Supporting structure system of existing metro station downward layering and expansion by underground excavation

Abstract

The application discloses a kind of underground excavation expansion support structure system of existing metro station downward storey, comprising: non-closed beam pipe curtain, it is set in the soil below existing metro station, and the side of pipe curtain towards existing metro station is formed with through gap;Connecting structure, including freezing cushion, top beam of reverse construction and water stop reinforcing part, freezing cushion is arranged between pipe curtain and the bottom of existing metro station, top beam of reverse construction is poured in the bottom of existing metro station and is arranged in through gap, top beam of reverse construction connects the inner wall of pipe curtain, water stop reinforcing part is connected to the outer wall of pipe curtain, freezing cushion and the bottom of existing metro station;Pre-support reinforcing body is supported between the opposite two inner walls of pipe curtain.The application solves the problem that existing shield method or mine method is used in the expansion and reconstruction of old station downward storey, and it is difficult to realize platform transfer or the amount of reinforcement is large, construction disturbance is large, construction speed is slow.

Description

Technical Field

[0001] This invention relates to the field of tunnel construction technology, specifically to a support structure system for the underground expansion of an existing subway station by adding a lower level. Background Technology

[0002] With the construction of urban subway projects, many new subway lines currently involve the expansion and renovation of existing stations by adding floors downwards. Currently, subway interchange projects often employ shield tunneling or mining methods for construction. Shield tunneling often presents challenges such as disconnected platform levels in new stations, difficulties in platform transfers, and deep track burial. Mining methods, on the other hand, are characterized by high construction risks, large reinforcement volumes, slow construction speed, and significant disturbance to the superstructure of the existing stations.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, a support structure system for the underground expansion of existing subway stations is provided. This system addresses the problems of difficulty in achieving platform transfers, large reinforcement volumes, significant construction disturbance, and slow construction speed when using existing shield tunneling or mining methods for the expansion and renovation of old stations.

[0005] To achieve the above objectives, a support structure system for the underground expansion of existing subway stations by adding layers downwards is provided, comprising:

[0006] A non-closed bundled tube curtain is installed in the soil below an existing subway station. A through gap is formed on the side of the non-closed bundled tube curtain facing the existing subway station. The through gap is set along the length direction of the non-closed bundled tube curtain.

[0007] The connecting structure includes a freezing pad, a reverse-operation top beam, and a water-stopping reinforcement. The freezing pad is placed between the non-closed bundled tube curtain and the bottom of the existing subway station. The reverse-operation top beam is cast into the bottom of the existing subway station and is located within the through gap. The reverse-operation top beam is connected to the inner wall of the non-closed bundled tube curtain. The water-stopping reinforcement is connected to the outer wall of the non-closed bundled tube curtain, the freezing pad, and the bottom of the existing subway station.

[0008] The pre-supported reinforcement is supported between the two opposing inner walls of the non-closed bundled tube curtain.

[0009] Furthermore, the cross-section of the non-closed bundled tube curtain is rectangular, and the through-hole is located at the top of the non-closed bundled tube curtain.

[0010] Furthermore, there are multiple reverse-operation top beams, which are arranged along the width direction of the non-closed bundled tube curtain, and steel supports connect the multiple reverse-operation top beams.

[0011] Furthermore, the water-stopping reinforcement and the pre-supported reinforcement are prepared using the MJS method.

[0012] Furthermore, the existing subway station has a launching shaft and a receiving shaft on opposite sides, and the two ends of the non-closed bundled tube curtain are respectively connected to the launching shaft and the receiving shaft through shaft joints.

[0013] Furthermore, the inner wall of the non-closed bundled tube curtain is provided with multiple compartmentalized tube curtains, which divide the inner cavity of the non-closed bundled tube curtain into multiple compartments along the width direction of the non-closed bundled tube curtain.

[0014] The beneficial effects of this invention are as follows: the underground expansion support structure system for adding layers to existing subway stations ensures the connectivity of the new station platform, enabling platform transfers. The pipe jacking can be constructed close to the existing station floor slab, eliminating the need for deepening during node track design. Simultaneously, the pipe jacking itself, through prestressed tensioning and manhole joints, forms a relatively rigid semi-enclosed structure, providing support for the soil outside the tunnel. It is independent of geological conditions and can be constructed in any geological stratum. Only pipe sections need to be reinforced upon entering and exiting the tunnel, requiring a relatively small amount of reinforcement. The soil inside the pipe jacking can be excavated in a single compartment, significantly increasing construction speed. Through the non-closed bundled pipe jacking and compartmentalized pipe jacking, the existing station above is supported, effectively reducing disturbance to the old station during the construction of the lower tunnel, exhibiting good geological adaptability and safety.

