Shield underwater butt joint asymmetric olive-shaped freezing curtain reinforcing and water stopping structure

Abstract

The utility model relates to the technical field of shield tunnel construction, and discloses a shield underwater butt joint asymmetric olive-shaped freezing curtain reinforcing water stop structure which comprises a reinforcing body formed by freezing double rows of freezing pipes of a head of a preceding shield tunneling machine and a single row of freezing pipes of a head of a following shield tunneling machine in an asymmetric arrangement mode. The following shield tunneling machine stops tunneling when tunneling is within the range of 0.5-0.7 m outside the cutter head of the preceding shield tunneling machine; according to the freezing pipes, two rows of freezing pipes are arranged at the position of an inner machine head of a preceding shield tunneling machine, a single row of freezing pipes are arranged at the position of an inner machine head of a following shield tunneling machine, the ends of the two shield tunneling machines are reinforced through a freezing method to form an asymmetric olive-shaped reinforcing water stop structure, and under the protection of the reinforcing water stop structure, the two shield tunneling machines can conduct cutterhead replacement and underwater disassembly under normal pressure; by means of the reinforcing structure, shield seabed and river bottom underwater bidirectional tunneling safe butt joint can be achieved, the long-distance underwater tunnel construction efficiency is improved, and meanwhile the underwater tunnel construction risk is reduced.

Description

Technical Field

[0001] The utility model relates to an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for shield underwater docking, belonging to the technical field of shield tunneling construction. Background Technique

[0002] With the continuous advancement of China's urbanization construction process and the construction of a transportation power, for coastal and riverside cities such as Xiamen, Shanghai, Wuhan, Qingdao, etc., the construction of underwater tunnels such as under the sea and under the river will inevitably be faced. Except for the construction of underwater tunnels under urban lakes, methods such as building cofferdams, draining water, and open-cut can be used. Under rivers, seas, generally, the method of underground excavation (drill and blast method, TBM and shield method) and the immersed tube method are adopted. Because of its small environmental impact, no interference with existing traffic routes, high construction efficiency, wide application range, high safety, etc., the shield method has become the preferred method for underwater tunnel construction today.

[0003] In recent years, with the iteration of shield tunnel construction technology and the continuous emergence of new processes and new technologies, there are more and more planned cross-river and cross-sea tunnels. Compared with the traditional single shield tunneling method, the biggest advantage of the shield in-situ docking method is that there is no need to set up an intermediate access shaft, and the two shield machines tunneling towards each other effectively solve the problem of insufficient long-distance tunneling ability of the shield machine and greatly shorten the construction period. When carrying out long-distance shield construction under the sea and under the river with complex and changeable geological conditions, various problems such as wear of the shield cutter head and tool box will inevitably be encountered, and the instability of the excavation face in the extreme environment of ultra-high water pressure underwater will lead to serious engineering accidents. Therefore, the coupling of extreme conditions such as super-large diameter, ultra-high water pressure, and ultra-long distance makes the shield in-situ docking technology become a new trend in the construction of ultra-long distance undersea shield tunnels. When using the shield in-situ docking method of "tunneling towards each other, in-situ docking, discarding the shell and disassembling", ensuring the stability of the free face after shield docking and disassembly is the key to safe docking, and strict reinforcement measures must be taken in areas with poor rock self-stability to meet the requirements of water isolation and pressure isolation. Ordinary grouting reinforcement is difficult to accurately control the reinforcement range, while the freezing method, with its own characteristics of safety, reliability, controllability, wide application range, and no impact on shield docking and in-tunnel disassembly after thawing, can be used for the two-way docking reinforcement project of shield machines under various complex conditions.

