Semi-submersible river channel dredging platform and dredging method

Abstract

The present application relates to river dredging technical field, specifically to a kind of semi-submersible river channel expansion platform and expansion method, expansion platform includes: semi-submersible platform, the semi-submersible platform is equipped with mounting hole;Winch mechanism, the first end of the winch mechanism is connected on the semi-submersible platform, the second end of the winch mechanism is inserted into the mounting hole;Expansion device, expansion device includes milling arm, rotary unit, support arm, slurry assembly and swing driving element;Embedded pile positioning mechanism, embedded pile positioning mechanism includes drill stand, pile lifting assembly and fixed pile, drill stand is fixed on the semi-submersible platform, fixed pile is inserted into riverbed through semi-submersible platform, pile lifting assembly is connected between drill stand and fixed pile.The present application can realize synchronous operation of excavation and slagging by milling arm equipped with slurry assembly, semi-submersible platform can be designed modularly, by platform expansion combination, it can be from single platform string type operation to multiple platform parallel operation, improve expansion efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of river dredging, in particular to a semi-submersible river dredging platform and a dredging method. BACKGROUND

[0002] With the continuous increase of inland river freight volume, it is necessary to dredge the river or build new canals to facilitate the navigation of ships with larger carrying capacity and deeper draft, and to improve the inland waterway grade and navigation capacity. In the field of dredging technology, the cutter suction dredger is the most commonly used work ship. Small cutter suction dredgers can only be used for silt or sandy riverbed excavation. For hard rock riverbed, large cutter suction dredgers are needed. The large cutter suction dredger relies on the rope anchor on both sides to pull the ship body to rotate around the fixed pile for horizontal sweeping excavation, which requires a large water width. In the inland river operation with limited width, it often affects the river navigation. The existing river dredging method for hard rock riverbed is underwater drilling and blasting. With the increasing strictness of environmental protection requirements, this method is gradually being restricted. Based on the principles of impact, milling, dense drilling + strong digging, new non-explosive excavation ships such as heavy hammer impact ship, high-frequency breaking ship, milling ship, backhoe dredger, etc. have emerged, and have been used in Xijiang River Basin, Pinglu Canal and other projects. The backhoe dredger itself does not have the ability to directly break hard rock and needs to be combined with dense drilling to process the riverbed into a honeycomb shape to increase the broken rock air face, so as to excavate the riverbed. The other ship types only have excavation capacity and need to be matched with a grab ship for slag removal, which is a complex process. The above-mentioned ship types generally have the problems of discontinuous operation, complex process and low excavation efficiency. SUMMARY

[0003] The present application aims to provide a semi-submersible river dredging platform and a dredging method to solve the technical problems of discontinuous operation, complex process and low excavation efficiency of the existing river dredging ship type. The specific technical solutions are as follows:

[0004] The present application provides a semi-submersible river dredging platform, comprising: a semi-submersible platform provided with a mounting hole; a winch mechanism, a first end of the winch mechanism being connected to the semi-submersible platform, a second end of the winch mechanism extending into the mounting hole; a dredging device, the dredging device comprising a milling arm, a rotating unit, a support arm, a slurry discharge assembly and a swing driving member, a first end of the support arm being slidingly connected to the hole wall of the mounting hole, the second end of the winch mechanism being connected to the support arm, the rotating unit being connected to a second end of the support arm, the milling arm being connected to the rotating unit, the swing driving member being connected between the milling arm and the rotating unit, the slurry discharge assembly being mounted on the milling arm; an embedded pile positioning mechanism, the embedded pile positioning mechanism comprising a drilling frame, a pile lifting assembly and a fixed pile, the drilling frame being fixed to the semi-submersible platform, the fixed pile extending into the riverbed through the semi-submersible platform, the pile lifting assembly being connected between the drilling frame and the fixed pile.

[0005] The further improvement of the semi-submersible river channel dredging platform is that the semi-submersible platform comprises an upper platform, an intermediate column and a floating box, the intermediate column is connected between the upper platform and the floating box, and the mounting hole is arranged on the upper platform.

