A multi-hole combined platform based on mechanical method of hall-platform separation and its construction method

Abstract

This invention provides a multi-tunnel combined platform based on mechanical platform and concourse separation and its construction method. It includes two shield tunnels, designated as an up-going tunnel and a down-going tunnel, respectively located on both sides of the platform level and connected to a central passage via cross passages. The platform level is connected to the concourse level via escalators and inclined passages. A heat exhaust duct is installed above the shield tunnels. This invention reduces the amount of underground excavation work, lowers construction risks, and largely eliminates the need for traffic diversion and pipeline relocation. It avoids the impact of station construction on surface traffic, underground pipelines, and surrounding buildings, and reduces pollution such as dust, vibration, and noise. The two platforms are directly connected, ensuring a single, clear passenger flow path from the concourse to the platform, good visibility, and high user comfort. The platform construction method of this invention, combined with the highly mechanized inter-station shield tunneling method, increases the mechanization rate of station construction, reduces dependence on geological conditions and labor, and minimizes the impact on the surface environment.

Description

Technical Field

[0001] This invention relates to the field of underground transportation engineering technology, specifically to a multi-hole combined platform based on mechanical method of separating the platform and the construction method thereof. Background Technology

[0002] While we have methods to combine the safety and efficiency of shield tunneling with widening excavation to address the many contradictions and challenges of building subway stations in complex urban environments, this method is not suitable for all engineering conditions. For example, the island platform subway station space type combining shield tunneling and widening excavation presents challenges from a construction perspective due to the large amount of segment removal and widening work, the large overall span of the platform space, and the need for favorable geological conditions. For geological environments with significant burial depth, a relatively defined and stable bedrock overburden thickness, and underdeveloped bedrock fissure water, this method can be used to construct platform spaces with large passenger capacity and comfortable functionality. Unfortunately, geological conditions often vary greatly. For complex strata with significant bedrock surface undulations and uneven weathering, excessive widening excavation and overall span can significantly increase engineering risks, or necessitate expensive engineering measures to mitigate these risks. In such cases, if we still require platform spaces with large passenger capacity and comfort, how can we combine this with the highly mechanized inter-section shield tunneling method to maximize the mechanization rate of station construction, reduce reliance on geological conditions and manual labor, and minimize the impact on the ground environment? Our research yielded a new cross-sectional design that can both meet the spatial functional requirements of island platform levels and significantly reduce the strict dependence on geological conditions. Summary of the Invention

[0003] This invention provides a multi-port combined platform based on mechanical separation of the platform and the construction method thereof. The multi-port combined platform uses two shield tunnels as the driving area and passenger boarding / alighting space. A central passage is established between the two shield tunnels as the station platform traffic and waiting area. The central passage is connected to the shield tunnels at the corresponding positions of the platform doors by a small cross passage, serving as a passenger boarding / alighting passage. A concourse level is set in the space above the platform level, and an escalator and inclined passage connect the concourse level and the platform level. Entrances / exits and ground ventilation shafts are also provided. The combination of the entrances / exits and ground ventilation shafts, the concourse level, and the platform level forms a complete subway station.

[0004] The driving area and passenger boarding / alighting space include two shield tunnels, one of which is set as the upward track and the other as the downward track. The upward and downward tracks are respectively located on both sides of the platform level and are connected to the central passage through cross passages. The platform level is connected to the concourse level through escalator inclined passages. A heat exhaust duct is provided above the shield tunnel.

[0005] Preferably, rock pillars are left between the transverse passages.

[0006] Preferably, the multi-hole combined platform based on mechanical method of platform separation is constructed in the rock layer below the soil layer, and the platform layer is covered by the surrounding rock overburden layer.

[0007] Preferably, a construction method for a multi-port combined platform based on mechanical platform separation includes the following steps:

[0008] S1. First, construct two shield tunnels using the shield tunneling method to serve as the driving area and passenger boarding / alighting space.

