Construction method for the exit of a shield machine receiving a steel pipe jacked in a subway station with silt geological conditions

Abstract

The present invention relates to a construction method for a shield machine to exit the hole by jacking a steel pipe in a subway station with silt geological conditions, including steps: reserving an annular steel blade and a conduit opening, constructing a grouting hole, constructing a reinforcement water stop ring, freezing construction at the ring opening, breaking part of the support structure, arranging a jacking system, gradually jacking the steel pipe in segments, and injecting foamed concrete into the steel pipe; this method overcomes the risks of unstable and easily collapsible silt strata, ensuring project safety; it avoids the disadvantages of pouring mortar or inert slurry, and does not produce any waste liquid or waste, realizing the green reception of the shield machine; it eliminates the equipment for setting horizontal support reaction forces, utilizes the friction between the steel pipe and the surrounding silt layer to balance the horizontal thrust generated during the shield machine reception process, reduces the use of construction equipment, and thus improves the construction efficiency.

Description

Technical Field

[0001] The present invention is applicable to the construction of the shield machine receiving and exiting the tunnel in the subway station, and particularly relates to a construction method for jacking a steel pipe to receive the shield machine exiting the tunnel in a subway station with silty soil geology. Background Art

[0002] In urban subway construction, the shield method is mostly used for tunnel construction. Therefore, when the shield machine passes through the subway station, it is necessary to do a good job in receiving. At present, almost all subway stations use the method of setting up a steel sleeve to receive the shield machine. The publicly available technologies include: CN202110987360.5 A Construction Method for Receiving a Steel Sleeve of a Subway Shield Machine, CN201710533673.7 An Auxiliary Device for Shield Machine Starting and Receiving, CN201610703282.0 A Steel Sleeve Reaction Vehicle Device for Shield Machine Receiving, CN201610792320.4 A New Type of Shield Balanced Starting and Receiving Sleeve Device, CN202010832862.6 A Construction Method and Device for Receiving a Shield Machine with Water Filled in a Steel Sleeve, CN202022893622.5 A Double-Layer Ultra-Short Steel Sleeve System for Shield Machine Receiving, etc. All these methods require mortar filling and pressure holding tests for the steel sleeves in the subway station. The construction equipment is cumbersome, and after the shield machine is received, the waste mortar needs to be recycled. If the recycling is not proper, it may cause environmental pollution and other problems.

[0003] In addition, "CN109356596B A Method for Starting and Receiving a Shield Machine Using a Recyclable Diaphragm Wall and a Steel Sleeve" provides a method for receiving and starting a shield machine with a recyclable diaphragm wall. However, this method has a serious problem, that is, the instability failure of the groove wall and the sudden gushing of groundwater may occur when recycling the diaphragm wall. Especially in the silty soil layer, its stability is poor and it is easy to cause the collapse of the groove, which may lead to engineering construction. Therefore, the implementation of this technology is extremely difficult.

[0004] Therefore, there is an urgent need for a construction method for jacking a steel pipe to receive the shield machine exiting the tunnel in a subway station that overcomes the deficiencies of the current steel sleeve set in the station and has good implementability in the silty soil layer. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a construction method for jacking a steel pipe to receive the shield machine exiting the tunnel in a subway station with silty soil geology.

[0006] This construction method for jacking a steel pipe to receive the shield machine exiting the tunnel in a subway station with silty soil geology includes the following construction steps:

[0007] Step 1: Reserve an annular steel blade and conduit openings: When constructing the receiving side wall of the shield machine in the subway station, reserve an annular steel blade; and reserve a plurality of conduit openings outside the annular steel blade. Temporarily block the conduit openings;

[0008] Step 2. Construction and reinforcement of the grouting hole and the water stop ring: Drill into the silt layer through the conduit opening to form a grouting hole; conduct high-pressure grouting on the grouting hole to form a reinforced water stop ring;

