Pipe roofing structure method tunnel freezing sleeve and longitudinal segmented maintenance freezing structure and method

Abstract

The invention relates to the field of tunnel engineering, in particular to a pipe-roofing-structure-method tunnel freezing sleeve and a longitudinal segmented maintenance freezing structure and method. The invention provides a pipe-roofing-structure-method tunnel freezing sleeve and a pipe-roofing-structure-method tunnel longitudinal segmented maintenance freezing structure and method, the way that a freezing pipe is arranged on a liquid supply pipe in a sleeving mode is adopted to arrange an outlet path and a loop of the freezing sleeve, and partitioned supply of refrigerants is achieved by moving the length of the part, located in the freezing pipe, of the liquid supply pipe.

Description

Technical Field

[0001] The present invention relates to the field of tunnel engineering, and more specifically, to a tunnel freezing casing using a pipe-roof structure method, a longitudinal segmented maintenance freezing structure and a method. Background Art

[0002] The pipe curtain structure method is a common construction method in the field of tunnel construction. A longitudinally penetrating steel pipe is arranged on the tunnel contour, and then a continuous steel shell structure is formed by cutting the steel pipe and connecting the cuts of two adjacent steel pipes with steel plates. Internal steel components are set in the steel shell structure and concrete is poured, so as to form a continuous pre-support structure before tunnel excavation. When cutting the steel pipe, the stratum will be exposed, so it is necessary to reinforce and stop the stratum around the steel pipe in advance to ensure construction safety. When the pipe curtain structure method is used to dig a tunnel on a soft soil stratum, the ground freezing method is mainly used as an advance support measure. Before tunnel excavation, a pipe curtain steel pipe is set on the outside of the tunnel structure contour, and freezing pipes are set on the outside and inside of the steel pipe to freeze and reinforce the stratum between the pipe curtains and within the pipe curtain range; after the freezing curtain is formed, the tunnel contour surrounded by the pipe curtain is excavated, and the stratum is excavated and the support structure is constructed under the protection of the pipe curtain and the frozen soil curtain, and the tunnel construction is completed in a cycle. However, the existing ground freezing method has the following problems when applied to the construction of the pipe curtain structure method:

[0003] 1. The processes of cutting and welding steel pipes to expose the strata between pipes in the pipe-curtain structure tunnel can be constructed from the middle of the tunnel to both ends. This is different from the existing dark-cut tunnels that are constructed from both ends to the middle or from one end to the other. The construction direction of the stratum exposure process is different, which leads to different requirements for the sequence of stratum freezing and reinforcement.

[0004] 2. For the pipe-curtain structure tunnel, after the steel pipe welding and internal concrete pouring of a section are completed, it is no longer necessary to keep the frozen soil structure outside the pipe-curtain in this section frozen. For energy conservation, the frozen partitions should be able to change gradually with the construction sections in the pipe-curtain. However, in the existing methods, the longitudinal frozen partitions are fixed. Even if most of the internal concrete of the pipe-curtain in a partition has been poured, the partition still needs to remain frozen due to the limitation of the freezing pipe layout, which results in a long freezing time and waste of energy and investment.

[0005] Therefore, it is necessary to develop a maintenance freezing method suitable for the construction steps of the pipe-curtain structure method based on the characteristics of the structure and construction of the pipe-curtain structure method, which can reduce the supply of cold air and save energy while ensuring effective water stopping. Summary of the invention

[0006] The purpose of the present invention is to provide a freezing sleeve for a tunnel using a pipe curtain structure method, as well as a longitudinal segmented maintenance freezing structure and method for a tunnel using a pipe curtain structure method. The freezing sleeve is arranged by sleeved freezing pipes on liquid supply pipes to arrange the outgoing and returning paths of the freezing sleeves, and the zoned supply of refrigerant is achieved by moving the length of the liquid supply pipe located in the freezing pipe.

