1. The utility model provides an originating tunnel entrance to a cave seal structure for balanced shield of muddy water which characterized in that: including first way seal ring (1), two seal ring (2), tail end seal ring (3) and hole door ring (4), the outside of working well inside lining (8) is fixed in hole door ring (4), first way seal ring (1) the upper end of two seal ring (2) respectively with hole door ring (4) are connected, first way seal ring (1) is located tunnel entrance to a cave department, two seal ring (2) are located first way seal ring (1) outside, tail end seal ring (3) are located two seal ring (2) outsides and with the end connection of hole door ring (4).

2. The initial tunnel portal sealing structure for the slurry balance shield according to claim 1, characterized in that: the upper end of the first water stop ring (1) and the upper end of the second water stop ring (2) are welded and fixed with the lower end face of the hole door ring (4), the outer end of the hole door ring (4) is welded and fixed with the upper portion of the tail end water stop ring (3), the lower end of the first water stop ring (1), the second water stop ring (2) and the tail end water stop ring (3) is located on the door sealing lining (6).

3. The initial tunnel portal sealing structure for the slurry balance shield according to claim 2, characterized in that: the primary water stop ring (1) comprises a primary flexible water stop plate (11), a primary first circular plate (12), a primary second circular plate (13), a primary pin shaft (14) and a primary turning plate (15), wherein the two sides of the upper part of the primary flexible water stop plate (11) are respectively wrapped and clamped by the primary first circular plate (12) and the primary second circular plate (13), the lower end of the primary second circular plate (13) is rotatably connected with the primary turning plate (15) through the primary pin shaft (14), and the primary turning plate (15) is located on the outer side of the lower part of the primary flexible water stop plate (11).

4. The initial tunnel portal sealing structure for the slurry balance shield according to claim 3, characterized in that: the primary water stop ring (1) further comprises a primary connecting bolt (16) and a primary inner side stiffening plate (17), the primary connecting bolt (16) penetrates through the primary first circular plate (12), the upper portion of the primary flexible water stop plate (11) and the primary second circular plate (13) to be locked, the primary inner side stiffening plate (17) is arranged between the outer side of the primary second circular plate (13) and the lower end of the hole door ring (4), and the primary inner side stiffening plate (17) is vertically connected with the primary second circular plate (13) and the hole door ring (4).

5. The initial tunnel portal sealing structure for the slurry balance shield according to claim 3, characterized in that: the two water stop rings (2) comprise two flexible water stop plates (21), two first circular ring plates (22), two second circular ring plates (23), two pin shafts (24) and two turning plates (25), two sides of the upper portion of the two flexible water stop plates (21) are respectively wrapped and clamped by the two first circular ring plates (22) and the two second circular ring plates (23), the lower ends of the two second circular ring plates (23) are rotatably connected with the two turning plates (25) through the two pin shafts (24), and the two turning plates (25) are located on the outer sides of the lower portions of the two flexible water stop plates (21).

6. The initial tunnel portal sealing structure for the slurry balance shield according to claim 5, wherein: the two water stop rings (2) further comprise two connecting bolts (26) and two inner side stiffening plates (27), the two connecting bolts (26) penetrate through the two first circular ring plates (22), the upper parts of the two flexible water stop plates (21) and the two second circular ring plates (23) to be locked, the outer sides of the two second circular ring plates (23) and the lower ends of the hole door rings (4) are provided with the two inner side stiffening plates (27), and the two inner side stiffening plates (27) are perpendicularly connected with the two second circular ring plates (23) and the hole door rings (4).

7. The initial tunnel portal sealing structure for the slurry balance shield according to claim 5, wherein: the primary flexible water stop plate (11) and the secondary flexible water stop plate (21) are made of cord fabric rubber plates.

8. The initial tunnel portal sealing structure for the slurry balance shield according to claim 5, wherein: tail end seal ring (3) welded connection be in the outer end of entrance door ring (4), entrance door ring (4) welded fastening is in pre-buried steel sheet (81) of working well, tail end seal ring (3) is the loop configuration who adopts the steel sheet material to make, entrance door ring (4) is the tubular structure who adopts the steel sheet material to make.

