Shield receiving well end reinforcing structure under limited condition and construction method and using method thereof

Abstract

The shield receiving well end reinforcing structure under the limited condition comprises arched jet grouting piles and bottom jet grouting piles, the to-be-reinforced wall on the outer side of an underground diaphragm wall of a shield receiving well is provided with the arched jet grouting piles which are meshed or overlapped with one another, and the arched jet grouting piles comprise a plurality of jet grouting piles which are vertically arranged and meshed or overlapped with one another; a plurality of arch-shaped jet grouting piles are arranged in an arch shape, an opening of the arch shape faces a wall to be reinforced, the arch-shaped end portions of the arch-shaped jet grouting piles are connected with the wall to be reinforced, and the bottom between the arch-shaped jet grouting piles of the wall to be reinforced and the wall to be reinforced is filled with a bottom jet grouting pile composed of a plurality of jet grouting piles which are meshed or overlapped with one another. And a shield tunneling machine can pass through the upper part of the bottom jet grouting pile. The thrust of the shield tunneling machine can be dispersed through the arrangement of the arched jet grouting piles, the bottom jet grouting piles are arranged as supports, the reinforcing effect can be guaranteed, and meanwhile contact or interference with a constraint object can be reasonably avoided through a smaller occupied area.

Description

Technical Field

[0001] The invention belongs to the technical field of dark-digging tunnel construction, and in particular relates to a shield receiving shaft end reinforcement structure under restricted conditions and a construction method and a use method thereof. Background Art

[0002] In some drainage tunnel projects, several drainage tunnels need to be constructed. The common tunnel inner diameter is 6800mm, the tunnel segment thickness is 450mm, the ring width is 1500mm, and all are constructed using the shield method. The plane of the shield receiving well under construction is a regular rectangle, and the common effective height in the well is 22.65m. The foundation pit support uses an underground continuous wall with a thickness of 1.0m as the supporting structure. The ground-connected wall is 43.85m long, and double-tube rotary jet piles are set to reinforce the trench wall. The shield tunnel arch is buried at a depth of about 13m and the bottom is buried at a depth of 20.7m.

[0003] According to the conventional method, the plane reinforcement area of ​​the gate well end of the shield tunnel receiving well is 12m long, 13.7m wide and 13.7m deep along the tunnel direction. The tunnel segment is 3m up and down and left and right. The reinforcement method is double-tube high-pressure jet grouting piles, and the specific arrangement is a rectangular arrangement, that is, Figure 7 The rectangular jet-jet piles 14 shown are used to reinforce the two ends of the two drainage tunnels with 780 jet-jet piles each.

[0004] However, when there is a high-voltage transmission line above the part of the construction area where the gate well end of the receiving well is reinforced, due to the safety distance limit of the high-voltage transmission line, the conventional reinforcement method will inevitably cause the construction machinery to invade the safety distance of the high-voltage line, causing safety hazards and making it impossible to carry out construction according to the conventional plan; or, when there is a relocated water supply pipeline underground in the area, due to the burial depth limit of the water supply pipeline, the conventional reinforcement method will cause the lower water pipe to occupy the reinforced area, making it impossible to carry out construction in the reinforced area according to the conventional plan; Figure 8 As shown, when it is impossible to carry out construction according to the conventional reinforcement method, simply shortening the reinforcement area will lead to reduced reinforcement effect at the end of the receiving shaft, and the stability requirements of the shield receiving the broken hole door cannot be guaranteed, thus failing to meet the construction needs of the shield receiving.

[0005] Therefore, there is an urgent need for a shield receiving shaft end reinforcement structure under restricted conditions and its construction method and use method to solve the problem that the width of the reinforcement area is limited during the construction of the conventional shield receiving shaft end reinforcement structure due to obstacles, and the reinforcement effect of the receiving shaft end cannot be guaranteed. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a shield receiving shaft end reinforcement structure under restricted conditions and a construction method and a use method thereof, so as to solve the problem that during the construction process of the conventional shield receiving shaft end reinforcement structure, when it is affected by obstacles, the width of the reinforcement area is limited and the reinforcement effect of the receiving shaft end cannot be guaranteed.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A shield receiving shaft end reinforcement structure under restricted conditions, characterized in that it includes several rows of arched rotary jet piles and bottom rotary jet piles, and the outer side of the ground-connected wall of the shield receiving shaft to be reinforced wall is provided with several rows of mutually interlocking or overlapping arched rotary jet piles from near to far, each row of the arched rotary jet piles includes several vertically arranged and mutually interlocking or overlapping rotary jet piles, and several rotary jet piles of the arched rotary jet piles are arranged in an arch shape, and the opening of the arch faces the wall to be reinforced, and the arched ends of the several rows of arched rotary jet piles are connected to the wall to be reinforced, and the bottom between the arched rotary jet pile closest to the wall to be reinforced and the wall to be reinforced is filled with bottom rotary jet piles composed of several mutually interlocking or overlapping rotary jet piles, and the top of the bottom rotary jet piles can be used for the shield machine to pass.