[0007] In order to achieve these purposes and other advantages according to the present invention, a tunnel freezing casing of a pipe-roof structure method is provided, comprising:

[0008] A freezing pipe, the open end of which is provided with an orifice device, the orifice device is provided with a refrigerant outlet, and the refrigerant outlet is connected to a loop pipe of an external freezing system;

[0009] A liquid supply pipe has one end extending into the freezing pipe and the other end connected to a removal pipe of an external freezing system. The liquid supply pipe is slidably connected to the orifice device to adjust the length of the portion extending into the freezing pipe.

[0010] The beneficial effects of the present invention are as follows: the sealed end of the freezing pipe extends into the freezing hole in the formation, the liquid supply pipe extends into the freezing pipe from the open end of the freezing pipe and is slidably connected through an orifice device, the refrigerant of the external freezing system enters the liquid supply pipe through the outlet pipe, and enters the freezing pipe from the opening at one end of the liquid supply pipe, most of the refrigerant entering the freezing pipe moves toward the refrigerant outlet and returns to the external freezing system through the loop pipe, and a very small amount of the refrigerant enters the area in the freezing pipe that is not covered by the liquid supply pipe, and the freezing effect of this area is poor. The main freezing area of ​​the freezing pipe is still the area covered by the liquid supply pipe in the freezing pipe. Therefore, during the sliding process of the liquid supply pipe in the freezing pipe, the circulation trajectory of the refrigerant in the freezing pipe changes with the change of the length of the part of the liquid supply pipe extending into the freezing pipe, thereby changing the main freezing area of ​​the freezing pipe. Then the construction of the pipe curtain structure tunnel can be carried out in sections from the inside to the outside. After the construction of the prefabricated lining structure of the inner part is completed and meets the load-bearing requirements, the stratum corresponding to this part of the prefabricated lining structure does not need to be frozen anymore, and the surrounding frozen body can be thawed. Therefore, the freezing pipe can be moved outward at this time, so that the refrigerant in the freezing pipe is mainly supplied to the stratum in some areas where the concrete pouring in the full ring pipe has not been completed, and the stratum in some areas where the prefabricated lining structure has been completed can be gradually thawed naturally. In summary, the length of the liquid supply pipe in the stratum, that is, the length of the part extending into the freezing pipe, can change with the progress of construction, the area where the prefabricated lining structure has been completed can be unfrozen for maintenance, and the area where the prefabricated lining structure has not been completed can continue to be effectively frozen, and the frozen area can be moved with the construction area, so that the cold energy is used in the area that needs freezing most, reducing energy waste.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows:

[0012] Further, in the tunnel freezing casing of the pipe-roof structure method, the orifice device comprises:

[0013] A sealing plate, which seals the open end of the freezing pipe, wherein the sealing plate is provided with a first opening and a second opening, and the second opening is the refrigerant outlet;

[0014] A connecting pipe is arranged on the sealing plate and communicated with the first opening. The liquid supply pipe passes through the connecting pipe and is slidably fitted therewith.

[0015] The beneficial effect of adopting the above further scheme is: in this further scheme, the open end of the freezing pipe is sealed by a sealing plate, the sealing plate can be integrally processed and formed with the freezing pipe, and the connecting pipe can be connected to the sealing plate by a fixed connection method such as welding.

[0016] Furthermore, in the freezing casing of the tunnel using the pipe-roof structure method, valves are provided on both the return pipe and the outgoing pipe.

[0017] The beneficial effect of adopting the above further scheme is: in this further scheme, by providing valves on the return pipe and the outgoing pipe, the flow rate of the refrigerant in the return pipe and the outgoing pipe is adjusted by the valves, so as to adjust the freezing effect of the freezing sleeve.

[0018] The present invention also provides application of the freezing sleeve in freezing reinforcement construction of a combined pipe-curtain tunnel.

[0019] The present invention also provides a freezing sleeve assembly for a pipe-roof structure tunnel, comprising two groups of the freezing sleeves mentioned above, the two groups of freezing sleeves being arranged opposite to each other, and the sealing ends of the freezing pipes being cross-lapped.