[0009] S2. Construct a central passage between the two shield tunnels using the cut-and-cover method or the pipe jacking method to serve as the station platform traffic and waiting area. Construct a small cross passage to connect the shield tunnel with the cut-and-cover or pipe jacking tunnel. Layout and process design of the station's public area and equipment room within the platform space.

[0010] S3. Construct the station hall using open excavation or pipe jacking methods and install escalators and inclined passageways to connect the station hall level and the platform level;

[0011] S4. Construct entrances and ventilation shafts at ground level using open-cut or shield tunneling methods.

[0012] Preferably, in step S2, rock pillars are left between the transverse channels, and the stress state of the rock pillars is related to the length of the transverse channels and the properties of the surrounding rock.

[0013] Preferably, step S2 includes the following specific steps:

[0014] S21. First, the strength-stress ratio of the rock column needs to be analyzed based on the geological conditions. The geometric parameters of the rock column are then determined based on the strength-stress ratio to ensure that the rock column is in a stable state. This ensures that the surrounding rock pressure during construction is mainly borne by the rock column and the tunnel support structure, while also alleviating the stress concentration on the shield-retained segments or jacking pipe sections.

[0015] S22. Simplify the soil layer above the surrounding rock overburden as a load, without considering the stress release of the overburden surrounding rock, and then analyze the upper limit of the internal force of the support structure under the action of ground pressure through a physical model of the tunnel support structure and the surrounding rock bearing the load together. Combine the internal force conditions with the internal force of the tunnel support structure under hydrostatic pressure to determine the upper limit of the internal force of the support structure.

[0016] S23. The shield tunnel segments and jacking pipe segments to be retained shall be made of reinforced concrete, while the shield tunnel segments and jacking pipe segments to be removed shall be made of glass fiber reinforced concrete.

[0017] S24. The central passage will be constructed using either the cut-and-cover method or the pipe jacking method. If the cut-and-cover method is used, the cut-and-cover tunnel will employ composite lining. In the tunnel support structure, the initial support will use a high-performance steel fiber shotcrete structure, and the secondary lining will use a reinforced concrete structure. A waterproof membrane will be used between the initial support and the secondary lining. Prestressed anchor bolts will be installed as needed based on the geological sketch. Utilizing the space of the shield tunnel and in conjunction with the location of the cross passage, multi-point transverse mechanized cut-and-cover excavation will be adopted to form multiple cut-and-cover tunnel working faces. Rapid cut-and-cover tunnel cyclic construction will be achieved along the longitudinal direction of the station, thereby avoiding the need to set up temporary construction shafts and construction passages on the ground.

[0018] S25. The cross passage is consolidated with the shield tunnel segments or the jacking pipe sections by a post-cast reinforced concrete ring beam, and consolidated with the secondary lining of the mined tunnel by pre-reserved steel bars.

[0019] S26. After the secondary lining or pipe jacking construction of the mined tunnel is completed, the construction of the remaining cross passages corresponding to the moving doors of the subway trains shall be completed in sequence.

[0020] Preferably, between steps S24 and S25, after the secondary lining or jacking of the mined tunnel is completed, and the shield tunnel segments and jacking pipe sections are supported by steel structure trusses in the shield tunnel and jacking pipe corresponding to the cross passage position, the shield tunnel segments and jacking pipe sections are removed and the remaining cross passage construction is completed. The cross passage is consolidated with the shield tunnel segments or jacking pipe sections by a post-cast reinforced concrete ring frame beam, and consolidated with the secondary lining of the mined tunnel by reserved steel bars.

[0021] Preferably, the steps between step S1 and step S2 include the following: determining the width modulus of shield tunnel segments and jacking pipe sections based on the train's movable door spacing modulus and width, so that the width of the transverse passage connecting the shield tunnel and the mined tunnel or jacking pipe matches the width modulus of the dismantled shield tunnel segments and dismantled jacking pipe sections; and determining the span and line spacing of the central passage based on the width of the side platform and the layout of stairs and escalators.

