Dewatering and drainage method for vertical shaft excavation stage

Abstract

The invention discloses a dewatering and drainage method in a vertical shaft excavation stage. The method comprises the following steps: 1, excavating the top of a vertical shaft and performing first-stage drainage; 2, second-stage dewatering and drainage; 3, digging precipitation holes; and 4, third-stage drainage. The dewatering and drainage construction in the vertical shaft excavation process is divided into three stages, the vertical shaft dewatering and drainage work is effectively simplified, working face dry land construction is indeed, and the method is suitable for a vertical shaft with the high water layer content; in the second stage and the third stage, the dewatering and drainage work is rapidly achieved by drilling the drainage holes and the dewatering holes, the number of used sewage pumps is reduced, the dewatering and drainage cost is effectively saved, and therefore the construction quality is guaranteed, the construction cost is saved, and the dewatering and drainage construction efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of vertical shaft construction of water conservancy and hydropower engineering, and in particular relates to a drainage method in a vertical shaft excavation stage. Background Art

[0002] In the existing shaft excavation process, 4-inch sewage pumps are often used to pump water from the excavation surface to the shaft platform. As the shaft is constructed, the shaft depth becomes deeper and deeper, and the amount of water seepage becomes larger and larger. It is necessary to increase the water pump or increase the diameter of the sewage pump and adopt a stepped drainage method to ensure the excavation and support operations of the shaft working surface, which significantly increases the drainage cost. In particular, due to the influence of different geological conditions, in areas with rich groundwater content, the use of sewage pumps for drainage will increase the cost of drainage. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a drainage method in the shaft excavation stage in view of the deficiencies in the above-mentioned prior art. By dividing the drainage construction in the shaft excavation process into three stages, the shaft drainage work is effectively simplified, and the working face is indeed constructed on dry land, which is suitable for shafts with high water content. In the second and third stages, drainage work is quickly achieved by drilling drainage holes and drainage holes, which reduces the number of sewage pumps used and effectively saves drainage costs, thereby ensuring construction quality, saving construction costs, and improving drainage construction efficiency.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a drainage method in the shaft excavation stage, characterized in that the method comprises the following steps: Step 1: Excavation of the top of the shaft and first-stage drainage: The shaft is excavated from the ground downwards. During the excavation process, a sewage pump is set up on the ground to pump out the wastewater generated during the shaft excavation for drainage; Step 2, second stage drainage: During the excavation of the shaft, the slope is excavated on one side of the shaft at the same time. When the slope is excavated to the lowest layer, three drainage holes are drilled obliquely upward in the direction of the shaft using a drilling rig, and the drainage holes extend into the shaft; the three drainage holes are arranged in the same plane, and the ends of the three drainage holes on the slope are connected to sewage pumps; underground seepage between the excavation surface of the shaft and the plane where the three drainage holes are located is discharged to the slope through the three drainage holes; Step 3, digging drainage holes: when the shaft is excavated to the plane where the three drainage holes are located, two drainage holes are drilled downward on the ground using a drilling rig, the two drainage holes are arranged in parallel, and the bottom of the drainage holes is connected to the tunnel; Step 4, third stage drainage: the vertical shaft continues to be excavated downwards until it reaches the designed depth. The wastewater and groundwater generated in the vertical shaft are discharged into the sump of the tunnel through precipitation holes. The water discharged into the sump is discharged into the tertiary sedimentation tank at the tunnel entrance through the multi-stage sump in the tunnel, and then discharged from the tunnel after sedimentation.

[0005] The above-mentioned drainage method in the shaft excavation stage is characterized in that: in step one, the sewage pump is connected to a drainage pipe to discharge the wastewater and groundwater generated during the shaft excavation process.

[0006] The above-mentioned drainage method in the shaft excavation stage is characterized in that: in step 2, the slope range of the drainage hole is 3%~5%.

[0007] The above-mentioned drainage method in the shaft excavation stage is characterized in that: in step 2, a sewage pump is connected to the ends of the three drainage holes, and in the process of discharging underground seepage water, the sewage pump is started to accelerate the discharge of underground seepage water.

[0008] The above-mentioned drainage method in the shaft excavation stage is characterized in that: in step 2 and step 3, the diameter range of the drainage hole and the precipitation hole is 100mm~120mm.

[0009] The above-mentioned drainage method in the shaft excavation stage is characterized in that: in step four, when the waste slag generated during the shaft excavation is discharged out of the well, a sealing steel plate is arranged on the top of the drainage hole to seal the drainage hole; when the shaft excavation is continued subsequently, the sealing steel plate at the hole mouth needs to be removed.