[0006] The further improvement of the semi-submersible river channel dredging platform is that the top of the upper platform is provided with a power head for driving the fixed pile to rotate.

[0007] The further improvement of the semi-submersible river channel dredging platform is that the bottom of the upper platform is provided with a stabilizing disc for locking the fixed pile.

[0008] The further improvement of the semi-submersible river channel dredging platform is that the pile lifting assembly comprises a pile lifting winch and a pulley, the pile lifting winch is installed on the first side of the drilling frame, the fixed pile is located on the second side of the drilling frame, the pulley is installed on the top of the drilling frame, and the winch rope of the pile lifting winch is wound on the drilling frame and connected to the fixed pile.

[0009] The further improvement of the semi-submersible river channel dredging platform is that the top of the fixed pile is provided with a pusher for pushing the fixed pile to impact downward, and the winch rope of the pile lifting winch is connected to the pusher.

[0010] The further improvement of the semi-submersible river channel dredging platform is that the bottom of the fixed pile is provided with an expander for tightly pressing the hole wall of the pile hole, and the expander comprises an expander driving member and an expander block, and the expander driving member is connected between the fixed pile and the expander block.

[0011] The further improvement of the semi-submersible river channel dredging platform is that the bottom of the expander is provided with a down-the-hole hammer for breaking rocks.

[0012] The further improvement of the semi-submersible river channel dredging platform is that a sliding groove is arranged on the hole wall of the mounting hole, the first end of the support arm is provided with a bracing device, the bracing device comprises a bracing driving member and a bracing shoe, the first end of the bracing driving member is connected to the first end of the support arm, the second end of the bracing driving member is connected to the bracing shoe, and the bracing shoe is slidingly connected in the sliding groove.

[0013] The application also provides a dredging method using the semi-submersible river channel dredging platform, which combines N sequence holes into a rectangular dredging area through S-shaped displacement, and specifically comprises the following steps:

[0014] S1, using external equipment, the platform is dragged to the rectangular dredging area;

[0015] S2, lowering the fixed pile (405) through the pile lifting assembly, so that the bottom of the fixed pile (405) contacts the riverbed (11), increases the weight of the semi-submersible platform (1), and applies a rock-breaking pressure to the fixed pile (405), so that the fixed pile (405) drills downward into the riverbed (11);

[0016] S3, adjusting the winch mechanism (2), lowering the dredging device (3) to the starting height, supporting the arm (303) to the hole wall of the mounting hole (104), and excavating, specifically comprising:

[0017] S3.1, starting the i-th hole j-th layer excavation to a predetermined depth, i is a natural number greater than or equal to 1 and less than or equal to N, and j is a natural number greater than or equal to 1;

[0018] S3.2, judging whether the i-th hole excavation reaches the designed dredging depth, if yes, entering S4, otherwise, entering the next step;

[0019] S3.3, taking j=j+1, lowering the dredging device (3) by an equal distance through the adjustment of the winch mechanism (2), and returning to S3.1;

[0020] S4, making a judgment, if i is greater than N, the excavation of all holes is completed; if i is less than N, taking i=i+1, pulling out the fixed pile (405) from the pile hole (10) through the pile lifting assembly, and dragging the semi-submersible platform (1) to the i-th hole by using external equipment, and returning to step S2;

[0021] S5, completing the entire river channel area dredging.

[0022] The technical scheme of the present application has the following beneficial effects:

[0023] The semi-submersible river channel dredging platform can realize synchronous excavation and slagging through the milling arm provided with the slurry discharging assembly, and has higher efficiency than the traditional impact breaking dredging ship. The semi-submersible platform can be designed in a modular manner, and through platform expansion combination, single-platform serial operation can be changed to multi-platform parallel operation, thereby improving the dredging efficiency and solving the technical problems of the existing river channel dredging ship, such as discontinuous operation, complex process and low excavation efficiency. The pile positioning mechanism capable of automatically entering rock is provided, so that the counterforce problem during hard rock excavation is solved, and the downward milling method is adopted, so that compared with the traditional horizontal sweeping type excavation of the cutter suction ship, the side anchor rope is not needed, the river channel occupation is small, and the navigation is not affected.

