A construction method for leveling the subgrade of immersed tube gravel in sections

Abstract

The invention relates to the technical field of underwater engineering, and in particular to a construction method for leveling a gravel base bed of an immersed tube in sections, wherein the gravel base bed comprises at least two segmented gravel base beds, which are leveled by using a pile-inserted leveling ship, and the pile legs of the pile-inserted leveling ship are provided with fixed brackets that can move up and down along the pile legs, and the fixed brackets enable the pile legs to be stably supported on a foundation trench; the method comprises: S1, the leveling ship is in place; S2, the pile legs are reinforced, and the first ship position leveling of the first segmented gravel base bed is performed; S3, the leveling ship is shifted, and the leveling of the first segmented gravel base bed is completed; S4, artificial material replenishment; S5, the leveling of the remaining gravel base beds is completed; the method can ensure all-weather construction, and the pile legs are not easy to slide, and can match foundation trenches of various widths, especially foundation trenches of large widths that are larger than the maximum leveling width of the leveling ship, and the method has strong applicability, low construction cost, safety and reliability, and solves the problem of leveling the gravel base bed from a process point of view, thereby achieving maximum benefit.

Description

Technical Field

[0001] The invention relates to the technical field of underwater engineering, and in particular to a construction method for leveling a submerged tube gravel base bed in sections. Background Art

[0002] At present, the submerged tube gravel bed leveling method is pile leveling, full floating or semi-floating leveling. The leveling process is full-width leveling, and the distance between the pile legs on both sides of the leveling ship is greater than the width of the foundation trench, that is, the pile legs on both sides are on the slope of the foundation trench.

[0003] Existing leveling vessels are not suitable for the working conditions of large foundation trench widths where the distance between the leveling vessel pile legs is smaller than the foundation trench width. In addition, pile-insertion leveling is prone to pile sliding when encountering broken or sloped rock foundation platforms, which poses a high construction risk. Semi-floating leveling also requires pile insertion, which is greatly affected by wind and waves, cannot meet all-weather construction requirements, and has low construction efficiency.

[0004] Although the fully floating leveling method does not require pile driving, it needs to be stationed through anchor cables. For gravel base beds that exceed its maximum leveling width, the leveling ship needs to move its position for re-stationing, and the leveling cannot be completed in one go. Like semi-floating leveling, it is greatly affected by wind and waves, cannot meet all-weather construction requirements, and has low construction efficiency. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides a construction method for leveling a submerged tube gravel base bed in sections, which is applicable to gravel base beds with large foundation trench widths, is safe and reliable, and can be constructed around the clock.

[0006] The present invention provides a construction method for leveling a gravel bed of an immersed tube in sections, wherein the gravel bed comprises at least two section gravel beds, and is leveled by using a pile-inserting leveling vessel, wherein a fixed bracket capable of moving up and down along the pile legs is arranged on the pile legs of the pile-inserting leveling vessel, wherein the plane where the fixed bracket is located is perpendicular to the pile legs, and the fixed bracket enables the pile legs to be stably supported on the foundation trench;

[0007] The construction method comprises the following steps:

[0008] S1. Level the boat into position:

[0009] After the excavation and acceptance of the immersed tube foundation trench is completed, the leveling ship is positioned at the first ship position of the first section gravel foundation bed, and the pile legs are lowered to the predetermined first ship position pile leg position, and the fixing bracket is located at the upper part of the pile legs close to the bottom of the leveling ship;

[0010] S2, pile leg reinforcement, first ship leveling of the first section gravel bed:

[0011] The fixed bracket is moved from the upper part of the pile leg to the lower part of the pile leg by using a lifting device, and the fixed bracket is tightly locked at the lower part of the pile leg, so that the pile leg is evenly stressed and the bottom of the pile leg is firmly supported on the base trench; the leveling ship starts to level the first position of the first section gravel bed along the axial direction of the base trench;

