Underground excavation extension supporting structure system for downward storey adding of existing subway station

Abstract

The invention discloses an underground excavation extension support structure system for downward storey adding of an existing subway station, and the system comprises a non-closed bunched pipe curtain which is arranged in a soil body below the existing subway station, and one side, facing the existing subway station, of the pipe curtain is provided with a through gap; the connecting structure comprises a freezing cushion layer, a reverse top beam and a water stop reinforcing piece, the freezing cushion layer is arranged between the pipe roofing and the bottom of the existing subway station in a cushion mode, and the reverse top beam is poured at the bottom of the existing subway station and arranged in the through notch and connected with the inner wall of the pipe roofing. The water stop reinforcing member is connected to the outer wall of the pipe roofing, the freezing cushion layer and the bottom of the existing subway station; and the pre-supporting reinforcing body is supported between the two opposite inner walls of the pipe curtain. The invention solves the problems that the existing shield method or mining method crossing construction adopted for the downward layer-adding expansion and reconstruction of the old station is difficult to realize platform transfer or large in reinforcement amount, large in construction disturbance and low in construction speed.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, and in particular to a dark excavation expansion support structure system for adding floors downward to an existing subway station. Background Art

[0002] With the construction of urban subway projects, new subway lines currently face a large number of problems in the expansion and reconstruction of old stations. Currently, subway intersection node projects often use shield or mining methods for crossing construction. Shield crossing often has problems such as the platform level of the new station is not connected, it is difficult to achieve platform transfer, and the line is buried deep. Mining crossing often has problems such as high construction risk, large reinforcement volume, slow construction speed, and large disturbance to the upper station structure.

[0003] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0004] In order to overcome the defects of the existing technology, a dark excavation expansion support structure system for adding floors to existing subway stations is provided to solve the problems of difficulty in realizing platform transfer or large reinforcement volume, large construction disturbance and slow construction speed when using the existing shield method or mining method to cross the construction of the old station for adding floors and expanding the station downward.

[0005] In order to achieve the above purpose, a supporting structure system for underground excavation and expansion of an existing subway station is provided, comprising:

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

[0007] A connection structure, comprising a freezing pad, a reverse top beam and a water-stop reinforcement member, wherein the freezing pad is arranged between the non-closed bundled pipe curtain and the bottom of the existing subway station, the reverse top beam is cast at the bottom of the existing subway station and arranged in the through-notch, the reverse top beam is connected to the inner wall of the non-closed bundled pipe curtain, and the water-stop reinforcement member is connected to the outer wall of the non-closed bundled pipe curtain, the freezing pad and the bottom of the existing subway station;

[0008] The pre-support reinforcement body is supported between two opposite 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-notch is arranged at the top of the non-closed bundled tube curtain.

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

[0011] Furthermore, the water-stop reinforcement member and the pre-support reinforcement member are prepared by MJS method.

[0012] Furthermore, a departure shaft and a receiving shaft are formed on opposite sides of the existing subway station, and both ends of the non-closed bundled pipe curtain are respectively connected to the departure shaft and the receiving shaft through shaft joints.

[0013] Furthermore, the inner wall of the non-closed bundled tube curtain is provided with a plurality of compartment tube curtains, and the plurality of compartment tube curtains divide the inner cavity of the non-closed bundled tube curtain into a plurality of compartments along the width direction of the non-closed bundled tube curtain.

[0014] The beneficial effect of the present invention is that the concealed excavation expansion support structure system of the existing subway station of the present invention can ensure the connection of the platform layer of the new station and realize the function of platform transfer. The pipe curtain can be constructed close to the existing station floor, and there is no need to deepen the node line design. At the same time, the pipe curtain itself forms a semi-enclosed structure with relatively large rigidity through prestressed tensioning and well joints, which plays a supporting role on the soil outside the channel. It is independent of the formation conditions and can be constructed in any formation. Only the pipe sections entering and exiting the hole need to be reinforced, and the reinforcement volume is relatively small. The soil inside the pipe curtain can be excavated in a single compartment at one time, which greatly increases the construction speed. Through the non-closed bundled pipe curtain and the compartment pipe curtain, it plays a supporting role for the existing upper station, which can effectively reduce the disturbance of the lower channel construction to the old station, and has good formation adaptability and safety.

