Combined grouting structure and grouting method suitable for rapid blocking of tunnel leakage

Abstract

The invention discloses a combined grouting structure suitable for quickly plugging tunnel leakage, and relates to the field of tunnel engineering. It comprises an excavation profile and surrounding rock fissures; cement grouting holes are provided at both ends of the excavation profile, and acrylate grouting holes are provided at the excavation profile. The invention makes full use of the characteristics of cement grouting having a long solidification time but a low price, and acrylate grouting having a short solidification time but a high price, and the two are used in combination to plug groundwater leakage around tunnel support, thereby achieving practical, economical and environmentally friendly effects.

Description

Technical Field

[0001] The invention relates to the field of tunnel engineering, and more specifically to a combined grouting structure suitable for quickly plugging tunnel leakage. The invention also discloses a grouting method of the combined grouting structure suitable for quickly plugging tunnel leakage. Background Art

[0002] In the process of urban rail transit tunnel construction, in order to minimize the interference to the surrounding environment and road traffic, the tunnel construction is generally carried out by dark excavation. Depending on the different strata where the project is located, the dark excavation method often uses the mining method or shield method. The specific method needs to be comprehensively judged based on economic, technical, construction period, environmental and other conditions.

[0003] The mining method tunnel has the characteristics of flexible excavation section layout, strong adaptability to the strata, and moderate investment cost. It is often used in tunnel projects with variable excavation sections and variable strata hardness.

[0004] Depending on the specific strata, mining tunnel excavation is often carried out by blasting, mechanical or manual excavation. When encountering hard strata, blasting is required to assist in construction.

[0005] Along with the blasting construction in the tunnel, the rock mass around the tunnel section may produce rock cracks of varying sizes due to the vibration of the blasting. Under the action of groundwater, the filling material in the cracks will flow into the tunnel, causing the rock to loosen and affecting the safety of the tunnel.

[0006] When tunnel excavation encounters groundwater, it is necessary to reinforce the rock mass around the excavated tunnel by grouting to reduce groundwater leakage.

[0007] Considering that the surrounding rock is mainly impermeable rock layer with good anti-permeability, and the cracks in the surrounding rock are mainly the cracks in the rock mass itself and the cracks caused by blasting vibration, no matter which grouting and water-stopping scheme is adopted, the cracks need to be filled densely according to local conditions.

[0008] Commonly used methods for grouting reinforcement include cement slurry or cement mortar, chemical grouting and other methods, and each method needs to be selected according to the specific situation. Cement slurry or cement mortar has a long solidification time and low cost. It is difficult to accurately control the solidification time of the double liquid slurry in chemical grouting, and the cost is low. The acrylate in chemical grouting has a relatively short solidification time and high cost.

[0009] When the groundwater level is high and the water flow is large, a construction method that is fast in stopping water, economical in cost and convenient in construction is needed; therefore, it is very necessary to propose a combined grouting structure suitable for quickly blocking tunnel leakage. Summary of the invention

[0010] The first purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide a combined grouting structure suitable for quickly plugging tunnel leakage.

[0011] The second object of the present invention is to provide a grouting method for the combined grouting structure suitable for quickly plugging tunnel leakage.

[0012] In order to achieve the above-mentioned first purpose, the technical solution of the present invention is: a combined grouting structure suitable for quickly plugging tunnel leakage, characterized in that it includes: an excavation contour and surrounding rock cracks located on the excavation contour; a plurality of rows of cement grouting holes are arranged in a ring at both ends of the excavation contour, and a plurality of rows of acrylate grouting holes are arranged in a ring between the cement grouting holes on the excavation contour; the surrounding rock cracks are located between the acrylate grouting holes.

[0013] In order to achieve the above second purpose, the technical solution of the present invention is: a combined grouting method suitable for quickly plugging tunnel leakage, characterized in that it includes the following steps:

[0014] Step 1: Confirm the scope of the leakage area, carefully find the surrounding rock cracks and leakage paths in the leakage area of ​​the excavation outline, determine the location and number of grouting holes, and drill holes; drill cement grouting holes at both ends of the leakage area, and drill acrylate grouting holes in the leakage area;

[0015] Step 2: Install grouting pipes in the cement grouting holes and the acrylate grouting holes;

[0016] Step 3: Use a grouting machine to inject cement or acrylate into the grouting hole; when slurry starts to flow out of the adjacent hole, maintain the grouting pressure for a period of time, and after the slurry solidifies, stop grouting in this hole and start grouting in the adjacent grouting hole.

