Combined cutter suction dredger on-water carrying process

Abstract

The invention relates to a combined cutter suction dredger water carrying process, a dredger body of a dredger comprises a main buoyancy tank located at a midship, a steel pile trolley buoyancy tank located at the rear part of the main buoyancy tank, left and right buoyancy tanks located at two sides of the main buoyancy tank, and a duty room and a control room located at the upper part of the main buoyancy tank, the left and right buoyancy tanks are respectively located at the front and rear sides of the main buoyancy tank; the carrying process comprises the following steps of ship dock edge pre-assembly, hoisting point and hoisting form confirmation, pin shaft and trolley steel pile installation and towing berthing. According to the carrying process, the two modules are spliced on the dock side, deck surface equipment is installed in advance, water facing operation is reduced, meanwhile, the two modules are hoisted to the water for pin shaft butt joint, and carrying of the main hull is completed; taking the pin shaft as a boundary when entering water, dividing into two modules and hoisting into water at the same time; in order to reduce the hoisting deformation of the ship body structure, the bow module is implemented in the mode that a box-type process joist is arranged at the bottom of the ship body, the process joist is integrally moved out after entering water, the process joist can prevent the ship body from being stressed, and the deformation of the ship body is controlled to the maximum extent.

Description

Technical Field

[0001] The invention relates to the field of dredgers, and in particular to a water-borne technology for a combined cutter-suction dredger. Background Art

[0002] The rapid development of the global economy in recent decades has promoted the rapid construction of engineering projects such as port development, channel dredging, and land reclamation in various places, making dredgers an indispensable tool for these engineering projects. In view of the small water depth and small engineering volume in a single inland water area, the combined suction dredger came into being. Different from conventional dredgers, the combined dredger is composed of several independent boxes connected together, which can be transported by land between waters that are not accessible by water transportation. At the same time, it greatly facilitates the repair and maintenance of the hull, and can even extend the service life of the ship by replacing damaged boxes.

[0003] At present, the conventional loading method of the existing modular dredger is to load and dock one by one on the water surface in a segmented order, which requires the cooperation of two truck cranes, one of which continuously hangs the main pontoon, and the other hoists and assembles the side pontoon and the trolley pontoon to the main pontoon. If this method is adopted, a 500T gantry crane and a truck crane will be occupied for a long time, which is costly and has a long operation cycle. In addition, the long-term occupation of two hoisting equipment will affect the hoisting operations of other projects in the dock, and there will be many subsequent water operations, which has high safety risks. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a combined cutter suction dredger water-borne loading process which shortens the construction period of the whole ship and improves the utilization rate of the lifting equipment.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: a combined cutter suction dredger water loading process, the hull of the dredger includes a main pontoon located in the middle of the ship, a steel pile trolley pontoon at the rear of the main pontoon, left and right pontoons located on both sides of the main pontoon, a duty room and a control room on the top of the main pontoon, and there are two left and right pontoons respectively, which are located at the front and rear sides of the main pontoon. The innovation lies in that the loading process includes the following steps: S1: Pre-assembly of the hull at the dock; After the construction and painting of each pontoon is completed, it is transported to the outer dock for final assembly and closure. The main pontoon and the left and right pontoons are connected to each other through hooks at the bottom of the ship and bolts at the deck. The main pontoon and the trolley pontoon are connected through pins at the bottom of the ship and the deck. After the machining of each connection device, the pontoon is installed and fixed after the positioning is completed. S2: Confirmation of lifting points and lifting forms; The whole ship is divided into two modules and hoisted into the water. The pin connecting the main pontoon and the trolley pontoon is removed after pre-assembly and installed after the modules are launched into the water. During hoisting, each pontoon needs to be stressed to control the deformation of the hull structure. At the same time, because the modules where the main pontoon and the side pontoon are located are long and the lifting points are relatively scattered, the process joists are arranged at the center of gravity of the module as the main stress point, and then the deck surface product lifting ears are used for auxiliary force leveling. The trolley pontoon module is hoisted using the 8 product lifting ears on the deck surface; S3: Installation of pin shaft and trolley steel pile; After the two modules are hoisted into the water, the pin shaft between the main pontoon and the trolley pontoon is positioned and installed. A hand chain hoist is arranged on the trolley pontoon module in advance for leveling and docking. After the docking is completed, the process joist is sunk 1m and removed towards the bow. After all the rigging is removed and the cables are tied, the positioning trolley steel pile is installed; S4: Towing and berthing; After all the processes are completed, the dredger is towed to the dock by a tugboat for berthing and subsequent electrical and equipment debugging work is carried out.