[0015] The existing subway station underground expansion support structure system of the present invention forms a new type of retaining structure system with the old station through non-closed bundled pipe curtain, which serves as the retaining structure of the underground transfer passage.

[0016] The non-closed bundled pipe jacking system of the underground expansion support structure for adding layers to existing subway stations in this invention is connected to the existing subway station via a connecting structure. This connecting structure employs MJS water-stopping reinforcement and a freezing pad layer to treat the gap between the non-closed bundled pipe jacking and the existing subway station, serving both force transmission and water-stopping functions. Furthermore, a reverse-construction top beam is cast at the bottom of the existing subway station, connecting the pipe jacking to the existing subway station. This reverse-construction top beam is a permanent-temporary combined structure, also acting as a corbel to transmit horizontal and vertical forces, ensuring continuous force transmission with the existing subway station and reducing the stress on the existing subway station's foundation slab. Attached Figure Description

[0017] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0018] Figure 1 This is a schematic diagram of the support structure system for the underground expansion of an existing subway station by adding layers downwards, according to an embodiment of the present invention.

[0019] Figure 2 for Figure 1 The sectional view at EE.

[0020] Figure 3 This is a cross-sectional view of the underground excavation support structure system for adding layers to an existing subway station, according to an embodiment of the present invention.

[0021] Figures 4 to 13 This is a schematic diagram illustrating the construction steps of the underground excavation and expansion support structure system for adding layers to an existing subway station, according to an embodiment of the present invention. Detailed Implementation

[0022] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0024] Reference Figures 1 to 13 As shown, where, Figure 6 for Figure 5 Sectional view at point AA in the diagram. Figure 8 for Figure 7 Sectional view at BB in the middle. Figure 10 for Figure 9 Sectional view at CC in the middle, Figure 11 for Figure 9 The cross-sectional view at DD in the figure shows that the present invention provides a support structure system for the underground expansion of an existing subway station by adding a lower layer, including: a non-closed bundled pipe curtain 1, a connecting structure 2, and a pre-supported reinforcement body 3.

[0025] Among them, the non-closed bundled tube curtain 1 is installed in the soil below the existing subway station 11.

[0026] The cross-section of the non-closed bundled tube curtain 1 is rectangular. A through gap is formed on the side of the non-closed bundled tube curtain 1 facing the existing subway station 11. The through gap is set along the length of the non-closed bundled tube curtain 1. The non-closed bundled tube curtain is U-shaped overall. The through gap is set at the top of the non-closed bundled tube curtain 1.

[0027] In this embodiment, the inner wall of the non-closed bundled tube curtain 1 is provided with multiple compartmentalized tube curtains 6. The multiple compartmentalized tube curtains 6 divide the inner cavity of the non-closed bundled tube curtain 1 into multiple compartments along the width direction of the non-closed bundled tube curtain 1.

[0028] See Figure 1 and Figure 2 As shown, the connecting structure 2 includes a freezing pad 21, a reverse top beam 22, and a water-stopping reinforcement 23.

[0029] Specifically, the frozen cushion layer 21 is placed between the bottom of the non-closed bundled tube curtain 1 and the existing subway station 11. In this embodiment, the frozen cushion layer is formed by freezing the soil between the bottom of the non-closed bundled tube curtain 1 and the existing subway station 11.

[0030] The inverted top beam 22 is cast at the bottom of the existing subway station 11 and is located within the through gap. The inverted top beam 22 is connected to the inner wall of the non-closed bundled tube curtain 1.

[0031] There are multiple reverse-operation top beams 22. These multiple reverse-operation top beams 22 are arranged along the width direction of the non-closed bundled pipe curtain 1. Steel supports 7 connect the multiple reverse-operation top beams 22.

[0032] Among them, the reverse-beam also serves as a corbel, connecting to the non-closed bundled tube curtain 1 or the compartment tube curtain.

[0033] The water-stopping reinforcement 23 is connected to the outer wall of the non-closed bundled pipe curtain 1, the freezing pad layer 21 and the bottom of the existing subway station 11.

[0034] The pre-supported solid 3 is supported between the two opposing inner walls of the non-closed bundle curtain 1.

[0035] As a preferred embodiment, the water-stopping reinforcement 23 and the pre-supported reinforcement 3 are prepared using the MJS method.

