provided at the intersection of the side support member and the side steel structure shell. After the top pipe construction of each unit is completed, grouting is used to stop water and reinforce the overlap position.

[0011] Further preferably, closed temporary steel plates are detachably provided at the engaging openings on the two side steel structure shells on both sides of the rear pipe section, and the closed temporary steel plates are outwardly convex arc-shaped steel structure parts.

[0012] Further preferably, both ends of the closed temporary steel plate are provided with docking grooves, which are docked with the side steel structure shell and connected by bolts, and the closed temporary steel plate is removed before pouring concrete for the hollow closed supporting structure.

[0013] Further preferably, the support reinforcement includes steel bars, and the steel bars include preset steel bars pre-set in the middle steel structure shell and connecting steel bars used to connect the preset steel bars after the leading pipe segments, standard pipe segments and subsequent pipe segments form a hollow closed support structure.

[0014] A construction method for an underground space structure, comprising the following steps: S1: reasonably dividing the pipe segment combination form according to the size, shape and form of the underground structure; producing the pipe segments according to the pipe segment combination situation, and dividing the pipe segments into leading pipe segments, standard pipe segments and trailing pipe segments according to the jacking sequence; soil discharge channels are reserved on both sides of the leading pipe segments, standard pipe segments and trailing pipe segments; S2: According to the construction conditions, at least one advance pipe section is constructed by the pipe jacking method. During the construction of the advance pipe section, a machinable concrete structure is constructed between the side support members of the advance pipe section and the tunnel wall to prevent underground water and soil on both sides from entering the advance pipe section; S3: Standard pipe sections are constructed synchronously on both sides of the leading pipe section. During the jacking process of the pipe jacking machine for constructing the standard pipe section, the cuttable concrete structure of the leading pipe section is cut off and the standard pipe section is constructed there. When there is no groundwater in the excavated stratum, the standard pipe section is spliced ​​without a closed temporary steel plate. At this time, the bite mouth used to install the closed temporary steel plate is overlapped with the side support of the leading pipe section; when the groundwater content is high, the standard pipe section is spliced ​​without a closed temporary steel plate. At this time, the closed temporary steel plate of the standard pipe section is close to the side support of the leading pipe section, and the standard pipe section and the leading pipe section form an intersecting bite overlap; a cuttable concrete structure is constructed between the side support of the standard pipe section and the cave wall to prevent the groundwater and soil on this side from entering the standard pipe section; S4: Continue to construct new standard pipe segments on the side of the side support of the standard pipe segment. During the jacking process of the pipe jacking machine constructing the standard pipe segment, the cuttable concrete structure of the standard pipe segment is cut off and a new standard pipe segment is constructed there. This is repeated until all standard pipe segments are constructed. S5: Install the rear pipe section between the two standard pipe sections. During the jacking process of the pipe jacking machine for installing the rear pipe section, the cuttable concrete structure of the standard pipe section is cut off and the rear pipe section is installed there. The closed temporary steel plate of the rear pipe section is close to the side support of the standard pipe section, and the rear pipe section and the standard pipe section form an intersecting overlap; S6: Use the grouting pipe pre-buried in the pipe segment to perform local grouting and water-stopping at the lap joints to form a complete waterproof structure, then remove the closed temporary steel plate, chisel out the remaining concrete at the lap joints, and weld the adjacent pipe segments to strengthen the sealing and water-stopping to form a hollow closed support structure with internal communication; S7: The embedded steel bars in the hollow closed supporting structure are connected and tied by connecting steel bars, and then concrete is poured into the hollow closed supporting structure to complete the construction of the underground space structure.

[0015] A cuttable part is set in the excavation unit, and effective structural overlap is formed after each structural unit is jacked. The side wall is preset as a grid structure, which does not require segment cutting and greatly reduces the amount of welding connections. Multi-dome jacking equipment is used for construction. Under the condition of multi-dome jacking, in addition to the excavation channel required for jacking, steel bars are pre-installed inside some structures, which can reduce operations in limited spaces and improve construction efficiency.

