A composite pipeline system and construction method for long-distance conveying of cement slurry applicable to tunnel curtain grouting

Abstract

The present invention discloses a composite pipeline system and a construction method for long-distance conveying of cement slurry applicable to tunnel curtain grouting, including: a water conveying pipeline, a slurry conveying pipeline, and a compressed air pipeline; wherein: the water conveying pipeline includes a water conveying pipe, and the water conveying pipe is a multi-section rigid pipe body sequentially connected axially, and is used to provide construction water to the excavation face; the slurry conveying pipeline includes a slurry conveying pipe, and the slurry conveying pipe is a multi-section pipe body sequentially connected axially; the slurry conveying pipe is coaxially sleeved inside the water conveying pipe and is used to convey the prepared cement slurry; the compressed air pipeline includes a compressed air pipe, and the compressed air pipe is a multi-section elastic hose axially connected, coaxially sleeved inside the slurry conveying pipe, and the inlet end of the compressed air pipe is used to be connected with the pipeline of the air supply device. By using this composite pipeline system, during the construction of deep and long tunnel curtain grouting, a large amount of slurry can be quickly and in small batches conveyed to the excavation face, avoiding vehicle transportation and manual mixing of slurry in the excavation face area during construction.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel engineering construction and grouting reinforcement, and in particular relates to a composite pipeline system and a construction method for long-distance conveying of cement slurry suitable for tunnel curtain grouting. Background Art

[0002] As China's transportation network continues to extend to the southwestern mountainous areas, the encountered geological conditions are deteriorating continuously. Using the curtain grouting technology to reinforce and improve the stratum has increasingly become an essential link in underground engineering. At the same time, the buried depth and length of tunnels have increased significantly, which has brought huge challenges to the raw material supply of curtain grouting work, especially for tunnel projects with deep vertical shafts.

[0003] In curtain grouting construction, the total amount of grouting in each grouting cycle is large. The longitudinal length of reinforcement in each cycle is about 20 - 30 m, the cross-sectional range of grouting reinforcement is 2 - 5 m outside the excavation contour line, and the volume of the reinforced body is large. According to the different conditions of the stratum itself and the reinforcement requirements, each grouting cycle consumes 300 - 1000 m 3 of slurry. Among them, the most commonly used material is cement slurry, whose price is much lower than other grouting materials. Calculated according to the common water-cement ratio of 1:1, 240 - 800 t of cement is required for each cycle, which is equivalent to 4800 - 16000 bags of cement.

[0004] At the same time, the demand for materials in curtain grouting construction is intermittent and variable, that is, "drilling - grouting - drilling the next hole - grouting...". The grouting volume of different holes is 0.5 - 100 m 3 . After the cement is made into slurry, the setting time is about 6 hours, and the slurry needs to be prepared in small batches in real time. Therefore, when the excavation face is close to the tunnel entrance, within 0.5 km for example, the grouting machine can be arranged on the ground, the slurry can be prepared according to the real-time demand, and then grouting can be carried out at a long distance through the grouting pipe. When the excavation face is far from the tunnel entrance, more than 1 km for example, the grouting machine must be arranged near the excavation face. The cement materials are transported to the vicinity of the excavation face by transport vehicles, and small mixing barrels are used to meet the intermittent and variable real-time slurry demand. This method involves a series of problems such as the loading and unloading of cement materials, temporary stacking in the tunnel, and manual mixing in the tunnel, with low efficiency and large dust. Especially in tunnel projects with deep vertical shafts, the transportation of cement materials will further increase the cost.

[0005] At the same time, when using pipelines to transport slurry to the excavation face over a long distance, there is a contradiction between "transportation speed - pipeline diameter - pipeline loss and residual slurry curing", and it is impossible to meet the slurry supply requirements of "large volume, fast transportation, and small intermittent batches". Summary of the Invention

[0006] The object of the present invention is to provide a composite pipeline system and a construction method for long-distance conveying of cement slurry applicable to tunnel curtain grouting. During the construction of deep tunnel curtain grouting, a large amount of slurry is quickly and in small batches conveyed to the excavation face, avoiding vehicle transportation and manual mixing of slurry in the excavation face area in conventional construction, which can not only effectively improve the grouting construction efficiency but also significantly improve the air environment in the excavation face area.

