Tunnel portal structure

Abstract

The invention discloses a tunnel portal structure, and relates to the technical field of tunnel shield method construction. The tunnel portal structure comprises a portal body. The tunnel portal arch ring is arranged on the outer wall of the tunnel portal main body and sequentially comprises a first area, a second area and a third area from inside to outside; the cord fabric rubber plate is laid on the first area in a surrounding manner through the first pre-embedded steel ring of the first area; the steel wire brush is arranged on the inner wall of the tunnel portal body in a surrounding mode and used for forming a grouting space with a pipe piece of the shield tunneling machine, the curtain cloth rubber plate and the inner wall of the tunnel portal body; and the grouting channel is used for grouting the grouting space. Grouting is carried out in the grouting space formed by the steel wire brush, the pipe piece, the cord fabric rubber plate and the inner wall of the tunnel portal body, a sealing layer is formed, the interior and the exterior of a tunnel are isolated, water cannot flow out in the drilling process, grouting cannot make contact with the steel sleeve, and therefore when a shield tunneling machine assisted by the steel sleeve is started, the construction efficiency is improved. And the sealing safety of the tunnel portal is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel shield construction, and in particular to a tunnel portal structure. Background Art

[0002] The shield method is widely used in tunnel construction projects because of its fast construction speed and small disturbance to the ground. The shield starting working shaft reserves a starting hole. In order to prevent water and soil from flowing into the shaft and causing construction difficulties, the reserved hole is blocked. The conventional shield machine starts by installing a rubber sheet on the outside of the steel ring of the tunnel portal, and tightening the wire rope after the shield tail is separated from the tunnel portal to make the rubber sheet fit closely with the outer arc surface of the segment, and then grouting the gap behind the segment wall to effectively block the tunnel portal.

[0003] At present, when a shield machine assisted by a steel sleeve is started, firstly, when the gap between the segments at the tunnel portal and the surrounding soil is grouting and filled for reinforcement, the slurry easily flows into the steel sleeve and solidifies, causing the steel sleeve to adhere to the negative ring segments or the shield machine body, making the subsequent removal of the steel sleeve extremely difficult; secondly, during the cutting process of the steel sleeve connection section, the portal is prone to leakage; finally, the steel sleeve needs to be set on the embedded steel ring of the portal arch through a transition ring, but the curtain rubber sheet also needs to be installed here, so there is a conflict in the installation positions of the two, resulting in the problem of tunnel portal sealing safety during the start of the shield machine. Summary of the invention

[0004] In view of the defects existing in the prior art, the technical problem solved by the present invention is: how to improve the sealing safety of the tunnel portal when a shield machine assisted by a steel sleeve is started.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a tunnel portal structure, comprising: The main body of the cave entrance; The gate arch ring is arranged on the outer wall of the gate body and includes a first area, a second area and a third area from the inside to the outside; The rubber sheet of the cord is laid on the first area by surrounding the first embedded steel ring of the first area; A wire brush is disposed around the inner wall of the tunnel portal body and is used to form a grouting space with the shield machine segments, the curtain rubber sheet and the inner wall of the tunnel portal body; A grouting channel comprises a grouting inlet, a grouting pipe and a grouting outlet. The grouting inlet and the grouting outlet are respectively arranged at both ends of the grouting pipe. The grouting inlet is opened in the third area. The grouting outlet is penetrated inside the grouting space. A first pressure sensor is arranged on the inner wall of the portal body on one side of the grouting outlet.

[0006] By adopting the above technical solution, the shield machine is placed inside the tunnel portal and is pressed against the rubber curtain sheet and the wire brush, so that the rubber curtain sheet and the wire brush are deformed in the direction in which the shield machine is to move, and because both have resilience, they are both fitted with the outer wall of the shield machine, and pipe segments are laid on the outer wall of the shield machine between the rubber curtain sheet and the wire brush. At this time, the rubber curtain sheet and the wire brush are fitted and pressed against the pipe segments, and a grouting space is formed around the wire brush, the pipe segments, the rubber curtain sheet and the inner wall of the portal body, and mortar is poured into the grouting space through the grouting channel until the first pressure sensor reaches a threshold value, and the mortar in the grouting space is formed. Sealing layer, so when the shield machine is started, the water generated by drilling will be isolated by the sealing layer, thereby solving the problem of portal leakage that is very easy to occur during the cutting of the steel sleeve connecting section, and solving the problem that when the gap between the pipe segment at the tunnel portal and the surrounding soil is grouting and filled for reinforcement at the start of the shield, the slurry is easy to flow into the steel sleeve and consolidate, causing the steel sleeve to adhere to the negative ring pipe segment or the shield machine body, making the subsequent removal of the steel sleeve extremely difficult. The reason is that the mortar filled by grouting will also be isolated by the sealing layer and will not contact the steel sleeve, thereby improving the sealing safety of the tunnel portal when the shield machine assisted by the steel sleeve is started.