[0012] S3. The leveling ship moves to complete the leveling of the first section of the gravel bed:

[0013] When the first position is leveled, the fixing bracket is unlocked at the bottom of the pile leg, the fixing bracket is lifted from the bottom of the pile leg to the top by using the lifting device, the pile leg is folded, the leveling ship is moved to the second position of the first framed gravel bed, and the pile leg is lowered to the predetermined second position pile leg position; step S3 is repeated to complete the leveling work of the second position of the first framed gravel bed;

[0014] Repeat the above process until the first section of the gravel bed is leveled;

[0015] S4. Artificial feeding:

[0016] Move the leveling ship to the first position of the second-framing gravel bed, repeat the step S2, complete the leveling of the first position of the second-framing gravel bed, and move the leveling ship to the second position of the second-framing gravel bed;

[0017] For the pile leg position inside the first section gravel bed occupied during the leveling process of the first ship position of the second section gravel bed, an excavator is used to throw materials at fixed points, and manual diving is used to perform underwater fixed-point material replenishment and leveling to ensure the overall leveling effect of the first section gravel bed;

[0018] S5. Complete the leveling of the remaining gravel bed:

[0019] Repeat steps S3-S4 until the entire gravel bed is leveled.

[0020] The construction method of the submerged tube gravel base bed leveling in sections of this technical solution can ensure all-weather construction, and the pile legs are not easy to slip. It can match foundation trenches of various widths, especially large-width foundation trenches that are larger than the leveling width of the leveling ship. It has strong applicability, low construction cost, safety and reliability, and solves the problem of gravel base bed leveling from a technological point of view, thereby maximizing benefits.

[0021] In some embodiments of the present application, the fixing bracket is a rectangular frame structure, and sleeves are respectively provided at corresponding positions of the fixing bracket corresponding to the pile legs, and the pile legs are sleeved in the sleeves;

[0022] The lifting device is a plurality of winches evenly distributed on the leveling ship, the steel wire ropes of the winches are connected to the fixed bracket, and the winches drive the fixed bracket to move up and down along the pile legs.

[0023] In some embodiments of the present application, a plurality of retractable devices are evenly distributed circumferentially on the inner wall of the sleeve, and the retractable devices are retracted and extended along the radial direction of the sleeve. When the retractable devices are extended, they can hold the pile legs tightly. When the retractable devices are retracted, the fixed bracket can move along the pile legs.

[0024] In some embodiments of the present application, in step S2, when the fixed bracket moves from the upper part of the pile leg to the lower part of the pile leg, the retractable device is in a retracted state, and when the winch lowers the fixed bracket to a preset position, the retractable device extends, and the retractable device hugs the pile leg, so that the fixed bracket and the pile leg form a stable force system;

[0025] In step S3, the retractable device is transformed into a retracted state, the locking of the fixing bracket at the lower part of the pile leg is released, and the fixing bracket is lifted to the top of the pile leg.

[0026] In some embodiments of the present application, in order to stably support the pile legs on a broken rock foundation platform or slope, a shoe sole device is provided at the bottom of the pile legs, and the shoe sole device includes:

[0027] A ball joint structure is arranged at the bottom of the pile leg;

[0028] A supporting bottom plate, arranged below the ball joint structure;

[0029] The ball joint structure can adjust the angle of the support plate according to the slope of the base, so that the support base plate can be supported on bases that adapt to different slopes, increase the contact area, and improve the stability of the pile leg support.

[0030] In some embodiments of the present application, in step S2, when the fixed bracket moves downward to a distance of 1-2 m from the base, the retractable device extends to hold the pile legs tightly, and at this time the fixed bracket can provide more stable support for the pile legs.

[0031] In some embodiments of the present application, the gravel base bed includes at least two segmented gravel base beds, and a joint is formed at the joint of two adjacent segmented gravel base beds. The joints along the length direction of the base trench are staggered with each other. Since stress concentration is easily generated at the joints, the joints are not collinear to avoid stress concentration at the same position, and to avoid stress concentration at the joints when the joints are collinear, resulting in poor load-bearing capacity and settlement.