[0007] The present invention adopts the following technical solutions: A composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting, comprising: a water supply pipeline, a slurry conveying pipeline, and a compressed air pipeline, all having independent inlet ends and outlet ends; wherein:

[0008] The water supply pipeline includes a water supply pipe, which is a multi-section rigid pipe body connected in sequence axially. The water supply pipe is used to supply construction water to the excavation face;

[0009] The slurry conveying pipeline includes a slurry conveying pipe, which is a multi-section pipe body connected in sequence axially; the slurry conveying pipe is coaxially sleeved inside the water supply pipe, forming an annular channel with the water supply pipeline; the inlet end of the slurry conveying pipe is used to be connected to the pipeline of the slurry conveying device, and it is used to convey the prepared cement slurry inside;

[0010] The compressed air pipeline includes a compressed air pipe, which is a multi-section elastic hose connected axially, coaxially sleeved inside the slurry conveying pipe, forming an annular channel with the slurry conveying pipe. The inlet end of the compressed air pipe is used to be connected to the pipeline of the air supply device, and its outlet end is emptied;

[0011] At one end of each section of the elastic hose of the compressed air pipe, a gas control component is provided. The gas control component is used to seal each section of the hose and also used to control the gas flow direction;

[0012] The compressed air pipe is used for: conveying gas inside it, and starting from one section of the elastic hose at the inlet end, sequentially conveying to each section of the elastic hose; and when the gas is conveyed to the hose of the corresponding section, the hose of this section expands and expands outwards, extruding the prepared cement slurry in the annular channel outside this section of the hose, and conveying the cement slurry to the annular channel outside the adjacent next section of the hose, until the prepared cement slurry is conveyed from the outlet end to the excavation face.

[0013] Further, joints are provided at the ends of each section of the hose of the compressed air pipe. The inner cavity of each joint is stepped, and the inner cavity near the hose end is the small-diameter end.

[0014] Further, the gas control component includes an inflation check valve and an exhaust check valve. The inflation check valve and the exhaust check valve are installed side by side at the small-diameter end of the inner cavity of the joints of adjacent two sections of the hose, isolating each section of the hose into an independent and sealed hose chamber.

[0015] Further, the slurry conveying pipe is a weakly elastic hose, which can expand outward in the cross-sectional direction when conveying slurry and contract inward to restore when not conveying slurry.

[0016] Further, the air supply device is a high-pressure gas tank. The inlet of the high-pressure gas tank is connected to an air compressor; the outlet end of the high-pressure gas tank is connected to the inlet of the pressure pipe through a third connecting pipeline. An intake valve is installed on the third connecting pipeline, and a starting air release pipe is vertically connected and communicated with the third connecting pipeline. A starting air release valve is arranged on the starting air release pipe.

[0017] Further, the outlet end of the pressure pipe is communicated with an outlet pipe, and an end air release valve is installed on the outlet pipe.

[0018] Further, the inlet end of the water conveying pipe is connected to a water pump through a first pipeline, and a water inlet valve is arranged on the first pipeline; the outlet end of the water conveying pipe is provided with a water outlet valve.

[0019] Further, the inlet end of the slurry conveying pipe is connected to a slurry pump through a second pipeline, and a slurry inlet valve is installed on the second pipeline; the outlet end of the slurry conveying pipe is connected to a rigid pipe, and a slurry valve is arranged on the rigid steel pipe.