[0017] Step 4: After grouting of all grouting holes is completed, confirm that there is no leakage, then remove the grouting nozzle and clean the grouting equipment.

[0018] In the above technical solution, in step 2, the longitudinal spacing of the cement grouting hole ring is 1m×1m, the drilling angle of the cement grouting hole is 90° with the axis of the excavation profile; the diameter of the cement grouting hole is 46mm, and the hole depth is 5m.

[0019] In the above technical solution, in step 3, a static pressure grouting method is used for grouting of cement grouting holes, and the grouting is carried out in two sections, the first section is 2m, and the second section is 3m; grouting pressure: 0.3-0.4MPa is used in the first section, and 0.5MPa is used in the second section.

[0020] In the above technical solution, in step 3, 42.5 grade ordinary cement is used for grouting of cement grouting holes, and the slurry ratio is 1:2 to 1:0.5; when the water seepage is large, pure cement slurry mixed with water glass is used.

[0021] In the above technical solution, in step 2, the longitudinal spacing of the acrylate grouting hole ring is 1m×1m, the drilling angle of the acrylate grouting hole is 90° with the axis of the excavation profile; the diameter of the acrylate grouting hole is not less than 32mm, and the hole depth is 7m.

[0022] In the above technical scheme, in step 3, the static pressure grouting method is adopted for the grouting of the acrylate grouting holes, and the grouting is carried out in 3 sections, the first section is 2m, the second section is 2m, and the third section is 2-4m; the grouting pressure: the first section, 0.2MPa, the second section 0.25MPa, the third section 0.3MPa.

[0023] In the above technical solution, in step 3, XT-acrylate grouting material is used for grouting of acrylate grouting holes, which is prepared from three components A, B and C. Component A is acrylate, component B is a curing agent, and component C is an accelerator.

[0024] In the above technical solution, in step 3, when the XT-acrylate grouting material is prepared, the curing time is adjustable, and the fast curing takes 30s to 2min, while the slow curing time is greater than 15min.

[0025] The present invention is applicable to the case where the local tunnel seepage is large and the water pressure is high after the completion of the mining method tunnel support. The combined grouting method of cement grouting is adopted at both ends of the leakage area for plugging, and acrylate grouting is adopted for rapid water stopping in the leakage area. The characteristics of cement grouting, which has a long solidification time but a low price, and acrylate grouting, which has a short solidification time but a high price, are fully utilized. The two are used in combination to plug the groundwater leakage around the tunnel support, thereby achieving a practical, economical and environmentally friendly effect. The present invention can also be applied to the treatment of mining method tunnel leakage after the completion of the initial support or the completion of the secondary lining, and can be applied to underground projects under similar conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 for Figure 1 Cross-sectional view at AA in the middle.

[0028] Figure 3 for Figure 1 Cross-sectional view at the middle BB.

[0029] Among them, 11-drilling cement grouting hole, 12-acrylate grouting hole, 2-surrounding rock fissure, 3-excavation outline. DETAILED DESCRIPTION

[0030] The following detailed description of the implementation of the present invention is made in conjunction with the accompanying drawings, but they do not constitute a limitation of the present invention and are only given as examples. At the same time, the advantages of the present invention will become clearer and easier to understand through the description.

[0031] Referring to the attached drawings, it can be seen that the combined grouting structure suitable for quickly plugging tunnel leakage includes: an excavation profile 3, and a surrounding rock fissure 2 located on the excavation profile 3; a plurality of rows of cement grouting holes 11 are arranged in a ring at both ends of the excavation profile 3, and a plurality of rows of acrylate grouting holes 12 are arranged in a ring between the cement grouting holes 11 on the excavation profile 3; the surrounding rock fissure 2 is located between the acrylate grouting holes 12.

