Grouting method and grouting system for water-rich sandy gravel stratum tunnel replacement sand layer

Abstract

The invention relates to the technical field of tunnel engineering, in particular to a grouting method and a grouting system for a water-rich sandy gravel stratum tunnel replacement sand layer. The grouting method comprises the steps that a grouting hole and a sand discharging hole are drilled in the tunnel face, the grouting hole penetrates through the middle of the sand-rich area, and the sand discharging hole penetrates through the contour edge of the sand-rich area; grout is injected into the grouting holes, the grout enters the sand-rich area, and under the action of pressure, the grout carries the fine sand to be squeezed into the sand discharging holes together and discharged from the sand discharging holes; the discharged slurry and fine sand are separated, and the separated slurry is injected into the grouting holes again; and the grouting and sand discharging processes are circulated until the fine sand is not discharged out of the sand discharging holes. By means of the method, accurate replacement grouting reinforcement of the sand layer in the water-rich sandy gravel stratum is achieved, the stratum stability and the construction safety are improved, meanwhile, the construction cost is reduced, and the resource utilization rate is increased.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel engineering, and in particular to a grouting method and a grouting system for replacing a sand layer in a water-rich sand-pebble stratum tunnel. Background Art

[0002] In tunnel engineering, water-rich sand and gravel strata are a common complex geological condition, which is characterized by rich water in the strata, and the sand and gravel particles are of different sizes and unevenly distributed. This stratum is very prone to safety accidents such as sand burst and landslides during tunnel excavation, and this geological condition poses a severe challenge to traditional grouting technology.

[0003] Existing grouting technology usually uses a single grouting pipe for grouting, and the slurry penetrates into the formation under pressure. However, in water-rich sand and gravel formations, due to the strong fluidity and high density of fine sand, the slurry is often difficult to effectively diffuse to the entire sand layer area. Especially when the grouting reinforcement holes are injected into the sand-rich area with a large sand content, since the density of fine sand is much higher than that of the slurry, it is difficult for the slurry to split and enter the fine sand layer. Therefore, the traditional grouting method has limited effect, and the fine sand layer is difficult to be effectively reinforced, which still poses a great safety hazard in the subsequent excavation of the sand and gravel formation.

[0004] In order to solve the above problems, the prior art also uses horizontal high-pressure rotary grouting technology, which uses a high-pressure rotary grouting device to spray slurry into the stratum in a high-speed rotating manner to form a grouting reinforcement area within a certain range. However, the horizontal high-pressure rotary grouting technology has complex equipment, high difficulty in operation, and high economic cost. For large-scale tunnel projects, its cost-effectiveness is not ideal.

[0005] Based on the existing technology, the main technical problems include:

[0006] ① The fine sand layer is difficult to be split and penetrated by slurry due to its high density, making grouting reinforcement difficult to achieve.

[0007] ② The traditional grouting method is difficult to spread effectively in water-rich sand and gravel formations, resulting in poor reinforcement effect.

[0008] ③ The horizontal high-pressure rotary spraying technology has high cost and complex equipment and is not suitable for large-scale application. Summary of the invention

[0009] In view of the shortcomings of the prior art, the purpose of an embodiment of the present invention is to provide a grouting method for replacing sand layers in water-rich sand and gravel formations in tunnels. Through innovative grouting and fine sand replacement technology, accurate replacement grouting reinforcement of sand layers in water-rich sand and gravel formations can be achieved, thereby improving formation stability and construction safety, while reducing construction costs and improving resource utilization.

[0010] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0011] A grouting method for replacing a sand layer in a water-rich sand-pebble stratum tunnel comprises: drilling a grouting hole and a sand-draining hole on a tunnel face, the grouting hole passing through the middle of a sand-rich area, and the sand-draining hole passing through the contour edge of the sand-rich area; injecting slurry into the grouting hole, the slurry enters the sand-rich area, and under the action of pressure, the slurry carries fine sand and squeezes into the sand-draining hole together, and is discharged from the sand-draining hole; separating the discharged slurry and the fine sand, and re-injecting the separated slurry into the grouting hole; and cyclically performing the grouting and sand-draining process until no more fine sand is discharged from the sand-draining hole.

