Shield tunnel construction method using shield safe receiving channel in karst

Abstract

The invention discloses a shield tunnel construction method using a shield safe receiving channel in karst karst, comprising a bamboo-shaped receiving channel and an end wall located on the side wall of a shield receiving working shaft, corresponding to the shield tunnel; the end wall comprises an upper half end wall arranged in a semi-circular part of the bamboo-shaped receiving channel cross section, and a lower half end wall arranged between a semi-circular part and a fully circular part of the bamboo-shaped receiving channel cross section; a plurality of system anchor rods are arranged on the outer side wall of the bamboo-shaped receiving channel located above the horizontal plane where the axis is located, a plurality of locking foot anchor rods are arranged in a part of the semi-circular part close to the horizontal plane where the axis is located, and a grouting pipe is arranged between the inner side and the outer wall of the shield tunnel; a pipe shed is arranged on the outward side of the upper half end wall. During construction, the shield receiving working shaft and the bamboo-shaped receiving channel are constructed first, and after the shield tunnel is completed, grouting and filling are performed through the grouting pipe. The invention solves the contradiction between the shield receiving and the difficulty of karst exploration and treatment in karst karst areas.

Description

Technical Field

[0001] The invention relates to the technical field of shield construction, and in particular to a shield tunnel construction method using a shield safety receiving channel in karst karst. Background Art

[0002] The shield method is an advanced method with a high degree of mechanization, fast construction progress and mature technology. It is increasingly widely used in the karst strata in the southwest, such as subway tunnels, underground passages, pipeline corridors and many other projects. The application of the shield method in karst karst inevitably faces the risks brought by the cave, especially when the shield enters and exits the cave, the presence of karst will affect the stability of the cave entrance, which directly determines the safety of entering and exiting the cave. How to take effective measures to solve the adverse effects of karst on entering and exiting the cave is the basis for the application of shield in karst karst strata.

[0003] Current status of related technologies in this field:

[0004] Before the shield machine is received, the retaining structure and its steel bars need to be removed in advance, and then the shield machine will be excavated into the shield working shaft. The conventional practice is to reinforce the foundation of the soil behind the tunnel portal so that the strength and stability of the reinforced soil behind the tunnel portal can meet the requirements of self-support, so as to ensure the safety of the tunnel portal when the retaining structure and its steel bars are removed. In karst strata, if the section of the shield tunnel is in the rock layer, there is no need to reinforce the rock behind the tunnel portal, and its strength and stability can also meet the requirements of self-support. However, due to the presence of karst in this part of the rock mass, the interior is filled with karst pipe water or plastic clay, resulting in lateral pressure that is much greater than the lateral pressure of the rock mass, which will cause the tunnel portal to become unstable and collapse.

[0005] In order to deal with the risk of karst to receiving safety during shield tunneling, the conventional practice is to pre-treat the karst behind the tunnel portal before the shield tunneling and receiving. The main treatment methods are grouting or backfilling, that is, using exploration holes to drill holes in the proven karst area, and then grouting or backfilling concrete from the ground to fill the karst cave to form a strong reinforcement body before the shield tunneling, thus avoiding the above-mentioned receiving risks.

[0006] However, it is extremely difficult to accurately determine the distribution of karst and treat it precisely in karst strata with karst development. There are a large number of caves, and there are many "beaded" karsts. It is difficult to accurately determine the distribution of karst. The "carpet-style" search and treatment takes a lot of time and engineering investment, but the treatment effect is difficult to predict. What's more, there are buildings, important municipal pipelines or underground structures on the ground, making it impossible to treat the ground. These difficulties often make conventional karst treatment methods difficult to implement.

[0007] Therefore, under the circumstances of rapid technological development, stringent environmental constraints and high social impact requirements, innovation in receiving methods can enable them to be completed safely, economically and efficiently, which is of great significance to the safe reception of shield machines in karst areas. Summary of the invention

[0008] In view of the above-mentioned defects of the prior art, the present invention provides a shield tunnel construction method using a shield safe receiving channel in karst karst, the purpose of which is to resolve the contradiction between shield receiving in karst karst areas and the difficulties in karst exploration and treatment, and avoid the risks of shield receiving due to karst development.