[0015] The underground excavation expansion support structure system of the existing subway station with additional floors formed by the non-closed bundled pipe curtain and the old station forms a new type of enclosure structure system, which plays the role of the underground excavation transfer passage enclosure structure.

[0016] The non-closed bundled pipe curtain of the concealed excavation expansion support structure system of the existing subway station of the present invention is connected to the existing subway station through a connecting structure, wherein the connecting structure adopts MJS water-stop reinforcement and freezing pad to process the gap between the non-closed bundled pipe curtain and the existing subway station, playing the role of force transmission and water stopping. On the other hand, the bottom of the existing subway station is cast to form a reverse top beam, which serves to connect the pipe curtain with the existing subway station. The reverse top beam is a permanent and temporary combined structure, and the reverse top beam also serves as a corbel to play the role of horizontal and vertical force transmission, ensuring the continuity of force transmission with the existing subway station and reducing the force on the bottom plate of the existing subway station. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0018] Figure 1 It is a structural schematic diagram of a support structure system for underground excavation and expansion of an existing subway station with additional floors according to an embodiment of the present invention.

[0019] Figure 2 for Figure 1 Cross-sectional view at EE in FIG.

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

[0021] Figures 4 to 13 It is a schematic diagram of the steps of a construction method for a concealed excavation expansion support structure system for adding floors downwards to an existing subway station according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0023] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] Reference Figures 1 to 13 As shown, Figure 6 for Figure 5 The cross-sectional view at AA in the figure is as follows: Figure 8 for Figure 7 The cross-sectional view at BB in the figure is as follows: Fig.10 for Fig. 9 The cross-sectional view at CC in the figure, Fig.11 for Fig. 9 The cross-sectional view at DD in the figure shows that the present invention provides a support structure system for the underground excavation expansion of an existing subway station with additional floors, comprising: a non-closed bundled pipe curtain 1, a connection structure 2, and a pre-support reinforcement body 3.

[0025] The non-closed bundled pipe 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-notch is formed on the side of the non-closed bundled tube curtain 1 facing the existing subway station 11. The through-notch is arranged along the length direction of the non-closed bundled tube curtain 1. The non-closed bundled tube curtain is U-shaped as a whole. The through-notch is arranged 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 a plurality of compartment tube curtains 6. The plurality of compartment tube curtains 6 divide the inner cavity of the non-closed bundled tube curtain 1 into a plurality of compartments along the width direction of the non-closed bundled tube curtain 1.

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

[0029] Specifically, the freezing pad 21 is provided between the non-closed bundled pipe curtain 1 and the bottom of the existing subway station 11. In this embodiment, the freezing pad is formed by freezing the soil between the non-closed bundled pipe curtain 1 and the bottom of the existing subway station 11.

[0030] The reverse top beam 22 is cast at the bottom of the existing subway station 11 and is arranged in the through-cut. The reverse top beam 22 is connected to the inner wall of the non-closed bundled tube curtain 1.

[0031] There are multiple reverse top beams 22. The multiple reverse top beams 22 are arranged along the width direction of the non-closed bundled tube curtain 1. Steel supports 7 are connected between the multiple reverse top beams 22.

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

[0033] The water-stop reinforcement member 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-support reinforcement body 3 is supported between two opposite inner walls of the non-closed bundled tube curtain 1 .

[0035] As a preferred embodiment, the water-stop reinforcement member 23 and the pre-support reinforcement member 3 are prepared by the MJS method.

[0036] The present invention provides a construction method for a concealed excavation expansion support structure system for adding floors downwards to an existing subway station, comprising the following steps:

[0037] S1. A departure shaft 4 and a receiving shaft 5 are respectively set on opposite sides of an existing subway station 11.