[0009] Step 3. Freezing construction at the ring opening: The freezing equipment freezes the silt at the ring opening of the reinforced water stop ring through the freezing pipes to form a temporary freezing zone;

[0010] Step 4. Layout of the jacking system: Demolish the part of the support structure surrounded by the annular steel blade; layout the jacking system on the ground of the subway station inside the receiving side wall;

[0011] Step 5. Step-by-step jacking of the steel pipes in segments: Place the steel pipes into the jacking system, weld and seal the steel pipes and the annular steel blade, and then use the jacking system to jack the steel pipes and the annular steel blade into the reinforced water stop ring; weld and seal the subsequent sections of the steel pipes with the already jacked-in steel pipes and then jack them into the reinforced water stop ring; there are an injection port and an overflow port at the top of the last section of the steel pipe;

[0012] Step 6. Inject foam concrete into the steel pipes: Remove the jacking system, seal the tail end of the steel pipes, pour foam concrete through the injection port until the overflow port is full; remove the seals, freezing equipment and freezing pipes at the outer end of the steel pipes.

[0013] Preferably, in Step 1: The outer diameter of the annular steel blade is equal to the outer diameter of the jacking steel pipe, and the wall thickness of the annular steel blade is twice that of the jacking steel pipe; the rear end of the annular steel blade is welded to the jacking steel pipe; the length of the annular steel blade is equal to twice the thickness of the receiving side wall, the front end of the annular steel blade is located at the outer edge of the receiving side wall, and the rear end of the annular steel blade is inside the subway station, showing a rabbet shape; the length of the conduit opening is the sum of the thickness of the receiving side wall and the thickness of the support structure, the outer end of the conduit opening is flush with the outer edge of the support structure, and the inner end of the conduit opening is flush with the inner edge of the receiving side wall; the inclination angle of the conduit opening is controlled at 2-4°.

[0014] Preferably, the hole size and inclination angle of the grouting hole are the same as those of the conduit opening, and the horizontal length of the reinforced water stop ring is greater than the sum of the jacking length of the steel pipe, the length of the annular steel blade and the diameter of the steel pipe.

[0015] Preferably, when implementing Steps 4 to 6, the freezing equipment freezes the silt at the ring opening of the reinforced water stop ring again through the freezing pipes to keep the temporary freezing zone at the ring opening position of the reinforced water stop ring in the silt layer in a frozen state.

[0016] Preferably, in Step 5: The injection port and the overflow port of the last section of the steel pipe are located inside the subway station, and there are multiple water-swelling water stop rings on the inner wall of the outermost section of the steel pipe.

[0017] Preferably, in Step 5: The jacking length of the steel pipe and the annular steel blade is greater than the length of the shield machine, and the diameter of the steel pipe is greater than the outer diameters of the shield machine and the shield tunnel lining.

[0018] Preferably, Step 5 is specifically as follows: Remove the jacking system, clean the loose silt layer on the outer side of the steel pipe, then seal the tail end of the steel pipe, and pour foam concrete with the same strength as the silt layer in the steel pipe through the injection port on the steel pipe. Stop pouring when the overflow port is full; after the foam concrete solidifies and hardens, remove the seal at the outer end of the steel pipe, the freezing equipment on the ground and the freezing pipes at the ring opening, and complete the structure for receiving the shield machine when the jacked steel pipe exits the tunnel in the silty soil geological subway station, so as to receive the shield machine for exiting the tunnel operation.

[0019] The structure for receiving the shield machine when the jacked steel pipe exits the tunnel in the silty soil geological subway station is obtained by any of the above methods.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1) Compared with the current method of receiving the shield machine with a steel sleeve in the station, the present invention uses an external steel pipe method to achieve the smooth reception of the shield in the silty soil geological subway station. By pouring foam concrete in the steel pipe, the disadvantages of pouring mortar or inert slurry are avoided, and no waste liquid or waste is generated, realizing the green reception of the shield machine.