9. The initial tunnel portal sealing structure for the slurry balance shield according to claim 8, characterized in that: the tail end water stop ring (3) is formed by splicing a plurality of large and small fan-shaped steel plates into a circular ring; seal door lining (6) including pre-buried outside steel sheet (61) and lining cutting (62), pre-buried outside steel sheet (61) are the arc steel sheet, the length of pre-buried outside steel sheet (61) with the length of lining cutting (62) equals.

10. A construction method of the sealing structure of the initial tunnel hole of the slurry balance shield according to any one of claims 1 to 9, comprising the following steps:

step a), carrying out foundation reinforcement on a tunnel portal, synchronously assembling a shield machine, using a working well embedded steel plate (81) of a working well lining (8) as a welding working surface, welding and installing a portal ring (4) on the outer side of the working well embedded steel plate (81), and welding and connecting a portal stiffening plate (5) between the upper end surface of the portal ring (4) and the working well embedded steel plate (81);

b), based on the door ring (4), installing a primary water stop ring (1) and a secondary water stop ring (2) at the lower end of the door ring;

c), manually breaking the enclosure structure after the reinforced soil body (9) reaches the design strength and the end falls to a position 1m below the tunnel portal, after the shield tunneling machine is debugged, assembling the negative ring to advance forwards, and enabling the cutter head to lean against the reinforced soil body (9);

d), pressurizing and building a slurry chamber of the shield tunneling machine through a separation chamber formed by the primary water stop ring (1) and the secondary water stop ring (2), and tunneling the shield tunneling machine forwards to assemble duct pieces (7);

step e), after the door sealing lining (6) is separated from the shield tail, arranging a tail end water stop ring (3) on the outer side of the door sealing ring (4), welding the tail end water stop ring (3) with the door sealing ring (4) and an embedded outer side steel plate (61) of the door sealing lining (6), performing secondary grouting through a pipe piece secondary grouting hole adjacent to the working well lining (8) and the reinforced soil body (9), and stopping precipitation after the door sealing ring (4) is sealed;

and f), continuously and circularly tunneling the assembled duct pieces (7) by the shield tunneling machine.

Background

In the field of civil engineering quantity, tunnel excavation is often carried out by adopting a shield machine which can be divided into a hand-excavation type shield, an extrusion type shield, a semi-mechanical type shield and a mechanical type shield, and the mechanical type shield is used more in cities. The mechanical shield can be divided into an air pressure type shield, a slurry balance shield, an earth pressure balance shield, a mixed type shield and the like. The slurry balance shield is a shield machine for balancing the water and soil pressure of the tunnel face by controlling the pressure of a slurry cabin, is suitable for geological conditions with large underground water pressure and large soil body permeability coefficient, and is widely used for construction of highway and railway tunnels crossing rivers, sea and the like.

For a slurry balance shield, when starting tunneling, because the slurry cabin pressure needs to be maintained, the sealing performance of the tunnel portal needs to be designed separately, and 1 or 2 curtain cloth rubber plates are usually adopted for water stopping. However, as the curtain cloth rubber plate is made of flexible material, when the pressure of the slurry cabin is higher, the phenomena of water seepage and slurry leakage at the hole can still occur, and the water seepage and slurry leakage can cause the slurry pressure to be reduced, thereby being not beneficial to the starting and the tunneling of the shield.

When the slurry balance shield starts to dig, the sealing performance of the opening is difficult to process properly, and the slurry pressure cannot reach the design pressure, so that the starting digging efficiency is limited. On the other hand, due to the problem of the sealing property of the opening, the water-rich stratum needs to be matched with long-time precipitation so as to ensure the tunneling safety of the shield tunneling machine and prevent underground water from rushing into the starting working well from the space between the duct piece and the stratum to cause casualties and property loss.

