Construction method and grouting equipment for shallow hydraulic tunnels crossing rivers in highly permeable strata

Abstract

The present invention relates to the technical field of tunnel construction crossing rivers, specifically, to a construction method and grouting tool for a shallow hydraulic tunnel crossing a river in a highly permeable stratum. The method includes S1, interception and diversion; S2, face reinforcement; S3, tunnel vault reinforcement; S4, tunnel excavation. The grouting tool includes a tool body, the tool body includes a grouting pipe, and the side wall of the grouting pipe is provided with a plurality of grouting holes spaced along the length direction of the grouting pipe; the grouting pipe includes a first grouting part and a second grouting part; the spacing between adjacent grouting holes located at the second grouting part is smaller than the spacing between adjacent grouting holes located at the first grouting part. It can reduce the difficulty and safety risks of underwater operations during construction, and is also beneficial to the operations of construction machinery and personnel in the tunnel, thereby improving construction efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel crossing river construction, in particular to a construction method and grouting tool for a shallow hydraulic tunnel in a highly permeable stratum crossing a river. Background Art

[0002] With the continuous development of water conservancy project construction, hydraulic tunnels, as an important part of water conservancy projects, their construction technology and methods are particularly important, especially in the crossing construction of highly permeable strata or shallow buried hydraulic tunnels; however, the traditional construction method is mainly the mining method; the mining method is suitable for tunnels with good surrounding rock conditions. Through drilling and blasting construction, the drilling and charging layout diagram is determined according to the surrounding rock geological conditions, and then the corresponding support frame support is implemented. However, during the construction of hydraulic tunnels, when the tunnel passes under the river, drilling and blasting construction is likely to cause tunnel collapse, and it is difficult to control the amount of explosives. At the same time, it is difficult to ensure water seepage in the tunnel through support frames; it has a great impact on construction safety and construction progress. Summary of the Invention

[0003] The present invention provides a construction method and grouting tool for a shallow-buried hydraulic tunnel in a highly permeable stratum crossing a river, which can overcome certain defects of the prior art.

[0004] The method for constructing a shallow hydraulic tunnel through a river in a highly permeable stratum according to the present invention comprises the following steps:

[0005] S1, interception and diversion

[0006] When the tunnel reaches the river, a water-blocking wall is built upstream to throttle the flow. Then, two diversion channels are formed along the bottom of the riverbed from upstream to downstream of the tunnel axis. The two diversion channels are located on both sides of the river.

[0007] S2. Tunnel face reinforcement

[0008] After the diversion trough is dug, the diversion trough close to the tunnel construction side is first blocked, and the diversion trough away from the tunnel construction side is dredged. Then, multiple boreholes are drilled at the tunnel face using a drilling machine. First, the first borehole is drilled at the center of the tunnel face. Then, multiple boreholes are drilled circumferentially around the first borehole to form the first grouting ring. Then, the second grouting ring, the third grouting ring, and so on are drilled around the periphery of the first grouting ring until the tunnel face is fully covered with boreholes.

[0009] S3. Tunnel vault reinforcement

[0010] After the tunnel face reinforcement is completed, a drilling machine is used to drill holes along the tunnel extension direction at the top of the tunnel arch. The holes are evenly distributed along the tunnel arch. Then a steel frame is erected inside the tunnel to support the tunnel. After that, the grouting tool is inserted into the grouting holes. The grouting tool includes a grouting pipe with a tapered pusher at the front end and grouting holes on the side wall of the grouting pipe.

[0011] When inserting the grouting tool into the drill hole, wrap hemp silk soaked in CS cement at the end of the drill hole to form a spindle-shaped plunger that is no smaller than the drill hole diameter. Insert the grouting tool into the hole, put on the thread protection cap, and use a pneumatic drill or pneumatic pick to drive the grouting tool to the designed depth. Use the hemp silk plunger to press it against the hole wall, and make sure the tail end of the grouting tool is exposed from the drill hole. Finally, connect the grouting pipe of the grouting machine to the part of the grouting tool exposed from the drill hole, and inject grout into the soil layer through the grouting machine. The grouting penetrates into the soil layer through the grouting tool and fills the soil layer between adjacent drill holes.