[0012] Optionally, a plurality of sand discharge holes are drilled around the grouting hole.

[0013] Optionally, after drilling, use a high-pressure water jet to clean impurities in the grouting holes and sand removal holes.

[0014] An embodiment of the present invention also provides a grouting system that adopts the above-mentioned water-rich sand and gravel stratum tunnel replacement sand layer grouting method, including: a grouting platform, a steel pipe and a slurry separation device; the steel pipe is installed in the grouting hole, the grouting platform is connected to the inlet of the steel pipe, the outlet of the sand discharge hole is connected to the slurry separation device, and the slurry discharge outlet of the separation device is connected to the grouting platform.

[0015] Optionally, the grouting platform includes a high-pressure pump and a pressure regulator, the high-pressure pump is used to provide high-pressure slurry, and the pressure regulator adjusts the grouting pressure in real time according to the density of the sand layer.

[0016] Optionally, the slurry separation device includes a horizontal spiral centrifuge and a sand outlet bin, the horizontal spiral centrifuge separates fine sand from slurry by utilizing the specific gravity difference between fine sand and slurry, and the sand outlet bin is connected to the horizontal spiral centrifuge for storing fine sand.

[0017] Optionally, the high-pressure pump is connected to the inlet of the flower steel pipe through a grouting pipe, and the outlet of the sand discharge hole is connected to the horizontal spiral centrifuge through a sand discharge pipe.

[0018] Optionally, the patterned steel pipe is provided with a slurry outlet hole, and there are multiple slurry outlet holes, and the multiple slurry outlet holes are opened on the pipe wall of the patterned steel pipe.

[0019] Optionally, a sleeve valve is installed in the slurry outlet hole, and the sleeve valve is a one-way valve. The one-way valve allows the slurry to flow from inside the pipe to outside the pipe, and blocks the flow from outside the pipe to inside the pipe.

[0020] Optionally, a fixed membrane block is provided at the inner end of the flower steel pipe, and a stop membrane block is installed on the outer wall of the flower steel pipe. The stop membrane block is located at the outer edge of the sand-rich area and is used to close the gap between the flower steel pipe and the grouting hole.

[0021] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0022] The grouting method of the present invention innovatively utilizes the synergistic effect of the sand discharge hole and the grouting hole, and efficiently discharges fine sand through the slurry replacement mechanism, thereby achieving deep reinforcement of the sand layer. This method fundamentally solves the bottleneck problem of the difficulty of slurry to penetrate the fine sand layer in traditional grouting technology, and significantly improves the grouting effect and enhances the safety of tunnel construction. Compared with the prior art, the present method abandons the reliance on complex and expensive equipment and technology, and can achieve the reinforcement of the sand layer only through simple drilling and grouting steps. In addition, the circulation loop design of the present method allows the discharged slurry to be recycled and reused, which not only reduces the construction cost, but also greatly improves the utilization efficiency of resources.

[0023] The fixed membrane block design in the present invention can effectively block incoming water. According to the size of the sand-rich area, the stop membrane block is adjusted to the optimal position to ensure the accurate injection of slurry during the grouting process, effectively close the potential gap between the flower steel pipe and the grouting hole, and prevent the leakage or loss of slurry during the injection process. This design ensures that the slurry can fully penetrate into the sand-rich layer, avoiding unnecessary waste, thereby greatly improving the efficiency and effect of the grouting operation.

[0024] Advantages of additional aspects of the present invention will be given in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In addition, the spacing or size between the components is exaggerated to show the positions of the components, and the schematic diagram is only used for illustration.