[0009] To achieve the above-mentioned purpose, the present invention discloses a shield safe receiving channel in karst karst, which is arranged in a shield receiving working shaft; it includes an interface ring beam arranged on the side wall of the shield receiving working shaft, corresponding to the position where the shield tunnel formed by the shield construction enters;

[0010] On the outer side of the side wall of the shield receiving working pit, a bamboo-shaped receiving channel with grid shotcrete as the force bearing system is provided at the position corresponding to the interface ring beam;

[0011] The cross section of one end of the bamboo-shaped receiving channel close to the shield receiving working shaft is a full ring, and the cross section of the other end away from the shield receiving working shaft is a semi-ring, and the semi-ring is completely located above the horizontal plane where the axis of the bamboo-shaped receiving channel is located;

[0012] The bamboo-shaped receiving channel is provided with an end wall toward the direction in which the shield enters;

[0013] The end wall comprises an upper half end wall arranged at the other end portion of the cut bamboo-shaped receiving channel having a semicircular cross section and perpendicular to the axis of the cut bamboo-shaped receiving channel, and a lower half end wall arranged between the semicircular cross section portion and the fully circular cross section portion of the cut bamboo-shaped receiving channel and forming an angle of 120 to 160 degrees with a side of the upper half end wall facing the inner side of the cut bamboo-shaped receiving channel;

[0014] The bamboo-shaped receiving channel is provided with a plurality of system anchor rods on the outer side wall above the horizontal plane where the axis is located;

[0015] The portion of the cut bamboo-shaped receiving channel with a semi-circular cross section close to the horizontal plane where the axis of the cut bamboo-shaped receiving channel is located is provided with a plurality of locking foot anchor rods;

[0016] A pipe shed is provided on the outward side of the upper half end wall;

[0017] A plurality of grouting pipes are arranged between the inner side of the bamboo-shaped receiving channel and the outer wall of the shield tunnel, and the gap between the bamboo-shaped receiving channel and the shield tunnel is filled with grouting through the plurality of grouting pipes;

[0018] An annular end sealing plate is provided on the inner side of the side wall of the shield receiving working shaft, corresponding to the gap between the bamboo-shaped receiving channel and the shield tunnel.

[0019] Preferably, the shield receiving working shaft is an open-cut working shaft.

[0020] Preferably, the length of the fully annular portion of the bamboo-shaped receiving channel cross-section meets the requirements of the shield tunnel's safe receiving operation space and is not less than the length of the three-ring segment of the shield tunnel.

[0021] Preferably, the length of the semi-circular portion of the bamboo-shaped receiving channel having a cross section is set according to the end wall rock fracture angle, that is, the lower half of the tunnel face of the bamboo-shaped receiving channel is set outside the range of the rock fracture angle.

[0022] Preferably, a plurality of the system anchor rods are arranged in a plum blossom shape axially along the bamboo-shaped receiving channel.

[0023] Preferably, a plurality of grouting holes are provided on the side wall of each grouting pipe, which are fixed to the inner side of the bamboo-shaped receiving channel by a fixing member, one end of each grouting pipe is provided with an end stop grouting plugging plate, and the other end is connected to the mouth grouting conduit, and the slurry is obtained through the corresponding mouth grouting conduit;

[0024] Each of the grouting pipes has a diameter of 150 mm;

[0025] Each of the grouting holes has a diameter of 50 mm;

[0026] The interval between each two grouting pipes is 500 mm;

[0027] The multiple grouting pipes are arranged in a plum blossom shape.