[0020] The beneficial effect of adopting the above-mentioned further scheme is: in this further scheme, when the pipe curtain construction of the pipe curtain structure tunnel is constructed from the middle to both ends, and the steel pipe cutting and welding process of the pipe curtain structure is constructed from the middle to both sides, the freezing hole in the stratum penetrates the stratum, and a group of freezing casings are respectively arranged at both ends of the freezing hole. The sealed ends of the freezing pipes are cross-lapped so that the freezing areas of the two groups of freezing casings can cover the entire freezing hole in the longitudinal direction. When the pipe curtain structure is constructed, the pipe curtain structure tunnel can be constructed in sections from the middle of the pipe curtain toward both ends from the inside to the outside. According to construction needs, the liquid supply pipes of the two groups of freezing casings are pulled out respectively.

[0021] The present invention also provides a longitudinal segmented maintenance freezing structure for a tunnel using a pipe-roof structure method, comprising a plurality of groups of the freezing casings mentioned above, wherein the freezing casings extend into the stratum outside the pipe-roof steel pipe.

[0022] The beneficial effect of adopting the above further scheme is: in this further scheme, when constructing a tunnel using the pipe-curtain structure method, a longitudinal segmented maintenance freezing structure is adopted, and the tunnel is divided into multiple sections along the longitudinal direction. The pre-built lining structure construction of each section is completed from the inside to the outside. At the same time, according to actual needs, the liquid supply pipes of the two groups of freezing casings are pulled outward respectively to reduce the freezing of part of the stratum where the pre-built lining structure has been completed, so that the cold energy is used in the areas that need freezing most, thereby reducing energy waste.

[0023] The present invention also provides a tunnel longitudinal segmentation maintenance freezing method using a pipe-roof structure method, which adopts the longitudinal segmentation maintenance freezing structure and comprises the following steps:

[0024] S1. Drill multiple freezing holes in the ground within the range of the pipe curtain steel pipe, respectively set the freezing sleeves in the freezing holes, and connect the freezing sleeves to the external freezing system, dividing the tunnel into multiple sections along the longitudinal direction. In the initial state, one end of the liquid supply pipe is located in the innermost section;

[0025] S2, continuously inputting refrigerant into each of the freezing casings through an external freezing system, so that a frozen body is formed in the formation around each of the freezing casings;

[0026] S3, after the strength of the frozen body reaches the design and construction requirements, the prefabricated lining structure of the innermost section is constructed, and after the strength of the prefabricated lining structure after construction reaches the bearing requirements, the liquid supply pipe is moved outward until one end of the opening is close to the next section;

[0027] S4, repeat S3, complete the construction of the prefabricated lining structure of each section in turn, until the construction of the pipe curtain in the tunnel is completed, and then pull out all the freezing casings.

[0028] The beneficial effect of adopting the above further scheme is that in this further scheme, the frozen liquid supply pipe can be moved along the longitudinal direction of the tunnel with the construction section, which can adapt to the construction sequence from the middle to the two ends of the pipe curtain structure method, and can be divided into any areas. The thawing sequence of the freezing method of the present invention is the same as the sequence of completion of the tunnel pre-built lining construction. The area where the pre-built lining has been completed is unfrozen for maintenance, and the area where the pre-built lining has not been completed continues to be effectively frozen, and the frozen area can move with the construction area, so that the cold energy is used in the area that needs freezing the most, reducing energy waste.

[0029] Furthermore, in the longitudinal segmented maintenance freezing method of the pipe-roof structure tunnel, when the prefabricated lining structure of the pipe-roof structure tunnel is constructed from the middle to both sides, the freezing hole in S1 penetrates the stratum, and the freezing casings are respectively arranged at both ends of the freezing hole, and the sealed ends of the two groups of the freezing casings are cross-lapped.

[0030] The beneficial effect of adopting the above further scheme is: in this further scheme, when the pipe curtain construction of the pipe curtain structure tunnel is constructed from the middle to both ends, the steel pipe cutting and welding process of the pipe curtain structure is constructed from the middle to both sides, the freezing hole in the stratum penetrates the stratum, and a set of freezing sleeves are respectively set at both ends of the freezing hole, so that the freezing area of ​​the two sets of freezing sleeves can cover the entire freezing hole in the longitudinal direction. Starting from the section where the pipe curtain construction starts, refer to the method of S3 to construct on both sides, and complete the prefabricated lining structure construction of each section in turn.