Based on the above, it is needed to provide an initial tunnel portal sealing structure and a construction method for a slurry balance shield, which can solve the problem of sealing performance of the slurry balance shield initiated at the tunnel portal.

Disclosure of Invention

The invention aims to provide a sealing structure for an initial tunnel portal of a slurry balance shield and a construction method, wherein the sealing structure is used for improving the sealing performance.

In order to achieve the purpose, the initial tunnel portal sealing structure for the slurry balance shield comprises a primary water stop ring, a secondary water stop ring, a tail end water stop ring and a portal ring, wherein the portal ring is fixed on the outer side of a working well lining, the upper ends of the primary water stop ring and the secondary water stop ring are respectively connected with the portal ring, the primary water stop ring is positioned at the tunnel portal, the secondary water stop ring is positioned on the outer side of the primary water stop ring, and the tail end water stop ring is positioned on the outer side of the secondary water stop ring and connected with the tail end of the portal ring.

In the technical scheme, the upper ends of the primary water stop ring and the secondary water stop ring are welded and fixed with the lower end face of the opening door ring, the outer end of the opening door ring is welded and fixed with the upper part of the tail water stop ring, and the lower ends of the primary water stop ring, the secondary water stop ring and the tail water stop ring are positioned on the sealing door lining.

In the technical scheme, the primary water stop ring comprises a primary flexible water stop plate, a primary first circular plate, a primary second circular plate, a primary pin shaft and a primary turning plate, two sides of the upper part of the primary flexible water stop plate are respectively wrapped and clamped by the primary first circular plate and the primary second circular plate, the lower end of the primary second circular plate is rotatably connected with the primary turning plate through the primary pin shaft, and the primary turning plate is positioned on the outer side of the lower part of the primary flexible water stop plate.

In the above technical scheme, the first water stop ring further includes a first connecting bolt and a first inner stiffening plate, the first connecting bolt penetrates through the first circular plate, the upper portion of the first flexible water stop plate and the first second circular plate to be locked, the first inner stiffening plate is arranged between the outer side of the first second circular plate and the lower end of the door ring, and the first inner stiffening plate is vertically connected with the first second circular plate and the door ring.

In the above technical scheme, the two water-stopping rings include two flexible water-stopping plates, two first circular ring plates, two second circular ring plates, two hinge pins and two turning plates, two sides of the upper portion of the two flexible water-stopping plates are respectively sandwiched by the two first circular ring plates and the two second circular ring plates, the lower ends of the two second circular ring plates are rotatably connected with the two turning plates through the two hinge pins, and the two turning plates are located on the outer sides of the lower portions of the two flexible water-stopping plates.

In the above technical scheme, the two water stop rings further include two connecting bolts and two inner side stiffening plates, the two connecting bolts penetrate through the two first circular ring plates, the upper portions of the two flexible water stop plates and the two second circular ring plates to be locked, the two inner side stiffening plates are arranged between the outer sides of the two second circular ring plates and the lower ends of the hole door rings, and the two inner side stiffening plates are vertically connected with the two second circular ring plates and the hole door rings.

In the above technical scheme, the primary flexible water stop plate and the secondary flexible water stop plate are made of cord fabric rubber plates.

In the technical scheme, the tail end water stop ring is connected to the outer end of the opening door ring in a welded mode, the opening door ring is fixedly welded to the embedded steel plate of the working well, the tail end water stop ring is of an annular structure made of steel plate materials, and the opening door ring is of a cylindrical structure made of steel plate materials.

In the technical scheme, the tail end water stop ring is formed by splicing a plurality of large and small fan-shaped steel plates into a circular ring; the door sealing lining comprises a pre-buried outer side steel plate and a lining, the pre-buried outer side steel plate is an arc-shaped steel plate, and the length of the pre-buried outer side steel plate is equal to that of the lining.

