A method of trenching with a cutter suction dredger

Abstract

The application provides a kind of arc-shaped trenching cutter suction dredger excavation method, its characterized in that specific steps are as follows: step one obtains cutter suction dredger hull dimension, left and right edge lines and the excavation data of axis, and establishes mathematical model according to this, step two obtains the relative footage difference of left and right edge lines in single trolley travel of cutter suction dredger, and uses this data as discriminant index, step three calculates the coordinates of channel axis tangent point and tangent line equation, step four obtains the construction auxiliary guide map of arc-shaped trenching of cutter suction dredger and keeps cutter suction dredger steel pile always located on tangent line to carry out transverse moving excavation;The application can reduce ship moving frequency under the condition of ensuring that the excavation volume of left and right half of trench is similar, ensure that the cutting amount of left and right sides of arc excavation is similar, the excavation productivity is stable and efficient, improve the production capacity of cutter suction dredger, reduce the plane construction error, and the method can be applied to cutter suction dredger excavation of various arc-shaped trenches.

Description

Technical Field

[0001] This invention relates to the field of dredging engineering technology, and more particularly to a method for excavating arc-shaped trenches using a cutter suction dredger. Background Technology

[0002] Cutter suction dredgers are one of the most common types of dredgers used in dredging projects. They are generally equipped with a steel pile trolley system, a lateral movement system, and an excavation system. The bottom of the steel pile is fixed in the seabed soil, and the upper part of the steel pile is connected to the trolley. The hull moves forward or backward under the push of the trolley's hydraulic cylinder. The cutter head of the cutter suction dredger moves in an arc around the steel pile under the action of the lateral movement system to achieve continuous excavation.

[0003] Cutter suction dredgers typically excavate straight, regular areas such as channels, harbor basins, and berths. In this case, steel piles need to be set on the axis of the excavation trench, and the excavation area of ​​the left and right halves of the trench is the same.

[0004] However, when the cutter suction dredger encounters arc-shaped areas such as the turning circle of a ship, and the excavation areas of the left and right halves of the trench are different, if the steel piles of the cutter suction dredger fall on the axis of the trench, it will cause uneven feed and excavation volume of the cutter suction dredger from left to right. The feed and excavation volume on the inner arc side will be relatively insufficient, which will affect the excavation productivity. Moreover, this impact will continue to increase as the cutter suction dredger advances, making it increasingly difficult to control the construction parameters and having a greater and greater impact on productivity and excavation quality. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides a method for excavating arc-shaped trenches by a cutter suction dredger, which can reduce the number of times the vessel needs to be moved while ensuring that the excavation volume of the left and right halves of the trench is similar, ensure that the cutting volume of the left and right sides of the excavation arc is similar, maintain stable and efficient excavation productivity, improve the production capacity of the cutter suction dredger, reduce planar construction errors, and is applicable to the excavation of various arc-shaped trenches by cutter suction dredgers.

[0006] This invention provides a method for excavating arc-shaped trenches using a cutter suction dredger, characterized by the following specific steps:

[0007] Step 1: Obtain the excavation data of the cutter suction dredger's hull dimensions, left and right sides of the trench, and axis, and use this data to establish the boundary conditions of the mathematical model;

[0008] Step 2: Obtain the relative advance difference between the left and right sides of the cutter suction dredger within the stroke of a single trolley, and use this data as a criterion;

[0009] Step 3: Calculate the coordinates of the tangent point and the equation of the tangent line to the channel axis;

[0010] Step 4: Obtain the construction auxiliary guide map for the cutter suction dredger's arc-shaped trench and keep the cutter suction dredger's steel piles always on the tangent line during lateral excavation.

[0011] The specific calculation method for the boundary conditions of the mathematical model in step one is as follows:

[0012] When the travel of the cutter suction dredger's steel pile trolley is 0, let the horizontal distance from the cutter head to the steel pile be L, and the maximum travel of the trolley be ΔL. When the travel of the steel pile trolley is at its maximum, the horizontal distance from the cutter head to the steel pile is...

[0013] L+ΔL;

[0014] There are m discrete points along the channel axis, and the discrete point Q is... i coordinates (x) i y i ), where i∈(1,m);

[0015] At discrete point Q i Every s data points, one point is selected to form an n×2 discrete point matrix M, where the coordinates of each point are M. j coordinates (x) j y j ), where i∈(1,n).

