Disclosure of Invention
The invention aims to solve the technical problems of providing a novel earth pressure balance shield and a working method thereof, wherein an earth cabin and an air cushion cabin are arranged and are stirred by a stirring rod, so that the advantages of the existing earth pressure balance shield and the existing slurry balance shield are integrated, and the novel earth pressure balance shield and the working method thereof are suitable for urban tunnel construction.
The aim of the invention is realized by the following technical scheme:
a novel earth pressure balance shield machine comprises a cutter head, a front shield, a middle shield, a human brake, a shield tail, a splicing machine, a main drive and a screw conveyor, wherein a front shield partition plate is arranged between the front shield and the middle shield, an intermediate partition plate is arranged in the front shield to divide a front shield space into two parts, the front part is an earth cabin, and the rear part is an air cushion cabin; the lower part of the middle partition plate is not closed; the cutter head is connected with a large gear ring of the main drive through a supporting arm;
A first gate, an air inlet and an air overflow port are arranged on the front shield partition plate, and a second gate is arranged on the personnel gate; the middle partition plate is provided with a passage door and a passive stirring rod; an active stirring rod is arranged behind the cutterhead; the first gate is arranged on the upper part of the front shield partition plate, and a slag conveying port is arranged on the lower part of the front shield partition plate.
As a preferable mode, two stirring rods are arranged at the upper part behind the cutter head, and two stirring rods are arranged at the lower part behind the cutter head; the stirring rod is positioned on the middle vertical line of the cutter head.
Preferably, the positions of the active stirring rods and the positions of the passive stirring rods are staggered.
Preferably, the screw conveyor comprises two sections, namely a first section screw conveyor and a second section screw conveyor; the first section of screw conveyor is obliquely arranged, and the front part of the first section of screw conveyor is positioned at the slag conveying port of the front shield partition plate; the second section of screw conveyor is horizontally arranged.
As a preferable mode, the splicing machine is used for splicing the duct piece, a pushing oil cylinder is arranged at the front end of the duct piece, the front part of the pushing oil cylinder is propped against the front shield baffle plate, and the rear part of the pushing oil cylinder is propped against the front end face of the duct piece.
Preferably, the first soil pressure sensor is mounted on the intermediate partition plate.
Preferably, a mud level gauge is mounted on the front shield partition.
Preferably, a second soil pressure sensor is arranged on the front shield partition plate, and the second soil pressure sensor is arranged at the lower part of the front shield partition plate.
Preferably, the front shield partition plate is provided with an air pressure sensor.
A working method of a novel earth pressure balance shield machine comprises the following steps:
The improved cutting step comprises the following steps: spraying slag soil improvement materials on the face in front of the cutterhead and improving slag soil cut by a cutter on the cutterhead; the high-pressure hydraulic oil drives the hydraulic motor and the speed reducer to rotate, so as to drive the main driving large gear ring to rotate, and finally the cutterhead to rotate; cutting front undisturbed soil by a cutter on the cutter disc, and enabling the undisturbed soil to enter a soil cabin and a lower space of the air cushion cabin;
The pushing step comprises the following steps: starting a propulsion oil cylinder, wherein the propulsion oil cylinder props against the front end surface of the duct piece to propel forwards; opening the screw conveyor gate, starting the second section screw conveyor and the first section screw conveyor to slag, and conveying the improved slag to the horizontal belt through the slag conveying port, the first section screw conveyor, the second section screw conveyor and the screw conveyor gate;
assembling: and stopping pushing after the shield machine is pushed for a certain distance, and sequentially assembling a plurality of segments of the ring of segments into a ring by adopting a segment assembling machine.