[0006] Furthermore, in step S1, each pontoon is assembled and closed by hoisting. In order to facilitate the arrangement of the process support beams required for hoisting, the closing dock pier needs to be set to 1.8m high. When closing, the main pontoon is first positioned, and then the four side pontoons on both sides are connected to it, and finally the trolley pontoon is fixed to the stern of the main pontoon.

[0007] Furthermore, the strength of the connection device between the pontoon and the side pontoon is calculated as follows: The main pontoon and the left and right pontoons are connected to each other through hooks at the bottom of the ship and bolts at the deck. There are two sets of connection devices at the bow and stern. The connection device at the deck position is 5 M30 bolts, and the connection device at the bottom of the ship is a hook and round steel connection with a diameter of 80mm. The positions of the two sets of connection devices of the front pontoon are defined as F 1 and F 2 , in the hoisting state, the vertical force F on the two sets of connection devices of the front pontoon V1 and F V2 Calculate according to the following formula: ; ; Where: H — vertical distance between the connection device at the deck and the connection device at the bottom, in m; F G ——weight of the front pontoon, kN; X G ——The distance between the center of gravity of the side buoy and the ship length F 2 Horizontal distance of the connecting device at the location, m; X R ——Horizontal distance between two sets of connection devices of the side buoy, m; The vertical force F acting on the two sets of connection devices Y1 and F Y2 Calculate according to the following formula: ; ; Where: H — vertical distance between the connection device at the deck and the connection device at the bottom, in m; F G ——weight of the side buoy, kN; X G ——Horizontal distance from the center of gravity of the lateral buoy to the connection device at position F2 along the ship length, m; X R ——Horizontal distance between two sets of connection devices of the side buoy, m; Y G ——Horizontal distance between the center of gravity of the lateral buoy and the connecting device along the ship width direction, m; The shear stress τ of the two sets of connection devices should meet the following requirements: ≥ ; Where: F V ——Take the vertical force F V1 and F V2 The calculated value with the larger absolute value is kN; A d ——shearing area of ​​the connection device at the deck, cm 2 ; A b ——shear resistance area of ​​the connection device at the bottom of the ship, cm 2 ; [τ] —— allowable shear stress; The horizontal tensile stress σ of the two sets of connection devices should meet the following calculation requirements: ≤ ; ≤ ; Where: F Y ——Take the vertical force F Y1 and F Y2 The calculated value with the larger absolute value is kN; A——Cross-sectional area of ​​the connection device at the deck or bottom, cm 2 ; [σ] —— allowable normal stress; The composite stress σc of the connection device between the side pontoon and the main pontoon should meet the following calculation requirements: ≥ ; Where: [σc] —— allowable composite stress; The strength check of the connection device between the rear pontoon and the main pontoon is calculated by referring to the above formula.

[0008] Furthermore, the deflection of the main pontoon and the side pontoon modules during hoisting is calculated as follows: Each pontoon is simplified as a box body, without considering the internal reinforcement, and the stern deflection fstern is calculated as follows: W = I / e; M=G 1 *L 1 ; σ=M / W<[σ]; f = G 1 *L 1 3 / 3EI; Where: I——moment of inertia, mm 4 ; e——the distance from the center of gravity to the bottom plate, mm; W——bending section coefficient, mm 3 ; M ——bending moment, N / mm²; [σ]——allowable normal stress, MPa; f——deflection, mm; The bow deflection fb is calculated as follows: M=G 2 *L 2 ; σ=M / W<[σ] fb = G 2 *L 2 3 / 3EI.

