A tunnel directional splitting grouting method

Abstract

The application discloses a tunnel directional splitting grouting method, and selects a grouting contour line and a pressure reduction contour line on a tunnel face, wherein the grouting contour line and the pressure reduction contour line are both arc-shaped, the arc mouths of the grouting contour line and the pressure reduction contour line both face downward, the pressure reduction contour line is located in the arc of the grouting contour line, a plurality of grouting hole drilling sites are selected on the grouting contour line, and a plurality of pressure reduction hole drilling sites are selected on the pressure reduction contour line; the pressure reduction holes are drilled in sequence one by one, and after one pressure reduction hole is drilled, a grouting hole close to the pressure reduction hole is drilled, and after each grouting hole is drilled, the grouting hole is grouted, and the grouting of all grouting holes is completed; wherein each pressure reduction hole and grouting hole is diffusedly drilled to the end of the pressure reduction hole and grouting hole, and the end of the pressure reduction hole and grouting hole extends into the vault of the tunnel; after the grout is solidified, the grouted tunnel face is excavated, the excavation depth is less than the length of the grouting hole, and the vault of the tunnel is reinforced and water is stopped during construction.

Description

Technical Field

[0001] This invention belongs to the field of tunnel construction technology, and particularly relates to a method for directional splitting grouting in tunnels. Background Technology

[0002] In tunnel construction, deep-hole grouting is often used to reinforce the surrounding rock and tunnel face to ensure its stability, while also aiming to achieve a certain degree of water-stopping effect. Currently, the conventional method for deep-hole grouting involves drilling grouting holes approximately 12 meters deep, grouting through drill rods, or grouting the hole after removing the drill rods. In silt, silty clay, clay, and sand layers, the spacing between grouting holes is generally about 30 cm. After high-pressure grouting, the grout splits the soil and extends within it, forming grout veins. The direction of grout vein extension is often uncertain due to factors such as ground stress and geological structure, and may extend towards the ground, horizontally, or obliquely. After multi-hole grouting is completed, vertical grout veins, horizontal grout veins, or a network of grout veins may appear. In engineering, to achieve a water-stopping effect, it is desirable for the grout veins to extend horizontally so that the grout veins from each borehole connect to form a closed shell structure, but this is generally difficult to achieve. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a directional splitting grouting method that is easy to construct and can reinforce and stop water in the tunnel arch soil after construction.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: a method for directional splitting grouting in tunnels, comprising the following steps:

[0005] Step 1: Select the grouting contour line and the pressure relief contour line on the tunnel face respectively. Both the grouting contour line and the pressure relief contour line are arc-shaped and their arc openings face downwards. The pressure relief contour line is located inside the arc of the grouting contour line. Select multiple grouting hole drilling sites on the grouting contour line and multiple pressure relief hole drilling sites on the pressure relief contour line.

[0006] Step 2: Drill pressure relief holes one by one in sequence. After each pressure relief hole is drilled, drill the grouting hole next to it. After each grouting hole is drilled, grout it until all grouting holes are grouted. Each pressure relief hole and grouting hole is drilled in a diffused manner until its end extends into the arch of the tunnel.

[0007] Step 3: After the grout has solidified, excavate the face of the tunnel after grouting, and the excavation depth shall be less than the length of the grouting hole;

[0008] Step 4: Repeat steps 1, 2 and 3 in sequence until the tunnel is completed.

[0009] In step 1, the grouting contour line and the decompression contour line are coaxially distributed.

[0010] In step 1, the distance between two adjacent grouting holes is 30-50cm.

[0011] In step 1, the number of grouting holes and pressure relief holes are the same and correspond one-to-one. Each pressure relief hole is close to the corresponding grouting hole. Preferably, the pressure relief hole located at the end of the pressure relief contour line is located between two adjacent grouting holes at the same end; or a pressure relief hole is drilled between any two adjacent grouting holes.

[0012] In step 2, the drilling sequence of the pressure relief holes is either from both sides of the working face toward the middle, or from the middle of the working face toward both sides.

[0013] In step 3, the excavation of the working face can be carried out until the vertical face is close to the vertical face where the ends of the multiple grouting holes are located.

