Reinforcing structure for shield tunnel and reinforcing method for shield tunnel

Abstract

The application discloses a reinforcing structure and a reinforcing method for a shield tunnel, a first rotary jet pile group comprises a plurality of first rotary jet piles, part of the structure of the first rotary jet pile is located above the shield tunnel, and the other part of the structure is located on the side of the shield tunnel; the support pile group comprises a first support pile and a second support pile, the first support pile is located below the shield tunnel, the second support pile is located below the shield tunnel, and the second support pile is arranged on both sides of the first support pile. Thus, by locating part of the structure of the first rotary jet pile above the shield tunnel and locating the first support pile and the second support pile below the shield tunnel, the reinforcement of the upper soil body and the lower soil body of the shield tunnel can be combined, the deformation of the soil body in the shield tunnel construction process is effectively controlled, the stability of the shield tunnel excavation surface is improved, the post-construction settlement of the shield tunnel is reduced, the construction quality of the shield tunnel is improved, the long-term use performance of the shield tunnel is ensured, and the reinforcing structure is convenient for construction and has low construction difficulty.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of civil engineering, in particular to a reinforcing structure for a shield tunnel and a reinforcing method of a shield tunnel. BACKGROUND

[0002] Deep and thick unconsolidated soft soil layers are widely distributed in coastal areas. With the rapid development of cities, more and more shield tunnel projects have to be constructed in this special geological condition. However, unconsolidated soft soil has low strength and large deformation, and often has poor stability before and after the construction of shield tunnels, such as instability of the excavation face, ground deformation, and excessive post-construction settlement, which seriously affect the construction safety and service life of the tunnel.

[0003] In related technologies, in order to ensure the stability during construction and control the long-term settlement of soft soil layers, the soft and weak strata within a certain range around the tunnel need to be pre-reinforced. However, the existing reinforcement scheme is unreasonable, resulting in poor stability of the excavation face during excavation, high risk of water gushing and mud bursting, large post-construction settlement of the tunnel, and easy cracking and leakage of the tunnel segments, which further affects the construction quality and long-term performance of the shield tunnel in unconsolidated soft soil layers. Moreover, the existing reinforcement scheme has high requirements for construction conditions and is difficult to construct. SUMMARY

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present application is to provide a reinforcing structure for a shield tunnel, which can reinforce unconsolidated soft soil layers and effectively control soil deformation, thereby improving the construction quality of the shield tunnel and enhancing the long-term performance of the shield tunnel.

[0005] The present application further provides a reinforcing method of a shield tunnel.

[0006] The reinforcing structure for a shield tunnel according to the present application comprises: a rotary jet pile group, which comprises at least one first rotary jet pile group, the first rotary jet pile group comprising a plurality of first rotary jet piles, the first rotary jet piles having an included angle with a plumb line, part of the structure of the first rotary jet piles being located above the shield tunnel and along the radial direction of the shield tunnel, another part of the structure of the first rotary jet piles being located laterally of the shield tunnel, and the first rotary jet piles being provided on both sides of the shield tunnel; and a support pile group, which comprises first support piles and second support piles, the first support piles being parallel to the plumb line and located below the shield tunnel, the second support piles having an included angle with the plumb line and being located below the shield tunnel and along the radial direction of the shield tunnel, and the second support piles being provided on both sides of the first support piles.

[0007] According to the reinforcing structure for the shield tunnel, the partial structure of the first rotary jet pile is located above the shield tunnel, and the first support pile and the second support pile are both located below the shield tunnel, so that the reinforcement of the upper soil body and the lower soil body of the shield tunnel is combined, the deformation of the soil body in the shield tunnel construction process is effectively controlled, the stability of the shield tunnel excavation surface is improved, the post-construction settlement of the shield tunnel is reduced, the construction quality of the shield tunnel is improved, the long-term use performance of the shield tunnel is ensured, and the reinforcing structure is convenient for construction and has low construction difficulty.

[0008] In some examples of the present application, the rotary jet pile group comprises at least one second rotary jet pile group, the second rotary jet pile group comprises a plurality of second rotary jet piles and a plurality of third rotary jet piles, the second rotary jet pile has an included angle with the plumb line, a partial structure of the second rotary jet pile is located above the shield tunnel and in the radial direction of the shield tunnel, another partial structure of the second rotary jet pile is located laterally of the shield tunnel, the third rotary jet pile is parallel to the plumb line and located above the shield tunnel, and the second rotary jet pile is arranged on both sides of the shield tunnel.

[0009] In some examples of the present application, the shield tunnel and the rotary jet pile group are located in an under-consolidated soft soil layer, the diameter of the shield tunnel is D;

[0010] The thickness of the under-consolidated soft soil layer above the bottom of the shield tunnel is Z1, the included angle between the first rotary jet pile, the second rotary jet pile and the plumb line is α, and the relationship is satisfied: And / or, the thickness of the under-consolidated soft soil layer below the bottom of the shield tunnel is Z2, the included angle between the second support pile and the plumb line is β, and the relationship is satisfied:

[0011] In some examples of the present application, the first rotary jet pile group and the second rotary jet pile group are both multiple, multiple first rotary jet pile groups are sequentially and spaced arranged along the extension direction of the shield tunnel, and one second rotary jet pile group is arranged between every preset number of first rotary jet pile groups.

[0012] In some examples of the present application, the diameters of the first rotary jet pile, the second rotary jet pile and the third rotary jet pile are all A, the interval distance between every adjacent two first rotary jet pile groups and between the adjacent first rotary jet pile group and the second rotary jet pile group is L, the diameter of the shield tunnel is D, and the relationship is satisfied: 1800mm≤L / A≤2400mm.

[0013] In some examples of the present invention, there are multiple support pile groups. Along the extension direction of the shield tunnel, the multiple support pile groups are arranged sequentially at intervals. The interval between each two adjacent support pile groups is 2L, and each support pile group corresponds vertically to the first jet grouting pile group or the second jet grouting pile group.

[0014] In some examples of the present invention, the diameter of the shield tunnel is D, the top width of the first jet grouting pile group and the top width of the second jet grouting pile group are both D, and the bottom width of the first jet grouting pile group and the bottom width of the second jet grouting pile group are both 3D.

[0015] And / or, the diameters of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile are all A, satisfying the relationship: 600mm≤A≤800mm;

[0016] And / or, the cement content of the first jet grouting pile is B, which satisfies the relationship: 15% ≤ B ≤ 20%;

[0017] And / or, the cement content of the second jet grouting pile and the third jet grouting pile is C, satisfying the relationship: 20% ≤ C ≤ 30%;

[0018] And / or, the spacing between the jet grouting piles in the first jet grouting pile group and the second jet grouting pile group is E, satisfying the relationship: 400mm≤E≤600mm, and the interlocking amount of the jet grouting piles in the first jet grouting pile group and the second jet grouting pile group is F, satisfying the relationship: 150mm≤F≤250mm.

