CN219711537U - Mortar reinforcing device and mortar reinforcing system of shield tunnel - Google Patents

Abstract

The utility model relates to the technical field of subway shield construction, in particular to a mortar reinforcing device and a mortar reinforcing system of a shield tunnel, wherein the mortar reinforcing device of the shield tunnel comprises: the first extension ring is used for being connected between the tunnel portal steel ring and the grout stop plate, the grouting ball valve is arranged on the first extension ring, and the grouting ball valve is used for injecting first quick setting grout into the cavity behind the duct piece wall; the grouting system can penetrate through the duct piece and inject second-speed coagulating slurry into the cavity behind the duct piece wall. The grouting ball valve on the first extension ring is used for injecting first quick setting slurry into the cavity behind the pipe piece wall, and simultaneously the grouting system is used for injecting second quick setting slurry into the cavity behind the pipe piece wall, so that when the station is positioned in a water-rich stratum, the quick setting slurry is injected into the cavity behind the upper part of the pipe piece wall through the first extension ring and the grouting system, and then the cavity behind the upper part of the compact pipe piece wall is filled, water, mud and sand are prevented from flowing out outwards through the cavity behind the pipe piece wall, a tunnel portal structure is protected, and shield construction safety is further protected.

Description

Mortar reinforcing device and mortar reinforcing system of shield tunnel

Technical Field

The utility model relates to the technical field of subway shield construction, in particular to a mortar reinforcing device and a mortar reinforcing system for a shield tunnel.

Background

The shield method is a fully mechanized construction method in the construction of the undermining method, which is a mechanized construction method for pushing shield machinery in the ground, preventing collapse in a tunnel from happening through surrounding rocks around a shield shell and a duct piece support, excavating soil in front of an excavating face by a cutting device, transporting out of the tunnel through an earth-discharging machine, pressurizing and jacking at the rear part by a jack, and splicing precast concrete duct pieces to form a shield tunnel structure.

In the shield tunneling process, because the outer diameter of the segment is smaller than the outer diameter of a cutterhead and a shield shell of the shield tunneling machine, an annular gap exists between the outer side of the segment and a stratum after the segment is separated from the shield tail, if the segment cannot be filled effectively, the ground surface is extremely easy to subside greatly, and even the ground building collapses, so that a portal steel ring and a slurry stopping plate are installed on the outer wall of the segment at the extreme end in the shield tunneling machine operation process, the end part of a gap area behind the segment wall is sealed, then mortar is injected into the gap area behind the segment wall, and in general, a synchronous grouting mode is adopted, namely, the synchronous grouting is performed through a synchronous grouting system and a grouting pipe of the shield tail during tunneling, mortar is injected into the gap area while the shield is pushed forward by the shield, and the mortar plays a role of filling in the gap area of the shield tail, so that surrounding soil is supported timely, and the slumping of the ground surface can be effectively prevented.

In shield construction operation, the mortar setting time that shield constructs quick-witted synchronous injection is longer, lead to partial mortar to run off from the gap between end pulp board and the section of jurisdiction for the space area upper portion behind the section of jurisdiction wall can't fill closely knit completely, lead to leaving the cavity on the upper portion behind the section of jurisdiction wall, in daily operation, above-mentioned cavity behind the section of jurisdiction wall is less to construction and later maintenance influence, negligible, but when the station is located rich water stratum, water in the stratum, mud, sand etc. easily gushes into cavity behind the section of jurisdiction wall and overflow from the gap between end pulp board and the section of jurisdiction, lead to the cavity between section of jurisdiction outside and the stratum soil body to enlarge the formation cavity because of water, mud, sand etc. overflow in the stratum soil body and enlarge behind the reduction, and stratum cavity department very easily takes place to collapse, easily produce the problem of geological collapse risk.