[0022] The present invention relates to a multi-hole combined platform based on mechanical platform separation and its construction method. It adopts a construction method that combines highly mechanized shield tunneling with mechanized underground excavation to complete the construction of a platform layer with large passenger capacity and comfortable space. Combined with the highly mechanized section shield tunneling method, it improves the mechanization rate of station construction, reduces dependence on geological conditions and labor, and reduces the impact on the ground environment.

[0023] Multi-port combined platforms based on mechanical methods for separating the concourse and platform can effectively meet the station's technological and functional requirements, while reducing the cross-section of the tunnel and lowering construction risks. Except for auxiliary structures, they basically do not require traffic diversion or pipeline relocation, avoiding the impact of the main station construction on surface traffic, underground pipelines, and surrounding buildings, and reducing pollution such as dust, vibration, and noise, resulting in significant social and environmental benefits. The two platforms are directly connected, and the passenger flow path from the concourse to the platform is unique and the destination is clear. The platform and concourse spaces are continuous and have good visibility, resulting in high user comfort. The subway stations used include, but are not limited to, island platforms. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the multi-hole combined platform with connecting passages on the platform level, based on the mechanical method of separating the platform and hall in this invention.

[0025] Figure 2 This is a schematic diagram of the structure of the multi-hole combined platform with mechanical separation of the platform and the platform, based on the present invention, at the point where there is no connecting passage on the platform level;

[0026] Figure 3 This is a schematic cross-sectional view of the platform level of the multi-hole combined platform based on the mechanical method of separating the platform and the station hall according to the present invention.

[0027] Figure 4 This is a schematic diagram of the platform layout of the multi-hole combined platform based on the mechanical method of separating the platform and the hall, according to the present invention.

[0028] In the diagram: 1. First shield tunnel; 2. Second shield tunnel; 3. Upward track; 4. Downward track; 5. Central passage; 61. First transverse passage; 62. Second transverse passage; 7. Station hall level; 8. Escalator; 9. Exhaust ventilation duct; 10. Train access door; 11. Rock pillar; 12. Initial support; 13. Rock surface line; 14. Surrounding rock overburden; 15. Soil layer; 16. Secondary lining; 17. Shield tunnel segment retained; 18. Shield tunnel segment removed; 19. Prestressed anchor bolt; 20. Concrete ring frame beam. Detailed Implementation

[0029] 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.

[0030] The multi-cavity combined platform of this invention, based on mechanical platform separation, is constructed in the rock strata below the rock surface line 13, and is covered by a surrounding rock overburden layer 14. (See attached diagram for reference.) Figure 1 This invention relates to a schematic diagram and appendix of a multi-hole combined platform with connecting passageways on the platform level, based on a mechanical method for separating the platform and hall. Figure 3 This invention presents a cross-sectional view of a multi-port combined platform based on mechanical platform separation. The platform utilizes two shield tunnels (a first shield tunnel 1 and a second shield tunnel 2) as the train operating area and passenger boarding / alighting space. A central passageway 5 is established between the first and second shield tunnels 1 and 2 as the station platform traffic and waiting area. A concourse level 7 is constructed above the platform, with escalators and inclined walkways connecting the concourse level 7 and the platform level. Small cross passageways connect the central passageway 5 and the shield tunnels at corresponding positions on the platform screen doors. In this embodiment, the first cross passageway 61 and the second cross passageway 62 on both sides of the central passageway 5 serve as passenger boarding / alighting passages. Entrances / exits and ground-level ventilation shafts are also included. The combination of the entrances / exits, ground-level ventilation shafts, concourse level 7, and platform level forms a complete subway station.