[0019] In some examples of the present invention, the shield tunnel and the second support pile are both located in an underconsolidated soft soil layer, a portion of the structure of the first support pile is located in the underconsolidated soft soil layer, and another portion of the structure of the first support pile is located in the bottom bearing layer below the underconsolidated soft soil layer.

[0020] And / or, the diameter of the first support pile is G, which satisfies the relationship: 2000mm≤G≤2500mm;

[0021] And / or, the diameter of the second support pile is H, satisfying the relationship: 1000mm≤H≤1500mm.

[0022] A method for reinforcing a shield tunnel according to the present invention includes: before the shield tunnel is excavated, a jet grouting pile group is driven from the ground surface toward the excavation area of ​​the shield tunnel. The jet grouting pile group includes at least one first jet grouting pile group, the first jet grouting pile group includes multiple first jet grouting piles, the first jet grouting piles have an angle with the vertical line, a part of the structure of the first jet grouting piles is located above the excavation area and along the radial direction of the shield tunnel, another part of the structure of the first jet grouting piles is located on the side of the excavation area, and the first jet grouting piles are present on both sides of the excavation area.

[0023] After the shield tunnel is assembled, support pile groups are constructed through the grouting holes reserved in the tunnel segments. The support pile groups include a first support pile and a second support pile. The first support pile is parallel to the vertical line and located below the shield tunnel. The second support pile has an angle with the vertical line. The second support pile is located below the shield tunnel and along the radial direction of the shield tunnel. The second support pile is provided on both sides of the first support pile.

[0024] In some examples of the present invention, the jet grouting pile group includes at least one second jet grouting pile group, the second jet grouting pile group includes a plurality of second jet grouting piles and a plurality of third jet grouting piles, the second jet grouting piles have an angle with the vertical line, a portion of the structure of the second jet grouting piles is located above the excavation area and along the radial direction of the shield tunnel, another portion of the structure of the second jet grouting piles is located to the side of the excavation area, the third jet grouting piles are parallel to the vertical line and cover the excavation area, and the second jet grouting piles are located on both sides of the excavation area.

[0025] In some examples of the present invention, there are multiple first jet grouting pile groups and multiple second jet grouting pile groups. Along the extension direction of the shield tunnel, multiple first jet grouting pile groups are arranged sequentially at intervals, and a second jet grouting pile group is provided between every predetermined number of first jet grouting pile groups.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0028] Figure 1 This is a cross-sectional view of the reinforcement structure (first jet grouting pile group) according to an embodiment of the present invention;

[0029] Figure 2 This is a cross-sectional view of the reinforcement structure (second jet grouting pile group) according to an embodiment of the present invention;

[0030] Figure 3 This is a cross-sectional view of the reinforced structure according to an embodiment of the present invention from another angle;

[0031] Figure 4 This is a schematic diagram of a portion of the reinforcement structure according to an embodiment of the present invention.

[0032] Figure label:

[0033] Reinforced structure 100; Shield tunnel 99;

[0034] Top fill layer 1; underconsolidated soft soil layer 2; bottom bearing layer 3;

[0035] Jet grouting pile group 10; First jet grouting pile group 11; Second jet grouting pile group 12;

[0036] Support pile group 20; first support pile 21; second support pile 22; grouting hole 23; grouting pipe 24. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0038] The following is for reference. Figures 1-4 A reinforcement structure 100 for a shield tunnel 99 according to an embodiment of the present invention is described.

[0039] like Figures 1-4 As shown, the reinforcement structure 100 for a shield tunnel 99 according to an embodiment of the present invention includes: a jet grouting pile group 10 and a support pile group 20.

[0040] The jet grouting pile group 10 includes at least one first jet grouting pile group 11, which includes multiple first jet grouting piles. The first jet grouting piles are at an angle to the vertical line. Part of the structure of the first jet grouting piles is located above the shield tunnel 99 and along the radial direction of the shield tunnel 99. The other part of the structure of the first jet grouting piles is located on the side of the shield tunnel 99. There are first jet grouting piles on both sides of the shield tunnel 99. The support pile group 20 includes a first support pile 21 and a second support pile 22. The first support pile 21 is parallel to the vertical line and located below the shield tunnel 99. The second support pile 22 is at an angle to the vertical line and is located below the shield tunnel 99 and along the radial direction of the shield tunnel 99. There are second support piles 22 on both sides of the first support pile 21.

[0041] As some embodiments of this application, the jet grouting pile group 10 includes a first jet grouting pile group 11. As some embodiments of this application, the jet grouting pile group 10 includes multiple first jet grouting pile groups 11. The first jet grouting pile group 11 includes first jet grouting piles, and the number of first jet grouting piles can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of first jet grouting piles is six, and all six first jet grouting piles have an angle with the vertical line.

[0042] A portion of the first jet grouting pile structure is located above the shield tunnel 99, and along the radial direction of the shield tunnel 99 (i.e., Figure 1 (As shown in the X direction), another part of the structure of the first jet grouting pile is located on the side of the shield tunnel 99. In other words, some of the first jet grouting piles can be set above and to the left of the shield tunnel 99, and another part of the first jet grouting piles can be set above and to the right of the shield tunnel 99. Multiple first jet grouting piles can form a first jet grouting pile group 11.

[0043] The first support pile 21 is parallel to the vertical line and located below the shield tunnel 99, wherein the vertical line is parallel to the first direction (i.e., Figure 1 The first support pile 21 is parallel to the vertical line (as shown in the Z direction), meaning that the extension direction of the first support pile 21 is parallel to the first direction (i.e., the Z direction is parallel to the vertical line). Figure 1 The Z-direction shown is parallel, and the first support pile 21 is located below the shield tunnel 99.

[0044] The second support pile 22 forms an angle with the vertical line, that is, the second support pile 22 is perpendicular to the first direction (i.e., Figure 1 The second support pile 22 has an angle with the vertical line (shown in the Z direction), and the angle can be, but is not limited to, 45 degrees, 60 degrees, etc. As some embodiments of this application, the angle between the second support pile 22 and the vertical line is 60 degrees. The second support pile 22 is located below the shield tunnel 99, and along the radial direction of the shield tunnel 99 (i.e., Figure 1 (as shown in the X direction), second support piles 22 are provided on both sides of the first support pile 21.

[0045] As some embodiments of this application, before construction, it is necessary to design the pile diameter, reinforcement range, and length of the jet grouting pile group 10 and the support pile group 20 according to the design parameters of the shield tunnel 99. The design parameters of the shield tunnel 99 include, but are not limited to, the diameter, burial depth, geological conditions of the strata it passes through, etc., and determine the angle between the first jet grouting pile, the second jet grouting pile, the second support pile 22 and the vertical line.