[0032] A combined grouting method suitable for quickly plugging tunnel leakage is characterized by comprising the following steps:

[0033] Step 1: Confirm the scope of the leakage area, carefully find the surrounding rock cracks 2 and the leakage path in the leakage area of ​​the excavation contour 3. When the tunnel has been supported by shotcrete, the concrete around the leakage point can be knocked open with a hammer to determine the location and number of grouting holes; use electric hammers and other drilling tools to drill holes around the tunnel and clean the holes; drill cement grouting holes 11 at both ends of the leakage area, and drill acrylate grouting holes 12 in the leakage area;

[0034] Step 2: Install grouting pipes in the cement grouting hole 11 and the acrylate grouting hole 12;

[0035] Step 3: Use a grouting machine to inject cement or acrylate into the grouting hole; when the adjacent hole begins to slurry out, maintain the grouting pressure for a period of time, and after the slurry solidifies, stop grouting in this hole and start injecting into the adjacent grouting hole;

[0036] Step 4: After grouting of all grouting holes is completed, confirm that there is no leakage, then remove the grouting nozzle and clean the grouting equipment.

[0037] In step 2, the longitudinal spacing of the cement grouting holes 11 is 1m×1m, and the drilling angle of the cement grouting holes 11 is 90° with the axis of the excavation profile 3 to penetrate the rock layer; the cement grouting holes 11 have a diameter of 46mm and a hole depth of 5m.

[0038] In step 3, static pressure grouting method is adopted for grouting of cement grouting hole 11, and grouting is carried out in two sections, the first section is 2m, and the second section is 3m; grouting pressure: the first section, that is, the orifice section adopts 0.3~0.4MPa, and the second section adopts 0.5MPa; when grouting, the orifice should have a suitable blocking method to ensure the grouting pressure.

[0039] In step 3, 42.5 grade ordinary cement is used for grouting the cement grouting hole 11, and the slurry ratio is 1:2 to 1:0.5; when the water seepage is large, pure cement slurry is mixed with water glass to enhance the grouting water-stopping effect.

[0040] In step 2, two rings of acrylate grouting holes 12 are arranged at the sealing water-stopping sections on both sides of the left and right tunnels. The longitudinal spacing of the acrylate grouting holes 12 is 1m×1m, and the drilling angle of the acrylate grouting holes 12 is 90° with the axis of the excavation profile 3 to penetrate the rock layer. The diameter of the acrylate grouting holes 12 is not less than 32mm, and the hole depth is 7m.

[0041] In step 3, static pressure grouting method is used for grouting of acrylate grouting hole 12, and grouting is carried out in 3 sections, the first section is 2m, the second section is 2m, and the third section is 2-4m; grouting pressure: 0.2MPa is used in the first section, i.e. the orifice section, 0.25MPa in the second section, and 0.3MPa in the third section.

[0042] In step 3, XT-acrylate grouting liquid is used for grouting the acrylate grouting hole 12, which is prepared from three components A, B and C. Component A is acrylate, component B is a curing agent, and component C is an accelerator.

[0043] In step 3, when the XT-acrylate grouting liquid is prepared, the curing time can be adjusted according to the construction environment temperature. Rapid curing takes 30s to 2min, and slow curing takes more than 15min.

[0044] The present invention is suitable for a combined grouting method in which cement grouting is used for plugging at both ends of the leakage area and acrylate grouting is used for rapid water stopping in the leakage area when a large amount of water leakage and high water pressure are encountered in a local tunnel after the completion of the mining method tunnel support. The present invention makes full use of the characteristics of cement grouting that has a long solidification time but a low price and acrylate grouting that has a short solidification time but a high price. The two are used in combination to plug groundwater leakage around the tunnel support, thereby achieving a practical, economical and environmentally friendly effect.

[0045] Cement consolidation grouting is used in cement grouting hole 11, mainly to inject the open cracks in the rock mass. After reinforcement, two annular grouting rock masses are formed along the direction of the tunnel line, which is conducive to the subsequent chemical grouting pressure and reduces the amount of chemical grouting, saving project investment; cement grouting uses shallow holes with a hole depth of 5m, mainly to deal with the weak unloading disturbance zones at both ends of the tunnel leakage area.