[0031] The first shield tunnel 1, which is the driving area and passenger boarding and alighting space, is equipped with an upward track 3, and the second shield tunnel 2 is equipped with a downward track 4. The upward track 3 and the downward track 4 are respectively located on both sides of the platform level. The platform level is equipped with a connecting escalator 8. The first shield tunnel 1 and the second shield tunnel 2 are equipped with a heat exhaust duct 9. Rock pillars 11 are left between the first cross passage 61 and the second cross passage 62.

[0032] This invention provides a method for constructing a multi-hole combined platform based on mechanical platform separation, comprising the following steps:

[0033] S1. First, construct two shield tunnels using the shield tunneling method to serve as the driving area and passenger boarding and alighting space; the two shield tunnels are the first shield tunnel 1 and the second shield tunnel 2. The first shield tunnel 1 is equipped with an upward track 3, and the second shield tunnel is equipped with a downward track 4. The upward track 3 and the downward track 4 are respectively located on both sides of the platform level.

[0034] S2. The central passage 5 between the two shield tunnels is constructed using the cut-and-cover method or the pipe jacking method as the station platform traffic and waiting area. Small cross passages are constructed to connect the shield tunnels with the cut-and-cover or pipe jacking tunnels. The small cross passages are the first cross passage 61 and the second cross passage 62 on both sides of the central passage 5. The layout and process design of the station's public area and equipment room are carried out within the platform space.

[0035] S3. The station hall is constructed by open excavation or pipe jacking and escalators 8 are installed to connect the station hall level 7 and the platform level.

[0036] S4. Construct entrances and ventilation shafts at ground level using open-cut or shield tunneling methods.

[0037] Between steps S1 and S2, the following steps are performed: Based on the spacing modulus and width of the train movable door 10, determine the width modulus of the shield tunnel segments and the jacking pipe sections, so that the width of the cross passage connecting the shield tunnel and the mined tunnel or the jacking pipe matches the width modulus of the shield demolition segment 18 and the width modulus of the demolished jacking pipe section; and determine the span and line spacing of the central passage based on the width of the side platform and the layout of the stairs and escalators 8.

[0038] In step S2, rock pillars 11 are left between the transverse channels. The stress state of the rock pillars is related to the length of the transverse channels and the properties of the surrounding rock. The shorter the length of the transverse channels, the greater the slenderness ratio of the rock pillars, and the rock pillars are under high pressure and strong shear stress.

[0039] In step S2, the specific steps are as follows:

[0040] S21. First, the strength-stress ratio of the rock column needs to be analyzed based on the geological conditions. The geometric parameters of the rock column 11 are determined based on the strength-stress ratio to ensure that the rock column 11 is in a stable state. This ensures that the surrounding rock pressure during construction is mainly borne by the rock column 11 and the tunnel support structure, while also alleviating the stress concentration on the retained shield segment 17 or the retained jacking pipe section.

[0041] S22. Simplify the soil layer above the surrounding rock cover layer 14 into a load, without considering the stress release of the surrounding rock cover layer. Then, analyze the upper limit of the internal force of the support structure under the pressure of the stratum (soil layer 15) through the physical model of the tunnel support structure and the surrounding rock bearing the load. Combine the internal force conditions with the tunnel support structure under the hydrostatic pressure condition to determine the upper limit of the internal force of the support structure.

[0042] S23, Shield tunnel segment 17, The retained jacking pipe segment adopts a reinforced concrete structure, and shield tunnel segment 18, The demolished jacking pipe segment adopts a glass fiber reinforced concrete structure.

[0043] S24. The central passage shall be constructed using either the cut-and-cover method or the pipe jacking method. If the cut-and-cover method is used for the construction of the central passage: the cut-and-cover tunnel shall use composite lining, the initial support 12 shall use high-performance steel fiber shotcrete structure, the secondary lining 16 shall use reinforced concrete structure, and a waterproof membrane shall be used between the initial support 12 and the secondary lining 16. Prestressed anchor bolts 19 shall be installed as needed according to the geological sketch. Utilizing the space of the shield tunnel and in combination with the location of the transverse passage, multi-point transverse mechanized cut-and-cover excavation shall be adopted to form multiple cut-and-cover tunnel working faces. Then, rapid cut-and-cover tunnel cyclic construction shall be achieved along the longitudinal direction of the station, thereby avoiding the need to set up temporary construction shafts and construction passages on the ground.