[0046] After determining the dimensions, jet grouting pile groups 10 are driven from the ground surface toward the excavation area of ​​the shield tunnel 99. If the jet grouting piles in the jet grouting pile group 10 have an angle with the vertical line, the jet grouting piles can be driven obliquely downward toward the excavation area of ​​the shield tunnel 99 from the ground surface. During construction, construction needs to be carried out according to the designed construction depth and angle to ensure that the angle and depth meet the design requirements. After construction is completed, soil can be backfilled on top of the jet grouting pile group 10 to form the top backfill layer 1. By driving the jet grouting pile group 10 before the excavation of the shield tunnel 99, the stability of the excavation face during the excavation process can be improved.

[0047] Next, the excavation and segment assembly of the shield tunnel 99 are carried out, and grouting holes 23 are reserved for the support pile group 20. After the shield tunnel 99 is assembled, the support pile group 20 is constructed through the grouting holes 23 reserved in the segments of the shield tunnel 99. That is to say, the support pile group 20 can be driven downward into the underconsolidated soft soil layer 2 from the grouting holes 23 reserved in the segments of the assembled shield tunnel 99. As some embodiments of this application, the second support pile 22 enters to half the thickness of the underconsolidated soft soil layer 2 at the bottom of the shield tunnel 99.

[0048] As some embodiments of this application, such as Figure 4 As shown, the grouting holes 23 reserved in the shield tunnel 99 segments can also be used as hoisting holes to avoid secondary openings in the shield tunnel 99, which is beneficial to improving the structural strength of the shield tunnel 99.

[0049] As some embodiments of this application, the grouting pipe 24 is connected to the grouting hole 23 to grout the first support pile 21.

[0050] As some embodiments of this application, the shield tunnel 99 can be divided into multiple tunnel segments. For example, the shield tunnel 99 can be divided into a first tunnel segment, a second tunnel segment, a third tunnel segment, and a fourth tunnel segment, with the first, second, third, and fourth tunnel segments being equidistant. During the construction of the shield tunnel 99, firstly, jet grouting pile groups 10 are installed on the under-consolidated soft soil layer 2 of the first tunnel segment. Then, jet grouting pile groups 10 are installed on the under-consolidated soft soil layer 2 of the second tunnel segment, while simultaneously carrying out the excavation and assembly of the shield tunnel 99 in the first tunnel segment. Then, jet grouting pile groups 10 are installed on the under-consolidated soft soil layer 2 of the third tunnel segment, while simultaneously carrying out the excavation and assembly of the shield tunnel 99 in the second tunnel segment, and simultaneously installing support pile groups 20 on the first tunnel segment. Then, jet grouting pile groups 10 are installed on the underconsolidated soft soil layer 2 of the fourth tunnel section, while the excavation and assembly of the shield tunnel 99 of the third tunnel section are carried out simultaneously, and support pile groups 20 are installed on the second tunnel section. This process significantly improves the construction efficiency of the shield tunnel 99 and significantly shortens the construction period.

[0051] As some embodiments of this application, the length of the first support pile 21 is greater than the length of the second support pile 22, and the support pile group 20 and the jet grouting pile group 10 can form an 'umbrella-shaped support system' to significantly improve the reinforcement effect.

[0052] As some embodiments of this application, pressure sensors and hydraulic connectors are required during the construction of the support pile group 20. The pressure sensor can measure the internal pressure of the shield tunnel 99 from the grouting hole 23. When the pressure sensor measures that the pressure inside the grouting hole 23 is high, the opening size of the grouting hole 23 can be controlled by the hydraulic connector, thereby adjusting the amount of mud discharged, thereby controlling the pressure value range in the soil and reducing the secondary disturbance of the underconsolidated soft soil layer 2 caused by grouting.

[0053] As some embodiments of this application, the support pile group 20 can be constructed inside the segments of the shield tunnel 99 with a diameter of 3.5m or more. The segments of the shield tunnel 99 adopt a unique porous pipe, and a forced grout suction device is provided at the front end of the segments of the shield tunnel 99. The forced grout suction device at the front end can regulate the underground pressure and reduce the risk of secondary disturbance to the underconsolidated soft soil layer 2 caused by grouting.

[0054] It should be noted that the jet grouting pile group 10 is constructed on the ground surface and should be completed before the excavation and segment assembly of the corresponding shield tunnel 99. The construction of the support pile group 20 is carried out after the excavation and segment assembly of the corresponding shield tunnel 99 are completed and there is working space. In conjunction with the above embodiments, it can be understood that after the jet grouting piles are installed on the first tunnel section, the excavation and segment assembly of the first tunnel section can be carried out, and the jet grouting piles of the second tunnel section can be installed at the same time. After the excavation and segment assembly of the shield tunnel 99 in the first tunnel section are completed, the support pile group 20 can be installed below the first tunnel section, and the excavation and segment assembly of the second tunnel section and the construction of the jet grouting pile group 10 above the third tunnel section can be carried out at the same time. This construction method can significantly shorten the construction period and improve construction efficiency.

[0055] Furthermore, the reinforcement structure 100 of this application can significantly improve the stability of the excavation face of the shield tunnel 99, reduce the probability of water inrush and mud inrush in the shield tunnel 99, reduce the probability of segment cracking and leakage in the shield tunnel 99, and also reduce the construction conditions and construction difficulty, ensure the long-term performance of the shield tunnel 99, and effectively extend the service life of the shield tunnel 99.

[0056] Therefore, by positioning part of the first jet grouting pile structure above the shield tunnel 99 and another part to the side of the shield tunnel 99, and placing both the first support pile 21 and the second support pile 22 below the shield tunnel 99, the reinforcement of the soil above and below the shield tunnel 99 can be combined. This effectively controls soil deformation during the construction of the shield tunnel 99, improves the stability of the excavation face of the shield tunnel 99, reduces post-construction settlement of the shield tunnel 99, and is conducive to improving the construction quality of the shield tunnel 99 and ensuring its long-term service performance. Furthermore, the reinforcement structure 100 is easy to construct and has low construction difficulty.

[0057] By arranging the first and second jet grouting piles at an angle to the vertical line, the under-consolidated soft soil layer 2 above the bottom of the shield tunnel 99 can be reinforced. Furthermore, the inclined first and second jet grouting piles can disperse earth pressure, effectively reducing the earth pressure on the top of the shield tunnel 99. Similarly, by arranging the second support pile 22 at an angle to the vertical line, the under-consolidated soft soil layer 2 below the bottom of the shield tunnel 99 can be reinforced, improving the structural strength of the support pile group 20 and further enhancing the structural strength of the shield tunnel 99. Moreover, the inclined second support pile 22 can disperse earth pressure, reducing post-construction settlement of the shield tunnel 99. This arrangement allows the first jet grouting pile group 11, the second jet grouting pile group 12, and the support pile group 20 to form an 'umbrella-shaped support system,' significantly improving the reinforcement effect and enhancing the stability and safety of the shield tunnel 99.