[0020] The present invention also discloses a construction method for the above composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting, and the construction method is as follows:

[0021] Step S11: For grouting one borehole, the water inlet valve 14 and the air intake valve 34 are closed, the water outlet valve 15 is opened, and the water in the water conveying pipeline is emptied; the starting air release valve 35-1 and the end air release valve 35-2 are opened;

[0022] Step S12: The slurry pump, the slurry inlet valve and the slurry outlet valve are opened, and all the slurry is injected into the slurry conveying pipeline;

[0023] Step S13: The slurry pump 22 and the slurry inlet valve are closed, and the slurry outlet valve is opened; the starting air release valve is closed, and the end air release valve is opened;

[0024] The air intake valve is opened, and the compressed air in the high-pressure gas tank enters a section of elastic hose at the inlet end of the pressure pipe from the air intake valve; the air pressure in this section of elastic hose rises, and this section of elastic hose expands until the cross-sectional area is equal to the cross-sectional area of this section of slurry conveying pipe, and all the slurry in the slurry conveying pipe at this place is extruded to the slurry conveying pipe at the adjacent next section of elastic hose;

[0025] Continuously inject compressed air into the elastic hose of this section of the pressure pipe. When the air pressure is greater than the set value, the air enters the adjacent lower-section elastic hose through the inflation check valve. The lower-section elastic hose repeats the expansion process of the upper-section elastic hose, squeezing all the slurry in the slurry delivery pipe at this place to the slurry delivery pipe at the adjacent lower-section elastic hose. When the air pressure in this section of the elastic hose is greater than the set value, the air enters the adjacent lower-section elastic hose through the inflation check valve, and this process is repeated in sequence to complete the extrusion and delivery of the slurry.

[0026] Step S14: Open the starting air release valve, and the air in a section of the elastic hose at the inlet end of the pressure pipe is discharged, and this section of the elastic hose shrinks and returns to its original state. The air in the adjacent lower-section elastic hose is in a high-pressure state. When the air pressure difference with the air in the upper-section elastic hose reaches the set value, the exhaust check valve opens, and the gas in this section of the pressure pipe flows back to the upper-section elastic hose, reducing the air pressure. This continues until all the air in the entire pressure pipe is discharged.

[0027] Step S15: Repeat steps S11 to S14, intermittently deliver the prepared cement slurry to the drill hole until the drill hole reaches the designed grouting.

[0028] Step S16: Clean the slurry delivery pipeline, repeat steps S11 to S15 to complete the grouting of all drill holes.

[0029] Furthermore, before step S11, it also includes drilling. During drilling, the water delivery pipeline injects water into the working face, specifically as follows:

[0030] The slurry inlet valve and the air inlet valve are closed, the slurry outlet valve, the starting air release valve, and the ending air release valve are opened, and the slurry delivery pipe and the pressure pipe are in a contracted state.

[0031] Open the water inlet valve, and the water is transported through the first pipeline to the water delivery pipe, squeezing out the residual air in the slurry delivery pipe and the pressure pipe.

[0032] Open the water outlet valve, and the water flows out from the outlet end of the water delivery pipe and is transported to the drill hole under construction at the working face.

[0033] The beneficial effects of the present invention are as follows: 1. The pressure pipe cooperates with the slurry delivery pipe to intermittently transport the slurry in the slurry delivery pipe to the excavation face, replacing vehicle transportation, and there is no need for loading and unloading, with high efficiency, fast speed, and low cost. 2. Prepare the slurry on the ground outside the tunnel, replacing the preparation of slurry near the excavation face inside the tunnel, and improving the working environment inside the tunnel. Description of the Drawings

[0034] Figure 1 It is a schematic cross-sectional view of a composite pipeline system suitable for long-distance transportation of cement slurry for tunnel curtain grouting;

[0035] Figure 2Schematic diagram of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting;

[0036] Figure 3 Schematic diagram of the connection of pipe sections of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting;

[0037] Figure 4 Schematic diagram of the operation of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting Figure 1 ;

[0038] Figure 5 Schematic diagram of the operation of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting Figure 2 ;

[0039] Figure 6 Schematic diagram of the operation of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting Figure 3 ;