[0036] This invention provides a construction method for a cut-and-cover support structure system for adding layers to an existing subway station, comprising the following steps:

[0037] S1. Launching shaft 4 and receiving shaft 5 are respectively set on opposite sides of the existing subway station 11.

[0038] In this embodiment, a launching shaft 4 and a receiving shaft 5 are formed on opposite sides of the existing subway station 11. The two ends of the non-closed bundled tube curtain 1 are connected to the launching shaft 4 and the receiving shaft 5 respectively through shaft connectors.

[0039] During construction, the launching shaft and receiving shaft will be constructed on opposite sides of the existing subway station 11. The temporary construction columns will support the lower two-story slab beams of the existing subway station.

[0040] After the internal structure of the launching shaft and receiving shaft is completed, the MJS reinforcement of the pipe jacking tunnel is carried out.

[0041] As a preferred implementation method, after the internal structure of the launching shaft and receiving shaft is completed, the following steps are also included:

[0042] S11. Install inclined bracing 8 between the lower part of the inner lining wall of launching shaft 4 and receiving shaft 5 and the bottom of launching shaft 4 and receiving shaft 5.

[0043] S12. Excavate the diaphragm wall of the transfer passage structure 10 at the position corresponding to the non-closed bundled pipe curtain 1 and the compartment pipe curtain 6 on the upper part of the inner lining wall.

[0044] S13. Install horizontal supports 9 on the upper part of the inner lining walls of the launching shaft 4 and the receiving shaft 5.

[0045] S14. At the lower part of the inner lining wall, corresponding to the non-closed bundled pipe curtain 1 and the compartment pipe curtain 6, excavate the diaphragm wall of the transfer passage structure 10 to allow the non-closed bundled pipe curtain 1 to be jacked up.

[0046] Specifically, inclined supports 8 are installed inside the launching shaft and receiving shaft. The inclined supports 8 are inclined at the bottom slab of the working shaft. The diaphragm wall and the sandwich soil of the new station are excavated at intervals, and the inner lining walls of the launching shaft and the receiving shaft are poured.

[0047] After the construction of the upper half of the inner lining wall of the launching shaft and the inner lining wall of the receiving shaft is completed, the upper half of the inner lining wall is supported by horizontal supports 9, and the lower half of the inner lining wall of the launching shaft and the inner lining wall of the receiving shaft are excavated at intervals.

[0048] S2. A non-closed bundled pipe curtain 1 is installed in the soil below the existing subway station 11 through the launching shaft 4 and receiving shaft 5.

[0049] See Figures 9 to 10 As shown, after the inner lining walls of the launching shaft and the receiving shaft are completed, the non-closed bundled pipe curtain structure is constructed.

[0050] The cross-section of the non-closed bundled tube curtain 1 is rectangular. A through-hole is provided at the top of the non-closed bundled tube curtain 1.

[0051] The non-closed bundled tube curtain is U-shaped overall. In this embodiment, the inner wall of the non-closed bundled tube curtain 1 is provided with multiple compartmentalized tube curtains 6, which divide the inner cavity of the non-closed bundled tube curtain 1 into multiple compartments along the width direction of the non-closed bundled tube curtain 1.

[0052] The construction of a non-closed bundled tube jacking includes steel tube jacking, concrete filling inside the tube jacking, and prestressing tensioning. During the steel tube jacking process, construction is temporarily suspended at the locations of temporary columns. After the tube jacking at the other locations is completed, permanent structural columns are used to support the temporary columns before the tube jacking construction at the temporary column locations is carried out.

[0053] S3. Construct a pre-supported solid body 3 inside the non-closed bundled tube curtain 1, so that the pre-supported solid body 3 is supported between the two opposite inner walls of the non-closed bundled tube curtain 1.

[0054] See Figure 11 As shown, the pre-supported reinforcement body inside the non-closed bundled tube curtain 1 mainly serves as a pre-support during the excavation of the soil inside the tube curtain.

[0055] S4. A frozen cushion layer 21 is formed by freezing the soil between the bottom of the non-closed bundled tube curtain 1 and the existing subway station 11.

[0056] S5. Construct a water-stopping reinforcement 23 on the outside of the non-closed bundled tube curtain 1, so that the water-stopping reinforcement 23 is connected to the outer wall of the non-closed bundled tube curtain 1, the frozen cushion layer 21 and the bottom of the existing subway station 11.

[0057] S6. Excavate the soil between the pre-supported solid body 3 and the bottom of the existing subway station 11.

