A method for jacking ultra-deep wells

Abstract

This invention provides a method for ultra-deep shaft jacking construction, comprising the following steps: reinforcing the undisturbed soil within the shaft construction area using MJS high-pressure jet grouting to a first preset depth; installing an anti-pull-out member in the middle of the MJS-reinforced area to a second preset depth; installing a vertical pipe jacking machine in the vertical direction within the shaft construction area, the jacks of the vertical pipe jacking machine lifting and causing the anti-pull-out member to be subjected to upward force in the vertical direction, the tension generated between the anti-pull-out member and the MJS-reinforced area providing the counter-thrust force for the vertical pipe jacking machine; after the vertical pipe jacking machine has jacked downward a preset distance, installing pipe sections on the inner wall of the shaft; dismantling and hoisting out the vertical pipe jacking machine and performing bottom sealing construction. This invention, by reinforcing the soil in the shaft construction area using MJS high-pressure jet grouting, reduces the impact of construction on the surrounding environment, significantly shortens the construction period, and the construction process is simpler and less costly than currently used methods.

Description

Technical Field

[0001] This invention relates to the field of civil engineering construction methods, specifically to a method for jacking construction of ultra-deep wells. Background Technology

[0002] Shaft engineering is one of the major interconnected engineering projects in mine construction. The amount of shaft engineering generally accounts for about 5% of the total amount of mine tunnel engineering, but the construction period accounts for 40% to 50% of the total mine construction period. It has problems such as long construction period. Moreover, at present, the main method of shaft construction in my country is to construct reinforced concrete lining immediately after the shaft excavation face. However, this method of excavating first and then constructing the structure not only has a long construction period and a great impact on the surrounding environment, but also has a high cost. In addition to the above problems, shafts are not only used in non-soft soil areas, but also in some soft soil areas. The environmental control requirements for constructing ultra-deep shafts in these areas are even higher. Summary of the Invention

[0003] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a method for ultra-deep well jacking construction.

[0004] The present invention provides a method for ultra-deep well jacking construction, comprising the following steps:

[0005] The original soil in the well construction area is reinforced by MJS high-pressure jet grouting to form an MJS reinforcement area, which is reinforced to a first preset depth below the design depth of the well.

[0006] In the MJS reinforcement area, an anti-pull-out member is installed to a second preset depth below the design depth of the wellbore, wherein the central axis of the anti-pull-out member coincides with the central axis of the MJS reinforcement area, and the second preset depth is less than the first preset depth.

[0007] A vertical pipe jacking machine is installed in the vertical direction within the shaft construction area. The jacks of the vertical pipe jacking machine stretch and drive the pull-out member to move upward in the vertical direction. The friction between the pull-out member and the MJS reinforced area provides the counter-thrust force for the vertical pipe jacking machine to advance. While the vertical pipe jacking machine is advancing, the cutterhead of the vertical pipe jacking machine continuously cuts the soil around the pull-out member as the central axis to form the shaft.

[0008] After the vertical pipe jacking machine has jacked down a preset distance vertically, pipe sections are installed on the inner wall of the shaft. As the vertical pipe jacking machine continues to jack up, the pipe sections gradually move down under the action of gravity. After the vertical pipe jacking machine moves down another preset distance, pipe sections are installed again. The above steps are repeated until the vertical pipe jacking machine reaches the designed depth of the shaft.

[0009] The vertical pipe jacking machine was dismantled and lifted out, and the bottom sealing construction was carried out.

[0010] Optionally, the way in which the jack of the vertical pipe jacking machine stretches and drives the anti-pull-out component to move vertically upward is as follows: the stretching end of the jack of the vertical pipe jacking machine is connected to a collar through a connector, and the collar is connected to the anti-pull-out component through a locking fastener.

[0011] Optionally, after the vertical jacking has advanced to a preset distance, before the vertical jacking machine moves down another preset distance, the jacks of the vertical jacking machine retract, releasing the locking fasteners, and the collar moves downward to the set position under the pull-out member and is locked by the locking fasteners.