In order to achieve the purpose, the construction method of the sealing structure of the initial tunnel portal for the slurry balance shield comprises the following steps:

step a), carrying out foundation reinforcement on a tunnel portal, synchronously assembling a shield machine, using a working well embedded steel plate of a working well lining as a welding working surface, welding and installing a portal ring on the outer side of the working well embedded steel plate, and welding and connecting a portal stiffening plate between the upper end surface of the portal ring and the working well embedded steel plate;

b), based on the door ring, mounting a primary water stop ring and a secondary water stop ring at the lower end of the door ring;

c), manually breaking the enclosure structure after the reinforced soil body reaches the design strength and the end falls to a position 1m below the tunnel portal, after the shield tunneling machine is debugged, pushing the assembled negative ring forward, and enabling the cutter head to lean against the reinforced soil body;

d), pressurizing and building a slurry chamber of the shield tunneling machine through a separation chamber formed by the primary water stop ring and the secondary water stop ring, and tunneling the shield tunneling machine forwards to assemble duct pieces;

step e), after the door sealing lining is separated from the shield tail, arranging a tail end water stopping ring at the outer side of the hole door ring, welding the tail end water stopping ring with the hole door ring and a pre-buried outer side steel plate of the door sealing lining, performing secondary grouting through a segment secondary grouting hole adjacent to the working well lining and the reinforced soil body, and stopping precipitation after the hole door ring is sealed;

and f), continuously and circularly tunneling the assembled duct pieces by the shield tunneling machine.

The invention has the beneficial effects that: according to the initial tunnel portal sealing structure and the construction method for the slurry balance shield, two flexible closed bins are formed by the primary water stop ring and the secondary water stop ring, so that the problems of water seepage and slurry leakage of a portal during the initial of the slurry balance shield are prevented to a certain extent; a third rigid closed bin is formed by the tail end water stop ring, so that a complete closed space is formed, and the problems of water seepage and slurry leakage of a tunnel portal are effectively solved. The third sealed bin is a rigid sealed bin, so that high water pressure can be borne, the dewatering measures can be ended in advance, and the project amount is saved; meanwhile, the muddy water pressure is increased to the design pressure, the risk of bin explosion is avoided, and the starting tunneling reliability and safety are greatly improved.

Drawings

FIG. 1 is a schematic structural view of an installation section of a sealing structure of an originating tunnel portal for a slurry balance shield according to the present invention;

fig. 2 is a schematic construction diagram of an initial tunnel portal sealing structure for the slurry balance shield in fig. 1.

The components in the figures are numbered as follows: a primary water stop ring 1 (wherein, a primary flexible water stop plate 11, a primary first circular plate 12, a primary second circular plate 13, a primary pin 14, a primary turning plate 15, a primary connecting bolt 16 and a primary inner side stiffening plate 17); two water stop rings 2 (wherein, two flexible water stop plates 21, two first circular ring plates 22, two second circular ring plates 23, two pin shafts 24, two turning plates 25, two connecting bolts 26 and two inner side stiffening plates 27); a tail end water stop ring 3; a door ring 4; a hole stiffening plate 5; a door sealing lining 6 (wherein, an outer steel plate 61 and a lining 62 are pre-buried); a duct piece 7; a working well lining 8 (wherein, a working well embedded steel plate 81 and a lining 82); the soil mass 9 is reinforced.

Detailed Description

The invention is described in further detail below with reference to the figures and the specific embodiments.

Based on the problem that the sealing performance of the tunnel portal of the slurry balance shield starting in the prior art is not enough, the application provides a sealing structure and a construction method of the starting tunnel portal for the slurry balance shield, and the sealing performance is improved.

Referring to fig. 1 and fig. 2 in combination, the initial tunnel portal sealing structure for a slurry balance shield according to the preferred embodiment of the present invention includes an initial water stop ring 1, a secondary water stop ring 2, a tail end water stop ring 3, and a portal ring 4, wherein the initial water stop ring 1, the secondary water stop ring 2, and the tail end water stop ring 3 are respectively welded to the portal ring 4. More specifically, the upper ends of the primary water stop ring 1 and the secondary water stop ring 2 are welded and fixed with the portal ring 4, and the upper part of the tail end water stop ring 3 is welded and fixed with the tail end of the portal ring 4.