[0008] To optimize the above technical solutions, the specific measures taken also include: Furthermore, it also includes straight-row rotary jet piles, and the outer side of the ground-connected wall of the shield receiving shaft is provided with straight-row rotary jet piles that are interlocked or overlapped with each other on the wall to be reinforced. The straight-row rotary jet piles include several rotary jet piles that are vertically arranged and interlocked or overlapped with each other, and several rotary jet piles of the straight-row rotary jet piles are interlocked or overlapped with the wall to be reinforced, and the ends of several rows of the arched rotary jet piles are connected to the wall through the straight-row rotary jet piles, and the bottom rotary jet piles are connected to the straight-row rotary jet piles close to the side of the wall to be reinforced.

[0009] Furthermore, the upper ends of several rotary jet piles of the bottom rotary jet piles are flush with each other.

[0010] Furthermore, the bottom jet grouting piles are composed of several jet grouting piles of different heights, and the upper ends of the bottom jet grouting piles are arc-shaped grooves that are consistent with the curvature of the outer side of the shield machine, and the axial direction of the arc-shaped groove is consistent with the axial direction of the shield machine.

[0011] Furthermore, it also includes a dewatering well, which is arranged between the shield excavation routes of several tunnels and is arranged on a side close to the shield receiving well.

[0012] Furthermore, the dewatering wells are also arranged on the seaward side of the shield excavation routes of several tunnels.

[0013] Furthermore, a construction method of a shield receiving shaft end reinforcement structure under the above-mentioned restricted conditions is characterized by comprising the following steps: At the wall to be reinforced outside the ground-connected wall of the shield receiving shaft, several rotary jet piles are arranged according to preset dimensions to form a bottom rotary jet pile. The side of the bottom rotary jet pile away from the wall to be reinforced is arc-shaped, and several rows of mutually interlocking or overlapping arched rotary jet piles are arranged from near to far on one side of the arc of the bottom rotary jet pile. Both ends of the rows of arched rotary jet piles are connected to the wall to be reinforced, and a gap is reserved between the top of the bottom rotary jet pile and the top of the arched rotary jet pile for the shield machine to pass through.

[0014] Furthermore, the method also includes the following steps: setting a number of rotary jet piles according to preset sizes to form a bottom rotary jet pile, setting a number of mutually interlocking or overlapping rotary jet piles between the side of the bottom rotary jet pile close to the wall to be reinforced and the wall to be reinforced to form a straight row of rotary jet piles that are respectively interlocked or overlapped with the bottom rotary jet piles and the wall to be reinforced, and both ends of the several rows of arched rotary jet piles are interlocked or overlapped with the straight row of rotary jet piles.

[0015] Furthermore, dewatering wells are respectively set up between the shield excavation routes of several tunnels, on the side close to the shield receiving shaft, and on the seaward side of the shield excavation routes of several tunnels.

[0016] Furthermore, a method for using the shield receiving shaft end reinforcement structure under the above-mentioned restricted conditions is characterized by comprising the following steps: During the process of tunnel excavation by the shield machine, when the cutter head is about to contact the outermost arched jet grouting pile, the ring hoop grouting is carried out at the 5th ring segment behind the shield tail of the shield machine to complete the first ring hoop; when the shield tail of the shield machine is about to pass through the outermost arched jet grouting pile, the ring hoop grouting is carried out at the 5th ring segment behind the shield tail to complete the second ring hoop; when the shield tail of the shield machine is about to be dragged out of the shield receiving well, the ring hoop grouting is carried out at the 4th ring segment behind the shield tail to complete the third ring hoop, so as to smoothly enter the shield receiving well.

