A method for controlling the tail end axis of a curved section immersed tube installation

Abstract

The present invention is a method for controlling the axis of the tail end of a immersed tube installation in a curved section, and the specific steps are: mooring completion; first twisting and shifting of the pipe segment; preparation for sinking; second twisting and shifting of the pipe segment; first lowering of the pipe segment, where the immersed tube is lowered for the first time at a position 0.8m-1m away from the butt end to a height of 10.2m from the designed top elevation of the subgrade; adjusting the longitudinal slope by adjusting the four L cables hoisted on the top of the immersed tube so that the longitudinal wave of the immersed tube is consistent with the slope of the gravel subgrade; second lowering of the pipe segment to a height of 0.2m from the bottom end of the immersed tube to the designed top elevation of the subgrade; third twisting and shifting of the pipe segment; third lowering of the pipe segment to the designed bottom elevation; placement of the pipe segment; pulling and closing the butt joint; hydraulic pressing. The placement position of the pipe segment of the present invention is close to the installed pipe segment, the pulling and closing distance after the immersed tube is placed is small, and the offset of the axis of the tail end of the immersed tube in the curved section is small; controlling the position of the axis of the tail end of the pipe segment by controlling the installation cable of the tail end of the pipe segment is beneficial to controlling the deviation of the axis of the tail end of the immersed tube installation in the curved section.

Description

Technical Field

[0001] The present invention relates to the technical field of submarine tunnel construction, and in particular to a method for controlling the tail end axis of a curved section immersed tube during installation. Background Art

[0002] During submarine tunnel construction, the construction of immersed tubes in curved sections is technically challenging, and controlling the axis at the tail end is particularly challenging. For example, in the Dalian Bay Subsea Tunnel project, which boasts the highest curvature among existing immersed tube tunnels in China, the direction of closing and folding the immersed tubes in the curved section is perpendicular to the tube's head end, which is inconsistent with the axis of the tube. This causes the axis of the tail end of the tube to deviate during the closing and folding process, making the installation process for immersed tubes in straight sections unsuitable for those in curved sections, thus affecting the quality of the final installation. Summary of the Invention

[0003] The present invention aims to solve the deficiencies of the prior art and provides a method for controlling the axis of the tail end of a curved section immersed tube installation.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical solutions:

[0005] A method for controlling the axis of the tail end of a curved section immersed tube installation, comprising the following specific steps:

[0006] S1. Mooring completed

[0007] The installation vessel is moored 20m away from the docking end;

[0008] S2, the first twisting of the pipe segment

[0009] Inch-move the installation cable to move the pipe joint to a position 10m away from the butt end;

[0010] The installation cables include four H cables and eight M cables. The H cables are connected by a winch on the installation vessel from the fairlead on the pipe segment to the pre-dropped anchor on the seabed to control the horizontal position of the pipe segment. The M cables are connected by a winch on the installation vessel from the fairlead on the installation vessel to the pre-dropped anchor on the seabed to control the horizontal position of the installation vessel.

[0011] S3. Preparation for sinking

[0012] Check each working part and make preparations for sinking;

[0013] S4, the second twisting of the pipe segment

[0014] Inch-move the retractable installation cable to twist the pipe joint to a position 0.8-1m away from the butt end;

[0015] S5, the first lowering of the pipe segment

[0016] The immersed tube is lowered for the first time at a position 0.8m-1m away from the butt end, and is lowered to a height of 10.2m from the designed top elevation of the subgrade.

[0017] S6. Adjust the longitudinal slope

[0018] By adjusting the four L cables hoisted on the top of the immersed tube, the longitudinal wave of the immersed tube is made consistent with the slope of the gravel bed;

[0019] S7, the second lowering of the pipe section

[0020] The second time, the bottom of the immersed tube is lowered to a height of 0.2m from the top of the subgrade;

[0021] S8, the third twisting of the pipe segment

[0022] Inch-move the installation cable to move the pipe joint to a position 0.6m away from the butt end;

[0023] S9, the third lowering of the pipe section

[0024] The third time it is lowered to the design bottom elevation;

[0025] S10, tube segment implantation

[0026] Control the installation cable to plant the pipe section in place;

[0027] S11, pull and close docking

[0028] The pull-and-close docking is divided into three stages: pull-and-close jack lap, pre-tightening, distance pull-and-close, and tension pull-and-close;

[0029] S12, hydraulic pressure welding

[0030] Hydraulic pressing is divided into primary hydraulic pressing and secondary hydraulic pressing.