The primary water stop ring 1 is positioned at the tunnel portal and forms a first closed bin with the inner working well lining 8, the portal ring 4 above and the door sealing lining 6 below. The second water stop ring 2 is positioned at the outer side of the primary water stop ring 1 and forms a second closed bin with the primary water stop ring 1 at the inner side, the portal ring 4 at the upper part and the sealing door lining 6 at the lower part. The tail end water stop ring 3 is positioned at the tail end of the tunnel portal sealing structure and forms a third closed bin with the two water stop rings 2 on the inner side, the portal ring 4 on the upper part and the sealing door lining 6 on the lower part.

Specifically, the primary water stop ring 1 comprises a primary flexible water stop plate 11, a primary first circular plate 12, a primary second circular plate 13, a primary pin 14, a primary turning plate 15, a primary connecting bolt 16 and a primary inner stiffening plate 17. The primary flexible water stop plate 11 extends downwards from the lower end face of the portal ring 4 above, and the height of the primary flexible water stop plate 11 is larger than the distance between the portal ring 4 and the door sealing lining 6. The two sides of the upper part of the primary flexible water stop plate 11 are respectively wrapped and clamped by the primary first circular plate 12 and the primary second circular plate 13, and the primary first circular plate 12, the upper part of the primary flexible water stop plate 11 and the primary second circular plate 13 are fixed together through the primary connecting bolt 16. The lower end of the first second circular ring plate 13 is connected with a first turning plate 15 through a first pin shaft 14, the first turning plate 15 can rotate around the first pin shaft 14 relative to the first second circular ring plate 13, the first turning plate 15 is positioned on the outer side of the lower part of the first flexible water stop plate 11, and the lower end of the first turning plate is positioned on the upper end surface of the door sealing lining 6. In order to enhance the connection strength between the first inner side stiffening plate 17 and the portal ring 4, a first inner side stiffening plate 17 is arranged between the outer side of the first second circular ring plate 13 and the lower end of the portal ring 4, and the first inner side stiffening plate 17 is vertically connected with the first second circular ring plate 13 and the portal ring 4.

The structure of the primary water stop ring 1 is the same, and the secondary water stop ring 2 comprises a secondary flexible water stop plate 21, a secondary first circular plate 22, a secondary second circular plate 23, a secondary pin shaft 24, a secondary turning plate 25, a secondary connecting bolt 26 and a secondary inner side stiffening plate 27. The two flexible water stop plates 21 extend out from the lower end surface of the portal ring 4 above the two flexible water stop plates 21 downwards, and the height of the two flexible water stop plates 21 is larger than the distance between the portal ring 4 and the door sealing lining 6. The two sides of the upper part of the two flexible water stop plates 21 are respectively fixed by two first circular ring plates 22 and two second circular ring plates 23, and the two first circular ring plates 22, the upper parts of the two flexible water stop plates 21 and the two second circular ring plates 23 are fixed together through two connecting bolts 26. The lower end of the second circular plate 23 is connected with a second turning plate 25 through a second pin shaft 24, the second turning plate 25 can rotate around the second pin shaft 24 relative to the second circular plate 22, the second turning plate 25 is positioned at the outer side of the lower part of the second flexible water stop plate 21, and the lower end of the second turning plate 25 is positioned on the upper end surface of the door sealing lining 6. In order to enhance the connection strength between the hole door ring 4 and the second circular ring plate 23, two inner side stiffening plates 27 are arranged between the outer sides of the second circular ring plates 23 and the lower ends of the hole door ring 4, and the second inner side stiffening plates 27 are vertically connected with the second circular ring plates 23 and the hole door ring 4.

In the illustrated embodiment, the primary flexible water stop plate 11 and the secondary flexible water stop plate 21 are made of cord rubber plates, and the inner diameter of the cord rubber plates is 5650mm, and the outer diameter of the cord rubber plates is 6390 mm.

