A tunnel curtain grouting method suitable for high-temperature strata

Abstract

The application provides a tunnel curtain grouting method suitable for high-temperature stratum, and a cooling liquid and a slurry are cooperatively injected in an inner grouting ring and an outer grouting ring, wherein the cooling liquid plays a role of cooling the stratum and pushing the slurry to advance, the slurry plays a role of plugging water gushing passages in front of a tunnel face, the two cooperatively diffuse, the diffusion range of the slurry is ensured, the water gushing passages in the designed diffusion range are plugged, the permeability of the curtain reinforced ring is reduced, high-temperature hot water in the tunnel is avoided in the excavation process, and the safety construction of the tunnel is ensured.

Description

Technical Field

[0001] This invention belongs to the field of underground engineering construction technology, and in particular relates to a tunnel curtain grouting method suitable for high geothermal strata. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] The tunnel construction environment is characterized by deep burial, high ground stress, and high ground temperature, with high ground temperature having a significant impact on tunnel construction safety. During tunnel construction, it is inevitable to expose water seepage channels in natural strata. While water at room temperature entering the tunnel through these channels can be sealed using radial grouting, in high-temperature strata, the water seepage channels exposed during tunnel excavation are high-temperature hot water, making conventional radial grouting methods difficult. Therefore, to ensure the safe construction of the tunnel and the safety of on-site personnel, curtain grouting must be carried out in advance when the tunnel passes through high-temperature strata to seal the high-temperature water seepage channels in front of the tunnel face and prevent the exposure of high-temperature water during tunnel excavation. Conventional curtain grouting methods face the following problems when applied to high-temperature strata: 1. Grouting materials exhibit a characteristic of increasing responsiveness with rising temperature, but fail to solidify or become ineffective after exceeding the critical temperature; 2. Grouting materials solidify in high-temperature environments, resulting in low strength of the solidified mass, making it difficult to effectively reinforce the strata; 3. High-temperature environments affect the setting time of the grout. Within a certain temperature range, the setting time of the grout decreases with increasing ambient temperature. High temperatures lead to shorter grout diffusion distances, reducing the ability to seal water inflow channels and making it difficult to achieve the designed diffusion and sealing range. In some cases, the grout may even solidify rapidly after entering the grouting pipe, causing blockage. Summary of the Invention

[0004] To overcome the shortcomings of the prior art, the present invention provides a tunnel curtain grouting method suitable for high geothermal strata. Before the grout is injected, a cooling liquid is injected into the inner ring hole to pre-cool the grouting pipe area of ​​the outer ring hole, which solves the problem of grout failure or failure to solidify. At the same time, it avoids the situation where the grout solidifies rapidly and blocks the grouting pipe when the stratum temperature is too high.

[0005] To achieve the above objectives, a first aspect of the present invention provides a tunnel curtain grouting method suitable for high geothermal strata, comprising:

[0006] Step 1: Construct a grout-stopping wall at the working face, and determine the inner and outer grouting rings on the grout-stopping wall;

[0007] Step 2: Inject cooling liquid into the inner grouting hole of the inner grouting ring, and perform grouting in the outer grouting hole of the outer grouting ring;

[0008] Step 3: When the grouting of the outer grouting hole of the outer grouting ring reaches the design completion standard, stop the injection of cooling liquid into the inner grouting hole of the inner grouting ring;

[0009] Step 4: Stop grouting the external grouting holes when the grouting pressure of the external grouting ring remains constant or the grouting volume is zero;

[0010] Step 5: After the inner grouting ring of the previous cycle is completed, it becomes the outer grouting ring of the next cycle. Repeat steps 1 to 4 until the curtain grouting work at the working face is completed.

[0011] The above one or more technical solutions have the following beneficial effects:

[0012] In this invention, before the grout is injected, a cooling liquid is injected into the inner ring hole to pre-cool the area of ​​the grouting pipe in the outer ring hole, which solves the problem of grout failure or failure to solidify, and at the same time avoids the situation where the grout solidifies rapidly and blocks the grouting pipe when the formation temperature is too high.