[0024] In addition to the purposes, features and advantages described above, the present application has other purposes, features and advantages. The present application will be further described below with reference to the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 This is a front view of the semi-submersible river widening platform of the present invention (A is the direction of water flow);

[0027] Figure 2 This is a side view of the semi-submersible river widening platform of the present invention (B indicates the water flow direction).

[0028] Figure 3 This is a top view of the semi-submersible river widening platform (two sets of fixed piles) of the semi-submersible river widening platform of the present invention.

[0029] Figure 4 This is a top view of the semi-submersible river widening platform (four sets of fixed piles) of the present invention.

[0030] Figure 5 This is a perspective view of the semi-submersible platform of the semi-submersible river widening platform of the present invention.

[0031] Figure 6 This is a schematic diagram of the embedded pile positioning mechanism of the semi-submersible river widening platform of the present invention.

[0032] Figure 7 yes Figure 4 A magnified view of the C-ring;

[0033] Figure 8 yes Figure 6 A magnified view of the middle D circle;

[0034] Figure 9 This is a single-platform serial operation route diagram of the semi-submersible river widening method of the present invention (E is the operation area, F is the navigation area);

[0035] Figure 10 This is a single-platform parallel operation route diagram of the semi-submersible river widening method of the present invention (E is the operation area, F is the navigation area);

[0036] Figure 11 This is a schematic diagram of the circular outline excavation of the semi-submersible river channel widening method of the present invention;

[0037] Figure 12 This is a schematic diagram of the rectangular outline excavation of the semi-submersible river channel widening method of the present invention.

[0038] Among them, 1. Semi-submersible platform; 101. Upper platform; 102. Intermediate column; 103. Floating box; 104. Mounting hole; 105. Slide chute; 2. Winch mechanism; 3. Excavation device; 301. Milling arm; 302. Rotary unit; 303. Support arm; 304. Slurry pump; 305. Slurry pipe; 306. Swing drive; 307. Tensioning device; 3071. Tensioning drive; 3072. Support shoe; 4. Embedded pile body. Positioning mechanism; 401, pulley; 402, drill frame; 403, pile lifting winch; 404, pusher; 405, fixed pile; 406, power head; 407, stabilizing plate; 408, tensioner; 4081, tensioning drive component; 4082, tensioning block; 409, down-the-hole hammer; 5, mud-water separation system; 6, control center; 7, electro-hydraulic system; 8, generator set; 9, excavation outline; 10, pile hole; 11, riverbed; 12, mud barge. Detailed Implementation

[0039] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] See Figures 1-12 As shown, a semi-submersible river widening platform includes: a semi-submersible platform 1 with a mounting hole 104; a winch mechanism 2, the first end of which is connected to the semi-submersible platform 1, and the second end of which extends into the mounting hole 104; and a widening device 3, which includes a milling arm 301, a rotating unit 302, a support arm 303, a slurry discharge assembly, and a swing drive 306. The first end of the support arm 303 is slidably connected to the wall of the mounting hole 104, and the second end of the winch mechanism 2 is connected to the support arm 303. Unit 302 is connected to the second end of the support arm 303, the milling arm 301 is connected to the rotary unit 302, the swing drive 306 is connected between the milling arm 301 and the rotary unit 302, and the slurry discharge assembly is installed on the milling arm 301; the embedded pile positioning mechanism 4 includes a drill frame 402, a pile lifting assembly and a fixed pile 405, the drill frame 402 is fixed on the semi-submersible platform 1, the fixed pile 405 passes through the semi-submersible platform 1 and extends into the riverbed 11, and the pile lifting assembly is connected between the drill frame 402 and the fixed pile 405.

