Installation technology of immersed tube with large curvature in curved section

Abstract

The present invention relates to the technical field of immersed tube installation, and in particular to an installation process for an immersed tube with a large curvature in a curved section; the process comprises a floating process for the immersed tube and a sinking process for the immersed tube; the floating process for the immersed tube is carried out by seven fully-rotating tugboats, and during the floating process for the immersed tube, the first fully-rotating lifting and towing tugboat and the second fully-rotating lifting and towing tugboat provide power for the advancement and braking of the immersed tube, and the first fully-rotating tugboat, the second fully-rotating tugboat, the third fully-rotating tugboat and the fourth fully-rotating tugboat adjust the position of the axis of the immersed tube through a motor vehicle so that the immersed tube does not deviate from the floating channel; when the immersed tube is floated into place, it is sunk so that the immersed tube is implanted; the installation process for the immersed tube with a large curvature in a curved section of the present invention reduces the number of tugboats required for floating and reduces the cost; the sinking position of the immersed tube is close to the tail end of the installed immersed tube, the distance of pulling together after implantation is small, the offset of the axis of the tail end of the immersed tube is small, and it is conducive to controlling the deviation of the axis of the tail end of the immersed tube.

Description

Technical Field

[0001] The present invention relates to the technical field of immersed tube installation, and in particular to an installation process for an immersed tube with a curved section and large curvature. Background Art

[0002] The installation of large-curvature immersed tubes in curved sections of submarine tunnels is difficult due to the large size and weight of the immersed tubes, the construction technology is difficult, and the control of the installation axis is difficult. The existing floating installation technology for curved section immersed tubes is not fully applicable to the installation of large-curvature immersed tubes in curved sections. Taking the floating installation of the curved section immersed tubes of the Hong Kong-Zhuhai-Macao Bridge as an example, the formation method is as follows: Figure 1 As shown, four high-powered, fully revolving tugboats are used for towing, four for lashing, two for current-resistant work in the base trench, and two for standby. This tugboat formation ensures that the forces applied by each tugboat relative to the axis of the tube are generally symmetrical for sections with shallow curvature. However, for sections with large curvature, the forces applied by each tugboat are asymmetrical relative to the axis, making attitude control difficult during floating. Summary of the Invention

[0003] In response to the deficiencies in the above-mentioned prior art, the present invention provides an installation process for a curved section large curvature immersed tube that can effectively control the posture of the tube segment during floating and the deviation of the axis of the tail end of the immersed tube during sinking.

[0004] The present invention provides an installation process for a large-curvature immersed tube with a curved section, which is characterized by comprising a floating process of the immersed tube and a sinking process of the immersed tube;

[0005] The floating process of the submerged tube is carried out by seven fully rotating tugboats, among which,

[0006] a first fully revolving lifting and towing tug, disposed at the head end of the immersed tube;

[0007] a second fully-rotating lifting and towing tugboat, disposed at the tail end of the immersed tube, the first fully-rotating lifting and towing tugboat and the second fully-rotating lifting and towing tugboat cooperating to provide power for advancing and braking the immersed tube;

[0008] The first and second fully-rotating tugboats are arranged on one side of the immersed tube, and the third and fourth fully-rotating tugboats are arranged on the other side of the immersed tube.

[0009] A spare fully revolving tugboat is provided on one side of the immersed tube;

[0010] During the floating process of the submerged tube, the first fully revolving lifting and towing tugboat and the second fully revolving lifting and towing tugboat provide the power for advancing and braking the submerged tube, and the first fully revolving tugboat, the second fully revolving tugboat, the third fully revolving tugboat and the fourth fully revolving tugboat adjust the axis position of the submerged tube through the motor vehicle so that the submerged tube does not deviate from the floating channel;

[0011] After the submerged tube is floated into position, it is sunk so that the submerged tube is implanted.

[0012] The installation process of the large-curvature immersed tube with curved section of the technical solution reduces the number of tugboats required for floating transportation, reduces the cost, and makes the floating posture of the immersed tube more stable.

