A method for post-work thawing of a frozen cutterhead, and a cutterhead and tunnel boring machine using the same method.

Abstract

This invention discloses a post-construction thawing method for a frozen cutterhead, as well as a cutterhead and tunnel boring machine using the same method. The post-construction thawing method for a frozen cutterhead includes the following steps: alternately filling the soil chamber with slag and quicklime until a first preset position is reached; continuing to inject bentonite slurry at the first preset position in the soil chamber, utilizing the neutralization of water and quicklime in the bentonite slurry to dissipate heat, and preventing the bentonite slurry from melting and settling during the thawing process; configuring a pressure regulating system to adjust according to the relationship between the soil chamber pressure and the soil-water pressure at the tunnel face, maintaining a static earth pressure between the soil chamber pressure and the tunnel face. By using alternating backfilling of slag and quicklime as a foundation, followed by the injection of bentonite slurry to dissipate heat, the frozen soil in the surrounding strata is efficiently thawed, and a static earth pressure is maintained between the soil chamber pressure and the tunnel face during the thawing process, avoiding ground heave or subsidence. This allows for efficient thawing of the frozen cutterhead after construction under various complex geological conditions.

Description

Technical Field

[0001] This invention relates to the field of tunnel shield construction technology, and in particular to a method for post-construction thawing of a frozen cutterhead, as well as a cutterhead and tunnel boring machine using the same method. Background Technology

[0002] In tunnel boring machine (TBM) frozen cutterhead construction, the system has the function of freezing the ground. By freezing and reinforcing the soil outside the cutterhead chamber, a frozen soil curtain is formed around it. Then, under the protection of the frozen soil curtain, the cutterhead can be opened and replaced at normal pressure, ensuring the safety of cutterhead replacement in complex and soft geological conditions. However, after the cutterhead freezing construction and normal pressure opening construction are completed, it is difficult to thaw the surrounding frozen soil, making it impossible to quickly resume tunneling production. Summary of the Invention

[0003] The purpose of this invention is to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes a post-construction thawing method for cryogenic cutterheads, which enables post-construction thawing of cryogenic cutterheads under various complex geological conditions.

[0004] The present invention also proposes a cutter disc using the above-described post-processing thawing method for frozen cutter discs.

[0005] The present invention also proposes a tunnel boring machine including the above-mentioned cutterhead.

[0006] A post-process thawing method for a frozen blade disc according to a first aspect embodiment of the present invention includes:

[0007] Alternately fill the soil chamber with slag and quicklime until the first preset position in the soil chamber is reached;

[0008] Based on the first preset position in the soil chamber, continue to inject bentonite slurry. Utilize the neutralization of water and quicklime in the bentonite slurry to dissipate heat, and prevent the bentonite slurry from melting and settling during the thawing process.

[0009] A pressure regulation system is configured to adjust the pressure based on the relationship between the soil pressure in the soil chamber and the soil and water pressure at the working face, so as to maintain a static soil pressure between the soil pressure in the soil chamber and the working face.

[0010] The post-construction thawing method for the frozen cutterhead according to the first aspect of the present invention has at least the following beneficial effects: by backfilling with alternating slag and quicklime as a foundation, and then injecting bentonite slurry to dissipate heat, the frozen soil in the surrounding strata is thawed efficiently, and the static earth pressure between the soil chamber pressure and the working face is maintained during the thawing process to avoid ground heave or collapse, thereby enabling efficient thawing after construction of the frozen cutterhead under various complex geological conditions.

[0011] According to the first aspect of the present invention, the post-process thawing method for the frozen cutter disc involves backfilling the soil chamber with slag to form a protective shell, and then alternately filling it with quicklime and slag.

[0012] According to the post-process thawing method of the frozen cutter head according to the first aspect embodiment of the present invention, each layer of quicklime is wrapped with slag.

[0013] According to the first aspect of the present invention, the post-process thawing method for the frozen cutter head involves alternately filling the soil chamber with slag and quicklime until it reaches halfway down the depth direction of the soil chamber.

[0014] According to the post-processing thawing method of the frozen cutter head according to the first aspect of the present invention, the remaining portion in the soil chamber is injected with the bentonite slurry.

[0015] According to the post-process thawing method for a frozen cutter head as described in the first aspect of the present invention, the viscosity of the bentonite slurry is 60s or higher.

[0016] According to the first aspect of the present invention, the method for post-work thawing of a frozen cutter head includes a pressure regulating system comprising a pressure relief valve, which is switched on and off according to the relationship between the soil chamber pressure and the soil and water pressure at the working face, so as to regulate the pressure relationship between the soil chamber pressure and the working face.

[0017] According to the first aspect of the present invention, the post-work thawing method for the frozen cutter head involves theoretical calculation of the water and soil pressure at the shutdown position in advance. The pressure regulation system further includes a pressure gauge disposed outside the soil chamber, and a pressure relief valve is controlled according to the relationship between the pressure of the soil chamber and the water and soil pressure at the working face as displayed by the pressure gauge.