[0007] In combination with the first aspect, in one embodiment, the wire brush includes a mounting portion, a first rebound component and a sealing portion, the mounting portion is fixedly connected to the inner wall of the tunnel portal body, one end of the sealing portion is rotatably connected to the mounting portion through the first rebound component, and the other end of the sealing portion is used to abut against the pipe segment.

[0008] By adopting the above technical solution, one end of the sealing part rotates around the mounting part with the first rebound component as the origin. When the sealing part abuts against the pipe segment, the first rebound component generates a force to restore the sealing part, thereby making the sealing part abut against the pipe segment more tightly, thereby enhancing the sealing between the sealing part and the pipe segment.

[0009] In one embodiment, the mounting portion includes an exposed fixing part, a mounting body and an embedded fixing part, the embedded fixing part is arranged inside an embedded groove on the inner wall of the tunnel door body, one end of the exposed fixing part is fixedly connected to one end of the embedded fixing part, the exposed fixing part is sleeved on the mounting body, one side of the mounting body is against the inner wall of the tunnel door body, and the other side thereof is against the inner wall of the exposed fixing part, a plurality of rivets are commonly penetrated on the exposed fixing part, the mounting body, the embedded fixing part and the inner wall of the tunnel door body, one end of the mounting body is fixedly connected to the inner wall of the exposed fixing part by a bolt assembly, and the other end thereof is rotatably connected to the sealing part by a first rebound assembly.

[0010] By adopting the above technical scheme, the embedded fixing part for fixing the installation body is arranged inside the embedded groove of the inner wall of the tunnel body, and the exposed fixing part and the embedded fixing part are spliced ​​inside the embedded groove, which not only improves the stability of the installation of the installation part, but also improves the sealing of the installation part, avoids the mortar inside the grouting space from flowing out from the installation position of the installation part, and avoids the water from flowing into the installation position of the installation part during drilling; one end of the installation body is fixedly connected to the inner wall of the exposed fixing part by a bolt assembly, which improves the stability of the connection between the installation body and the exposed fixing part; a plurality of rivets are commonly penetrated on the exposed fixing part, the installation body, the embedded fixing part and the inner wall of the tunnel body, which improves the stability of the installation of the installation part.

[0011] In one embodiment, a second pressure sensor is disposed on the outer wall of the exposed fixing member.

[0012] By adopting the above technical solution, when pouring mortar, the first area to be filled up is the first pressure sensor, and then spreads to the sides. Therefore, it is not accurate enough to judge whether the mortar is poured up to standard only by the value of the first pressure sensor. Therefore, a second pressure sensor is provided on the outer wall of the exposed fixing part, which can not only judge whether there is mortar at the position of the wire brush, but also judge whether the mortar pouring at the position of the wire brush is up to standard by comparing the value of the second pressure sensor with the value of the first pressure sensor.

[0013] In one embodiment, the sealing part includes a first guard plate, a second guard plate and a sealing steel wire. The mounting body can be rotatably mounted on one end of the mounting body through a first rebound assembly. The first guard plate and the second guard plate are respectively mounted on two sides of the sealing steel wire. One end of the first guard plate can be rotatably set on an exposed fixing member, and one end of the second guard plate can be rotatably set on the inner wall of the portal body.

[0014] By adopting the above technical scheme, the first guard plate and the second guard plate not only protect the sealing steel wire, but also one end of the first guard plate can rotate around the exposed fixing part, and one end of the second guard plate can rotate around the inner wall of the tunnel door body. Therefore, when the sealing steel wire is deformed, the first guard plate and the second guard plate are deformed along with the sealing steel wire, and deform together in the direction of the second guard plate. Therefore, when the deformation reaches a certain extent, the first guard plate can be against the pipe segment, thereby further improving the sealing between the sealing part and the pipe segment.