[0013] In some embodiments of the present application, the first fully revolvable lifting and towing tugboat and the second fully revolvable lifting and towing tugboat are connected to the mooring posts at the bow and tail ends of the immersed tube using a dragon's beard cable.

[0014] In some embodiments of the application, since the positions of the mooring posts at the head and tail ends of the curved section immersed tube are inconsistent during the floating process of the immersed tube, the dragon beard cable is connected to the mooring posts on both sides of the head / tail end through the first branch rope and the second branch rope respectively, and the first branch rope and the second branch rope are different in length. The intersection of the first branch rope and the second branch rope is located in the forward direction of the immersed tube, so that the floating posture of the curved section large curvature immersed tube is more stable.

[0015] In some embodiments of the present application, the first fully revolving tugboat, the second fully revolving tugboat, the third fully revolving tugboat, and the fourth fully revolving tugboat are all positioned sideways with their bows facing the submerged tube. When the submerged tube rotates, the tugboats in corresponding directions are operated to push the submerged tube forward to achieve on-the-spot turning of the submerged tube. The first fully revolving lifting and tugboat and the second fully revolving lifting and tugboat follow without force to adjust the floating direction of the submerged tube. By adjusting the lengths of both ends of the dragon's beard cable, the force direction of the submerged tube floating is maintained at the axis position of the submerged tube.

[0016] In some embodiments of the present application, when the immersed tube is floated to a certain distance from an installed immersed tube, the immersed tube is moored, and during the mooring process, the first fully revolving lifting and tugboat, the second fully revolving lifting and tugboat, the first fully revolving side tugboat, the second fully revolving side tugboat, the third fully revolving side tugboat, and the fourth fully revolving side tugboat are evacuated in an orderly manner;

[0017] After the mooring is completed, the immersed tube is winched for the first time. When the immersed tube is winched to a distance D1 from the tail end of the installed immersed tube, the immersed tube is prepared for sinking.

[0018] After the sinking preparation work is completed, the immersed tube is twisted and moved for the second time. When the distance from the tail end of the installed immersed tube is D2, the first sinking is carried out.

[0019] When the immersed tube is lowered to the point where the distance between the bottom of its head end and the top of the tail end of the installed immersed tube is S1, adjust the suspension cable at the head end or tail end of the immersed tube so that the longitudinal slope of the immersed tube is consistent with the slope of the gravel bed, and then continue to lower the immersed tube;

[0020] When the immersed tube is lowered to the point where the distance between the bottom of its head end and the top of the gravel bed is S2, the installation cable is retracted in an inch motion, and the immersed tube is twisted and moved to the distance D3 from the tail end of the installed immersed tube, and then the immersed tube is continued to be lowered until it is landed on the gravel bed.

[0021] In some embodiments of the present application, when the immersed tube is floated to a distance of 20m from the installed immersed tube, the immersed tube is moored, and the first fully revolving lifting and towing tugboat, the second fully revolving lifting and towing tugboat, the first fully revolving sideways tugboat, the second fully revolving sideways tugboat, the third fully revolving sideways tugboat, and the fourth fully revolving sideways tugboat are evacuated in an orderly manner.

[0022] In some embodiments of the present application, when the immersed tube is winched to a distance of 10m from the tail end of the installed immersed tube, the immersed tube undergoes sinking preparation operations. The sinking preparation operations include: positioning the diving mother ship, preparing for pipe top sinking, and diving underwater inspection; the pipe top sinking preparation includes: removing some outfitting parts, installing pulling and closing jacks, and installing measuring equipment.

[0023] In some embodiments of the present application, the first sinking is performed when the immersed tube is twisted and moved to a distance of 0.8-1 m from the tail end of the installed immersed tube.

[0024] In some embodiments of the present application, when the immersed tube is lowered to a distance of 0.5 m between the bottom of its head end and the top of the tail end of the installed immersed tube, the suspension cable at the head end or tail end of the immersed tube is adjusted.