[0038] In this embodiment, a departure shaft 4 and a receiving shaft 5 are formed on opposite sides of an existing subway station 11. Both ends of the non-closed bundled pipe curtain 1 are connected to the departure shaft 4 and the receiving shaft 5 respectively through shaft joints.

[0039] During construction, the departure shaft and the receiving shaft are first constructed on opposite sides of the existing subway station 11. The temporary columns are constructed to support the cross beams of the lower second floor slab of the top of the existing subway station.

[0040] After the internal structure construction of the starting well and the receiving well is completed, the MJS reinforcement of the pipe curtain top pipe in and out of the hole is carried out.

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

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

[0043] S12, excavating the ground-connected wall of the transfer passage structure 10 at the position of 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 parts of the inner lining walls of the launching well 4 and the receiving well 5.

[0045] S14, excavating the ground-connected wall of the transfer passage structure 10 at the lower part of the lining wall corresponding to the position of the non-closed bundled pipe curtain 1 and the compartment pipe curtain 6 for the jacking construction of the non-closed bundled pipe curtain 1.

[0046] Specifically, in the starting shaft and the receiving shaft, an inclined support 8 is set up. The inclined support 8 is inclined at the bottom plate of the working shaft. The ground connection wall and sandwich soil of the new station are excavated at intervals, and the lining wall of the starting shaft and the lining wall of the receiving shaft are poured.

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

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

[0049] See also Figures 9 and 10 As shown, after the construction of the inner lining wall of the starting well and the inner lining wall of the receiving well is completed, the construction of the non-closed bundled pipe curtain structure is carried out.

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

[0051] The non-closed bundled tube curtain is in a U-shape as a whole. In this embodiment, the inner wall of the non-closed bundled tube curtain 1 is provided with a plurality of compartment tube curtains 6, which divide the inner cavity of the non-closed bundled tube curtain 1 into a plurality of compartments along the width direction of the non-closed bundled tube curtain 1.

[0052] The construction of the non-closed bundled pipe curtain includes the jacking of the steel pipe curtain, the filling of concrete in the pipe curtain, and the prestressing. During the jacking process of the steel pipe curtain, the temporary column position is temporarily stopped. After the jacking of the pipe curtain at other positions is completed, the temporary column is replaced with a permanent structural column, and then the jacking construction of the pipe curtain at the temporary column position is carried out.

[0053] S3, constructing a pre-support reinforcement body 3 in the non-closed bundled pipe roof 1, so that the pre-support reinforcement body 3 is supported between two opposite inner walls of the non-closed bundled pipe roof 1.

[0054] See also Fig.11 As shown, the pre-support reinforcement body in the non-closed bundled pipe curtain 1 mainly plays a pre-support role when the soil inside the pipe curtain is excavated.

[0055] S4, forming a freezing cushion layer 21 by freezing the soil between the non-closed bundled pipe curtain 1 and the bottom of the existing subway station 11.

[0056] S5 , constructing a water-stop reinforcement member 23 on the outer side of the non-closed bundled pipe curtain 1 , so that the water-stop reinforcement member 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 .

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

[0058] S7. Cast a reverse top beam 22 at the bottom of the existing subway station 11 , so that the reverse top beam 22 is arranged in the through-notch and connected to the inner wall of the non-closed bundled tube curtain 1 to form a connection structure 2 .

[0059] Continue to combine Fig.11 As shown, from the starting well or the receiving well, the water-stop reinforcement parts, the pipe curtain pre-support reinforcement parts and the freezing pad layer of the connecting structure are constructed, among which the pipe curtain water-stop reinforcement parts and the freezing pad layer mainly play the role of water-stopping and vertical force transmission.

[0060] As a preferred embodiment, the water-stop reinforcement member 23 and the pre-support reinforcement member 3 are prepared by MJS method (omnidirectional high-pressure spraying method).

[0061] As a preferred implementation, both ends of the non-closed bundled pipe curtain 1 are connected to the starting well 4 and the receiving well 5 respectively through well joints 12 .