[0026] Figure 1 is a schematic diagram of a grouting method provided in Example 1 of the present invention;

[0027] Figure 2 is a schematic diagram of a grouting system provided in Example 2 of the present invention;

[0028] Figure 3 This is a schematic diagram of a flower steel pipe provided in Example 2 of the present invention;

[0029] In the figure: 1. Grouting hole; 2. Sand discharge hole; 3. Sand-rich area; 4. Flower steel pipe; 5. Sand discharge pipe; 6. Grouting pipe; 7. Horizontal spiral centrifuge; 8. Sand discharge bin; 9. Grouting platform; 10. Grouting membrane block; 11. Grouting hole; 12. Fixed membrane block. DETAILED DESCRIPTION

[0030] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] Example 1

[0032] In order to solve the technical problems mentioned in the background technology, this embodiment proposes a method for replacing the sand layer grouting in a tunnel in a water-rich sand and gravel formation, such as Figure 1 As shown, it includes: drilling a grouting hole 1 and a sand discharge hole 2 on the tunnel face, the grouting hole 1 passes through the middle of the sand-rich area 3, and the sand discharge hole 2 passes through the contour edge of the sand-rich area 3; injecting slurry into the grouting hole 1, the slurry enters the sand-rich area 3, and under the action of pressure, the slurry carries fine sand and squeezes into the sand discharge hole 2 together, and is discharged from the sand discharge hole 2; the discharged slurry and fine sand are separated, and the separated slurry is re-injected into the grouting hole 1; the grouting and sand discharge process is circulated until fine sand is no longer discharged from the sand discharge hole 2.

[0033] The grouting hole 1 passes through the middle of the sand-rich area 3, while the sand-discharging hole 2 passes through the contour edge of the sand-rich area 3, forming a precise replacement area. Specifically, the relative position relationship between the grouting hole 1 and the sand-discharging hole 2 is crucial: the grouting hole 1 is located in the middle of the sand-rich area 3, so that the injected slurry can cover the entire sand-rich area 3, ensuring uniform reinforcement of the sand layer; the sand-discharging hole 2 is located at the edge of the sand-rich area 3, which can smoothly discharge fine sand, thereby ensuring effective diffusion of the slurry.

[0034] During the grouting process, the slurry enters the sand-rich area 3 through the grouting hole 1. Under the action of pressure, the slurry is squeezed into the sand discharge hole 2 together with the fine sand. In this way, not only can the sand particles in the sand-rich layer be effectively replaced, but also the purpose of reinforcement can be achieved. After the slurry and fine sand are separated, the separated slurry will be re-injected into the grouting hole 1 to achieve the recycling of the slurry, improve resource utilization and reduce costs. The entire grouting and sand discharge process will continue until fine sand is no longer discharged from the sand discharge hole 2, which means that the sand-rich layer has been effectively reinforced and replaced.

[0035] A plurality of sand discharge holes 2 are drilled around the grouting hole 1. The plurality of sand discharge holes 2 around the grouting hole 1 discharge fine sand at the same time, forming a plurality of sand discharge channels, thereby improving the smoothness of the replacement process. The plurality of sand discharge holes 2 can increase the sand discharge rate, accelerate the diffusion of the slurry, make the reinforcement of the sand layer more uniform and efficient, avoid the appearance of unreinforced areas in the sand-rich area 3, and increase the stability of the formation. The sand discharge holes 2 are arranged in parallel with the grouting hole 1, located beside the sand-rich layer, and a reasonable spacing is used to ensure effective replacement operation.

[0036] After drilling, high-pressure water jets are used to clean impurities in the grouting hole 1 and the sand discharge hole 2. The high-pressure water jet technology can effectively remove soil, gravel, impurities and other materials in the hole, ensure the patency of the grouting hole 1 and the sand discharge hole 2, avoid the situation of poor slurry injection or incomplete sand discharge due to hole blockage during the grouting process, provide a good channel for slurry injection and fine sand discharge, ensure the smooth grouting and sand discharge, and greatly improve the efficiency and safety of construction.