[0058] In some embodiments of the present invention, such asFigure 2 As shown, the jet grouting pile group 10 includes at least one second jet grouting pile group 12, which includes multiple second jet grouting piles and multiple third jet grouting piles. The second jet grouting piles form an angle with the vertical line, and a portion of the structure of the second jet grouting piles is located above the shield tunnel 99 and along the radial direction of the shield tunnel 99 (i.e., Figure 1 (As shown in the X direction), another part of the structure of the second jet grouting pile is located on the side of the shield tunnel 99, and the third jet grouting pile is parallel to the vertical line and located above the shield tunnel 99. There are second jet grouting piles on both sides of the shield tunnel 99.

[0059] As some embodiments of this application, the jet grouting pile group 10 includes a second jet grouting pile group 12. As some embodiments of this application, the jet grouting pile group 10 includes multiple second jet grouting pile groups 12. The second jet grouting pile group 12 includes second jet grouting piles and third jet grouting piles. The number of second jet grouting piles can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of second jet grouting piles is six, and the second jet grouting piles form an angle with the vertical line.

[0060] The number of third jet grouting piles can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of third jet grouting piles is six, and the third jet grouting piles are parallel to the vertical line.

[0061] A portion of the second jet grouting pile structure is located above the shield tunnel 99, and along the radial direction of the shield tunnel 99 (i.e., Figure 1 (As shown in the X direction), another part of the structure of the second jet grouting pile is located on the side of the shield tunnel 99. In other words, part of the second jet grouting pile can be set above and to the left of the shield tunnel 99, and another part of the second jet grouting pile can be set above and to the right of the shield tunnel 99. That is to say, there are second jet grouting piles on both sides of the shield tunnel 99.

[0062] As some embodiments of this application, the second jet grouting pile group 12 can be applied to the reinforcement of the shield tunnel 99, for example, along the extension direction of the shield tunnel 99 (i.e., Figure 3 (as shown in the Y direction), a second jet grouting pile group 12 is provided every five first jet grouting pile groups 11, or every six first jet grouting pile groups 11.

[0063] As some embodiments of this application, when constructing the first jet grouting pile group 11, space needs to be reserved for the shield tunnel 99, that is, the first jet grouting pile group will not cover the excavation area of ​​the shield tunnel 99. When constructing the second jet grouting pile group 12, it can cover the excavation area of ​​the shield tunnel 99.

[0064] This arrangement allows for a reasonable setup of the jet grouting pile group 10, which is beneficial to improving the stability of the jet grouting pile group 10 reinforcement, enhancing the stability of the excavation face during excavation, reducing post-construction settlement of the shield tunnel 99, and improving the construction quality of the shield tunnel 99.

[0065] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, both the shield tunnel 99 and the jet grouting pile group 10 are located in the underconsolidated soft soil layer 2. The diameter of the shield tunnel 99 is D; the thickness of the underconsolidated soft soil layer 2 above the bottom of the shield tunnel 99 is Z1. The angles between the first jet grouting pile, the second jet grouting pile, and the vertical line are both α, satisfying the following relationship:

[0066]

[0067] Among them, the angle α between the first jet grouting pile, the second jet grouting pile and the vertical line satisfies the following relationship: In other words, the arctangent of the ratio of 1.5 times the diameter D of the shield tunnel 99 to the thickness Z1 of the underconsolidated soft soil layer 2 above the bottom of the shield tunnel 99 is the angle α between the first jet grouting pile, the second jet grouting pile and the vertical line.

[0068] As some embodiments of this application, the diameter of the shield tunnel 99 is D, which is 6.2m, and the thickness of the underconsolidated soft soil layer 2 above the bottom of the shield tunnel 99 is Z1, which is 15m. Based on the above data, the included angle between the first jet grouting pile, the second jet grouting pile and the vertical line is determined to be 22.5°.

[0069] This setup can reinforce the underconsolidated soft soil layer 2 above the bottom of the shield tunnel 99, and ensure that the angle between the first jet grouting pile, the second jet grouting pile and the vertical line is reasonable. The inclined first jet grouting pile and the second jet grouting pile can disperse the soil pressure, thereby effectively reducing the soil pressure on the top of the shield tunnel 99.

[0070] In some embodiments of the present invention, such as Figure 1 As shown, the thickness of the underconsolidated soft soil layer 2 below the bottom of the shield tunnel 99 is Z2, and the angle between the second support pile 22 and the vertical line is β, satisfying the following relationship:

[0071] Among them, the angle β between the second support pile 22 and the vertical line satisfies the following relationship: In other words, the arctangent of the ratio of the diameter of shield tunnel 99 to 0.5 times the sum of the diameter of shield tunnel 99 and the thickness Z2 of the underconsolidated soft soil layer 2 below the bottom of shield tunnel 99 is the angle β between the second support pile 22 and the vertical line.

[0072] As some embodiments of this application, the diameter of the shield tunnel 99 is D, which is 6.2m, and the thickness of the underconsolidated soft soil layer 2 below the bottom of the shield tunnel 99 is Z2, which is 9m. Based on the above data, the included angle between the second support pile 22 and the vertical line is determined to be 39.2°.

[0073] This configuration can reinforce the under-consolidated soft soil layer 2 below the bottom of the shield tunnel 99, make the angle of the second support pile 22 reasonable, improve the structural strength of the support pile group 20, further improve the structural strength of the shield tunnel 99, and the inclined second support pile 22 can disperse the soil pressure and reduce the post-construction settlement of the shield tunnel 99.

[0074] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, there are multiple first jet grouting pile groups 11 and second jet grouting pile groups 12, extending along the extension direction of the shield tunnel 99 (i.e., Figure 3 (As shown in the Y direction), multiple first jet grouting pile groups 11 are arranged sequentially at intervals, and a second jet grouting pile group 12 is provided between each preset number of first jet grouting pile groups 11.

[0075] The number of the first jet grouting pile group 11 can be, but is not limited to, ten, twenty, thirty, etc., and the number of the second jet grouting pile group 12 can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of the first jet grouting pile group 11 is twenty, and the number of the second jet grouting pile group 12 is four, along the extension direction of the shield tunnel 99 (i.e., Figure 3 (As shown in the Y direction), twenty first jet grouting pile groups 11 are arranged sequentially at intervals, and a second jet grouting pile group 12 is set between every five first jet grouting pile groups 11.

[0076] As some embodiments of this application, along the extension direction of the shield tunnel 99 (i.e. Figure 3 (As shown in the Y direction), a second jet grouting pile group 12 is set between every six first jet grouting pile groups 11.

[0077] By having multiple first jet grouting pile groups 11 and multiple second jet grouting pile groups 12, and by setting a second jet grouting pile group 12 between each preset number of first jet grouting pile groups 11, it is beneficial to improve the stability of the jet grouting pile group 10 reinforcement, which can significantly enhance the reinforcement effect of the jet grouting pile group 10. Furthermore, this arrangement can reduce construction costs and improve the construction quality of the shield tunnel 99.

[0078] In some embodiments of the present invention, such as Figure 1 and Figure 3As shown, the diameters of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile are all A. The interval between each two adjacent groups of first jet grouting piles 11 and between adjacent groups of first jet grouting piles 11 and second jet grouting piles 12 is L. The diameter of the shield tunnel 99 is D, satisfying the relationship: 1800mm≤L / A≤2400mm.