[0015] In one embodiment, a second embedded steel ring is arranged around the second area, and a steel sleeve is arranged in the second area through the second embedded steel ring.

[0016] By adopting the above technical solution, the steel sleeve is not provided with a transition ring, but is directly fixed by the second embedded steel ring, and the problem of conflict between the installation position of the steel sleeve and the cord rubber plate is avoided.

[0017] In one embodiment, the steel sleeve includes a steel layer, a Bailey frame layer and a guide layer. The steel layer is fixedly connected to the second area through a second embedded steel ring. The Bailey frame layer is arranged on the inner wall of the steel layer. One end of the Bailey frame layer is abutted against the cord rubber plate located in the first area. The guide layer is arranged on the inner wall of the Bailey frame layer. The guide layer is used to guide the drilling direction of the shield machine.

[0018] By adopting the above technical scheme, since the steel layer of the steel sleeve not only has no transition ring, but also is misaligned with the installation position of the cord rubber plate, it is necessary to solve the problem that there is no transition ring, resulting in a structure without enhanced structural stability and the sealing effect of the transition ring. Therefore, a Bailey frame layer is arranged around the inner wall of the steel layer, and a guide layer is arranged around the inner wall of the Bailey frame layer. The effects of the Bailey frame layer are: first, the structural stability of the entire steel sleeve is enhanced; second, because the Bailey frame layer is offset against the cord rubber plate located in the first area, the sealing between the steel sleeve and the cord rubber plate is improved; third, because the steel layer is located in the second area, the inner wall diameter of the steel layer is larger than the diameter of the hole, and the shield machine cannot enter the hole through the steel layer. Therefore, the Bailey frame layer also reduces the diameter of the inside of the steel sleeve, and the shield machine can enter the hole along the guide layer laid on the Bailey frame.

[0019] In one embodiment, the cord rubber sheet includes a first rubber segment and a second rubber segment, one side of the first rubber segment is fixed to the first area through a first embedded steel ring, and the other side thereof is abutted against the Bailey frame layer, one end of the second rubber segment is fixedly connected to the first rubber segment, and the other end thereof is used to abut against the tube segment.

[0020] By adopting the above technical solution, the first rubber section is used to resist the Bailey frame layer and is fixed to the portal arch ring through the first embedded steel ring. Since the cord rubber sheet itself has resilience, the second rubber section is used to seal between the pipe segments.

[0021] In one embodiment, a fixing plate is provided between the first rubber segment and the Bailey frame layer, and the fixing plate is rotatably provided with a flap through a second rebound assembly, and one side of the flap is fixedly connected to the second rubber segment.

[0022] By adopting the above technical solution, on the basis that the cord rubber sheet itself has resilience, a fixing plate is added to the first rubber segment, a flap is added to the second rubber segment, and a second rebound component is arranged between the fixing plate and the flap. Therefore, when the second rubber segment is deformed, not only the resilience of the cord rubber sheet itself generates a restoring force, but the second rebound component also generates a restoring force, thereby further enhancing the sealing performance between the second rubber segment and the pipe segment.

[0023] In a second aspect, the invention provides a shield machine-starting construction method, comprising the following steps: Provide tunnel portal structure; The shield machine is installed on the guide layer of the steel sleeve. The shield machine moves along the guide layer into the tunnel portal. The outer wall of the shield machine drives the rubber sheet and the wire brush to deform. The pipe segments are laid on the outer wall of the shield machine between the curtain rubber sheet and the wire brush, and the wire brush, the pipe segments, the curtain rubber sheet and the inner wall of the tunnel body are surrounded to form a grouting space; The grouting space is filled with mortar through the grouting channel until the values ​​of the first pressure sensor and the second pressure sensor are the same; After the mortar solidifies, the mortar in the grouting space forms a sealing layer and the shield machine starts.