[0016] The specific calculation method for obtaining the hull dimensions, left and right sides of the excavation trench, and axis of the cutter suction dredger in step one is as follows:

[0017] Take three consecutive discrete points M j-1 M j M j+1 The area of ​​the triangle formed is S j The side length is a j b i c i ,but:

[0018]

[0019]

[0020]

[0021]

[0022] Point M j The radius of curvature of the channel axis is:

[0023]

[0024]

[0025] If the width of the trench is B, then the radius of curvature of the inner edge is R. i -B / 2, the radius of curvature of the outer edge is R. i +B / 2;

[0026] |O3M j |=Rj

[0027] |O3D|=O3F=R j -B / 2

[0028] |O3E|=O3G=R j -B / 2.

[0029] The specific calculation method for obtaining the relative advance difference between the left and right sides of the cutter suction dredger within a single trolley stroke in step two is as follows:

[0030] Passing M j Draw a tangent I-I along the channel axis, so that the cutter suction dredger's steel pile is positioned at the tangent.

[0031] At point O1, the cutter falls on point M. j Point, then |O1M j |=L, the cutter head excavation trajectory is an arc The cutter suction dredger moves forward along tangent line I-I, with the steel pile always situated on tangent line I-I. Let the location of the steel pile be O2, and let |O1O2| = x. When the steel pile trolley travels at 0, the cutter's excavation trajectory is an arc. Then |O2D|=|O2E|=L, and when the stroke of the steel pile trolley is ΔL, the cutter head excavation trajectory is an arc. Then |O2F|=|O2G|=L+ΔL;

[0032] According to geometric relationships:

[0033] O2M j |=O1M j -O1O2=Lx

[0034]

[0035] Within ΔO2EO3, |O2E|=L, |O3E|=R j -B / 2, by the Law of Cosines, we get:

[0036]

[0037]

[0038] Similarly, within ΔO2EO3:

[0039]

[0040]

[0041] so:

[0042] ∠EO3G=∠O2O3G-∠O2O3E

[0043] arc length

[0044] Similarly:

[0045]

[0046]

[0047]

[0048]

[0049] ∠DO3F=∠O2O3F-∠O2O3D

[0050] arc length

[0051] Let the arc length be With arc length The difference is Δl:

[0052]

[0053] The relative advance difference between the left and right edges of a single cutter suction dredger within its single carriage stroke is ε. A critical value [ε] is set:

[0054]

[0055] The specific calculation method for step three is as follows:

[0056] The maximum value of x can be obtained by solving the above formula. max Then we have:

[0057]

[0058] |O2H|=L+ΔL

[0059] |O3H|=R j

[0060]

[0061]

[0062]

[0063]

[0064] but:

[0065]

[0066] |M j H|=|M j O3| 2 +|O3H| 2 -2|M jO3||O3H|cos∠M j O3H

[0067] |M j H|=2R j 2 (1-cos∠M j O3H)

[0068] Verification of M j For each subsequent point, let u > j, and point M... u coordinates (x) u y u Point M u+1 coordinates (x) u+1 y u+1 Point M u-1 coordinates (x) u-1 y u-1 ),but:

[0069]

[0070]

[0071] When |M j M u |>|M j H|, and |M j M u+1 |>|M j H|, then define M u The next tangent point to the channel axis, with coordinates (x... u y u The slope of the tangent is:

[0072]

[0073] The equation of the tangent is:

[0074]

[0075] The specific method for step four is as follows:

[0076] Continue to calculate the next tangent point and tangent line according to the specific calculation methods described in steps one to three, and continuously iterate to obtain each tangent point and tangent line of the entire channel axis. On this basis, draw the construction auxiliary guide diagram for the cutter suction dredger's arc-shaped trenching.

[0077] When a cutter suction dredger is excavating, it first places the steel pile on the first tangent line. The cutter head is aligned with the tangent point to begin arc-shaped excavation. The hull moves forward along the first tangent line. When the cutter head touches the second tangent point, it is lowered at the second tangent point and contacts the seabed. The steel pile is then lifted. With the help of the propeller or auxiliary vessels, the hull of the cutter suction dredger rotates around the cutter head. When the steel pile moves to the second tangent line, it is lowered again, and the excavation continues along the second tangent line. When the cutter head touches the third tangent point, the operation is the same, and so on, until the arc-shaped trench excavation is completed.