The tail end water stop ring 3 is rigidly connected with the hole door ring 4 in a welding mode, and the tail end water stop ring 3 is connected to the outer end of the hole door ring 4. The upper part of the tail end water stop ring 3 is connected with the outer end of the portal ring 4, and the tail end water stop ring 3 is of an annular structure and is made of steel plate materials. The door ring 4 is a cylindrical structure and is made of steel plate materials.

The portal ring 4 is fixed on the working well lining 8, and more specifically, the front end of the portal ring 4 is welded and fixed on the working well embedded steel plate 81 of the working well lining 8. An opening stiffening plate 5 is arranged between the upper end of the opening door ring 4 and the working well embedded steel plate 81, and the opening stiffening plate 5 reinforces the connection strength between the opening door ring 4 and the working well embedded steel plate 81.

In the illustrated embodiment, the tail water stop ring 3 may be assembled into a circular ring by 6 equal-sized fan-shaped steel plates. The inner diameter of the tail end water stop ring 3 is 5800mm, the outer diameter of the tail end water stop ring is 6490mm, and the thickness of the tail end water stop ring is 10-20 mm. The aperture ring 4 has a thickness of 20 mm.

The door-sealing lining 6 is composed of an embedded outer steel plate 61 and a lining 62. The embedded outer steel plate 61 is an arc-shaped steel plate, the thickness of the embedded outer steel plate is 10-20 mm, and the length of the embedded outer steel plate 61 is equal to that of the lining 62.

The invention discloses a construction method of an initial tunnel portal sealing structure for a slurry balance shield, which comprises the following steps:

step a), carrying out foundation reinforcement on a tunnel portal, synchronously assembling a shield machine, using a working well embedded steel plate 81 of a working well lining 8 as a welding working surface, and installing a portal ring 4 and a portal stiffening plate 5;

step b), installing a primary water stop ring 1 and a secondary water stop ring 2 based on the door ring 4;

step c), when the reinforced soil body 9 reaches the design strength, manually breaking the enclosure structure after the end head falls to the position 1m below the tunnel portal, after the shield tunneling machine is debugged, pushing the assembled negative ring forward, and enabling the cutter head to lean against the reinforced soil body 9;

step d), smoothly pressurizing and building a shield slurry chamber through a compartment formed by the primary water stop ring 1 and the secondary water stop ring 2, driving the shield machine forwards, and assembling the duct piece 7;

and e), after the door sealing lining 6 is separated from the shield tail, arranging a tail end water stop ring 3, welding the tail end water stop ring 3 with the portal ring 4 and the pre-buried outer side steel plate 61, simultaneously carrying out secondary grouting through a lining 82 adjacent to the working well lining 8 and a segment secondary grouting hole of the reinforced soil body 9, sealing the portal ring 4, and then stopping precipitation.

And f), continuously and circularly tunneling the assembled duct pieces 7 by the shield tunneling machine.

According to the initial tunnel portal sealing structure and the construction method for the slurry balance shield, two flexible closed bins are formed by the primary water stop ring and the secondary water stop ring, so that the problems of water seepage and slurry leakage of a portal during the initial of the slurry balance shield are prevented to a certain extent; a third rigid closed bin is formed by the tail end water stop ring, so that a complete closed space is formed, and the problems of water seepage and slurry leakage of a tunnel portal are effectively solved. The third sealed bin is a rigid sealed bin, so that high water pressure can be borne, the dewatering measures can be ended in advance, and the project amount is saved; meanwhile, the muddy water pressure is increased to the design pressure, the risk of bin explosion is avoided, and the starting tunneling reliability and safety are greatly improved.

In conclusion, the initial tunnel portal sealing structure and the construction method for the slurry balance shield can effectively overcome the problems of water seepage and slurry leakage of the portal, avoid the risk of groundwater inrush into the initial working well, save the precipitation engineering quantity and improve the initial reliability and safety. In addition, the sealing structure and the construction method for the initial tunnel portal of the slurry balance shield are simple and flexible to operate, low in use cost and high in practicability.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.