[0031] In step S5, the specific operations of lowering the pipe segment for the first time are as follows:

[0032] Four engines simultaneously lowered four L-cables to a point where the head of the pipe segment was 10.2m above the designed elevation of the bed. The L-cable lowering speed was controlled to no more than 0.1m / min. Deck crews were informed before lowering the L-cables, every 50cm, and after lowering was complete. When stationary, the L-cables were adjusted to a consistent length.

[0033] During the lowering process, the four H cables and eight M cables are synchronously inched to adjust the relative position of the ship tube. The longitudinal swing of the ship tube is no more than 10cm, and the cable force of the H cable is controlled to be no more than 30t, and the cable force of the M cable is controlled to be no more than 30t.

[0034] During the lowering process, the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe are lowered simultaneously;

[0035] Divers enter the water in advance to observe the spacing and height differences between pipe sections. The pipe sections are lowered to a position 1m away from the top of the guide bracket to begin verifying the position of the pipe sections.

[0036] In step S6, the specific operations for adjusting the longitudinal slope are as follows:

[0037] According to the actual slope requirements, adjust the lowering distance of the four L cables to ensure that the lateral inclination of the pipe section is less than 0.01° and the longitudinal slope error is less than 0.01%;

[0038] During the process of lowering the L-cable, the pulling and closing cables and the L-cable hydraulic oil pipe are lowered synchronously, and the corresponding H-cable is retracted and released, the plane position of the installation vessel and the pipe segment is maintained, and the cable force of the H-cable is controlled to be no more than 30t.

[0039] In step S7, the specific operation of lowering the pipe segment for the second time is as follows:

[0040] Four engines simultaneously lowered four L-cables to a distance of 0.2m from the bed, controlling the lowering speed of the L-cables to no more than 0.1m / min. Deck crews were informed before and after the lowering of the L-cables, and the length of the L-cables was adjusted during parking.

[0041] During the lowering process, the four H cables are synchronously inched to adjust the plane position of the pipe segment to ensure that the position deviation of the axis of the pipe segment tail end is no more than 2cm, and the cable force of the H cable is controlled to be no more than 30t;

[0042] Synchronously lower the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe;

[0043] The diver monitors the process of the guide rod entering the guide bracket and reports any misalignment or other abnormal conditions in a timely manner.

[0044] In step S8, the specific operation of the third twisting of the pipe segment is as follows:

[0045] The H-cable is retracted and released in an inch-by-inch manner to twist the pipe segment to 0.6m away from the butt end. During the twisting and moving process, the H-cable force is controlled to keep the plane position of the pipe segment stable. The diver monitors the status of the guide rod in the guide bracket and reports any misalignment or other abnormal conditions in a timely manner.

[0046] In step S9, the specific operation of lowering the pipe segment for the third time is as follows:

[0047] Four engines synchronously control the lowering of the L-cable to the designed bottom elevation. Deck crews are informed before and after the lowering of the L-cable is completed. The length of the L-cable is adjusted when the cable is parked.

[0048] During the lowering process, the four H cables are synchronously inched to adjust the plane position of the pipe segment to ensure that the position deviation of the axis of the pipe segment tail end is no more than 2cm, and the cable force of the H cable is controlled to be no more than 30t;

[0049] Synchronously lower the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe;

[0050] The diver monitors the status of the guide rod in the guide bracket and reports any misalignment or other abnormal conditions in a timely manner.

[0051] In step S10, the specific operation of tube segment implantation is as follows:

[0052] The lifting force of a single L-cable of the installation vessel is controlled to be 100t. Four machines are used to lower four L-cables synchronously until the average horizontal position of the installation vessel is 6.45m. Divers check the seating and deviation of the guide rods. During the lowering process, the four H-cables are controlled by inching according to the data of the measurement and control system to adjust the plane position of the pipe segment so that the pipe segment posture meets the implantation requirements, ensuring that the transverse inclination of the pipe segment is less than 0.01°, the longitudinal slope error is less than 0.01%, and the position deviation of the axis of the tail end of the pipe segment is no more than 2cm. Implantation is carried out only after the implantation conditions are met.

[0053] In step S11, the specific operation of pulling and closing the docking is:

[0054] S111, pull-and-close jack overlap and pre-tighten

[0055] When the pipe segment is lowered to 3m from the bed, the pulling and closing cable is extended in advance, the oil circuit is switched, the active pulling and closing unit is controlled to be extended in advance, and preparations for splicing are made. The extension length is set according to the end face distance to ensure a successful splicing in one go. After the pipe segment is planted, the active pulling and closing unit is controlled to splice with the passive pulling and closing unit, and the diver checks and confirms. The jack is pulled to 80t for pre-tightening to eliminate the gap between the active and passive pulling and closing units and the splicing pedestal, and the pipe segment spacing displayed by the pulling and closing jack is recorded as the starting spacing. During the splicing process, the diver confirms the splicing situation and continuously checks whether there are any foreign objects in the steel shell at the docking end. After confirming that the splicing is completed and there are no foreign objects at the docking end, the diver evacuates the docking and pulling and closing area to prepare for splicing.