[0017] The beneficial effects of the present invention are: The present invention utilizes the arrangement of arched jet grouting piles to disperse the thrust of the shield machine, and uses the bottom jet grouting piles as supports to reinforce the connection strength between the arched jet grouting piles and the ground-connected wall of the shield receiving shaft. The special structure of the arched jet grouting piles and the combination of the bottom jet grouting piles can effectively ensure the reinforcement effect. At the same time, under restricted conditions, it can reasonably avoid contact or interference with constraints by occupying a smaller area.

[0018] The present invention avoids the problem of traditional rectangular jet grouting pile structures that require increasing the width of rectangular jet grouting piles to ensure the reinforcement effect. The reinforcement strength can be adjusted as needed by adjusting the number of rows or the arc of the arched jet grouting piles, thereby achieving a multi-faceted adjustment to ensure the reinforcement effect. This solution effectively solves the problem of shield receiving shaft end reinforcement under restricted conditions, achieves safe shield reception, saves end reinforcement costs, shortens construction period, and has the characteristics of simple construction, flexible and convenient use, etc. It is suitable for shield receiving end reinforcement with complex surrounding environment and limited site.

[0019] The present invention constructs an arched high-pressure rotary jet pile reinforcement area outside the shield receiving shaft, which solves the problem that there are pressure lines of various angles on the top of the reinforcement area at the end of the shield receiving shaft, or water pipes of various angles are buried underground, which makes it impossible to carry out conventional reinforcement construction, thereby affecting the conditions for shield reception. By adopting this reinforcement structure, the interference caused by the influencing factors can be overcome through the effects of multi-faceted adjustment and reduced floor space, and the safety of the reinforcement area at the receiving end of the shield and the stability of the foundation pit of the receiving shaft are guaranteed, thereby ensuring the smooth reception of the shield. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of a top view of a shield receiving shaft end reinforcement structure under restricted conditions proposed by the present invention; Figure 2 A top view of a partial structure of a shield receiving shaft end reinforcement structure under restricted conditions proposed by the present invention; Figure 3 A structural side cross-sectional view of a shield receiving shaft end reinforcement structure under restricted conditions proposed by the present invention; Figure 4 A schematic plan view of the first hoop construction of a method for using a shield receiving shaft end reinforcement structure under restricted conditions proposed by the present invention; Figure 5 A schematic plan view of the second hoop construction of a method for using a shield receiving shaft end reinforcement structure under restricted conditions proposed by the present invention; Figure 6 A schematic plan view of the third hoop construction of a method for using a shield receiving shaft end reinforcement structure under restricted conditions proposed by the present invention; Figure 7 This is a schematic diagram of the reinforcement of the receiving shaft end of a conventional shield machine; Figure 8 Schematic diagram of obstacles in the reinforcement area at the end of the shield receiving shaft.

[0021] Figure numerals: 1. Shield receiving shaft; 2. Ground-connected wall; 3. Side wall of receiving shaft structure; 4. Arched jet grouting piles; 5. Straight jet grouting piles; 6. Bottom jet grouting piles; 7. Dewatering well; 8. Shield excavation route; 9. Segment; 10. Shield machine; 11. First hoop; 12. Second hoop; 13. Third hoop; 14. Rectangular jet grouting piles; 15. High-voltage line; 16. Water pipe. DETAILED DESCRIPTION

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] As attached Figure 1 , Attachment Figure 2 and attached Figure 3 As shown, a shield receiving shaft end reinforcement structure under restricted conditions of an embodiment of the present invention includes several rows of arched rotary jet piles 4 and bottom rotary jet piles 6. The outer wall to be reinforced of the ground-connected wall 2 of the shield receiving shaft 1 is provided with several rows of mutually interlocking or overlapping arched rotary jet piles 4 from near to far. Each row of arched rotary jet piles 4 includes several vertically arranged and mutually interlocking or overlapping rotary jet piles. Several rotary jet piles of the arched rotary jet piles 4 are arranged in an arch shape, and the arched opening faces the wall to be reinforced. The arched ends of the several rows of arched rotary jet piles 4 are all connected to the wall to be reinforced. The bottom between the arched rotary jet piles 4 closest to the wall to be reinforced and the wall to be reinforced is filled with bottom rotary jet piles 6 composed of several mutually interlocking or overlapping rotary jet piles. The bottom rotary jet piles 6 are respectively connected to the arched rotary jet piles 4 closest to the wall to be reinforced and the wall to be reinforced. The top of the bottom rotary jet piles 6 can be passed by a shield machine 10.