[0014] The beneficial effects of this invention are as follows: During tunnel excavation, multiple grouting holes and multiple pressure-reducing holes are pre-drilled on the tunnel face, and these holes are distributed in an arc shape. The grouting holes are distributed along the arc-shaped grouting contour line, and the pressure-reducing holes are distributed along the arc-shaped pressure-reducing contour line. The pressure-reducing contour line is located within the arc of the grouting contour line. Both the pressure-reducing holes and the grouting holes are drilled in a divergent manner, with their ends extending into the tunnel arch. By setting the pressure-reducing holes, directional grouting can be achieved, and the grout veins form an arc-shaped grouting shell at the upper end of the tunnel face. This increases the structural strength of the tunnel arch and forms a dense water-stopping layer, which is beneficial to ensuring the safe construction of the tunnel. Attached Figure Description

[0015] Figure 1 This is a schematic diagram showing the distribution of the grouting holes and pressure-reducing holes on the working face in Embodiment 1 of the present invention;

[0016] Figure 2 This is a schematic diagram showing the distribution of the grouting holes and pressure-reducing holes on the working face in Embodiment 2 of the present invention;

[0017] Figure 3 This is a schematic diagram showing the distribution of grouting holes and pressure relief holes in the excavation direction in various embodiments of the present invention;

[0018] Figure 4 This is a schematic diagram of the projection of the grouting hole diffusion direction on the working face in Embodiment 2 of the present invention;

[0019] Figure 5 This is a schematic diagram showing the distribution of the pressure relief hole and the grouting hole located at the end in Embodiment 2 of the present invention.

[0020] In the diagram: 1. Working face; 2. Grouting outline; 21. Grouting hole; 3. Pressure relief outline; 31. Pressure relief hole. Detailed Implementation

[0021] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will be more clearly described from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0022] This embodiment provides a method for directional splitting grouting in tunnels, including the following steps:

[0023] Step 1: Select grouting contour line 2 and pressure relief contour line 3 on the tunnel face 1 respectively. Both grouting contour line 2 and pressure relief contour line 3 are arc-shaped and their arc openings face downwards. The pressure relief contour line 3 is located inside the arc of the grouting contour line 2. Select multiple grouting hole 21 drilling sites on the grouting contour line 2 and multiple pressure relief hole 31 drilling sites on the pressure relief contour line 3.

[0024] Step 2: Drill the pressure relief holes 31 one by one in sequence. After drilling each pressure relief hole 31, drill the adjacent grouting hole 21. After drilling each grouting hole 21, grout it immediately until all grouting holes 21 are grouted. Each pressure relief hole 31 and grouting hole 21 is drilled in a diffused pattern (e.g., ...). Figure 3 and Figure 4 As shown, the pressure relief holes and grouting holes are not drilled along the excavation direction, but rather their ends extend outwards along the excavation direction into the tunnel arch.

[0025] Step 3: After the grout has solidified, excavate the grouting face 1, ensuring the excavation depth is less than the length of the grouting hole 21 (e.g., ...). Figure 3 As shown, there is a local overlap between the two sets of grouting holes constructed successively, which makes the reinforcement effect of the entire tunnel better.

[0026] Step 4: Repeat steps 1, 2 and 3 in sequence until the tunnel is completed.

[0027] In step 1, the grouting contour line 2 and the pressure relief contour line 3 are coaxially distributed.

[0028] In step 1, the distance between two adjacent grouting holes 21 is 30-50cm (the distance on the grouting outline, i.e., the non-linear distance).

[0029] In step 1, the number of grouting holes 21 and pressure-reducing holes 31 are the same and correspond one-to-one, with each pressure-reducing hole 31 close to its corresponding grouting hole 21 (see details). Figure 2 As shown), preferably, the pressure relief hole 31 located at the end of the pressure relief contour line 3 is located between two adjacent grouting holes 21 at the same end (see details). Figure 5 (as shown); or a pressure relief hole 31 can be drilled between any two adjacent grouting holes 21 (see details). Figure 1 (As shown).

[0030] In step 2, the drilling sequence of the pressure relief holes 31 is to drill from both sides of the face 1 toward the middle, or from the middle of the face 1 toward both sides.

[0031] In step 3, the excavation of the working face 1 is carried out until its vertical surface is close to the vertical surface where the ends of the multiple grouting holes 21 are located.

[0032] Preferably, the diameters of the pressure relief hole 31 and the grouting hole 21 can be the same and both are d (so that the same type of drill bit can be used for drilling, which is more convenient), and the radial distance between the pressure relief contour line 3 and the grouting contour line 2 is less than 10d.

[0033] The grouting outline 2 is located on the tunnel face near the arch edge of the tunnel.

[0034] Preferably, the length of the grouting hole can be 10-15m.