[0079] In other words, the ratio of L to A can be any value between 1800mm and 2400mm. For example, the ratio of L to A can be, but is not limited to, 1800mm, 2000mm, 2400mm, etc. As some embodiments of this application, the ratio of L to A is 2400mm.

[0080] By setting the ratio of L to A to any value between 1800mm and 2400mm, the ratio of L to A can be made reasonable, thereby improving the reinforcement effect of the jet grouting pile group 10.

[0081] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, there are multiple support pile groups 20, extending along the extension direction of the shield tunnel 99 (i.e., Figure 3 (As shown in the Y direction), multiple support pile groups 20 are arranged sequentially at intervals, with a spacing of 2L between each two adjacent support pile groups 20, and each support pile group 20 corresponds vertically to the first jet grouting pile group 11 or the second jet grouting pile group 12.

[0082] The number of support pile groups 20 can be, but is not limited to, four, five, six, etc., as some embodiments of this application, along the extension direction of the shield tunnel 99 (i.e. Figure 3 (As shown in the Y direction), six support pile groups 20 are arranged in sequence at intervals.

[0083] The interval between any two adjacent support pile groups 20 is 2L. That is, the interval between any two adjacent support pile groups 20 is twice the interval between any two adjacent first jet grouting pile groups 11 and between any two adjacent first jet grouting pile groups 11 and second jet grouting pile groups 12. In other words, a support pile group 20 is set at a distance of 2L.

[0084] Each support pile group 20 corresponds vertically to either the first jet grouting pile group 11 or the second jet grouting pile group 12. In other words, the support pile group 20 can be set to correspond with the first jet grouting pile group 11, or the support pile group 20 can be set to correspond with the second jet grouting pile group 12. In short, the support pile group 20 corresponds vertically to the jet grouting pile group 10.

[0085] This arrangement allows for a reasonable layout of the support pile group 20, which can reliably reinforce the underconsolidated soft soil layer 2 below the bottom of the shield tunnel 99. Furthermore, the support pile group 2 and the corresponding jet grouting pile group 10 can form an arch-like structure, which is beneficial to improving the strength of the underconsolidated soft soil layer 2 where the shield tunnel 99 is located and improving the construction quality of the shield tunnel 99.

[0086] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the diameter of the shield tunnel 99 is D, the top width of the first jet grouting pile group 11 and the top width of the second jet grouting pile group 12 are both D, and the bottom width of the first jet grouting pile group 11 and the bottom width of the second jet grouting pile group 12 are both 3D.

[0087] In other words, the diameter of the shield tunnel 99, the top width of the first jet grouting pile group 11, and the top width of the second jet grouting pile group 12 are all D, and the bottom width of the first jet grouting pile group 11 and the bottom width of the second jet grouting pile group 12 are all 3D. The bottom width of the first jet grouting pile group 11 is three times the diameter of the shield tunnel 99, the bottom width of the first jet grouting pile group 11 is three times the top width of the first jet grouting pile group 11, the bottom width of the first jet grouting pile group 11 is three times the top width of the second jet grouting pile group 12, the bottom width of the second jet grouting pile group 12 is three times the diameter of the shield tunnel 99, the bottom width of the second jet grouting pile group 12 is three times the top width of the first jet grouting pile group 11, and the bottom width of the second jet grouting pile group 12 is three times the top width of the second jet grouting pile group 12.

[0088] This design can significantly improve the stability of the excavation face during the excavation process, which is beneficial to improving the construction quality of the shield tunnel.

[0089] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the diameters of the first, second, and third jet grouting piles are all A, satisfying the relationship: 600mm≤A≤800mm.

[0090] Among them, the diameter A of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile satisfies the relationship 600mm≤A≤800mm. That is to say, the diameter A of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile can be any value between 600mm and 800mm. The diameter A of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile can be, but is not limited to, 600mm, 700mm, 800mm, etc. As some embodiments of this application, the diameter A of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile is 800mm.

[0091] By allowing the diameter A of the first, second, and third jet grouting piles to be any value between 600mm and 800mm, the diameter A of the first, second, and third jet grouting piles can be designed reasonably, taking into account both the construction difficulty and the reinforcement load of the jet grouting pile group 10, which is conducive to improving construction efficiency while ensuring construction quality.

[0092] In some embodiments of the present invention, the cement content of the first jet grouting pile is B, which satisfies the relationship: 15% ≤ B ≤ 20%.

[0093] The cement content B of the first jet grouting pile satisfies the relationship 15%≤B≤20%, that is, the cement content B of the first jet grouting pile can be any value between 15% and 20%. For example, the cement content B of the first jet grouting pile can be, but is not limited to, 15%, 18%, 20%, etc. As some embodiments of this application, the cement content B of the first jet grouting pile is 18%.

[0094] By allowing the cement content B of the first jet grouting pile to be any value between 15% and 20%, the cement content of the first jet grouting pile can be made reasonable, which can improve the structural strength of the first jet grouting pile and is beneficial to improving the reinforcement performance of the first jet grouting pile group 11.

[0095] In some embodiments of the present invention, the cement content of the second jet grouting pile and the third jet grouting pile is C, which satisfies the relationship: 20% ≤ C ≤ 30%.

[0096] The cement content C of the second and third jet grouting piles satisfies the relationship 20% ≤ C ≤ 30%. That is, the cement content C of the second and third jet grouting piles can be any value between 20% and 30%. For example, the cement content C of the second and third jet grouting piles can be, but is not limited to, 20%, 25%, 30%, etc. As some embodiments of this application, the cement content C of the second and third jet grouting piles is 25%.

[0097] By setting the cement content C of the second and third jet grouting piles to any value between 20% and 30%, the cement content of the second and third jet grouting piles can be made reasonable, which can improve the structural strength of the second and third jet grouting piles and is beneficial to improving the reinforcement performance of the second jet grouting pile group 12.

[0098] In some embodiments of the present invention, the spacing between the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 is E, satisfying the relationship: 400mm≤E≤600mm, and the interlocking amount of the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 is F, satisfying the relationship: 150mm≤F≤250mm.

[0099] In this embodiment, the spacing between the jet grouting piles in the first jet grouting pile group 11 is E, and the spacing between the jet grouting piles in the second jet grouting pile group 12 is E. E satisfies the relationship 400mm≤E≤600mm. That is to say, the spacing E between the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 can be any value between 400mm and 600mm. For example, the spacing E between the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 can be, but is not limited to, 400mm, 500mm, 600mm, etc. As some embodiments of this application, the spacing E between the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 is 600mm.

