River-crossing construction method for shallow-buried hydraulic tunnel in strong permeable stratum and grouting tool

Abstract

The invention relates to the technical field of river crossing construction of tunnels, in particular to a river crossing construction method of a shallow-buried hydraulic tunnel in a strong permeable stratum and a grouting tool. The construction method comprises the following steps: S1, intercepting and guiding flow; s2, reinforcing the tunnel face; s3, reinforcing the tunnel vault; and S4, the tunnel is excavated. The grouting tool comprises a tool body, the tool body comprises a grouting pipe, and a plurality of grouting holes formed in the length direction of the grouting pipe at intervals are formed in the side wall of the grouting pipe. The grouting pipe comprises a first grouting part and a second grouting part; the distance between the adjacent grouting holes located in the second grouting part is smaller than the distance between the adjacent grouting holes located in the first grouting part. The difficulty and the safety risk of underwater operation during construction can be reduced, meanwhile, operation of construction machinery and personnel in the tunnel is facilitated, and the construction efficiency is improved.

Description

Technical Field

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

[0002] With the continuous development of water conservancy project construction, hydraulic tunnels are an important part of water conservancy projects, and 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 easy 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 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 or some defects of the prior art.

[0004] The method for constructing a shallow-buried hydraulic tunnel in a highly permeable stratum across a river according to the present invention comprises the following steps: S1, interception and diversion When the tunnel is dug to the river, a water-blocking wall is built upstream of the river to complete the throttling. 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. Face reinforcement After the diversion groove is dug, the diversion groove close to the tunnel construction side is first blocked, and the diversion groove far from the tunnel construction side is dredged, and then multiple boreholes are drilled at the tunnel face by a drilling machine. First, the first borehole is drilled at the center of the tunnel face, and then multiple boreholes are drilled circumferentially along the first borehole to form a first grouting ring, and then the second grouting ring, the third grouting ring, etc. are drilled along the outer periphery of the first grouting ring until the tunnel face is full of boreholes; S3. Tunnel vault reinforcement After the tunnel face reinforcement is completed, a drilling machine is used to drill holes along the extension direction of the tunnel at the top of the tunnel arch. The holes are evenly arranged along the tunnel arch. Then a steel frame is set up in the tunnel to support the tunnel. Then, a grouting tool is inserted into the grouting hole. The grouting tool includes a grouting pipe, a pusher head in a conical shape is provided at the front end of the grouting pipe, and grouting holes are provided at the side wall of the grouting pipe. When the grouting tool is inserted into the borehole, hemp silk with CS glue is wound into a spindle-shaped plunger that is not less than the borehole diameter at the borehole mouth end, the grouting tool is inserted into the hole, the thread protection cap is put on, and the grouting tool is driven into the designed depth with a pneumatic drill or a pneumatic pick, and the hemp silk plunger is pressed against the hole wall, and the tail end of the grouting tool is exposed from the borehole; finally, the grouting pipe of the grouting machine is connected to the part of the grouting tool exposed from the borehole, and grouting is injected 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 boreholes; S4. Tunnel Excavation After the tunnel vault is reinforced, the reinforced face is excavated by an excavator or manually, and the distance of each tunnel excavation is 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.

[0005] Through the present invention, construction workers block the river channel and divert the river water through the diversion groove to pass through the tunnel, so that there is no water flow 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; By reinforcing the tunnel face, it is possible to 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. By setting the drill hole at an angle, when grouting is injected into the drill hole, the slurry seeps out from the drill hole and diffuses into the face of the tunnel, thereby making the grouting in the face of the tunnel more substantial, thereby better improving the filling effect.

[0006] By reinforcing the top of the tunnel, the top of the tunnel is consolidated by grouting while the construction workers are digging 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 prevents water from seeping into the tunnel from the soil layer below the river.

[0007] Preferably, in step S2, except for the first borehole drilled along the axial direction of the tunnel, the remaining boreholes are inclined at an angle of 10-15 degrees to the tunnel axis.

[0008] Through the present invention, the borehole is inclined by 10-15 degrees, so that when grouting is injected into the borehole, the slurry seeps out of the borehole and diffuses into the face of the palm, so that the grouting in the face of the palm is more substantial, thereby preferably improving the filling effect.

[0009] Preferably, in step S3, the angle between the borehole and the tunnel axis is 10-15 degrees.

[0010] Through this embodiment, the borehole is 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.

[0011] 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, and fractured zones, are predicted by changes in the drilling speed of the drilling rig, identification of core sampling, and color, odor, and rock powder of the drilling flushing fluid.

[0012] Through the present invention, the general situation of the rock mass can be intuitively reflected through horizontal drilling, and the construction personnel can organize the next step of construction according to the actual geological conditions; secondly, the method can obtain the rock core at a certain distance in front of the working face, so as to judge whether there is groundwater and the location of groundwater in front, and provide important geological information for excavation; in addition, the 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 is helpful to optimize the construction plan and improve the construction safety.