[0025] In some embodiments of the present application, when the immersed tube is lowered to a distance of 0.2 m between the bottom of its head end and the top of the gravel base bed, the installation cable is retracted and retracted in an inch motion to move the immersed tube to a distance of 0.6 m from the tail end of the installed immersed tube, and then the immersed tube is continued to be lowered until it is implanted on the gravel base bed.

[0026] Based on the above technical solution, the installation process of the curved section large curvature immersed tube of the present invention reduces the number of tugboats required for floating, reduces costs, and the design of the head and tail towing and dragon beard cable of the immersed tube makes the floating posture of the curved section large curvature immersed tube more stable;

[0027] The sinking position of the immersed tube is close to the tail end of the installed immersed tube. The distance between the twisting and the pulling after implantation during the sinking process is small. The axis offset of the tail end of the immersed tube with large curvature in the curved section is small, which is conducive to controlling the axis deviation of the tail end of the immersed tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0029] Figure 1 Schematic diagram of the floating formation distribution of the curved section immersed tube in the prior art;

[0030] Figure 2 Schematic diagram of the floating formation distribution of the immersed tube with large curvature in the curved section according to an embodiment of the present invention;

[0031] Figure 3 The figure is a flow chart of sinking a curved section immersed tube in the prior art;

[0032] Figure 4 1. This is a flowchart of sinking a large-curvature immersed tube in a curved section according to an embodiment of the present invention;

[0033] Figure 5 This is a diagram showing the cable arrangement for a large-curvature immersed tube in a curved section according to an embodiment of the present invention;

[0034] 10. Submerged tube; 20. First fully revolving lifting and towing tug; 30. Second fully revolving lifting and towing tug; 40. First fully revolving side tug; 50. Second fully revolving side tug; 60. Third fully revolving side tug; 70. Fourth fully revolving side tug; 80. Spare fully revolving tug. DETAILED DESCRIPTION

[0035] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0036] In the description of the present invention, it should be understood that the terms "center", "transverse", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0037] The terms "first," "second," and "third" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or to implicitly specify the quantity of the technical features indicated. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include one or more of such features.

[0038] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0039] The existing installation of curved immersed tube segments requires many tugboats for floating. Figure 1 The figure shows the floating formation for the Hong Kong-Zhuhai-Macao Bridge's curved section immersed tubes. It employs four high-powered, fully revolving tugboats for towing, four fully revolving tugboats for lashing, two tugboats for current-resistant work in the foundation trench, and two tugboats in standby. This floating method ensures that the forces applied by each tugboat are essentially symmetrical relative to the axis of the immersed tube for curved sections with less curvature. However, for curved sections with greater curvature, the forces applied by each tugboat are asymmetrical relative to the axis, making posture control difficult during the floating process. Furthermore, the original floating formation for the Hong Kong-Zhuhai-Macao Bridge required a total of 12 tugboats to participate in the operation, resulting in high costs. Existing floating methods are not suitable for the floating of heavily curved immersed tubes.

[0040] like Figure 2 As shown, the floating process of the immersed tube in this embodiment is carried out by seven fully rotating tugboats. The immersed tube 10 is a curved section with a large curvature, and its curvature radius is 1050m and the arc length is 148m.

[0041] A first fully revolving towing tugboat 20 is provided at the head end of the immersed tube 10;

[0042] The second fully revolving towing tugboat 30 is disposed at the rear end of the immersed tube 10. The first fully revolving towing tugboat 20 and the second fully revolving towing tugboat 30 cooperate to provide power for the advancement and braking of the immersed tube 20.

[0043] The first and second fully revolvable tugboats 40 and 50 are arranged on the outer side of the immersed tube 10, and the third and fourth fully revolvable tugboats 60 and 70 are arranged on the inner side of the immersed tube 10.

[0044] A spare fully revolving tugboat 80 is provided on one side of the immersed tube 10. In this embodiment, it is provided on the inner side of the immersed tube 10. When a fully revolving towing tugboat or a side-towing tugboat fails, the spare fully revolving tugboat 80 can take over its work to avoid delays in the construction period.