[0100] The engagement amount of the jet grouting piles in the first jet grouting pile group 11 is F, and the engagement amount of the jet grouting piles in the second jet grouting pile group 12 is F. F satisfies the relationship 150mm≤F≤250mm. That is to say, the engagement amount F of the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 can be any value between 150mm and 250mm. For example, the engagement amount F of the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 can be, but is not limited to, 150mm, 200mm, 250mm, etc. As some embodiments of this application, the engagement amount F of the jet grouting piles in the first jet grouting pile group 11 and the second jet grouting pile group 12 is 200mm.

[0101] This configuration allows for a reasonable spacing and interlocking amount of the jet grouting piles in the jet grouting pile group 10, which can significantly improve the structural strength and reinforcement performance of the jet grouting pile group 10, effectively enhance the stability of the excavation face during excavation, and effectively reduce the post-construction settlement of the shield tunnel 99.

[0102] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the shield tunnel 99 and the second support pile 22 are both located in the underconsolidated soft soil layer 2. Part of the structure of the first support pile 21 is located in the underconsolidated soft soil layer 2, and another part of the structure of the first support pile 21 is located in the bottom bearing layer 3 below the underconsolidated soft soil layer 2.

[0103] As some embodiments of this application, the length of another part of the structure of the first support pile 21 extending into the bottom bearing layer 3 can be, but is not limited to, 0.8m, 1m, etc.

[0104] This design allows for a reasonable design of the first support pile 21. By inserting a portion of the structure of the first support pile 21 into the bottom bearing layer 3, the shield tunnel 99 can be effectively supported by the first support pile 21, significantly reducing the post-construction settlement of the shield tunnel 99.

[0105] In some embodiments of the present invention, the diameter of the first support pile 21 is G, which satisfies the relationship: 2000mm≤G≤2500mm.

[0106] The diameter G of the first support pile 21 satisfies the relationship 2000mm≤G≤2500mm. That is, the diameter G of the first support pile 21 can be any value between 2000mm and 2500mm. For example, the diameter G of the first support pile 21 can be, but is not limited to, 2000mm, 2200mm, 2500mm, etc. As some embodiments of this application, the diameter G of the first support pile 21 is 2200mm.

[0107] By setting the diameter G of the first support pile 21 to any value between 2000mm and 2500mm, the diameter design of the first support pile 21 can be made reasonable, which can improve the structural strength of the first support pile 21 and enable the first support pile 21 to effectively support the shield tunnel 99.

[0108] In some embodiments of the present invention, the diameter of the second support pile 22 is H, satisfying the relationship: 1000mm≤H≤1500mm.

[0109] The diameter H of the second support pile 22 satisfies the relationship 1000mm≤H≤1500mm. That is, the diameter H of the second support pile 22 can be any value between 1000mm and 1500mm. For example, the diameter H of the second support pile 22 can be, but is not limited to, 1000mm, 1200mm, 1500mm, etc. As some embodiments of this application, the diameter H of the second support pile 22 is 1200mm.

[0110] By setting the diameter H of the second support pile 22 to any value between 1000mm and 1500mm, the diameter of the second support pile 22 can be designed reasonably, thereby improving the structural strength of the second support pile 22 and enhancing the support performance of the support pile group 20.

[0111] According to the present invention, a method for reinforcing a shield tunnel includes: before the shield tunnel is excavated, jet grouting pile groups are driven from the ground surface toward the excavation area of ​​the shield tunnel. The jet grouting pile group includes at least one first jet grouting pile group, and the first jet grouting pile group includes multiple first jet grouting piles. The first jet grouting piles have an angle with the vertical line. Part of the structure of the first jet grouting piles is located above the excavation area and along the radial direction of the shield tunnel. Another part of the structure of the first jet grouting piles is located on the side of the excavation area. There are first jet grouting piles on both sides of the excavation area.

[0112] After the shield tunnel is assembled, support pile groups are constructed through the grouting holes reserved in the tunnel segments. The support pile group includes a first support pile and a second support pile. The first support pile is parallel to the vertical line and located below the shield tunnel. The second support pile has an angle with the vertical line and is located below the shield tunnel along the radial direction of the shield tunnel. Second support piles are provided on both sides of the first support pile.

[0113] As some embodiments of this application, a jet grouting pile group includes a first jet grouting pile group; as some embodiments of this application, a jet grouting pile group includes multiple first jet grouting pile groups. A first jet grouting pile group includes first jet grouting piles, and the number of first jet grouting piles can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of first jet grouting piles is six, and all six first jet grouting piles form an angle with the vertical line.

[0114] A portion of the first jet grouting pile structure is located above the shield tunnel, and along the radial direction of the shield tunnel (i.e., Figure 1 (As shown in the X direction), another part of the structure of the first jet grouting pile is located on the side of the shield tunnel. In other words, some of the first jet grouting piles can be set above and to the left of the shield tunnel, and another part of the first jet grouting piles can also be set above and to the right of the shield tunnel. Multiple first jet grouting piles can form a first jet grouting pile group.

[0115] As some embodiments of this application, before construction, it is necessary to design the pile diameter, reinforcement range, and length of the jet grouting pile group and the support pile group according to the design parameters of the shield tunnel. The design parameters of the shield tunnel include, but are not limited to, the diameter of the shield tunnel, the burial depth, the geological conditions of the strata it passes through, etc., and determine the size of the angle between the first jet grouting pile, the second jet grouting pile, the second support pile and the vertical line.

[0116] After determining the dimensions, jet grouting pile groups are driven from the ground surface toward the excavation area of ​​the shield tunnel. If the jet grouting piles in the jet grouting pile group have an angle with the vertical line, the jet grouting piles can be driven diagonally downwards from the ground surface toward the excavation area of ​​the shield tunnel. During construction, it is necessary to carry out construction according to the designed construction depth and angle to ensure that the angle and depth meet the design requirements. After construction is completed, soil can be backfilled on top of the jet grouting pile group to form a top backfill layer. By driving jet grouting pile groups before the shield tunnel is excavated, the stability of the excavation face during the excavation process can be improved.

[0117] Next, the excavation and segment assembly of the shield tunnel are carried out, and grouting holes are reserved for the support pile group. After the shield tunnel is assembled, the support pile group is constructed through the grouting holes reserved in the shield tunnel segments. That is to say, the support pile group can be driven into the underconsolidated soft soil layer from the grouting holes reserved in the assembled shield tunnel segments. As some embodiments of this application, the second support pile enters to half the thickness of the underconsolidated soft soil layer at the bottom of the shield tunnel.

[0118] As some embodiments of this application, the grouting holes reserved in the shield tunnel segments can also be used as hoisting holes, avoiding secondary openings in the shield tunnel and improving the structural strength of the shield tunnel.

[0119] As some embodiments of this application, such as Figure 4 As shown, the grouting pipe is connected to the grouting hole to inject grout into the first support pile.

[0120] The first support pile is parallel to the plumb line and located below the shield tunnel, wherein the plumb line is parallel to the first direction (i.e., Figure 1 The first support pile is parallel to the Z direction (as shown), and the extension direction of the first support pile is parallel to the vertical line. That is to say, the extension direction of the first support pile is parallel to the first direction (i.e., the Z direction is parallel to the vertical line). Figure 1 The Z-direction shown is parallel, and the first support pile is located below the shield tunnel.