[0028] Preferably, the end blocking plate is fixed to the side wall inside the shield receiving working shaft by bolts;

[0029] The side wall inside the shield receiving working shaft is provided with a pre-buried steel plate corresponding to the corresponding end blocking plate;

[0030] The embedded steel plate and the end blocking plate are both provided with a plurality of matching bolt holes;

[0031] The side wall of the embedded steel plate facing the shield receiving working pit is provided with an embedded screw hole corresponding to each of the bolt holes;

[0032] Each of the bolts passes through the corresponding bolt holes on the embedded steel plate and the end blocking plate and is connected to the corresponding embedded screw hole.

[0033] The present invention also provides a shield tunnel construction method using the shield safe receiving channel in the karst karst, comprising the following steps:

[0034] Step 1, constructing the shield receiving working pit, and reserving the position of the interface ring beam according to the size of the bamboo-shaped receiving channel during construction;

[0035] Step 2: using a dark excavation method to excavate the bamboo-shaped receiving channel, as well as the corresponding upper half end wall, lower half end wall, a number of system anchor rods, a number of locking foot anchor rods and a pipe shed;

[0036] Step 3, the shield advances, and when it is 50 meters away from the bamboo-shaped receiving channel, a cross-shaped advance horizontal borehole is drilled, and the borehole length is 30 meters to explore the surrounding rock conditions ahead;

[0037] The arrangement of the M-shaped advanced horizontal drilling is as follows:

[0038] Three are arranged above the palm face of the upper half end wall corresponding to the bamboo-shaped receiving channel, and two are arranged below the palm face of the lower half end wall corresponding to the bamboo-shaped receiving channel;

[0039] If karst is found through the cross-shaped advanced horizontal drilling, advance drilling is carried out in the bamboo-shaped receiving channel, grouting pipes are set, and karst treatment is carried out, and shield advancement is carried out after the treatment is completed;

[0040] Step 4, the shield machine is advanced to the bamboo-shaped receiving channel without stopping, and shield segments are assembled while advancing until it is advanced to the shield receiving working shaft;

[0041] After the shield enters the shield receiving working shaft, the gap between the bamboo-shaped receiving channel and the shield tunnel is closed with the end blocking plate, and the gap between the bamboo-shaped receiving channel and the shield tunnel is filled with grouting through a plurality of grouting pipes;

[0042] Grouting holes are opened on the three rings of pipe segments in front and behind the end of the bamboo-shaped receiving channel excavated by the dark excavation method for secondary grouting. Secondary grouting is carried out through the grouting holes to seal the gaps behind the pipe segments to play a role in blocking water. After ensuring that the sealing is dense, the temporary sealing plate is removed from the tunnel entrance and the tunnel ring beam is constructed.

[0043] Preferably, in step 2, when excavating the bamboo-shaped receiving channel, the excavation size is expanded by more than 20 centimeters than the shield.

[0044] Preferably, the construction process of the grid shotcrete of the bamboo-shaped receiving channel as a force-bearing system is as follows:

[0045] First, assemble the steel frame through the steel frame joints, then spray concrete, and then implement it one by one;

[0046] Among them, the advanced small duct and grouting are used as the stabilization measures of the tunnel face, and the small duct length and spacing are comprehensively arranged. The steel frames are set up every three ducts, and the length is controlled to meet the front and rear overlap of not less than 1 meter;

[0047] The upper end wall is provided with a pipe shed 6m ahead of the end wall to ensure the self-support of the tunnel face, and 30cm of concrete is sprayed on the upper end wall to seal the tunnel face to ensure the stability of the end wall.

[0048] Beneficial effects of the present invention:

[0049] The present invention can solve the contradiction between shield reception and karst exploration and treatment difficulties in karst areas, avoid the risk of shield reception caused by karst development, and complete the construction of shield tunnels in karst areas economically, reasonably, safely and efficiently.

[0050] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The overall arrangement diagram of one embodiment of the present invention is shown.

[0052] Figure 2 A plan view of a receiving channel with a semi-circular cross section and a bamboo-shaped shape in one embodiment of the present invention is shown.

[0053] Figure 3 A vertical view of a bamboo-shaped receiving channel in an embodiment of the present invention is shown.