[0024] By adopting the above technical solution, the shield machine is placed inside the tunnel portal and is pressed against the rubber curtain sheet and the wire brush, so that the rubber curtain sheet and the wire brush are deformed in the direction in which the shield machine is to move, and because both have resilience, they are both fitted with the outer wall of the shield machine, and pipe segments are laid on the outer wall of the shield machine between the rubber curtain sheet and the wire brush. At this time, the rubber curtain sheet and the wire brush are fitted and pressed against the pipe segments, and a grouting space is formed around the wire brush, the pipe segments, the rubber curtain sheet and the inner wall of the portal body, and mortar is poured into the grouting space through the grouting channel until the first pressure sensor reaches a threshold value, and the mortar in the grouting space is formed. Sealing layer, so when the shield machine is started, the water generated by drilling will be isolated by the sealing layer, thereby solving the problem of portal leakage that is very easy to occur during the cutting of the steel sleeve connecting section, and solving the problem that when the gap between the pipe segment at the tunnel portal and the surrounding soil is grouting and filled for reinforcement at the start of the shield, the slurry is easy to flow into the steel sleeve and consolidate, causing the steel sleeve to adhere to the negative ring pipe segment or the shield machine body, making the subsequent removal of the steel sleeve extremely difficult. The reason is that the mortar filled by grouting will also be isolated by the sealing layer and will not contact the steel sleeve, thereby improving the sealing safety of the tunnel portal when the shield machine assisted by the steel sleeve is started.

[0025] In summary, the present invention includes at least one of the following beneficial technical effects: 1. Grouting is performed inside the grouting space formed by the wire brush, pipe segment, rubber sheet and the inner wall of the tunnel portal to form a sealing layer to isolate the inside and outside of the tunnel. Water will not flow out during the drilling process, and the grouting will not contact the steel sleeve, thereby improving the sealing safety of the tunnel portal when the shield machine assisted by the steel sleeve is started; 2. The design structure of the steel sleeve does not require a transition ring to fix it to the arch ring of the tunnel, thus avoiding the problem of conflict with the installation position of the cord rubber sheet, and there will be no problems with sealing and structural stability caused by the absence of a transition ring; 3. The structural design of the curtain rubber sheet and wire brush can improve the sealing of the grouting space and further enhance the waterproof leakage effect of the sealing layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a tunnel portal structure according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a shield machine installed on a tunnel portal structure according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of a wire brush according to an embodiment of the present invention; Figure 4 Schematic diagram of the structure of the rubber sheet of the cord according to the embodiment of the present invention.

[0027] In the figure: 1-portal body, 101-portal arch ring, 102-embedded groove, 2-cord rubber plate, 201-first rubber segment, 202-second rubber segment, 203-fixing plate, 204-second rebound component, 205-flap, 3-wire brush, 301-installation body, 302-first rebound component, 303-sealing steel wire, 304-embedded fixing part, 305-exposed fixing part, 306-bolt assembly, 307-rivet, 308-first guard plate, 309-second guard plate, 4-steel sleeve, 5-grouting inlet, 6-grouting pipe, 7-grouting outlet, 8-first pressure sensor, 9-shield machine, 10-segment, 11-second pressure sensor. DETAILED DESCRIPTION

[0028] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0029] The tunnel portal structure in the embodiment of the present invention is shown in FIG. Figure 1 , 2 As shown, the tunnel portal structure includes a portal body 1; a portal arch ring 101 is arranged on the outer wall of the portal body 1, and the portal arch ring 101 includes a first area, a second area and a third area from the inside to the outside, and the three areas are all arranged in a surrounding manner, but they are not necessarily circular rings; the cord rubber sheet 2 is laid on the first area through a first embedded steel ring in the first area; the wire brush 3 is arranged on the inner wall of the portal body 1 in a surrounding manner, and the wire brush 3 is used to form a grouting space with the pipe segment 10 of the shield machine 9, the cord rubber sheet 2 and the inner wall of the portal body 1; the grouting channel includes a grouting inlet 5, a grouting pipe 6 and a grouting outlet 7, and the grouting inlet 5 and the grouting outlet 7 are respectively arranged at both ends of the grouting pipe 6, the grouting inlet 5 is opened in the third area, and the grouting outlet 7 is arranged inside the grouting space, and a first pressure sensor 8 is arranged on the inner wall of the portal body 1 on one side of the grouting outlet 7.