[0024] The present invention utilizes the arrangement of the arched jet grouting piles 4 to disperse the thrust of the shield machine 10. By arranging the bottom jet grouting piles 6 as support, the connection strength between the arched jet grouting piles 4 and the ground-connected wall 2 of the shield receiving shaft 1 can be reinforced. The special structure of the arched jet grouting piles 4 and the combination of the bottom jet grouting piles 6 can effectively ensure the reinforcement effect. At the same time, under restricted conditions, it can reasonably avoid contact or interference with constraints by occupying a smaller area.

[0025] The present invention avoids the problem of the traditional rectangular jet grouting pile 14 structure that the width of the rectangular jet grouting pile 14 must be increased to ensure the reinforcement effect. The reinforcement strength can be adjusted as needed by adjusting the number of rows or the arc of the arched jet grouting pile 4, thereby achieving a multi-faceted adjustment to ensure the reinforcement effect. This solution effectively solves the problem of the end reinforcement of the shield receiving shaft 1 under restricted conditions, realizes the safe reception of the shield, and saves the end reinforcement cost and shortens the construction period. It has the characteristics of simple construction, flexible and convenient use, and is suitable for the reinforcement of the shield receiving end with complex surrounding environment and limited site.

[0026] The present invention constructs an arched high-pressure rotary jet pile reinforcement area outside the shield receiving shaft 1, which can solve the problem that there are 500KV high-voltage lines at various angles on the top of the reinforcement area at the end of the shield receiving shaft 1, or DN500 tap water pipes at various angles buried underground make conventional reinforcement methods impossible to construct routinely, thereby affecting the conditions for shield reception. By adopting this reinforcement structure, the interference caused by the influencing factors can be overcome through the effects of multi-faceted adjustment and reduced floor space, and the safety of the reinforcement area at the shield receiving end and the stability of the receiving shaft foundation pit are guaranteed, thereby ensuring the smooth reception of the shield.

[0027] In another specific embodiment, it also includes straight-row jet grouting piles 5, and the outer wall to be reinforced of the ground-connected wall 2 of the shield receiving shaft 1 is provided with straight-row jet grouting piles 5 in a manner that is mutually fitted, interlocked or overlapped. The straight-row jet grouting piles 5 include several jet grouting piles that are vertically arranged and mutually interlocked or overlapped. Several jet grouting piles of the straight-row jet grouting piles 5 are mutually fitted, interlocked or overlapped with the wall to be reinforced, and are arranged in parallel with the wall to be reinforced. The ends of several rows of arched jet grouting piles 4 are connected to the wall through the straight-row jet grouting piles 5, and the bottom jet grouting piles 6 are connected to the straight-row jet grouting piles 5 on one side of the wall to be reinforced. In this way, the connection between the arched jet grouting piles 4 and the bottom jet grouting piles 6 and the outer wall to be reinforced of the ground-connected wall 2 of the shield receiving shaft 1 can be reinforced through the straight-row jet grouting piles 5, thereby increasing the strength of the structure and further ensuring the safety and stability of the reinforced area.

[0028] In another specific embodiment, the upper ends of several jet grouting piles of the bottom jet grouting piles 6 are flush with each other. The same specification of jet grouting piles are used for construction, which can improve the construction efficiency while ensuring the reinforcement strength of the reinforcement area.

[0029] In another specific embodiment, the bottom jet grouting pile 6 is composed of several jet grouting piles of different heights, and the upper end of the bottom jet grouting pile 6 is an arc groove consistent with the curvature of the outer side of the shield machine 10, the arc groove can be attached to the outer side of the shield machine 10 and coincide with the outer circle of the shield tunneling route 8, and the axial direction of the arc groove is consistent with the axial direction of the shield machine 10. In this way, the bottom jet grouting pile 6 structure with an arc groove at the upper end formed by the jet grouting piles of different heights can further enrich the support for the bottom structure without affecting the shield tunneling route 8 of the shield machine 10, further increase the reinforcement strength of the structure, and ensure the stability and safety of the structure.

[0030] In another specific embodiment, a dewatering well 7 is further included, and the dewatering well 7 is arranged between the shield excavation routes 8 of several tunnels, and is arranged on the side close to the shield receiving well 1. In this way, dewatering can be carried out as needed according to the groundwater level during the excavation process through the arrangement of the dewatering well 7. Among them, the dewatering well 7 is also arranged on the most seaward side of the shield excavation routes 8 of several tunnels. In this way, the fluid is easily dredged.