[0078] The beneficial effects of this invention are as follows: This invention provides a method for excavating arc-shaped trenches using a cutter suction dredger, which ensures that the cutting depth on both sides of the cutter suction dredger's arc is similar, resulting in stable and efficient excavation productivity, and avoids a decrease in excavation productivity due to insufficient soil supply on the inner arc side; at the same time, the critical value of the relative advance difference between the left and right sides can be adjusted according to requirements, controlling the number and spacing of tangent points, minimizing the number of vessel movements while ensuring that the excavation volume of the left and right halves of the trench is similar, thereby improving excavation efficiency and saving time; in addition, the angle between the cutter suction dredger's arc and the channel axis and side lines can be increased, optimizing the cutter suction dredger's excavation posture, reducing planar construction errors, and improving excavation accuracy. Attached Figure Description

[0079] Figure 1 This is a schematic diagram of the radius of curvature of the arc-shaped trench of the present invention;

[0080] Figure 2 This is a schematic diagram illustrating the calculation of the relative advance difference between the left and right sides of the arc-shaped trench in this invention;

[0081] Figure 3 This is a schematic diagram illustrating the calculation of the relative advance difference between the left and right sides of the arc-shaped trench in this invention;

[0082] Figure 4 This is a schematic diagram illustrating the calculation of the coordinates of the tangent point of the arc-shaped trench axis in this invention;

[0083] Figure 5 This is a schematic diagram illustrating the calculation of the tangent equation for the arc-shaped trench axis of the present invention;

[0084] Figure 6 This is a construction auxiliary guide diagram for the present invention.

[0085] Reference numerals in the attached drawings: 1. Inner edge of the trench; 2. Outer edge of the trench; 3. Trench axis; 4. Tangent point of the axis; 5. Tangent line of the axis; 6. Cutter suction dredger. Detailed Implementation

[0086] Example 1

[0087] The steps for calculating the coordinates of the tangent point and the equation of the tangent line of the waterway axis based on the mathematical model are as follows:

[0088] Step 1: Establish the boundary conditions of the mathematical model. The calculation method is as follows:

[0089] When the travel of the cutter suction dredger's steel pile trolley is 0, let the horizontal distance from the cutter head to the steel pile be L, then the maximum travel of the trolley is ΔL. When the travel of the steel pile trolley is at its maximum, the horizontal distance from the cutter head to the steel pile is L+ΔL.

[0090] If there are m discrete points along the waterway axis, and the discrete point Q... i coordinates (x) i y i ), where i∈(1,m).

[0091] At discrete point Q i Every s data points, one point is selected to form an n×2 discrete point matrix M, where the coordinates of each point are M. j coordinates (x) j y j ), where i∈(1,n).

[0092] Step 2: Calculate the radius of curvature of the arc-shaped trench.

[0093] like Figure 2 As shown, three consecutive discrete points M j-1 M j M j+1 The area of ​​the triangle formed is S j The side length is a j b i c i ,but:

[0094]

[0095]

[0096]

[0097]

[0098] Point M j The radius of curvature of the channel axis is:

[0099]

[0100]

[0101] If the trench width is B, then the radius of curvature of the inner edge is R. i -B / 2, the radius of curvature of the outer edge is R. i +B / 2.

[0102] |O3M j |=R j

[0103] |O3D|=O3F=Rj +B / 2

[0104] |O3E|=O3G=R j -B / 2

[0105] Step 3: Calculate the relative advance difference between the left and right edges.

[0106] like Figure 3 As shown, through M j Draw a tangent II along the channel axis, positioning the cutter suction dredger's steel pile at tangent point O1, with the cutter head resting on point M. j Point, then |O1M j |=L, the cutter head excavation trajectory is an arc The cutter suction dredger moves forward along tangent II, with the steel pile always resting on tangent II. Let the location of the steel pile be O2, and let |O1O2|=x. When the steel pile trolley travels 0, the cutter's excavation trajectory is an arc. Then |O2D|=|O2E|=L, and when the stroke of the steel pile trolley is ΔL, the cutter head excavation trajectory is an arc. Then |O2F|=|O2G|=L+ΔL.

[0107] According to geometric relationships:

[0108] O2M j |=O1M j -O1O2=Lx

[0109]

[0110] Within ΔO2EO3, |O2E|=L, |O3E|=R j -B / 2, by the Law of Cosines, we get:

[0111]

[0112]

[0113] Similarly, within ΔO2EO3:

[0114]

[0115]

[0116] so:

[0117] ∠EO3G=∠O2O3G-∠O2O3E

[0118] arc length

[0119] Similarly:

[0120]

[0121]

[0122]

[0123]

[0124] ∠DO3F=∠O2O3F-∠O2O3D

[0125] arc length

[0126] Let the arc length be With arc length The difference is Δl:

[0127]

[0128] The relative advance difference between the left and right edges of a single cutter suction dredger within its single carriage stroke is ε. A critical value [ε] is set:

[0129]

[0130] Step 4: Calculate the coordinates of the point of tangency on the axis and the equation of the tangent line.