[0035] Example 1

[0036] When the soil inside the tunnel is relatively loose, the number of pressure relief holes is one less than the number of grouting holes, and there is a pressure relief hole between two adjacent grouting holes, specifically as follows: Figure 1 As shown, when drilling, the pressure relief hole can be drilled from the middle first. When drilling the middle pressure relief hole, the grouting holes on both sides can be drilled and grouted in sequence. Then, pressure relief holes can be drilled in sequence to the sides. One grouting hole can be drilled for each pressure relief hole until all grouting holes are drilled and grouted. After the grout has solidified, the tunnel can continue to be excavated.

[0037] Example 2

[0038] When the soil inside the tunnel is relatively dense and well-cemented, the number of pressure-reducing holes is the same as the number of grouting holes, and the center of each pressure-reducing hole and the center of the corresponding grouting hole are located on the same radius of the grouting outline 2 (e.g., Figure 2 As shown in the figure, after drilling a pressure relief hole, the corresponding grouting hole is drilled, and then grouting is performed. In this embodiment, each pressure relief hole is parallel to the corresponding grouting hole, and the two ends are flush in the vertical direction.

[0039] Example 3

[0040] Based on Example 1, the pressure-reducing holes located at both ends of the pressure-reducing contour line can be drilled slightly closer to the grouting holes at the corresponding ends of the grouting contour line (i.e., the pressure-reducing holes at the ends of the pressure-reducing contour line are not located in the exact center between the two corresponding grouting holes, but are closer to the grouting holes at the ends, although the grouting holes at the ends and the pressure-reducing holes at the corresponding ends are misaligned at a certain angle in the circumferential direction of the grouting hole contour line). Similarly, based on Example 2, the pressure-reducing holes at the ends are not located on the same radius as the grouting holes at the ends of the grouting hole contour line, i.e., the grouting holes at the ends and the pressure-reducing holes at the corresponding ends are misaligned at a certain angle in the circumferential direction of the grouting hole contour line, such as... Figure 5 As shown.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A method for directional splitting grouting in tunnels, characterized in that, Includes the following steps: Step 1: Select grouting contour line (2) and decompression contour line (3) on the tunnel face (1), respectively. Both grouting contour line (2) and decompression contour line (3) are arc-shaped and their arc openings face downwards. The decompression contour line (3) is located inside the arc of the grouting contour line (2). Select drilling points for multiple grouting holes (21) on the grouting contour line (2) and select drilling points for multiple decompression holes (31) on the decompression contour line (3). Step 2: Drill the pressure relief holes (31) one by one in sequence. After each pressure relief hole (31) is drilled, drill the grouting hole (21) next to it. After each grouting hole (21) is drilled, grouting is performed on it until all grouting holes (21) are grouted. Each pressure relief hole (31) and grouting hole (21) is drilled in a diffused manner until its end extends into the arch of the tunnel. Step 3: After the grout has solidified, the grout vein forms an arc-shaped grouting shell at the upper end of the working face (1). The working face (1) after grouting is excavated, and the excavation depth is less than the length of the grouting hole (21). The working face (1) is excavated to the vertical face of the vertical face close to the vertical face of the ends of the multiple grouting holes (21) each time, so that there is a local overlap between the two sets of grouting holes (21) constructed successively. Step 4: Repeat steps 1, 2 and 3 in sequence until the tunnel is completed.

2. The method for directional splitting grouting in tunnels according to claim 1, characterized in that, In step 1, the grouting contour line (2) and the decompression contour line (3) are coaxially distributed.

3. The directional splitting grouting method for tunnels according to claim 1, characterized in that, In step 1, the distance between two adjacent grouting holes (21) is 30-50cm.

4. The method for directional splitting grouting in tunnels according to claim 1, characterized in that, In step 1, the number of grouting holes (21) and pressure relief holes (31) are the same and correspond one-to-one, with each pressure relief hole (31) close to the corresponding grouting hole (21).

5. The directional splitting grouting method for tunnels according to claim 4, characterized in that, The pressure relief hole (31) located at the end of the pressure relief contour line (3) is located between two adjacent grouting holes (21) at the same end.

6. The method for directional splitting grouting in tunnels according to claim 1, characterized in that, A pressure relief hole (31) is drilled between any two adjacent grouting holes (21).

7. The method for directional splitting grouting in tunnels according to claim 1, characterized in that, In step 2, the drilling sequence of the pressure relief hole (31) is to drill from both sides of the face (1) toward the middle, or from the middle of the face (1) toward both sides.

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