[0031] A construction method of a shield receiving shaft end reinforcement structure under the above-mentioned restricted conditions of the present invention comprises the following steps: At the wall to be reinforced outside the ground-connected wall 2 of the shield receiving shaft 1, several rotary jet piles are arranged according to preset dimensions to form a bottom rotary jet pile 6. The side of the bottom rotary jet pile 6 away from the wall to be reinforced is arc-shaped. Several rows of mutually interlocking or overlapping arched rotary jet piles 4 are arranged in sequence from near to far on one side of the arc of the bottom rotary jet pile 6. Both ends of the rows of arched rotary jet piles 4 are connected to the wall to be reinforced. A spacing is reserved between the top of the bottom rotary jet pile 6 and the top of the arched rotary jet pile 4 for the shield machine 10 to pass through, that is, the spacing reserved between the top of the bottom rotary jet pile 6 and the top of the arched rotary jet pile 4 is not less than the diameter of the shield machine 10.

[0032] In this embodiment, the arched jet grouting piles 4 can be arranged in four rows as required.

[0033] Among them, it also includes setting several rotary jet piles according to preset sizes to form a bottom rotary jet pile 6, and setting several mutually interlocking or overlapping rotary jet piles between the side of the bottom rotary jet pile 6 close to the wall to be reinforced and the wall to be reinforced to form a straight row of rotary jet piles 5 that are respectively interlocked or overlapped with the bottom rotary jet pile 6 and the wall to be reinforced, and both ends of the several rows of arched rotary jet piles 4 are interlocked or overlapped with the straight row of rotary jet piles 5.

[0034] Among them, the bottom rotary jet pile 6 is arranged by setting up several rotary jet piles of different heights, and the upper end of the bottom rotary jet pile 6 is an arc groove structure consistent with the outer curvature of the shield machine 10, and the axial direction of the arc groove structure is consistent with the axial direction of the shield machine 10.

[0035] Among them, dewatering wells 7 are respectively set between the shield excavation routes 8 of several tunnels, on the side close to the shield receiving shaft 1, and on the seaward side of the shield excavation routes 8 of several tunnels.

[0036] As attached Figure 4 , Attachment Figure 5 and attached Figure 6 As shown, a method for using the shield receiving shaft end reinforcement structure under the above-mentioned restricted conditions of the present invention comprises the following steps: During the tunnel excavation process of the shield machine 10, when the cutter head is about to contact the outermost arched jet grouting pile 4, the ring hoop grouting is applied to the 5th ring segment 9 behind the shield tail of the shield machine 10 at this time. The ring hoop grouting is carried out through the segment 9 hoisting hole using the existing grouting equipment on the shield machine 10, and a double liquid slurry of cement slurry and water glass is used to complete the first ring hoop 11; when the shield tail of the shield machine 10 is about to pass through the outermost arched jet grouting pile 4, the ring hoop grouting is applied to the 5th ring segment 9 behind the shield tail at this time to complete the second ring hoop 12; when the shield tail of the shield machine 10 is about to be dragged out of the shield receiving well 1 or the above-mentioned straight jet grouting pile 5, the ring hoop grouting is applied to the 4th ring segment 9 behind the shield tail at this time to complete the third ring hoop 13, so as to smoothly enter the shield receiving well 1. During the excavation process, precipitation is carried out as needed through the precipitation well 7 according to the groundwater level.

[0037] A specific implementation of the present invention is as follows: Two tunnels are set up, and two groups of four rows of mutually interlocking or overlapping arched jet piles 4 are set at the outer wall to be reinforced of the ground-connected wall 2 of the shield receiving shaft 1 in the form of high-pressure jet pile reinforcement. The jet pile diameter of the arched jet pile 4 is 850@500, the cement content is 30%, the reinforcement width is 2m on each side of the outer contour line of the tunnel, the longitudinal reinforcement length of the tunnel is 4m, the reinforcement range height is from 4m at the top of the tunnel to 3m at the bottom of the tunnel, the four rows of arched jet piles are 14.7m long, the jet piles at the bottom of the tunnel on the inner side of the arch are 3m long, the two end reinforcements are 102 each, and a row of straight jet piles 5 are added for reinforcement. The straight jet piles 5 overlap with the reinforced area on the outer side of the ground-connected wall 2 of the shield receiving shaft 1.