[0010] The above-mentioned drainage method in the shaft excavation stage is characterized in that: in step 4, the shaft excavation and tunnel excavation are carried out simultaneously, and when the tunnel is excavated to the bottom of the shaft, a drainage hole is drilled.

[0011] The beneficial effect of the present invention is that by dividing the dewatering construction in the process of shaft excavation into three stages, the dewatering work of the shaft is effectively simplified, and the working face is constructed on dry land, which is suitable for shafts with high water content; in the second and third stages, the dewatering work is quickly achieved by drilling drainage holes and dewatering holes, which reduces the number of sewage pumps used and effectively saves the dewatering cost, thereby ensuring the construction quality, saving construction costs, and improving the dewatering construction efficiency.

[0012] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the positional relationship among the drainage hole, the vertical shaft and the slope of the present invention.

[0014] Figure 2 It is a schematic diagram of the connection relationship between the drainage hole, the vertical shaft and the tunnel of the present invention.

[0015] Figure 3 The figure is a flowchart of the method of the present invention.

[0016] Description of reference numerals: 1—slope; 2—vertical shaft; 3—drainage hole; 4—drainage hole; 5—tunnel; 6—water collection pit; 7—Third-stage sedimentation tank. DETAILED DESCRIPTION

[0017] like Figure 1 , Figure 2 and Figure 3 A drainage method in a shaft excavation stage is shown, the method comprising the following steps: Step 1: Excavation of the top of the shaft and first-stage drainage: excavation of the shaft 2 is carried out from the ground downwards. During the excavation process, a sewage pump is set on the ground to pump out the wastewater generated during the excavation of the shaft 2 for drainage; Step 2, second stage drainage: During the excavation of the shaft 2, the slope 1 is excavated on one side of the shaft 2 at the same time. When the slope 1 is excavated to the lowest layer, three drainage holes 3 are drilled obliquely upward in the direction of the shaft 2 by using a drilling rig, and the drainage holes 3 extend into the shaft 2; the three drainage holes 3 are arranged in the same plane, and the ends of the three drainage holes 3 on the slope 1 are connected to sewage pumps; underground seepage water between the excavation surface of the shaft 2 and the plane where the three drainage holes 3 are located is discharged to the slope 1 through the three drainage holes 3; Step 3, digging drainage holes: when the shaft 2 is excavated to the plane where the three drainage holes 3 are located, two drainage holes 4 are drilled downward on the ground using a drilling rig, and the two drainage holes 4 are arranged in parallel, and the bottom of the drainage holes 4 is connected to the tunnel 5; Step 4, third stage drainage: the vertical shaft 2 continues to be excavated downward until the vertical shaft 2 is excavated to the designed depth, and the wastewater and underground seepage water generated in the vertical shaft 2 are discharged to the sump 6 of the tunnel 5 through the precipitation holes 4; the water discharged to the sump 6 is discharged to the tertiary sedimentation tank 7 at the entrance of the tunnel 5 through the multi-stage sump 6 in the tunnel 5, and is discharged from the tunnel 5 after sedimentation.

[0018] The present invention divides the drainage construction in the process of excavating the vertical shaft 2 into three stages, thereby effectively simplifying the vertical shaft drainage work, ensuring dry construction on the working surface, and being suitable for vertical shafts with high water content; in the second and third stages, drainage work is quickly achieved by drilling drainage holes 3 and drainage holes 4, reducing the number of sewage pumps used, effectively saving drainage costs, thereby ensuring construction quality, saving construction costs, and improving drainage construction efficiency.

[0019] In the actual construction process of the Class III surrounding rock of the present invention, the Class III surrounding rock is mostly composed of basalt, and the geological conditions are relatively hard. In the process of drilling the drainage holes 3 and the precipitation holes 4, no additional support and reinforcement is required to ensure that the holes do not collapse, so that subsequent drainage is guaranteed. With the elevation of 100 as the dividing line between the second and third stage drainage, when the slope 1 excavated on one side of the shaft 2 is excavated to an elevation of 94 above the elevation of 100, a JDL-300 drilling rig is used to drill three drainage holes 3 with a diameter of 100 mm in the direction of the shaft 2, and the drilling length is about 70 m; when the elevation is below 100, a drilling rig is used to drill two vertical drainage holes with a diameter of 100 mm, and the wastewater and groundwater in the shaft 2 are discharged into the tunnel 5, and then the existing drainage system of the tunnel 5 is used to pump and drain it out of the cave.

[0020] In step 2, since the excavation speed of the slope 1 is greater than the excavation speed of the shaft 2, when the slope 1 is excavated to the lowest layer, the excavation depth of the shaft 2 is higher than the height of the lowest layer of the slope 1. At this time, the three drainage holes 3 drilled can be used to drain the underground seepage water between the excavation surface of the shaft 2 and the plane where the three drainage holes 3 are located.