[0054] Figure 4 A schematic diagram showing the outward viewing direction of the shield receiving working shaft in one embodiment of the present invention is shown.

[0055] Figure 5 A schematic diagram showing the direction of the shield receiving working shaft facing the working shaft viewport in one embodiment of the present invention is shown.

[0056] Figure 6 A plan view of a bamboo-shaped receiving channel with a full ring section in one embodiment of the present invention is shown.

[0057] Figure 7 A longitudinal cross-sectional view of a bamboo-shaped receiving channel in one embodiment of the present invention is shown.

[0058] Figure 8 A cross-sectional view of a fully annular portion of a bamboo-shaped receiving channel in an embodiment of the present invention is shown.

[0059] Fig. 9A cross-sectional view of an annular portion of a bamboo-shaped receiving channel plate in one embodiment of the present invention is shown.

[0060] Fig.10 A cross-sectional view of the first branch of the full annular portion of the bamboo-shaped receiving channel in one embodiment of the present invention is shown.

[0061] Fig.11 A cross-sectional view of the annular portion of a bamboo-shaped receiving channel plate in one embodiment of the present invention is shown.

[0062] Fig.12 A schematic diagram of the arrangement of system anchor rods in one embodiment of the present invention is shown.

[0063] Fig.13 The figure shows the arrangement diagram of the advance support of the bamboo-shaped receiving channel in one embodiment of the present invention.

[0064] Fig.14 A cross-sectional view of the arrangement of grouting pipes in one embodiment of the present invention is shown.

[0065] Fig.15 A large-scale drawing of the fixing of the grouting pipe in one embodiment of the present invention is shown.

[0066] Fig.16 A partial enlarged schematic diagram of a grouting pipe in one embodiment of the present invention is shown.

[0067] Fig.17 A schematic diagram showing the position of the blocking steel plate in one embodiment of the present invention is shown.

[0068] Fig.18 A partial cross-sectional schematic diagram showing the arrangement of embedded steel plates in a shield receiving working shaft in one embodiment of the present invention is shown.

[0069] Fig.19 A partial enlarged schematic diagram of the embedded steel plate in one embodiment of the present invention is shown.

[0070] Fig. 20 A partial cross-sectional schematic diagram of a sealing steel plate installation structure in one embodiment of the present invention is shown.

[0071] Fig.21 A partial enlarged schematic diagram of a sealing steel plate in one embodiment of the present invention is shown.

[0072] Fig. 22 A schematic cross-sectional structure diagram of a shield machine advancing to a bamboo-shaped receiving channel in one embodiment of the present invention is shown.

[0073] Fig.23 A schematic cross-sectional structure diagram of a shield machine advancing to a shield machine receiving working shaft in one embodiment of the present invention is shown.

[0074] Fig.24 A schematic cross-sectional structure diagram showing the completion of grouting filling between a shield tunnel and a bamboo-shaped receiving channel in one embodiment of the present invention is shown. DETAILED DESCRIPTION Example

[0075] like Figures 1 to 14 ,as well as Fig.17 and Fig.24 As shown, a shield receiving safety channel in karst karst is arranged in a shield receiving working shaft 1; it includes an interface ring beam 4 arranged on the side wall of the shield receiving working shaft 1 and corresponding to the position where a shield tunnel 3 formed by the construction of a shield 2 enters;

[0076] On the outer side of the side wall of the shield receiving working shaft 1, a bamboo-shaped receiving channel 5 with grid shotcrete as a force bearing system is provided at the position corresponding to the interface ring beam 4;

[0077] The cross section of the bamboo-shaped receiving channel 5 at one end close to the shield receiving working shaft 1 is a full ring 6, and the cross section of the other end away from the shield receiving working shaft 1 is a semi-ring 7, and the semi-ring 7 is completely located above the horizontal plane where the axis of the bamboo-shaped receiving channel 5 is located;