[0018] According to a second aspect of the present invention, a cutter head includes: post-work thawing of a frozen cutter head using the method described in the first aspect of the present invention for recovery after frozen construction.

[0019] A tunnel boring machine according to a third aspect of the present invention includes a cutterhead as described in the second aspect of the present invention.

[0020] It is easy to understand that the cutterhead in the second aspect embodiment of the present invention and the tunnel boring machine in the third aspect embodiment of the present invention have the same technical effects as the post-work thawing method of the frozen cutterhead in the first aspect embodiment, and therefore will not be described again.

[0021] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0023] Figure 1 This is a front view of an embodiment of the present invention;

[0024] Figure 2 This is a side view of an embodiment of the present invention.

[0025] Figure label:

[0026] 100g earthen silo, 200g slag, 300g quicklime, 400g bentonite slurry. Detailed Implementation

[0027] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0028] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0029] In the description of this invention, "several" means one or more, "more than" means at least two, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0030] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0031] Reference Figures 1-2 The post-construction thawing method for a frozen cutterhead according to a first aspect of the present invention is applied to the efficient thawing of a frozen cutterhead after construction, in order to assist in the resumption of tunneling after the cutterhead has been frozen during construction. The post-construction thawing method for a frozen cutterhead includes the following steps:

[0032] After the tunnel boring machine completes the opening of the normal pressure freezing chamber, the frozen soil in the soil chamber 100 is cleaned up, and the slag 200 is filled first. The slag 200 and quicklime 300 are alternately filled in the soil chamber 100 until the first preset position in the soil chamber 100 is reached.

[0033] Based on the first preset position within the soil chamber 100, continue to inject bentonite slurry 400. According to the principle of CaO+H2O=Ca(OH)2+Q, quicklime 300 releases heat when it comes into contact with water. The water in the bentonite slurry 400 neutralizes the quicklime 300 and releases heat, which efficiently thaws the frozen soil in the surrounding strata. At the same time, the bentonite slurry 400 has a preset viscosity that can prevent melting and settling during the thawing process.

[0034] A pressure regulation system is configured, and hourly observations are conducted. The system is adjusted based on the relationship between the pressure of the soil chamber 100 and the soil and water pressure at the working face to maintain static soil pressure between the soil chamber 100 and the working face, thus preventing ground heave or subsidence.

[0035] The foundation is constructed by alternating backfilling with 200g of slag and 300g of quicklime, followed by the injection of 400g of bentonite slurry to dissipate heat and efficiently thaw the frozen soil in the surrounding strata. During the thawing process, the pressure of the soil chamber 100g is maintained between the soil chamber and the face to keep the static soil pressure in place, preventing ground heave or collapse. This allows for efficient thawing after the construction of the frozen cutterhead under various complex geological conditions.

[0036] In a specific construction embodiment of the present invention, since CaO+H2O=Ca(OH)2+Q, it is necessary to calculate the amount of quicklime 300 in the soil chamber 100, and the heat generated must be able to completely melt the surrounding frozen soil layer.

[0037] The calculations for permafrost thawing are as follows:

[0038] The reinforcement thickness of the frozen soil layer, calculated according to the Japan JET GROUT Association (JJGA) standard, is 0.72m, and the volume of frozen soil is 3.14 × 2.75 × 2.75 × 0.72 = 10.69m³. 3 .

[0039] Enthalpy: The enthalpy of formation of CaO is -635.6 kJ / mol, the enthalpy of formation of Ca(OH)2 is -986.5 kJ / mol, and the enthalpy of formation of H2O is -285.38 kJ / mol.

[0040] Molar mass: CaO is 56 g / mol, Ca(OH)2 is 74 g / mol, and H2O is 18 g / mol.

[0041] Assuming complete reaction with 100g CaO, then 32.14g of H2O is required.

[0042] The reaction heat formula is: -986.5×(132.14 / 74)-(-635.6)×(100 / 56)-(-285.38)×(32.14 / 18) =-116.19kJ

[0043] The molar mass of ice is 18 g / mol, and its density is 0.9 g / cm³. 3 Its heat of fusion is 335 kJ / kg.

[0044] Then 1m 3 Ice requires 0.9 × 10⁻⁶ seconds to melt. 3 / m 3 ×1m 3 =900kg, melting requires 900×335kJ / kg=301500kJ, 1kgCaO can release 1161.9kJ.

[0045] The calculation shows that the required CaO is 259.48 kg.

[0046] In some embodiments of the present invention, a protective shell is formed by backfilling the soil chamber 100 with slag soil 200, followed by alternating filling with quicklime 300 and slag soil 200. The slag soil 200 completely covers the contact surface with the perimeter of the soil chamber 100, preventing the quicklime 300 from heating up and scorching the soil chamber 100 when it comes into contact with water. Therefore, after the alternating backfilling is completed, each layer of quicklime 300 is completely covered by slag soil 200.