[0030] It can be seen that the present invention puts the shield machine 9 into the interior of the tunnel portal, and abuts against the curtain rubber sheet 2 and the wire brush 3, so that the curtain rubber sheet 2 and the wire brush 3 are deformed in the direction in which the shield machine 9 is to move, and because both have resilience, they are both fitted with the outer wall of the shield machine 9, and the pipe segment 10 is laid on the outer wall of the shield machine 9 between the curtain rubber sheet 2 and the wire brush 3. At this time, the curtain rubber sheet 2 and the wire brush 3 are fitted and abutted against the pipe segment 10, and the wire brush 3, the pipe segment 10, the curtain rubber sheet 2 and the inner wall of the tunnel portal body 1 are surrounded to form a grouting space, and mortar is poured into the grouting space through the grouting channel until the first pressure sensor 8 reaches the threshold value, and the sand in the grouting space The slurry forms a sealing layer, so when the shield machine 9 is started, the water generated by drilling will be isolated by the sealing layer, thereby solving the problem of portal leakage that is very likely to occur during the cutting of the connecting section of the steel sleeve 4, and solving the problem that when the gap between the pipe segment 10 and the surrounding soil at the tunnel portal is grouting and filled for reinforcement at the start of the shield, the slurry is easy to flow into the steel sleeve 4 and consolidate, causing the steel sleeve 4 to adhere to the negative ring pipe segment 10 or the shield machine 9 body, making the subsequent removal of the steel sleeve 4 extremely difficult. The reason is that the mortar filled by grouting will also be isolated by the sealing layer and will not contact the steel sleeve 4, thereby improving the sealing safety of the tunnel portal when the shield machine 9 assisted by the steel sleeve 4 is started.

[0031] Preferably, a specific structure of a wire brush 3 is provided: The wire brush 3 includes a mounting portion, a first rebound component 302 and a sealing portion. The mounting portion is fixedly connected to the inner wall of the tunnel portal body 1. One end of the sealing portion is rotatably connected to the mounting portion through the first rebound component 302, and the other end of the sealing portion is used to abut against the pipe segment 10.

[0032] Specifically, one end of the sealing part rotates around the mounting part with the first rebound component 302 as the origin. When the sealing part abuts against the pipe segment 10, the first rebound component 302 generates a force to restore the sealing part, thereby making the sealing part abut against the pipe segment 10 more tightly, thereby strengthening the sealing between the sealing part and the pipe segment 10.

[0033] For further information, see Figure 3 As shown, a specific structure of a mounting portion is provided: The mounting portion includes an exposed fixing piece 305, a mounting body 301 and an embedded fixing piece 304. The embedded fixing piece 304 is arranged inside the embedded groove 102 on the inner wall of the tunnel door body 1. One end of the exposed fixing piece 305 is fixedly connected to one end of the embedded fixing piece 304. The exposed fixing piece 305 is sleeved on the mounting body 301. One side of the mounting body 301 abuts against the inner wall of the tunnel door body 1, and the other side thereof abuts against the inner wall of the exposed fixing piece 305. A plurality of rivets 307 are commonly penetrated on the exposed fixing piece 305, the mounting body 301, the embedded fixing piece 304 and the inner wall of the tunnel door body 1. One end of the mounting body 301 is fixedly connected to the inner wall of the exposed fixing piece 305 by a bolt assembly 306, and the other end thereof is rotatably connected to the sealing portion by a first rebound assembly 302.

[0034] Specifically, the embedded fixing piece 304 for fixing the installation body 301 is arranged inside the embedded groove 102 of the inner wall of the tunnel portal body 1, and the exposed fixing piece 305 is spliced ​​with the embedded fixing piece 304 inside the embedded groove 102, and part of the exposed fixing piece 305 is located inside the embedded groove 102, and the installation body 301 is clamped between the exposed fixing piece 305 and the inner wall of the tunnel portal body 1, which not only improves the stability of the installation of the installation part, but also improves the sealing of the installation part, avoids the mortar inside the grouting space from the installation part of the installation part to flow out, and also avoids the water from the installation part of the installation part to flow into the grouting space during drilling; one end of the installation body 301 is fixedly connected to the inner wall of the exposed fixing piece 305 by the bolt assembly 306, which improves the stability of the connection between the installation body 301 and the exposed fixing piece 305; a plurality of rivets 307 are commonly penetrated on the exposed fixing piece 305, the installation body 301, the embedded fixing piece 304 and the inner wall of the tunnel portal body 1, which improves the stability of the installation of the installation part.

[0035] For further information, see Figure 1 As shown, a second pressure sensor 11 is disposed on the outer wall of the exposed fixing member 305 .

[0036] Specifically, when pouring mortar, the first area to be filled up is the first pressure sensor 8, and then spreads to the sides. Therefore, it is not accurate enough to judge whether the mortar is poured up to standard only by the value of the first pressure sensor 8. Therefore, a second pressure sensor 11 is provided on the outer wall of the exposed fixing part 305, which can not only judge whether there is mortar at the location of the wire brush 3, but also judge whether the mortar pouring at the location of the wire brush 3 is up to standard by comparing the value of the second pressure sensor 11 with the value of the first pressure sensor 8.