[0012] S4. Tunnel Excavation

[0013] After the tunnel vault is reinforced, the reinforced face is excavated by an excavator or manually, with the distance of each tunnel excavation being less than the length of the grouting tooling. Then, steps S2 and S3 are repeated to excavate the tunnel forward. When the tunnel is excavated below the diversion trough on the water side, the diversion trough on the water side of the river channel is blocked and the diversion trough on the other side is dredged. Then, the tunnel is continued to be excavated until the tunnel passes through the river.

[0014] With the present invention, construction workers block the river channel and divert the river water through the diversion trough to pass through the tunnel, so that no water flows above the tunnel construction section, thereby avoiding serious water seepage in the tunnel, reducing the difficulty and safety risks of underwater operations, and also facilitating the operation of construction machinery and personnel in the tunnel, thereby improving construction efficiency.

[0015] By reinforcing the tunnel face, we can effectively prevent it from collapsing due to poor geology or construction disturbance, thus ensuring the safety of construction workers. At the same time, grouting reinforcement can enhance the integrity and stability of the tunnel face rock and soil, and reduce deformation and displacement.

[0016] By setting the drill hole at an angle, when grouting is injected into the drill hole, the slurry seeps out of the drill hole and diverges into the tunnel face, thereby making the grouting in the tunnel face more substantial, thereby better improving the filling effect.

[0017] By reinforcing the top of the tunnel, the top of the tunnel is consolidated by grouting while the construction workers are excavating the face, and the distance of the face excavated each time is less than the length of the tooling. After the face is excavated, it is supported by a steel frame to prevent the top of the tunnel from collapsing when the tunnel is excavated. At the same time, the grouting liquid flows out of the tooling and seeps into the soil layer. The longitudinal overlap length of the tooling is not less than 1.2 meters, the circumferential spacing is 0.4 meters, and the length is 3.2 meters. The soil layer between two adjacent tooling is filled to form a curtain, which isolates the soil layer below the river from seeping into the tunnel.

[0018] Preferably, in step S2, except for the first borehole drilled along the tunnel axis, the remaining boreholes are inclined at an angle of 10-15 degrees to the tunnel axis.

[0019] According to the present invention, the drilling hole is inclined by 10-15 degrees, so that when grouting is injected into the drilling hole, the slurry seeps out of the drilling hole and diverges into the face of the tunnel, thereby making the grouting in the face of the tunnel more substantial, thereby better improving the filling effect.

[0020] Preferably, in step S3, the angle between the drill hole and the tunnel axis is 10-15 degrees.

[0021] Through this embodiment, the borehole is set to be inclined at 10-15 degrees, so that the tooling is also inclined at 10-15 degrees when inserted into the borehole. The inclined tooling can distribute the slurry more evenly, improve the grouting effect, reinforce the stratum, prevent stratum collapse, landslide and other phenomena, and enhance the stability and bearing capacity of the tunnel structure; the inclined setting helps the slurry to better penetrate into the cracks and pores of the stratum, forming an effective anti-leakage barrier, preventing the penetration of groundwater, gas and other substances, and expanding the grouting range.

[0022] Preferably, in step S2, before drilling a hole at the face, the face is drilled by a horizontal drilling rig to drill an exploratory hole, and the geological conditions ahead, such as groundwater, faults, fracture zones, etc., are predicted by changes in the drilling speed of the drilling rig, identification of core samples taken from the borehole, and color, odor, and rock powder of the drilling flushing fluid.

[0023] Through the present invention, the general situation of the rock mass can be intuitively reflected through horizontal drilling, and construction personnel can organize the next step of construction according to the actual geological conditions; secondly, the method can obtain rock cores at a certain distance in front of the working face, so as to judge whether there is groundwater in front and the location of groundwater, providing important geological information for excavation; in addition, horizontal drilling advance detection can also more accurately predict the geological conditions in front of the tunnel, including the stratum interface, rock mass structure, etc., which helps to optimize the construction plan and improve construction safety.