[0062] For details, see Fig.13As shown, the well joint is constructed to connect the non-closed bundled pipe curtain with the inner lining wall of the starting well and the inner lining wall of the receiving well into a whole. After that, the upper soil of the pre-support reinforcement body is excavated first, and the top beam is constructed in reverse.

[0063] In this embodiment, there are a plurality of reverse top beams 22. Some of the reverse top beams 22 are respectively connected to the compartment pipe curtain 6. A freezing pad 21 is provided between the compartment pipe curtain 6 and the bottom of the existing subway station 11.

[0064] As a preferred embodiment, a plurality of reverse top beams 22 are arranged along the width direction of the non-closed bundled tube curtain 1. Steel supports 7 are connected between the plurality of reverse top beams 22.

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

[0066] Before constructing the transfer channel structure, the soil of multiple compartments is excavated in the order of the middle first and then the two sides. By excavating the soil between the pre-support reinforcement body 3 and the bottom of the non-closed bundled pipe curtain 1 and removing the pre-support reinforcement body 3, a construction space for constructing the annular groove channel structure is formed in the non-closed bundled pipe curtain 1.

[0067] In this embodiment, when the soil in one compartment is excavated to the bottom of the compartment, the transfer passage structure in the compartment is constructed. The internal soil of the left and right compartments is excavated to the bottom of the pipe curtain in sequence toward the opposite sides of the non-closed bundled pipe curtain. Then the middle compartment pipe curtain is cut off and the remaining part of the transfer passage structure is constructed.

[0068] The concealed excavation expansion support structure system of the existing subway station of the present invention can ensure the connection of the platform layer of the new station and realize the function of platform transfer. The pipe curtain can be constructed close to the existing station floor, and there is no need to deepen the node line design. At the same time, the pipe curtain itself forms a semi-enclosed structure with relatively large rigidity through prestressed tensioning and well joints, which plays a supporting role on the soil outside the channel. It is independent of the formation conditions and can be constructed in any formation. Only the pipe sections entering and exiting the hole need to be reinforced, and the reinforcement volume is relatively small. The soil inside the pipe curtain can be excavated in a single compartment at one time, which greatly increases the construction speed. Through the non-closed bundled pipe curtain and the compartment pipe curtain, it plays a supporting role for the existing upper station, which can effectively reduce the disturbance of the lower channel construction to the old station, and has good formation adaptability and safety.

[0069] The underground excavation expansion support structure system of the existing subway station with additional floors formed by the non-closed bundled pipe curtain and the old station forms a new type of enclosure structure system, which plays the role of the underground excavation transfer passage enclosure structure.

[0070] The non-closed bundled pipe curtain of the concealed excavation expansion support structure system of the existing subway station of the present invention is connected to the existing subway station through a connecting structure, wherein the connecting structure adopts MJS water-stop reinforcement parts and freezing pads to process the gap between the non-closed bundled pipe curtain and the existing subway station, playing the role of force transmission and water stopping. On the other hand, the bottom of the existing subway station is cast to form a reverse top beam, which serves to connect the pipe curtain and the existing subway station. The reverse top beam is a permanent and temporary combined structure, and the reverse top beam also serves as a corbel to play the role of horizontal and vertical force transmission, ensuring the continuity of force transmission with the existing subway station and reducing the force on the bottom plate of the existing subway station.

[0071] In order to solve the problem of the connection between the circular shield segment structure and the bottom plate structure of the existing subway station above, the concealed excavation expansion support structure system of the existing subway station with additional layers downward can ensure the connection of the platform layer of the new station and realize the function of platform transfer.

[0072] In view of the problem that the circular shield segment structure needs to increase the buried depth of the line, the pipe curtain of the dark excavation expansion support structure system of the existing subway station downwardly added layer of the present invention can be constructed closely against the existing station floor, and there is no need to deepen the node line during design.