[0078] The bamboo-shaped receiving channel 5 is provided with an end wall toward the direction in which the shield 2 enters;

[0079] The end wall includes an upper end wall 8 which is arranged at the other end portion of the cut bamboo-shaped receiving channel 5 with a semi-circular cross section 7 and is perpendicular to the axis of the cut bamboo-shaped receiving channel 5, and a lower end wall which is arranged between the part of the cut bamboo-shaped receiving channel 5 with a semi-circular cross section 7 and the part of the cross section 6 and forms an angle of 120 to 160 degrees with a side of the upper end wall 8 facing the inner side of the cut bamboo-shaped receiving channel 5;

[0080] A plurality of system anchor rods 9 are arranged on the outer side wall of the bamboo-shaped receiving channel 5 above the horizontal plane where the axis is located;

[0081] The portion of the bamboo-shaped receiving channel 5 with a semi-circular cross section 7 close to the horizontal plane where the axis of the bamboo-shaped receiving channel 5 is located is provided with a plurality of foot locking anchor rods 10;

[0082] A pipe shed 11 is provided on the outward side of the upper end wall 8;

[0083] A plurality of grouting pipes 12 are arranged between the inner side of the bamboo-shaped receiving channel 5 and the outer wall of the shield tunnel 3, and the gap between the bamboo-shaped receiving channel 5 and the shield tunnel 3 is filled with grout 13 through the plurality of grouting pipes 12;

[0084] An annular end blocking plate 14 is provided on the inner side of the side wall of the shield receiving working shaft 1 , corresponding to the gap between the bamboo-shaped receiving channel 5 and the shield tunnel 3 .

[0085] The principle of the present invention is as follows:

[0086] By setting up a bamboo-shaped dark excavation channel and taking effective in-hole treatment measures, the hidden karst risk behind the working shaft can be transformed into a risk-controllable longitudinal channel for reception. In terms of implementation sequence, the shield working shaft is constructed first, generally by open excavation. The shield tunnel is advanced from the starting shaft to the working shaft. At the same time, a bamboo-shaped dark excavation channel is constructed as a receiving channel. At the end of the channel, advanced measures and end blocking are taken to ensure the safety of the end wall; advanced geological drilling is carried out in the channel to ensure that there is no karst risk in the receiving section. When the shield arrives, it enters the working shaft through the bamboo-shaped dark excavation channel to complete the safe reception of the shield.

[0087] In practical applications, the structure of the bamboo-shaped receiving channel 5 can meet the requirements of the later shield 2 excavation. The upper end wall 8 and the lower end wall of the bamboo-shaped receiving channel 5 are two parts staggered front and back to reduce the area of ​​each part. The advanced upper end wall 8 is ensured to be safe by providing a pipe shed 11 on the outward side. The lower end wall is set to an inclined surface with an angle of 120 to 160 degrees relative to the upper end wall 8, and the heading face of the lower end wall is set outside the rock fracture angle range to achieve self-stabilization.

[0088] In some embodiments, the shield receiving working shaft 1 is an open-cut working shaft.

[0089] In some embodiments, the length of the portion of the bamboo-shaped receiving channel 5 with a full ring cross section 6 meets the requirement of the shield 2 for safe receiving operation space and is not less than the length of the three-ring segment of the shield tunnel 3 .

[0090] In some embodiments, the length of the portion of the semicircular cross-section 7 of the bamboo-shaped receiving channel 5 is set according to the end wall rock fracture angle, that is, the lower half of the tunnel face of the bamboo-shaped receiving channel 5 is set outside the range of the rock fracture angle.

[0091] In some embodiments, a plurality of system anchor rods 9 are arranged in a plum blossom shape axially along the bamboo-shaped receiving channel 5 .