Preferably, in the propelling step, in order to achieve the required balance pressure, the soil chamber is filled with improved slurry, the space at the lower part of the air cushion chamber is filled with slurry, and the upper part of the air cushion chamber is provided with pressurized gas;
Comparing the actual soil pressure measured by the at least one soil pressure sensor with the theoretical equilibrium pressure, adding pressurized gas when the actual soil pressure is lower than the theoretical equilibrium pressure, and gradually increasing the pressure value of the gas entering the air cushion cabin through the gas inlet; when the actual soil pressure is equal to the theoretical equilibrium pressure, the air pressure value of the air inlet entering the air cushion cabin is maintained; when the actual soil pressure is greater than the theoretical equilibrium pressure, the air overflow port is opened, the air cushion cabin is deflated, the air pressure value of the air inlet entering the air cushion cabin is gradually reduced, and once the actual soil pressure is equal to the theoretical equilibrium pressure, the air overflow port is closed immediately.
The beneficial effects of the invention are as follows: the invention improves on the basis of the traditional earth pressure balance shield machine, is provided with the earth cabin and the air cushion cabin, and plays the advantages of the slurry balance shield. In addition, the stirring rod is further arranged, and the slag soil entering the earth cabin of the shield machine is stirred by the stirring rod, so that the fluidity of the slag soil is further increased, the combination of the earth pressure balance shield and the slurry balance shield is more reasonable, and the method has a wider popularization prospect.
Detailed Description
The technical solution of the present invention will be described in further detail with reference to the accompanying drawings, but the scope of the present invention is not limited to the following description.
In the description of the embodiments of the present invention, it should be noted that, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship conventionally put in place when the product of the present invention is used, or the orientation or positional relationship conventionally understood by those skilled in the art is merely for convenience of describing the present invention and simplifying the description, and is not indicative or implying that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used merely for distinguishing between descriptions and not for understanding as indicating or implying a relative importance.
Example 1
As shown in fig. 1 and 2, a novel earth pressure balance shield machine comprises a cutter head 1, a front shield 3, a middle shield 8, a human brake 9, a shield tail 13, a splicing machine 15, a main drive 24 and a screw conveyor, wherein a front shield partition plate 31 is arranged between the front shield 3 and the middle shield 8, a middle partition plate 28 is arranged in the front shield 3 to divide the space of the front shield 3 into two parts, a soil cabin 4 is arranged in the front, and an air cushion cabin 6 is arranged in the rear; the lower part of the middle partition plate 28 is not closed; the cutter head 1 is connected with a large gear ring of a main drive 24 through a supporting arm 23; a hinged seal 10 is arranged between the middle shield 3 and the shield tail 13.
The front shield baffle 31 is provided with a first gate 7, an air inlet 30 and an overflow 29, and the passenger gate 9 is provided with a second gate 12; the middle partition plate 28 is provided with an access door 5; the first gate 7 is disposed at an upper portion of the front shield partition 31, and a slag-conveying port 35 is disposed at a lower portion of the front shield partition 31.
The invention structurally improves the traditional earth pressure balance shield machine, and the middle partition plate 28 is arranged to form the earth chamber 4 and the air cushion chamber 6, so that the advantages of the traditional slurry balance shield are combined. In addition, the stirring rod is arranged, and the slag soil improvement is more facilitated by the action of the active stirring rod 2 and the passive stirring rod 26.
Example two
The first embodiment is similar to the first embodiment, except that the active stirring rod 2 is installed at the rear of the cutter head 1, and the passive stirring rod 26 is installed on the middle partition plate 28.
Or two stirring rods are arranged at the upper part behind the cutter head 1, and two stirring rods are arranged at the lower part behind the cutter head 1; the stirring rod is positioned on the middle vertical line of the cutter head 1. Along with the rotation of the cutter head 1, the active stirring rod 2 rotates in the soil bin 4 to stir the dregs in the soil bin 4, and a good stirring effect can be obtained.
As shown in fig. 1 and 2, the position of the active stirring bar 2 and the position of the passive stirring bar 26 are staggered. Generally speaking, the dregs are stirred by the active stirring rod 2 and then pushed to the passive stirring rod 26 for stirring, and the two stirring rods are matched with each other, so that resources are saved, and good stirring effect can be achieved.