[0031] Furthermore, in the longitudinal segmented maintenance freezing method of the pipe-roof structure method tunnel, the prefabricated lining structure construction of the section includes the cutting and connection construction of the pipe-roof steel pipe, the internal structure of the pipe-roof steel pipe and the concrete construction.

[0032] The present invention also provides the use of any of the above-mentioned tunnel freezing sleeves of the pipe-roof structure method in the freezing reinforcement construction of a combined pipe-roof tunnel.

[0033] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the freezing casing of the tunnel using the pipe-roof structure method described in the present invention;

[0035] Figure 2 It is a cross-sectional schematic diagram of the freezing casing of the tunnel using the pipe-roof structure method according to the present invention;

[0036] Figure 3 It is a schematic diagram of the structure of the orifice device of the present invention;

[0037] Figure 4 It is a structural schematic diagram of the freezing casing assembly of the tunnel using the pipe-roof structure method described in the present invention;

[0038] Figure 5 It is a structural schematic diagram of the freezing sleeve in the longitudinal segmented maintenance freezing method of the tunnel using the pipe-roof structure method of the present invention;

[0039] Figure 6 It is a structural schematic diagram of a frozen reinforcement structure of a combined pipe-roof tunnel in an embodiment of the present invention;

[0040] Figure 7 It is a schematic structural diagram of the frozen reinforcement structure of the combined pipe-roof tunnel in an embodiment of the present invention.

[0041] Wherein, the reference numerals represent:

[0042] Freezing pipe 1; liquid supply pipe 2; freezing circle 3; weak cold junction area 3-1; strong cold junction area 3-2; combined weak cold junction area 3-3; combined strong cold junction area 3-4; return pipe 4; outgoing pipe 5; connecting pipe 6; valve 7; steel pipe group 8. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0044] It should be noted that, in the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0045] like Figure 1-Figure 2 As shown, an embodiment of the present invention provides a tunnel freezing casing using a pipe-roof structure method, comprising:

[0046] A freezing pipe 1, whose open end is provided with an orifice device, on which a refrigerant outlet is provided, and the refrigerant outlet is connected to a loop pipe 4 of an external freezing system;

[0047] One end of the liquid supply pipe 2 extends into the freezing pipe 1, and the other end is connected to the outlet pipe 5 of the external freezing system. The liquid supply pipe 2 is slidably connected to the orifice device to adjust the length of the portion extending into the freezing pipe 1.

[0048] In this embodiment, the sealed end of the freezing pipe 1 extends into the freezing hole in the formation, the liquid supply pipe 2 extends into the freezing pipe 1 from the open end of the freezing pipe 1, and is slidably connected through an orifice device, and the refrigerant of the external freezing system enters the liquid supply pipe 2 through the outlet pipe 5, and enters the freezing pipe 1 from the opening at one end of the liquid supply pipe 2. Most of the refrigerant entering the freezing pipe 1 moves toward the refrigerant outlet and returns to the external freezing system through the loop pipe 4. A very small amount of refrigerant will enter the area of ​​the freezing pipe 1 that is not covered by the liquid supply pipe 2. The freezing effect of this area is poor. The main freezing area of ​​the freezing pipe 1 is still the area covered by the liquid supply pipe 2 in the freezing pipe 1. Therefore, during the sliding process of the liquid supply pipe 2 in the freezing pipe 1, the circulation trajectory of the refrigerant in the freezing pipe 1 changes with the change of the length of the part of the liquid supply pipe 2 extending into the freezing pipe 1, thereby changing the main freezing area of ​​the freezing pipe 1.

[0049] Preferably, as another embodiment of the present invention, the orifice device comprises:

[0050] A sealing plate, which seals the open end of the freezing pipe 1, wherein the sealing plate is provided with a first opening and a second opening, and the second opening is the refrigerant outlet;

[0051] The connecting pipe 6 is arranged on the sealing plate and communicated with the first opening. The liquid supply pipe 2 passes through the connecting pipe 6 and is slidably fitted therewith.