[0009] The advantages of the present invention are as follows: the loading process of the present invention adopts the method of assembling two modules at the dock side, installing deck surface equipment in advance, reducing water operations, and hoisting to the water for pin docking to complete the loading of the main hull; when launching, the pin is used as the dividing line, and the module is divided into two modules and hoisted into the water at the same time; in order to reduce the hoisting deformation of the hull structure, the bow module adopts a box-type process joist at the bottom of the hull, and the process joist is moved out as a whole after launching. The process joist can avoid the hull from being stressed and control the hull deformation to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is the arrangement diagram of the dock pier and the hanging beam bracket in the present invention.

[0011] Figure 2 It is a schematic diagram of the main buoyancy tank connection device in the present invention.

[0012] Figure 3 It is a schematic diagram of the side buoyancy box connection device of the present invention.

[0013] Figure 4 It is a schematic diagram of the bottom hook connection in the present invention.

[0014] Figure 5 It is a schematic diagram of the configuration of the sling in the present invention.

[0015] Figure 6 It is a schematic diagram of the force of the hull hoisting in the present invention. DETAILED DESCRIPTION

[0016] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation mode, structure, characteristics and effects of the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0017] The hull of the dredger includes a main pontoon 2 located amidships, a steel pile trolley pontoon 4 at the rear of the main pontoon 2, left and right pontoons 3 located on both sides of the main pontoon, a duty room and a control room on the top of the main pontoon 2, and there are two left and right pontoons 3, respectively located at the front and rear sides of the main pontoon 2.

[0018] Combine the following Figure 1-Figure 6 The combined cutter suction dredger water loading process of the present invention is specifically described as follows: S1: Pre-assembly of the hull at the dock; After the construction and painting of each pontoon is completed, it is transported to the outer dock for final assembly and closure. In order to facilitate the arrangement of the process support beams 5 required for lifting, the closure dock pier 1 needs to be set 1.8m high. When closing, first use the main pontoon 2 for positioning, then connect the four side pontoons 3 on both sides to the main pontoon 2, and finally fix the trolley pontoon 4 to the stern of the main pontoon 2.

[0019] The main pontoon 2 and the left and right pontoons 3 are connected to each other through hooks at the bottom of the ship and bolts at the deck. The main pontoon 2 and the trolley pontoon 4 are connected through pins at the bottom of the ship and at the deck. After each connecting device is machined, it is installed and fixed after the pontoon is positioned.

[0020] S2: Confirmation of lifting points and lifting forms; The whole ship is divided into two modules and hoisted into water. The main pontoon 2 and the left and right pontoons 3 are hoisted as bow modules, and the trolley pontoon 4 is hoisted as a trolley pontoon module.

[0021] The pin connecting the main pontoon and the trolley pontoon is removed after pre-assembly and installed after being launched into the water. Each pontoon needs to be stressed during hoisting to control the deformation of the hull structure. At the same time, in order to reduce the workload of installation and disassembly of the lifting lugs, the use of product lifting lugs was considered during the scheme planning. However, since the module where the main pontoon and the side pontoon are located is relatively long and the lifting points are relatively scattered, it was finally decided to arrange the process support beam 5 at the center of gravity of the module as the main stress point, and then use the product lifting lugs on the deck surface for auxiliary force leveling. The trolley pontoon module is hoisted using the 8 product lifting lugs on the deck surface.

[0022] The main pontoon and side pontoon modules weigh 198 tons, and the stern of the lifting beam is G 1 =65T, bow of lifting beam G 2 =48T, hanging beam area 85T, such as Figure 6 As shown, the main material of the ship plate is Grade A ship plate, and the elastic modulus is E=206GPa.