[0012] Optionally, driving pull-out resisting members into the MJS-reinforced area to a second predetermined depth below the wellbore design depth further includes:

[0013] The installation of pull-out resisting components in the MJS-reinforced area to a second predetermined depth below the wellbore design depth further includes:

[0014] In the reinforced area, a pilot hole is made, wherein the central axis of the pilot hole coincides with the central axis of the reinforced area. Through the pilot hole, an anti-pull-out member is driven to a second preset depth below the design depth of the well shaft, and the gap between the anti-pull-out member and the MJS reinforced area is filled with grout.

[0015] Optionally, the vertical pipe jacking machine is lifted out and the bottom sealing construction is carried out, further including:

[0016] The vertical pipe jacking machine is removed from the pull-out-resistant components and then lifted out of the shaft using a crane.

[0017] The pull-out members that exceed the design depth of the well shaft are cut off, and then the bottom of the well shaft is sealed.

[0018] Optionally, when the construction area of ​​the well is soft soil with poor mechanical properties, the MJS reinforcement area covers the entire construction area of ​​the well.

[0019] Optionally, the pull-out member can be a pull-out anchor cable, a pull-out anchor rod, or a pull-out pile.

[0020] Optionally, the first preset depth below the design depth of the wellbore is 10~30m below the design depth of the wellbore.

[0021] Optionally, the second preset depth below the wellbore design depth is 5 to 25 meters below the wellbore design depth.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention provides an ultra-deep shaft jacking construction method. By reinforcing the soil in the shaft construction area with MJS (Mechanical Method for Reinforcing Shafts), the impact of construction on the surrounding environment is reduced. Vertical pipe jacking utilizes the counter-thrust force provided by the pull-out-resistant components. After excavation, precast pipe sections are installed for support to prevent shaft instability and damage. The installation of precast pipe sections replaces the traditional lining method, greatly reducing the construction period. The construction process is simpler and less costly than currently used methods. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 A flowchart of the butterfly-shaped ultra-deep well jacking construction method provided by the present invention;

[0026] Figure 2 This is a cross-sectional view of the well construction area preprocessed according to an embodiment of the present invention;

[0027] Figure 3 This is a cross-sectional view of the pipe jacking operation in an embodiment of the present invention.

[0028] In the diagram: 1. Original soil; 2. MJS reinforced area; 3. Pull-out member; 4. Pipe section; 5. Jack; 6. Connector; 7. Collar; 8. Vertical pipe jacking machine. Detailed Implementation

[0029] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0030] like Figure 1 As shown, the ultra-deep wellbore jacking construction method of the present invention may include the following steps:

[0031] S1, MJS high-pressure jet grouting is used to reinforce the original soil in the well construction area to form an MJS reinforced area, which is reinforced to a first preset depth below the design depth of the well.

[0032] Understandably, when the soil in the construction area is non-soft soil, the range of the MJS reinforcement area can be selected according to the soil conditions. However, when the construction area of ​​the well is soft soil with poor mechanical properties, the MJS reinforcement area covers the entire construction area of ​​the well, thereby effectively reducing the interference to the construction area. Moreover, in order to minimize the interference to the construction area, the first preset depth below the design depth of the well can be designed to be 10~30m below the design depth of the well.

[0033] S2, in the reinforced area of ​​the MJS reinforced area, drive an anti-pull-out member to a second preset depth below the design depth of the well shaft. The second preset depth below the design depth of the well shaft is 5~25m below the design depth of the well shaft, and its depth is between the MJS reinforced depth and the design depth of the well shaft. The central axis of the anti-pull-out member coincides with the central axis of the MJS reinforced area. The second preset depth is less than the first preset depth. The above-mentioned anti-pull-out member can be selected as an anti-pull-out anchor cable, an anti-pull-out anchor rod, or an anti-pull-out pile according to the construction conditions.

[0034] In this embodiment, the MJS-reinforced area is generally cylindrical, similar to the well shaft. Therefore, its central axis is the line connecting the centers of the two end faces of the cylinder. Typically, to facilitate the insertion of the pull-out member, a pilot hole is drilled in the reinforcement area. The central axis of the pilot hole coincides with the central axis of the reinforcement area. The pull-out member is driven through the pilot hole to a second preset depth below the designed depth of the well shaft, and grout is injected into the gap between the pull-out member and the reinforcement area to fill the gap.