[0013] The present invention provides a grouting tool, comprising a tool body, the tool body comprising a grouting pipe, a plurality of grouting holes arranged at intervals along the length direction of the grouting pipe are arranged on the side wall of the grouting pipe; the grouting pipe comprises 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.

[0014] Through the present invention, when installing the tooling body, the construction personnel 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 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, the penetration effect is improved, and it is helpful 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, so as to achieve reasonable utilization of grouting materials.

[0015] Preferably, a cone head in a conical shape is provided at one end of the second grouting part away from the first grouting part.

[0016] With the present invention, construction workers can knock the grouting pipe when inserting it into the borehole, and the cone head of the grouting pipe is inserted into the soil layer at the bottom of the borehole, so that the grouting pipe is conveniently fixed in the borehole to prevent it from falling.

[0017] Preferably, an iron hoop is provided at one end of the first grouting part away from the second grouting part.

[0018] 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 personnel 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.

[0019] Preferably, the grouting pipe is made of stainless steel.

[0020] Through the present invention, the stainless steel structure has a relatively high strength, which prevents the grouting pipe from being squeezed and deformed by the soil layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the grouting tooling in Example 1. DETAILED DESCRIPTION

[0022] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0023] Example 1 This embodiment provides a construction method for a shallow-buried hydraulic tunnel in a highly permeable stratum crossing a river, comprising the following steps: S1, interception and diversion When the tunnel is dug to the river, a water-blocking wall is built upstream of the river to complete the throttling. 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. Face reinforcement After the diversion groove is dug, the diversion groove close to the tunnel construction side is first blocked, and the diversion groove far from the tunnel construction side is dredged, and then multiple boreholes are drilled at the tunnel face by a drilling machine. First, the first borehole is drilled at the center of the tunnel face, and then multiple boreholes are drilled circumferentially along the first borehole to form a first grouting ring, and then the second grouting ring, the third grouting ring, etc. are drilled along the outer periphery of the first grouting ring until the tunnel face is full of boreholes; S3. Tunnel vault reinforcement After the tunnel face reinforcement is completed, a drilling machine is used to drill holes along the extension direction of the tunnel at the top of the tunnel arch, and the holes are evenly arranged along the tunnel arch. Then, a steel frame is set up 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 with a conical shape is provided at the front end of the grouting pipe 160, and a grouting hole 110 is provided at the side wall of the grouting pipe 160; When the grouting tool is inserted into the borehole, hemp silk with CS glue is wound into a spindle-shaped plunger that is not less than the borehole diameter at the borehole mouth end, the grouting tool is inserted into the hole, the thread protection cap is put on, and the grouting tool is driven into the designed depth with a pneumatic drill or a pneumatic pick, and the hemp silk plunger is pressed against the hole wall, and the tail end of the grouting tool is exposed from the borehole; finally, the grouting pipe of the grouting machine is connected to the part of the grouting tool exposed from the borehole, and grouting is injected 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 boreholes; S4. Tunnel Excavation After the tunnel vault is reinforced, the reinforced face is excavated by an excavator or manually, and the distance of each tunnel excavation is 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.

[0024] Through this embodiment, the construction workers block the river channel and divert the river water through the diversion groove to pass through the tunnel, so that there is no water flow 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; By reinforcing the tunnel face, it is possible to 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. By setting the drill hole at an angle, when grouting is injected into the drill hole, the slurry seeps out from the drill hole and diffuses into the face of the tunnel, thereby making the grouting in the face of the tunnel more substantial, thereby better improving the filling effect.

[0025] By reinforcing the top of the tunnel, the top of the tunnel is consolidated by grouting while the construction workers are digging 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 prevents water from seeping into the tunnel from the soil layer below the river.

[0026] In this embodiment, in step S2, except for the first borehole drilled along the axial direction of the tunnel, the remaining boreholes are inclined at an angle of 10-15 degrees to the tunnel axis.

[0027] Through this embodiment, by setting the borehole inclined at 10-15 degrees, when grouting is injected into the borehole, the slurry seeps out of the borehole and diffuses into the face of the tunnel, thereby making the grouting in the face of the tunnel more substantial, thereby better improving the filling effect.

[0028] In this embodiment, in step S3, the angle between the borehole and the tunnel axis is 10-15 degrees.

[0029] Through this embodiment, the borehole is 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.

[0030] In this embodiment, in step S2, before drilling a hole at the face, the face is drilled by a horizontal drilling rig to drill an exploration hole, and the geological conditions ahead, such as groundwater, faults, and fractured zones, are predicted through changes in the drilling speed of the drilling rig, identification of core sampling, and color, odor, and rock powder of the drilling flushing fluid.