[0047] In some embodiments of the present invention, slag soil 200 and quicklime 300 are alternately filled into the soil chamber 100 until it reaches halfway down the depth direction of the soil chamber 100. The remaining portion of the soil chamber 100 is then filled with bentonite slurry 400. Since the bentonite slurry 400 contains water, under the condition that the viscosity of the bentonite slurry 400 is at a certain value, the water will react with the quicklime 300, and the bentonite slurry 400 will continue to remain in the upper part. Preferably, based on the physical properties of the quicklime 300, water, and slag soil 200, a viscosity of 60s or higher for the bentonite slurry 400 is sufficient to prevent the bentonite slurry 400 from settling during thawing.

[0048] In some embodiments of the present invention, the pressure regulating system includes a pressure relief valve, which opens and closes according to the relationship between the pressure in the soil chamber 100 and the soil and water pressure at the working face, thereby regulating the pressure relationship between the soil chamber 100 and the working face. Before thawing, the soil and water pressure at the shutdown location is theoretically calculated in advance. The pressure regulating system also includes a pressure gauge located outside the soil chamber 100, which controls the pressure relief valve in a timely manner according to the relationship between the pressure in the soil chamber 100 and the soil and water pressure at the working face as displayed by the pressure gauge, maintaining a static soil pressure between the soil chamber 100 and the working face.

[0049] A safe and efficient post-construction thawing technology for frozen cutterheads mainly includes the alternating backfilling of slag 200 and quicklime 300 in the soil chamber 100, the injection of bentonite slurry 400 and the dissipation of heat, maintaining the pressure balance between the soil chamber 100 and the water and soil pressure at the tunnel face. This technology is the key implementation part of the entire efficient thawing method, and can carry out efficient thawing of frozen cutterheads under various complex geological conditions. It is a major technological breakthrough for resuming tunneling after frozen construction of tunnel boring machines.

[0050] Reference Figures 1-2 The cutterhead of the second aspect of the present invention may be a frozen cutterhead for a tunnel boring machine. The cutterhead is restored after the frozen construction using the post-construction thawing method of the frozen cutterhead of the first aspect of the present invention.

[0051] Reference Figures 1-2 The tunnel boring machine according to a third aspect of the present invention includes: a cutterhead as described in the second aspect of the present invention.

[0052] It is easy to understand that the cutterhead in the second aspect embodiment of the present invention and the tunnel boring machine in the third aspect embodiment of the present invention, after being restored by the post-work thawing method of the frozen cutterhead in the first aspect embodiment, have the same technical effect as the post-work thawing method of the frozen cutterhead in the first aspect embodiment, and therefore will not be described again.

[0053] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0054] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A method for post-process thawing of a frozen blade tray, characterized in that, Includes the following steps: The soil chamber was backfilled with slag to form a protective shell; Then, quicklime and slag are alternately filled into the soil chamber until the first preset position in the soil chamber is reached, where each layer of quicklime is covered by slag. Based on the first preset position in the soil chamber, continue to inject bentonite slurry. Utilize the neutralization of water and quicklime in the bentonite slurry to dissipate heat, and prevent the bentonite slurry from melting and settling during the thawing process. A pressure regulation system is configured to adjust the pressure based on the relationship between the soil pressure in the soil chamber and the soil and water pressure at the working face, so as to maintain a static soil pressure between the soil pressure in the soil chamber and the working face.

2. The post-process thawing method for the frozen blade disc according to claim 1, characterized in that: The first preset position is halfway down the depth direction of the soil chamber.

3. The post-process thawing method for the frozen blade disc according to claim 1, characterized in that: The remaining portion of the soil chamber is then filled with the bentonite slurry.

4. The post-process thawing method for the frozen blade disc according to any one of claims 1 to 3, characterized in that: The viscosity of the bentonite slurry is above 60s.

5. The post-process thawing method for the frozen blade disc according to claim 4, characterized in that: The pressure regulation system includes a pressure relief valve, which is opened and closed according to the relationship between the soil pressure in the soil chamber and the water and soil pressure at the working face, so as to regulate the pressure relationship between the soil pressure in the soil chamber and the working face.

6. The post-process thawing method for the frozen blade disc according to claim 5, characterized in that: The water and soil pressure at the shutdown location is theoretically calculated in advance. The pressure regulation system also includes a pressure gauge installed outside the soil chamber. The pressure relief valve is controlled according to the relationship between the pressure of the soil chamber and the water and soil pressure at the working face as displayed by the pressure gauge.

7. A cutter head, characterized in that, include: The recovery after frozen construction is carried out using the post-work thawing method for the frozen cutter head as described in any one of claims 1 to 6.

8. A tunnel boring machine, characterized in that, include: The cutter head as described in claim 7.

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