[0041] Specifically, such as Figure 4 and Figure 5 As shown, the number of winch mechanisms 2 is at least three, and the at least three winch mechanisms 2 are evenly distributed circumferentially around the outer periphery of the mounting hole 104. The number of embedded pile positioning mechanisms 4 is at least two, and the at least two winch mechanisms 2 are evenly distributed circumferentially at the edge of the semi-submersible platform 1. In this embodiment, the number of both the winch mechanisms 2 and the embedded pile positioning mechanisms 4 is four.

[0042] The semi-submersible river widening platform also includes a slurry separation system 5, a control center 6, an electro-hydraulic system 7, and a generator set 8, with connections made according to existing technology. The slurry discharge assembly includes a slurry pump 304 and a slurry pipe 305, which discharges the excavated excavated soil in a mixed form to the slurry separation system 5 on the platform, and then the slurry separation system 5 discharges it to the mud barge 12 for removal, achieving simultaneous excavation, slag discharge, and slag-water separation. The generator set 8 provides power for the widening operation. The widening device 3 is suspended from the mounting hole 104 by a winch mechanism 2 on the upper part of the platform. After excavation to a certain depth, the widening device 3 can be lowered via the winch mechanism 2, completing slag discharge and slag-water separation operations simultaneously with excavation. The embedded pile positioning mechanism 4 can automatically embed the fixed pile 405 into the riverbed 11 rock mass, firmly fixing the platform on the riverbed 11. The reaction force generated during milling by the widening device 3 is transmitted to the semi-submersible platform 1 through the tensioning device 307 on the support arm 303.

[0043] The swing drive 306 can be a linear drive such as a hydraulic cylinder, pneumatic cylinder, or electric drive. In this embodiment, the swing drive 306 is a hydraulic cylinder. The milling arm 301 performs swing milling under the drive of the swing hydraulic cylinder and rotates around the vertical axis under the drive of the rotary unit 302 to form a circular excavation profile 9 (e.g., ...). Figure 11 As shown), after excavating to a certain depth, the widening device 3 is lowered using the winch mechanism 2 to complete the step change. When the widening device 3 adopts constant radius excavation, its excavation outline 9 is circular, preferably, as shown... Figure 12 As shown, when the milling arm 301 adopts non-uniform radius excavation, it can conform to a rectangular outline. Compared with a circular outline, the rectangular outline has a smaller repeated excavation area, which can improve the excavation efficiency. Optionally, the excavation device 3 can also realize rectangular outline excavation through a track-type translation mechanism.

[0044] This invention enables the deepening and widening of inland waterways through a combination of downward excavation and relocation operations. It combines the advantages of simultaneous excavation and slag removal by a cutter suction dredger with the minimal waterway occupancy of an inland dredger, making it particularly suitable for widening hard riverbeds in inland waterways with limited water area. Furthermore, the platform's modular expansion capabilities significantly improve the efficiency of inland waterway widening.

[0045] Preferred, such as Figure 3 As shown, the semi-submersible platform 1 includes an upper platform 101, an intermediate column 102, and a pontoon 103. The intermediate column 102 connects the upper platform 101 and the pontoon 103, and the mounting hole 104 is provided on the upper platform 101. The pontoon 103 has a hollow structure, and the buoyancy of the entire semi-submersible platform 1 is controlled by adjusting the amount of water stored inside, ensuring the stability of the semi-submersible platform 1 during relocation and ensuring that the semi-submersible platform 1 does not submerge.

[0046] Preferred, such asFigure 6 As shown, the top of the upper platform 101 is provided with a power head 406 for driving the fixed pile 405 to rotate. In the embodiment, the fixed pile 405 can be a steel pile. The bottom of the upper platform 101 is provided with a stabilizing disc 407 for locking the fixed pile 405. The pile lifting assembly includes a pile lifting winch 403 installed on the first side of the drilling frame 402, the fixed pile 405 located on the second side of the drilling frame 402, and a pulley 401 installed on the top of the drilling frame 402, with the winch rope of the pile lifting winch 403 connected to the fixed pile 405 after winding around the drilling frame 402. To ensure a certain space for movement on both sides of the drilling frame 402, the top of the drilling frame 402 is provided in a Y shape, and the pulley 401 is arranged on both sides, so as to facilitate the winding of the winch rope of the pile lifting winch 403. The winch rope of the pile lifting winch 403 is generally a steel wire rope.