[0022] 2) Compared with setting a recyclable diaphragm wall, the present invention overcomes the risks of instability and easy collapse in the silty soil layer by setting a ring-shaped steel blade, a reinforced water stop ring and a temporary freezing zone, ensuring the safety of the project.

[0023] 3) The present invention omits the equipment for setting horizontal support reaction force during the process of receiving the shield machine, and uses the friction force between the steel pipe and the surrounding silty soil layer to balance the horizontal thrust generated during the process of receiving the shield machine, reducing the use of construction equipment, so improving the construction efficiency. Description of the Drawings

[0024] Figure 1 It is the elevation view reserved for the ring-shaped steel blade and the conduit opening;

[0025] Figure 2 It is the sectional view reserved for the ring-shaped steel blade and the conduit opening;

[0026] Figure 3 It is the sectional view of the grouting hole construction;

[0027] Figure 4 It is the sectional view of the construction of the reinforced water stop ring;

[0028] Figure 5 It is the sectional view of the freezing construction at the ring opening;

[0029] Figure 6 It is the sectional view of the partial demolition of the support structure;

[0030] Figure 7It is the sectional view of the jacking system layout;

[0031] Figure 8 It is the sectional view of the jacking construction of the first section of steel pipe;

[0032] Figure 9 It is the sectional view after the outermost section of steel pipe is laid out;

[0033] Figure 10 It is the sectional view after the foamed concrete construction is completed;

[0034] Figure 11 It is the structural construction process flow chart of the jacking steel pipe receiving the shield machine out of the hole in the silt geological subway station.

[0035] Among them, 1 - receiving side wall; 2 - conduit orifice; 3 - annular steel blade; 4 - support structure; 5 - silt layer; 6 - subway station ground; 7 - grouting hole; 8 - reinforcement water stop ring; 9 - freezing equipment; 10 - freezing pipe; 11 - temporary freezing area; 12 - jacking system; 13 - steel pipe; 14 - injection port; 15 - overflow port; 16 - water - swelling water stop ring; 17 - foamed concrete. Specific implementation manners

[0036] The following further describes the present invention in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0037] Embodiment 1

[0038] As an embodiment, as Figure 11 shown, a construction method for the structure of the jacking steel pipe receiving the shield machine out of the hole in the silt geological subway station includes the following construction steps:

[0039] Step 1. Reserve the annular steel blade and the conduit orifice: When constructing the receiving side wall 1 of the shield machine in the subway station, reserve the annular steel blade 3; synchronously, symmetrically reserve a plurality of annular conduit orifices 2 outside the annular steel blade 3. The outer diameter of the annular steel blade 3 is equal to the outer diameter of the jacking steel pipe 13, and the wall thickness of the annular steel blade 3 is twice that of the jacking steel pipe 13; the rear end of the annular steel blade 3 is welded to the jacking steel pipe 13; the length of the annular steel blade 3 is equal to twice the thickness of the receiving side wall 1, the front end of the annular steel blade 3 is located at the outer edge of the receiving side wall 1, and the rear end of the annular steel blade 3 is inside the subway station, showing a rabbet shape. The length of the conduit orifice 2 is the sum of the thickness of the receiving side wall 1 and the thickness of the support structure 4, the outer end of the conduit orifice 2 is flush with the outer edge of the support structure 4, and the inner end of the conduit orifice 2 is flush with the inner edge of the receiving side wall 1; the inclination angle of the conduit orifice 2 is controlled within the range of 2 - 4 degrees; after the conduit orifice 2 is reserved, it needs to be temporarily blocked.

[0040] Step 2. Construction of grouting holes: Through the conduit orifice 2, drill holes in the supporting structures 4 such as the water-stop curtain and diaphragm wall on the outside of the receiving side wall 1. After drilling, the size and inclination angle of the holes formed on the supporting structure 4 are the same as those of the conduit orifice 2, forming multiple annular grouting holes 7.