[0044] Between steps S24 and S25, the secondary lining or jacking of the mined tunnel is completed. After the shield tunnel and jacking pipe sections are supported by steel structure trusses in the shield tunnel and jacking pipe corresponding to the cross passage position, the shield tunnel segments and jacking pipe sections are removed and the remaining cross passage construction is completed. The cross passage is consolidated with the shield tunnel segments or jacking pipe sections by a post-cast reinforced concrete ring frame beam, and consolidated with the secondary lining of the mined tunnel by a reserved steel bar.

[0045] S25, the cross passage is consolidated with the shield tunnel segment 17 or the jacking pipe section through the post-cast reinforced concrete ring beam 20, and is consolidated with the secondary lining of the mined tunnel 16 through the reserved steel bars.

[0046] S26. After the secondary lining or pipe jacking of the mined tunnel is completed, the construction of the remaining cross passages corresponding to the subway train's movable door 10 shall be completed in sequence.

[0047] This invention relates to a multi-cavity combined platform based on mechanized platform and hall separation and its construction method. It employs a construction approach combining highly mechanized shield tunneling and mechanized cut-and-cover methods to construct platform levels with high passenger capacity and comfortable spaces. Combined with the highly mechanized inter-section shield tunneling method, this increases the mechanization rate of station construction, reduces dependence on geological conditions and labor, and minimizes the impact on the ground environment.

[0048] Multi-port combined platforms based on mechanical methods for separating the concourse and platform can effectively meet the station's technological and functional requirements, while reducing the cross-section of the tunnel and lowering construction risks. Except for auxiliary structures, they basically do not require traffic diversion or pipeline relocation, avoiding the impact of the main station construction on surface traffic, underground pipelines, and surrounding buildings, and reducing pollution such as dust, vibration, and noise, resulting in significant social and environmental benefits. The two platforms are directly connected, and the passenger flow path from the concourse to the platform is unique and the destination is clear. The platform and concourse spaces are continuous and have good visibility, resulting in high user comfort. The subway stations used include, but are not limited to, island platforms.

