A method for controlling the ballasting posture of immersed tubes in curved sections

Abstract

The present invention is a method for controlling the ballast posture of a curved section sunk pipe, comprising: obtaining the planar position of the centroid of the pipe section by theoretically calculating the shape of the pipe section; leveling the pipe section so that the center of gravity and the centroid of the pipe section are in the same straight line; then calculating the planar position of the centroid of each water tank based on the shape and position of each water tank, and calculating the loading ratio of each water tank; performing ballasting according to the loading ratio in the leveled state to see whether balance is maintained; performing ballasting according to the accurate loading ratio of each water tank so that the center of gravity position of the pipe section is always kept in the same straight line with the centroid position of the pipe section, thereby ensuring the stability of the pipe section posture. The present invention calculates the shape and position of the ballast water tank of the curved section pipe section to obtain the theoretical ratio of the outer side of the arc to the inner side of the arc when the curved section pipe section is ballasted, verifies the ballast amount of the water tank during the sinking drill, and determines the loading during formal installation; ensures that the curved section pipe section maintains its posture when ballasted during formal installation through theoretical calculation and experimental verification.

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 ballasting posture of a curved section immersed tube. Background Art

[0002] During the construction of submarine tunnels, some immersed tube tunnels are curved, such as the Dalian Bay Subsea Tunnel. The Dalian Bay Subsea Tunnel is the immersed tube tunnel with the largest curvature among the existing immersed tube tunnels in China. The ballast water tanks of the curved section are arranged asymmetrically. The traditional ballasting process for the straight section immersed tube is not suitable for the sinking and ballasting preparation of the curved section immersed tube. If the uniform ballasting method is used, it will cause the pipe section posture to deflect, affecting the final construction quality. Summary of the Invention

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

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

[0005] A method for controlling the ballasting posture of a curved section immersed tube, specifically comprising:

[0006] S1. Drills before ballasting of immersed tubes

[0007] S11. Calculate the planar position of the centroid of the pipe segment by theoretically calculating the pipe segment shape;

[0008] S12. Level the pipe section so that the center of gravity and centroid of the pipe section are in the same straight line;

[0009] S13, then calculating the plane position of the centroid of each water tank by calculating the shape and position of each water tank, and calculating the loading ratio of each water tank;

[0010] S14, in the leveled state, ballasting is performed according to the loading ratio calculated in step S13 to see if balance is maintained. If balance cannot be maintained, further calculation of the loading ratio is performed, and adjustments are made before rehearsing. If balance can be maintained, the loading ratio is proven to be correct.

[0011] S2. Immersed tube ballasting operation

[0012] The ballasting is performed according to the accurate loading ratio of each water tank in step S14, so that the center of gravity of the pipe segment is always kept in the same straight line with the center of shape of the pipe segment, ensuring the stability of the pipe segment.

[0013] In step S12, when the pipe section is leveled, an inclinometer is set inside the pipe section, and each water tank is loaded by looking at the data of the inclinometer to level the pipe section.

[0014] In step S13, when calculating the plane position of the centroid of each water tank, a coordinate axis is established with the center of the axis of the curved pipe section as the zero point.

[0015] In step S2, the attitude control index is that the longitudinal tilt of the submerged tube is less than 0.01%, and the heel control is less than 0.01°.

[0016] The beneficial effects of the present invention are as follows: the present invention calculates the shape and position of the ballast water tank of the curved section pipe segment, obtains the theoretical ratio of the outer side of the arc to the inner side of the arc when the curved section pipe segment is ballasted, and verifies the ballast amount of the water tank during the sinking drill to determine the loading during formal installation; through theoretical calculation and experimental verification, it is ensured that the curved section pipe segment maintains its posture when it is formally installed and ballasted. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a layout diagram of the ballast water tanks for the straight section immersed tubes of the Dalian Bay submarine tunnel in a specific embodiment of the present invention;

[0018] Figure 2 This is a layout diagram of the immersed tube ballast water tanks for the curved section of the Dalian Bay submarine tunnel in a specific embodiment of the present invention;

[0019] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] 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.

[0021] 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.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those 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.

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0024] A method for controlling the ballasting posture of a curved section immersed tube, specifically comprising:

[0025] S1. Drills before ballasting of immersed tubes

[0026] S11. Calculate the planar position of the centroid of the pipe segment by theoretically calculating the pipe segment shape;

[0027] S12. Level the pipe section so that the center of gravity and centroid of the pipe section are in the same straight line;

[0028] S13, then calculating the plane position of the centroid of each water tank by calculating the shape and position of each water tank, and calculating the loading ratio of each water tank;

[0029] S14, in the leveled state, ballasting is performed according to the loading ratio calculated in step S13 to see if balance is maintained. If balance cannot be maintained, further calculation of the loading ratio is performed, and adjustments are made before rehearsing. If balance can be maintained, the loading ratio is proven to be correct.

[0030] S2. Immersed tube ballasting operation

[0031] The ballasting is performed according to the accurate loading ratio of each water tank in step S14, so that the center of gravity of the pipe segment is always kept in the same straight line with the center of shape of the pipe segment, ensuring the stability of the pipe segment.

[0032] In step S12, when the pipe section is leveled, an inclinometer is set inside the pipe section, and each water tank is loaded by looking at the data of the inclinometer to level the pipe section.

[0033] In step S13, when calculating the plane position of the centroid of each water tank, a coordinate axis is established with the center of the axis of the curved pipe section as the zero point.

[0034] In step S2, the attitude control index is that the longitudinal tilt of the submerged tube is less than 0.01%, and the heel control is less than 0.01°.