[0013] In this invention, cooling liquid is injected in advance through the inner ring hole, so that the grout injected through the outer ring hole enters the formation at room temperature. As the grouting process proceeds, the grout gradually solidifies. The grout is not affected by high temperature during the solidification process, thus ensuring the strength of the stone body.

[0014] In this invention, a cooling liquid and grout are injected together in the inner and outer grouting rings. The cooling liquid cools the stratum and propels the grout forward, while the grout blocks the water inflow channels in front of the tunnel face. The two work together to ensure the diffusion range of the grout, block the water inflow channels within the designed diffusion range, reduce the permeability of the curtain reinforcement ring, and prevent high-temperature hot water from entering the tunnel interior during excavation, thus ensuring the safe construction of the tunnel.

[0015] Advantages of additional aspects 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

[0016] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0017] Figure 1 This is a flowchart of a tunnel curtain grouting method suitable for high geothermal strata according to Embodiment 1 of the present invention;

[0018] Figure 2 This is a schematic diagram of the inner grouting ring and the outer grouting ring in Embodiment 1 of the present invention;

[0019] In the diagram, 1. Tunnel outline, 2. Grout stop wall, 3. First grouting ring, 31. Hole 1 of the first grouting ring, 32. Hole 2 of the first grouting ring, 33. Hole 3 of the first grouting ring, 4. Second grouting ring, 41. Hole 1 of the second grouting ring, 42. Hole 2 of the second grouting ring, 43. Hole 3 of the second grouting ring, 5. Third grouting ring, 51. Hole 1 of the third grouting ring, 52. Hole 2 of the third grouting ring, 53. Hole 3 of the third grouting ring, 6. Center hole. Detailed Implementation

[0020] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0022] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0023] Example 1

[0024] This embodiment discloses a tunnel curtain grouting method suitable for high geothermal strata, including:

[0025] Step 1: Construct a grout-stopping wall at the working face, and determine the inner and outer grouting rings on the grout-stopping wall;

[0026] Step 2: Inject cooling liquid into the inner grouting hole of the inner grouting ring, and perform grouting in the outer grouting hole of the outer grouting ring;

[0027] Step 3: When the grouting of the outer grouting hole of the outer grouting ring reaches the design completion standard, stop the injection of cooling liquid into the inner grouting hole of the inner grouting ring;

[0028] Step 4: Stop grouting the external grouting holes when the grouting pressure of the external grouting ring remains constant or the grouting volume is zero;

[0029] Step 5: After the inner grouting ring of the previous cycle is completed, it becomes the outer grouting ring of the next cycle. Repeat steps 1 to 4 until the curtain grouting work at the working face is completed.

[0030] Combination Figure 1 This embodiment provides a detailed description of a tunnel curtain grouting method suitable for high geothermal strata, specifically including:

[0031] S1: Determine the water abundance and water temperature in front of the working face;

[0032] Advanced geological forecasting work was carried out at the tunnel face to determine the water abundance ahead of the tunnel face, and advanced boreholes were drilled to detect the water temperature ahead of the tunnel face using thermometers.

[0033] S2: When the water volume and temperature in front of the working face are large, the curtain grouting construction process is adopted. Before the curtain grouting, the grout stop wall 2 is poured on the working face. The grout stop wall 2 is measured and laid out to determine the position of the curtain grouting drilling hole on the grout stop wall 2 and mark it.

[0034] According to the curtain grouting hole design drawing, all grouting holes are located and marked on the grout stop wall to facilitate rapid drilling during the curtain grouting process.

[0035] S3: Make holes at the marked positions to the designed depth, with the holes being the two adjacent holes on the adjacent grouting rings;

[0036] The number of holes opened on the grout stop wall at the same time shall not exceed two, and they must be two adjacent grouting holes on adjacent grouting rings. Other holes shall be sealed with flanges when not in use.