[0037] Example 2

[0038] This embodiment proposes a grouting system for replacing sand layers in water-rich sand and gravel formation tunnels. Figure 2 As shown, it includes: a grouting platform 9, a steel pipe 4 and a slurry separation device; the steel pipe 4 is installed in the grouting hole 1, the grouting platform 9 is connected to the inlet of the steel pipe 4, the outlet of the sand discharge hole 2 is connected to the slurry separation device, and the slurry discharge outlet of the separation device is connected to the grouting platform 9.

[0039] The flower steel pipe 4 is installed in the grouting hole 1, and its function is to uniformly inject the slurry into the sand-rich area 3 through the slurry outlet holes 11 on the side wall. The grouting platform 9 provides high-pressure slurry and is connected to the inlet of the flower steel pipe 4; the outlet of the sand discharge hole 2 is connected to the slurry separation device, and the separated slurry returns to the grouting platform 9, forming a complete closed-loop system of grouting and fine sand replacement.

[0040] During construction, the grouting platform 9 injects slurry into the grouting hole 1 through a high-pressure pump. The slurry enters the sand-rich area 3 through the slurry outlet hole 11 of the flower steel pipe 4 and is discharged through the sand discharge hole 2 together with the fine sand. The slurry and fine sand mixture enters the slurry separation device. After separation, the slurry is recovered and re-injected into the grouting hole 1. The system achieves efficient reinforcement and replacement of the sand-rich layer through precise grouting and sand discharge control, while ensuring efficient recovery and reuse of the slurry and avoiding waste of resources.

[0041] The grouting platform 9 includes a high-pressure pump and a pressure regulator. The high-pressure pump is used to provide high-pressure slurry, and the pressure regulator adjusts the grouting pressure in real time according to the density of the sand layer. The high-pressure pump is responsible for providing sufficient pressure so that the slurry can penetrate into the sand layer smoothly. The addition of the pressure regulator can dynamically adjust the injection pressure of the slurry according to the real-time formation conditions to ensure that the grouting pressure is always kept within a reasonable range. By accurately controlling the grouting pressure, the formation rupture and waste caused by excessive pressure are avoided, making the grouting operation safer and more effective, and improving the stability of the construction.

[0042] The slurry separation device comprises a horizontal spiral centrifuge 7 and a sand outlet bin 8. The horizontal spiral centrifuge 7 separates fine sand from slurry by utilizing the specific gravity difference between fine sand and slurry. The sand outlet bin 8 is connected to the horizontal spiral centrifuge 7 for storing fine sand.

[0043] The horizontal spiral centrifuge 7 uses the specific gravity difference between fine sand and slurry in the high-speed rotating hub, so that the fine sand first settles on the inner wall of the hub, and is continuously discharged from the hub through the spiral, and enters the sand outlet bin 8, and the slurry is discharged from the overflow port at the other end. The slurry separation device can not only efficiently separate fine sand and slurry, but also effectively recycle the slurry, reducing resource waste, while improving construction efficiency and economy.

[0044] The high-pressure pump is connected to the inlet of the flower steel pipe 4 through a grouting pipe 6, and the outlet of the sand discharge hole 2 is connected to the horizontal spiral centrifuge 7 through a sand discharge pipe 5. The sand discharge pipe 5 is made of wear-resistant material and is suitable for high-concentration fine sand mixtures in the slurry.

[0045] The high-pressure pump on the grouting platform 9 provides the required high-pressure slurry, and transports the slurry to the entrance of the flower steel pipe 4 through the grouting pipe 6. The function of the flower steel pipe 4 is to deliver the slurry to the sand-rich layer and evenly distribute the slurry through its multiple slurry outlet holes 11 to achieve effective reinforcement of the sand layer. The outlet of the sand discharge hole 2 is connected to the horizontal spiral centrifuge 7 through the sand discharge pipe 5. After the slurry and fine sand are discharged through the sand discharge hole 2, they enter the spiral centrifuge through the sand discharge pipe 5 for separation. The slurry separated by the centrifuge flows back to the grouting platform 9 through the pipeline, and the fine sand enters the sand discharge bin 8 for storage. This connection method ensures the efficient transmission and recycling of the slurry. At the same time, the efficient separation of fine sand during the sand discharge process also provides a stable construction environment for subsequent sand layer reinforcement.