[0023] The strength of the connection device between the main pontoon and the side pontoon is calculated as follows: The main pontoon and the left and right pontoons are connected to each other through hooks at the bottom of the ship and bolts at the deck. There are two sets of connection devices at the bow and stern. The connection device at the deck position is 5 M30 bolts, and the connection device at the bottom of the ship is a hook and round steel connection with a diameter of 80mm. The positions of the two sets of connection devices of the front pontoon are defined as F 1 and F 2 , in the hoisting state, the vertical force F on the two sets of connection devices of the front pontoon V1 and F V2 Calculate according to the following formula: =-757.2kN; =450.7kN Where: F G ——weight of the front pontoon, kN; X G ——The distance between the center of gravity of the side buoy and the ship length F 2 Horizontal distance of the location connection device, m; X R ——Horizontal distance between the two sets of connection devices of the side pontoon (between the F1 position and the F2 position), m.

[0024] Calculate based on the weight center of gravity of the front pontoon: F G =306.5kN, X G =10.45m x R =4.23m.

[0025] The vertical force F acting on the two sets of connection devices Y1 and FY2 Calculate according to the following formula: =301.7kN; =179.6kN; Where: H — vertical distance between the connection device at the deck and the connection device at the bottom, in m; F G ——weight of the side buoy, kN; X G ——Horizontal distance from the center of gravity of the lateral buoy to the connection device at position F2 along the ship length, m; X R ——Horizontal distance between the two sets of connection devices of the side pontoon (between the F1 position and the F2 position), m.

[0026] Y G ——Horizontal distance between the center of gravity of the buoy and the connecting device along the ship width direction, m.

[0027] According to the weight center of the front pontoon, we can calculate: H=1.97m, F G =306.5kN X G =10.45m x R =4.23mY G =0.785m.

[0028] The shear stress τ of the two sets of connection devices should meet the following requirements: =88.5N / mm 2 ≥ Not meeting the requirements; Value: F V1 =757.2kN, A d =35.33cm 2 , Ab=50.24cm 2 , [τ]=50N / mm 2 .

[0029] Where: F V ——Take the vertical force F V1 and F V2 The calculated value with the larger absolute value is kN; A d ——shearing area of ​​the connection device at the deck, cm 2 ; A b ——shear resistance area of ​​the connection device at the bottom of the ship, cm 2 ; [τ] ——allowable shear stress.

[0030] The horizontal tensile stress σ of the two sets of connection devices should meet the following calculation requirements: =85.4N / mm 2 ≤ =60.1N / mm 2 ≤ Value: F Y2 =301.7kN, A d =35.33cm 2 , A b =50.24cm 2 , [σ]=90N / mm 2 .

[0031] Where: F Y ——Take the vertical force F Y1 and F Y2 The calculated value with the larger absolute value is kN; A——Cross-sectional area of ​​the connection device at the deck or bottom, cm 2 ; [σ] ——allowable normal stress.

[0032] The composite stress σc of the connection device between the side pontoon and the main pontoon should meet the following calculation requirements: =196.5N / mm2≥ Not meeting requirements Value: σ=85.4N / mm 2 , τ=88.5N / mm 2 , [σc]=110N / mm 2 .

[0033] Where: σ —— horizontal tensile stress σ of the above two sets of connection devices; τ —— shear stress τ of the above two sets of connection devices; [σc] ——allowable composite stress.

[0034] The strength check of the connection device between the rear pontoon 3 and the main pontoon 2 is calculated by referring to the above formula.

[0035] According to the calculation results, when the modules where the main pontoon 2 and the side pontoon 3 are located are hoisted, if only the main pontoon 2 is hoisted, the vertical shear force of each connection device does not meet the hoisting requirements. In order to reduce the force of each connection device, a hoisting point should be set on each pontoon, such as Figure 5As shown, considering the number of lifting ears and the complexity of the lifting rigging configuration, the design process joist is arranged at the center of gravity of the bottom of this module, and simultaneously supports the main pontoon 2 and the side pontoon 3 for lifting.