[0131] like Figure 4 As shown,

[0132]

[0133] |O2H|=L+ΔL

[0134] |O3H|=R j

[0135]

[0136]

[0137]

[0138]

[0139] but:

[0140]

[0141] |M j H|=|M j O3| 2 +|O3H| 2 -2|M j O3||O3H|cos∠M j O3H

[0142] |Mj H|=2R j 2 (1-cos∠M j O3H)

[0143] Verification of M j For each subsequent point, let u > j, and point M... u coordinates (x) u y u Point M u+1 coordinates (x) u+1 y u+1 Point M u-1 coordinates (x) u-1 y u-1 ),but:

[0144]

[0145]

[0146] When |M j M u |≤|M j H|, and |M j M u+1 |≤|M j H|, then define M u The next tangent point to the channel axis, with coordinates (x... u y u The slope of the tangent is:

[0147]

[0148] like Figure 5 As shown, the equation of the tangent is:

[0149]

[0150] Step 5: Conduct on-site implementation according to the construction auxiliary guide map.

[0151] Following the above procedure, continue calculating the next tangent point and tangent line, and continuously iterate to obtain all tangent points and tangent lines along the entire channel axis. Based on this, draw the construction auxiliary guidance diagram for the cutter suction dredger's arc-shaped trenching, such as... Figure 6 As shown.

[0152] When a cutter suction dredger is excavating, it first places the steel pile on the first tangent line. The cutter head is aligned with the tangent point to begin arc-shaped excavation. The hull moves forward along the first tangent line. When the cutter head touches the second tangent point, it is lowered at the second tangent point and contacts the seabed. The steel pile is then lifted. With the help of the propeller or auxiliary vessels, the hull of the cutter suction dredger rotates around the cutter head. When the steel pile moves to the second tangent line, it is lowered again, and the excavation continues along the second tangent line. When the cutter head touches the third tangent point, the operation is the same, and so on, until the arc-shaped trench excavation is completed.

[0153] Example 2

[0154] According to the calculation method in Example 1, the specific construction data are as follows:

[0155] A dredging project involves excavating an arc-shaped trench. The trench is 120m wide, with a bending radius of 310m, an angle of 180 degrees, and a length of 937m. When the cutter suction dredger's steel pile trolley travels to zero, the horizontal distance between the cutter head and the steel pile is 116m. The maximum travel of the trolley is 6m. When the steel pile trolley travels to its maximum, the horizontal distance between the cutter head and the steel pile is 122m.

[0156] Initially, the cutter suction dredger's steel piles were excavated along the channel axis. During one trolley stroke, the dredger advanced 6 meters along the axis, with an arc length of 7.68 meters at the outer edge and 6.34 meters at the inner edge, a difference of 1.34 meters. This significant difference in advancement between the left and right edges resulted in insufficient soil supply on the inner arc side of the excavation, reducing excavation productivity. If the cutter suction dredger's steel piles were placed outside the channel axis, determining the pile location would be difficult.

[0157] Using this method, a total of 1200 discrete points along the channel axis are uniformly spaced. A discrete point matrix M is formed by selecting one point every 10 data points. The critical value for the relative advance difference between the left and right sides is set to 15%. The calculation results are: 16 tangent points, 16 tangent lines, and an arc length of 62.5m between adjacent tangent points, forming a construction auxiliary guidance diagram. When the cutter suction dredger is excavating for one trolley stroke, the maximum difference in the advance arc length between the left and right sides is 0.9m (at this time, the advance arc lengths at the inner and outer sides are 6.5m and 7.4m respectively). During excavation, the steel piles are positioned on the tangent lines. When the vessel advances to the point where the cutter head contacts the next tangent point, the steel piles are moved and positioned on the next tangent line to continue excavation. Using this method, the overall productivity is increased by 4% compared to the method of excavating with the steel piles positioned on the channel axis.

[0158] Example 3

[0159] In another dredging project, when excavating an arc-shaped trench, the trench width was 100m, the bending radius of the axis was 410m, the angle of the arc-shaped trench was 180 degrees, and the length of the axis was 1280m. When the travel of the cutter suction dredger's steel pile trolley was 0, the horizontal distance between the cutter head and the steel pile was 95m. The maximum travel of the trolley was 6m. When the travel of the steel pile trolley was at its maximum, the horizontal distance between the cutter head and the steel pile was 101m.

[0160] Initially, the cutter suction dredger's steel piles were excavated on the channel axis. After one trolley stroke, the cutter suction dredger advanced 6m along the axis. The arc length of advancement at the outer edge was 7.76m, and the arc length of advancement at the inner edge was 6.21m, a difference of 1.55m. The difference in advancement on both sides was even greater.