[0052] In this embodiment, the opening end of the freezing pipe 1 is sealed by a sealing plate, the sealing plate can be integrally formed with the freezing pipe 1, and the connecting pipe 6 can be connected to the sealing plate by a fixed connection method such as welding.

[0053] Preferably, as another embodiment of the present invention, in the pipe-roof structure method tunnel freezing casing, valves 7 are provided on both the return pipe 4 and the outgoing pipe 5.

[0054] In this embodiment, valves 7 are provided on the return pipe 4 and the outgoing pipe 5, and the flow rates of the refrigerant in the return pipe 4 and the outgoing pipe 5 are adjusted by the valves 7, so as to adjust the freezing effect of the freezing sleeve.

[0055] like Figure 4 As shown, the present invention also provides a freezing sleeve assembly for a pipe-roof structure tunnel, comprising two groups of the above-mentioned freezing sleeves, the two groups of the freezing sleeves are arranged opposite to each other, and the sealed ends of the freezing pipes 1 are cross-lapped.

[0056] In this embodiment, when the pipe curtain construction of the pipe curtain structure tunnel is constructed from the middle to both ends, and the steel pipe cutting and welding process of the pipe curtain structure is constructed from the middle to both sides, the freezing hole in the stratum penetrates the stratum, and a group of freezing sleeves are respectively arranged at both ends of the freezing hole. The sealed ends of the freezing pipes 1 are cross-lapped so that the freezing areas of the two groups of freezing sleeves can cover the entire freezing hole in the longitudinal direction. When the pipe curtain structure is constructed, the pipe curtain structure tunnel can be constructed in sections from the middle of the pipe curtain toward both ends from the inside to the outside. According to construction needs, the liquid supply pipes 2 of the two groups of freezing sleeves are pulled out respectively.

[0057] The present invention also provides a longitudinal segmented maintenance freezing structure for a tunnel using a pipe-roof structure method, comprising a plurality of groups of the freezing casings mentioned above, wherein the freezing casings extend into the stratum outside the pipe-roof steel pipe.

[0058] In this embodiment, during the construction of the tunnel using the pipe-curtain structure method, a longitudinal segmented maintenance freezing structure is adopted, the tunnel is divided into multiple sections along the longitudinal direction, and the pre-built lining structure construction of each section is completed from the inside to the outside. At the same time, according to actual needs, the liquid supply pipes 2 of the two groups of freezing casings are pulled outward respectively to reduce the freezing of part of the stratum where the pre-built lining structure has been completed, so that the cold energy is used in the areas that need freezing the most, thereby reducing energy waste.

[0059] The present invention also provides a tunnel longitudinal segmentation maintenance freezing method using a pipe-roof structure method, which adopts the longitudinal segmentation maintenance freezing structure and comprises the following steps:

[0060] S1. Drill multiple freezing holes in the ground within the range of the pipe curtain steel pipe, respectively set the freezing casings in the freezing holes, and connect the freezing casings to the external freezing system, dividing the tunnel into multiple sections along the longitudinal direction. In the initial state, one end of the liquid supply pipe 2 is located in the innermost section;

[0061] S2, continuously inputting refrigerant into each of the freezing casings through an external freezing system, so that a frozen body is formed in the formation around each of the freezing casings;

[0062] S3, after the strength of the frozen body reaches the design and construction requirements, the prefabricated lining structure of the innermost section is constructed, and after the strength of the prefabricated lining structure after construction reaches the bearing requirements, the liquid supply pipe 2 is moved outward until one end of the opening is close to the next section;