[0035] S3, a vertical pipe jacking machine is installed in the vertical direction within the shaft construction area. The jacks of the vertical pipe jacking machine stretch and drive the pull-out member to move upward in the vertical direction. The friction between the pull-out member and the MJS reinforced area provides the counter-thrust force for the vertical pipe jacking machine to advance. While the vertical pipe jacking machine is advancing, the cutterhead of the vertical pipe jacking machine continuously cuts the soil around the pull-out member as the central axis to form the shaft. The cut soil is transported to the ground through the soil removal machine built into the pipe jacking machine.

[0036] For example, in order to facilitate quick assembly and disassembly between the jack and the pull-out member, the way in which the jack of the vertical pipe jacking machine pulls the pull-out member vertically upward is as follows: the pulling end of the jack of the vertical pipe jacking machine is connected to the collar through a connector, and the collar is connected to the pull-out member through a locking fastener.

[0037] S4. After the vertical pipe jacking machine has jacked down a preset distance vertically, where the preset distance is generally not less than the length of the pipe section and can be slightly greater than the length of the pipe section, the pipe section is installed on the inner wall of the shaft. As the vertical pipe jacking machine continues to jack, the pipe section gradually moves down under the action of gravity. After the vertical pipe jacking machine moves down another preset distance, the pipe section is installed again. The above steps are repeated until the vertical pipe jacking machine reaches the designed depth of the shaft. At the same time, after the vertical pipe jacking machine reaches the designed depth of the shaft, the depth formed by the installed pipe section is equal to the designed depth of the shaft. The uppermost pipe section is generally flush with the uppermost surface of the shaft, and the lowermost pipe section is generally flush with the lowermost surface of the shaft.

[0038] Understandably, after the vertical jacking reaches a preset distance, before the vertical pipe jacking machine moves down another preset distance, the jacks of the vertical pipe jacking machine retract, release the locking fasteners, and the collar moves downward to the set position under the pull-out member and is locked by the locking fasteners. In this way, the vertical downward jacking of the vertical pipe jacking machine can be continuously achieved.

[0039] S5, dismantle and lift out the vertical pipe jacking machine and carry out bottom sealing construction.

[0040] For example, lifting out a vertical pipe jacking machine and performing bottom sealing construction further includes:

[0041] The vertical pipe jacking machine is removed from the pull-out-resistant components and then lifted out of the shaft using a crane.

[0042] The pull-out members that exceed the design depth of the well shaft are cut off, and then the bottom of the well shaft is sealed.

[0043] The following is a detailed explanation of the solution in this embodiment:

[0044] (1) such as Figure 2 As shown, with the center of the well construction area as the axis, the original soil within a 5m diameter range is reinforced by high-pressure jet grouting MJS reinforcement, with a reinforcement depth of 60m.

[0045] (2) Use a drilling rig to drill a hole at the center of the MJS reinforcement area 2, then install pull-out anchor rods 3, and then fill the gap between the pull-out anchor rods and the reinforcement soil 2 with grout. The diameter of the pull-out anchor rods 3 is 0.2m and the anchoring depth is 55m.

[0046] (3) such as Figure 2 As shown, the surface soil in the excavation area of ​​the shaft is excavated to -5m, and a vertical pipe jacking machine 8 is installed. The outer diameter of the pipe jacking machine 8 is 10.5m, with the cutterhead facing downwards. With the anti-pull-out anchor 3 as the axis, the pipe jacking jack 5 is connected to the anti-pull-out member 3 through the connector 6 and the collar 7. The collar 7 is equipped with a locking device.

[0047] (4) The jacks 5 on the vertical pipe jacking machine 8 are stretched. The vertical pipe jacking machine 8 obtains a counter-thrust force through the friction between the anti-pull-out anchor 3 and the MJS reinforced area 2, thus pushing downwards. After the vertical pipe jacking machine 8 pushes forward 1.5m, the jacks 5 retract, the locking device on the collar 7 is unlocked, and the position of the collar 7 is adjusted until the connecting piece 6 contacts the jack 6 again. Then, the pipe section 4 is installed behind the vertical pipe jacking machine 8. The inner diameter of the pipe section 4 is 10m, and the length of a single section is 1.5m. After the pipe section 4 is installed, the above operation is repeated until the vertical pipe jacking machine 8 reaches the designed depth of 40m.