Disclosure of Invention

The utility model aims at: the mortar reinforcing device and the mortar reinforcing system for the shield tunnel are provided, wherein the mortar reinforcing device and the mortar reinforcing system are used for solving the problems that when a station is positioned in a water-rich stratum, water, mud and sand in stratum soil easily flow into a cavity behind the segment wall and overflow from a gap between the slurry stopping plate and the segment, so that the cavity between the outside of the segment and the stratum is enlarged to form a cavity after overflow of water, mud, sand and the like in the stratum is reduced, collapse is extremely easy to occur at the cavity of the stratum, and geological collapse risks are easy to occur.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows:

a mortar reinforcing apparatus for a shield tunnel, comprising:

the first extension ring is used for being connected between the portal steel ring and the grout stop plate, the first extension ring is provided with a grouting ball valve, and the grouting ball valve is used for injecting first quick setting grout into the cavity behind the duct piece wall;

the grouting system can penetrate through the duct piece and inject second-speed coagulating slurry into the cavity behind the duct piece wall.

According to the mortar reinforcing device for the shield tunnel, the first extension ring and the grouting system are arranged, when the mortar synchronously injected into the shield machine is longer in solidification time, so that part of mortar runs off from a gap between the mortar stopping plate and the pipe piece and cannot fill the cavity at the rear upper part of the wall of the compact pipe piece, the first quick-setting mortar is injected into the cavity at the rear part of the wall of the pipe piece through the grouting ball valve on the first extension ring, and the second quick-setting mortar is injected into the cavity at the rear part of the wall of the pipe piece through the grouting system, so that the quick-setting mortar can be quickly filled into the cavity at the rear upper part of the wall of the pipe piece, the quick-setting mortar is injected into the cavity at the rear upper part of the wall of the pipe piece through the first extension ring and the grouting system when the station is positioned in a water-rich stratum, the cavity at the rear upper part of the wall of the compact pipe piece is further filled, water, the cement and sand are prevented from flowing out through the cavity at the rear part of the wall of the pipe piece, and the tunnel gate structure is protected, and the construction safety is further protected.

As a preferable mode of the utility model, the grouting ball valves are arranged at intervals on the upper part of the first extension ring.

As a preferable scheme of the utility model, the number of the grouting ball valves is not less than 6, and the included angle between adjacent grouting ball valves is theta, wherein the included angle theta is 20 degrees.

As a preferable scheme of the utility model, the included angle between the grouting ball valve and the vertical central line of the first extension ring at the farthest position is alpha, wherein the included angle alpha is 50 degrees.

As a preferable scheme of the utility model, the grouting system comprises a communicating pipe, wherein the communicating pipe is arranged on the pipe piece and is communicated with the cavity behind the pipe piece wall.

As a preferable scheme of the utility model, the grouting system further comprises a three-fork mixing device and a double-liquid grouting device, wherein the three-fork mixing device comprises two input pipes and a mixing pipe, the two input pipes are communicated with the mixing pipe, the double-liquid grouting device comprises two groups of slurry output ports, each group of slurry output ports are communicated with one input pipe, and the mixing pipe is communicated with the communicating pipe.

As a preferable scheme of the utility model, the grouting system further comprises a working platform, wherein the working platform is used for installing the grouting system.

As a preferable mode of the utility model, the working platform is erected along the axial direction of the duct piece.

The utility model also discloses a mortar reinforcing system, which comprises a tunnel portal steel ring, a grout stopping plate, a duct piece and the mortar reinforcing device for the shield tunnel, wherein the grout stopping plate comprises a fan-shaped pressing plate and an annular sealing piece, the fan-shaped pressing plate is used for fixing the annular sealing piece, the annular sealing piece is abutted with the duct piece, and a fixed annular plate is further arranged between the fan-shaped pressing plate and the annular sealing piece.

According to the mortar reinforcing system, the gap between the first extension ring and the duct piece is sealed through the mortar stopping plate, mortar on the wall of the duct piece is prevented from overflowing, the effect of sealing the mortar is achieved, the cavity with the wall thickness of the duct piece is filled compactly through the mortar reinforcing device of the shield tunnel, and the reinforcement of the mortar is achieved through the cooperative cooperation of the tunnel portal steel ring, the mortar stopping plate, the duct piece and the mortar reinforcing device, so that the tunnel portal structure is protected, and the shield operation safety is further protected.

As a preferable scheme of the utility model, a bending part is arranged on one side of the annular sealing element, which is close to the duct piece, and the bending part is abutted against the duct piece.