[0036] The deflection of the modules where the main pontoon 2 and the side pontoon 3 are located during hoisting is calculated as follows: Each pontoon is simplified as a box body, without considering the internal reinforcement, and the stern deflection fstern is calculated as follows: W=I / e=1.4*108mm 3 ; M=G 1 *L 1 =3.25*109N / mm 2 ; σ=M / W=23.2MPa<[σ]=255MPa; f = G 1 *L 1 3 / 3EI=0.6mm<4 / 1000=20mm meets the requirements Value: L 1 =5m, G 1 =65T, I=2.1*1011mm 4 , e=1500mm, [σ]=255MPa.

[0037] Where: I——moment of inertia, mm 4 ; e——the distance from the center of gravity to the bottom plate, mm; W——bending section coefficient, mm 3 ; M ——bending moment, N / mm²; [σ]——allowable normal stress, MPa; f——deflection, mm.

[0038] The bow deflection fb is calculated as follows: W=5*107mm 3 ; M=G 2 *L 2 =4.2*109N / mm 2 ; σ=M / W=84MPa<[σ]=255MPa; fb = G 2 *L 2 3 / 3EI=10.2mm<4 / 1000=34.8mm meets the requirements Value: L 2 =8.7m, G 2=48T, I=5*1010mm 4 .

[0039] According to the calculation results, when the modules of the main pontoon 2 and the side pontoon 3 are hoisted using process joists, the hull structure strength meets the requirements. In order to further reduce the deformation of the structure and protect the connection devices between the pontoons, slings are hung at the positions with larger bending moments on both sides of the bow and stern to assist in force bearing and leveling.

[0040] S3: Installation of pin shaft and trolley steel pile; After the two modules are hoisted into the water, the pin shaft between the main pontoon and the trolley pontoon is positioned and installed, and a hand winch is arranged on the trolley pontoon module in advance for leveling and docking. After the docking is completed, the process support beam is sunk 1m and removed towards the bow. After all the lifting rigging is removed and the cables are tied, the positioning trolley steel piles are installed.

[0041] S4: Towing and berthing; After all the processes are completed, the dredger is towed to the dock by a tugboat for berthing and subsequent electrical and equipment debugging work is carried out.

[0042] The loading process of the present invention is to assemble two modules at the dockside, install deck equipment in advance to reduce water operations, and hoist them to the water for pin docking to complete the loading of the main hull; when launching, the module is divided into two modules with the pin as the dividing line and hoisted into the water at the same time; in order to reduce the deformation of the hull structure during hoisting, the bow module adopts a box-type process joist at the bottom of the hull, and the process joist is moved out as a whole after launching. The process joist can avoid the hull from being stressed and control the hull deformation to the greatest extent.

[0043] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A combined cutter suction dredger water-borne process, the hull of the dredger includes a main pontoon located in the middle of the ship, a steel pile trolley pontoon at the rear of the main pontoon, left and right pontoons located on both sides of the main pontoon, a duty room and a control room on the top of the main pontoon, two left and two right pontoons each, located at the front and rear sides of the main pontoon respectively, characterized in that: The mounting process includes the following steps: S1: Pre-assembly of the hull at the dock; After the construction and painting of each pontoon is completed, it is transported to the outer dock for final assembly and closure. The main pontoon and the left and right pontoons are connected to each other through hooks at the bottom of the ship and bolts at the deck. The main pontoon and the trolley pontoon are connected through pins at the bottom of the ship and the deck. After the machining of each connection device, the pontoon is installed and fixed after the positioning is completed. S2: Confirmation of lifting points and lifting forms; The whole ship is divided into two modules and hoisted into the water. The pin connecting the main pontoon and the trolley pontoon is removed after pre-assembly and installed after the modules are launched into the water. During hoisting, each pontoon needs to be stressed to control the deformation of the hull structure. At the same time, because the modules where the main pontoon and the side pontoon are located are long and the lifting points are relatively scattered, the process joists are arranged at the center of gravity of the module as the main stress point, and then the deck surface product lifting ears are used for auxiliary force leveling. The trolley pontoon module is hoisted using the 8 product lifting ears on the deck surface; S3: Installation of pin shaft and trolley steel pile; After the two modules are hoisted into the water, the pin shaft between the main pontoon and the trolley pontoon is positioned and installed. A hand chain hoist is arranged on the trolley pontoon module in advance for leveling and docking. After the docking is completed, the process joist is sunk 1m and removed towards the bow. After all the rigging is removed and the cables are tied, the positioning trolley steel pile is installed; S4: Towing and berthing; After all the processes are completed, the dredger is towed to the dock by a tugboat for berthing and subsequent electrical and equipment debugging work is carried out.