[0040] Figure 7 Schematic diagram of the implementation of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting;

[0041] Among them: 1. Water conveying pipeline; 2. Slurry conveying pipeline; 3. Compressed air pipeline; 4. Slurry storage tank;

[0042] 11. Water storage tank; 12. Water pump; 13. Water conveying pipe; 14. Inlet valve; 15. Outlet valve;

[0043] 21. Slurry mixing station; 22. Slurry conveying pump; 23. Slurry conveying pipe; 24. Inlet slurry valve; 25. Outlet slurry valve;

[0044] 31. High-pressure gas tank; 32. Air compressor; 33. Compressed air pipe; 34. Inlet air valve; 35-1. Starting point air release valve; 35-2. End point air release valve; 36. Inflation check valve; 37. Exhaust check valve. Specific implementation method

[0045] The present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0046] A composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to the present invention, as Figure 1 shown, includes: a water conveying pipeline 1, a slurry conveying pipeline 2, and a compressed air pipeline 3, all of which have independent inlet ends and outlet ends; the length of the slurry conveying pipeline 2 exceeds 2 km, and the pipeline can accommodate about 22.6 m 3 of slurry. If the single slurry conveying volume is less than this value, then there is no slurry flowing out at the outlet slurry valve 25 at this time without external force. Among them:

[0047] The water delivery pipeline 1 includes a water delivery pipe 13, which is composed of multiple rigid pipe bodies connected axially in sequence. The water delivery pipe 13 is used to supply construction water to the excavation face.

[0048] The slurry delivery pipeline 2 includes a slurry delivery pipe 23, which is composed of multiple pipe bodies connected axially in sequence. The slurry delivery pipe 23 is coaxially sleeved inside the water delivery pipe 13, forming an annular channel with the water delivery pipeline 1. The inlet end of the slurry delivery pipe 23 is used to be connected to the pipeline of the slurry conveying device, and it is used to convey the prepared cement slurry inside.

[0049] The air pressure pipeline 3 includes an air pressure pipe 33, which is composed of multiple elastic hoses connected axially. It is coaxially sleeved inside the slurry delivery pipe 23, forming an annular channel with the slurry delivery pipe 23. The inlet end of the air pressure pipe 33 is used to be connected to the pipeline of the air supply device, and its outlet end is emptied.

[0050] At one end of each elastic hose of the air pressure pipe 33, a gas control component is provided. The gas control component is used to seal each hose and also to control the gas flow direction.

[0051] The air pressure pipe 33 is used for: conveying gas inside, and starting from one elastic hose at the inlet end, sequentially conveying to each elastic hose; and when the gas is conveyed to the hose of the corresponding section, the hose of this section expands and expands outwards, squeezing the prepared cement slurry in the annular channel outside this section of the hose, and conveying the cement slurry to the annular channel outside the adjacent next section of the hose, until the prepared cement slurry is conveyed to the excavation face from the outlet end.

[0052] As a specific embodiment, the above-mentioned water delivery pipe 13 adopts multiple sections of seamless steel pipes, and the multiple sections of seamless steel pipes are detachably connected axially in sequence, such as thread connection. Using seamless steel pipes, they serve as the support for the slurry delivery pipe 23 and the air pressure pipe 33. The diameter of the seamless steel pipe can be selected as 150 mm.

[0053] The slurry delivery pipe 23 is a high molecular material hose with weak elasticity and a diameter of 120 mm.

[0054] The above-mentioned air pressure pipe 33 is a high molecular material hose with high elasticity. The diameter in the non-air-pressure contraction state is less than 5 mm, and the diameter in the air-pressure expansion state can exceed 120 mm.

[0055] The lengths of the above-mentioned each section of rigid steel pipe, multiple pipe bodies and each section of elastic hose are equal, such as can be set to 5 m, so that the joints at the corresponding positions are on the same cross-section, facilitating the connection and extension of each pipe.

