Shield tunneling machine capable of replacing main drive seal under normal pressure and replacing method thereof

Abstract

The invention discloses a shield tunneling machine capable of replacing a main drive seal under normal pressure and a replacement method of the shield tunneling machine. The shield tunneling machine comprises a shield tunneling machine body; each freezing pipe penetrates out of the shield tunneling machine main body, is inserted into a surrounding soil body, then penetrates back to the shield tunneling machine main body from the soil body and is connected end to end to form a loop; refrigerating fluid circulates in the freezing pipe in a circulating mode. The freezing pipe extends into the soil body to form a circulation loop, the surrounding soil body is frozen, and a freezing reinforcement curtain is formed, so that the surrounding soil body is stable in structure, soil body collapse is avoided, conditions for manually replacing a main drive seal under normal pressure are created, and harm to the body of an operator is small.

Description

Technical Field

[0001] The present invention relates to the field of shield machines, and in particular to a shield machine capable of replacing a main drive seal under normal pressure and a replacement method thereof. Background Art

[0002] Shield tunneling, a key technology in tunnel construction, is widely used in tunnel construction projects such as subways and water supply pipelines. However, during long-distance tunneling through complex strata, the shield machine's main drive seal is prone to damage, necessitating replacement.

[0003] The traditional way to replace the seal is to dig a vertical shaft on the ground, or vertically reinforce the stratum in front of the cutterhead, then advance the shield machine into the vertical shaft or reinforced area, and finally maintenance personnel enter the mud and water tank to carry out maintenance work.

[0004] A related search revealed that Chinese invention patent CN104564092A discloses an invention patent application titled "Method for Replacing the Main Drive Seal of a Slurry Shield in Complex Formations." The specific steps of this method are: on the propulsion axis of the shield tunnel, multiple reinforcement MJS piles are set up using the MJS (MetroJet System, all-round high-pressure jetting method) method to form a reinforced area, the shield machine cutter head is pushed into the reinforced area, and air is supplied by an air compressor until the inlet pressure equals the groundwater head pressure. The main drive seal replacement operation is performed under the inlet pressure. This method has certain limitations. First, it is only applicable to situations where the shield machine still has the ability to propel forward. Once the shield machine suddenly fails and loses the ability to propel forward, this method cannot be used. Second, the implementation of this method depends on the conditions for vertical MJS reinforcement above the shield machine. If the shield machine is located in a water area and the conditions for vertical MJS reinforcement are not met, this method cannot be used. Third, when opening a warehouse under pressure, operators need to work in an environment with higher atmospheric pressure than normal, which is very harmful to their health. Summary of the Invention

[0005] When a shield machine fails and the main drive seal needs to be replaced, the present invention freezes the surrounding soil through the discharge hole and the discharge pipe to form a frozen reinforcement curtain, so as to stabilize the surrounding soil structure and avoid soil collapse, thereby creating conditions for manual replacement of the main drive seal under normal pressure, and causing less harm to the health of the operators.

[0006] A further improvement of the present invention is that it includes: a shield machine body; a plurality of freezing pipes, each of which is inserted into the surrounding soil of the shield machine body and connected end to end to form a loop in the surrounding soil; and a refrigerant circulates in the freezing pipes.

[0007] A further improvement of the present invention is that it also includes a freezing station arranged outside the shield machine body for providing refrigerant, and the freezing station includes multiple discharge ports and multiple return ports; the number of the discharge ports and the return ports are the same as the number of the freezing pipes and correspond one to one; one end of the freezing pipe is connected to the corresponding discharge port, and the other end first penetrates into the shield machine body, then passes through the shield machine body and is inserted into the surrounding soil and then connected to the corresponding return port to form a loop.

[0008] A further improvement of the present invention is that at least one of the multiple freezing pipes is a first freezing pipe inserted into the soil in front of the shield machine body to form a loop; and at least one of the multiple freezing pipes is a second freezing pipe inserted into the soil on the side of the shield machine body to form a loop.

[0009] A further improvement of the present invention is that the freezing liquid is low-temperature brine or liquid nitrogen.

[0010] A further improvement of the present invention is that it also includes a plurality of temperature measuring tubes for measuring soil temperature, wherein the plurality of temperature measuring tubes are fixed to the outside of the shield machine body and inserted into the soil around the shield machine body.