[0058] S7. A reverse-construction top beam 22 is formed by casting at the bottom of the existing subway station 11, so that the reverse-construction top beam 22 is set in the through gap and connected to the inner wall of the non-closed bundled tube curtain 1 to form a connecting structure 2.

[0059] Continue to combine Figure 11 As shown, from the starting well or receiving well, the construction connection structure includes water-stopping reinforcement, pipe curtain pre-support reinforcement, and freezing pad. Among them, the pipe curtain water-stopping reinforcement and freezing pad mainly play the roles of water-stopping and vertical force transmission.

[0060] As a preferred embodiment, the water-stopping reinforcement 23 and the pre-supported reinforcement 3 are prepared using the MJS method (all-around high-pressure jetting method).

[0061] In a preferred embodiment, the two ends of the non-closed bundled tube curtain 1 are connected to the launching well 4 and the receiving well 5 respectively through well joints 12.

[0062] For details, please refer to Figure 13As shown, the construction shaft joint connects the non-closed bundled pipe curtain to the inner lining walls of the launching shaft and the receiving shaft, forming a whole. Afterwards, the upper soil of the pre-supported reinforced body is excavated, and the top beam is constructed in reverse.

[0063] In this embodiment, there are multiple reverse-construction top beams 22. Some of the reverse-construction top beams 22 are connected to the compartment tube curtain 6. A freezing pad layer 21 is provided between the compartment tube curtain 6 and the bottom of the existing subway station 11.

[0064] In a preferred embodiment, multiple reverse-operation top beams 22 are arranged along the width direction of the non-closed bundled tube curtain 1. Steel supports 7 connect the multiple reverse-operation top beams 22.

[0065] Steel supports are used between two adjacent inverted top beams. The inverted top beams serve to isolate the water and soil inside and outside the pipe curtain and to transfer force.

[0066] Before constructing the transfer passage structure, the soil of multiple compartments was excavated in the order of first the middle and then the two sides. By excavating the soil between the bottom of the pre-supported solid body 3 and the non-closed bundled tube curtain 1 and removing the pre-supported solid body 3, a construction space for constructing the ring channel structure was formed within the non-closed bundled tube curtain 1.

[0067] In this embodiment, after excavating the soil within one compartment to the bottom, the transfer passage structure within that compartment is constructed. The soil inside both compartments is excavated sequentially towards the opposite sides of the non-closed bundled pipe curtain to the bottom of the pipe curtain. Then, the middle compartment pipe curtain is removed, and the remaining portion of the transfer passage structure is constructed.

[0068] The underground expansion support structure system for adding layers to existing subway stations, as described in this invention, ensures the connectivity of the new station's platform level, enabling platform transfers. The pipe jacking can be constructed close to the existing station's foundation slab, eliminating the need for deepening during the design of the connecting lines. Simultaneously, the pipe jacking itself, through prestressed tensioning and manhole joints, forms a relatively rigid semi-enclosed structure, providing support for the soil outside the tunnel. It is independent of geological conditions and can be constructed in any geological stratum. Only pipe sections need to be reinforced upon entering and exiting the tunnel, requiring a relatively small amount of reinforcement. The soil inside the pipe jacking can be excavated in a single compartment, significantly increasing construction speed. Through the non-closed bundled pipe jacking and compartmentalized pipe jacking, it provides support for the existing station above, effectively reducing disturbance to the old station during the construction of the lower tunnel, exhibiting good geological adaptability and safety.

[0069] The existing subway station underground expansion support structure system of the present invention forms a new type of retaining structure system with the old station through non-closed bundled pipe curtain, which serves as the retaining structure of the underground transfer passage.

[0070] The non-closed bundled pipe jacking system of the underground expansion support structure for adding layers to existing subway stations in this invention is connected to the existing subway station via a connecting structure. This connecting structure employs MJS water-stopping reinforcement and a freezing pad layer to treat the gap between the non-closed bundled pipe jacking and the existing subway station, serving both force transmission and water-stopping functions. Furthermore, a reverse-construction top beam is cast at the bottom of the existing subway station, connecting the pipe jacking to the existing subway station. This reverse-construction top beam is a permanent-temporary combined structure, also acting as a corbel to transmit horizontal and vertical forces, ensuring continuous force transmission with the existing subway station and reducing the stress on the existing subway station's foundation slab.

[0071] To address the issue of connectivity between the circular shield tunnel segment structure and the existing subway station's base slab structure, the present invention provides a tunnel expansion support structure system for adding layers to existing subway stations, ensuring connectivity between the new station's platform level and enabling platform transfer functionality.