[0032] In some embodiments of the present application, the segmented gravel base bed includes long ridges and short ridges that are alternately arranged and parallel to each other, the width of each long ridge perpendicular to the axis of the segmented gravel base bed is different, the width of each short ridge is also different, two adjacent segmented gravel base beds are cross-arranged, the long ridges of one segmented gravel base bed are opposite to the short ridges of the adjacent segmented gravel base bed, and form a plurality of staggered seams.

[0033] Based on the above technical scheme, the construction method of the submerged tube gravel bed leveling in sections of the present invention can ensure all-weather construction, and the fixed support plate and the shoe sole device ensure that the pile legs are not easy to slide, and can match various widths of foundation trenches, especially large width foundation trenches larger than the leveling width of the leveling ship, with strong applicability, improving the utilization rate and scope of the pile-inserted leveling ship, low construction cost, safe and reliable, solving the problem of gravel bed leveling from a technical point of view, and achieving maximum benefit;

[0034] The structure of alternating long ridges and short ridges of the framed gravel bed and the staggered joints between adjacent framed gravel beds can avoid stress concentration at the joints and avoid settlement, so that the gravel bed forms a stable load-bearing layer.

[0035] It is suitable for leveling various types of soil, especially for rock foundations. The pile legs can also provide stable support for broken or sloped rock foundation platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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:

[0037] Figure 1 This is a schematic structural diagram of a gravel bed according to an embodiment of the present invention;

[0038] Figure 2 It is a structural schematic diagram of a fixed bracket in an initial position when the first segmented gravel bed is leveled according to an embodiment of the present invention;

[0039] Figure 3 It is a schematic diagram of the position relationship of the first segmented gravel bed occupied by the pile legs when the first ship position of the second segmented gravel bed is leveled according to an embodiment of the present invention;

[0040] Figure 4 is a top view of a fixing bracket according to an embodiment of the present invention;

[0041] Figure 5 It is a schematic structural diagram of a first-frame gravel bed leveling after a fixed bracket is lowered into place in an embodiment of the present invention;

[0042] Figure 6 It is a schematic structural diagram of a second section gravel bed leveling after a fixed bracket is lowered into place in an embodiment of the present invention;

[0043] Figure 7 Schematic diagram of the structure of a boot sole device according to an embodiment of the present invention.

[0044] In the figure, 10, gravel bed; 11, first section gravel bed; 111, first long ridge; 112, first short ridge; 12, second section gravel bed; 121, second long ridge; 122, second short ridge; 13, joint; 20, pile-type leveling ship; 21, pile leg; 22, first ship position pile leg position of first section gravel bed; 23, first ship position pile leg position of second section gravel bed; 24, shoe sole device; 241, ball joint structure; 242, supporting bottom plate; 30, fixing bracket; 31, mounting plate; 32, sleeve; 33, retractable device; 40, base groove; 41, base groove slope; 50, wire rope; DETAILED DESCRIPTION

[0045] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships 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 operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0047] The terms "first", "second", and "third" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Thus, a feature defined as "first", "second", and "third" may explicitly or implicitly include one or more of the features.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] This embodiment discloses a construction method for leveling a submerged pipe gravel bed in sections, which is suitable for a gravel bed with a larger width. In this embodiment, the width of the foundation trench is 45m, and the maximum leveling width of the pile-type leveling ship 20 is 35m. Therefore, the leveling of the subgrade is divided into two sections, such as Figure 1 As shown, the crushed stone base bed 10 includes a first framed crushed stone base bed 11 and a second framed crushed stone base bed 12 , and a joint 13 is formed between the first framed crushed stone base bed 11 and the second framed crushed stone base bed 12 .