[0024] The present invention provides a grouting tool, including a tool body, the tool body including a grouting pipe, and a plurality of grouting holes arranged at intervals along the length direction of the grouting pipe are provided on the side wall of the grouting pipe; the grouting pipe includes a first grouting part and a second grouting part; the spacing between adjacent grouting holes located at the second grouting part is smaller than the spacing between adjacent grouting holes located at the first grouting part.

[0025] Through the present invention, when installing the tool body, the construction workers first insert the grouting pipe into the drilled hole. During the grouting process into the grouting pipe, the slurry penetrates into the soil layer through the grouting holes. Since the spacing between the grouting holes at the second grouting part is small and the grouting holes are relatively dense, the penetration area of ​​the slurry can be increased during grouting, so that the slurry can more fully contact the stratum or structure, improve the penetration effect, and help to achieve soil layer reinforcement; the spacing between the grouting holes at the first grouting part is large. Since the stratum conditions of the tunnel may vary from top to bottom, the dense grouting holes in the second grouting part can better adapt to complex strata and improve the grouting reinforcement effect; and the sparse grouting hole design of the first grouting part can adjust the grouting amount according to actual needs, thereby realizing the rational use of grouting materials.

[0026] Preferably, the second grouting part is provided with a conical head at one end away from the first grouting part.

[0027] With the present invention, construction workers can knock the grouting pipe when inserting it into the borehole. At this time, the cone head of the grouting pipe is inserted into the soil layer at the bottom of the borehole, thereby facilitating the fixing of the grouting pipe in the borehole and preventing it from falling.

[0028] Preferably, an iron hoop is provided at one end of the first grouting part away from the second grouting part.

[0029] According to the present invention, after the grouting pipe is inserted into the drill hole, the iron hoop is connected to the steel frame by welding, so that the grouting pipe is fixed on the steel frame. When the connection needs to be released, the construction workers only need to knock the iron hoop to knock the iron hoop off the steel frame. The grouting pipe and the steel frame are conveniently connected, and the grouting pipe will not be damaged when the grouting pipe and the steel frame are removed.

[0030] Preferably, the grouting pipe is made of stainless steel.

[0031] Through the present invention, the stainless steel structure has a high strength, which prevents the grouting pipe from being squeezed and deformed by the soil layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the grouting tooling in Example 1. DETAILED DESCRIPTION

[0033] In order to further understand the content of the present invention, the present invention is described in detail with reference to the embodiments. It should be understood that the embodiments are merely for explanation of the present invention and are not intended to limit the present invention.

[0034] Example 1

[0035] This embodiment provides a construction method for a shallow hydraulic tunnel in a highly permeable stratum crossing a river, comprising the following steps:

[0036] S1, interception and diversion

[0037] When the tunnel reaches the river, a water-blocking wall is built upstream to throttle the flow. Then, two diversion channels are formed along the bottom of the riverbed from upstream to downstream of the tunnel axis. The two diversion channels are located on both sides of the river.

[0038] S2. Tunnel face reinforcement

[0039] After the diversion trough is dug, the diversion trough close to the tunnel construction side is first blocked, and the diversion trough away from the tunnel construction side is dredged. Then, multiple boreholes are drilled at the tunnel face using a drilling machine. First, the first borehole is drilled at the center of the tunnel face. Then, multiple boreholes are drilled circumferentially around the first borehole to form the first grouting ring. Then, the second grouting ring, the third grouting ring, and so on are drilled around the periphery of the first grouting ring until the tunnel face is fully covered with boreholes.

[0040] S3. Tunnel vault reinforcement

[0041] After the tunnel face reinforcement is completed, a drilling machine is used to drill holes along the tunnel extension direction at the top of the tunnel arch. The holes are evenly distributed along the tunnel arch. Then, a steel frame is erected in the tunnel to support the tunnel. After that, a grouting tool is inserted into the grouting hole. The grouting tool includes a grouting pipe 160. The front end of the grouting pipe 160 is provided with a conical pusher head 120. The side wall of the grouting pipe 160 is provided with a grouting hole 110.