[0016] The beneficial effects of the present invention are as follows: the present invention divides the underground space structure into different units, adopts mechanized construction, the units adopt a combination structure of steel structure and concrete, and at the same time, the steel structure is provided with a permanent structure and a temporary support structure, and some permanent steel bars are arranged in the pipe sections in advance, so that the structural connection between the units is more reliable, and the construction process does not require large-scale grouting, does not require cutting of steel pipe segments, and the amount of welding is also greatly reduced, which can effectively improve the efficiency, quality and safety of underground space construction by the pipe curtain method.

[0017] The pipe section adopts a steel-concrete composite structure, and each pipe section structure overlaps each other. The first jacking pipe section adopts a concrete structure in the overlapping part, which is broken by the construction equipment of the jacking pipe section. The rest of the steel structure adopts a sealed structure on the upper and lower top surfaces and the outer side surfaces. The internal support structure is set with steel plates at intervals. Under the requirement of ensuring sufficient support strength, it can avoid cutting steel plates during construction and meet the installation space of steel bars. Each unit is composed of several circles. The multi-circle structure adopts mechanized excavation construction without blind spots. The multi-circle combination equipment sets soil discharge pipes in the pipe sections on both sides, and the steel bar structure can be installed in the middle pipe in advance, which can reduce the workload in a small space.

[0018] Compared with the prior art, the structural type and construction method proposed in the present invention solve the problems in the prior art that the new pipe curtain method construction requires large-scale soil reinforcement grouting and water stopping, and requires pipe segment cutting and welding, and a large amount of construction work needs to be carried out in the narrow space of the steel pipe. Therefore, the present invention can reduce site occupancy when performing peripheral block division. At the same time, mechanized construction has high efficiency, no pipe segment cutting is required, and material utilization is improved. At the same time, on-site operations are reduced, construction efficiency is improved, and construction quality is better guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0020] Figure 1 It is a cross-sectional view of the underground structure of the present invention.

[0021] Figure 2 This is a cross-sectional view of the advance pipe segment.

[0022] Figure 3 This is the cross-sectional view of a standard pipe joint.

[0023] Figure 4 This is a cross-sectional view of the posterior tube segment.

[0024] Figure 5 This is the cross-sectional view after the jacking is completed.

[0025] Figure 6 This is the cross-section view after concrete pouring.

[0026] Figure 7 Schematic diagram of an alternative implementation scheme in Example 4. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] like Figure 1 As shown, in Example 1, an underground space structure includes a hollow closed support structure, the inner cavity of the hollow closed support structure is provided with a support reinforcement and poured with concrete to form a stable underground support structure. The focus of the present invention is that the hollow closed support structure includes at least one leading pipe segment 1, a plurality of standard pipe segments 2 and at least one trailing pipe segment 3 formed in the order of construction, and the leading pipe segment 1 and the adjacent standard pipe segment 2, between two adjacent standard pipe segments 2, and between the trailing pipe segment 3 and the adjacent standard pipe segment 2 are overlapped and interlocked. Because the pipe segments are divided according to the order of construction, one or more of the leading pipe segment 1, the standard pipe segment 2 and the trailing pipe segment 3 can be simultaneously applied in the corresponding construction stage, thereby improving construction efficiency. In addition, the bite overlap between adjacent pipe segments does not require pipe segment cutting, and the amount of welding connections is greatly reduced.