[0011] The present invention provides a method for replacing a main drive seal of a shield machine under normal pressure, comprising the following steps:

[0012] S1. Provide a shield machine body and a plurality of freezing pipes disposed on the shield machine body, insert one end of each freezing pipe into the soil surrounding the shield machine body and connect the freezing pipes end to end with the other end of each freezing pipe to form a loop within the surrounding soil, and circulate freezing liquid within the freezing pipes until the surrounding soil freezes to form a frozen reinforcement curtain;

[0013] S2. Manually clear the frozen soil in the shield machine's mud and water compartment and excavate the working space required for replacing the main drive seal;

[0014] S3. Manually enter the mud and water tank to replace the main drive seal;

[0015] S4. Close the hatch of the mud and water tank, force thawing and pull out all frozen pipes from the soil, and thaw the frozen reinforcement curtain.

[0016] A further improvement of the present invention is that before executing step S1, a modifier is first sprayed into the soil around the shield machine body to preliminarily improve the stability of the soil around the shield machine body.

[0017] A further improvement of the present invention is that, during freezing construction, a temperature measuring tube is provided and inserted into the surrounding soil to detect the temperature of the surrounding soil in real time to determine whether a freezing reinforcement curtain is formed.

[0018] A further improvement of the present invention is that, when setting up the freezing pipe, a freezing station is provided outside the shield machine body for providing freezing liquid, and the freezing station includes multiple discharge ports and multiple return ports; the number of the discharge ports and the return ports is the same as the number of the freezing pipes and corresponds one to one; one end of the freezing pipe is connected to the corresponding discharge port, and the other end is first inserted into the shield machine body, then passed out of the shield machine body and inserted into the surrounding soil, and then connected to the corresponding return port to form a loop.

[0019] When the shield machine breaks down and the main drive seal needs to be replaced, the present invention sprays a freezing agent on the surrounding soil through the discharge hole and the discharge pipe to freeze it and form a freezing reinforcement curtain, so as to stabilize the surrounding soil structure and avoid soil collapse, thereby creating conditions for manually replacing the main drive seal under normal pressure. There is no need to create a high-pressure environment, which is less harmful to the health of the operators, and no need to set up additional support reinforcement. The environmental requirements for the soil are low, and the construction process is simpler. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a construction flow chart of the present invention;

[0021] Figure 2 This is a front view of one side of the cutterhead of the shield machine of the present invention;

[0022] Figure 3 It is a side view of the shield machine body of the present invention;

[0023] Figure 4 This is a schematic diagram of the frozen reinforcement curtain after forming according to the present invention;

[0024] In the figure: 1. Shield machine body; 2. Freezing reinforcement curtain; 3. Mud and water chamber; A. Horizontal freezing hole; B. Supplementary freezing hole; C. Advanced freezing hole; A”, horizontal freezing pipe; B”, supplementary freezing pipe; C”, advanced freezing pipe. DETAILED DESCRIPTION

[0025] like Figures 1 to 4 As shown, a shield machine capable of replacing the main drive seal under normal pressure includes: a shield machine body 1; a plurality of freezing pipes, each of which is inserted into the surrounding soil of the shield machine body 1 and connected end to end to form a loop in the surrounding soil; a refrigerant circulates in the freezing pipes.

[0026] Preferably, it also includes a freezing station arranged outside the shield machine body 1 for providing refrigerant, the freezing station includes multiple discharge ports and multiple return ports; the number of the discharge ports and the return ports are the same as the number of the freezing pipes and correspond one to one; one end of the freezing pipe is connected to the corresponding discharge port, and the other end first penetrates into the shield machine body 1, then penetrates out of the shield machine body 1 and is inserted into the surrounding soil and then connected to the corresponding return port to form a loop.

[0027] Preferably, the freezing liquid is low-temperature saline or liquid nitrogen.

[0028] In this embodiment, the freezing liquid is low-temperature brine, and the freezing station is set on the surface. The freezing station is equipped with a water pump for delivering the low-temperature brine into the freezing pipe, and a freezing tower for freezing the refluxed low-temperature brine.

[0029] like Figures 2 and 3 At least one of the multiple freezing pipes is a first freezing pipe that is inserted into the soil in front of the shield machine body 1 to form a loop; at least one of the multiple freezing pipes is a second freezing pipe that is inserted into the soil on the side of the shield machine body 1 to form a loop. By providing the first freezing pipe and the second freezing pipe, the soil on the sides and in front of the shield machine body 1 is frozen to form a stable working space. In this embodiment, the first freezing pipe includes a horizontal freezing pipe A" and a supplementary freezing pipe B", and the second freezing pipe includes an advance freezing pipe C".