[0072] To address the issue of increasing the burial depth of circular shield tunnel segments, the present invention provides a tunnel jacking system for the underground expansion support structure of existing subway stations that can be constructed close to the existing station floor slab, eliminating the need for deepening during the design of the tunnel nodes.

[0073] To address the issues of soil reinforcement quality and geological adaptability in the underground excavation structure of the mining method, which relies on the underground excavation for primary and secondary lining, the present invention provides an underground expansion support structure system for adding layers to existing subway stations. This system utilizes a non-closed bundled pipe curtain structure as the retaining structure for the underground expansion layer, which has high rigidity and good safety. At the same time, it is not dependent on geological conditions and can be constructed in any geological stratum.

[0074] To address the issue of large reinforcement volumes in the primary and secondary lining structures of underground mining projects, the existing underground expansion support structure system for adding layers to existing subway stations only requires reinforcement of pipe sections entering and exiting the tunnel, resulting in a smaller reinforcement volume.

[0075] To address the issue of slow construction speed caused by multiple excavations of the pilot tunnel in the underground tunneling structure with primary and secondary lining in the mining method, the present invention provides a pipe jacking support structure system for the underground expansion of existing subway stations that allows for single-compartment, one-time excavation of the soil inside the pipe jacking, greatly increasing the construction speed.

[0076] To address the issue of significant disturbance to the upper station during the construction of the underground tunnel with primary and secondary lining in the mining method, the present invention provides a support structure system for the underground expansion of existing subway stations by adding layers downwards. This system uses non-closed bundled pipe curtains and compartmentalized pipe curtains to support the existing upper station, effectively reducing the disturbance to the old station caused by the construction of the lower passage.

[0077] To address the issues of difficulty in opening the top of the pipe curtain and track relocation in underground excavation projects for adding floors to existing subway stations using closed-loop pipe curtain structures, the present invention provides a non-closed-loop pipe curtain support structure system for underground excavation projects for adding floors to existing subway stations. This eliminates the need for a top pipe curtain, avoiding the problem of opening the top, and also reduces the space required for one row of pipe curtains at the top, thus avoiding the problem of track relocation.

[0078] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A support structure system for the underground expansion of an existing subway station by adding a lower level, characterized in that, include: A non-closed bundled tube curtain is installed in the soil below an existing subway station. A through gap is formed on the side of the non-closed bundled tube curtain facing the existing subway station. The through gap is set along the length direction of the non-closed bundled tube curtain. The connecting structure includes a freezing pad, a reverse-operation top beam, and a water-stopping reinforcement. The freezing pad is placed between the non-closed bundled tube curtain and the bottom of the existing subway station. The reverse-operation top beam is cast into the bottom of the existing subway station and is located within the through gap. The reverse-operation top beam is connected to the inner wall of the non-closed bundled tube curtain. The water-stopping reinforcement is connected to the outer wall of the non-closed bundled tube curtain, the freezing pad, and the bottom of the existing subway station. The pre-supported reinforcement is supported between the two opposing inner walls of the non-closed bundled tube curtain.

2. The underground excavation support structure system for adding layers to existing subway stations according to claim 1, characterized in that, The cross-section of the non-closed bundled tube curtain is rectangular, and the through-hole is located at the top of the non-closed bundled tube curtain.

3. The underground excavation support structure system for adding layers to existing subway stations according to claim 1, characterized in that, The number of the reverse-operation top beams is multiple, and the multiple reverse-operation top beams are arranged along the width direction of the non-closed bundled tube curtain, and the multiple reverse-operation top beams are connected by steel supports.

4. The cut-and-cover support structure system for adding layers to existing subway stations according to claim 1, characterized in that, The water-stopping reinforcement and the pre-supported reinforcement are prepared using the MJS method.

5. The cut-and-cover support structure system for adding layers to existing subway stations according to claim 1, characterized in that, The existing subway station has a launching shaft and a receiving shaft on opposite sides. The two ends of the non-closed bundled tube curtain are connected to the launching shaft and the receiving shaft respectively through shaft joints.

6. The underground excavation support structure system for adding layers to existing subway stations according to claim 1, characterized in that, The inner wall of the non-closed bundled tube curtain is provided with multiple compartmentalized tube curtains, which divide the inner cavity of the non-closed bundled tube curtain into multiple compartments along the width direction of the non-closed bundled tube curtain.

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