[0029] As a preferred solution, a waterproof structure is constructed at the overlapped joints to provide a sealing and waterproof effect. When the excavated stratum is water-free or has a relatively low permeability, a waterproof structure may not be required. The leading pipe segment 1, the standard pipe segment 2, and the trailing pipe segment 3 are all multi-circle combined pipe segments. The pipe segment structural units are divided, and each pipe segment structural unit is a multi-circle combined structure to provide one-time construction efficiency. The above structural division can achieve no blind spots when using equipment for excavation. The pipe segment structural units adopt different combined structural forms according to the order of jacking, such as multiple leading pipe segments can be constructed simultaneously, followed by multiple standard pipe segments, and finally multiple trailing pipe segments; or a leading pipe segment can be constructed first, followed by multiple standard pipe segments, and finally a trailing pipe segment. Therefore, the present invention adopts the above structural division, which can ultimately achieve simultaneous jacking of multiple devices and greatly improve construction efficiency.

[0030] Embodiment 2, an underground space structure, based on embodiment 1, is further optimized in this embodiment, wherein the preceding pipe section 1, the standard pipe section 2 and the following pipe section 3 all include an intermediate steel structure shell 2-1, and the intermediate steel structure shell 2-1 is a partial shell of a circular steel structure, which plays a role in supporting the soil and preventing water and soil from invading the pipe section. At least two side steel structure shells 2-7 are symmetrically connected on both sides of the intermediate steel structure shell 2-1; the side steel structure shells are fixed on the intermediate structure shell in an intersecting connection to form an integrated multi-circular steel structure; the number of side steel structure shells can be 2 or more, and they are sequentially connected to both sides of the intermediate steel structure shell 2-1 in the same way. In this embodiment, two side steel structure shells are used as an example for explanation. The intersection of the intermediate steel structure shell 2-1 and the side steel structure shell 2-7 is provided with an inner support 2-2 at intervals, and the inner support 2-2 is a support steel plate or steel bar arranged in the pipe section, which is arranged at intervals, and the steel bar can pass through the intervals and is conducive to the flow of concrete during pouring. Compared with the traditional construction process, there is no need to cut the steel structure. The outer side surface of the side steel structure shell 2-7 is provided with a bite opening; the original intention of setting the bite opening is to achieve a stable bite between two adjacent pipe sections.

[0031] like Figure 2As shown, the side supports 2-8 are arranged at intervals at the bite openings on the two side steel structure shells 2-7 on both sides of the leading pipe section 1 in this embodiment; the side supports 2-8 are support steel plates or steel bars arranged in the pipe section, arranged at intervals, and the steel bars can pass through the intervals and are conducive to the flow between the two pipe sections during the concrete pouring process. The side supports 2-8 are arc-shaped steel structures with inward convexity to adapt to the cutting section of the circular jacking cutter head. When the leading pipe section 1 is constructed by the jacking method, a cuttable concrete structure 2-3 is constructed between the side supports 2-8 and the cave wall. The cuttable concrete structure 2-3 is located at the position of overlapping with the standard pipe section and can be broken by the jacking machine cutter head. The cuttable concrete structure 2-3 is formed synchronously when the leading pipe section is constructed by the jacking section, and can be removed by the subsequent jacking cutter head at a later stage to provide overlapping space for overlapping with the standard pipe section. Part of the cuttable concrete is set on both sides of the leading pipe section.

[0032] like Figure 3 As shown, in this embodiment, the side support 2-8 is arranged at intervals at the bite mouth on one side steel structure shell 2-7 of the standard pipe segment 2. The side support 2-8 is a support steel plate or steel bar arranged in the pipe segment, which is arranged at intervals. The steel bar can pass through the interval and is conducive to the flow between the two pipe segments during the concrete pouring process. The side support 2-8 is an inwardly convex arc-shaped steel structure; it is adapted to the cutting section of the circular jacking cutter. When the standard pipe segment 2 is constructed by the jacking method, a cuttable concrete structure 2-3 is constructed between the side support 2-8 and the cave wall, which is similar to the structure of the preceding pipe segment; the cuttable concrete structure 2-3 is located at the position of overlapping with the subsequent pipe segment or the new standard pipe segment, and can be broken by the jacking machine cutter. A closed temporary steel plate 2-6 is detachably arranged at the bite mouth on the other side steel structure shell 2-7 of the standard pipe segment 2. The closed temporary steel plate 2-6 is an outwardly convex arc-shaped steel structure. The closed temporary steel plate 2-6 is a temporary closed steel plate, which can ensure the structural sealing during the jacking process to prevent the entry of groundwater and soil. After the jacking is completed, the temporary closed steel plate is connected to the side steel structure shell by bolts. After grouting reinforcement, the temporary closed steel plate can be removed. The closed temporary steel plate 2-6 is suitable for situations with high groundwater content and high risk of water leakage. If there is no groundwater, an open structure can be used without setting up a temporary closed steel plate. One side of the standard pipe section is concrete and the other side is steel structure.