[0030] In this embodiment, Figures 2 and 3 As shown, a plurality of freezing holes are provided on the shield machine body, including horizontal freezing holes A, supplementary freezing holes B and advanced freezing holes C. In this embodiment, four horizontal freezing holes A, four supplementary freezing holes B and twelve advanced freezing holes C are provided on the cutter head surface of the shield machine body 1. The four horizontal freezing holes A and the twelve advanced freezing holes C are grouting holes provided by the shield machine body 1 itself. In order to make the formed frozen reinforcement curtain 2 more stable, four supplementary freezing holes B are provided, for a total of 20 freezing holes, each of which has a plurality of horizontal freezing holes A and a plurality of supplementary freezing holes B. A freezing pipe is passed through each hole, and the freezing pipe is passed back into the shield machine body 1 from the freezing hole. The freezing pipes corresponding to the four horizontal freezing holes A and the four supplementary freezing holes B are the first freezing pipes, which extend into the soil in front of the shield machine body. The freezing pipes corresponding to the advance freezing holes C are the second freezing pipes, which extend obliquely into the soil around the side of the shield machine body 1. In this embodiment, it also includes four horizontal freezing pipes A", four supplementary freezing pipes B", and twelve advance freezing pipes C". Each freezing pipe is connected to the corresponding freezing hole.

[0031] In this embodiment, it also includes four horizontal freezing pipe sleeves, four supplementary freezing pipe sleeves and twelve advance freezing pipe sleeves, which are respectively inserted into the corresponding freezing holes and extended into the soil. The freezing pipe corresponding to each freezing hole is located in the corresponding freezing pipe sleeve. By setting the freezing pipe sleeve, the freezing pipe is prevented from directly contacting the frozen soil, and the risk of damage to the freezing pipe is reduced. In this embodiment, the freezing pipe sleeve adopts a low-carbon steel seamless steel pipe, and the freezing pipe has a pressure resistance of not less than 1.0 MPa and not less than 1.5 times the brine pressure of the freezing working surface. The freezing pipe is tightly attached to the inner wall of the freezing pipe sleeve to maximize the cooling effect and reduce the decrease in cooling effect caused by the installation of the freezing pipe sleeve.

[0032] In this embodiment, Figure 3 As shown, the horizontal freezing pipe sleeve is inserted into the soil in front of the shield machine body 1 in the horizontal direction, the supplementary freezing pipe sleeve is set obliquely forward, with an angle of 10° to the shield machine axis, and the advance freezing pipe sleeve is at an angle of 14° to the shield machine axis, extending into the surrounding soil of the shield machine body 1. In actual construction, the position of the freezing hole and the angle of the corresponding freezing pipe can be selected according to the specific model of the shield machine body 1 and the conditions of the soil, so as to generate a freezing reinforcement curtain 2 that meets the conditions.

[0033] In this embodiment, Figure 4 As shown, based on the positions of the freezing pipes, the soil is frozen, and finally a frozen reinforcement curtain 2 is formed as shown in the figure.

[0034] Preferably, it further comprises a plurality of temperature measuring tubes for measuring the temperature of the soil, wherein the plurality of temperature measuring tubes are fixed to the outside of the shield machine body 1 and inserted into the soil around the shield machine body.

[0035] This embodiment provides a method for replacing a shield machine main drive seal under normal pressure, comprising the following steps:

[0036] S1. Provide a shield machine body and multiple freezing pipes provided on the shield machine body 1. Insert one end of the freezing pipe into the soil surrounding the shield machine body, and extend the other end from the soil and return to the shield machine body to form a loop in the surrounding soil. Circulate freezing liquid in the freezing pipe until the surrounding soil freezes to form a frozen reinforcement curtain.

[0037] S2, manually clearing the frozen soil in the mud and water compartment 3 of the shield machine and excavating the working space required for replacing the main drive seal;

[0038] S3. Manually enter the mud and water tank 3 to replace the main drive seal;

[0039] S4. Close the hatch of the mud and water tank 3, force thawing and pull out all frozen pipes from the soil, and then start the shield machine to thaw the frozen reinforcement curtain.

[0040] Preferably, before executing step S1, an improver is first sprayed into the soil around the shield machine body to preliminarily improve the stability of the soil around the shield machine body. Specifically, before setting the freezing pipe, the grouting pipe is connected through the advance freezing hole C and inserted into the soil, and the improver is injected into the soil.

[0041] Preferably, in this embodiment, when performing freezing construction, a temperature measuring tube is further provided, and the temperature measuring tube is inserted into the surrounding soil to detect the temperature of the surrounding soil in real time to determine whether a freezing reinforcement curtain is formed.

[0042] In this embodiment, the design freezing time is 5 months. The actual freezing time depends on the bonding condition between the freezing wall and the shield shell. The flow rate of a single freezing hole is required to be no less than 8-10m 3 / h; after 7 days of freezing, the brine temperature must drop below -18°C; after 15 days of freezing, the brine temperature must drop below -25°C, with the temperature difference between the outgoing and return brine no greater than 2°C; after 20 days of freezing, the brine temperature must drop below -28°C, and when opening the warehouse at normal pressure, the brine temperature must drop below -30°C. If the brine temperature and flow rate do not meet the design requirements, the active freezing period should be extended. The designed heat dissipation capacity per meter of freezing pipe should not be less than 100 kcal / h.