When the active stirring rod 2 is arranged at the position of the center line behind the cutter head 1, two passive stirring rods 26 are respectively arranged at the left side and the right side of the middle partition plate 28. The left and right passive stirring bars 26 are symmetrically distributed along the center vertical line of the middle partition plate 28.
Example III
Conventional screw conveyors tend to be provided in only one stage, but due to the limited height of the shield machine, the distance of transport is often limited. The present invention provides a two-stage screw conveyor that can transport longer distances and ensure that the belt 22 is disposed horizontally.
The screw conveyor comprises two sections, namely a first section screw conveyor 16 and a second section screw conveyor 19; the first section of screw conveyor 16 is obliquely arranged, and the front part of the first section of screw conveyor 16 is positioned at a slag conveying port 35 of the front shield baffle plate 31; the second screw conveyor 19 is arranged horizontally. The first section screw conveyor 16 and the second section screw conveyor 19 may be connected by a spherical hinge 18 or a spherical joint, or may be connected by a rubber soft joint.
For the driving of the screw conveyor, it is possible to take the form of an endless drive, a first endless drive 17 being provided on a first section of screw conveyor 16 and a second endless drive 20 being provided on a second section of screw conveyor 19. The first annular drive 17 comprises a drive motor and a transmission device, wherein the drive motor drives the transmission device to rotate, and the transmission device drives the rotating shaft of the screw conveyor to rotate. The second endless drive 20 includes a drive motor and a transmission device, the drive motor drives the transmission device to rotate, and the transmission device drives the rotating shaft of the screw conveyor to rotate. The transmission device is a gear meshing mechanism. Of course, the screw conveyor may also be driven in the form of a driven, axially mounted drive motor. The annular driving device can obtain more installation space and transportation distance, and compared with an axially installed driving motor, the annular driving device is better in installation and transportation effects.
Example IV
For the driving of the whole shield machine or the front shield 3, the invention adopts the propulsion cylinder 11 for driving. The splicing machine 15 is used for splicing the duct piece 14, a pushing oil cylinder 11 is arranged at the front end of the duct piece 14, the front part of the pushing oil cylinder 11 is propped against the front shield baffle 31, and the rear part is propped against the front end face of the duct piece 14. The driving mode is simple, stable in operation and good in driving capability.
As shown in fig. 3, a first soil pressure sensor 27 is mounted on the intermediate partition plate 28, and the first soil pressure sensor 27 is used for detecting the pressure value of the slag. The first soil pressure sensors 27 are 4 in number and are uniformly disposed on the intermediate partition plate 28. The first soil pressure sensor 27 and the passive stirring rod 26 are alternately arranged in the circumferential direction of the intermediate partition plate 28. A mud level gauge is mounted on the front shield 31. The mud level gauge includes a first mud level gauge 32, a second mud level gauge 33, and a third mud level gauge 34. On the front shield 31, a third mud level gauge 34, a second mud level gauge 33 and a first mud level gauge 32 are arranged in order from bottom to top. A first mud level gauge 32, a second mud level gauge 33 and a third mud level gauge 34 are provided in the middle of the front shield 31. The front shield baffle 31 is provided with a second soil pressure sensor 38, and the second soil pressure sensor 38 is arranged at the lower part of the front shield baffle 31; the number of the second soil pressure sensors 38 is two and is distributed on both sides of the lower portion of the front shield partition plate 31. The front shield 31 is provided with an air pressure sensor 37, and the air pressure sensor 37 is provided on the upper portion of the front shield 31. A mud level travel sensor 36 (or level sensor) is provided on the front shield 31, and the actual position of the mud in the air cushion chamber 6 is directly read by the mud level travel sensor 36. A working method of a novel earth pressure balance shield machine comprises the following steps:
The improved cutting step comprises the following steps: opening a dregs improving system, spraying dregs improving materials on the face in front of the cutterhead 1, and improving dregs cut by a cutter on the cutterhead 1; the high-pressure hydraulic oil drives the hydraulic motor and the speed reducer 25 to rotate, so as to drive the large gear ring of the main drive 24 to rotate, and finally the cutterhead 1 rotates; the cutter on the cutter disc 1 cuts front undisturbed soil into the lower space of the soil cabin 4 and the air cushion cabin 6;
The novel earth pressure balance shield cuts undisturbed soil on the front face by a cutter on the cutter disc 1 along with the rotation of the cutter disc 1, and forms flowing soil with larger flowing state, low permeability and low internal friction angle by improving slag soil improving materials such as foam, bentonite slurry, polymer aqueous solution, water and the like.