[0042] When inserting the grouting tool into the drill hole, wrap hemp silk soaked in CS cement at the end of the drill hole to form a spindle-shaped plunger that is no smaller than the drill hole diameter. Insert the grouting tool into the hole, put on the thread protection cap, and use a pneumatic drill or pneumatic pick to drive the grouting tool to the designed depth. Use the hemp silk plunger to press it against the hole wall, and make sure the tail end of the grouting tool is exposed from the drill hole. Finally, connect the grouting pipe of the grouting machine to the part of the grouting tool exposed from the drill hole, and inject grout into the soil layer through the grouting machine. The grouting penetrates into the soil layer through the grouting tool and fills the soil layer between adjacent drill holes.

[0043] S4. Tunnel Excavation

[0044] After the tunnel vault is reinforced, the reinforced face is excavated by an excavator or manually, with the distance of each tunnel excavation being less than the length of the grouting tooling. Then, steps S2 and S3 are repeated to excavate the tunnel forward. When the tunnel is excavated below the diversion trough on the water side, the diversion trough on the water side of the river channel is blocked and the diversion trough on the other side is dredged. Then, the tunnel is continued to be excavated until the tunnel passes through the river.

[0045] Through this embodiment, construction workers block the river channel and divert the river water through the diversion trough, thereby passing through the tunnel. This ensures that no water flows above the tunnel construction section, thereby preventing serious water seepage in the tunnel, reducing the difficulty and safety risks of underwater operations, and facilitating the operation of construction machinery and personnel in the tunnel, thereby improving construction efficiency.

[0046] By reinforcing the tunnel face, we can effectively prevent it from collapsing due to poor geology or construction disturbance, thus ensuring the safety of construction workers. At the same time, grouting reinforcement can enhance the integrity and stability of the tunnel face rock and soil, and reduce deformation and displacement.

[0047] By setting the drill hole at an angle, when grouting is injected into the drill hole, the slurry seeps out of the drill hole and diverges into the tunnel face, thereby making the grouting in the tunnel face more substantial, thereby better improving the filling effect.

[0048] By reinforcing the top of the tunnel, the top of the tunnel is consolidated by grouting while the construction workers are excavating the face, and the distance of the face excavated each time is less than the length of the tooling. After the face is excavated, it is supported by a steel frame to prevent the top of the tunnel from collapsing when the tunnel is excavated. At the same time, the grouting liquid flows out of the tooling and seeps into the soil layer. The longitudinal overlap length of the tooling is not less than 1.2 meters, the circumferential spacing is 0.4 meters, and the length is 3.2 meters. The soil layer between two adjacent tooling is filled to form a curtain, which isolates the soil layer below the river from seeping into the tunnel.

[0049] In this embodiment, in step S2, except for the first borehole drilled along the tunnel axis, the remaining boreholes are inclined at an angle of 10-15 degrees to the tunnel axis.

[0050] Through this embodiment, by setting the drilling hole to be inclined by 10-15 degrees, when grouting is injected into the drilling hole, the slurry seeps out of the drilling hole and diverges into the tunnel face, thereby making the grouting in the tunnel face more substantial, thereby better improving the filling effect.

[0051] In this embodiment, in step S3, the angle between the drill hole and the tunnel axis is 10-15 degrees.

[0052] Through this embodiment, the borehole is set to be inclined at 10-15 degrees, so that the tooling is also inclined at 10-15 degrees when inserted into the borehole. The inclined tooling can distribute the slurry more evenly, improve the grouting effect, reinforce the stratum, prevent stratum collapse, landslide and other phenomena, and enhance the stability and bearing capacity of the tunnel structure; the inclined setting helps the slurry to better penetrate into the cracks and pores of the stratum, forming an effective anti-leakage barrier, preventing the penetration of groundwater, gas and other substances, and expanding the grouting range.

[0053] In this embodiment, in step S2, before drilling a hole in the face, the face is drilled by a horizontal drilling rig to drill an exploratory hole. The geological conditions ahead, such as groundwater, faults, fracture zones, etc., are predicted by changes in the drilling speed of the drilling rig, identification of core samples taken from the borehole, and the color, odor, and rock powder of the drilling flushing fluid.