[0056] At the end of each hose of the above-mentioned air pressure pipe 33, a joint is provided. The inner cavity of each joint is stepped, and the inner cavity near the hose end is the small-diameter end.

[0057] Such as Figure 3As shown in the figure, the above-mentioned gas control component includes an inflation check valve 36 and an exhaust check valve 37. The inflation check valve 36 and the exhaust check valve 37 are installed side by side at the small-diameter end of the inner cavity of adjacent two-section hose connectors, isolating each section of the hose into an independent and enclosed hose chamber.

[0058] The above-mentioned slurry delivery pipe 23 is a weakly elastic hose, which can expand outward in the cross-sectional direction when stressed and contract inward to recover when not stressed.

[0059] As Figure 2 shown, the gas supply device is a high-pressure gas tank 31. The inlet of the high-pressure gas tank 31 is connected to an air compressor 32; the outlet end of the high-pressure gas tank 31 is connected to the inlet of a pressure gas pipe 33 through a third connecting pipeline. An intake valve 34 is installed on the third connecting pipeline, and a starting air release pipe is vertically connected and communicated with the third connecting pipeline. A starting air release valve 35-1 is provided on the starting air release pipe.

[0060] The outlet end of the pressure gas pipe 33 is communicated with an outlet gas pipe, and an end air release valve 35-2 is installed on the outlet gas pipe.

[0061] The inlet end of the water delivery pipe 13 is connected to a water pump through a first pipeline, and a water inlet valve 14 is provided on the first pipeline; the outlet end of the water delivery pipe 13 is provided with a water outlet valve 15.

[0062] The inlet end of the slurry delivery pipe 23 is connected to a slurry delivery pump 22 through a second pipeline, and a slurry inlet valve 24 is installed on the second pipeline; the outlet end of the slurry delivery pipe 23 is connected to a rigid steel pipe, and a slurry valve 25 is provided on the rigid steel pipe.

[0063] The above-mentioned construction method of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting, as Figure 4 、 5 shown in Figures 6 and 7, the construction method is as follows:

[0064] Drill a hole. When drilling, the water delivery pipeline 1 injects water into the working face, specifically as follows:

[0065] Close the slurry inlet valve 24 and the intake valve 34, open the slurry outlet valve 25, the starting air release valve 35-1 and the end air release valve 35-2. The slurry delivery pipe 23 and the pressure gas pipe 33 are in a contracted state;

[0066] Open the water inlet valve 14, and water is conveyed from the first pipeline to the water delivery pipe 13 to squeeze out the residual air in the slurry delivery pipe 23 and the pressure gas pipe 33;

[0067] Open the water outlet valve 15, and water flows out from the outlet end of the water delivery pipe 13 and is conveyed to the drill hole under construction at the working face;

[0068] Step S11: Grout a borehole. Close the water inlet valve 14 and the air inlet valve 34, open the water outlet valve 15, and drain the water in the water delivery pipeline 1. Open the starting point air release valve 35-1 and the ending point air release valve 35-2 to make the pressure air pipe 3 in a contracted state in the cross-sectional direction;

[0069] Turn on the air compressor 32 to fill the high-pressure air tank 31 with compressed air. If the air pressure is between 5 - 8 MPa, as the compressed air is consumed in batches during subsequent operations, turn on the air compressor 32 in real time for replenishment.

[0070] After drilling, perform the following steps:

[0071] Step S11: Grout a borehole. Close the water inlet valve 14 and the air inlet valve 34, open the water outlet valve 15, and drain the water in the water delivery pipeline 1. Open the starting point air release valve 35-1 and the ending point air release valve 35-2 to make the pressure air pipe 3 in a contracted state in the cross-sectional direction;

[0072] Turn on the air compressor 32 to fill the high-pressure air tank 31 with compressed air. If the air pressure is between 5 - 8 MPa, as the compressed air is consumed in batches during subsequent operations, turn on the air compressor 32 in real time for replenishment;

[0073] Step S12: Mix a batch of slurry at the mixing station 21. After the slurry mixing is completed, open the slurry delivery pump 22, the slurry inlet valve 24, and the slurry outlet valve 25, and inject all the slurry into the second pipeline and transport it to the slurry delivery pipe 23. The length of the slurry delivery pipe 23 exceeds 2 km and the diameter reaches 120 mm. The pipeline can accommodate approximately 22.6 m³ of slurry. If the single slurry delivery volume is less than this value, there is no slurry flowing out at the slurry outlet valve 25 at this time.