[0046] Acrylate grouting is used to quickly stop water in the acrylate grouting hole 12, mainly to irrigate the leakage area with high groundwater level and large water flow. Under the blocking effect of the grouting rock mass at both ends, the chemical grout penetrates into the deep rock mass along the surrounding rock cracks 2 under pressure, and the purpose of quickly closing the cracks is achieved by adjusting the grouting solidification time; the chemical grouting adopts a deeper hole with a hole depth of 7m, which is mainly used to treat the tunnel unloading area with high groundwater level and large water flow;

[0047] The XT-acrylate grouting fluid used in chemical grouting is a highly elastic gel formed with acrylate monomers as the main agent and water as the diluent under the action of certain initiators and promoters. This material does not contain the toxic components in acrylate gel and is an environmentally friendly chemical grouting material for water plugging and anti-seepage. It has low viscosity and strong penetration ability. The gel has good impermeability, viscoelasticity and aging resistance.

[0048] Other parts not described belong to the prior art.

Claims

1. A combined grouting method suitable for quickly plugging tunnel leakage, characterized in that: The invention comprises a combined grouting structure suitable for quickly plugging tunnel leakage, the combined grouting structure suitable for quickly plugging tunnel leakage comprises an excavation profile (3) and surrounding rock fissures (2) located on the excavation profile (3); a plurality of rows of cement grouting holes (11) are arranged in an annular manner at both ends of the excavation profile (3); a plurality of rows of acrylate grouting holes (12) are arranged in an annular manner between the cement grouting holes (11) on the excavation profile (3); the surrounding rock fissures (2) are located between the acrylate grouting holes (12); The method is suitable for a combined grouting method in which cement grouting is used to seal the two ends of the leakage area and acrylate grouting is used to quickly stop water in the leakage area after the completion of the mine tunnel support, and the method comprises the following steps: Step 1: Confirm the scope of the leakage area, carefully find the surrounding rock cracks (2) and the leakage path in the leakage area of ​​the excavation outline (3), determine the location and number of grouting holes, and drill holes; drill cement grouting holes (11) at both ends of the leakage area, and drill acrylate grouting holes (12) in the leakage area; Step 2: installing grouting pipes in the cement grouting hole (11) and the acrylate grouting hole (12); Step 3: Use a grouting machine to inject cement or acrylate into the grouting hole; when the adjacent hole begins to slurry out, maintain the grouting pressure for a period of time, and after the slurry solidifies, stop grouting in this hole and start injecting into the adjacent grouting hole; Step 4: After all grouting holes are grouted, confirm that there is no leakage and then remove the grouting nozzle and clean the grouting equipment; In step 3, the cement grouting hole (11) is grouted by a static pressure grouting method, and the grouting is carried out in two sections, the first section is 2m, and the second section is 3m; the grouting pressure: the first section adopts 0.3-0.4MPa, and the second section adopts a pressure of 0.5MPa; In step 3, the grouting of the acrylate grouting hole (12) is carried out by a static pressure grouting method, and the grouting is carried out in three sections, the first section is 2 m, the second section is 2 m, and the third section is 2 to 4 m; the grouting pressure is: 0.2 MPa in the first section, 0.25 MPa in the second section, and 0.3 MPa in the third section; In step 3, 42.5 grade ordinary cement is used for grouting the cement grouting hole (11), and the slurry ratio is 1:2 to 1:0.5; when the water seepage is large, pure cement slurry is mixed with water glass; In step 3, XT-acrylate grouting material is used for grouting the acrylate grouting hole (12), which is prepared from three components A, B and C. Component A is acrylate, component B is a curing agent, and component C is an accelerator.

2. The combined grouting method for rapidly plugging tunnel leakage according to claim 1 is characterized in that: In step 2, the longitudinal spacing of the cement grouting holes (11) is 1m×1m, and the drilling angle of the cement grouting holes (11) is 90° with the axis of the excavation profile (3); the diameter of the cement grouting holes (11) is 46mm, and the hole depth is 5m.

3. The combined grouting method suitable for quickly plugging tunnel leakage according to claim 2 is characterized in that: In step 2, the longitudinal spacing of the acrylate grouting holes (12) is 1m×1m, and the drilling angle of the acrylate grouting holes (12) is 90° with the axis of the excavation profile (3); the diameter of the acrylate grouting holes (12) is not less than 32mm, and the hole depth is 7m.

4. The combined grouting method suitable for quickly plugging tunnel leakage according to claim 3 is characterized in that: In step 3, when the XT-acrylate grouting material is prepared, the curing time is adjustable, and the fast curing takes 30s to 2min, while the slow curing time is greater than 15min.

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