[0004] As the construction of undersea and river-bottom tunnels enters a peak period, the simple and regular horizontal or vertical freezing in the layout form is difficult to meet the needs of the two-way docking project of undersea and river-bottom shields. For the need of two-way docking reinforcement of undersea and river-bottom shields under the action of seepage, relevant research on how to form a complete freezing and water-stop reinforcement plan to achieve the overall water-sealing curtain effect remains to be carried out, and it provides a basis for the important reference of the freezing design and construction of shield machines underwater in the future. Content of the Utility Model

[0005] The purpose of the present utility model is to overcome the above-mentioned deficiencies of the prior art and provide an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for shield underwater docking. By obliquely driving freezing pipes along the orifice of the shield shell of two bidirectional shield machines and extending them into the soil mass, and circulating refrigerant medium in the freezing pipes to transfer cold, after active freezing reaches the design standard, it is transferred to maintenance freezing. Finally, an integral olive-shaped frozen curtain water-stop reinforcement structure is formed at the ends of the two shield machines, achieving the disassembly and recovery of the bidirectional tunneling shield machine underwater under normal pressure conditions, saving construction period, improving resource utilization efficiency, having strong construction practicability, fine control of construction quality, and obvious water-sealing effect.

[0006] To achieve the above purpose, the present utility model adopts the following technical solutions:

[0007] An asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for shield underwater docking, including a plurality of freezing pipes, the freezing pipes respectively extend from the freezing holes of the two shield machine heads into the soil layer; the two shield machines tunnel bidirectionally successively, and the trailing shield machine stops tunneling when it reaches 0.5 m outside the cutter head of the leading shield machine; two rows of freezing pipes are arranged at the position of the inner cutter head of the trailing shield machine, and one row of freezing pipes is arranged at the position of the inner cutter head of the leading shield machine. The ends of the two shield machines are integrally reinforced to form an asymmetric "olive-shaped" closed water-isolating and pressure-isolating reinforcement structure. Under the protection of the frozen reinforcement structure, the two shield machines can replace the cutter head and disassemble underwater under normal pressure;

[0008] Preferably, the present utility model obliquely drives freezing pipes along the orifice of the shield shell of the bidirectional shield machine and extends them into the soil mass to form an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure by freezing.

[0009] Preferably, for the double-row freezing pipes at the cutter head of the leading shield machine, a total of 60 freezing pipes are arranged in the first row, inclined outward by not less than 20°, and the end of the freezing pipe is 6.25 m away from the shield shell of the shield machine; a total of 72 freezing pipes are arranged in the second row, inclined outward by not less than 30°, and the end of the freezing pipe is 7.25 m away from the shield shell of the shield machine.

[0010] Preferably, the second row of freezing pipes is horizontally staggered by 0.5 m and vertically staggered by 1 m from the first row of freezing pipes. For the single-row freezing pipes at the cutter head of the trailing shield machine, a row of 72 freezing pipes is arranged, inclined outward by not less than 15°, and the end of the freezing pipe is 5.25 m away from the shield shell of the shield machine.

[0011] Preferably, the distribution diameter of the double-row freezing pipes at the cutter head of the leading shield machine should be larger than that of the single-row freezing pipes at the cutter head of the trailing shield machine. The areas of the cutter heads of the two shield machines are frozen and reinforced to form an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure.

[0012] Preferably, the asymmetric olive-shaped frozen curtain reinforcement and water-stop structure should ensure that the maximum diameter of the reinforced body is larger than the diameter of the shield machine cutter head by 6.5 m - 7 m, and the transverse length of the reinforced body is not less than 8 m.

[0013] Preferably, the thickness of the frozen curtain in the weak area of the solid addition (the area around the gap between the two shield cutterheads) is not less than 3 m.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] Compared with the traditional vertical or horizontal freezing reinforcement at the ends of shield tunnels, the present utility model greatly reduces the consumption of freezing pipes, and also greatly reduces the cooling capacity required when the freezing construction meets the design requirements. The control effect of frost heaving and thaw settlement is obvious. While ensuring the reinforcement and water-stop effects, the integrity of the frozen curtain formed between the two shield machine heads is also good, with good energy utilization efficiency and great popularization and application value.