[0041] Construction of the reinforcement water-stop ring: Drawing on the technology of advanced support grouting with small conduits in tunnel construction, in the subway station, using the grouting holes 7, laterally insert small conduits, and then conduct high-pressure grouting, thereby forming a reinforcement water-stop ring 8 in the vertical direction on the outside of the receiving side wall 1 to stabilize the surrounding silt layer 5 and facilitate the construction of jacking the steel pipe 13. The horizontal length of the water-stop ring is greater than the sum of the jacking length of the steel pipe 13, the length of the annular steel blade 3, and the diameter of the steel pipe 13.

[0042] Step 3. Freezing construction at the ring orifice: Drawing on the technology of the freezing method, arrange freezing equipment 9 on the ground, vertically insert multiple freezing pipes 10 in sequence through the ground to the ring orifice of the reinforcement water-stop ring 8, inject liquid nitrogen, and freeze the silt at the ring orifice to form a temporary freezing zone 11, thereby blocking the seepage of groundwater into the subway station.

[0043] Step 4. Demolish part of the supporting structure: Demolish the supporting structure 4 surrounded by the annular steel blade 3; at the same time, according to needs, freeze the ring orifice again to keep it in a frozen state.

[0044] Layout of the jacking system: Drawing on the technology of pipe jacking construction, arrange the jacking system 12 for the corresponding steel pipe 13 on the inner side of the receiving side wall 1 of the subway station ground 6, and the position where the steel pipe 13 is located corresponds to that of the annular steel blade 3; at the same time, according to needs, freeze the ring orifice again to keep it in a frozen state.

[0045] Step 5. Gradually jack the steel pipe in segments: Place the first section of the steel pipe 13 into the jacking system 12. After welding and sealing the first section of the steel pipe 13 and the annular steel blade 3, then use the jacking system 12 to jack the first section of the steel pipe 13 and the annular steel blade 3 into the reinforcement water-stop ring 8; and so on, jack other sections of the steel pipe 13 into the reinforcement water-stop ring 8 as well, and the steel pipes 13 also need to be welded and sealed; at the same time, according to needs, freeze the ring orifice again to keep it in a frozen state; there are an injection port 14 and an overflow port 15 at the top of the outermost section of the steel pipe 13, the injection port 14 and the overflow port 15 are located inside the subway station, and there are multiple water-swellable water-stop rings 16 on the inner wall of the outermost section of the steel pipe 13. The jacking length of the steel pipe 13 and the annular steel blade 3 should be greater than the length of the shield machine. The diameter of the steel pipe 13 is greater than the outer diameters of the shield machine and the shield tunnel lining.

[0046] Step 6: Inject foamed concrete into the steel pipe: Remove the jacking system 12, clean the loose silt layer 5 on the outer side of the steel pipe 13, then seal the outer end of the steel pipe 13 located on the ground 6 of the subway station, and pour foamed concrete 17 with the same strength as the silt layer 5 in the steel pipe 13 through the injection port 14 on the steel pipe 13. Stop pouring when the overflow port 15 is full; after the foamed concrete 17 solidifies and hardens, remove the seal at the outer end of the steel pipe 13, the freezing equipment 9 on the ground and the freezing pipes 10 at the ring opening, and complete the structure for receiving the shield machine to exit the hole inside the subway station with silt geological conditions, so as to smoothly receive the shield machine to exit the hole operation.

[0047] Embodiment 2

[0048] As another embodiment, a structure for receiving a shield machine to exit the hole by jacking a steel pipe inside a subway station with silt geological conditions obtained in Embodiment 1 is as Figures 1 to 10 shown, including: receiving side wall 1, annular steel blade 3, silt layer 5, subway station ground 6, grouting hole 7, reinforcement and water stop ring 8, freezing equipment 9, temporary freezing zone 11, jacking system 12 and steel pipe 13;