[0046] like Figure 3As shown, the flower steel pipe 4 is provided with a slurry outlet hole 11, and the slurry outlet hole 11 has a plurality of holes, and the plurality of slurry outlet holes 11 are provided on the pipe wall of the flower steel pipe 4. Each slurry outlet hole 11 injects slurry into the sand-rich layer at different angles. The design of these slurry outlet holes 11 can ensure the uniform distribution of the slurry, ensuring that all parts of the sand-rich area 3 can be fully covered, thereby improving the grouting effect. The number and arrangement angles of the slurry outlet holes 11 are optimized according to the specific conditions of the sand layer to achieve the best grouting effect. Through the reasonable design of the slurry outlet holes 11, the permeability and reinforcement effect of the slurry in the sand-rich layer can be ensured.

[0047] A sleeve valve is installed in the slurry outlet hole 11. The sleeve valve is a one-way valve. The one-way valve allows the slurry to flow from the inside of the pipe to the outside of the pipe, and cuts off the flow from the outside of the pipe to the inside of the pipe, ensuring that when the slurry is injected into the sand-rich layer, it can fully penetrate into the sand layer around each grouting hole 1, effectively preventing the backflow and pressure loss of the slurry, and improving the efficiency of the grouting process.

[0048] like Figure 3 As shown, a fixed membrane block 12 is provided at the inner end of the flower steel pipe 4, which prevents water from entering the grouting hole 1 and prevents the slurry from flowing out to the top of the flower steel pipe 4. A stop slurry membrane block 10 is installed on the outer wall of the flower steel pipe 4, and the stop slurry membrane block 10 is located at the outer edge of the sand-rich area 3, and is used to close the gap between the flower steel pipe 4 and the grouting hole 1.

[0049] The fixed membrane block 12 is made of flexible waterproof material, which can effectively block the incoming water. According to the size of the sand-rich area 3, the stop slurry membrane block 10 is moved to a suitable position and welded to the flower steel pipe 4. The main function of the stop slurry membrane block 10 is to close the gap between the flower steel pipe 4 and the grouting hole 1 to prevent the slurry from leaking or losing during the injection process. By closing the gap, it ensures that the slurry completely penetrates into the sand-rich layer during the grouting process, and will not be wasted in unnecessary places, thereby improving the efficiency and effect of grouting.

[0050] The grouting process is further explained in combination with the grouting system:

[0051] Step 1: Drilling.

[0052] (1) Arrange grouting holes 1 and sand discharge holes 2 on the tunnel face and select appropriate locations to cover the sand-rich area 3;

[0053] (2) Use high-pressure water jet technology to clean impurities in the hole to ensure that the hole is unobstructed.

[0054] Step 2: Equipment installation.

[0055] Adjust the stop film block 10 on the flower steel pipe 4 so that the closed area formed by the fixed film block 12 corresponds to the sand-rich area 3, and install the flower steel pipe 4 in the grouting hole 1. The grouting platform 9 is connected to the flower steel pipe 4 through the grouting pipe 6, and the sand discharge hole 2 is connected to the sand discharge pipe 5 to the slurry separation device.

[0056] Step 3: Grouting and sand removal operations.

[0057] (1) Initial low-pressure grouting to observe the slurry flow path;

[0058] (2) Pressurization operation is performed to discharge the slurry and fine sand through the sand discharge hole 2.

[0059] Step 4: Slurry separation cycle.

[0060] Fine sand mixed with slurry is transported from the sand discharge pipe 5 to the horizontal spiral centrifuge 7. Under the action of the horizontal spiral centrifuge 7, the fine sand is discharged from the centrifuge to the sand discharge bin 8. The recovered pure slurry is transported to the grouting platform 9 through the other end of the horizontal spiral centrifuge 7 and re-injected into the flower steel pipe 4, forming an efficient slurry recovery and separation circulation system.