[0056] The order of the pulling and closing action is: the rotary jack is raised, the pulling and closing jack is extended, the rotary jack is lowered, and the pulling and closing jack is pre-tightened;

[0057] The dismantling action sequence is: release the pulling jack, raise the rotating jack, retract the pulling jack, retract the rotating jack, and dismantle the equipment;

[0058] S112, distance closing

[0059] During the pulling and closing process, the L cable force is controlled to 100t, the pulling and closing system is adjusted to the displacement synchronization mode, and the pulling and closing jack is operated twice at a medium speed to pull and close 0.25m, until the nose of the GINA waterstop of the pipe segment contacts the steel shell at the end of the previous pipe segment, completing the distance pulling and closing;

[0060] At this time, the GINA is not compressed, the water pressure inside the joint cavity displayed by the pressure sensor is the same as the water pressure at the same water depth outside the joint cavity, the flow meter is not started, and the flow rate is zero;

[0061] During the distance drawing and closing process, when the end face distance is 0.4m and the nose tips are in contact, the diver conducts two underwater inspections to confirm that there are no foreign objects in the butt joint. The data of the misalignment and end face distance between the two pipe joints on the top surface of the pipe joint are measured and verified with the drawing and closing system and the measurement and control system data.

[0062] S113, Pull and Close

[0063] The jack is set to "pressure synchronization mode" and the upper limit of the tension is set to 350t. The closing and closing jacks are activated to compress the GINA nose. When the initial watertight requirements are met, the pressure sensor reading increases, indicating that the joint cavity is watertight. The GINA nose is slightly compressed, and the pressure sensor reading increases. Since water has not yet been drained, the flow meter reading remains unchanged.

[0064] To prevent the GINA waterstop from tipping over, when the pressure sensor reading increases by 1%-2%, the technician inside the pipeline notifies the operator to stop pulling and closing. The operator inside the pipeline opens the drainage pipe valve of the joint cavity and drains the water in the joint cavity in a small amount and in a controlled manner until the pressure gauge reading drops to the initial value, helping the pulling and closing jack to compress the GINA.

[0065] Monitor the drainage speed of the joint chamber through the flow meter and observe the pressure value change on the pressure sensor at the same time. When the pressure sensor reading drops to the same as the reading before the tension is pulled, stop draining the joint chamber;

[0066] Repeat the process of pulling and closing the jack, draining and reducing pressure, until the GINA nose tip is compressed by 2-3 cm;

[0067] After the tensioning and closing is completed, the divers conduct another underwater exploration and inspection to confirm the docking situation, measure the misalignment and end face spacing data between the two pipe sections, and verify the data with the tensioning system and measurement and control system.

[0068] In step S12, the specific operation of hydraulic pressing is as follows:

[0069] S121, one-step hydraulic press

[0070] After the tension is completed, the operator in the upper pipe section opens the air inlet valve to drain water; first open the air inlet valve a quarter turn, and when the GINA waterstop is compressed by 6cm, increase the air inlet valve opening to half a turn, and when the GINA waterstop is compressed by 8cm, increase the air inlet valve opening to one turn, and when the GINA waterstop is compressed by 10cm, increase the air inlet valve opening to two turns, and when the GINA waterstop is compressed by 12cm, increase the air inlet valve opening to the maximum, and use the water head difference between the joint cavity and the upper pipe section to drain the water in the joint cavity, and now one hydraulic crimping is completed;

[0071] S122, secondary hydraulic pressure welding

[0072] The ballast water operator remotely turns on the pipe joint drainage pump to discharge the seawater in the joint cavity through the pipe joint main line to the sea at the end of the pipe joint. The GINA waterstop is compressed to achieve the required water-stopping effect, and the secondary hydraulic compression joint is completed.

[0073] During the hydraulic pressing process of step S12, after the first hydraulic pressing is completed, the diver will touch and check whether the GINA compression shape is normal and measure the distance between the pipe top pipe joint and the end face; before the second hydraulic pressing, the pipe joint ballast water system will be controlled to load 80 tons of water tanks at the head end of the pipe joint to compensate for the negative buoyancy after the joint cavity is drained.