[0049] A support structure 4 is provided between the receiving side wall 1 and the silt layer 5; the annular steel blade 3 is arranged at the exit position of the steel pipe 13 on the receiving side wall 1. The front end of the annular steel blade 3 is located at the outer edge of the receiving side wall 1, and the rear end of the annular steel blade 3 is inside the subway station; the rear end of the annular steel blade 3 is in a rabbet shape. The outer diameter of the annular steel blade 3 is equal to the outer diameter of the steel pipe 13, and the wall thickness of the annular steel blade 3 is twice that of the steel pipe 13. Several conduit openings 2 are arranged around the annular steel blade 3, and the conduit openings 2 penetrate through the receiving side wall 1 and the support structure 4;

[0050] One end of the grouting hole 7 is connected to the conduit opening 2, and the other end extends into the silt layer 5; the hole size and inclination angle of the grouting hole 7 are the same as those of the conduit opening 2; the inclination angle of the conduit opening 2 is 2 - 4°. A reinforcement and water stop ring 8 is formed by pouring in several circumferentially distributed grouting holes 7, and the inclination angle of the reinforcement and water stop ring 8 is also 2 - 4°. The horizontal length of the reinforcement and water stop ring 8 is greater than the sum of the jacking length of the steel pipe 13, the length of the annular steel blade 3 and the diameter of the steel pipe 13.

[0051] The freezing equipment 9 is arranged on the ground. The freezing equipment 9 is connected with freezing pipes 10. The bottom of the freezing pipes 10 extends into the ring opening position of the reinforcement and water stop ring 8 in the silt layer 5, and a temporary freezing zone 11 is arranged at the ring opening position of the reinforcement and water stop ring 8 in the silt layer 5;

[0052] The jacking system 12 is installed on the ground 6 of the subway station on the receiving side wall 1. Several sections of steel pipes 13 are welded and sealed to each other, and the first section of the steel pipe 13 is welded and sealed to the annular steel blade 3. The steel pipe 13 is installed on the jacking system 12 and is jacked into the silt layer 5 section by section, and the end of the first section of the steel pipe 13 corresponds to the spigot at the rear end of the annular steel blade 3. After jacking, the steel pipe 13 and the annular steel blade 3 are located in the center of the reinforcement water stop ring 8. The top of the last section of the steel pipe 13 is provided with an injection port 14 and an overflow port 15. The injection port 14 and the overflow port 15 are located inside the subway station, and multiple water-swellable water stop rings 16 are provided on the inner wall of the last section of the steel pipe 13. The last section of the steel pipe 13 is also filled with foam concrete 17.

[0053] The jacking length of the steel pipe 13 and the annular steel blade 3 is greater than the length of the shield machine, and the diameter of the steel pipe 13 is greater than the outer diameters of the shield machine and the shield tunnel lining.

Claims

1. A construction method for the exit of a shield machine receiving a steel pipe jacked into a subway station in silt geological conditions, characterized in that, It includes the following construction steps: Step 1. Reserve the annular steel blade and conduit openings: When constructing the receiving side wall (1) of the shield machine in the subway station, reserve the annular steel blade (3); and reserve a plurality of conduit openings (2) outside the annular steel blade (3), and temporarily seal the conduit openings (2). Step 2. Construct grouting holes to reinforce the water stop ring: Drill through the silty soil layer (5) through the conduit openings (2) to form grouting holes (7); perform high-pressure grouting on the grouting holes (7) to form a reinforced water stop ring (8). Step 3. Freezing construction at the ring opening: The freezing equipment (9) freezes the silty soil at the ring opening of the reinforced water stop ring (8) through the freezing pipes (10) to form a temporary freezing zone (11). Step 4. Layout the jacking system: Demolish part of the supporting structure (4) surrounded by the annular steel blade (3); layout the jacking system (12) on the subway station floor (6) inside the receiving side wall (1). Step 5. Gradually jack in the steel pipes in segments: Place the steel pipe (13) into the jacking system (12), weld and seal the steel pipe (13) and the annular steel blade (3), and then use the jacking system (12) to jack the steel pipe (13) and the annular steel blade (3) into the reinforced water stop ring (8); weld and seal the subsequent section of the steel pipe (13) with the already jacked-in steel pipe (13) and then jack it into the reinforced water stop ring (8); there are an injection port (14) and an overflow port (15) at the top of the last section of the steel pipe (13). Step 6. Inject foamed concrete into the steel pipe: Demolish the jacking system (12), seal the tail end of the steel pipe (13), pour foamed concrete (17) through the injection port (14) until the overflow port (15) is full; remove the seals at the outer ends of the steel pipe (13), the freezing equipment (9) and the freezing pipes (10). When implementing Steps 4 to 6, the freezing equipment (9) freezes the silty soil at the ring opening of the reinforced water stop ring (8) again through the freezing pipes (10) to keep the temporary freezing zone (11) at the ring opening position of the reinforced water stop ring (8) in the silty soil layer (5) in a frozen state.