[0074] Step S13: Close the slurry delivery pump 22 and the slurry inlet valve 24, open the slurry outlet valve 25; close the starting point air release valve 35-1 and open the ending point air release valve 35-2;

[0075] Open the air inlet valve 34, and the compressed air in the high-pressure air tank 31 enters a section of the elastic hose at the inlet end of the pressure air pipe 33 from the air inlet valve 34; the air pressure in this section of the elastic hose rises. When the air pressure rises to 0.1 Mpa, make this section of the elastic hose expand until the cross-sectional area is equal to the cross-sectional area of this section of the slurry delivery pipe 23, and squeeze all the slurry in this section of the slurry delivery pipe 23 to the slurry delivery pipe 23 at the adjacent lower section of the elastic hose;

[0076] Compressed air is continuously injected into the flexible hose of this section of the pressure pipe 3, and the air pressure continuously rises. At this time, limited by the diameter of the slurry delivery pipe 23, and when the air pressure is greater than the set value, such as set to 0.2 MPa, the air enters the adjacent lower-section flexible hose through the inflation check valve 36. The lower-section flexible hose repeats the expansion process of the upper-section flexible hose, squeezing all the slurry in the slurry delivery pipe 23 at this place into the slurry delivery pipe 23 at the adjacent lower-section flexible hose; when the air pressure in this section of the flexible hose is greater than the set value, the air enters the adjacent lower-section flexible hose through the inflation check valve 36, and repeats in turn to complete the extrusion and transportation of the slurry; during this process, the air pressures in the adjacent two sections of hoses are equal, so the exhaust check valve 37 is in a closed state. After completing the extrusion and transportation of the slurry, close the end air release valve 35-2 to stop the gas loss; at the same time, close the air inlet valve 34 to stop the gas injection. At this time, the air pressure in each section of the hose is about 0.2 MPa.

[0077] Step S14: Open the starting point air release valve 35-1, and the air in a section of the flexible hose at the inlet end of the pressure pipe 3 is discharged, and the air pressure decreases until it is 0 MPa, and this section of the flexible hose shrinks and returns to its original state; the air in the adjacent lower-section flexible hose is in a high-pressure state, and when the air pressure difference with the air in the upper-section flexible hose reaches the set value, such as when the pressure difference is greater than 0.05 MPa, the exhaust check valve 37 opens, and the gas in this section of the hose flows back to the upper-section flexible hose, and the air pressure decreases; until the air in the entire pressure pipe 3 is discharged; at the same time, since the expansion pressure of each section of the pressure pipe is 0.1 MPa, which is higher than the passing pressure of the exhaust check valve 37 of 0.05 MPa, so finally under the action of the self-shrinking force of the hose, the air in each section of the hose is completely emptied, and each section of the hose returns to the shrunk state;

[0078] Step S15: Repeat Step S11 to Step S14, and intermittently transport the prepared cement slurry to the drill hole until the drill hole reaches the designed grouting.

[0079] Step S16: Clean the slurry delivery pipeline 2, and repeat Step S11 to Step S15 to complete the grouting of all drill holes.