[0074] The beneficial effects of the present invention are: the implantation position of the pipe segment of the present invention is close to the installed pipe segment, the distance of pulling and closing after the immersed pipe is implanted is small, and the axis offset of the tail end of the immersed pipe in the curved section is small; the axis position of the tail end of the pipe segment is controlled by the installation cable at the control end of the pipe segment, which is beneficial to controlling the axis deviation of the installation tail end of the immersed pipe in the curved section. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 It is a schematic diagram of the working process of the present invention;

[0076] Figure 2 Schematic diagram of the L-cable at the top of the pipe segment of the present invention;

[0077] Figure 3 It is a plan view of the pipe joints of the present invention when they are butted together;

[0078] Figure 4 for Figure 3 An enlarged view of the docking part of the middle pipe section;

[0079] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0080] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention. The following paragraphs describe the present invention in more detail by way of example with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in exact proportions. They are only used to facilitate and clearly illustrate the purpose of the embodiments of the present invention.

[0081] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may also be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may also be a central component. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0082] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0083] The present invention will be further described below with reference to the accompanying drawings and examples:

[0084] like Figures 1 to 4 As shown,

[0085] A method for controlling the axis of the tail end of a curved section immersed tube installation, comprising the following specific steps:

[0086] S1. Mooring completed

[0087] The installation vessel is moored 20m away from the docking end;

[0088] S2, the first twisting of the pipe segment

[0089] Inch-move the installation cable to move the pipe joint to a position 10m away from the butt end;

[0090] The installation cables include four H cables and eight M cables. The H cables are connected by a winch on the installation vessel from the fairlead on the pipe segment to the pre-dropped anchor on the seabed to control the horizontal position of the pipe segment. The M cables are connected by a winch on the installation vessel from the fairlead on the installation vessel to the pre-dropped anchor on the seabed to control the horizontal position of the installation vessel.

[0091] S3. Preparation for sinking

[0092] Check each working part and make preparations for sinking;

[0093] S4, the second twisting of the pipe segment

[0094] Inch-move the retractable installation cable to twist the pipe joint to a position 0.8-1m away from the butt end;

[0095] S5, the first lowering of the pipe segment

[0096] The immersed tube is lowered for the first time at a position 0.8m-1m away from the butt end;

[0097] Four engines simultaneously lowered four L-cables to a point where the head of the pipe segment was 10.2m above the designed elevation of the bed. The L-cable lowering speed was controlled to no more than 0.1m / min. Deck crews were informed before lowering the L-cables, every 50cm, and after lowering was complete. When stationary, the L-cables were adjusted to a consistent length.

[0098] During the lowering process, four H cables and eight M cables are synchronously inched to adjust the relative position of the ship tube. The longitudinal swing of the ship tube is no more than 10cm, and the cable force of the H cable is controlled to be no more than 30t, and the cable force of the M cable is controlled to be no more than 30t.

[0099] During the lowering process, the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe are lowered simultaneously;

[0100] Divers enter the water in advance to observe the distance and height difference between pipe segments. The pipe segments are lowered to a position 1m from the top of the guide bracket to begin checking the position of the pipe segments.

[0101] S6. Adjust the longitudinal slope

[0102] By adjusting the four L cables hoisted on the top of the immersed tube, the longitudinal wave of the immersed tube is made consistent with the slope of the gravel bed;

[0103] According to the actual slope requirements, adjust the lowering distance of the four L cables to ensure that the lateral inclination of the pipe section is less than 0.01° and the longitudinal slope error is less than 0.01%;

[0104] During the lowering of the L-cable, the pulling and closing cables and the L-cable hydraulic oil pipe are lowered simultaneously, and the corresponding H-cable is retracted and released, the plane position of the installation vessel and the pipe joint is maintained, and the H-cable force is controlled to be no more than 30t;

[0105] S7, the second lowering of the pipe section

[0106] Four engines simultaneously lowered four L-cables to a distance of 0.2m from the bed, controlling the lowering speed of the L-cables to no more than 0.1m / min. Deck crews were informed before and after the lowering of the L-cables, and the length of the L-cables was adjusted during parking.

[0107] During the lowering process, the four H cables are synchronously inched to adjust the plane position of the pipe segment to ensure that the position deviation of the axis of the pipe segment tail end is no more than 2cm, and the cable force of the H cable is controlled to be no more than 30t;

[0108] Synchronously lower the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe;

[0109] The diver monitors the process of the guide rod entering the guide bracket and promptly reports any misalignment or other abnormalities;

[0110] S8, the third twisting of the pipe segment

[0111] Inch-motion retract and release the H-cable to twist the pipe segment to 0.6m from the butt end. During the twisting and moving process, control the H-cable force to keep the pipe segment's plane position stable. Divers monitor the status of the guide rod in the guide bracket and promptly report any misalignment or other abnormalities.

[0112] S9, the third lowering of the pipe section

[0113] Four engines synchronously control the lowering of the L-cable to the designed bottom elevation. Deck crews are informed before and after the lowering of the L-cable is completed. The length of the L-cable is adjusted when the cable is parked.