In summary, due to the adoption of the technical scheme, the beneficial effects of the utility model are as follows:

1. according to the mortar reinforcing device for the shield tunnel, the first extension ring and the grouting system are arranged, when the mortar synchronously injected into the shield machine is longer in solidification time, so that part of mortar runs off from a gap between the mortar stopping plate and the pipe piece and cannot fill the dense pipe piece wall rear cavity, the first quick setting slurry is injected into the pipe piece wall rear cavity through the grouting ball valve on the first extension ring, meanwhile, the second quick setting slurry is injected into the pipe piece wall rear cavity through the grouting system, so that the quick setting slurry fills the pipe piece wall rear cavity quickly, the effect of quickly plugging the pipe piece wall rear cavity is achieved, when a station is located in a water-rich stratum, the quick setting slurry is injected into the pipe piece wall rear cavity through the first extension ring and the grouting system, the dense pipe piece wall rear cavity is filled, water, mud and sand are prevented from flowing out through the pipe piece wall rear cavity and outwards, a tunnel portal structure is protected, and shield construction safety is further protected.

2. According to the mortar reinforcing system, the gap between the first extension ring and the duct piece is sealed through the mortar stopping plate, mortar on the wall of the duct piece is prevented from overflowing, the effect of sealing the mortar is achieved, the cavity with the wall thickness of the duct piece is filled compactly through the mortar reinforcing device of the shield tunnel, and the reinforcement of the mortar is achieved through the cooperative cooperation of the tunnel portal steel ring, the mortar stopping plate, the duct piece and the mortar reinforcing device, so that the tunnel portal structure is protected, and the shield operation safety is further protected.

Drawings

Fig. 1 is a schematic structural view of the present utility model.

Fig. 2 is a partial enlarged view at a of fig. 1.

Fig. 3 is a schematic view of the arrangement of the grouting ball valve of the utility model on the first extension ring.

Fig. 4 is a simplified view of fig. 2.

Fig. 5 is a schematic diagram of the cooperation of the grout stop plate and the duct piece of the present utility model.

Fig. 6 is a partial enlarged view at D of fig. 5.

Fig. 7 is a partial enlarged view at B of fig. 1.

Fig. 8 is a cross-sectional view at C-C of fig. 1.

Description of the drawings: 1-slurry stopping plate, 11-fan-shaped pressing plate, 12-fixed ring plate, 13-pin shaft, 14-fan-shaped turning plate, 15-annular sealing piece, 151-bending part, 16-connecting bolt, 2-first extending ring, 21-slurry injection ball valve, 3-portal steel ring, 4-anchoring steel bar, 5-slurry injection system, 51-trigeminal mixing device, 511-input pipe, 512-mixing pipe, 52-double-liquid grouting equipment, 53-rubber hose, 54-ball valve, 55-communicating pipe, 6-segment, 61-segment grouting hole, 7-station structure, 9-mortar, 10-soil body, 100-operation platform and 110-tunnel.

Detailed Description

The present utility model will be described in detail with reference to the accompanying drawings.

The present utility model will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present utility model more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

Example 1

As shown in fig. 1 and 2, a mortar reinforcing apparatus for a shield tunnel according to this embodiment includes:

the first extension ring 2 is used for being connected between the portal steel ring 3 and the grout stop plate 1, the first extension ring 2 is provided with a grouting ball valve 21, and the grouting ball valve 21 is used for injecting first quick setting grout into the cavity behind the wall of the duct piece 6;

the grouting system 5 can penetrate through the pipe piece 6 and inject second-speed coagulation slurry into the cavity behind the wall of the pipe piece 6.

According to the mortar reinforcing device for the shield tunnel, the first extension ring 2 and the grouting system 5 are arranged, the mortar 9 synchronously injected into the shield machine is longer in solidification time, so that part of mortar 9 runs off from a gap between the mortar stop plate 1 and the duct piece 6, when the cavity behind the wall of the duct piece 6 cannot be filled, the first quick setting slurry is injected into the cavity behind the wall of the duct piece 6 through the grouting ball valve 21 on the first extension ring 2, meanwhile, the second quick setting slurry is injected into the cavity behind the wall of the duct piece 6 through the grouting system 5, the quick setting slurry is enabled to fill the cavity behind the wall of the duct piece 6 quickly, the effect of quickly plugging the cavity behind the wall of the duct piece 6 is achieved, when a station is located in a water-rich stratum, the quick setting slurry is injected into the cavity behind the wall of the duct piece 6 through the first extension ring 2 and the grouting system 5, the cavity behind the wall of the duct piece 6 is filled, water, mud and sand are prevented from flowing out through the cavity behind the wall of the duct piece 6, the tunnel gate structure is protected, and the construction safety of the shield is further protected.