[0050] Continue to see Figure 1 In this embodiment, the first framed gravel bed 11 includes alternately arranged first long ridges 111 and first short ridges 112 parallel to each other, wherein one side of the first long ridges 111 and the first short ridges 112 are aligned, and the other side is alternately arranged in long and short order, and the aligned side forms one side of the entire gravel bed. The second framed gravel bed 12 has the same structure as the first framed gravel bed 11, including alternately arranged second long ridges 121 and second short ridges 122 parallel to each other, wherein one side of the second long ridges 121 and the second short ridges 122 are aligned, and the other side is alternately arranged in long and short order, and the aligned side forms the other side of the entire gravel bed.

[0051] In this embodiment, the direction perpendicular to the axis of the first-frame crushed stone bed is the width direction of the first long ridge and the first short ridge, and the direction perpendicular to the axis of the second-frame crushed stone bed is the width direction of the second long ridge and the second short ridge. The widths of all the first long ridges 111 and all the second long ridges 121 are different, but the widths are in the range of 25-29.5m, which is less than the maximum leveling width of the leveling ship; the widths of all the first short ridges 112 and all the second short ridges 122 are also different, but the widths are in the range of 14.5-19m; the first-frame crushed stone bed is the width of the second long ridge and the second short ridge. The first long ridge 111 of the base bed 11 is arranged opposite to the second short ridge 122 of the second framed gravel base bed 12, the first short ridge 112 is arranged opposite to the second long ridge 121, the first framed gravel base bed 11 and the second framed gravel base bed 12 are arranged crosswise, the crossing depth is 6-15m, and the cross-joint joint forms a joint 13 with a width of 1m. There are multiple joints 13 along the length direction of the immersed tube foundation trench, and all the joints 13 are staggered and non-collinear. The first framed gravel base bed 11 and the second framed gravel base bed 12 of this embodiment cross each other, such as Figure 1As shown in the dotted box, all the joints 13 are staggered and not in a straight line, which avoids stress concentration at the same position when the joints are collinear, resulting in poor load-bearing capacity at the joints and settlement. The staggered joints 13 of this embodiment ensure that a stable load-bearing layer is formed after the immersed tube foundation trench is leveled.

[0052] Use a pile-type leveling ship 20 to level the gravel bed 10 in sections, such as Figure 2 As shown, a fixed bracket 30 capable of moving up and down along the pile leg 21 is provided on the pile leg 21 of the pile-type leveling ship 20, and the lifting device pulls the fixed bracket 30 to move up and down, and the plane where the fixed bracket 30 is located is perpendicular to the pile leg 21, and the fixed bracket 30 enables the pile leg 21 to be stably supported on the foundation groove 40; the gravel base bed 10 of this embodiment is located on the foundation groove 40 of the rock foundation platform, and the two sides of the foundation groove 40 have foundation groove slopes 41;

[0053] like Figure 4 As shown, in this embodiment, the fixed bracket 30 is a rectangular frame structure, and mounting plates 31 are respectively arranged at the top corners of the fixed bracket 30 corresponding to the pile legs 21. The mounting plates 31 are provided with mounting holes, and sleeves 32 extending in the up-down direction are arranged in the mounting holes, and the pile legs 21 are sleeved in the sleeves 32; a plurality of retractable devices 33 are evenly distributed around the inner wall of the sleeve 32, and the retractable devices 33 are retracted in the horizontal direction along the radial direction of the sleeve 32. When the retractable devices 33 are extended, they can hold the pile legs 21 tightly, and when the retractable devices 33 are retracted, they are separated from the pile legs 21, and the fixed bracket 30 can move along the pile legs 21. In this embodiment, the retractable devices 33 are oil cylinders or gas cylinders.

[0054] Continue to see Figure 2 The fixed bracket 30 is pulled up and down by a lifting device, and the lifting device is a plurality of winches (not shown in the figure) evenly distributed on the pile-inserting leveling ship 20. The wire rope 50 of the winch is connected to the fixed bracket 30, and the winch drives the fixed bracket 30 along the pile leg 21 through the wire rope 50.