[0033] The intersection of the side support 2-8 and the side steel structure shell 2-7 in the advance pipe section and the standard pipe section is provided with a pre-buried grouting pipe 2-5. After the tunnel excavation is completed, the pre-buried grouting pipe 2-5 can be used to grout the overlapped parts of each pipe section unit to prevent water leakage.

[0034] like Figure 4As shown, in this embodiment, the two side steel structure shells 2-7 on both sides of the rear pipe section 3 are provided with a closed temporary steel plate 2-6 at the bite mouth, and the closed temporary steel plate 2-6 is a convex arc steel structure. Both sides of the rear pipe section are steel structures. As a preferred embodiment, the closed temporary steel plate 2-6 is provided with a docking groove at both ends, and the docking groove is 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. The closed temporary steel plate 2-6 is a temporary closed steel plate, which can ensure the structural sealing during the jacking process to prevent the entry of groundwater and soil. After the jacking is completed, the temporary closed steel plate is connected to the steel shell structure by bolts. After grouting reinforcement, the temporary closed steel plate can be removed. The closed temporary steel plate is suitable for situations where the groundwater content is high and the risk of water leakage is high. If there is no groundwater, an open structure can be used and no temporary closed steel plate is set.

[0035] like Figure 5 As shown, the support reinforcement members in this embodiment include steel bars 2-4, and the steel bars 2-4 include preset steel bars pre-set in the middle steel structure shell 2-1 and connecting steel bars used to connect the preset steel bars after the leading pipe segment 1, the standard pipe segment 2 and the trailing pipe segment 3 form a hollow closed support structure. That is to say, during the construction process, soil is discharged from the steel structures on both sides of the multi-circular combined pipe segment, and some steel bars can be installed in the middle steel structure in advance to reduce the workload in the small underground space and make it easier to ensure the construction quality. After all the pipe segments are constructed to form a hollow closed support structure, the preset steel bars are connected into a ring with connecting steel bars to improve the stability of the support structure.

[0036] Each pipe section adopts steel structure or steel-concrete composite structure. Each pipe section adopts the jacking method underground. After the jacking is completed, the pipe sections can be overlapped. The pipe section adopts a steel-concrete composite structure, and the concrete part of the first construction unit is broken by mechanical construction. The structural units constructed before and after overlap each other, so there is no need to cut the steel pipe section structure, and the welding workload is greatly reduced. At the same time, there is no need to grout and reinforce the soil on a large scale, which reduces the construction process and effectively improves the construction efficiency. In addition, the multi-circle jacking construction process is adopted to improve the construction speed through the multi-circle combination, and at the same time optimize the excavation method. The steel bars can be pre-installed in some pipe sections, which reduces the construction workload in a small space and is more conducive to improving the construction efficiency.