[0037] Preferably, see Figure 3 As shown, a specific structure of a sealing portion is provided: The sealing part includes a first guard plate 308, a second guard plate 309 and a sealing steel wire 303. The mounting body 301 can be rotatably mounted on one end of the mounting body 301 through a first rebound assembly 302. The first guard plate 308 and the second guard plate 309 are respectively mounted on two sides of the sealing steel wire 303. One end of the first guard plate 308 can be rotatably set on the exposed fixing part 305, and one end of the second guard plate 309 can be rotatably set on the inner wall of the portal body 1.

[0038] Specifically, the sealing steel wire 303 is installed on one end of the installation body 301 through the first rebound component 302, that is, one end of the sealing steel wire 303 rotates around one end of the installation body 301 with the first rebound component 302 as the origin, the first guard plate 308 is attached to the side of the sealing steel wire 303 located inside the grouting space, and the second guard plate 309 is attached to the side of the sealing steel wire 303 located outside the grouting room. The first guard plate 308 and the second guard plate 309 are not only for protecting the sealing steel wire 303, Moreover, one end of the first guard plate 308 can rotate around the exposed fixing piece 305, and one end of the second guard plate 309 can rotate around the inner wall of the portal body 1. Therefore, when the sealing steel wire 303 is deformed, the first guard plate 308 and the second guard plate 309 are deformed along with the sealing steel wire 303, and they are deformed together in the direction of the second guard plate 309. Therefore, when the deformation reaches a certain extent, the first guard plate 308 can be against the pipe segment 10, thereby further improving the sealing between the sealing part and the pipe segment 10.

[0039] Preferably, a second embedded steel ring is arranged around the second area, and a steel sleeve 4 is arranged in the second area through the second embedded steel ring.

[0040] Specifically, the steel sleeve 4 is directly fixed by the second embedded steel ring, eliminating the transition ring in the prior art, thereby avoiding the problem of conflict between the installation positions of the steel sleeve 4 and the cord rubber plate 2 .

[0041] For further information, see Figure 1 , 2 As shown, a specific structure of a steel sleeve 4 is provided: The steel sleeve 4 includes a steel layer, a Bailey frame layer and a guide layer. The steel layer is fixedly connected to the second area through a second embedded steel ring. The Bailey frame layer is arranged on the inner wall of the steel layer. One end of the Bailey frame layer is abutted against the cord rubber plate 2 located in the first area. The guide layer is arranged on the inner wall of the Bailey frame layer. The guide layer is used to guide the drilling direction of the shield machine 9.

[0042] Specifically, since the steel layer of the steel sleeve 4 not only has no transition ring, but also is misaligned with the installation position of the cord rubber sheet 2, it is necessary to solve the problem that there is no transition ring, resulting in a structure without enhanced structural stability and the sealing effect of the transition ring. Therefore, a Bailey frame layer is arranged around the inner wall of the steel layer, and a guide layer is arranged around the inner wall of the Bailey frame layer. The effects of the Bailey frame layer are: first, the structural stability of the entire steel sleeve 4 is enhanced; second, because the Bailey frame layer is against the cord rubber sheet 2 located in the first area, the sealing between the steel sleeve 4 and the cord rubber sheet 2 is improved; third, because the steel layer is located in the second area, the inner wall diameter of the steel layer is larger than the diameter of the cave entrance, and the shield machine 9 cannot enter the cave through the steel layer. Therefore, the Bailey frame layer also reduces the diameter inside the steel sleeve 4, and the shield machine 9 can enter the cave along the guide layer laid on the Bailey frame.

[0043] For further information, see Figure 1 , 4 As shown, a specific structure of a cord rubber sheet 2 is provided: The cord rubber sheet 2 includes a first rubber segment 201 and a second rubber segment 202. One side of the first rubber segment 201 is fixed to the first area through a first embedded steel ring, and the other side thereof abuts against the Bailey frame layer. One end of the second rubber segment 202 is fixedly connected to the first rubber segment 201, and the other end thereof is used to abut against the pipe segment 10.

[0044] Specifically, the first rubber section 201 is used to abut against the Bailey frame layer and is fixed to the portal arch ring 101 through a first embedded steel ring. Since the cord rubber sheet 2 itself has resilience, the second rubber section 202 is used to seal between the pipe segment 10 .