[0021] In this embodiment, in step 1, the sewage pump is connected to a drainage pipe to discharge the wastewater and underground seepage generated during the excavation of the shaft 2.

[0022] In this embodiment, in step 2, the slope of the drainage hole 3 is in the range of 3% to 5%.

[0023] In this embodiment, in step 2, a sewage pump is connected to the ends of the three drainage holes 3, and in the process of discharging underground seepage water, the sewage pump is started to accelerate the discharge of underground seepage water.

[0024] In actual use, a sewage pump is used to assist the three drainage holes 3 in draining the shaft 2, so as to ensure dry land construction on the working surface during the excavation stage of the shaft 2.

[0025] In this embodiment, in step 2 and step 3, the diameters of the drainage holes 3 and the precipitation holes 4 are both in the range of 100 mm to 120 mm.

[0026] In this embodiment, in step 4, when the waste residue generated during the excavation of the shaft 2 is discharged out of the shaft, a sealing steel plate is arranged on the top of the drainage hole 4 to seal the drainage hole 4; when the shaft 2 is subsequently excavated, the sealing steel plate at the hole mouth needs to be removed.

[0027] In this embodiment, in step 4, the excavation of the shaft 2 and the excavation of the tunnel 5 are carried out simultaneously, and when the tunnel 5 is excavated to the bottom of the shaft 2, the drainage hole 4 is drilled.

[0028] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A drainage method in the shaft excavation stage, characterized in that: The method comprises the following steps: Step 1: excavation of the top of the shaft and first-stage drainage: excavation of the shaft (2) from the ground downwards, during which a sewage pump is set on the ground to pump out the wastewater generated during the excavation of the shaft (2) for drainage; Step 2, second stage drainage: during the excavation of the vertical shaft (2), the slope (1) is excavated on one side of the vertical shaft (2) at the same time. When the slope (1) is excavated to the lowest layer, three drainage holes (3) are drilled obliquely upward in the direction of the vertical shaft (2) by using a drilling rig, and the drainage holes (3) extend into the vertical shaft (2); the three drainage holes (3) are arranged in the same plane, and the ends of the three drainage holes (3) located on the slope (1) are connected to sewage pumps; underground seepage water between the excavation surface of the vertical shaft (2) and the plane where the three drainage holes (3) are located is discharged to the slope (1) through the three drainage holes (3); Step 3, excavating drainage holes: when the vertical shaft (2) is excavated to the plane where the three drainage holes (3) are located, two drainage holes (4) are drilled downward on the ground using a drilling rig, and the two drainage holes (4) are arranged in parallel, and the bottom of the drainage holes (4) is connected to the tunnel (5); Step 4, third stage drainage: the vertical shaft (2) continues to be excavated downward until the vertical shaft (2) is excavated to the designed depth, and the wastewater and underground seepage water generated in the vertical shaft (2) are discharged into the sump (6) of the tunnel (5) through the drainage holes (4); the water discharged into the sump (6) is discharged into the tertiary sedimentation tank (7) at the entrance of the tunnel (5) through the multi-stage sump (6) in the tunnel (5), and is discharged from the tunnel (5) after sedimentation.

2. A drainage method in the shaft excavation stage according to claim 1, characterized in that: In step one, the sewage pump is connected to a drainage pipe to discharge the wastewater and groundwater generated during the excavation of the shaft (2).

3. A drainage method in the shaft excavation stage according to claim 1, characterized in that: In step 2, the slope of the drainage hole (3) is in the range of 3% to 5%.

4. A drainage method in the shaft excavation stage according to claim 1, characterized in that: In step 2, a sewage pump is connected to the ends of the three drainage holes (3), and during the process of draining the underground seepage water, the sewage pump is started to accelerate the drainage of the underground seepage water.

5. A drainage method in the shaft excavation stage according to claim 1, characterized in that: In step 2 and step 3, the diameters of the drainage holes (3) and the precipitation holes (4) are both in the range of 100 mm to 120 mm.

6. A drainage method in the shaft excavation stage according to claim 1, characterized in that: In step 4, when the waste residue generated during the excavation of the vertical shaft (2) is discharged out of the shaft, a sealing steel plate is arranged on the top of the drainage hole (4) to seal the drainage hole (4); when the vertical shaft (2) is subsequently excavated, the sealing steel plate at the hole mouth needs to be removed.

7. A drainage method in the shaft excavation stage according to claim 1, characterized in that: In step 4, the excavation of the vertical shaft (2) and the excavation of the tunnel (5) are carried out simultaneously, and when the tunnel (5) is excavated to the bottom of the vertical shaft (2), a drainage hole (4) is drilled.

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