[0063] like Figure 5 As shown in , firstly, the cutting and connection construction of the pipe curtain steel pipe is carried out in the L1 section. During this process, the refrigerant is continuously input to ensure that the frozen body around the steel pipe is complete and effective. After the cutting and connection of the L1 section steel pipe is completed, the internal structure of the steel pipe is constructed, the concrete in the pipe is poured, and then the cutting construction of the L2 section steel pipe is carried out. After the pre-built lining structure in the L1 section meets the load-bearing requirements, the surrounding frozen body can be thawed. At this time, the liquid supply pipe 2 can be pulled outward for a certain distance, so that one end of the liquid supply pipe 2 in the stratum moves toward the L2 section, so that the refrigerant is mainly supplied to the L2 section where the concrete pouring in the full ring pipe has not been completed. Since there is no continuous refrigerant supply in the L1 section, the stratum can gradually thaw naturally. The length and number of the construction sections can be arbitrarily set according to the construction needs. The length of the liquid supply pipe 2 in the stratum can change with the construction progress. The area where the pre-built lining structure has been completed is unfrozen for maintenance, and the area where the pre-built lining is not completed is continuously and effectively frozen. The frozen area can move with the construction area, so that the cold energy is used in the area that needs freezing most, reducing energy waste.

[0064] The prefabricated lining structure construction of the section includes the cutting and connection of the pipe curtain steel pipe, the internal structure of the pipe curtain steel pipe and the concrete construction;

[0065] S4, repeat S3, complete the construction of the prefabricated lining structure of each section in turn, until the construction of the pipe curtain in the tunnel is completed, and then pull out all the freezing casings.

[0066] Furthermore, in the longitudinal segmented maintenance freezing method of the pipe-roof structure tunnel, when the prefabricated lining structure of the pipe-roof structure tunnel is constructed from the middle to both sides, the freezing hole in S1 penetrates the stratum, and the freezing casings are respectively arranged at both ends of the freezing hole, and the sealed ends of the two groups of the freezing casings are cross-lapped.

[0067] In this embodiment, when the pipe curtain construction of the pipe curtain structure tunnel is constructed from the middle to both ends, the steel pipe cutting and welding process of the pipe curtain structure is constructed from the middle to both sides, the freezing hole in the stratum penetrates the stratum, and a set of freezing sleeves are respectively set at both ends of the freezing hole, so that the freezing areas of the two sets of freezing sleeves can cover the entire freezing hole in the longitudinal direction. Starting from the section where the pipe curtain construction starts, construction is performed on both sides respectively with reference to the method of S3, and the prefabricated lining structure construction of each section is completed in turn.

[0068] The embodiment of the present invention also provides the application of any of the above-mentioned pipe-roof structure tunnel freezing sleeves in the pipe-roof structure tunnel freezing reinforcement construction, specifically:

[0069] A freezing reinforcement structure of a combined pipe curtain tunnel includes a plurality of first freezing devices and a second freezing device, each of which includes a plurality of the above-mentioned freezing sleeves, and the distribution density of the plurality of freezing sleeves of the first freezing device in the freezing circle 3 is greater than the distribution density of the plurality of freezing sleeves of the second freezing device in the freezing circle 3. The portion of the freezing circle 3 located between adjacent steel pipe groups 8 is a strong cold junction area 3-2, in which the first freezing device is arranged, and the lateral width of the strong cold junction area 3-2 is greater than the lateral width of the area where the stratum is exposed when the steel pipe group 8 is cut, and the portions of the freezing circle 3 located on both sides of the strong cold junction area 3-2 are respectively weak cold junction areas 3-1, in which the second freezing device is arranged, and the temperature of the frozen body in the strong cold junction area 3-2 is lower than the temperature of the frozen body in the weak cold junction area 3-1.