[0037] The underground space structure of the present invention is composed of different structural units, which are divided into leading pipe sections, standard pipe sections and trailing pipe sections according to the order of jacking of each structural unit. The pipe sections adopt a steel-concrete composite structure, and each pipe section structure overlaps each other. The jacking pipe section that is jacked first adopts a concrete structure in the overlapping part, which is broken by the construction equipment of the trailing jacking pipe section. The remaining part adopts a steel structure. The upper and lower top surfaces and the outer side surfaces of the steel structure adopt a sealing structure. The internal support structure adopts steel plate intervals. While ensuring sufficient support strength, it can avoid cutting steel plates during construction and meet the installation space of steel bars. Each unit is composed of several circles. The multi-circle structure adopts mechanized excavation construction without blind spots. The multi-circle combination equipment sets soil discharge pipes in the pipe sections on both sides, and the steel bar structure can be installed in the middle pipe in advance, which can reduce the workload in a small space.

[0038] Embodiment 3, a construction method of an underground space structure as described in Embodiment 2, the steps are as follows: S1: Reasonably divide the pipe segment combination forms according to the size, appearance and shape of the underground structure; and produce the pipe segments according to the pipe segment combination situation, and divide the pipe segments into leading pipe segments, standard pipe segments, and trailing pipe segments according to the jacking order; soil discharge channels are reserved on both sides of the leading pipe segments, standard pipe segments, and trailing pipe segments for discharging debris.

[0039] S2: According to the construction conditions, at least one advance pipe section is constructed by the pipe jacking method. During the construction of the advance pipe section, a cuttable concrete structure 2-3 is constructed between the side support 2-8 of the advance pipe section and the cave wall to prevent underground water and soil on both sides from entering the advance pipe section. When a advance pipe section is constructed first, then two standard pipe sections can be constructed simultaneously for multiple times, and then the subsequent pipe section can be constructed. It is also possible to construct two advance pipe sections first according to the working conditions, then four standard pipe sections can be constructed simultaneously for multiple times, and then the subsequent pipe section can be constructed. This embodiment is described by taking the construction of a advance pipe section as an example.

[0040] S3: Two standard pipe sections are constructed synchronously on both sides of the preceding pipe section. During the jacking process of the pipe jacking machine for constructing the standard pipe section, the cuttable concrete structure 2-3 of the preceding pipe section is cut off and the standard pipe section is constructed there. When there is no groundwater in the excavated stratum, the standard pipe section is spliced ​​without the closed temporary steel plate 2-6. At this time, the bite mouth used to install the closed temporary steel plate 2-6 is overlapped with the side support 2-8 of the preceding pipe section; when the groundwater content is high, the standard pipe section is 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 preceding pipe section, and the standard pipe section and the preceding pipe section form an intersecting bite overlap; the cuttable concrete structure 2-3 is constructed between the side support 2-8 of the standard pipe section and the cave wall to prevent groundwater and soil on this side from entering the standard pipe section.

[0041] S4: Continue to construct new standard pipe segments on the side of the side support 2-8 of the standard pipe segment, cut off the cuttable concrete structure 2-3 of the standard pipe segment during the jacking process of the jacking machine for constructing the standard pipe segment, and construct a new standard pipe segment at its location; repeat this process until all standard pipe segments are constructed; at this time, the cuttable concrete structures 2-3 of the last two standard pipe segments correspond.

[0042] S5: A rear pipe joint is constructed between two standard pipe joints. During the jacking process of the pipe jacking machine for constructing the rear pipe joint, the machinable concrete structures 2-3 of the two standard pipe joints are cut off and the rear pipe joint is constructed there. The closed temporary steel plate 2-6 of the rear pipe joint is close to the side support 2-8 of the standard pipe joint, and the rear pipe joint and the standard pipe joint form an intersecting and interlocking overlap.

[0043] S6: Local grouting and water-stopping are performed on the overlapping joints through the grouting pipes pre-buried in the pipe segments to form a complete waterproof structure. Then, the closed temporary steel plates 2-6 are removed, the remaining concrete in the overlapping joints is chiseled out, and the adjacent pipe segments are welded to strengthen the sealing and water-stopping to form a hollow closed support structure that is internally connected.

[0044] S7: Connect and tie the embedded steel bars in the hollow closed support structure through connecting steel bars, and then pour concrete into the hollow closed 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 and complete other construction of the underground space structure; ensure construction safety. Figure 6 shown.