2. The construction method for the shield machine to exit the tunnel by jacking steel pipes in the subway station on silty soil according to claim 1, characterized in that, In Step 1: The outer diameter of the annular steel blade (3) is equal to the outer diameter of the jacking steel pipe (13), and the wall thickness of the annular steel blade (3) is twice that of the jacking steel pipe (13); the rear end of the annular steel blade (3) is welded to the jacking steel pipe (13); the length of the annular steel blade (3) is equal to twice the thickness of the receiving side wall (1), the front end of the annular steel blade (3) is located at the outer edge of the receiving side wall (1), and the rear end of the annular steel blade (3) is inside the subway station, showing a rabbet shape; the length of the conduit opening (2) is the sum of the thickness of the receiving side wall (1) and the thickness of the supporting structure (4), the outer end of the conduit opening (2) is flush with the outer edge of the supporting structure (4), and the inner end of the conduit opening (2) is flush with the inner edge of the receiving side wall (1); the inclination angle of the conduit opening (2) is controlled at 2 - 4°.

3. The construction method for the shield machine to exit the tunnel by jacking steel pipes in the subway station on silty soil according to claim 1, characterized in that The hole size and inclination angle of the grouting hole (7) are the same as those of the conduit opening (2), and the horizontal length of the reinforced water stop ring (8) is greater than the sum of the jacking length of the steel pipe (13), the length of the annular steel blade (3) and the diameter of the steel pipe (13).

4. The construction method for the shield machine to exit the tunnel by jacking steel pipes inside the subway station in silt geological conditions according to claim 1, characterized in that, In Step 5: The injection port (14) and the overflow port (15) of the last section of the steel pipe (13) are located inside the subway station, and a plurality of water-swellable waterstops (16) are provided on the inner wall of the outermost section of the steel pipe (13).

5. The construction method for the shield machine to exit the tunnel by jacking a steel pipe in a silty soil geological subway station according to claim 1, characterized in that, In Step 5: The jacking lengths of the steel pipe (13) and the annular steel blade (3) are greater than the length of the shield machine, and the diameter of the steel pipe (13) is greater than the outer diameters of the shield machine and the lining of the shield tunnel.

6. The construction method for the shield machine to exit the tunnel by jacking steel pipes in the silt geological subway station according to claim 1, characterized in that, Step 6 specifically includes: removing the jacking system (12), cleaning the partially loose silt layer (5) outside the steel pipe (13), then sealing the tail end of the steel pipe (13), pouring foam concrete (17) with the same strength as the silt layer (5) inside the steel pipe (13) through the injection port (14) on the steel pipe (13), and stopping the pouring when the overflow port (15) is full; after the foam concrete (17) solidifies and hardens, removing the seal at the outer end of the steel pipe (13), the freezing equipment (9) on the ground, and the freezing pipes (10) at the ring opening, completing the structure for receiving the shield machine to exit the tunnel by jacking the steel pipe (13) inside the subway station with silty soil, so as to receive the shield machine for the operation of exiting the tunnel.

Images