[0070] like Figure 6As shown, between adjacent steel pipe groups 8 of the combined pipe curtain tunnel, the steel pipes 1 on both sides of the steel pipe group 8 are used as a combined pipe body, and a strong cold junction area 3-2 is arranged at the part where the combined pipe body needs to be cut. The outer lateral width Dq1 and the inner lateral width Dq2 of the strong cold junction area 3-2 need to be larger than the outer lateral width B1 and the inner lateral width B2 of the stratum range exposed when the steel pipe 1 is cut, so as to ensure that the stratum range exposed when the steel pipe 1 is cut is located in the strong cold junction area 3-2, and the freezing effect in the strong cold junction area 3-2 needs to meet the requirement of still ensuring the freezing performance after the heat loss caused by the construction. At the same time, weak cold junction areas 3-1 are set on both sides of each strong cold junction area 3-2. The purpose of setting the weak reinforcement area is to enable the frozen body to still play a role of sealing and stopping water under the influence of the strong heat source of cutting and welding of the steel pipe 1 and the ventilation in the steel pipe 1, so as to prevent groundwater from flowing into the steel pipe 1 along the contact surface between the strong reinforcement area and the steel pipe group 8. The outer lateral width Dr1 and the inner lateral width Dr2 of the weak cold junction area 3-1 should be determined according to the above-mentioned water-stopping requirements. The frozen body temperature in the weak cold junction area 3-1 is lower than the frozen body temperature in the strong cold junction area 3-2. The area between the adjacent weak cold junction areas 3-1 on the freezing circle 3 may not be frozen. Figure 4 This embodiment sets freezing reinforcement areas of different strengths on the tunnel section, which can meet the requirement that the steel pipe 1 and the steel pipe group 8 in the combined pipe curtain structure only need to cut the steel pipe 1 locally, perform local strong freezing, and weakly freeze or not freeze the remaining sections, so as to achieve the reinforcement and water-stopping effects while saving energy.

[0071] In addition, when two adjacent strong cold junction areas 3-2 overlap or the distance between them is smaller than the distance between two adjacent freezing sleeves 2 in the weak cold junction area 3-1, the two are combined or the area between them is replaced with the strong cold junction area 3-2 to form a combined strong cold junction area 3-4. Figure 7 In the embodiment, when the steel pipe group 8 has only one steel pipe 1, the distance between the openings on both sides of the steel pipe group 8 is relatively close, and the two strong cold junction areas 3-2 on both sides may overlap, or overlap with the weak freezing area between the two. At this time, the two strong cold junction areas 3-2 are merged into a large combined strong cold junction area 3-4, or the area between the two is set as a strong cold junction area 3-2 to form a combined strong cold junction area 3-4. The outer lateral width Dq3 and the inner lateral width Dq4 of the combined strong cold junction area 3-4 should be able to envelop the stratum ranges B1 and B2 exposed by adjacent cuts, and should be able to meet the requirement of ensuring freezing performance after heat loss caused by construction.

[0072] When two adjacent weak cold junction areas 3-1 overlap or the spacing is smaller than the spacing between two adjacent freezing sleeves 2 in the weak cold junction area 3-1, the two are merged or the area between the two is replaced with the weak cold junction area 3-1 to form a combined weak cold junction area 3-3. The outer lateral width of the combined weak cold junction area 3-3 is Dr3, and the inner lateral width is Dr4.

[0073] The freezing reinforcement method of the combined pipe-roof tunnel comprises the following steps:

[0074] S1, completing the jacking construction of the steel pipe group 8 of the combined pipe-curtain tunnel;

[0075] S2. The freezing circle 3 of the combined pipe-roof tunnel is divided into a plurality of freezing work areas connected end to end, and both ends of the freezing work area are weak cold junction areas 3-1, and independent freezing devices are used in the freezing work area, and each freezing work area is constructed independently.

[0076] Specific:

[0077] The area between adjacent steel pipe groups 8 on the freezing circle 3 of the combined pipe curtain tunnel is used as the strong cold junction area 3-2, and the areas on both sides of the freezing circle 3 of the combined pipe curtain tunnel are used as the weak cold junction area 3-1, and the installation of the freezing sleeves 2 in the cold junction area, the weak cold junction area 3-1 and the steel pipe group 8 is completed respectively, and the distribution density of the freezing sleeves 2 in the strong cold junction area 3-2 is greater than the distribution density of the freezing sleeves 2 in the weak cold junction area 3-1;

[0078] In addition, as an extension:

[0079] When two adjacent strong cold junction areas 3-2 overlap or the distance between them is smaller than the distance between two adjacent freezing sleeves 2 in the weak cold junction area 3-1, the two are merged or the area between them is replaced with the strong cold junction area 3-2 to form a combined strong cold junction area 3-4;

[0080] When two adjacent weak cold junction areas 3-1 overlap or the spacing between them is smaller than the spacing between two adjacent freezing sleeves 2 in the weak cold junction area 3-1, the two are merged or the area between them is replaced with the weak cold junction area 3-1 to form a combined weak cold junction area 3-3.