[0049] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A construction method for a multi-hole combined platform based on mechanical method of hall-platform separation, characterized in that, Two shield tunnels serve as the driving area and passenger boarding and alighting space. A central passage is set up between the two shield tunnels as the station platform traffic and waiting area. The central passage is connected to the shield tunnels by a small cross passage at the corresponding position of the platform door, serving as a passenger boarding and alighting passage. A concourse level is set up in the space above the platform level, and an escalator inclined passage connects the concourse level and the platform level. Entrances and exits and ground ventilation shafts are set up. The three spaces of the entrances and exits, ground ventilation shafts, concourse level and platform level are combined to form a complete subway station. The train operation area and passenger boarding / alighting space include two shield tunnels, one of which serves as the upward track and the other as the downward track. The upward and downward tracks are respectively located on both sides of the platform level and connected to the central passage via cross passages. The platform level is connected to the concourse level via escalators and inclined passages. A heat exhaust duct is provided above the shield tunnel. The multi-hole combined platform based on mechanical method of separating the platform and concourse is constructed in the rock strata below the soil layer, and the platform level is covered by a surrounding rock overburden layer. The construction method of multi-port combined platforms based on mechanical method of separating the hall and platform includes the following steps: S1. First, construct two shield tunnels using the shield tunneling method to serve as the driving area and passenger boarding / alighting space. S2. Construct a central passage between the two shield tunnels using the cut-and-cover method or the pipe jacking method to serve as the station platform traffic and waiting area. Construct a small cross passage to connect the shield tunnels with the central passage formed by the cut-and-cover method or the pipe jacking method. Design the layout and process of the station's public areas and equipment rooms within the platform space. In step S2, rock pillars are left between the transverse channels, and the stress state of the rock pillars is related to the length of the transverse channels and the properties of the surrounding rock. In step S2, the specific steps are as follows: S21. First, the strength-stress ratio of the rock column needs to be analyzed based on the geological conditions. The geometric parameters of the rock column are determined based on the strength-stress ratio to ensure that the rock column is in a stable state. This ensures that the surrounding rock pressure during construction is mainly borne by the rock column and the tunnel support structure, while also alleviating the stress concentration on the shield-retained segments or jacking pipe sections. S22. Simplify the soil layer above the surrounding rock overburden as a load, without considering the stress release of the overburden surrounding rock, and then analyze the upper limit of the internal force of the support structure under the action of the stratum pressure through the physical model of the tunnel support structure and the surrounding rock bearing the load, and combine the internal force working conditions with the internal force of the tunnel support structure under the hydrostatic pressure condition to determine the upper limit of the internal force of the support structure. S23. The shield tunnel segments and jacking pipe sections to be retained are made of reinforced concrete, while the shield tunnel segments and jacking pipe sections to be demolished are made of glass fiber reinforced concrete. S24. The middle passage is constructed using either the cut-and-cover method or the pipe jacking method. If the cut-and-cover method is used, the cut-and-cover tunnel adopts a composite lining. In the tunnel support structure, the initial support adopts a high-performance steel fiber shotcrete structure, and the secondary lining adopts a reinforced concrete structure. A waterproof membrane is used between the initial support and the secondary lining. Prestressed anchors are set as needed according to the geological sketch. Utilizing the space of the shield tunnel and combined with the location of the cross passage, multi-point transverse mechanized cut-and-cover excavation is adopted to form multiple cut-and-cover tunnel working faces. Rapid cut-and-cover tunnel cyclic construction is achieved along the longitudinal direction of the station, thereby avoiding the need to set up temporary construction shafts and construction passages on the ground. S25. The cross passage is consolidated with the shield tunnel segment or the jacking pipe segment through a post-cast reinforced concrete ring beam, and is consolidated with the secondary lining of the mined tunnel through reserved steel bars. S26. After the secondary lining or pipe jacking construction of the mined tunnel is completed, the construction of the remaining cross passages corresponding to the moving doors of the subway trains shall be completed in sequence. S3. Construct the station hall using open excavation or pipe jacking methods and install escalators and inclined passageways to connect the station hall level and the platform level; S4. Construct entrances and ventilation shafts at ground level using open-cut or shield tunneling methods.

2. The construction method of the multi-hole combined platform based on mechanical method platform separation according to claim 1, between steps S24 and S25, after the secondary lining or pipe jacking of the mined tunnel is completed, and the shield tunnel segments or pipe jacking sections are supported by steel structure trusses in the shield tunnel or pipe jacking section corresponding to the position of the cross passage, the shield tunnel segments or pipe jacking sections are removed and the remaining cross passage construction is completed. The cross passage is fixed to the shield tunnel segments or pipe jacking sections by post-cast reinforced concrete ring frame beams, and fixed to the secondary lining of the mined tunnel by reserved steel bars.

3. The construction method of multi-hole combined platform based on mechanical platform separation according to claim 1, wherein the following steps are included between step S1 and step S2: determining the width module of shield tunnel segments or jacking pipe sections according to the train door spacing module and width, so that the width of the cross passage connecting the shield tunnel and the central passage formed by the cut-and-cover method or pipe jacking method matches the width module of the shield tunnel segments or jacking pipe sections to be dismantled; and determining the span and line spacing of the central passage according to the side platform width and the staircase and escalator layout.

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