In a preferred mode, as shown in fig. 2-3, grouting ball valves 21 are arranged at intervals on the upper part of a first extending ring 2, and the grouting ball valves 21 are located in grooves of the first extending ring 2, so that first quick-setting slurry is conveniently injected into a cavity on the rear upper part of the wall of a duct piece 6 through the grouting ball valves 21, further, the cavity on the rear upper part of the wall of the duct piece 6 is quickly filled, further, the number of the grouting ball valves 21 is not less than 6, grouting efficiency of the grouting ball valves 21 is improved by arranging a plurality of grouting ball valves 21, an included angle between adjacent grouting ball valves 21 is theta, wherein the included angle theta is 20 degrees, so that the first extending ring 2 of the grouting ball valves 21 is uniformly arranged at intervals, further, the included angle alpha between the farthest grouting ball valves 21 and the vertical center line of the first extending ring 2 is alpha, and the included angle alpha is 50 degrees, so that the grouting ball valves 21 are all located on the upper part of the first extending ring 2.

Wherein, first extension ring 2 includes annular bottom plate and connects the flange board in annular bottom plate both sides, both sides flange board and annular bottom plate form the recess to set up the gusset in the recess, wherein, annular bottom plate, flange board and gusset are the steel sheet, adopt the welding mode to connect, and further, first extension ring 2 is assembled by 4 sections and is formed, and annular bottom plate and flange board are assembled by 4 sections promptly, in construction operation, and annular bottom plate thickness is preferably 20mm, and flange board thickness is preferably 10mm.

In a preferred manner, as shown in fig. 1 and fig. 7-8, the grouting system 5 comprises a communicating pipe 55, a pipe piece grouting hole 61 is formed in the upper portion of the pipe piece 6, the communicating pipe 55 is installed on the upper portion of the pipe piece 6 and is communicated with the pipe piece grouting hole 61, so that the communicating pipe 55 is connected with a cavity behind the wall of the pipe piece 6 through the pipe piece grouting hole 61, the grouting system 5 injects second-speed coagulating liquid into the cavity behind the wall of the pipe piece 6 through the communicating pipe 55, so that the cavity behind the wall of the pipe piece 6 is filled, the strength of soil body 10 around the pipe piece 6 is further increased, the tunnel 110 is firmer, and the safety of the subsequent construction of a shield is guaranteed.

In a preferred manner, as shown in fig. 1 and 7, the grouting system 5 comprises a three-fork mixing device 51, a two-liquid grouting device 52 and a rubber hose 53, wherein the two-liquid grouting device 52 is communicated with the three-fork mixing device 51 through the rubber hose 53, the three-fork mixing device 51 is communicated with a communicating pipe 55, further, the three-fork mixing device 51 comprises two input pipes 511 and a mixing pipe 512, one end of each input pipe 511 is communicated with the mixing pipe 512, the other end of each input pipe 511 is communicated with the two-liquid grouting device 52 through the rubber hose 53, the mixing pipe 512 is communicated with the communicating pipe 55, two groups of slurry outlets are cement slurry outlets, one group of slurry outlets is glass water outlets, the two groups of slurry outlets are communicated with one input pipe 511 of the three-fork mixing device 51 through the rubber hose 53, the two groups of slurry outlets of the two-liquid grouting device 52 are input into the communicating pipe 55 through the mixing pipe 512 after being mixed in the three-fork mixing device 51, and then are input into the communicating pipe 61 through the wall thickness of the wall thickness 6 of the wall segment, and thus the cavity 61 is filled.

In actual construction, the quick setting slurry injected into the cavity behind the pipe piece 6 through the pipe piece grouting holes 61 by the grouting system 5 is the second quick setting slurry, and the quick setting slurry injected into the cavity behind the pipe piece 6 from the grouting ball valve 21 through other grouting equipment or the double-liquid grouting equipment 52 outside is the first quick setting slurry.