[0038] The hoop grouting is carried out through the hanging hole of the pipe segment 9 using the existing grouting equipment on the shield machine 10, using double liquid slurry of cement slurry and water glass. Three hoop groutings are set for each tunnel. The first hoop 11 is applied to the 5th ring segment 9 behind the shield tail when the cutterhead is about to contact the reinforcement area; the second hoop 12 is applied to the 5th ring segment 9 behind the shield tail when the shield tail is about to pass through the reinforcement area; the third hoop 13 is applied to the 4th ring segment 9 behind the shield tail when the shield tail is about to be dragged out of the tunnel.

[0039] The dewatering well 7 uses a steel pipe with a borehole diameter of 1000mm, a well pipe of φ600 and a wall thickness of 6mm for drainage and dewatering. The well bottom elevation is 7m from the bottom of the tunnel and the well depth is about 27.8m. At least one dewatering well 7 is set in the middle of the two tunnels close to the receiving well and at least one is set on the sea side. Then, dewatering is carried out according to the groundwater level during the excavation process.

[0040] The specific measures adopted in this plan also include: The reinforcement method must be carried out when the soil quality of the stratum is good. The high-pressure rotary jet piles used in the reinforcement method must ensure good pile-forming effects, and their pile lengths and diameters must meet the requirements of the plan. The area of ​​the arched high-pressure rotary jet piles used in the reinforcement method must overlap with the area reinforced on the outside of the ground-connected wall of the receiving well support structure to achieve the purpose of enhancing the reinforcement effect. The hoops used in the reinforcement method must be grouted in a timely and accurate manner as required, and the specific gravity and grouting pressure of the slurry must meet the requirements of the plan. The dewatering wells used in the reinforcement method must be observed more closely when the shield machine excavates to the area, and dewatering must be carried out in a timely manner. If the dewatering requirements are not met, the number of dewatering wells must be increased.

[0041] The present invention solves the problem of limited construction area conditions while satisfying the reinforcement effect of the shield receiving end. The shield receiving well end is reinforced by arched high-pressure jet grouting piles. The jet grouting piles are reinforced by outer arched jet grouting piles 4 and inner bottom jet grouting piles 6. The outer side is reinforced by four rows of arched jet grouting piles 4 as a whole. The inner side of the arch is reinforced by bottom jet grouting piles 6. Hoop grouting is performed in the hole. The external ground is assisted by dewatering wells 7 for dewatering. This effectively solves the problem of shield receiving well end reinforcement under restricted conditions, realizes safe reception of the shield, saves end reinforcement costs, shortens construction period, and has the characteristics of simple construction, flexible and convenient use, etc. It is suitable for reinforcement of shield receiving ends with complex surrounding environments and limited sites.

[0042] The scheme of the present invention mainly utilizes the arch to disperse the thrust of the shield machine, and fills the gap between the pipe segment 9 and the surrounding soil by constructing a hoop inside the tunnel, strengthens the support and blocks the water flow channel of the backing to prevent groundwater from flowing into the heading face, and then supplemented by drainage and precipitation methods, thereby ensuring the stability of the surrounding soil when the shield breaks the tunnel door.

[0043] It should be noted that the terms such as "upper", "lower", "left", "right", "front", "back", etc. cited in the invention are only for the convenience of description and are not used to limit the scope of implementation of the present invention. Changes or adjustments in their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0044] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A shield receiving shaft end reinforcement structure under restricted conditions, characterized in that: The invention comprises several rows of arched rotary jet piles (4) and bottom rotary jet piles (6). The outer wall to be reinforced of the ground-connected wall (2) of the shield receiving shaft (1) is provided with several rows of mutually interlocking or overlapping arched rotary jet piles (4) in sequence from near to far. Each row of the arched rotary jet piles (4) comprises several mutually interlocking or overlapping rotary jet piles arranged vertically. Several rotary jet piles of the arched rotary jet piles (4) are arranged in an arch shape. The opening of the arch faces the wall to be reinforced. The arched ends of the rows of arched rotary jet piles (4) are connected to the wall to be reinforced. The bottom between the arched rotary jet pile (4) closest to the wall to be reinforced and the wall to be reinforced is filled with a bottom rotary jet pile (6) composed of several mutually interlocking or overlapping rotary jet piles. The shield machine (10) can pass through the top of the bottom rotary jet pile (6).