[0037] When the inner ring hole is located on the central axis of the two outer ring holes, injecting cooling fluid into the inner ring hole can satisfy the sequential grouting of the two closest outer ring holes. Specifically, when the inner ring hole and the outer ring holes are on a straight line, one inner ring hole corresponds to one outer ring hole for coordinated grouting; when the inner ring hole is on the central axis of the two outer ring holes, grouting in the inner ring hole can affect the diffusion range of the two outer ring holes, thus allowing grouting of both outer ring holes.

[0038] like Figure 2 As shown, a grout-stopping wall 2 is poured within the tunnel outline 1. The first grouting ring 3 on the grout-stopping wall 2 is the outer grouting ring, with outer ring holes such as hole 31 of the first grouting ring 1, hole 32 of the first grouting ring 2, and hole 33 of the first grouting ring 3. The second grouting ring 4 is the inner grouting ring, with inner ring holes such as hole 41 of the second grouting ring 1, hole 42 of the second grouting ring 2, and hole 43 of the second grouting ring 3.

[0039] S4: Place a thermometer in the middle of the outer ring hole, connect the inner ring hole to the cooling tube, inject cooling liquid into the cooling tube, and monitor the temperature change of the thermometer in the outer ring hole.

[0040] S5: After the temperature inside the outer ring hole drops to room temperature, the thermometer inside the outer ring hole is removed, the grouting pipe is connected to the outer ring hole and grouting begins.

[0041] The injection pressure of the cooling fluid in the inner ring hole should be equal to the grouting pressure in the outer ring hole. After the grouting of the outer ring hole begins, the injection pressure of the cooling fluid in the inner ring hole should gradually decrease.

[0042] The grout injected into the grouting pipe can be made of cement-water glass double-liquid grout, cement single-liquid grout, ultrafine cement, etc., while the cooling liquid injected into the cooling pipe can be condensate.

[0043] S6: After the grouting of the outer ring hole reaches the design completion standard, the injection of cooling liquid in the inner ring hole is stopped;

[0044] S7: Stop grouting the outer ring holes when the grouting pressure remains constant or the grouting volume drops to zero;

[0045] S8: Remove the grouting pipe on the outer ring hole and the cooling pipe on the inner ring hole to complete the grouting of one grouting hole on the outer ring of the grouting. Repeat this process to complete the grouting of all grouting holes on the outer ring of the curtain grouting.

[0046] S9: Have all the grouting holes on the same grouting ring been grouted? If not, open other adjacent holes on the inner and outer grouting rings and repeat the grouting steps of S4-S8.

[0047] For example, the second grouting ring 4 is the outer grouting ring, with outer ring holes such as hole 41 of the second grouting ring 1, hole 42 of the second grouting ring 2, and hole 43 of the second grouting ring 3; the third grouting ring 5 is the inner grouting ring, with inner ring holes such as hole 51 of the third grouting ring 1, hole 52 of the third grouting ring 2, and hole 53 of the third grouting ring 3.

[0048] S10: If so, the thermometer is placed in the inner ring hole, and the inner ring hole becomes the outer ring hole of the next cycle. At the same time, an inner ring hole is drilled in the outer ring hole, and the two holes are adjacent. The inner and outer rings are grouted using the grouting steps of steps S4-S9 to complete the grouting work of all grouting holes on the working face except for the center hole 6.

[0049] S11: Connect the grouting pipe to the center hole and start grouting. When the grouting end standard is reached, stop grouting, remove the grouting pipe, and the grouting work of the working face curtain is completed.

[0050] (1) This disclosure can achieve the effect of blocking and filling the water inflow channel in high geothermal strata, improving the permeability of high geothermal strata, closing the hydraulic connection channel in front of the tunnel excavation, and playing the purpose of blocking water and reinforcing the strata, so as to ensure the safety of tunnel construction and subsequent operation in high geothermal strata.

[0051] (2) This disclosure solves the problem of grout failure or failure to solidify by pre-injecting cooling liquid into the inner ring hole before grout injection to pre-cool the area of ​​the outer ring hole grouting pipe. At the same time, it avoids the situation where the formation temperature is too high and the grout solidifies rapidly when it enters the grouting pipe, thus blocking the grouting pipe.