[0047] Preferably, the top of the fixed pile 405 is provided with a pusher 404 for pushing the fixed pile 405 to impact downward, and the winch rope of the pile lifting winch 403 is connected to the pusher 404. As shown, Figure 8 As shown, the bottom of the fixed pile 405 is provided with an expander 408 for pressing against the hole wall of the pile hole 10, which includes an expansion driving member 4081 and an expansion block 4082, with the expansion driving member 4081 connected between the fixed pile 405 and the expansion block 4082. The bottom of the expander 408 is provided with a down-the-hole hammer 409 for breaking rock. The expansion driving member 4081 can be a linear driving member such as an oil cylinder, an air cylinder or an electric driving member. In the embodiment, the expansion driving member 4081 is an oil cylinder. Before excavation, the floating box 103 is adjusted to have a floating force, so that the down-the-hole hammer 409 contacts the rock surface of the riverbed 11 and applies a certain pressure. The down-the-hole hammer 409 impacts downward to break rock and rotates under the driving of the power head 406. The pusher 404 pushes the fixed pile 405 to continue to impact downward to form a pile hole 10 with a certain depth, and the expansion driving member 4081 extends to tightly press the expansion block 4082 against the hole wall of the pile hole 10. The fixed pile 405 has the characteristics of a drill rod and a positioning pile, can drive the down-the-hole hammer 409 to rotate under the driving of the power head 406, and is used to bear the expansion resistance force from the platform after the expansion of the expander 408. The number of fixed piles 405 can be two groups or more. The down-the-hole hammer 409 can be replaced by a screw drill bit or other common hard rock drill bit as needed. The fixed pile 405 can also use a pile gripper or other equipment to clamp the steel pile with a hydraulic oil cylinder to pull out the pile hole 10.

[0048] Preferably, as shown, Figure 7As shown, the hole wall of the mounting hole 104 is provided with a sliding groove 105, the first end of the support arm 303 is provided with a bracing device 307, the bracing device 307 comprises a bracing driving member 3071 and a bracing shoe 3072, the first end of the bracing driving member 3071 is connected to the first end of the support arm 303, the second end of the bracing driving member 3071 is connected to the bracing shoe 3072, and the bracing shoe 3072 is slidingly connected in the sliding groove 105. The overbreak device 3 can slide up and down along the sliding groove 105 through the bracing shoe 3072. Under the driving of the bracing oil cylinder, the bracing shoe 3072 braces the sliding groove 105, and the reaction force of the milling arm 301 during excavation is transmitted to the semi-submersible platform 1 through the bracing device 307 of the support arm 303 and the sliding groove 105.

[0049] The application also provides an overbreak method using the semi-submersible river overbreak platform. First, the platform is fixed to the bedrock of the riverbed 11 by using the down-the-hole hammer 409 to drill holes, and then the overbreak device 3 is used to excavate downward while separating the rock debris on the platform. After excavating to the designed depth, the platform is horizontally displaced and the above-mentioned positioning and overbreak steps are repeated to realize the overbreak and deepening of the entire river. The semi-submersible river overbreak platform provided by the application has the advantages of firm positioning, synchronous overbreak and debris removal, parallel operation through platform module parallel connection, S-shaped displacement or parallel straight-line displacement overbreak, improved overbreak efficiency, small river occupation compared with traditional cutter suction dredgers, and no influence on river navigation. N serial holes are combined into a rectangular overbreak area through S-shaped displacement, and the specific steps are as follows:

[0050] S1, using external equipment (such as a tugboat) to tow the platform to the rectangular overbreak area, such as position ①;

[0051] S2, by lowering the pile assembly, the fixed pile 405 is contacted with the riverbed 11, water is injected into the floating box 103 to increase the weight of the platform, and the rock breaking pressure of the down-the-hole hammer 409 is increased; the down-the-hole hammer 409 impacts downward to break the rock, the pusher 404 pushes the steel pile to drill a pile hole 10 to a certain depth, and the depth of the pile hole 10 meets the entering of the expander 408 into the rock mass;