[0055] The method for leveling a gravel bed in sections of this embodiment includes the following steps:

[0056] S1. Level the boat into position:

[0057] After the excavation and acceptance of the immersed tube foundation trench 40 is completed, Figure 2-Figure 3 As shown, the pile-type leveling ship 20 is in place at the first ship position of the first section gravel bed 10, and the pile legs 21 are lowered to the first ship position pile leg position 22 of the predetermined first section gravel bed, and the fixed bracket 30 is located on the upper part of the pile legs 21 close to the bottom of the leveling ship; at this time, the retractable device 33 is in a retracted state, and the fixed bracket 30 is hoisted by the wire rope 50 of the winch and will not move relative to the pile legs 21;

[0058] S2, pile leg reinforcement, first ship leveling of the first section gravel bed:

[0059] like Figure 5 As shown, a winch is used to drive a steel wire rope 50 to lower the fixed bracket 30 from the upper part of the pile leg 21 to the lower part of the pile leg. When the fixed bracket 30 is lowered to 1-2m from the base, the retractable device 33 is extended, and the clamp is locked at the lower part of the pile leg 21, so that the fixed bracket 30, the pile leg 21 and the hull of the leveling ship form a stable force system, and the bottom of the pile leg 21 is firmly supported on the base trench 40; the leveling ship begins to level the first position of the first segmented gravel bed 11 along the axial direction of the base trench 40, and the widths of the first long ridges 111 on the first position are all different, and the widths of the first short ridges 112 are also different;

[0060] S3. The leveling ship moves to complete the leveling of the first section of the gravel bed:

[0061] When the first position is leveled, the retractable device 33 is recovered, the lock of the fixed bracket 30 at the lower part of the pile leg 21 is released, and the fixed bracket 30 is lifted from the lower part of the pile leg 21 to the upper position by using a winch, the pile leg 21 is retracted, and the leveling ship is moved to the second position of the first section gravel bed 11, and the pile leg is lowered to the predetermined second position pile leg position; step S3 is repeated to complete the leveling work of the second position of the first section gravel bed 11, the width of the first long ridge 111 on the second position is different from the width of the first long ridge on the first position, and the widths of the first long ridges 111 on the second position are also different, the width of the first short ridge 112 on the second position is different from the width of the first short ridge 112 on the first position, and the widths of the first short ridges 112 on the second position are also different;

[0062] Repeat the above process until the first framed gravel bed 11 is leveled, and the widths of all first long ridges 111 of the first framed gravel bed 11 are different, and the widths of all first short ridges 112 are also different;

[0063] S4. Artificial feeding:

[0064] Move the leveling ship to the first position of the second section gravel bed 12, such as Figure 6 As shown, the pile leg 21 is lowered to the first position of the pile leg position 23 of the second framed gravel bed, and the step S2 is repeated to complete the leveling of the first position of the second framed gravel bed 12, and the leveling ship moves to the second position of the second framed gravel bed 12;

[0065] During the leveling process of the first position of the second section gravel bed, one side leg 21 will occupy part of the gravel bed of the first position that damages the gravel bed of the first section, such as Figure 3As shown, the first ship leg position 23 of the second frame gravel bed located inside the first frame gravel bed 11 adopts the method of using an excavator to dump materials at a fixed point, and artificial diving to perform underwater fixed-point material replenishment and leveling to ensure the overall leveling effect of the first frame gravel bed;

[0066] S5. Complete the leveling of the remaining gravel bed:

[0067] Repeat steps S3-S4 to complete the leveling of the second-frame gravel base bed. The widths of all second long ridges 121 of the second-frame gravel base bed 12 are different, and the widths of all second short ridges 122 are also different, so that the joints 13 formed between the first-frame gravel base bed 11 and the second-frame gravel base bed 12 are staggered and not collinear. Then, the first-frame gravel base bed 11 occupied and damaged by the pile legs 21 is artificially supplemented until the entire gravel base bed is leveled.