[0054] Through this embodiment, the general condition of the rock mass can be intuitively reflected through horizontal drilling, and construction personnel can organize the next step of construction according to the actual geological conditions; secondly, this method can obtain rock cores at a certain distance in front of the working face, so as to determine whether there is groundwater in front and the location of groundwater, providing important geological information for excavation; in addition, horizontal drilling advance detection can also more accurately predict the geological conditions in front of the tunnel, including the stratum interface, rock mass structure, etc., which helps to optimize the construction plan and improve construction safety.

[0055] This embodiment provides a grouting tool, including a tool body 100, the tool body 100 includes a grouting pipe 160, and the side wall of the grouting pipe 160 is provided with a plurality of grouting holes 110 arranged at intervals along the length direction of the grouting pipe 160; the grouting pipe 160 includes a first grouting part 140 and a second grouting part 150; the spacing between adjacent grouting holes 110 located at the second grouting part 150 is smaller than the spacing between adjacent grouting holes 110 located at the first grouting part 140.

[0056] Through this embodiment, when installing the tooling body 100, the construction personnel first insert the grouting pipe 160 into the drill hole. During the grouting process into the grouting pipe 160, the slurry penetrates into the soil layer through the grouting holes 110. Since the spacing between the grouting holes 110 at the second grouting part 150 is small and the grouting holes 110 are relatively dense, the penetration area of ​​the slurry can be increased during grouting, so that the slurry can be more fully in contact with the stratum or structure, thereby improving the penetration effect and contributing to the reinforcement of the soil layer. The spacing between the grouting holes 110 at the first grouting part 140 is large. Since the stratum conditions of the tunnel may vary from top to bottom, the dense grouting holes of the second grouting part 150 can better adapt to complex strata and improve the grouting reinforcement effect. The sparse grouting hole design of the first grouting part 140 can adjust the grouting amount according to actual needs to achieve rational use of grouting materials.

[0057] In this embodiment, a cone head 120 having a conical shape is provided at one end of the second grouting part 150 away from the first grouting part 140 .

[0058] Through this embodiment, when construction workers insert the grouting pipe 160 into the borehole, they can knock the grouting pipe 160. At this time, the cone head 120 of the grouting pipe 160 is inserted into the soil layer at the bottom of the borehole, thereby facilitating the fixing of the grouting pipe 160 in the borehole to prevent it from falling.

[0059] In this embodiment, an iron hoop 130 is provided at one end of the first grouting part 140 away from the second grouting part 150 .

[0060] Through this embodiment, after the grouting pipe 160 is inserted into the drilled hole, the iron hoop 130 is connected to the steel frame by welding, so that the grouting pipe 160 is fixed to the steel frame. When the connection needs to be released, the construction personnel only need to knock the iron hoop 130 to knock the iron hoop 130 off the steel frame; it is convenient to connect the grouting pipe 160 and the steel frame, and at the same time, the grouting pipe 160 will not be damaged when the grouting pipe 160 and the steel frame are removed.

[0061] In this embodiment, the grouting pipe 160 is made of stainless steel.

[0062] Through this embodiment, the stainless steel structure is strong enough to prevent the grouting pipe 160 from being squeezed and deformed by the soil layer.

[0063] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application based on one or several embodiments provided in the present application to obtain other embodiments, and these embodiments do not exceed the scope of protection of the present application.

[0064] The above is a schematic description of the present invention and its embodiments, which is not restrictive. The embodiments shown in the embodiments are only part of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the above and, without departing from the purpose of the present invention, designs a structure and embodiment similar to the technical solution without creatively designing, they shall fall within the scope of protection of the present invention.