[0080] The specific process of cleaning the slurry delivery pipeline 2 is as follows:

[0081] Close the slurry inlet valve 24 and the air inlet valve 34, open the slurry outlet valve 25, the starting point air release valve 35-1 and the end air release valve 35-2, so that the slurry delivery pipeline 2 and the pressure pipeline 3 are in a shrunk state;

[0082] Inject clean water in the mixing station to clean the mixing barrel, and then repeat the operation of Step S12, inject the cleaned water into the slurry delivery pipeline for cleaning;

[0083] Open the water inlet valve 14. Under the action of pressure, water fills the water passage in the composite pipeline, further squeezing out the slurry conveying pipeline 2 and the air pressure pipeline 3;

[0084] Use the air pressure pipe 33 to squeeze out the residual water after cleaning from the slurry conveying pipeline; discharge the air in the air pressure pipeline.

Claims

1. A composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting, characterized in that, Including: A water delivery pipeline (1), a slurry delivery pipeline (2) and a compressed air pipeline (3), each having an independent inlet end and an outlet end; wherein: The water delivery pipeline (1) includes a water delivery pipe (13), and the water delivery pipe is a multi-section rigid pipe body connected in sequence axially. The water delivery pipe (13) is used to supply construction water to the excavation face; The slurry delivery pipeline (2) includes a slurry delivery pipe (23), and the slurry delivery pipe (23) is a multi-section pipe body connected in sequence axially; the slurry delivery pipe (23) is coaxially sleeved inside the water delivery pipe (13), forming an annular channel with the water delivery pipeline (1); the inlet end of the slurry delivery pipe (23) is used for pipeline connection with a slurry conveying device, and it is used to convey the prepared cement slurry inside; The compressed air pipeline (3) includes a compressed air pipe (33), and the compressed air pipe (33) is a multi-section elastic hose connected axially, coaxially sleeved inside the slurry delivery pipe (23), forming an annular channel with the slurry delivery pipe (23). The inlet end of the compressed air pipe (33) is used for pipeline connection with an air supply device, and its outlet end is emptied; At one end of each section of the elastic hose of the compressed air pipe (33), a gas control member is provided. The gas control member is used to seal each section of the hose and also used to control the gas flow direction; The compressed air pipe (33) is used for: conveying gas inside, and starting from one section of the elastic hose at the inlet end, sequentially conveying to each section of the elastic hose; and when the gas is conveyed to the hose of the corresponding section, the hose of this section expands and expands outwards, squeezing the prepared cement slurry in the annular channel outside this section of the hose, and conveying the cement slurry to the annular channel outside the adjacent next section of the hose until the prepared cement slurry is conveyed from the outlet end to the excavation face; At the end of each section of the hose of the compressed air pipe (33), a joint is provided. The inner cavity of each joint is stepped, and the inner cavity near the hose end is the small-diameter end; The slurry delivery pipe (23) is a weakly elastic hose, which can expand outwards in the cross-sectional direction when conveying slurry and contract inwards and recover when not conveying slurry.

2. The composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to claim 1, characterized in that, The gas control member includes an inflation check valve (36) and an exhaust check valve (37). The inflation check valve (36) and the exhaust check valve (37) are installed side by side at the small-diameter end of the inner cavity of the joints of adjacent two sections of hoses, isolating each section of the hose into an independent and closed hose chamber.

3. The composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to claim 2, wherein The air supply device is a high-pressure gas tank (31), and the inlet of the high-pressure gas tank (31) is connected to an air compressor (32); the outlet end of the high-pressure gas tank (31) is connected to the inlet of the compressed air pipe (33) through a third connecting pipeline. An inlet valve (34) is installed on the third connecting pipeline. Vertically connected and communicating on the third connecting pipeline is a starting air release pipe, and a starting air release valve (35-1) is provided on the starting air release pipe.

4. The composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to claim 3, wherein, The outlet end of the compressed air pipe (33) is communicated with an outlet pipe, and an end air release valve (35-2) is installed on the outlet pipe.

5. The composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to claim 4, characterized in that, The inlet end of the water delivery pipe (13) is connected to a water pump through a first pipeline, and a water inlet valve (14) is provided on the first pipeline; the outlet end of the water delivery pipe (13) is provided with a water outlet valve (15).