[0061] Step 5: Follow-up processing.

[0062] When the fine sand from the separator stops flowing, close the grouting hole 1 and the sand discharge hole 2, clean the equipment and continue with the next stage of construction.

[0063] This method can displace fine sand from the sand discharge hole 2, thereby improving the grouting effect and the safety of tunnel construction. At the same time, since the positions of the grouting holes 1 and the sand discharge holes 2 can be adjusted according to the formation conditions and grouting requirements, this method has wide applicability. The sand discharge circulation loop realizes the secondary use of the discharged sand and slurry, reduces costs, and improves resource utilization. Compared with the traditional grouting reinforcement method, this method does not require the use of complex and expensive equipment and technology. The reinforcement of the sand layer can be achieved through simple drilling and grouting operations.

[0064] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it 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 on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A method for replacing sand layer grouting in a tunnel of water-rich sand and gravel stratum, characterized in that: include: Drilling grouting holes and sand draining holes on the tunnel face, wherein the grouting holes pass through the middle of the sand-rich area, and the sand draining holes pass through the contour edge of the sand-rich area; Inject slurry into the grouting hole, the slurry enters the sand-rich area, and under the action of pressure, the slurry carries fine sand and squeezes into the sand discharge hole, and is discharged from the sand discharge hole; The discharged slurry and fine sand are separated, and the separated slurry is re-injected into the grouting hole; The grouting and sand discharge process is repeated until no more fine sand is discharged from the sand discharge holes.

2. The method for replacing sand layer in a tunnel in a water-rich sand and gravel stratum as claimed in claim 1, characterized in that: A plurality of sand discharge holes are drilled around the grouting hole.

3. The method for replacing sand layer in a tunnel of water-rich sand and gravel stratum according to claim 1, characterized in that: After drilling, use high-pressure water jet to clean impurities in the grouting holes and sand discharge holes.

4. A grouting system using the grouting method for replacing sand layer in a water-rich sand and gravel stratum tunnel according to any one of claims 1 to 3, characterized in that: include: Grouting platform, steel pipe and slurry separation device; The flower steel pipe is installed in the grouting hole, the grouting platform is connected to the inlet of the flower steel pipe, the outlet of the sand discharge hole is connected to the slurry separation device, and the slurry discharge outlet of the separation device is connected to the grouting platform.

5. The grouting system according to claim 4, characterized in that: The grouting platform comprises a high-pressure pump and a pressure regulator. The high-pressure pump is used to provide high-pressure slurry, and the pressure regulator adjusts the grouting pressure in real time according to the density of the sand layer.

6. The grouting system according to claim 5, characterized in that: The slurry separation device comprises a horizontal spiral centrifuge and a sand outlet bin. The horizontal spiral centrifuge separates fine sand from slurry by utilizing the specific gravity difference between fine sand and slurry. The sand outlet bin is connected to the horizontal spiral centrifuge and is used to store fine sand.

7. The grouting system according to claim 6, characterized in that: The high-pressure pump is connected to the inlet of the flower steel pipe through a grouting pipe, and the outlet of the sand discharge hole is connected to the horizontal spiral centrifuge through a sand discharge pipe.

8. The grouting system according to claim 7, characterized in that: The flower steel pipe is provided with a slurry outlet hole, and there are a plurality of the slurry outlet holes, which are arranged on the pipe wall of the flower steel pipe.

9. The grouting system according to claim 8, characterized in that: A sleeve valve is installed in the slurry outlet hole. The sleeve valve is a one-way valve. The one-way valve allows the slurry to flow from the inside of the pipe to the outside of the pipe and cuts off the flow from the outside of the pipe to the inside of the pipe.

10. The grouting system according to claim 8, characterized in that: A fixed membrane block is arranged at the inner end of the flower steel pipe, and a grouting-stopping membrane block is installed on the outer wall of the flower steel pipe. The grouting-stopping membrane block is located at the outer edge of the sand-rich area and is used to close the gap between the flower steel pipe and the grouting hole.

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