[0052] S3, the expander 408 expands the pile hole 10, the stabilizing disc 407 on the bottom of the platform 101 locks the steel pile, the winch mechanism 2 is adjusted, the overbreak device 3 is lowered to the starting height, the support arm 303 is braced to the hole wall of the mounting hole 104, and excavation is performed, which has the following steps:

[0053] S3.1, start excavating the i-th sequence hole to the predetermined depth, i is a natural number greater than or equal to 1 and less than or equal to N (N is 9 in the embodiment), and j is a natural number greater than or equal to 1; in the embodiment, the first layer of the first sequence hole is started to be excavated, and when excavated to the predetermined depth, the expansion device 3 is lowered by an equal distance through the adjustment of the winch mechanism 2, and the second layer is opened, and the cycle of excavation and lowering is repeated, until the first sequence hole is excavated to the designed expansion depth, as shown in Figure 9

[0054] S3.2, determine whether the i-th sequence hole reaches the designed expansion depth, if yes, go to S4, otherwise, go to the next step;

[0055] S3.3, j = j + 1, the expansion device 3 is lowered by an equal distance through the adjustment of the winch mechanism 2, and return to S3.1;

[0056] S4, make a determination, if i is greater than N, the excavation of all holes is completed; if i is less than N, take i = i + 1, the expander 408 is loosened, the steel pile is pulled out of the pile hole 10 through the pile hoist 403, and the semi-submersible platform 1 is towed to the i-th sequence hole (for example, the second sequence hole) by using external equipment (for example, a tugboat), and returns to step S2;

[0057] S5, in the embodiment, the first sequence hole to the ninth sequence hole are combined into the rectangular expansion area (length L x width W), and the entire river channel area expansion is completed.

[0058] As shown in Figure 10 , in step S5, a plurality of platforms can also be connected in parallel, and the first group of platforms is shifted from 1-1 to 1-3, the second group of platforms is shifted from 2-1 to 2-3, and the third group of platforms is shifted from 3-1 to 3-3, in theory, this parallel operation scheme can improve the expansion efficiency by M times, and the number of M is equal to the number of platforms.

[0059] The semi-submersible river channel expansion platform can realize synchronous excavation and deslagging through the milling arm 301 provided with the slurry discharge assembly, and has higher efficiency than the traditional impact crushing dredger; the semi-submersible platform 1 can be designed in a modular manner, and through platform expansion combination, single-platform series operation can be changed to multi-platform parallel operation, so as to improve the expansion efficiency and solve the technical problems of the existing river channel expansion ship type, such as discontinuous operation, complex process and low excavation efficiency. The pile positioning mechanism capable of automatically entering rock is provided, so as to solve the reaction force problem during hard rock excavation, and the downward milling and excavation mode is adopted, compared with the traditional cutter suction dredger sweeping type excavation, the side anchor rope is not needed to be set, the river channel occupation is small, and the navigation is not affected.

[0060] ​The above merely provides the preferred embodiments of the present application, and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the principles and technical scope of the present application shall fall into the scope of the present application.