[0045] According to the present invention, the underground space structure is divided into different units and mechanized construction is adopted. The units adopt a combination structure of steel structure and concrete. At the same time, the steel structure is provided with a permanent structure and a temporary support structure. Some permanent steel bars are arranged in the pipe sections in advance. The structural connection between the units is more reliable. The construction process does not require large-scale grouting, cutting of steel pipe segments, and the amount of welding is also greatly reduced, which can effectively improve the efficiency, quality and safety of underground space construction by the pipe curtain method.

[0046] Embodiment 4, as Figure 7As shown, this embodiment provides an alternative implementation method, in which the pipe segment structure is divided into an advance unit 3-1 and a rear unit 3-2, and the multi-dome top pipe method is used for construction. Temporary standard pipe segments 3-3 are set in the steel structures on both sides of the advance unit, and rollers can be set on the inner walls of the steel structures on both sides of the advance unit. Then, the temporary standard pipe segments 3-3 are fixed in the advance unit 3-1 by using rollers 3-5. During the jacking process of the rear unit 3-2, the temporary standard pipe segments 3-3 are replaced by jacking synchronously, and are connected in sequence to form a hollow closed support structure. Then, internal steel bars are installed in the hollow closed support structure and concrete is poured; finally, an underground space support structure is formed. The structural joints of the above-mentioned implementation method are prone to water leakage and require closed waterproof joints. Moreover, if the steel structures on both sides of the advance unit use closed cavity components, pipe segment cutting is required, and the construction process is slightly complicated; however, it can be used as an alternative implementation method under certain working conditions.

[0047] 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 in the protection scope of the present invention.

Claims

1. An underground space structure, characterized in that: The hollow closed support structure comprises a hollow closed support structure, wherein the inner cavity of the hollow closed support structure is provided with a support reinforcement member and poured with concrete; the hollow closed support structure comprises at least one leading pipe section (1), a plurality of standard pipe sections (2) and at least one trailing pipe section (3) formed in the order of construction, wherein the leading pipe section (1) and the adjacent standard pipe section (2), the adjacent two standard pipe sections (2) and the trailing pipe section (3) and the adjacent standard pipe section (2) are overlapped and interlocked.

2. The underground space structure according to claim 1, characterized in that: A waterproof structure is applied at the overlapped joints; 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: The leading pipe section (1), the standard pipe section (2) and the trailing pipe section (3) all include an intermediate steel structure shell (2-1), at least two side steel structure shells (2-7) are symmetrically connected to the two sides of the intermediate steel structure shell (2-1), an inner support member (2-2) is provided at intervals at the intersection of the intermediate steel structure shell (2-1) and the side steel structure shell (2-7), and a bite opening is provided on the outer side surface of the side steel structure shell (2-7).

4. The underground space structure according to claim 3, characterized in that: The engaging openings of the two side steel structure shells (2-7) on both sides of the advance pipe section (1) are provided with spaced-apart side support members (2-8), the side support members (2-8) being inwardly convex arc-shaped steel structure members; when the advance 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 cave wall.

5. The underground space structure according to claim 3, characterized in that: A side support member (2-8) is provided at intervals at the engagement opening on one side steel structure shell (2-7) of the standard pipe section (2), and the side support member (2-8) is an inwardly convex arc-shaped steel structure member; when the standard pipe section (2) is constructed by the pipe jacking method, a cuttable concrete structure (2-3) is constructed between the side support member (2-8) and the cave wall; a closed temporary steel plate (2-6) is detachably provided at the engagement opening on the other side steel structure shell (2-7), and the closed temporary steel plate (2-6) is an outwardly convex arc-shaped steel structure member.

6. The underground space structure according to claim 4 or 5, characterized in that: A pre-buried grouting pipe (2-5) is provided at the intersection of the side support member (2-8) and the side steel structure shell (2-7).