[0045] During the floating process of the immersed tube 10, the first and second tugboats 20 and 30 provide the power for the advancement and braking of the immersed tube, while the first, second, third, and fourth tugboats 40, 50, 60, and 70 use motor vehicles to adjust the axis position of the immersed tube 10 so that it does not deviate from the floating channel.

[0046] After the submerged tube 10 is floated to its place, it is sunk so that it is implanted in the bed.

[0047] The installation process of the large-curvature immersed tube with curved section of the technical solution reduces the number of tugboats required for floating transportation, reduces the cost, and makes the floating posture of the immersed tube more stable.

[0048] like Figure 2 As shown, the first fully revolving lifting and towing tugboat 20 and the second fully revolving lifting and towing tugboat 30 are connected to the mooring posts at the head and tail ends of the immersed tube 10 respectively using dragon beard cables. Since the mooring posts at the head and tail ends of the immersed tube 10 are not in the same position during the floating process of the curved section immersed tube, the first fully revolving lifting and towing tugboat 20 is connected to the mooring posts at both ends of the head end of the immersed tube 10 using the first branch rope and the second branch rope of the dragon beard cable, and the second fully revolving lifting and towing tugboat 30 is connected to the mooring posts at both ends of the tail end of the immersed tube 10 using the first branch rope and the second branch rope of the dragon beard cable. Figure 1 It can be seen that the length of the first branch rope is greater than that of the second branch rope, and the intersection of the first branch rope and the second branch rope is located in the forward direction of the immersed tube 10, making the floating posture of the immersed tube with large curvature in the curved section more stable.

[0049] The first fully revolvable tugboat 40, the second fully revolvable tugboat 50, the third fully revolvable tugboat 60 and the fourth fully revolvable tugboat 70 are all positioned sideways with their bows facing the submerged tube 10. When the submerged tube 10 rotates, the tugboats in the corresponding directions are operated to push the submerged tube forward to achieve on-site turning of the submerged tube 10. The first fully revolvable lifting and tugboat 10 and the second fully revolvable lifting and tugboat 20 follow without force to adjust the floating direction of the submerged tube 10. By adjusting the length of the first branch rope and the second branch rope of the dragon's beard cable, the force direction of the floating of the submerged tube 10 is maintained at the position of the axis of the submerged tube.

[0050] After the immersed tube is transported to its place, it needs to be sunk. The sinking process of the E10 section of the Hong Kong-Zhuhai-Macao Bridge curved section is as shown in the attached figure. Figure 3As shown, the immersed tube is prepared for placement at a location 40 meters from the end of the installed tube. After preparations are complete, the tube is twisted to a location 5 meters from the butt joint for placement. The first tube is lowered to 2 meters from the subgrade, where the longitudinal slope of the tube is adjusted. The second tube is lowered to 0.8 meters from the end of the installed tube until it is planted. The twisting and closing direction of the immersed tube in the curved section is perpendicular to the tube's head and out of alignment with the tube's axis. This causes the axis of the tube's end to deviate during the twisting and closing process, with the greater the curvature, the greater the deviation. Therefore, during the immersed tube installation process in the Hong Kong-Zhuhai-Macao Bridge curved section, the twisting distance and the required closing distance after placement are long. Due to the small curvature, the axis deviation at the end of the tube is negligible. However, during the installation of the curved tube sections with large curvatures, the axis deviation at the end of the tube is significant, making it difficult to control. Therefore, the existing immersed tube installation process for the Hong Kong-Zhuhai-Macao Bridge is not suitable for installation of immersed tubes in curved sections with large curvatures.

[0051] In this embodiment, when the immersed tube 10 is floated to a distance of 20m from the installed immersed tube, the immersed tube 10 is moored. During the mooring process, the first fully revolving lifting and tugging tugboat, the second fully revolving lifting and tugging tugboat, the first fully revolving sideways tugboat, the second fully revolving sideways tugboat, the third fully revolving sideways tugboat, and the fourth fully revolving sideways tugboat are evacuated in an orderly manner; according to the on-site construction environment, if it is located in a wide sea area, after the immersed tube is floated into place, the four mooring lines at the bow and stern are moored first. After the four mooring lines are moored, the position of the ship tube can be stabilized by the four mooring lines, and all tugboats are evacuated together.