[0121] The second support pile forms an angle with the vertical line, meaning the second support pile is perpendicular to the first direction (i.e., Figure 1 The second support pile (in the Z direction shown) has an angle, the size of which can be, but is not limited to, 45 degrees, 60 degrees, etc. As some embodiments of this application, the angle between the second support pile and the vertical line is 60 degrees. The second support pile is located below the shield tunnel and, along the radial direction of the shield tunnel (i.e., Figure 1 (As shown in the X direction), second support piles are provided on both sides of the first support pile.

[0122] As some embodiments of this application, the length of the first support pile is greater than the length of the second support pile, and the support pile group and the jet grouting pile group can form an 'umbrella-shaped support system' to significantly improve the reinforcement effect.

[0123] As some embodiments of this application, pressure sensors and hydraulic connectors are required during the construction of the support pile group. The pressure sensor can measure the pressure inside the tunnel from the grouting hole. When the pressure sensor measures that the pressure inside the grouting hole is high, the hydraulic connector can be used to control the opening size of the grouting hole, thereby adjusting the amount of mud discharged, thereby controlling the pressure value range inside the soil and reducing the secondary disturbance of grouting to the underconsolidated soft soil layer.

[0124] As some embodiments of this application, the support pile group can be constructed inside the segments of a shield tunnel with a diameter of 3.5m or more. The segments of the shield tunnel adopt a unique porous pipe, and a forced grout suction device is installed at the front end of the shield tunnel segments. The forced grout suction device at the front end can regulate the underground pressure and reduce the risk of secondary disturbance to the bottom soft soil caused by grouting.

[0125] Therefore, by placing part of the first jet grouting pile structure above the shield tunnel and another part beside it, and placing both the first and second support piles below the shield tunnel, the reinforcement of the soil above and below the shield tunnel can be combined. This effectively controls soil deformation during shield tunnel construction, improves the stability of the shield tunnel excavation face, reduces post-construction settlement, and contributes to improving the construction quality and ensuring the long-term performance of the shield tunnel. Furthermore, the reinforcement structure is easy to construct and has low construction difficulty.

[0126] In some embodiments of the present invention, such asFigure 2 As shown, the jet grouting pile group includes at least one second jet grouting pile group, which includes multiple second jet grouting piles and multiple third jet grouting piles. The second jet grouting piles have an angle with the vertical line. Part of the structure of the second jet grouting piles is located above the excavation area and along the radial direction of the shield tunnel. Another part of the structure of the second jet grouting piles is located on the side of the excavation area. The third jet grouting piles are parallel to the vertical line and cover the excavation area. There are second jet grouting piles on both sides of the excavation area.

[0127] As some embodiments of this application, the jet grouting pile group includes a second jet grouting pile group; as some embodiments of this application, the jet grouting pile group includes multiple second jet grouting pile groups. The second jet grouting pile group includes second jet grouting piles and third jet grouting piles. The number of second jet grouting piles can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of second jet grouting piles is six, and the second jet grouting piles form an angle with the vertical line.

[0128] The number of third jet grouting piles can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of third jet grouting piles is six, and the third jet grouting piles are parallel to the vertical line.

[0129] Part of the second jet grouting pile structure is located above the shield tunnel, and along the radial direction of the shield tunnel (i.e., Figure 1 (As shown in the X direction), another part of the structure of the second jet grouting pile is located on the side of the shield tunnel. In other words, some of the second jet grouting piles can be set above and to the left of the shield tunnel, and another part of the second jet grouting piles can be set above and to the right of the shield tunnel. That is to say, there are second jet grouting piles on both sides of the shield tunnel.

[0130] As some embodiments of this application, the second jet grouting pile group can be applied to the reinforcement of shield tunnels, for example, along the extension direction of the shield tunnel (i.e., Figure 3 (As shown in the Y direction), a second jet grouting pile group is set every five first jet grouting pile groups, or every six first jet grouting pile groups.

[0131] As some embodiments of this application, when constructing the first jet grouting pile group, space needs to be reserved for the shield tunnel, that is, the first jet grouting pile group will not cover the excavation area of ​​the shield tunnel, while when constructing the second jet grouting pile group, it can cover the excavation area of ​​the shield tunnel.

[0132] This setup allows for a reasonable arrangement of jet grouting pile groups, which helps improve the stability of the jet grouting pile reinforcement, enhances the stability of the excavation face during excavation, reduces post-construction settlement of the shield tunnel, and ultimately improves the construction quality of the shield tunnel.

[0133] In some embodiments of the present invention, such as Figures 1-3As shown, both the first and second jet grouting pile groups consist of multiple piles, extending along the direction of the shield tunnel (i.e.,...). Figure 3 (As shown in the Y direction), multiple first jet grouting pile groups are arranged sequentially at intervals, and a second jet grouting pile group is set between each preset number of first jet grouting pile groups.

[0134] The number of the first jet grouting pile group can be, but is not limited to, ten, twenty, thirty, etc., and the number of the second jet grouting pile group can be, but is not limited to, six, eight, ten, etc. As some embodiments of this application, the number of the first jet grouting pile group is twenty, and the number of the second jet grouting pile group is four, along the extension direction of the shield tunnel (i.e., Figure 3 (As shown in the Y direction), twenty first jet grouting pile groups are arranged sequentially at intervals, and a second jet grouting pile group is set every five first jet grouting pile groups.

[0135] This arrangement allows for a reasonable setup of the first and second jet grouting pile groups, which is beneficial for improving the reinforcement performance of the jet grouting pile groups and significantly enhancing their reinforcement effect. Furthermore, this arrangement can reduce construction costs and improve the construction quality of shield tunnels.

[0136] As some embodiments of this application, the jet grouting pile assembly construction, shield tunnel excavation, and support pile assembly construction are carried out simultaneously.

[0137] During the construction of jet grouting pile groups, the excavation of shield tunnels can be carried out simultaneously, and the assembled shield tunnels can be placed into the excavation area and the support pile groups can be constructed at the same time.

[0138] As some embodiments of this application, the total length of the shield tunnel can be divided into multiple tunnel segments. For example, the total length of the shield tunnel can be divided into a first tunnel segment, a second tunnel segment, a third tunnel segment, and a fourth tunnel segment, with the first, second, third, and fourth tunnel segments being equidistant. During the shield tunnel construction process, firstly, jet grouting piles are installed in the under-consolidated soft soil strata of the first tunnel segment. Then, jet grouting piles are installed in the under-consolidated soft soil strata of the second tunnel segment, while simultaneously excavating and assembling the shield tunnel of the first tunnel segment. Then, jet grouting piles are installed in the under-consolidated soft soil strata of the third tunnel segment, while simultaneously excavating and assembling the shield tunnel of the second tunnel segment, and simultaneously installing support piles in the first tunnel segment. Then, jet grouting piles are installed in the under-consolidated soft soil strata of the fourth tunnel segment, while simultaneously excavating and assembling the shield tunnel of the third tunnel segment, and simultaneously installing support piles in the second tunnel segment. Then, the excavation and assembly of the shield tunnel for the fourth tunnel section were carried out, while the support piles for the third tunnel section were installed simultaneously. Finally, the support piles for the fourth tunnel section were installed.