[0016] The present utility model relates to an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for underwater docking of shield machines, which is a new reinforcement design scheme for the disassembly and recycling after underwater docking of shield machines. The utility model is applicable to the reinforcement and water-stop of strata under high water pressure conditions such as the seabed and river bottom, can effectively solve the problem of relatively high risk coefficient of conventional reinforcement methods in related working conditions, and greatly improves the scientificity and advancement of the application of artificial freezing technology in the construction of underwater tunnels, and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to illustrate the embodiments of the present utility model or the prior art more specifically and intuitively, the following will briefly introduce the drawings required in the description of the embodiments or the prior art.

[0018] Figure 1 It is a longitudinal sectional view of the freezing pipe layout of an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for underwater docking of shield machines provided by the specific embodiment;

[0019] Figure 2 It is a sectional view of the formed curtain of an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for underwater docking of shield machines provided by the specific embodiment;

[0020] Figure 3 It is a cross-sectional view of the layout of the first row of freezing pipes of the leading shield machine of an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for underwater docking of shield machines provided by the specific embodiment;

[0021] Figure 4 It is a cross-sectional view of the layout of the second row of freezing pipes of the leading shield machine of an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for underwater docking of shield machines provided by the specific embodiment;

[0022] Figure 5 It is a cross-sectional view of the layout of a single row of freezing pipes of the trailing shield machine of an asymmetric olive-shaped frozen curtain reinforcement and water-stop structure for underwater docking of shield machines provided by the specific embodiment.

[0023] In the figure: 1 - leading shield machine, 2 - trailing shield machine, 3 - double - row freezing pipes, 4 - single - row freezing pipes, 5 - "olive - shaped" frozen curtain reinforcement and water - stop structure, 6 - cutter head. Specific implementation manners

[0024] The present utility model will be further described below in conjunction with the attached drawings and embodiments.

[0025] The structures, ratios, sizes, etc. drawn in the attached drawings of this specification are only used to cooperate with the content disclosed in the specification for those familiar with the relevant technologies to understand and read, and are not used to limit the limiting conditions under which the present utility model can be implemented. Therefore, they do not have technical essential significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present utility model can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear narration and are not used to limit the scope under which the present utility model can be implemented. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope under which the present utility model can be implemented.

[0026] Referring to the attached Figure 1 , 2 , 3, 4, 5, a shield underwater docking asymmetric olive - shaped frozen curtain reinforcement and water - stop structure, including a reinforced body formed by the asymmetric arrangement of double - row freezing pipes at the leading shield machine head and single - row freezing pipes at the trailing shield machine head; the freezing pipes respectively extend from the preset freezing holes at the leading shield machine and the trailing shield machine heads into the soil layer to form an asymmetric "olive - shaped" frozen curtain reinforcement and water - stop structure; the two shield machines tunnel in two - way succession, and the trailing shield machine stops tunneling within the range of 0.5 m - 0.7 m outside the cutter head of the leading shield machine. For the double - row freezing pipes at the leading shield machine head, a total of 60 are arranged in the first row, the outer - expansion inclination angle is not less than 20°, and the end of the freezing pipe is 6.25 m away from the shield shell of the shield machine; a total of 72 are arranged in the second row, the outer - expansion inclination angle is not less than 30°, and the end of the freezing pipe is 7.25 m away from the shield shell of the shield machine; the second - row freezing pipes are staggered 0.5 m horizontally and 1 m vertically from the first - row freezing pipes. For the single - row freezing pipes at the trailing shield machine head, a row of 72 freezing pipes are arranged, the outer - expansion inclination angle is not less than 15°, and the end of the freezing pipe is 5.25 m away from the shield shell of the shield machine. The distribution diameter of the double - row freezing pipes at the leading shield machine head should be larger than that of the single - row freezing pipes at the trailing shield machine head, freezing and reinforcing the areas of the two shield machine heads, and finally forming an asymmetric olive - shaped frozen curtain reinforcement and water - stop structure. The reinforcement and water - stop structure should ensure that the maximum diameter of the reinforced body is larger than the cutter head diameter of the shield machine by 6.5 m - 7 m, the transverse length of the reinforced body is not less than 8 m, and the thickness of the frozen curtain at the weak part (the area around the gap between the two shield cutters) of the reinforced body is not less than 3 m.