[0045] For further information, see Figure 4 As shown, a fixing plate 203 is provided between the first rubber segment 201 and the Bailey frame layer. The fixing plate 203 is rotatably provided with a flap 205 through a second rebound component 204 , and one side of the flap 205 is fixedly connected to the second rubber segment 202 .

[0046] Specifically, on the basis that the cord rubber sheet 2 itself has resilience, a fixing plate 203 is added to the first rubber segment 201, a flap 205 is added to the second rubber segment 202, and a second resilience component 204 is provided between the fixing plate 203 and the flap 205. Therefore, when the second rubber segment 202 is deformed, not only the resilience of the cord rubber sheet 2 itself generates a restoring force, but the second resilience component 204 also generates a restoring force, thereby further enhancing the sealing performance between the second rubber segment 202 and the pipe segment 10.

[0047] The construction method initiated by the shield machine 9 in the embodiment of the present invention comprises the following steps: Provide tunnel portal structure; The shield machine 9 is installed on the guide layer of the steel sleeve 4. The shield machine 9 moves along the guide layer to the inside of the tunnel portal. The outer wall of the shield machine 9 drives the rubber sheet 2 and the wire brush 3 to deform. The pipe segment 10 is laid on the outer wall of the shield machine 9 between the curtain rubber sheet 2 and the wire brush 3, and the wire brush 3, the pipe segment 10, the curtain rubber sheet 2 and the inner wall of the tunnel body 1 form a grouting space; The grouting space is filled with mortar through the grouting channel until the values ​​of the first pressure sensor 8 and the second pressure sensor 11 are the same; After the mortar solidifies, the mortar in the grouting space forms a sealing layer, and the shield machine 9 starts.

[0048] It can be seen that the present invention puts the shield machine 9 into the interior of the tunnel portal, and abuts against the curtain rubber sheet 2 and the wire brush 3, so that the curtain rubber sheet 2 and the wire brush 3 are deformed in the direction in which the shield machine 9 is to move, and because both have resilience, they are both fitted with the outer wall of the shield machine 9, and the pipe segment 10 is laid on the outer wall of the shield machine 9 between the curtain rubber sheet 2 and the wire brush 3. At this time, the curtain rubber sheet 2 and the wire brush 3 are fitted and abutted against the pipe segment 10, and the wire brush 3, the pipe segment 10, the curtain rubber sheet 2 and the inner wall of the tunnel portal body 1 are surrounded to form a grouting space, and mortar is poured into the grouting space through the grouting channel until the first pressure sensor 8 reaches the threshold value, and the sand in the grouting space The slurry forms a sealing layer, so when the shield machine 9 is started, the water generated by drilling will be isolated by the sealing layer, thereby solving the problem of portal leakage that is very likely to occur during the cutting of the connecting section of the steel sleeve 4, and solving the problem that when the gap between the pipe segment 10 and the surrounding soil at the tunnel portal is grouting and filled for reinforcement at the start of the shield, the slurry is easy to flow into the steel sleeve 4 and consolidate, causing the steel sleeve 4 to adhere to the negative ring pipe segment 10 or the shield machine 9 body, making the subsequent removal of the steel sleeve 4 extremely difficult. The reason is that the mortar filled by grouting will also be isolated by the sealing layer and will not contact the steel sleeve 4, thereby improving the sealing safety of the tunnel portal when the shield machine 9 assisted by the steel sleeve 4 is started.

[0049] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A tunnel portal structure, comprising a portal body (1), characterized in that: It includes: A tunnel gate arch ring (101) is arranged on the outer wall of the tunnel gate body (1), and comprises, from the inside to the outside, a first area, a second area and a third area; A cord rubber sheet (2) is laid on the first area by surrounding a first pre-buried steel ring in the first area; A wire brush (3) is disposed around the inner wall of the tunnel portal body (1) and is used to form a grouting space with the segments (10) of the shield machine (9), the rubber sheet (2) and the inner wall of the tunnel portal body (1); A grouting channel comprises a grouting inlet (5), a grouting pipe (6) and a grouting outlet (7); the grouting inlet (5) and the grouting outlet (7) are respectively arranged at two ends of the grouting pipe (6); the grouting inlet (5) is opened in the third area; the grouting outlet (7) is arranged inside the grouting space; and a first pressure sensor (8) is arranged on the inner wall of the portal body (1) on one side of the grouting outlet (7).