[0081] S3. After the freezing of the cold junction area, the weak cold junction area 3-1 and the steel pipe group 8 is completed, they are overlapped into a freezing circle 3, the opening part of the steel pipe group 8 is cut, the soil between the pipes is excavated, and finally the adjacent steel pipe groups 8 are connected and closed.

[0082] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A tunnel freezing casing using a pipe-roof structure method, characterized in that: include: A freezing pipe, the open end of which is provided with an orifice device, the orifice device is provided with a refrigerant outlet, and the refrigerant outlet is connected to a loop pipe of an external freezing system; A liquid supply pipe has one end extending into the freezing pipe and the other end connected to a removal pipe of an external freezing system. The liquid supply pipe is slidably connected to the orifice device to adjust the length of the portion extending into the freezing pipe.

2. The freezing casing of the tunnel using the pipe-roof structure method according to claim 1, characterized in that: The orifice device comprises: A sealing plate, which seals the open end of the freezing pipe, wherein the sealing plate is provided with a first opening and a second opening, and the second opening is the refrigerant outlet; A connecting pipe is arranged on the sealing plate and communicated with the first opening. The liquid supply pipe passes through the connecting pipe and is slidably fitted therewith.

3. The freezing casing of the tunnel using the pipe-roof structure method according to claim 1, characterized in that: Valves are provided on the return pipe and the outgoing pipe.

4. Application of the freezing sleeve as described in any one of claims 1 to 3 in freezing reinforcement construction of a combined pipe-curtain tunnel.

5. A freezing sleeve assembly for a tunnel using a pipe-roof structure method, comprising two sets of freezing sleeves according to any one of claims 1 to 3, characterized in that: The two groups of freezing sleeves are arranged opposite to each other, and the sealed ends of the freezing pipes are cross-lapped.

6. A tunnel longitudinal segment maintenance freezing structure using a pipe-roof structure method, comprising a plurality of freezing sleeves as described in any one of claims 1 to 3, characterized in that: The freezing sleeve extends into the stratum outside the pipe curtain steel pipe.

7. A method for longitudinal segmental maintenance freezing of a tunnel using a pipe-roof structure method, using the longitudinal segmental maintenance freezing structure as claimed in claim 6, characterized in that: The following steps are involved: S1. Drill multiple freezing holes in the ground within the range of the pipe curtain steel pipe, respectively set the freezing sleeves in the freezing holes, and connect the freezing sleeves to the external freezing system, dividing the tunnel into multiple sections along the longitudinal direction. In the initial state, one end of the liquid supply pipe is located in the innermost section; S2, continuously inputting refrigerant into each of the freezing casings through an external freezing system, so that a frozen body is formed in the formation around each of the freezing casings; S3, after the strength of the frozen body reaches the design and construction requirements, the prefabricated lining structure of the innermost section is constructed, and after the strength of the prefabricated lining structure after construction reaches the bearing requirements, the liquid supply pipe is moved outward until one end of the opening is close to the next section; S4, repeat S3, complete the construction of the prefabricated lining structure of each section in turn, until the construction of the pipe curtain in the tunnel is completed, and then pull out all the freezing casings.

8. The longitudinal segmental maintenance freezing method of the pipe-roof structure tunnel according to claim 7 is characterized in that: When the prefabricated lining structure of the pipe-curtain structure tunnel is constructed from the middle to both sides, the freezing hole in S1 penetrates the stratum, and the freezing casings are respectively arranged at both ends of the freezing hole, and the sealed ends of the two groups of freezing casings are cross-lapped.

9. The longitudinal segmental maintenance freezing method of the pipe-roof structure tunnel according to claim 7, characterized in that: The construction of the prefabricated lining structure of the section includes the cutting and connection construction of the pipe-roof steel pipes, the internal structure of the pipe-roof steel pipes and the concrete construction.

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