For a slag modifying system, it requires an auxiliary channel to transport the modifying material, the auxiliary channel being made up of multiple segments. An inlet of an auxiliary channel (a foam inlet when foam is injected) is formed in a fixed part of the rotary joint of the shield machine, and an outlet of the auxiliary channel is formed in the cutter disc 1. The shield constructs quick-witted rotary joint fixed part and sets up first passageway, sets up the second passageway on the shield constructs quick-witted rotary joint rotary part, sets up the third passageway on the blade disc 1 baffle, sets up the fourth passageway on the support arm 23, sets up the auxiliary pipeline between third passageway and the fourth passageway. When carrying the shield dregs improvement material, such as foam, the medium enters from the auxiliary channel inlet of the shield machine rotary joint fixing part, then passes through the first channel, the second channel, the third channel, the auxiliary pipeline and the fourth channel, and finally is sprayed out from the auxiliary channel outlet on the cutter disc 1 to improve the dregs. The auxiliary channel can be provided with a plurality of inlets and/or outlets, or one auxiliary channel is correspondingly provided with a plurality of inlets and/or outlets. When a plurality of inlets are arranged, the medium is convenient to inject, the flow is large, and the pressure is high. When a plurality of outlets are arranged, the spray area is wide and the improvement range is wide. The improved slag soil is easier to stir in the soil cabin, the resistance is smaller, and the service life of the stirring device can be prolonged.
The pushing step comprises the following steps: starting a propulsion oil cylinder 11, wherein the propulsion oil cylinder 11 props against the front end face of the duct piece 14 to propel forward; opening the screw conveyer gate 21, starting the second section screw conveyer 19 and the first section screw conveyer 16 to slag, and enabling the improved slag to fall onto the horizontal belt 22 through the slag conveying port 35, the first section screw conveyer 16, the second section screw conveyer 19 and the screw conveyer gate 21 and be conveyed out through the horizontal belt 22; the belt 22 is transported onto a slag car or continuous belt 22 and finally carried away by a slag car or continuous belt 22 conveyor.
Assembling: after the shield machine advances a distance (generally the length of one segment 14), the advance is stopped, and a segment 14 assembling machine 15 is used to sequentially assemble a plurality of segments 14 of one ring of segments 14 into one ring. Tunneling and assembling are repeated after assembling is completed.
Example five
In the pushing step (in the shield tunneling process), in order to reach the required balance pressure, the soil chamber 4 is filled with improved slurry, the space at the lower part of the air cushion chamber 6 is filled with slurry, and the upper part of the air cushion chamber 6 is provided with pressurized gas;
The actual soil pressure measured by at least one soil pressure sensor (either the first soil pressure sensor 27 or the second soil pressure sensor 38) is compared with the theoretical equilibrium pressure, and the actual soil pressure may be selected from the values measured by one of the soil pressure sensors, and an average value or a highest value or a lowest value of a plurality of (including all) soil pressure sensors may be employed.
When the actual soil pressure is lower than the theoretical equilibrium pressure, adding pressurized gas, and gradually increasing the pressure value of the air entering the air cushion cabin 6 through the air inlet 30; when the actual soil pressure is equal to the theoretical equilibrium pressure, the air pressure value of the air inlet 30 entering the air cushion cabin 6 is maintained; when the actual soil pressure is greater than the theoretical equilibrium pressure, the overflow port 29 is opened for a short time, the air cushion chamber 6 is deflated, the air pressure value of the air inlet 30 entering the air cushion chamber 6 is gradually reduced, and once the actual soil pressure is equal to the theoretical equilibrium pressure, the overflow port 29 is closed.