In a preferred form, as shown in fig. 7, a ball check valve 54 is mounted between the mixing tube 512 and the tube piece grouting hole 61, and by providing the ball check valve 54, the ball valve is closed to prevent the rapid hardening slurry from flowing back into the three-fork mixing device 51 when the rapid hardening slurry reaches the design pressure.

In a preferred manner, as shown in fig. 8, in order to improve the grouting efficiency of the grouting system 5, a plurality of three-fork mixing devices 51 are arranged at intervals on the top of the same segment 6.

In a preferred mode, as shown in fig. 8, the three-fork mixing device is further provided with a working platform 100, wherein the working platform 100 is used for arranging the three-fork mixing device 51, namely, in the construction process, the working platform 100 is firstly erected in the duct piece 6, during construction, an operator installs the three-fork mixing device 51 on the working platform 100, meanwhile, the rubber hose 53 is also convenient to install through the working platform 100, the rubber hose 53 is communicated with the three-fork mixing device 51 and the double-liquid grouting equipment, the working platform 100 is formed by splicing scaffolds, the working platform 100 is erected along the axial direction of the duct piece 6, the erection length of the working platform 100 in the duct piece 6 is greater than the combined length of four duct pieces 6, so that the operator can conveniently install the three-fork mixing device 51 on the working platform 100, and further, the scaffold erected on the working platform 100 is abutted against the inner wall of the duct piece 6, so that the working platform 100 plays a supporting role on the inner wall of the duct piece 6, and the protective role is played on the duct piece 6.

The rear cavity and the cavity of the duct piece wall in this embodiment refer to the cavity of the rear upper part of the duct piece wall.

Example 2

As shown in fig. 2 and fig. 4, on the basis of embodiment 1, this embodiment discloses a mortar reinforcement system, including a portal steel ring 3, a grout stop plate 1, a duct piece 6 and a mortar reinforcement device of a shield tunnel according to embodiment 1, where the grout stop plate 1 includes a fan-shaped pressing plate 11 and an annular sealing member 15, the fan-shaped pressing plate 11 is used for fixing the annular sealing member 15, the annular sealing member 15 is abutted with the duct piece 6, and a fixed annular plate 12 is further disposed between the fan-shaped pressing plate 11 and the annular sealing member 15.

The embodiment discloses mortar reinforcement system, including portal steel ring 3, end thick liquid board 1, section of jurisdiction 6 and embodiment 1 a mortar reinforcement device in shield tunnel, first extension ring 2 is connected with portal steel ring 3, end thick liquid board 1 connects in the one side that first extension ring 2 kept away from portal steel ring 3, end thick liquid board 1 includes fan-shaped clamp plate 11 and annular seal 15, fan-shaped clamp plate 11 is used for fixed annular seal 15, promptly fix annular seal 15 at first extension ring 2 through fan-shaped clamp plate 11, and annular seal 15 and section of jurisdiction 6 looks butt, thereby seal the gap between first extension ring 2 and section of jurisdiction 6 through annular seal 15, avoid the mortar 9 after the section of jurisdiction 6 wall to spill, further, as shown in fig. 4, still be provided with fixed annular plate 12 between fan-shaped clamp plate 11 and annular seal 15, increase the area of contact of fan-shaped clamp plate 11 and annular seal 15 through addding fixed annular plate 12, thereby make fan-shaped clamp plate 11 can fix annular seal 15 better, and then strengthen the sealed effect of thick liquid board 1.

According to the mortar reinforcing system, the gap between the first extension ring 2 and the duct piece 6 is sealed through the mortar stopping plate 1, mortar 9 on the wall of the duct piece 6 is prevented from overflowing, the effect of sealing the mortar 9 is achieved, the cavity with the wall thickness of the duct piece 6 is filled and compacted through the mortar reinforcing device of the shield tunnel, and the mortar 9 is reinforced through the cooperation of the tunnel portal steel ring 3, the mortar stopping plate 1, the duct piece 6 and the mortar reinforcing device, so that the tunnel portal structure is protected, and shield operation safety is further protected