[0043] In this example, the specific steps for replacing the main drive seal include: checking the transmission oil sample → disassembling the outer compression ring, outer lip seal and outer isolation ring in sequence, cleaning all sealing ring cavities, grease holes and pipelines → removing the rings and seals in sequence → checking the wear of the outer sealing ring → assembling and bonding the outer seal in the hole in sequence → assembling the new first outer isolation ring and second outer isolation ring in the hole, assembling the seal, isolation ring and new compression ring in sequence → carefully cleaning the transmission, lubricating the system pipelines, valve group and filter element.

[0044] This example has the following advantages: 1. It has low requirements on the function of the shield machine and can still be used when it fails and has no excavation capability; 2. It has wide applicability and is not restricted by the location of the shield machine. It can be used under buildings or under water; 3. After freezing reinforcement, maintenance personnel can replace the main bearing seal under normal pressure conditions, greatly reducing their physical harm.

[0045] Finally, it should be noted that the above are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A shield machine capable of replacing the main drive seal under normal pressure, characterized in that: include: Shield machine main body; A plurality of freezing pipes are each inserted into the surrounding soil of the shield machine body and connected end to end to form a loop in the surrounding soil; and a refrigerant circulates in the freezing pipes.

2. The shield machine capable of replacing the main drive seal under normal pressure according to claim 1, characterized in that: It also includes a freezing station arranged outside the shield machine body for providing refrigerant, and the freezing station includes multiple discharge ports and multiple return ports; the number of the discharge ports and the return ports is the same as the number of the freezing pipes and corresponds one to one; one end of the freezing pipe is connected to the corresponding discharge port, and the other end first passes through the shield machine body, then passes through the shield machine body and is inserted into the surrounding soil, and then connected to the corresponding return port to form a loop.

3. The shield machine capable of replacing the main drive seal under normal pressure according to claim 2, characterized in that: At least one of the multiple freezing pipes is a first freezing pipe inserted into the soil in front of the shield machine body to form a loop; at least one of the multiple freezing pipes is a second freezing pipe inserted into the soil on the side of the shield machine body to form a loop.

4. The shield machine capable of replacing the main drive seal under normal pressure according to claim 1, characterized in that: The freezing liquid is low-temperature salt water or liquid nitrogen.

5. The shield machine capable of replacing the main drive seal under normal pressure according to claim 1, characterized in that: It also includes a plurality of temperature measuring tubes for measuring soil temperature, wherein the plurality of temperature measuring tubes are fixed on the outside of the shield machine body and inserted into the soil around the shield machine body.

6. A method for replacing a shield machine with a main drive seal capable of being replaced under normal pressure, characterized in that: The following steps are involved: S1. Provide a shield machine body and a plurality of freezing pipes disposed on the shield machine body, insert one end of each freezing pipe into the soil surrounding the shield machine body and connect the freezing pipes end to end with the other end of each freezing pipe to form a loop within the surrounding soil, and circulate freezing liquid within the freezing pipes until the surrounding soil freezes to form a frozen reinforcement curtain; S2. Manually clear the frozen soil in the shield machine's mud and water compartment and excavate the working space required for replacing the main drive seal; S3. Manually enter the mud and water tank to replace the main drive seal; S4. Close the hatch of the mud and water tank, force thawing and pull out all frozen pipes from the soil, and thaw the frozen reinforcement curtain.

7. The method for replacing a shield machine capable of replacing a main drive seal under normal pressure according to claim 6, characterized in that: Before executing step S1, a modifier is first sprayed into the soil around the shield machine body to preliminarily improve the stability of the soil around the shield machine body.

8. The method for replacing a shield machine capable of replacing a main drive seal under normal pressure according to claim 6, wherein: During the freezing construction, a temperature measuring tube is provided and inserted into the surrounding soil to detect the temperature of the surrounding soil in real time to determine whether the freezing reinforcement curtain is formed.

9. The method for replacing a shield machine capable of replacing a main drive seal under normal pressure according to claim 6, wherein: When setting up the freezing pipe, a freezing station is provided outside the shield machine body for providing freezing liquid, and the freezing station includes multiple discharge ports and multiple return ports; the number of the discharge ports and the return ports is the same as the number of the freezing pipes and corresponds one to one; one end of the freezing pipe is connected to the corresponding discharge port, and the other end is first inserted into the shield machine body, then passed out of the shield machine body and inserted into the surrounding soil, and then connected to the corresponding return port to form a loop.

Images