[0031] Through this embodiment, the general situation of the rock mass can be intuitively reflected through horizontal drilling, and the 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 and the location of groundwater in front, 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 is helpful to optimize the construction plan and improve construction safety.

[0032] The present embodiment provides a grouting tool, including a tool body 100, the tool body 100 includes a grouting pipe 160, and a plurality of grouting holes 110 are arranged 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.

[0033] Through this embodiment, when installing the tooling body 100, the construction personnel first insert the grouting pipe 160 into the drilled 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, the penetration effect is improved, and it is helpful to achieve soil layer reinforcement; 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; and the sparse grouting hole design of the first grouting part 140 can adjust the grouting amount according to actual needs to achieve reasonable utilization of grouting materials.

[0034] 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 .

[0035] 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.

[0036] 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 .

[0037] 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 on 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 the grouting pipe 160 will not be damaged when the grouting pipe 160 and the steel frame are removed.

[0038] In this embodiment, the grouting pipe 160 is made of stainless steel.

[0039] 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.

[0040] It is easy to understand that those skilled in the art can combine, split, reorganize, etc. the embodiments of the present application to obtain other embodiments based on one or several embodiments provided in the present application, and these embodiments do not exceed the protection scope of the present application.

[0041] The present invention and its implementation methods are described schematically above, and the description is not restrictive. The embodiments shown in the embodiments are only part of the implementation methods of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the embodiments and designs a structure and an implementation method similar to the technical solution without creativity without departing from the purpose of the invention, they should all fall within the protection scope of the present invention.

Claims

1. The construction method of a shallow hydraulic tunnel in a highly permeable stratum crossing a river includes the following steps: S1, interception and diversion When the tunnel is dug to the river, a water-blocking wall is built upstream of the river to complete the throttling. 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. Face reinforcement After the diversion groove is dug, the diversion groove close to the tunnel construction side is first blocked, and the diversion groove far from the tunnel construction side is dredged, and then multiple boreholes are drilled at the tunnel face by a drilling machine. First, the first borehole is drilled at the center of the tunnel face, and then multiple boreholes are drilled circumferentially along the first borehole to form a first grouting ring, and then the second grouting ring, the third grouting ring, etc. are drilled along the outer periphery of the first grouting ring until the tunnel face is full of boreholes; S3. Tunnel vault reinforcement After the tunnel face reinforcement is completed, holes are drilled at the top of the tunnel arch along the extension direction of the tunnel by a drilling machine, and the holes are evenly arranged 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 comprises a grouting pipe (160), a pusher head (120) in a conical shape is provided at the front end of the grouting pipe (160), and a grouting hole (110) is provided at the side wall of the grouting pipe (160); When the grouting tool is inserted into the borehole, hemp silk with CS glue is wound into a spindle-shaped plunger that is not less than the borehole diameter at the borehole mouth end, the grouting tool is inserted into the hole, the thread protection cap is put on, and the grouting tool is driven into the designed depth with a pneumatic drill or a pneumatic pick, and the hemp silk plunger is pressed against the hole wall, and the tail end of the grouting tool is exposed from the borehole; finally, the grouting pipe of the grouting machine is connected to the part of the grouting tool exposed from the borehole, and grouting is injected 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 boreholes; S4. Tunnel Excavation After the tunnel vault is reinforced, the reinforced face is excavated by an excavator or manually, and the distance of each tunnel excavation is 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 in a highly permeable stratum across a river according to claim 1, characterized in that: In step S2, except for the first borehole drilled along the axial direction of the tunnel, the remaining boreholes are inclined at an angle of 10-15 degrees to the tunnel axis.

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

4. The method for constructing a shallow hydraulic tunnel in a highly permeable stratum across a river 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 anchors are installed in the anchor holes.

5. The method for constructing a shallow hydraulic tunnel in a highly permeable stratum across a river according to claim 1, characterized in that: In step S2, before drilling holes in the face, the face is drilled by a horizontal drilling rig to drill exploration holes. The geological conditions ahead, such as groundwater, faults, and fracture zones, are predicted through changes in the drilling speed of the drilling rig, identification of core sampling, and color, odor, and rock powder of the drilling flushing fluid.

6. A grouting tool, used in step 3 of the construction method of a shallow hydraulic tunnel in a highly permeable stratum crossing a river, characterized in that: The tooling body (100) comprises a grouting pipe (160), a plurality of grouting holes (110) arranged at intervals along the length direction of the grouting pipe (160) are provided on the side wall of the grouting pipe (160); the grouting pipe (160) comprises a first grouting portion (140) and a second grouting portion (150); the spacing between adjacent grouting holes (110) located at the second grouting portion (150) is smaller than the spacing between adjacent grouting holes (110) located at the first grouting portion (140).

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

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

Images