[0092] like Figures 14 to 16 As shown, in some embodiments, a plurality of grouting holes 15 are provided on the side wall of each grouting pipe 12, which are fixed to the inner side of the bamboo-shaped receiving channel 5 by a fixing member 16, and an end stop grouting plugging plate 17 is provided at one end, and the other end is connected to the mouth grouting conduit 24, and the slurry is obtained through the corresponding mouth grouting conduit 24;

[0093] Each grouting pipe 12 has a diameter of 150 mm;

[0094] The diameter of each grouting hole is 50mm;

[0095] Every two grouting pipes 12 are spaced 500 mm apart;

[0096] The plurality of grouting pipes 12 are arranged in a plum blossom shape.

[0097] like Figures 17 to 24 As shown, in some embodiments, the end blocking plate 14 is fixed to the side wall inside the shield receiving working shaft 1 by bolts 18;

[0098] The side wall inside the shield receiving working shaft 1 is provided with a pre-buried steel plate 19 corresponding to the corresponding end blocking plate 14;

[0099] The embedded steel plate 19 and the end blocking plate 14 are both provided with a plurality of matching bolt holes 20;

[0100] The side wall of the embedded steel plate 19 facing the shield receiving working pit 1 is provided with an embedded screw hole 21 corresponding to each bolt hole 20;

[0101] Each bolt 18 passes through a corresponding bolt hole 20 on the embedded steel plate 19 and the end blocking plate 14 and is connected to a corresponding embedded screw hole 21 .

[0102] like Figure 22 to Figure 24 As shown, the present invention also provides a shield tunnel 3 construction method using the above-mentioned shield safe receiving channel in karst karst, comprising the following steps:

[0103] Step 1, constructing a shield receiving working shaft 1, and reserving the position of the interface ring beam 4 according to the size of the bamboo-shaped receiving channel 5 during construction;

[0104] Step 2: using a dark excavation method to excavate and cut the bamboo-shaped receiving channel 5, as well as the corresponding upper half end wall 8, lower half end wall, a number of system anchor rods 9, a number of locking foot anchor rods 10 and a pipe shed 11;

[0105] Step 3: Shield 2 advances. When it is 550 meters away from the bamboo-shaped receiving channel, a M-shaped advance horizontal borehole is drilled with a length of 30 meters to explore the surrounding rock conditions ahead.

[0106] The arrangement of the M-shaped advanced horizontal drilling is as follows:

[0107] Three are arranged above the palm face of the upper end wall 8 corresponding to the bamboo-shaped receiving channel 5, and two are arranged below the palm face of the lower end wall corresponding to the bamboo-shaped receiving channel 5;

[0108] Through the cross-shaped advanced horizontal drilling, if karst is found, advance drilling is carried out in the bamboo-shaped receiving channel 5, and a grouting pipe 12 is set to treat the karst. After the treatment is completed, the shield 2 is advanced;

[0109] Step 4, the shield 2 is advanced to the bamboo-shaped receiving channel 5, and does not stop, while assembling the shield 2 segments, until it is advanced to the shield receiving working shaft 1;

[0110] After the shield 2 enters the shield receiving working shaft 1, the gap between the bamboo-shaped receiving channel 5 and the shield tunnel 3 is closed with an end plugging plate 14, and the gap between the bamboo-shaped receiving channel 5 and the shield tunnel 3 is filled with grout 13 through multiple grouting pipes 12;

[0111] Grouting holes 15 are opened on the three ring segments in front and behind the end of the bamboo-shaped receiving channel 5 excavated by the dark excavation method for secondary grouting. Secondary grouting is carried out through the grouting holes to seal the gaps behind the segments and play a role in blocking water. After ensuring that the sealing is dense, the temporary sealing plate is removed from the hole and the ring beam of the hole is constructed.

[0112] In actual application, three rings of segments are placed before and after the end of the dark excavated channel, and the grouting holes 15 are opened for secondary grouting to ensure that the back of the segments is dense and the underground water channel is blocked.

[0113] In some embodiments, in step 2, when excavating the bamboo-shaped receiving channel, the excavation size is larger than the shield 2 by more than 20 centimeters.