[0052] After mooring is completed, the immersed tube 10 is winched for the first time. When the immersed tube 10 is winched to a distance D1 of 10m from the tail end of the installed immersed tube, the immersed tube is prepared for sinking. The sinking preparation includes: positioning the diving mother ship, preparing for sinking the tube top, and diving underwater inspection. The sinking preparation includes: removing some outfitting parts, installing the pulling jack, and installing measuring equipment.

[0053] After the sinking preparation work is completed, the immersed tube 10 is twisted and moved for the second time. When the distance D2 from the tail end of the installed immersed tube is 0.8-1.0m, the first sinking is carried out.

[0054] When the immersed tube 10 is lowered to the point where the distance S1 between the bottom of its head end and the top of the installed tail end of the immersed tube is 0.5 m, adjust the suspension cable at the head end or tail end of the immersed tube 10 so that the longitudinal slope of the immersed tube is consistent with the slope of the gravel bed, and then perform the second sinking to continue lowering the immersed tube 10;

[0055] When the immersed tube is lowered to a distance S2 of 0.2m between its head end and the designed elevation of the top of the gravel bed, the longitudinal slope of the immersed tube is adjusted. The bottom of the immersed tube is parallel to the bed, and the height difference between the bottom of the immersed tube and the bed is the same at all locations. The H installation cable is retracted and inched, and the immersed tube 10 is twisted and moved for a third time. After twisting it to a position D3 0.6m from the tail end of the installed immersed tube, it is lowered for a third time and the immersed tube 10 is lowered again until it touches the gravel bed. After the immersed tube is installed and placed, the distance between it and the installed immersed tube is small, and the axis offset of the tail end of the immersed tube with large curvature is small, which helps to control the deviation of the axis of the tail end of the immersed tube.

[0056] like Figure 5 As shown, there are three types of cables in the ship pipe: mooring cable, hoisting cable, and installation cable. The mooring cable controls the position of the installation vessel, the hoisting cable controls the lowering of the immersed tube, and the installation cable controls the position of the immersed tube. During the lowering of the immersed tube, both the mooring cable and the installation cable have cable force control requirements to prevent the ship pipe from becoming unstable. If the plane position of the immersed tube deviates too much during the sinking process, the installation cable needs to be used for adjustment.

[0057] The installation process of the curved section high curvature immersed tube of the present invention reduces the number of tugboats required for floating, thus reducing costs. The design of the head and tail towing and dragon beard cable of the immersed tube makes the floating posture of the curved section high curvature immersed tube more stable.

[0058] The sinking position of the immersed tube is close to the tail end of the installed immersed tube. The distance between the twisting and the pulling after implantation during the sinking process is small. The axis offset of the tail end of the immersed tube with large curvature in the curved section is small, which is conducive to controlling the axis deviation of the tail end of the immersed tube.