6. The composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to claim 5, characterized in that, The inlet end of the slurry conveying pipe (23) is connected to the slurry conveying pump (22) through a second pipeline, and a slurry inlet valve (24) is installed on the second pipeline; the outlet end of the slurry conveying pipe (23) is connected to a rigid steel pipe, and a slurry valve (25) is arranged on the rigid steel pipe.

7. The construction method of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to any one of claims 1-6, characterized in that, The construction method is as follows: Step S11: For grouting one borehole, the water inlet valve (14) and the air inlet valve (34) are closed, the water outlet valve (15) is opened, and the water in the water conveying pipeline (1) is emptied; the starting point air release valve (35-1) and the ending point air release valve (35-2) are opened; Step S12: The slurry conveying pump (22), the slurry inlet valve (24) and the slurry outlet valve (25) are opened, and all the slurry is injected into the slurry conveying pipeline (2); Step S13: The slurry conveying pump 22 and the slurry inlet valve (24) are closed, and the slurry outlet valve (25) is opened; the starting point air release valve (35-1) is closed, and the ending point air release valve (35-2) is opened; The air inlet valve (34) is opened, and the compressed air in the high-pressure air tank (31) enters an elastic hose at the inlet end of the air pressure pipeline (33) from the air inlet valve (34); the air pressure in this section of elastic hose increases, and this section of elastic hose expands until the cross-sectional area is equal to the cross-sectional area of this section of slurry conveying pipe (23), and all the slurry in the slurry conveying pipe (23) at this place is extruded to the slurry conveying pipe (23) at the adjacent lower section of elastic hose; Compressed air is continuously injected into this section of elastic hose of the air pressure pipeline (33), and when the air pressure is greater than the set value, the air enters the adjacent lower section of elastic hose through the inflation check valve (36), and the lower section of elastic hose repeats the expansion process of the upper section of elastic hose, and all the slurry in the slurry conveying pipe (23) at this place is extruded to the slurry conveying pipe (23) at the adjacent lower section of elastic hose; when the air pressure in this section of elastic hose is greater than the set value, the air enters the adjacent lower section of elastic hose through the inflation check valve (36), and repeats in turn to complete the extrusion and conveying of the slurry; Step S14: The starting point air release valve (35-1) is opened, and the air in an elastic hose at the inlet end of the air pressure pipeline (33) is discharged, and this section of elastic hose contracts and returns to its original state; the air in the adjacent lower section of elastic hose is in a high-pressure state, and when the air pressure difference with the air in the upper section of elastic hose reaches the set value, the exhaust check valve (37) is opened, and the gas in this section of air pressure pipeline flows back to the upper section of elastic hose, and the air pressure decreases; until the air in the entire air pressure pipeline (33) is discharged; Step S15: Repeat Step S11 to Step S14, and intermittently convey the prepared cement slurry to the borehole until the borehole reaches the designed grouting; Step S16: Clean the slurry conveying pipeline (2), and repeat Step S11 to Step S15 to complete the grouting of all boreholes.

8. The construction method of a composite pipeline system for long-distance conveying of cement slurry applicable to tunnel curtain grouting according to claim 7, characterized in that, Before the said Step S11, it also includes drilling, and when drilling, the water conveying pipeline (1) injects water to the working face, specifically as follows: The slurry inlet valve (24) and the air inlet valve (34) are closed, the slurry outlet valve (25), the starting point air release valve (35-1) and the ending point air release valve (35-2) are opened, and the slurry conveying pipe (23) and the air pressure pipeline (33) are in a contracted state; The water inlet valve (14) is opened, and water is transported through the first pipeline to the water delivery pipe (13) to squeeze out the residual air in the slurry delivery pipe (23) and the air pressure pipe (33). The water outlet valve (15) is opened, and water flows out from the outlet end of the water delivery pipe (13) and is transported to the drill hole under construction at the working face.

Images