2. The shield receiving shaft end reinforcement structure under restricted conditions according to claim 1, characterized in that: It also comprises straight row jet grouting piles (5), the straight row jet grouting piles (5) are arranged on the outer side of the ground-connected wall (2) of the shield receiving shaft (1) so as to interlock or overlap with the wall to be reinforced, the straight row jet grouting piles (5) comprise a plurality of jet grouting piles arranged vertically and interlocking or overlapping with each other, the plurality of jet grouting piles of the straight row jet grouting piles (5) are interlocked or overlapped with the wall to be reinforced, the ends of the plurality of rows of arched jet grouting piles (4) are connected to the wall through the straight row jet grouting piles (5), and the bottom jet grouting piles (6) are connected to the straight row jet grouting piles (5) on one side close to the wall to be reinforced.

3. The shield receiving shaft end reinforcement structure under restricted conditions according to claim 1, characterized in that: The upper ends of several rotary jet piles (6) at the bottom are flush with each other.

4. The shield receiving shaft end reinforcement structure under restricted conditions according to claim 1, characterized in that: The bottom jet grouting pile (6) is composed of a plurality of jet grouting piles of different heights, and the upper end of the bottom jet grouting pile (6) is an arc-shaped groove having the same arc as the outer curvature of the shield machine (10), and the axial direction of the arc-shaped groove is consistent with the axial direction of the shield machine (10).

5. The shield receiving shaft end reinforcement structure under restricted conditions according to claim 1, characterized in that: It also includes a dewatering well (7), wherein the dewatering well (7) is arranged between the shield excavation routes (8) of several tunnels and is arranged on a side close to the shield receiving well (1).

6. The shield receiving shaft end reinforcement structure under restricted conditions according to claim 5, characterized in that: The dewatering well (7) is also arranged on the seaward side of the shield tunneling routes (8) of the several tunnels.

7. A method for constructing a shield receiving shaft end reinforcement structure under restricted conditions as described in any one of claims 1 to 6, characterized in that: The steps include: At the wall to be reinforced outside the ground-connected wall (2) of the shield receiving shaft (1), a plurality of jet grouting piles are arranged according to a preset size to form a bottom jet grouting pile (6), the side of the bottom jet grouting pile (6) away from the wall to be reinforced is arc-shaped, and a plurality of rows of mutually interlocking or overlapping arched jet grouting piles (4) are arranged in sequence from near to far on the arc-shaped side of the bottom jet grouting pile (6), both ends of the rows of arched jet grouting piles (4) are connected to the wall to be reinforced, and a spacing is reserved between the top of the bottom jet grouting pile (6) and the top of the arched jet grouting pile (4) for a shield machine (10) to pass through.

8. The construction method of the shield receiving shaft end reinforcement structure under restricted conditions according to claim 7 is characterized in that: The method further comprises the following steps: arranging a plurality of jet grouting piles according to a preset size to form a bottom jet grouting pile (6); arranging a plurality of mutually interlocking or overlapping jet grouting piles between a side of the bottom jet grouting pile (6) close to the wall to be reinforced and the wall to be reinforced to form a straight row of jet grouting piles (5) respectively interlocking or overlapping with the bottom jet grouting pile (6) and the wall to be reinforced; and both ends of the plurality of rows of arched jet grouting piles (4) are mutually interlocked or overlapped with the straight row of jet grouting piles (5).

9. The construction method of the shield receiving shaft end reinforcement structure under restricted conditions according to claim 7, characterized in that: Drainage wells (7) are respectively arranged between the shield excavation routes (8) of the several tunnels, on the side close to the shield receiving shaft (1), and on the seaward side of the shield excavation routes (8) of the several tunnels.

10. A method for using the shield receiving shaft end reinforcement structure under restricted conditions as described in any one of claims 1 to 6, characterized in that: The steps include: During the tunnel excavation process of the shield machine (10), when the cutterhead is about to contact the outermost arched jet grouting pile (4), the ring hoop grouting is performed at the fifth ring segment (9) behind the shield tail of the shield machine (10) to complete the first ring hoop (11); when the shield tail of the shield machine (10) is about to pass through the outermost arched jet grouting pile (4), the ring hoop grouting is performed at the fifth ring segment (9) behind the shield tail to complete the second ring hoop (12); when the shield tail of the shield machine (10) is about to be dragged out of the shield receiving shaft (1), the ring hoop grouting is performed at the fourth ring segment (9) behind the shield tail to complete the third ring hoop (13) so as to smoothly enter the shield receiving shaft (1).

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