[0068] In this embodiment, in order to stably support the pile leg 21 on the broken rock foundation platform or slope, a shoe sole device 24 is provided at the bottom of the pile leg 21. Figure 7 As shown, the shoe sole device 24 includes:

[0069] A ball joint structure 241 is provided at the bottom of the pile leg 21;

[0070] The support bottom plate 242 is arranged below the ball joint structure 241. The support bottom plate 242 can increase the contact area with the base groove 40. At the same time, since the ball joint structure can rotate in all directions, the support bottom plate 242 can adapt to the base with different slopes, thereby improving the stability of the pile leg 21 support. Figure 2 As shown, at the foundation trench slope 41, the pile legs 21 can also provide stable support.

[0071] For the leveling of muddy base beds, there is no need to consider the problem of pile sliding. There is no need to set the sole device 24 at the bottom of the pile leg 21. It can be directly inserted into the mud, and there is no need to lower the fixed bracket to reinforce the pile leg. During the leveling process of sections, when the gravel base bed of the next section is leveled, the gravel base bed of the previous section occupied and damaged by the pile legs needs to be manually supplemented.

[0072] In other embodiments, when the gravel base includes three or more segmented gravel bases, they are respectively two segmented gravel bases located on both sides of the gravel base and one or more segmented gravel bases located in the middle; the segmented gravel base located at the edge position has the same structure as the first segmented gravel base 11 and the second segmented gravel base 12 of the previous embodiment, with long ridges and short ridges alternately arranged and parallel to each other, one side is aligned, and the other side is long and short crossed; the segmented gravel base located in the middle position also has long ridges and short ridges alternately and in parallel, but the long ridges and short ridges are symmetrically arranged with respect to the central axis of the segmented gravel base, that is, both sides of the segmented gravel base are of alternating long and short structures, which is convenient for crossing the segmented gravel bases on both sides to form bent joints, so that all joints of the gravel base are load-bearing and stable to avoid settlement.

[0073] Based on the above technical scheme, the construction method of the submerged tube gravel bed leveling in sections of the present invention can ensure all-weather construction, and the fixed support plate and the shoe sole device ensure that the pile legs are not easy to slide, and can match various widths of foundation trenches, especially large width foundation trenches larger than the leveling width of the leveling ship, with strong applicability, low construction cost, safety and reliability, and solves the problem of gravel bed leveling from a technical point of view, achieving maximum benefits;

[0074] The structure of alternating long ridges and short ridges of the framed gravel bed and the curved joints between adjacent framed gravel beds can avoid settlement at the joints, so that the gravel bed forms a stable load-bearing layer;

[0075] It is suitable for leveling various types of soil, especially for rock foundations. The pile legs can also provide stable support for broken or sloped rock foundation platforms.

[0076] 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.