[0139] This setup allows for a more rational construction process for shield tunnels, significantly reduces the construction cycle, makes better use of construction time, and improves construction efficiency.

[0140] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0141] In the description of this invention, "first feature" and "second feature" may include one or more of the features.

[0142] In the description of this invention, "a plurality of" means two or more.

[0143] In the description of this invention, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or it may include the first and second features not being in direct contact but being in contact through another feature between them.

[0144] In the description of this invention, the terms "above," "over," and "on top" for the first feature and the second feature include the first feature being directly above or diagonally above the second feature, or simply indicating that the first feature is at a higher horizontal level than the second feature.

[0145] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0146] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A reinforcement structure for a shield tunnel, characterized by, include: A jet grouting pile group, the jet grouting pile group including at least one first jet grouting pile group, the first jet grouting pile group including multiple first jet grouting piles, the first jet grouting piles having an angle with the vertical line, a part of the structure of the first jet grouting piles being located above the shield tunnel and along the radial direction of the shield tunnel, another part of the structure of the first jet grouting piles being located on the side of the shield tunnel, and the shield tunnel having first jet grouting piles on both sides. The support pile group includes a first support pile and a second support pile. The first support pile is parallel to the vertical line and located below the shield tunnel. The second support pile has an angle with the vertical line and is located below the shield tunnel along the radial direction of the shield tunnel. The second support pile is provided on both sides of the first support pile. The jet grouting pile group also includes at least one second jet grouting pile group, which includes multiple second jet grouting piles and multiple third jet grouting piles. The second jet grouting piles have an angle with the vertical line. Part of the structure of the second jet grouting piles is located above the shield tunnel and along the radial direction of the shield tunnel. Another part of the structure of the second jet grouting piles is located on the side of the shield tunnel. The third jet grouting piles are parallel to the vertical line and located above the shield tunnel. The shield tunnel has second jet grouting piles on both sides. The shield tunnel and the jet grouting pile group are located in an underconsolidated soft soil layer, and the diameter of the shield tunnel is D; The thickness of the soft soil layer above the shield tunnel bottom is Z 1, the included angle between the first rotary jet pile, the second rotary jet pile and the plumb line is α, and the relationship is satisfied: ; the thickness of the soft soil layer below the shield tunnel bottom is Z 2, the included angle between the second support pile and the plumb line is β, and the relationship is satisfied: .

2. The reinforcement structure for a shield tunnel according to claim 1, characterized in that, There are multiple first jet grouting pile groups and multiple second jet grouting pile groups. Along the extension direction of the shield tunnel, multiple first jet grouting pile groups are arranged in sequence at intervals, and a second jet grouting pile group is set between every preset number of first jet grouting pile groups.

3. The reinforcement structure for a shield tunnel according to claim 2, characterized in that, The diameters of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile are all A. The interval between each two adjacent groups of the first jet grouting piles and between adjacent groups of the first and second jet grouting piles is L. The diameter of the shield tunnel is D, satisfying the relationship: 1800mm≤L / A≤2400mm.

4. The reinforcement structure for a shield tunnel according to claim 3, characterized in that, There are multiple support pile groups. Along the extension direction of the shield tunnel, the multiple support pile groups are arranged in sequence at intervals. The interval between each two adjacent support pile groups is 2L, and each support pile group corresponds vertically to the first jet grouting pile group or the second jet grouting pile group.

5. The reinforcement structure for a shield tunnel according to claim 1, wherein The diameter of the shield tunnel is D, the top width of the first jet grouting pile group and the top width of the second jet grouting pile group are both D, and the bottom width of the first jet grouting pile group and the bottom width of the second jet grouting pile group are both 3D. And / or, the diameters of the first jet grouting pile, the second jet grouting pile, and the third jet grouting pile are all A, satisfying the relationship: 600mm≤A≤800mm; And / or, the cement content of the first jet grouting pile is B, satisfying the relationship: 15%≤B≤20%; And / or, the cement content of the second jet grouting pile and the third jet grouting pile is C, satisfying the relationship: 20%≤C≤30%; And / or, the distance between the rotary jet piles in the first rotary jet pile group and the second rotary jet pile group is E, satisfying the relationship 400mm≤E≤600mm, and the rotary jet pile engagement amount in the first rotary jet pile group and the second rotary jet pile group is F, satisfying the relationship 150mm≤F≤250mm.

6. The reinforcement structure for a shield tunnel according to any one of claims 1 to 5, characterized in that, The shield tunnel and the second support pile are located in an unconsolidated soft soil layer, and part of the structure of the first support pile is located in the unconsolidated soft soil layer, and another part of the structure of the first support pile is located in a bottom bearing layer below the unconsolidated soft soil layer. And / or, the diameter of the first support pile is G, satisfying the relationship 2000mm≤G≤2500mm. And / or, the diameter of the second support pile is H, satisfying the relationship 1000mm≤H≤1500mm.

7. A reinforcing method of a shield tunnel to which a reinforcing structure is applied, characterized by, The reinforcement structure is the reinforcement structure for a shield tunnel according to any one of claims 1-6, and the reinforcement method comprises: Before the shield tunnel is excavated, a rotary jet pile group is driven from the ground surface towards an excavation area of the shield tunnel, the rotary jet pile group comprising at least one first rotary jet pile group, the first rotary jet pile group comprising a plurality of first rotary jet piles, the first rotary jet piles having an angle with a plumb line, part of the structure of the first rotary jet piles being located above the excavation area and along the radial direction of the shield tunnel, and another part of the structure of the first rotary jet piles being located to the side of the excavation area, both sides of the excavation area having the first rotary jet piles, the rotary jet pile group further comprising at least one second rotary jet pile group, the second rotary jet pile group comprising a plurality of second rotary jet piles and a plurality of third rotary jet piles, the second rotary jet piles having an angle with the plumb line, part of the structure of the second rotary jet piles being located above the excavation area and along the radial direction of the shield tunnel, and another part of the structure of the second rotary jet piles being located to the side of the excavation area, the third rotary jet piles being parallel to the plumb line and covering the excavation area, both sides of the excavation area having the second rotary jet piles; After the shield tunnel is assembled, a support pile group is constructed through a grouting hole reserved in a segment of the shield tunnel, the support pile group comprising a first support pile and a second support pile, the first support pile being parallel to the plumb line and located below the shield tunnel, the second support pile having an angle with the plumb line, the second support pile being located below the shield tunnel and along the radial direction of the shield tunnel, both sides of the first support pile being provided with the second support pile.

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