[0114] During the lowering process, the four H cables are synchronously inched to adjust the plane position of the pipe segment to ensure that the position deviation of the axis of the pipe segment tail end is no more than 2cm, and the cable force of the H cable is controlled to be no more than 30t;

[0115] Synchronously lower the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe;

[0116] The diver monitors the status of the guide rod in the guide bracket and promptly reports any misalignment or other abnormalities;

[0117] S10, tube segment implantation

[0118] The lifting force of a single L-cable on the installation vessel is controlled to be 100t. Four machines are used to synchronously lower the four L-cables until the average horizontal position of the installation vessel is 6.45m. Divers check the seating and deviation of the guide rods. During the lowering process, the four H-cables are inched to adjust the plane position of the pipe segment according to the data from the measurement and control system to ensure that the pipe segment's lateral inclination is less than 0.01°, the longitudinal slope error is less than 0.01%, and the deviation of the axis position of the pipe segment's tail end is no more than 2cm. The pipe segment is implanted only after the implantation conditions are met.

[0119] S11, pull and close docking

[0120] The pull-and-close docking is divided into three stages: pull-and-close jack lap, pre-tightening, distance pull-and-close, and tension pull-and-close;

[0121] S111, pull-and-close jack overlap and pre-tighten

[0122] When the pipe segment is lowered to 3m from the bed, the pulling and closing cable is extended in advance, the oil circuit is switched, the active pulling and closing unit is controlled to be extended in advance, and preparations for splicing are made. The extension length is set according to the end face distance to ensure a successful splicing in one go. After the pipe segment is planted, the active pulling and closing unit is controlled to splice with the passive pulling and closing unit, and the diver checks and confirms. The jack is pulled to 80t for pre-tightening to eliminate the gap between the active and passive pulling and closing units and the splicing pedestal, and the pipe segment spacing displayed by the pulling and closing jack is recorded as the starting spacing. During the splicing process, the diver confirms the splicing situation and continuously checks whether there are any foreign objects in the steel shell at the docking end. After confirming that the splicing is completed and there are no foreign objects at the docking end, the diver evacuates the docking and pulling and closing area to prepare for splicing.

[0123] The order of the pulling and closing action is: the rotary jack is raised, the pulling and closing jack is extended, the rotary jack is lowered, and the pulling and closing jack is pre-tightened;

[0124] The dismantling action sequence is: release the pulling jack, raise the rotating jack, retract the pulling jack, retract the rotating jack, and dismantle the equipment;

[0125] S112, distance closing

[0126] During the pulling and closing process, the L cable force is controlled to 100t, the pulling and closing system is adjusted to the displacement synchronization mode, and the pulling and closing jack is operated twice at a medium speed to pull and close 0.25m, until the nose of the GINA waterstop of the pipe segment contacts the steel shell at the end of the previous pipe segment, completing the distance pulling and closing;

[0127] At this time, the GINA is not compressed, the water pressure inside the joint cavity displayed by the pressure sensor is the same as the water pressure at the same water depth outside the joint cavity, the flow meter is not started, and the flow rate is zero;

[0128] During the distance drawing and closing process, when the end face distance is 0.4m and the nose tips are in contact, the diver conducts two underwater inspections to confirm that there are no foreign objects in the butt joint. The diver also measures the tooth misalignment between the two pipe joints on the top surface of the pipe joint, the end face distance and other data, and verifies them with the drawing and closing system and the measurement and control system data.

[0129] During the distance pulling and closing process, since the center of gravity of the curved pipe segment is not on the extension line of the pulling and closing force, the pipe segment tail end may be offset due to the influence of frictional resistance during the pulling and closing process. At this time, you should pay attention to the lateral deviation of the pipe segment tail end displayed by the measurement and control system, and use the pipe segment installation cables H3 and H4 to make adjustments if necessary;

[0130] S113, Pull and Close

[0131] The jack is set to "pressure synchronization mode" and the upper limit of the tension is set to 350t. The closing and closing jacks are activated to compress the GINA nose. When the initial watertight requirements are met, the pressure sensor reading increases, indicating that the joint cavity is watertight. The GINA nose is slightly compressed, and the pressure sensor reading increases. Since water has not yet been drained, the flow meter reading remains unchanged.

[0132] To prevent the GINA waterstop from tipping over, when the pressure sensor reading increases by 1%-2%, the technician inside the pipeline notifies the operator to stop pulling and closing. The operator inside the pipeline opens the drainage pipe valve of the joint cavity and drains the water in the joint cavity in a small amount and in a controlled manner until the pressure gauge reading drops to the initial value, helping the pulling and closing jack to compress the GINA.