[0048] (5) The vertical pipe jacking machine 8 is dismantled and hoisted out of the shaft. The anti-pull anchor rods 3 within a depth of 40m below the ground are cut off and removed. Then the bottom of the shaft is sealed.

[0049] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for jacking ultra-deep wells, characterized in that, Includes the following steps: The original soil in the well construction area is reinforced by MJS high-pressure jet grouting to form an MJS reinforcement area, which is reinforced to a first preset depth below the design depth of the well. In the MJS reinforcement area, an anti-pull-out member is installed to a second preset depth below the design depth of the wellbore, wherein the central axis of the anti-pull-out member coincides with the central axis of the MJS reinforcement area, and the second preset depth is less than the first preset depth. A vertical pipe jacking machine is installed in the vertical direction within the shaft construction area. The jacks of the vertical pipe jacking machine stretch and drive the pull-out member to move upward in the vertical direction. The friction between the pull-out member and the MJS reinforced area provides the counter-thrust force for the vertical pipe jacking machine to advance. While the vertical pipe jacking machine is advancing, the cutterhead of the vertical pipe jacking machine continuously cuts the soil around the pull-out member as the central axis to form the shaft. After the vertical pipe jacking machine has jacked down a preset distance vertically, a pipe section is installed on the inner wall of the shaft. While the vertical pipe jacking machine continues to jack up, the pipe section gradually moves down under the action of gravity. After the vertical pipe jacking machine moves down another preset distance, the pipe section is installed again. The above steps are repeated until the vertical pipe jacking machine reaches the designed depth of the shaft. The vertical pipe jacking machine was dismantled and lifted out, and the bottom sealing construction was carried out.

2. The ultra-deep wellbore jacking construction method according to claim 1, characterized in that: The way in which the jack of the vertical pipe jacking machine stretches and drives the anti-pull-out component to move vertically upward is as follows: the stretching end of the jack of the vertical pipe jacking machine is connected to a collar through a connector, and the collar is connected to the anti-pull-out component through a locking fastener.

3. The ultra-deep well jacking construction method according to claim 2, characterized in that: After the vertical jacking reaches a preset distance, and before the vertical jacking machine moves down another preset distance, the jacks of the vertical jacking machine retract, release the locking fasteners, and the collar moves downward to the anti-pull-out member to a set position and is locked by the locking fasteners.

4. The ultra-deep well jacking construction method according to claim 1, characterized in that: The installation of pull-out resisting components in the MJS reinforced area to a second preset depth below the wellbore design depth further includes: A pilot hole is made in the reinforced area, wherein the central axis of the pilot hole coincides with the central axis of the reinforced area. An anti-pull-out member is driven through the pilot hole to a second preset depth below the designed depth of the well shaft, and the gap between the anti-pull-out member and the MJS reinforced area is filled with grout.

5. The ultra-deep well jacking construction method according to claim 1, characterized in that, The process of lifting the vertical pipe jacking machine out and performing bottom sealing work further includes: The vertical pipe jacking machine is removed from the pull-out resisting member and lifted out of the shaft by a crane; The pull-out members that exceed the design depth of the well shaft are cut off, and then the bottom of the well shaft is sealed.

6. The ultra-deep well jacking construction method according to claim 1, characterized in that, When the construction area of ​​the well shaft is soft soil with poor mechanical properties, the MJS reinforcement area covers the entire construction area of ​​the well shaft.

7. The ultra-deep well jacking construction method according to claim 1, characterized in that, The pull-out resisting component is a pull-out anchor cable, a pull-out anchor rod, or a pull-out pile.

8. The ultra-deep well jacking construction method according to claim 1, characterized in that, The first preset depth below the design depth of the wellbore is 10~30m below the design depth of the wellbore.

9. The ultra-deep well jacking construction method according to claim 1, characterized in that, The second preset depth below the wellbore design depth is 5~25m below the wellbore design depth.

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