Claims

1. The construction method of a shallow hydraulic tunnel crossing a river in a highly permeable stratum includes the following steps: S1, interception and diversion When the tunnel reaches the river, a water-blocking wall is built upstream to throttle the flow. Then, two diversion channels are formed along the bottom of the riverbed from upstream to downstream of the tunnel axis. The two diversion channels are located on both sides of the river. S2. Tunnel face reinforcement After the diversion trough is dug, the diversion trough close to the tunnel construction side is first blocked, and the diversion trough away from the tunnel construction side is dredged. Then, multiple boreholes are drilled at the tunnel face using a drilling machine. First, the first borehole is drilled at the center of the tunnel face. Then, multiple boreholes are drilled circumferentially around the first borehole to form the first grouting ring. Then, the second and third grouting rings are drilled around the periphery of the first grouting ring until the tunnel face is fully covered with boreholes. S3. Tunnel vault reinforcement After the tunnel face reinforcement is completed, holes are drilled along the tunnel extension direction by a punching machine at the top of the tunnel arch, and the holes are evenly distributed along the tunnel arch. Then, a steel frame is erected in the tunnel to support the tunnel, and then a grouting tool is inserted into the grouting hole. The grouting tool includes a grouting pipe (160), a pusher head (120) having a conical shape is provided at the front end of the grouting pipe (160), and a plurality of grouting holes (110) are provided at intervals along the length direction of the grouting pipe (160) on the side wall of the grouting pipe (160). The grouting pipe (160) includes a first grouting part (140) and a second grouting part (150). The spacing between adjacent grouting holes (110) located at the second grouting part (150) is smaller than the spacing between adjacent grouting holes (110) located at the first grouting part (140). When inserting the grouting tool into the drill hole, wrap hemp silk soaked in CS cement at the end of the drill hole to form a spindle-shaped plunger that is no smaller than the drill hole diameter. Insert the grouting tool into the hole, put on the thread protection cap, and use a pneumatic drill or pneumatic pick to drive the grouting tool to the designed depth. Use the hemp silk plunger to press it against the hole wall, and make sure the tail end of the grouting tool is exposed from the drill hole. Finally, connect the grouting pipe of the grouting machine to the part of the grouting tool exposed from the drill hole, and inject grout into the soil layer through the grouting machine. The grouting penetrates into the soil layer through the grouting tool and fills the soil layer between adjacent drill holes. S4. Tunnel Excavation After the tunnel vault is reinforced, the reinforced face is excavated by an excavator or manually, with the distance of each tunnel excavation being less than the length of the grouting tooling. Then, steps S2 and S3 are repeated to excavate the tunnel forward. When the tunnel is excavated below the diversion trough on the water side, the diversion trough on the water side of the river channel is blocked and the diversion trough on the other side is dredged. Then, the tunnel is continued to be excavated until the tunnel passes through the river.

2. The method for constructing a shallow hydraulic tunnel through a river in a highly permeable stratum according to claim 1, characterized in that: In step S2, except for the first borehole drilled along the tunnel axis, the remaining boreholes are inclined at an angle of 10-15 degrees to the tunnel axis.

3. The method for constructing a shallow hydraulic tunnel through a river in a highly permeable stratum according to claim 1, characterized in that: In step S3, the angle between the drill hole and the tunnel axis is 10-15 degrees.

4. The method for constructing a shallow hydraulic tunnel through a river in a highly permeable stratum according to claim 1, characterized in that: In step S3, after the tunnel vault is reinforced, anchor holes are drilled at the top of the tunnel, and anchor rods are installed in the anchor holes.

5. The method for constructing a shallow hydraulic tunnel through a river in a highly permeable stratum according to claim 1, characterized in that: In step S2, before drilling the tunnel face, the tunnel face is drilled by a horizontal drilling rig to drill an exploratory hole. The geological conditions ahead are predicted by changes in the drilling speed of the drilling rig, identification of core samples taken from the borehole, color, smell, and rock powder of the drilling fluid.

6. A grouting tool for use in step 3 of the method for constructing a shallow hydraulic tunnel in a highly permeable stratum through a river as claimed in claim 1, characterized in that: The tooling body (100) includes a tooling body (100), and the tooling body (100) includes a grouting pipe (160).

7. A grouting tool according to claim 6, characterized in that: A cone head (120) having a conical shape is provided at one end of the second grouting portion (150) away from the first grouting portion (140).

8. A grouting tool according to claim 7, characterized in that: An iron hoop (130) is provided at one end of the first grouting portion (140) away from the second grouting portion (150).

9. The grouting tool according to claim 7, characterized in that: A sealing section is provided at the first grouting portion (140).

10. The grouting tool according to claim 7, characterized in that: The grouting pipe (160) is made of stainless steel.

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