[0133] Monitor the drainage speed of the joint chamber through the flow meter and observe the pressure value change on the pressure sensor at the same time. When the pressure sensor reading drops to the same as the reading before the tension is pulled, stop draining the joint chamber;

[0134] Repeat the process of pulling and closing the jack, draining and reducing pressure, until the GINA nose tip is compressed by 2-3 cm;

[0135] After the tensioning and closing is completed, the divers will conduct another underwater exploration and inspection to confirm the docking situation, measure the data such as the misalignment and end face spacing between the two pipe sections, and verify the data with the tensioning system and the measurement and control system.

[0136] S12, hydraulic pressure welding

[0137] Hydraulic pressing is divided into primary hydraulic pressing and secondary hydraulic pressing;

[0138] S121, one-step hydraulic press

[0139] After the tension is completed, the operator in the upper pipe section opens the air inlet valve to drain water; first open the air inlet valve a quarter turn, and when the GINA waterstop is compressed by 6cm, increase the air inlet valve opening to half a turn, and when the GINA waterstop is compressed by 8cm, increase the air inlet valve opening to one turn, and when the GINA waterstop is compressed by 10cm, increase the air inlet valve opening to two turns, and when the GINA waterstop is compressed by 12cm, increase the air inlet valve opening to the maximum, and use the water head difference between the joint cavity and the upper pipe section to drain the water in the joint cavity. At this point, one hydraulic crimping is completed. After one hydraulic crimping is completed, the diver touches and checks whether the GINA compression shape is normal, and measures the distance between the misaligned teeth and the end face of the pipe top section;

[0140] S122, secondary hydraulic pressure welding

[0141] Before the secondary hydraulic jointing, the pipe joint ballast water system is controlled to load 80 tons of water tanks at the head end of the pipe joint to compensate for the negative buoyancy after the joint cavity is drained; the ballast water operator remotely starts the pipe joint drainage pump to discharge the seawater in the joint cavity through the pipe joint main line to the sea at the tail end of the pipe joint. The GINA waterstop is compressed to achieve the required water-stopping effect, and the secondary hydraulic jointing is completed.

[0142] The implantation position of the pipe segment of the present invention is close to the installed pipe segment, the distance between the pipe segments and the installed segments is small, and the axis offset of the tail end of the immersed pipe in the curved section is small; the position of the axis of the tail end of the pipe segment is controlled by the installation cable at the control end of the pipe segment, which is beneficial to controlling the deviation of the axis of the installation tail end of the immersed pipe in the curved section.

[0143] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or they are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A method for controlling the tail end axis of a curved section immersed tube installation, characterized in that: The specific steps are: S1. Mooring completed The installation vessel is moored 20m away from the docking end; S2, the first twisting of the pipe segment Inch-move the installation cable to move the pipe joint to a position 10m away from the butt end; The installation cables include four H cables and eight M cables. The H cables are connected by a winch on the installation vessel from the fairlead on the pipe segment to the pre-dropped anchor on the seabed to control the horizontal position of the pipe segment. The M cables are connected by a winch on the installation vessel from the fairlead on the installation vessel to the pre-dropped anchor on the seabed to control the horizontal position of the installation vessel. S3. Preparation for sinking Check each working part and make preparations for sinking; S4, the second twisting of the pipe segment Inch-move the retractable installation cable to twist the pipe joint to a position 0.8-1m away from the butt end; S5, the first lowering of the pipe segment The immersed tube is lowered for the first time at a position 0.8m-1m away from the butt end, and is lowered to a height of 10.2m from the designed top elevation of the subgrade. S6. Adjust the longitudinal slope By adjusting the four L cables hoisted on the top of the immersed tube, the longitudinal wave of the immersed tube is made consistent with the slope of the gravel bed; S7, the second lowering of the pipe section The second time, the bottom of the immersed tube is lowered to a height of 0.2m from the top of the subgrade; S8, the third twisting of the pipe segment Inch-move the installation cable to move the pipe joint to a position 0.6m away from the butt end; S9, the third lowering of the pipe section The third time it is lowered to the design bottom elevation; S10, tube segment implantation Control the installation cable to plant the pipe section in place; S11, pull and close docking The pull-and-close docking is divided into three stages: pull-and-close jack lap, pre-tightening, distance pull-and-close, and tension pull-and-close; S12, hydraulic pressure welding Hydraulic pressing is divided into primary hydraulic pressing and secondary hydraulic pressing.