[0161] Using this method, a total of 1400 discrete points were obtained along the channel axis. One point was selected every 20 data points to form a discrete point matrix M. The critical value for the relative advance difference between the left and right sides was set to 12%. The calculation results are as follows: 21 tangent points, 21 tangent lines, and an arc length of 58.4m between adjacent tangent points. When the cutter suction dredger is excavating for one trolley stroke, the maximum difference in the advance arc length between the left and right sides is 0.78m. Using this method, the overall productivity is 3.6% higher than the method of excavating with steel piles placed on the channel axis.

[0162] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. The various components mentioned in this invention are common technologies in the existing field. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A method for excavating arc-shaped trenches using a cutter suction dredger, characterized in that... The specific steps are as follows: Step 1: Obtain the excavation data of the cutter suction dredger's hull dimensions, left and right sides of the trench, and axis, and use this data to establish the boundary conditions of the mathematical model; Step Two: Obtain the relative advance difference between the left and right sides of the cutter suction dredger within a single trolley stroke, and use this data as a criterion. The specific calculation method is as follows: Draw a tangent along the channel axis to position the cutter suction dredger's steel piles at the tangent. The auger fell Point, then The cutting tool's excavation trajectory is an arc. Let the location of the steel pile be... ,set up When the steel pile trolley travels to 0, the cutter excavation trajectory is an arc. ,but The stroke of the steel pile trolley is At that time, the cutter head's excavation trajectory is an arc. ,but ; According to geometric relationships: ； ； , By the Law of Cosines: ； ； Similarly, : ； ； ： ； arc length ; Similarly: ； ； ； ； ； arc length ; Let the arc length be With arc length The difference is : ； The relative advance difference between the left and right sides of the cutter suction dredger within the stroke of a single trolley is Set the threshold value : ； Step 3: Calculate the coordinates of the tangent point and the equation of the tangent line along the channel axis. The specific calculation method is as follows: ; ； ； ； ； ； ； but: ； ； ； Verification For each subsequent point, set point ,point ,point ,but: ； ； When satisfied ,and Then define The next tangent point on the channel axis, with coordinates as follows: The slope of the tangent is: ； The equation of the tangent is: 。 2. The method for excavating an arc-shaped trench using a cutter suction dredger according to claim 1, characterized in that... The specific calculation method for the boundary conditions of the mathematical model in step one is as follows: When the travel of the cutter suction dredger's steel pile trolley is 0, the horizontal distance from the cutter head to the steel pile is set. The maximum travel of the trolley is When the steel pile trolley has its maximum travel, the horizontal distance between the cutterhead and the steel pile is: ; There are m discrete points along the channel axis. coordinate ,in ; At discrete points Select one point every s data points to form a... The discrete point matrix M, with coordinates of each point as follows: ,in .

3. The method for excavating an arc-shaped trench using a cutter suction dredger according to claim 1, characterized in that... The specific calculation method for obtaining the hull dimensions, left and right sides of the excavation trench, and axis of the cutter suction dredger in step one is as follows: Take three consecutive discrete points , The area of ​​the triangle formed is The side length is , , ,but: ； ； ； ； point The radius of curvature of the channel axis is: ； ； If the width of the trench is B, then the radius of curvature of the inner edge is... The radius of curvature of the outer edge is ; ； ； 。 4. The method for excavating an arc-shaped trench using a cutter suction dredger according to claim 1, characterized in that... The process also includes step four, which involves obtaining a construction auxiliary guide diagram for the cutter suction dredger's arc-shaped trench and ensuring that the cutter suction dredger's steel piles remain on the tangent line during lateral excavation. The specific method for step four is as follows: Continue to calculate the next tangent point and the next tangent line according to the specific calculation methods described in steps one to three, and continuously iterate to obtain each tangent point and each tangent line of the entire channel axis. On this basis, draw the construction auxiliary guide diagram for the cutter suction dredger's arc-shaped trenching. When a cutter suction dredger is excavating, it first places the steel pile on the first tangent line. The cutter head is aligned with the tangent point to begin arc-shaped excavation. The hull moves forward along the first tangent line. When the cutter head touches the second tangent point, it is lowered at the second tangent point and contacts the seabed. The steel pile is then lifted. With the help of the propeller or auxiliary vessels, the hull of the cutter suction dredger rotates around the cutter head. When the steel pile moves to the second tangent line, it is lowered again, and the excavation continues along the second tangent line. When the cutter head touches the third tangent point, the operation is the same, and so on, until the arc-shaped trench excavation is completed.

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