[0035] The present invention calculates the shape and position of the ballast water tank of the curved pipe segment to obtain the theoretical ratio of the outer side of the arc to the inner side of the arc when the curved pipe segment is ballasted, and verifies the ballast amount of the water tank during the sinking drill to determine the loading during formal installation. Theoretical calculation and experimental verification ensure that the curved pipe segment maintains its posture when it is formally installed and ballasted. Specific embodiment:

[0037] Taking the Dalian Bay Subsea Tunnel as an example, the arrangement of the ballast water tanks in the straight section of the immersed tube is shown in Figure 1 The ballasting process for preparing for the sinking of the straight section of the submerged tube involves distributing the ballast to eliminate the freeboard of the tube section evenly across six tanks, and distributing the ballast to provide negative buoyancy evenly across the four forward and aft tanks. Because the ballast tanks for the straight section of the submerged tube are symmetrically distributed, the average ballast load across each tank has no effect on the tube section's posture.

[0038] The arrangement of the ballast water tanks in the curved section is shown in Figure 2 The distribution of ballast water tanks is asymmetrical. If the original straight-line segment immersed tube sinking preparation ballasting process is adopted, that is, each water tank is evenly ballasted, the centroid position of the inner water tank is closer to the pipe segment axis than the outer water tank, and the center of gravity position of the ballast water in the inner water tank is closer to the pipe segment axis than the outer water tank. The influence of the gravity of the ballast water in the inner water tank on the pipe segment posture is smaller than that of the outer water tank, and the pipe segment posture is deflected.

[0039] Therefore, the traditional method of uniformly ballasting the straight section of the immersed tube is not applicable. It is necessary to design a ballasting posture control method for the curved section of the immersed tube based on the arrangement of the ballast water tanks for some curved sections of the Dalian Bay submarine tunnel. The posture of the immersed tube remains unchanged during the ballasting process, and the center of gravity and the centroid of the tube segment must always remain on the same straight line during the ballasting process.

[0040] The specific control process is as follows:

[0041] The plane position of the centroid of the pipe segment is determined by theoretical calculation of the pipe segment shape. During the sinking drill, the pipe segment is leveled by adjusting the ballast volume of each water tank so that the center of gravity of the pipe segment is adjusted to the straight line where the centroid is located. The plane position of the centroid of each water tank is then calculated based on the shape and position of each water tank. In other words, the plane position of the center of gravity of the ballast water in each water tank is calculated. By controlling the effect of the ballast water in each water tank on the center of gravity of the pipe segment, the center of gravity of the pipe segment is kept stable, that is, the center of gravity of the pipe segment is always kept in the same straight line with the centroid of the pipe segment, and the pipe segment posture is stable.

[0042] The calculations were based on the shape and position of the six ballast water tanks for the curved section of the Dalian Bay Subsea Tunnel project. The axis of the immersed tube is 148 meters long, the radius of curvature is 1050 meters, and the center of buoyancy of the curved section is located at (0 meters, -0.753 meters). The six ballast water tanks are located at the roadway entrance within the section. The outer tank is 18.556 meters long and 12.648 meters wide, while the inner tank is 18.166 meters long and 12.652 meters wide. By establishing the coordinate axis with the center of the curved pipe segment axis as the zero point, the centroid of the six water tanks in the xy plane is (0m, -0.1954m), of which the centroid of the three water tanks outside the arc in the xy plane is (0m, 8.841m), and the centroid of the three water tanks inside the arc in the xy plane is (0m, -9.393m). The centroid of the outer water tank is 9.594m away from the buoyancy center of the pipe segment, and the buoyancy center of the inner water tank is 9.198m away from the buoyancy center of the pipe segment. In order to make the center of gravity of the ballast water consistent with the y-coordinate of the buoyancy center of the curved pipe segment, the load cannot be evenly applied when increasing the ballast. It is necessary to load according to the ratio of outer arc: inner arc = 47.4%:52.6%.

[0043] This calculation method and the corresponding calculation results of the shape and size of the curved section pipe segments of the Dalian Bay Undersea Tunnel were successfully verified and applied during the sinking drill and installation of the curved section pipe segments of the Dalian Bay Undersea Tunnel. The longitudinal and transverse inclination control effects during the loading process of the curved section pipe segments were good.

[0044] 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 ballasting posture of a curved section immersed tube, characterized in that: Specifically include: S1. Drills before ballasting of immersed tubes S11. Calculate the planar position of the centroid of the pipe segment by theoretically calculating the pipe segment shape; S12. Level the pipe section so that the center of gravity and centroid of the pipe section are in the same straight line; S13. Calculate the plane position of the centroid of each water tank based on the shape and position of each water tank, and calculate the loading ratio of each water tank. When calculating the plane position of the centroid of each water tank, establish a coordinate axis with the center of the axis of the curved pipe section as the zero point. S14, in the leveled state, ballasting is performed according to the loading ratio calculated in step S13 to see if balance is maintained. If balance cannot be maintained, further calculation of the loading ratio is performed, and adjustments are made before rehearsing. If balance is maintained, the loading ratio is proved to be correct. S2. Immersed tube ballasting operation The ballasting is performed according to the accurate loading ratio of each water tank in step S14, and the water tank is controlled within a certain attitude control index so that the center of gravity of the pipe segment is always kept in the same straight line with the centroid of the pipe segment, ensuring the stability of the pipe segment attitude.

2. The method for controlling the ballasting posture of a curved section immersed tube according to claim 1, characterized in that: In step S12, when the pipe section is leveled, an inclinometer is set inside the pipe section, and each water tank is loaded by looking at the data of the inclinometer to level the pipe section.

3. The method for controlling the ballasting posture of a curved section immersed tube according to claim 2, characterized in that: In step S2, the attitude control index is that the longitudinal tilt of the submerged tube is less than 0.01%, and the heel control is less than 0.01°.

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