[0077] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A construction method for leveling the gravel bed of a immersed tube, characterized in that: The crushed stone bed comprises at least two framed crushed stone beds, the framed crushed stone beds comprise long ridges and short ridges which are alternately arranged and parallel to each other, the widths of the long ridges perpendicular to the axes of the framed crushed stone beds are different, the widths of the short ridges are also different, two adjacent framed crushed stone beds are cross-arranged, the long ridges of one framed crushed stone bed and the short ridges of the adjacent framed crushed stone bed are arranged opposite to each other, and a plurality of mutually staggered joints are formed; Use a pile-type leveling ship for leveling, wherein the pile legs of the pile-type leveling ship are provided with a fixed bracket that can move up and down along the pile legs, the plane where the fixed bracket is located is perpendicular to the pile legs, and the fixed bracket enables the pile legs to be stably supported on the base trench; The construction method comprises the following steps: S1. Level the boat into position: After the excavation and acceptance of the immersed tube foundation trench is completed, the leveling ship is positioned at the first ship position of the first section gravel foundation bed, and the pile legs are lowered to the predetermined first ship position pile leg position, and the fixing bracket is located at the upper part of the pile legs close to the bottom of the leveling ship; S2, pile leg reinforcement, first ship leveling of the first section gravel bed: The fixing bracket is moved from the upper part of the pile leg to the lower part of the pile leg by using a lifting device, and the fixing bracket is tightly locked at the lower part of the pile leg, so that the pile leg is evenly stressed and the bottom of the pile leg is firmly supported on the base trench; the leveling ship starts to level the first position of the first section gravel bed along the axial direction of the base trench; S3. The leveling ship moves to complete the leveling of the first section of the gravel bed: When the first position is leveled, the fixing bracket is unlocked at the bottom of the pile leg, the fixing bracket is lifted from the bottom of the pile leg to the top by using the lifting device, the pile leg is folded, the leveling ship is moved to the second position of the first framed gravel bed, and the pile leg is lowered to the predetermined second position pile leg position; step S3 is repeated to complete the leveling work of the second position of the first framed gravel bed; Repeat the above process until the first section of the gravel bed is leveled; S4. Artificial feeding: Move the leveling ship to the first position of the second-frame gravel bed, repeat step S2, complete the leveling of the first position of the second-frame gravel bed, and move the leveling ship to the second position of the second-frame gravel bed; For the pile leg position inside the first section gravel bed occupied during the leveling process of the first ship position of the second section gravel bed, an excavator is used to throw materials at fixed points, and manual diving is used to perform underwater fixed-point material replenishment and leveling to ensure the overall leveling effect of the first section gravel bed; S5. Complete the leveling of the remaining gravel bed: Repeat steps S3-S4 until the entire gravel bed is leveled; The fixing bracket is a rectangular frame structure, and sleeves are respectively provided at corresponding positions of the fixing bracket corresponding to the pile legs, and the pile legs are sleeved in the sleeves; The lifting device is a plurality of winches evenly distributed on the leveling ship, the steel wire ropes of the winches are connected to the fixed bracket, and the winches drive the fixed bracket to move up and down along the pile legs; A plurality of retractable devices are evenly distributed circumferentially on the inner wall of the sleeve. The retractable devices are retracted and contracted along the radial direction of the sleeve. When the retractable devices are extended, they can hold the pile legs tightly. When the retractable devices are retracted, the fixed bracket can move along the pile legs.

2. The construction method for screed leveling of immersed tube gravel bed according to claim 1 is characterized in that: In step S2, when the fixed bracket moves from the upper part of the pile leg to the lower part of the pile leg, the retractable device is in a retracted state, and when the winch lowers the fixed bracket to a preset position, the retractable device extends, and the retractable device hugs the pile leg, so that the fixed bracket and the pile leg form a stable force-bearing system; In step S3, the retractable device is transformed into a retracted state, the locking of the fixing bracket at the lower part of the pile leg is released, and the fixing bracket is lifted to the top of the pile leg.

3. The construction method for screed leveling of immersed tube gravel bed according to claim 1 is characterized in that: In order to provide a stable support for the pile legs on a broken rock foundation platform or slope, a shoe sole device is provided at the bottom of the pile legs, and the shoe sole device includes: A ball joint structure is arranged at the bottom of the pile leg; A supporting bottom plate, arranged below the ball joint structure; The ball joint structure can adjust the angle of the support plate according to the slope of the base, so that the support base plate can be supported on bases that adapt to different slopes.

4. The construction method for screed leveling of immersed tube gravel bed according to claim 1 is characterized in that: In step S2, when the fixed bracket moves downward to a distance of 1-2 m from the base, the retractable device extends to hold the pile legs tightly, and at this time the fixed bracket can provide more stable support for the pile legs.

Images