[0114] In actual applications, the above technical means can facilitate the advancement of the shield 2 to the working shaft and smoothly advance it into the bamboo-shaped receiving channel.

[0115] like Fig.13 As shown, in some embodiments, the construction process of the grid shotcrete of the bamboo-shaped receiving channel 5 as a force-bearing system is as follows:

[0116] First, assemble the steel frame through the steel frame joint 23, then spray concrete, and then implement it one by one;

[0117] Among them, the advanced small pipe 22 and grouting are used as the face stabilization measures, and the small pipe 22 is arranged in a coordinated manner in combination with the length and spacing. Every three steel frames are set up, and the length is controlled to meet the front and rear overlap of not less than 1 meter;

[0118] A 6-meter-long pipe shed 11 is arranged outwardly of the upper end wall 8 to ensure the self-support of the tunnel face, and 30 cm of concrete is sprayed on the upper end wall 8 to seal the tunnel face to ensure the stability of the end wall.

[0119] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A shield tunnel construction method using a shield safe receiving channel in karst karst, wherein the shield safe receiving channel in karst karst is arranged in a shield receiving working shaft (1), and the shield safe receiving channel comprises an interface ring beam (4) arranged on the side wall of the shield receiving working shaft (1) and corresponding to the position where a shield tunnel (3) formed by shield construction (2) enters; On the outer side of the side wall of the shield receiving working shaft (1), a bamboo-shaped receiving channel (5) with grid shotcrete as a force-bearing system is provided at a position corresponding to the interface ring beam (4); The cross section of the bamboo-shaped receiving channel (5) at one end close to the shield receiving working shaft (1) is a full ring (6), and the cross section of the other end away from the shield receiving working shaft (1) is a semi-ring (7), and the semi-ring (7) is completely located above the horizontal plane where the axis of the bamboo-shaped receiving channel (5) is located; The bamboo-shaped receiving channel (5) is provided with an end wall in the direction in which the shield (2) enters; The end wall comprises an upper end wall (8) arranged at the other end portion of the cut bamboo-shaped receiving channel (5) having a semi-circular cross section (7), perpendicular to the axis of the cut bamboo-shaped receiving channel (5), and a lower end wall arranged between the portion of the cut bamboo-shaped receiving channel (5) having a semi-circular cross section (7) and the portion of the cut bamboo-shaped receiving channel (5) having a full-circular cross section (6), and forming an angle of 120 to 160 degrees with a side of the upper end wall (8) facing the inner side of the cut bamboo-shaped receiving channel (5); The bamboo-shaped receiving channel (5) is provided with a plurality of system anchor rods (9) on the outer side wall above the horizontal plane where the axis is located; A portion of the bamboo-shaped receiving channel (5) having a semi-circular cross section (7) and close to the horizontal plane where the axis of the bamboo-shaped receiving channel (5) is located is provided with a plurality of foot locking anchor rods (10); A pipe shed (11) is provided on the outward side of the upper half end wall (8); A plurality of grouting pipes (12) are arranged between the inner side of the bamboo-shaped receiving channel (5) and the outer wall of the shield tunnel (3), and a plurality of grouting holes (15) are arranged on the side wall of each grouting pipe (12), so that the gap between the bamboo-shaped receiving channel (5) and the shield tunnel (3) is filled with grouting through the plurality of grouting pipes (12); An annular end blocking plate (14) is provided on the inner side of the side wall of the shield receiving working shaft (1), corresponding to the gap between the bamboo-shaped receiving channel (5) and the shield tunnel (3); The shield tunnel construction method comprises the following steps: Step 1, constructing the shield receiving working shaft (1), and reserving the position of the interface ring beam (4) according to the size of the bamboo-shaped receiving channel (5) during construction; Step 2, using a dark excavation method to excavate the bamboo-shaped receiving channel (5), as well as the corresponding upper end wall (8), lower end wall, a plurality of system anchor rods (9), a plurality of locking foot anchor rods (10) and a pipe shed (11); Step 3, the shield machine (2) advances, and when it is 50 meters away from the bamboo-shaped receiving channel (5), a cross-shaped advance horizontal borehole is drilled, the borehole length is 30 meters, to explore the surrounding rock conditions ahead; The arrangement of the M-shaped advanced horizontal drilling is as follows: Three are arranged above the palm face of the upper end wall (8) corresponding to the bamboo-shaped receiving channel (5), and two are arranged below the palm face of the lower end wall corresponding to the bamboo-shaped receiving channel (5); If karst is found by drilling the cross-shaped advanced horizontal borehole, advance drilling is performed in the bamboo-shaped receiving channel (5), a grouting pipe (12) is installed, and karst treatment is performed. After the treatment is completed, the shield (2) is advanced; Step 4, the shield machine (2) is advanced to the bamboo-shaped receiving channel (5) without stopping, and the shield machine (2) segments are assembled while advancing until it is advanced to the shield machine receiving working shaft (1); After the shield machine (2) enters the shield machine receiving working shaft (1), the gap between the bamboo-shaped receiving channel (5) and the shield tunnel (3) is closed with the end blocking plate (14), and the gap between the bamboo-shaped receiving channel (5) and the shield tunnel (3) is filled with grouting through a plurality of grouting pipes (12); Grouting holes (15) are opened on the three ring segments at the front and rear ends of the bamboo-shaped receiving channel (5) excavated by the dark excavation method to carry out secondary grouting. Secondary grouting is carried out through the grouting holes to seal the gaps behind the segments, thereby playing a role in blocking water. After ensuring that the sealing is dense, the end sealing plate (14) is removed from the hole and the interface ring beam (4) is constructed.

2. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1 is characterized in that: The shield receiving working shaft (1) is an open-cut working shaft.

3. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1 is characterized in that: The length of the portion of the bamboo-shaped receiving channel (5) with a full ring cross section (6) meets the requirements of the shield machine (2) for safe receiving operation space, and is not less than the length of the three-ring segment of the shield tunnel (3).

4. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1 is characterized in that: The length of the portion of the bamboo-shaped receiving channel (5) with a semi-circular cross section (7) is set according to the end wall rock fracture angle, that is, the lower half of the tunnel face of the bamboo-shaped receiving channel (5) is set outside the range of the rock fracture angle.

5. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1 is characterized in that: A plurality of the system anchor rods (9) are arranged in a plum blossom shape axially along the bamboo-shaped receiving channel (5).

6. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1 is characterized in that: Each of the grouting pipes (12) is fixed to the inner side of the bamboo-shaped receiving channel (5) via a fixing member (16), is provided with an end stop grouting plugging plate (17) at one end, and is connected to an opening grouting conduit (24) at the other end, so that grout is obtained through the corresponding opening grouting conduit (24); Each of the grouting pipes (12) has a diameter of 150 mm; Each of the grouting holes (15) has a diameter of 50 mm; The interval between each two grouting pipes (12) is 500 mm; The plurality of grouting pipes (12) are arranged in a plum blossom shape.

7. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1 is characterized in that: The end blocking plate (14) is fixed to the inner side wall of the shield receiving working shaft (1) by means of bolts (18); The side wall inside the shield receiving working shaft (1) is provided with a pre-buried steel plate (19) corresponding to the corresponding end blocking plate (14); The embedded steel plate (19) and the end blocking plate (14) are both provided with a plurality of matching bolt holes (20); A side wall of the embedded steel plate (19) facing the shield receiving working shaft (1) is provided with an embedded screw hole (21) corresponding to each of the bolt holes (20); Each of the bolts (18) passes through the corresponding bolt holes (20) on the embedded steel plate (19) and the end blocking plate (14), and is connected to the corresponding embedded screw hole (21).

8. The shield tunnel construction method using the shield safe receiving channel in karst karst according to claim 1, characterized in that: In the step 2, when the bamboo-shaped receiving channel is excavated, the excavation size is larger than that of the shield (2) by more than 20 centimeters.

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