[0059] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0060] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the same. Although the present invention has been described in detail with reference to preferred embodiments, persons skilled in the art should understand that the specific implementation methods of the present invention may still be modified or some technical features may be replaced by equivalents without departing from the spirit of the technical solutions of the present invention, and all of these should fall within the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A process for installing a large-curvature immersed tube in a curved section, characterized by: Including the process of floating and placing the submerged tube; The floating process of the submerged tube is carried out by seven fully rotating tugboats, among which, a first fully revolving lifting and towing tug, disposed at the head end of the immersed tube; a second fully revolving lifting and towing tug, disposed at the tail end of the immersed tube; The first and second fully-rotating tugboats are arranged on one side of the immersed tube, and the third and fourth fully-rotating tugboats are arranged on the other side of the immersed tube. A spare fully revolving tugboat is provided on one side of the immersed tube; During the floating process of the submerged tube, the first fully revolving lifting and towing tugboat and the second fully revolving lifting and towing tugboat provide the power for advancing and braking the submerged tube, and the first fully revolving tugboat, the second fully revolving tugboat, the third fully revolving tugboat and the fourth fully revolving tugboat adjust the axis position of the submerged tube through the motor vehicle so that the submerged tube does not deviate from the floating channel; After the submerged tube is floated into position, it is sunk so that the submerged tube is placed on the bed; When the immersed tube is floated to a certain distance from the installed immersed tube, the immersed tube is moored, and during the mooring process, the first fully revolving lifting and towing tugboat, the second fully revolving lifting and towing tugboat, the first fully revolving side tugboat, the second fully revolving side tugboat, the third fully revolving side tugboat, and the fourth fully revolving side tugboat are evacuated in an orderly manner; After the mooring is completed, the immersed tube is winched for the first time. When the immersed tube is winched to a distance D1 from the tail end of the installed immersed tube, the immersed tube is prepared for sinking. After the sinking preparation work is completed, the immersed tube is twisted and moved for the second time. When the distance from the tail end of the installed immersed tube is 0.8-1m, the first sinking is carried out. When the immersed tube is lowered to the point where the distance between the bottom of its head end and the top of the installed tail end of the immersed tube is 0.5 m, adjust the suspension cable at the head end or tail end of the immersed tube so that the longitudinal slope of the immersed tube is consistent with the slope of the gravel bed, and then continue to lower the immersed tube; When the immersed tube is lowered to a distance of 0.2m between the bottom of its head end and the top of the gravel base bed, the installation cable is retracted and released by inch, and the immersed tube is twisted and moved to a distance of 0.6m from the tail end of the installed immersed tube, and then the immersed tube is continued to be lowered until it is landed on the gravel base bed.

2. The installation process of the curved section large curvature immersed tube according to claim 1 is characterized in that: The first fully revolving lifting and towing tugboat and the second fully revolving lifting and towing tugboat are connected to the mooring posts at the bow and tail ends of the immersed tube using dragon beard cables.

3. The installation process of the curved section large curvature immersed tube according to claim 2 is characterized in that: The dragon beard cable is connected to the mooring posts on both sides of the head / tail end through the first branch rope and the second branch rope respectively, and the first branch rope and the second branch rope have different lengths. The intersection of the first branch rope and the second branch rope is located in the forward direction of the immersed tube.

4. The installation process of the curved section large curvature immersed tube according to claim 2 is characterized in that: The first fully revolving tugboat, the second fully revolving tugboat, the third fully revolving tugboat and the fourth fully revolving tugboat are all positioned sideways with their bows facing the submerged tube. When the submerged tube rotates, the tugboats in the corresponding directions are operated to push the submerged tube forward to achieve on-site turning of the submerged tube. The first fully revolving lifting and tugboat and the second fully revolving lifting and tugboat follow without force to adjust the floating direction of the submerged tube. By adjusting the length of both ends of the dragon's beard cable, the force direction of the submerged tube floating is maintained at the axis position of the submerged tube.

5. The installation process of the curved section large curvature immersed tube according to claim 4 is characterized in that: When the submerged tube is floated to a distance of 20m from the installed submerged tube, the submerged tube is moored, and the first fully revolving lifting and towing tugboat, the second fully revolving lifting and towing tugboat, the first fully revolving sideways tugboat, the second fully revolving sideways tugboat, the third fully revolving sideways tugboat and the fourth fully revolving sideways tugboat are evacuated in an orderly manner.

6. The installation process of the curved section large curvature immersed tube according to claim 5 is characterized in that: When the immersed tube is winched to a distance of 10m from the tail end of the installed immersed tube, the immersed tube is prepared for sinking. The sinking preparation work includes: positioning the diving mother ship, preparing for sinking the pipe top, and diving underwater inspection; the preparation for sinking the pipe top includes: removing some outfitting parts, installing the pulling and closing jacks, and installing measuring equipment.

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