Claims

1. A semi-submersible river channel enlargement platform, characterized in that, include: A semi-submersible platform (1) is provided with mounting holes (104). A winch mechanism (2), the first end of which is connected to the semi-submersible platform (1), and the second end of which extends into the mounting hole (104); The excavation device (3) includes a milling arm (301), a rotary unit (302), a support arm (303), a slurry discharge assembly, and a swing drive (306). The first end of the support arm (303) is slidably connected to the wall of the mounting hole (104). The second end of the winch mechanism (2) is connected to the support arm (303). The rotary unit (302) is connected to the second end of the support arm (303). The milling arm (301) is connected to the rotary unit (302). The swing drive (306) is connected between the milling arm (301) and the rotary unit (302). The slurry discharge assembly is installed on the milling arm (301). An embedded pile positioning mechanism (4) includes a drill frame (402), a pile lifting assembly, and a fixed pile (405). The drill frame (402) is fixed on the semi-submersible platform (1), and the fixed pile (405) extends through the semi-submersible platform (1) into the riverbed (11). The pile lifting assembly is connected between the drill frame (402) and the fixed pile (405). The pile lifting assembly includes a pile lifting winch (403) and a pulley (401). The pile lifting winch (403) is installed on the first side of the drill frame (402), and the fixed pile (405) is located on the second side of the drill frame (402). The pulley (401) is installed on the top of the drill frame (402), and the winch rope of the pile lifting winch (403) is wound around the drill frame (402) and then connected to the fixed pile (405). The top of the fixed pile (405) is provided with a pusher (404) for pushing the fixed pile (405) downward to impact, and the winch rope of the pile lifting winch (403) is connected to the pusher (404). The bottom of the fixed pile (405) is provided with an expansion device (408) for tightening the wall of the pile hole (10). The expansion device (408) includes an expansion drive (4081) and an expansion block (4082). The expansion drive (4081) is connected between the fixed pile (405) and the expansion block (4082).

2. The semi-submersible river channel enlargement platform according to claim 1, characterized in that, The semi-submersible platform (1) includes an upper platform (101), an intermediate column (102) and a pontoon (103). The intermediate column (102) is connected between the upper platform (101) and the pontoon (103). The mounting hole (104) is provided on the upper platform (101).

3. The semi-submersible river channel enlargement platform according to claim 2, characterized in that, The top of the upper platform (101) is provided with a power head (406) for driving the fixed pile (405) to rotate.

4. The semi-submersible river channel enlargement platform of claim 2, wherein, The bottom of the upper platform (101) is provided with a stabilizing plate (407) for locking the fixing pile (405).

5. The semi-submersible river channel enlargement platform of claim 1, wherein, The bottom of the expander (408) is provided with a down-the-hole hammer (409) for breaking rocks.

6. The semi-submersible riverway expansion platform of claim 1, wherein, The mounting hole (104) is provided with a sliding groove (105) on the hole wall, and the first end of the support arm (303) is provided with a bracing device (307), which comprises a bracing driving member (3071) and a bracing shoe (3072). The first end of the bracing driving member (3071) is connected to the first end of the support arm (303), and the second end of the bracing driving member (3071) is connected to the bracing shoe (3072). The bracing shoe (3072) is slidingly connected in the sliding groove (105).

7. A method of dredging using the semi-submersible river channel dredging platform as claimed in claim 1, characterized in that, N sequential holes are combined into a rectangular expanded area through S-shaped displacement, and the method comprises the following steps: S1, using an external device, the platform is dragged to the rectangular expanded area; S2, the fixed pile (405) is lowered by the pile lifting assembly, so that the bottom of the fixed pile (405) contacts the riverbed (11), the weight of the semi-submersible platform (1) is increased, the rock breaking pressure is applied to the fixed pile (405), and the fixed pile (405) is drilled downward to the riverbed (11); S3, adjust the winch mechanism (2), and lower the expansion device (3) to the starting height, and the support arm (303) is braced to the hole wall of the mounting hole (104), and the excavation is carried out, which comprises the following steps: S3.1, start the i-th sequential hole j-th layer excavation to the predetermined depth, i is a natural number greater than or equal to 1 and less than or equal to N, and j is a natural number greater than or equal to 1; S3.2, determine whether the i-th sequential hole reaches the designed expansion depth, if yes, go to S4, otherwise, go to the next step; S3.3, take j=j+1, lower the expansion device (3) by an equal distance by adjusting the winch mechanism (2), and return to S3.1; S4, if i is greater than N, the excavation of all holes is completed; if i is less than N, take i=i+1, the fixed pile (405) is pulled out of the pile hole (10) by the pile lifting assembly, the semi-submersible platform (1) is dragged to the i-th sequential hole by using an external device, and the step S2 is returned; S5, the entire riverway surface expansion is completed.

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