[0052] (3) This invention injects cooling liquid into the inner ring hole in advance, so that the grout injected into the outer ring hole enters the formation at room temperature. As the grouting process proceeds, the grout gradually solidifies. The grout is not affected by high temperature during the solidification process, thus ensuring the strength of the stone body.

[0053] (4) In this disclosure, a cooling liquid and grout are injected in tandem. The cooling liquid cools the stratum and pushes the grout forward, while the grout blocks the water inflow channel in front of the tunnel face. The two work together to ensure the diffusion range of the grout, block the water inflow channel within the designed diffusion range, reduce the permeability of the curtain reinforcement ring, and prevent high-temperature hot water from entering the tunnel during the excavation process, thus ensuring the safe construction of the tunnel.

[0054] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0055] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A tunnel curtain grouting method suitable for high-geotemperature formations, characterized in that, include: Step 1: Construct a grout-stopping wall at the working face and determine the inner and outer grouting rings on the grout-stopping wall; if the inner hole of the inner grouting ring is located on the central axis of the two outer holes of the outer grouting ring, after the cooling liquid is injected into the inner hole of the inner grouting ring, the two outer holes of the outer grouting ring that are closest to each other are opened and grouted in sequence. Step 2: Inject cooling liquid into the inner grouting hole of the inner grouting ring, and perform grouting in the outer grouting hole of the outer grouting ring; the injection pressure of cooling liquid in the inner ring hole of the inner grouting ring is equal to the injection pressure in the outer ring hole of the outer grouting ring. After the grouting in the outer ring hole of the outer grouting ring begins, the injection pressure of cooling liquid in the inner ring hole of the inner grouting ring gradually decreases. Step 3: When the grouting of the outer grouting hole of the outer grouting ring reaches the design completion standard, stop the injection of cooling liquid into the inner grouting hole of the inner grouting ring; Step 4: Stop grouting the external grouting holes when the grouting pressure of the external grouting ring remains constant or the grouting volume is zero; Step 5: After the inner grouting ring of the previous cycle is completed, it becomes the outer grouting ring of the next cycle. Repeat steps 1 to 4 until the curtain grouting work at the working face is completed.

2. A method of tunnel curtain grouting suitable for high geothermal formations as claimed in claim 1, wherein, The inner grouting hole of the inner grouting ring and the outer grouting hole of the outer grouting ring are two adjacent grouting holes on the connected grouting ring.

3. A method for tunnel curtain grouting suitable for high ground temperature formations as claimed in claim 1, characterized in that, In step 2, a thermometer is placed in the outer grouting hole of the outer grouting ring. After the temperature of the outer grouting hole of the outer grouting ring drops to room temperature as monitored by the thermometer, the thermometer is removed from the outer grouting hole of the outer grouting ring, and grouting of the outer grouting hole of the outer grouting ring begins.

4. A method of tunnel curtain grouting suitable for high geotemperature formations as claimed in claim 2, characterized in that, No more than two holes should be opened on the grout-stopping wall at the same time, and other holes should be sealed when not in use.

5. A method for tunnel curtain grouting suitable for high ground temperature formations as claimed in claim 1, wherein, In step 5, grouting is finally performed in the center hole of the grout stop wall until the grouting end standard is met, thus completing the grouting work of the working face curtain.

6. A method of tunnel curtain grouting suitable for high geotemperature formations as claimed in claim 1, characterized in that, The grout used for grouting can be one of the following: cement-water glass two-component grout, cement single-component grout, or ultrafine cement.

7. A method for tunnel curtain grouting suitable for high ground temperature formations as claimed in claim 1, wherein, The cooling liquid is condensate.

8. A method of tunnel curtain grouting suitable for high geotemperature formations as claimed in claim 1, characterized in that, If the inner hole of the inner grouting ring and the outer hole of the outer grouting ring are on a straight line, then one inner hole of the inner grouting ring will be used for coordinated grouting in accordance with one outer hole of the outer grouting ring.

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