2. The combined cutter suction dredger water-borne process according to claim 1, characterized in that: In step S1, each pontoon is assembled and closed by hoisting. In order to facilitate the arrangement of the process support beams required for hoisting, the closing dock pier needs to be set to 1.8m high. When closing, the main pontoon is first positioned, and then the four side pontoons on both sides are connected to it, and finally the trolley pontoon is fixed to the stern of the main pontoon.

3. The combined cutter suction dredger water-borne process according to claim 1 is characterized in that: The strength of the connection device between the pontoon and the side pontoon is calculated as follows: The main pontoon and the left and right pontoons are connected to each other through hooks at the bottom of the ship and bolts at the deck. There are two sets of connection devices at the bow and stern. The connection device at the deck position is 5 M30 bolts, and the connection device at the bottom of the ship is a hook and round steel connection with a diameter of 80mm. The positions of the two sets of connection devices of the front pontoon are defined as F1 and F2 respectively. In the hoisting state, the vertical force F V1 and F V2 Calculate according to the following formula: ； ； Where: H — vertical distance between the connection device at the deck and the connection device at the bottom, in m; F G ——weight of the front pontoon, kN; X G - horizontal distance from the center of gravity of the wing buoy to the connection device at position F2 along the ship length, m; X R ——Horizontal distance between two sets of connection devices of the side pontoon, m; The vertical force F on the two sets of connection devices Y1 and F Y2 Calculate according to the following formula: ； ； Where: H — vertical distance between the connection device at the deck and the connection device at the bottom, in m; F G ——weight of the side buoy, kN; X G ——Horizontal distance from the center of gravity of the lateral buoy to the connection device at position F2 along the ship length, m; X R ——Horizontal distance between two sets of connection devices of the side pontoon, m; Y G ——Horizontal distance between the center of gravity of the lateral buoy and the connecting device along the ship width direction, m; The shear stress τ of the two sets of connection devices should meet the following requirements: ≥ ； Where: F V ——Take the vertical force F V1 and F V2 The calculated value with the larger absolute value is kN; A d ——shearing area of ​​the connection device at the deck, cm 2 ; A b ——shear resistance area of ​​the connection device at the bottom of the ship, cm 2 ; [τ] —— allowable shear stress; The horizontal tensile stress σ of the two sets of connection devices should meet the following calculation requirements: ≤ ； ≤ ； Where: F Y ——Take the vertical force F Y1 and F Y2 The calculated value with the larger absolute value is kN; A——Cross-sectional area of ​​the connection device at the deck or bottom, cm 2 ; [σ] —— allowable normal stress; The composite stress σc of the connection device between the side pontoon and the main pontoon should meet the following calculation requirements: ≥ ； Where: [σc] —— allowable composite stress; The strength check of the connection device between the rear pontoon and the main pontoon is calculated by referring to the above formula.

4. The combined cutter suction dredger water-borne process according to claim 1 is characterized in that: The deflection of the main pontoon and the side pontoon modules during hoisting is calculated as follows: Each pontoon is simplified as a box body, without considering the internal reinforcement, and the stern deflection fstern is calculated as follows: W = I / e; M=G1*L1; σ=M / W<[σ]; fstern = G1*L13 / 3EI; Where: I——moment of inertia, mm 4 ; e——the distance from the center of gravity to the bottom plate, mm; W——bending section coefficient, mm 3 ; M ——bending moment, N / mm²; [σ]——allowable normal stress, MPa; f——deflection, mm; The bow deflection fb is calculated as follows: M=G2*L2; σ=M / W<[σ] fb = G2*L23 / 3EI.

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