[0073] In view of the problem of soil reinforcement quality and stratum adaptability of the primary lining plus secondary lining structure of the underground excavation by the mining method, the underground excavation expansion support structure system for adding layers to the existing subway station of the present invention utilizes a non-closed bundled pipe curtain structure as the enclosure structure for the underground excavation adding layers, which has high rigidity and good safety. At the same time, it is not dependent on stratum conditions and can be constructed in any stratum.

[0074] Aiming at the problem of large reinforcement volume of primary and secondary lining structures in mining method dark excavation, the dark excavation expansion support structure system for adding layers to existing subway stations in the present invention only requires pipe section inlet and outlet reinforcement, and the reinforcement volume is relatively small.

[0075] Aiming at the problem of slow construction speed due to multiple excavations of pilot tunnels for the primary lining plus secondary lining structure of the mining method, the soil inside the pipe curtain of the existing subway station downward excavation expansion support structure system of the present invention can be excavated in a single chamber at one time, which greatly increases the construction speed.

[0076] In view of the problem that the construction process of the primary lining and secondary lining structure of the mining method causes significant disturbance to the upper station, the underground excavation expansion support structure system of the existing subway station with additional floors supports the upper existing station through non-closed bundled pipe curtains and compartment pipe curtains, which can effectively reduce the disturbance of the lower passage construction to the old station.

[0077] In view of the problems of difficulty in opening holes at the top of the closed bundled pipe curtain structure and downward shifting of the line in the dark excavation expansion project of adding floors to the existing subway station, the dark excavation expansion support structure system of the existing subway station with additional floors adopts a non-closed bundled pipe curtain, eliminates the top pipe curtain, avoids the problem of opening holes at the top, and at the same time reduces the space of one row of pipe curtains at the top, avoiding the problem of downward shifting of the line.

[0078] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A support structure system for underground excavation and expansion of an existing subway station, characterized in that: include: A non-closed bundled pipe curtain is installed in the soil below the existing subway station. A through-notch is formed on the side of the non-closed bundled pipe curtain facing the existing subway station. The through-notch is arranged along the length direction of the non-closed bundled pipe curtain. A connection structure, comprising a freezing pad, a reverse top beam and a water-stop reinforcement member, wherein the freezing pad is arranged between the non-closed bundled pipe curtain and the bottom of the existing subway station, the reverse top beam is cast at the bottom of the existing subway station and arranged in the through-notch, the reverse top beam is connected to the inner wall of the non-closed bundled pipe curtain, and the water-stop reinforcement member is connected to the outer wall of the non-closed bundled pipe curtain, the freezing pad and the bottom of the existing subway station; The pre-support reinforcement body is supported between two opposite inner walls of the non-closed bundled tube curtain.

2. The dark excavation expansion support structure system for adding floors to an existing subway station according to claim 1 is characterized in that: The cross section of the non-closed bundled tube curtain is rectangular, and the through-notch is arranged at the top of the non-closed bundled tube curtain.

3. The dark excavation expansion support structure system for adding floors to an existing subway station according to claim 1 is characterized in that: There are multiple reverse top beams, and the multiple reverse top beams are arranged along the width direction of the non-closed bundled tube curtain. Steel supports are connected between the multiple reverse top beams.

4. The dark excavation expansion support structure system for adding floors to an existing subway station according to claim 1 is characterized in that: The water-stop reinforcement member and the pre-support reinforcement member are prepared by the MJS method.

5. The dark excavation expansion support structure system for adding floors to an existing subway station according to claim 1 is characterized in that: A departure well and a receiving well are formed on opposite sides of the existing subway station, and both ends of the non-closed bundled pipe curtain are respectively connected to the departure well and the receiving well through well joints.

6. The dark excavation expansion support structure system for adding floors to an existing subway station according to claim 1 is characterized in that: The inner wall of the non-closed bundled tube curtain is provided with a plurality of compartment tube curtains, and the plurality of compartment tube curtains divide the inner cavity of the non-closed bundled tube curtain into a plurality of compartments along the width direction of the non-closed bundled tube curtain.

Images