The actual air pressure in the air cushion chamber 6 is measured by the air pressure sensor 37. The air pressure regulating precision value in the air cushion cabin 6 is 0.01bar, thereby ensuring that the soil pressure balance pressure control precision can reach 0.01bar.
The actual position of the mud in the air cushion chamber 6 is directly read by the mud level travel sensor 36. In the shield tunneling process, the slag discharging speed of the screw conveyor is adjusted in real time according to the mud position of the air cushion cabin 6, so that the mud liquid level in the air cushion cabin 6 is ensured to be between the first mud liquid level meter 32 and the second mud liquid level meter 33. When the slurry level is higher than the first slurry level gauge 32, the shield pushing is stopped, and the first section of screw conveyor 16 and the second section of screw conveyor 19 slag; when the mud liquid level is lower than the second mud liquid level meter 33, the shield machine alarms and reminds, and the slag discharging speed of the first section of screw conveyor 16 and the second section of screw conveyor 19 is reduced; when the mud level is lower than the third mud level gauge 34, the first section screw conveyor 16 and the second section screw conveyor 19 automatically stop tapping and close the screw conveyor gate 21 to continue tunneling. The opening and closing stroke control of the screw conveyor shutter 21 is required to be accurate and quick.
The improvement of the novel earth pressure balance shield slag soil is required to reach a flowing state, and the slump value is at least more than 25 cm; adding a certain amount of fine particles (such as bentonite slurry and the like) into the fine-particle-free shield tunneling stratum slag soil improvement material; because the slag is relatively thin, the belt 22 must be horizontally disposed with a depth (downwardly convex) in the middle to prevent the slag from spilling out.
When the novel earth pressure balance shield is constructed, the air pressure value of the air cushion cabin 6 can be properly adjusted according to the earth surface subsidence condition; the air pressure value of the air cushion cabin 6 is generally slightly higher than the soil pressure value in the soil cabin 4 (e.g. 0.02 bar) due to the reduced effect of the slag pressure transmission; when the air pressure value of the air cushion cabin 6 is far greater than the soil pressure value (such as 1 bar) in the soil cabin 4, the improvement of the slag soil is poor, and the improvement of the slag soil cut by the cutter is enhanced.
In conclusion, the invention has the advantages of small occupied area of the working well of the earth pressure balance shield, fast construction progress, low construction cost, accurate control of the earth pressure of the earth cabin of the slurry balance shield and small subsidence of the earth surface and the building. The front shield baffle 31 of the invention and the rear of the cutter head 1 are divided into two parts by a soil cabin baffle (middle baffle 28), the soil cabin 4 is arranged in front of the middle baffle 28, and the air cushion cabin 6 is arranged behind the middle baffle 28. Along with the rotation of the cutterhead 1, the cutter on the cutterhead 1 cuts undisturbed soil on the front face, and the undisturbed soil is modified by slag soil modifying materials such as foam, bentonite slurry, polymer water solution, water and the like to form mobile soil with a large flowing state, low permeability and low internal friction angle. The mobile soil enters the soil chamber 4 through the opening of the cutter disc 1, and fills the whole soil chamber 4 and the lower space of the air cushion chamber 6. The upper space of the air cushion cabin 6 is filled with pressurized air which is controlled and regulated by a soil cabin pressure control system (such as 2 electric air compressors with power of 45 KW). The mobile soil is rotationally conveyed onto a horizontal belt 22 through a double-screw conveyor, is conveyed to the tail part of a shield trolley through the horizontal conveying belt 22, directly falls into a slag car, is finally conveyed to a working well through a battery car, is lifted to the ground through a gantry crane, is poured into a slag pit, and is then carried away through loading of an excavator. The mobile earth can also be conveyed by a double screw conveyor onto a horizontal belt 22 and conveyed by a continuous belt 22 to a shield work wellhead and by a vertical belt 22 to the ground for disposal.
The foregoing description of the preferred embodiment of the invention is not intended to be limiting, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.