7. The underground space structure according to claim 6, characterized in that: The engaging openings on the two side steel structure shells (2-7) on both sides of the rear pipe joint (3) are both detachably provided with closed temporary steel plates (2-6), which are outwardly convex arc-shaped steel structure parts.

8. The underground space structure according to claim 7, characterized in that: The closed temporary steel plate (2-6) is provided with butt joint grooves at both ends, the butt joint grooves are butt jointed with the side steel structure shell (2-7) and connected via bolts, and the closed temporary steel plate (2-6) is removed before pouring concrete into the hollow closed support structure.

9. The underground space structure according to claim 4, 5, 7 or 8, characterized in that: The support reinforcement member comprises steel bars (2-4), wherein the steel bars (2-4) comprise a preset steel bar member pre-set in the middle steel structure shell (2-1) and a connecting steel bar member used to connect the preset steel bar member after the preceding pipe segment (1), the standard pipe segment (2) and the succeeding pipe segment (3) form a hollow closed support structure.

10. An underground space structure and construction method as claimed in claim 9, characterized in that: The steps are as follows: S1: Reasonably divide the pipe segment combination form according to the size, shape and shape of the underground structure; and produce the pipe segment according to the pipe segment combination situation. The pipe segment is divided into the leading pipe segment, the standard pipe segment and the trailing pipe segment according to the jacking sequence; soil discharge channels are reserved on both sides of the leading pipe segment, the standard pipe segment and the trailing pipe segment; S2: According to the construction conditions, at least one advance pipe segment is constructed by the pipe jacking method. During the construction of the advance pipe segment, a cuttable concrete structure (2-3) is constructed between the side support member (2-8) of the advance pipe segment and the cave wall to prevent underground water and soil on both sides from entering the advance pipe segment; S3: Standard pipe sections are synchronously constructed on both sides of the preceding pipe section. During the jacking process of the pipe jacking machine for constructing the standard pipe section, the cuttable concrete structure (2-3) of the preceding pipe section is cut off and the standard pipe section is constructed there. When there is no groundwater in the excavated stratum, the standard pipe section is spliced ​​without the closed temporary steel plate (2-6). At this time, the bite mouth for installing the closed temporary steel plate (2-6) is overlapped with the side support (2-8) of the preceding pipe section. When the groundwater content is high, the standard pipe section is 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 preceding pipe section, and the standard pipe section and the preceding pipe section form an intersecting overlap. The cuttable concrete structure (2-3) is constructed between the side support (2-8) of the standard pipe section and the cave wall to prevent the groundwater and soil on this side from entering the standard pipe section. S4: Continue to construct a new standard pipe segment on the side of the side support member (2-8) of the standard pipe segment, and during the jacking process of the pipe jacking machine for constructing the standard pipe segment, cut off the cuttable concrete structure (2-3) of the standard pipe segment and construct a new standard pipe segment there; repeat this process until all standard pipe segments are constructed; S5: A rear pipe section is installed between two standard pipe sections. During the jacking process of the pipe jacking machine for installing the rear pipe section, the cuttable concrete structure (2-3) of the standard pipe section is cut off and the rear pipe section is installed there. The closed temporary steel plate (2-6) of the rear pipe section is closely attached to the side support (2-8) of the standard pipe section, and the rear pipe section and the standard pipe section form an intersecting overlap; S6: Local grouting is performed on the overlapping joints through the grouting pipes pre-buried in the pipe segments to form a complete waterproof structure, and then the closed temporary steel plate (2-6) is removed, the remaining concrete in the overlapping joints is chiseled out, and the adjacent pipe segments are welded to strengthen the sealing and waterproofing to form a hollow closed support structure with internal communication; S7: The embedded steel bars in the hollow closed supporting structure are connected and tied by connecting steel bars, and then concrete is poured into the hollow closed supporting structure to complete the construction of the underground space structure.

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