[0027] In this implementation plan, the excavation diameter of the underwater shield tunnel is about 16 m, and the perimeter is 50 m. The freezing pipes are arranged in a circular shape along the heads of the two shield machines, the leading one and the trailing one.

[0028] In this implementation plan, two rows of freezing pipes are arranged along the position of the head inside the leading shield machine. The first row of freezing pipes consists of 60 pipes numbered XD1 - XD60, with an outward expansion inclination angle of 21.7°, the minimum distance from the end to the shield shell of the shield machine is 6.25 m, and the length of the freezing pipe is 14.409 m.

[0029] In this implementation plan, the second row of freezing pipes consists of 72 pipes numbered XC1 - XC72, with an outward expansion inclination angle of 31.8°, the minimum distance from the end to the shield shell of the shield machine is 7.55 m, and the length of the freezing pipe is 16.386 m.

[0030] In this implementation plan, a single row of freezing pipes is arranged along the position of the head inside the trailing shield machine. The first row of freezing pipes consists of 72 pipes numbered HD1 - HD72, with an outward expansion inclination angle of 17.5°, the minimum distance from the end to the shield shell of the shield machine is 5.7 m, and the length of the freezing pipe is 9.262 m.

[0031] In this implementation plan, to understand the development of the temperature field at different times and determine the time for shield docking and opening the chamber for repair, in accordance with the design requirements, a circle of 8 temperature measurement holes is arranged in the tunnel on one side of the leading shield machine, and two circles of 14 + 8 temperature measurement holes are arranged inside and outside the tunnel on one side of the trailing shield machine.

[0032] In this implementation plan, a temperature measurement point is arranged at the interface between the frozen soil and the shield shell in each temperature measurement hole, and then a temperature measurement point is arranged every 1 - 1.5 m.

[0033] In this implementation plan, the temperature measurement points in the outer row of temperature measurement holes of the leading shield machine are numbered successively as HAi - 1, HAi - 2, HAi - 3, HAi - 4......(i = 1, 2, 3,......, 8), the temperature measurement points in the inner row of temperature measurement holes of the leading shield machine are numbered successively as HEi - 1, HEi - 2, HEi - 3, HEi - 4......(i = 1, 2, 3,......, 14), and the temperature measurement points of the trailing shield machine are numbered successively as XAi - 1, XAi - 2, XAi - 3, XAi - 4......(i = 1, 2, 3,......, 8), where i represents the number of the corresponding temperature measurement hole; mainly to measure the temperature development of different parts within the range of the frozen curtain, so as to comprehensively judge whether the development of the frozen wall is normal, whether it meets the freezing design requirements, determine the time for shield docking and opening the chamber for repair, and ensure the safety of construction.

[0034] In this implementation scheme, the freezing pipe is made of Φ89×10mm high-quality low-carbon seamless steel pipe, which is driven into the soil from the designed inner and outer edges of the freezing wall at the designed soil penetration angle. When driving the freezing pipe, the deflection angle of the freezing pipe should be calibrated, and the depth of the freezing pipe into the soil should be strictly controlled. Since the freezing pipes are all preset, different shapes of openings can be set according to different external expansion inclinations. According to different inclination angles, the shape of the opening must meet the deflection angle requirements of the freezing pipe.

[0035] In this implementation scheme, the specific method of installing the freezing pipe is: an orifice pipe is installed on the shield machine shell, and a linear sealing pipe is connected through a ball valve, which has the function of sealing water and preventing blowout, and then the freezing pipe is used as a drill rod to directly drill and bury.