2. The tunnel portal structure according to claim 1, characterized in that: The wire brush (3) comprises a mounting portion, a first rebound component (302) and a sealing portion, wherein the mounting portion is fixedly connected to the inner wall of the portal body (1), one end of the sealing portion is rotatably connected to the mounting portion via the first rebound component (302), and the other end of the sealing portion is used to abut against the pipe segment (10).

3. The tunnel portal structure according to claim 2, characterized in that: The mounting portion comprises an exposed fixing piece (305), a mounting body (301) and an embedded fixing piece (304); the embedded fixing piece (304) is arranged inside an embedded groove (102) on the inner wall of the tunnel door body (1); one end of the exposed fixing piece (305) is fixedly connected to one end of the embedded fixing piece (304); the exposed fixing piece (305) is sleeved on the mounting body (301); one side of the mounting body (301) is in contact with the inner wall of the tunnel door body (1); The exposed fixing member (305), the installation body (301), the embedded fixing member (304) and the inner wall of the door body (1) are all provided with a plurality of rivets (307). One end of the installation body (301) is fixedly connected to the inner wall of the exposed fixing member (305) via a bolt assembly (306), and the other end of the installation body (301) is rotatably connected to the sealing portion via a first rebound assembly (302).

4. The tunnel portal structure according to claim 3, characterized in that: A second pressure sensor (11) is provided on the outer wall of the exposed fixing member (305).

5. The tunnel portal structure according to claim 3, characterized in that: The sealing portion comprises a first guard plate (308), a second guard plate (309) and a sealing steel wire (303); the mounting body (301) is rotatably mounted on one end of the mounting body (301) via a first rebound assembly (302); the first guard plate (308) and the second guard plate (309) are respectively mounted on two sides of the sealing steel wire (303); one end of the first guard plate (308) is rotatably mounted on an exposed fixing member (305); and one end of the second guard plate (309) is rotatably mounted on an inner wall of the portal body (1).

6. The tunnel portal structure according to claim 1, characterized in that: A second embedded steel ring is arranged around the second area, and a steel sleeve (4) is arranged in the second area via the second embedded steel ring.

7. The tunnel portal structure according to claim 6, characterized in that: The steel sleeve (4) comprises a steel layer, a Bailey frame layer and a guide layer. The steel layer is fixedly connected to the second area via a second embedded steel ring. The Bailey frame layer is disposed around the inner wall of the steel layer. One end of the Bailey frame layer abuts against the cord rubber sheet (2) located in the first area. The guide layer is disposed around the inner wall of the Bailey frame layer. The guide layer is used to guide the drilling direction of the shield machine (9).

8. The tunnel portal structure according to claim 7, characterized in that: The cord rubber sheet (2) comprises a first rubber segment (201) and a second rubber segment (202); one side of the first rubber segment (201) is fixed to the first region via a first embedded steel ring, and the other side thereof abuts against the Bailey frame layer; one end of the second rubber segment (202) is fixedly connected to the first rubber segment (201), and the other end thereof is used to abut against the pipe segment (10).

9. The tunnel portal structure according to claim 8, characterized in that: A fixing plate (203) is provided between the first rubber segment (201) and the Bailey frame layer, and the fixing plate (203) is rotatably provided with a flap (205) via a second rebound component (204), and one side of the flap (205) is fixedly connected to the second rubber segment (202).

10. A construction method starting from a shield machine (9), characterized in that: It includes the following steps: Providing a tunnel portal structure as described in any one of claims 1 to 9; The shield machine (9) is installed on the guide layer of the steel sleeve (4), and the shield machine (9) moves along the guide layer into the interior of the tunnel portal, and the outer wall of the shield machine (9) drives the curtain rubber plate (2) and the wire brush (3) to deform; A pipe segment (10) is laid on the outer wall of the shield machine (9) between the curtain rubber plate (2) and the wire brush (3), and a grouting space is formed around the wire brush (3), the pipe segment (10), the curtain rubber plate (2) and the inner wall of the tunnel portal body (1); Filling the grouting space with mortar through the grouting channel until the values ​​of the first pressure sensor (8) and the second pressure sensor (11) are the same; After the mortar solidifies, the mortar in the grouting space forms a sealing layer, and the shield machine (9) starts.

Images