2. A method for controlling the axis of the tail end of a curved section immersed tube installation according to claim 1, characterized in that: In step S5, the specific operations of lowering the pipe segment for the first time are as follows: Four engines simultaneously lowered four L-cables to a point where the head of the pipe segment was 10.2m above the designed elevation of the bed. The L-cable lowering speed was controlled to no more than 0.1m / min. Deck crews were informed before lowering the L-cables, every 50cm, and after lowering was complete. When stationary, the L-cables were adjusted to a consistent length. During the lowering process, the four H cables and eight M cables are synchronously inched to adjust the relative position of the ship tube. The longitudinal swing of the ship tube is no more than 10cm, and the cable force of the H cable is controlled to be no more than 30t, and the cable force of the M cable is controlled to be no more than 30t. During the lowering process, the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe are lowered simultaneously; Divers enter the water in advance to observe the spacing and height differences between pipe sections. The pipe sections are lowered to a position 1m away from the top of the guide bracket to begin verifying the position of the pipe sections.

3. The method for controlling the axis of the tail end of a curved section immersed tube installation according to claim 2, characterized in that: In step S6, the specific operations for adjusting the longitudinal slope are as follows: According to the actual slope requirements, adjust the lowering distance of the four L cables to ensure that the lateral inclination of the pipe section is less than 0.01° and the longitudinal slope error is less than 0.01%; During the process of lowering the L-cable, the pulling and closing cables and the L-cable hydraulic oil pipe are lowered synchronously, and the corresponding H-cable is retracted and released, the plane position of the installation vessel and the pipe segment is maintained, and the cable force of the H-cable is controlled to be no more than 30t.

4. A method for controlling the axis of the tail end of a curved section immersed tube installation according to claim 3, characterized in that: In step S7, the specific operation of lowering the pipe segment for the second time is as follows: Four engines simultaneously lowered four L-cables to a distance of 0.2m from the bed, controlling the lowering speed of the L-cables to no more than 0.1m / min. Deck crews were informed before and after the lowering of the L-cables, and the length of the L-cables was adjusted during parking. During the lowering process, the four H cables are synchronously inched to adjust the plane position of the pipe segment to ensure that the position deviation of the axis of the pipe segment tail end is no more than 2cm, and the cable force of the H cable is controlled to be no more than 30t; Synchronously lower the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe; The diver monitors the process of the guide rod entering the guide bracket and reports any misalignment or other abnormal conditions in a timely manner.

5. The method for controlling the axis of the tail end of a curved section immersed tube installation according to claim 4, characterized in that: In step S8, the specific operation of the third twisting of the pipe segment is as follows: The H-cable is retracted and released in an inch-by-inch manner to twist the pipe segment to 0.6m away from the butt end. During the twisting and moving process, the H-cable force is controlled to keep the plane position of the pipe segment stable. The diver monitors the status of the guide rod in the guide bracket and reports any misalignment or other abnormal conditions in a timely manner.

6. The method for controlling the tail end axis of a curved section immersed tube installation according to claim 5, characterized in that: In step S9, the specific operation of lowering the pipe segment for the third time is as follows: Four engines synchronously control the lowering of the L-cable to the designed bottom elevation. Deck crews are informed before and after the lowering of the L-cable is completed. The length of the L-cable is adjusted when the cable is parked. During the lowering process, the four H cables are synchronously inched to adjust the plane position of the pipe segment to ensure that the position deviation of the axis of the pipe segment tail end is no more than 2cm, and the cable force of the H cable is controlled to be no more than 30t; Synchronously lower the ballast water underwater cable, the pulling and closing cable, and the L-cable hydraulic oil pipe; The diver monitors the status of the guide rod in the guide bracket and reports any misalignment or other abnormal conditions in a timely manner.

7. The method for controlling the tail end axis of a curved section immersed tube installation according to claim 6, characterized in that: In step S10, the specific operation of tube segment implantation is as follows: The lifting force of a single L-cable of the installation vessel is controlled to be 100t. Four machines are used to lower four L-cables synchronously until the average horizontal position of the installation vessel is 6.45m. Divers check the seating and deviation of the guide rods. During the lowering process, the four H-cables are controlled by inching according to the data of the measurement and control system to adjust the plane position of the pipe segment so that the pipe segment posture meets the implantation requirements, ensuring that the transverse inclination of the pipe segment is less than 0.01°, the longitudinal slope error is less than 0.01%, and the position deviation of the axis of the tail end of the pipe segment is no more than 2cm. Implantation is carried out only after the implantation conditions are met.