[0036] In this implementation plan, based on the measured data, it is determined whether the freezing is normal, the frozen soil development speed and development radius are estimated, the thickness of the freezing curtain is calculated, and the average temperature of the freezing curtain is obtained by the average freezing temperature of multiple rows of holes. If the thickness and average temperature of the freezing curtain at each layer and position meet the design requirements, the pipe segment can be opened for excavation after the pre-excavation node acceptance is qualified.

[0037] In this implementation plan, the active freezing time is: 60 days for the first shield tunneling and 70 days for the second shield tunneling; the maintenance freezing time is 150 days. The flow rate of a single freezing hole is 5-8m 3 / h. The frozen soil development speed is 22mm / d, the freezing curtain is completed in 18-22 days, and the time to reach the designed thickness is 45 days.

[0038] In this implementation scheme, during the maintenance freezing period, the temperature of the maintenance freezing period is in the range of -25°C to -28°C, and the freezing time runs through the shield machine dismantling construction period.

[0039] The above is only a more reasonable specific implementation method of the utility model, but the protection scope of the utility model is not limited to this. Any technician familiar with the technical field within the technical scope disclosed by the utility model, according to the technical scheme and utility model concept of the utility model, shall be covered by the protection scope of the utility model.

Claims

1. A shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure, characterized in that: The invention comprises a reinforced body formed by asymmetrically arranged freezing of double-row freezing pipes (3) at the head of a leading shield machine (1) and single-row freezing pipes (4) at the head of a trailing shield machine (2); the double-row freezing pipes (3) and single-row freezing pipes (4) are respectively extended from freezing holes arranged at the heads of the leading shield machine (1) and the trailing shield machine (2) into the soil layer, and are frozen to form a reinforced water-stopping structure (5); the two shield machines excavate in both directions successively, and the trailing shield machine (2) stops excavating when it excavates to within a range of 0.5m-0.7m outside the cutterhead (6) of the leading shield machine (1).

2. According to claim 1, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure is characterized in that: The leading shield machine (1) has double rows of freezing pipes (3) at the head, with the first row having 60 pipes in total, an outward expansion angle of inclination not less than 20°, and a minimum distance from the end of the freezing pipe to the shield shell of the shield machine of 6.25 m; the second row has 72 pipes in total, an outward expansion angle of inclination not less than 30°, and a minimum distance from the end of the freezing pipe to the shield shell of the shield machine of 7.25 m.

3. According to claim 2, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure is characterized in that: The second row of the double-row freezing pipes (3) is staggered with the first row by 0.5 m in the horizontal direction and by 1 m in the vertical direction.

4. According to claim 1, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure is characterized in that: The single-row freezing pipe (4) at the head of the rear shield machine (2) is arranged with a total of 72 freezing pipes in a row, with an outward expansion inclination angle of not less than 15°, and the minimum distance from the end of the freezing pipe to the shield shell of the shield machine is 5.25m.

5. According to claim 2, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure is characterized in that: The distribution diameter of the double-row freezing pipes (3) at the head of the leading shield machine (1) should be larger than that of the single-row freezing pipes (4) at the head of the trailing shield machine (2).

6. According to claim 1, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure is characterized in that: The double-row freezing pipes (3) and the single-row freezing pipes (4) freeze and reinforce the head areas of the two shield machines, forming an asymmetric olive-shaped freezing curtain reinforcement water-stopping structure (5).

7. According to claim 6, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure, characterized in that; The asymmetric olive-shaped freezing curtain reinforcement water-stopping structure (5) should ensure that the maximum diameter of the reinforcement body is greater than the diameter of the shield machine cutter head (6) by 6.5m-7m, and the horizontal length of the reinforcement body is not less than 8m.

8. According to claim 6, a shield underwater docking asymmetric olive-shaped freezing curtain reinforced water-stopping structure, characterized in that; The thickness of the freezing curtain of the reinforcement body located in the weak area between the two shield cutter heads is not less than 3m.

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