As shown in fig. 4 and 6, the slurry stopping plate 1 further comprises a fan-shaped turning plate 14, the fan-shaped turning plate 14 is hinged with the fan-shaped pressing plate 11 through a pin shaft 13, so that the fan-shaped turning plate 14 can rotate around the pin shaft 13 relative to the fan-shaped pressing plate 11, in construction operation, the fan-shaped pressing plate 11 is abutted against an annular sealing piece 15 and used for supporting the annular sealing piece 15, wherein the fan-shaped pressing plate 11, the fixed annular plate 12 and the annular sealing piece 15 are fixed on the first extension ring 2 through connecting bolts 16, the first extension ring 2 is connected on the tunnel portal steel ring 3 through the fixing bolts, the tunnel portal steel ring 3 is connected with anchoring steel bars 4 embedded in the station structure 7, and connecting steel bars, connecting steel bars and the like can be embedded in the station structure 7 on the basis of the anchoring steel bars 4 for reinforcing the connection strength between the tunnel portal steel ring 3 and the station structure 7.

As shown in fig. 3-5, the grout stop plate 1 is circumferentially arranged around the first extension ring 2, and the fan-shaped turning plate 14 of the grout stop plate 1 abuts against the duct piece 6, so as to further enhance the sealing performance of the grout stop plate 1.

In a preferred manner, a bending part 151 is arranged on one side, close to the duct piece 6, of the annular sealing member 15, and the bending part 151 is abutted against the duct piece 6, so that the contact area between the annular sealing member 15 and the duct piece 6 is increased.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims (10)

1. A mortar reinforcing apparatus for a shield tunnel, comprising:

the grouting device comprises a first extension ring (2) and a grouting pipe, wherein the first extension ring (2) is used for being connected between a portal steel ring (3) and a grouting stop plate (1), a grouting ball valve (21) is arranged on the first extension ring (2), and the grouting ball valve (21) is used for injecting first quick-setting slurry into a cavity behind the wall of a pipe piece (6);

and the grouting system (5) can penetrate through the duct piece (6) and inject second-speed coagulating slurry into the cavity behind the duct piece (6).

2. Mortar reinforcing device for a shield tunnel according to claim 1, characterized in that the grouting ball valves (21) are arranged at intervals on the upper part of the first extension ring (2).

3. The mortar reinforcing device for a shield tunnel according to claim 2, wherein the number of the grouting ball valves (21) is not less than 6, and an included angle between adjacent grouting ball valves (21) is θ, wherein the included angle θ is 20 °.

4. A mortar reinforcement device for a shield tunnel according to claim 3, characterized in that the angle between the most distant grouting ball valve (21) and the vertical centre line of the first extension ring (2) is α, wherein the angle α is 50 °.

5. The mortar reinforcing device of the shield tunnel according to claim 1, wherein the grouting system (5) comprises a communicating pipe (55), the communicating pipe (55) is arranged on the duct piece (6), and the communicating pipe (55) is communicated with a cavity behind the wall of the duct piece (6).

6. The mortar reinforcing device for a shield tunnel according to claim 5, wherein the grouting system (5) further comprises a three-fork mixing device (51) and a two-liquid grouting device (52), the three-fork mixing device (51) comprises two input pipes (511) and one mixing pipe (512), each input pipe (511) is communicated with the mixing pipe (512), the two-liquid grouting device (52) comprises two groups of slurry output ports, each group of slurry output ports is communicated with one input pipe (511), and the mixing pipe (512) is communicated with the communicating pipe (55).

7. A mortar reinforcement device for a shield tunnel according to claim 1, further comprising a work platform (100), said work platform (100) being adapted to mount said grouting system (5).

8. The mortar reinforcing device for a shield tunnel according to claim 7, wherein the working platform (100) is erected along the axial direction of the segment (6).

9. Mortar reinforcing system, characterized in that, including portal steel ring (3), end thick liquid board (1), section of jurisdiction (6) and a shield tunnel's mortar reinforcing apparatus of any one of claims 1-8, end thick liquid board (1) including fan-shaped clamp plate (11) and annular seal (15), fan-shaped clamp plate (11) are used for fixing annular seal (15), annular seal (15) with section of jurisdiction (6) looks butt, fan-shaped clamp plate (11) with still be provided with fixed annular plate (12) between annular seal (15).

10. Mortar reinforcing system according to claim 9, wherein the annular sealing member (15) is provided with a bending portion (151) at a side close to the segment (6), the bending portion (151) being in abutment with the segment (6).