8. The method for controlling the tail end axis of a curved section immersed tube installation according to claim 7, characterized in that: In step S11, the specific operation of pulling and closing the docking is: S111, pull-and-close jack overlap and pre-tighten When the pipe segment is lowered to 3m from the bed, the tensioning and closing cables are extended in advance, the oil circuit is switched, and the active tensioning and closing unit is controlled to be extended in advance to prepare for the splicing. The extension length is set according to the end-face distance to ensure a successful splicing in one go. After the pipe segment is planted, the active and passive tensioning and closing units are controlled to splice, and the diver checks and confirms. The jack is pulled to 80t for pre-tightening to eliminate the gap between the active and passive tensioning and closing units and the tensioning and closing pedestal. The pipe segment spacing displayed by the tensioning and closing jack is recorded as the starting spacing. During the splicing process, the diver confirms the splicing status and continuously checks whether there are any foreign objects on the steel shell at the docking end. After confirming that the splicing is completed and there are no foreign objects at the docking end, the diver evacuates the docking and splicing area to prepare for splicing; The order of the pulling and closing action is: the rotary jack is raised, the pulling and closing jack is extended, the rotary jack is lowered, and the pulling and closing jack is pre-tightened; The dismantling action sequence is: release the pulling jack, raise the rotating jack, retract the pulling jack, retract the rotating jack, and dismantle the equipment; S112, distance closing During the pulling and closing process, the L cable force is controlled to 100t, the pulling and closing system is adjusted to the displacement synchronization mode, and the pulling and closing jack is operated twice at a medium speed to pull and close 0.25m, until the nose of the GINA waterstop of the pipe segment contacts the steel shell at the end of the previous pipe segment, completing the distance pulling and closing; At this time, the GINA is not compressed, the water pressure inside the joint cavity displayed by the pressure sensor is the same as the water pressure at the same water depth outside the joint cavity, the flow meter is not started, and the flow rate is zero; During the distance drawing and closing process, when the end face distance is 0.4m and the nose tips are in contact, the diver conducts two underwater inspections to confirm that there are no foreign objects in the butt joint. The data of the misalignment and end face distance between the two pipe joints on the top surface of the pipe joint are measured and verified with the drawing and closing system and the measurement and control system data. S113, Pull and Close The jack is set to "pressure synchronization mode" with a maximum tension of 350t. The closing and closing jacks are activated to compress the GINA nose. When the initial watertightness requirement is met, the pressure sensor reading increases, indicating that the joint cavity is watertight. The GINA nose is slightly compressed, and the pressure sensor reading increases. Since water has not yet been drained, the flow meter reading remains unchanged. To prevent the GINA waterstop from tipping over, when the pressure sensor reading increases by 1%-2%, the technician inside the pipeline notifies the operator to stop pulling and closing. The operator inside the pipeline opens the drainage pipe valve of the joint cavity and drains the water in the joint cavity in a small amount and in a controlled manner until the pressure gauge reading drops to the initial value, helping the pulling and closing jack to compress the GINA. Monitor the drainage speed of the joint chamber through the flow meter and observe the pressure value change on the pressure sensor at the same time. When the pressure sensor reading drops to the same as the reading before the tension is pulled, stop draining the joint chamber; Repeat the process of pulling and closing the jack, draining and reducing pressure, until the GINA nose tip is compressed by 2-3 cm; After the tensioning and closing is completed, the divers conduct another underwater exploration and inspection to confirm the docking situation, measure the misalignment and end face spacing data between the two pipe sections, and verify the data with the tensioning system and measurement and control system.

9. The method for controlling the tail end axis of a curved section immersed tube installation according to claim 8, characterized in that: In step S12, the specific operation of hydraulic pressing is as follows: S121, one-step hydraulic press After the tension is completed, the operator in the upper pipe section opens the air inlet valve to drain water; first open the air inlet valve a quarter turn, and when the GINA waterstop is compressed by 6cm, increase the air inlet valve opening to half a turn, and when the GINA waterstop is compressed by 8cm, increase the air inlet valve opening to one turn, and when the GINA waterstop is compressed by 10cm, increase the air inlet valve opening to two turns, and when the GINA waterstop is compressed by 12cm, increase the air inlet valve opening to the maximum, and use the water head difference between the joint cavity and the upper pipe section to drain the water in the joint cavity, and now one hydraulic crimping is completed; S122, secondary hydraulic pressure welding The ballast water operator remotely turns on the pipe joint drainage pump to discharge the seawater in the joint cavity through the pipe joint main line to the sea at the end of the pipe joint. The GINA waterstop is compressed to achieve the required water-stopping effect, and the secondary hydraulic compression joint is completed.

10. A method for controlling the axis of the tail end of a curved section immersed tube installation according to claim 9, characterized in that: During the hydraulic pressing process of step S12, after the first hydraulic pressing is completed, the diver will touch and check whether the GINA compression shape is normal and measure the distance between the pipe top pipe joint and the end face; before the second hydraulic pressing, the pipe joint ballast water system will be controlled to load 80 tons of water tanks at the head end of the pipe joint to compensate for the negative buoyancy after the joint cavity is drained.

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