Navigation building approach channel entrance width determination method

Abstract

The invention discloses a navigation building approach channel entrance width determination method, and particularly relates to the technical field of approach channel design. According to a ship lock approach channel, an entrance area, connection section arrangement, representative ship navigation capability and on-way navigation water flow conditions, dynamic change characteristics of ship navigation are considered; and establishing a ship transverse drift accumulation calculation formula in the process of driving the ship into the approach channel, accurately predicting the drift condition of the ship under the action of water flow, further determining the width of an approach channel entrance, and ensuring that the ship can safely and smoothly drive into the approach channel.

Description

Technical Field

[0001] This invention relates to the field of navigation channel design technology, specifically to a method for determining the width of the entrance gate of a navigation structure. Background Technology

[0002] Navigation structures are crucial control engineering projects on inland waterways, essential engineering facilities for vessels to overcome concentrated water level differences when navigating key waterway projects. They mainly include two types: locks and ship lifts. Navigation structures are generally constructed and operated in conjunction with other structures in water conservancy, hydropower, and water transport hubs. Therefore, the operation of navigation structures is affected by the operation and scheduling of other hub structures, such as flood discharge from spillways and power generation by hydropower stations. Flood discharge and power generation by the hub create significant water flow velocities in the upstream and downstream waterways, generating oblique flows and backflows at the entrance areas of the navigation channels upstream and downstream of the navigation structures. Often, excessive lateral flow velocities can affect the safe and smooth entry and exit of vessels through the navigation channels.

[0003] Another scenario involves navigation structures located on lateral channels intersecting the main channel. The angle between the approach channel and the main channel is typically large, and the entry and exit of vessels are significantly affected by the main channel's flow velocity, again posing a challenge to the safe and smooth passage of vessels. There are clear regulations regarding the flow velocity at the entrance area of ​​navigation structures' approach channels. For Class I to VI navigation structures, the longitudinal flow velocity at the entrance area should not exceed 2 m / s, the transverse flow velocity should not exceed 0.3 m / s, and the backflow velocity should not exceed 0.4 m / s. However, the transverse flow velocity is often difficult to meet these requirements, significantly impacting navigation safety. To reduce the transverse flow velocity and meet the regulations, a series of engineering measures are often required, such as extending long dikes, adding dike piers, adjusting the centerline of the approach channel, and local dredging. On the one hand, these engineering measures are costly and have limited effect on improving the transverse flow. On the other hand, there are situations where the transverse flow cannot meet the regulations regardless of the engineering measures used, such as when the centerline of the approach channel is approximately perpendicular to the main channel. In this situation, the only way to ensure that ships can still enter the pilotage channel smoothly despite the cross current is to increase the width of the pilotage gate.

[0004] Currently, the "General Design Code for Ship Locks" specifies the width of approach channels, providing calculation formulas for single-line locks, double-line locks, and symmetrical and asymmetrical approach channels. These formulas are mainly related to parameters such as the width of passing vessels, the width of waiting vessels, and the safe distance between passing vessels and the shore and waiting vessels. It also stipulates that the width of the approach channel entrance should not be less than 1.5 times the width of the approach channel. While considering the potential influence of crosscurrents on vessels, this fixed multiple is not correlated with water flow conditions and vessel navigation, making it difficult to design a scientifically sound approach channel entrance width. Furthermore, the "Design Code for Waterway Engineering" considers the width of the vessel's track zone when specifying channel width, taking into account the influence of the vessel's drift angle in the track zone width calculation. For Class I to V waterways, a drift angle of 3° is acceptable. However, this drift angle value may not be appropriate, and it does not consider the cumulative effect of drift over the entire navigation process. In summary, given the different navigation conditions at different approach gate areas, existing technologies make it difficult to scientifically and rationally determine the width of the approach gate. Therefore, it is urgent to propose a method for determining the width of the approach gate to provide important support for the design of navigation structures' approach channels. Summary of the Invention

[0005] To address this, the present invention provides a method for determining the width of the approach channel entrance of a navigation structure. Based on the layout of the lock approach channel, entrance area, and connecting section, as well as the navigation capacity of representative vessels and the navigable water flow conditions along the route, and considering the dynamic changes in vessel navigation, a formula for calculating the cumulative lateral drift of a vessel during its entry into the approach channel is established. This method accurately predicts the drift of the vessel under the influence of water flow, thereby determining the width of the approach channel entrance and ensuring that vessels can safely and smoothly enter the approach channel.

[0006] The specific technical solution is as follows: A method for determining the width of the approach gate of a navigation structure, including the following steps:

[0007] (1) Based on the layout of the lock approach channel gate area and connecting section, as well as the channel flow velocity distribution, the distance L from the connecting section to the approach channel gate centerline is divided into n small segments, denoted as Ln. i When i = 1, 2, ..., n, and the flow velocity and the direction of the channel centerline change significantly, the segments should be densified.

[0008] (2) Starting from the connecting segment, the navigation time of the first i-1 segments is calculated step by step as t0, and the cumulative lateral drift is S. H0 The time t for the ship to sail in the i-th segment i And lateral drift S Hi Calculate according to formulas (1) and (2):

[0009]

[0010] Among them, v wThe flow velocity along the centerline of the pilot channel;

[0011] S Hi =v w sinθ(t0)t i (2);

[0012] (3) According to equations (1) and (2), the sailing time of the first i-th segment is t0+t i The cumulative lateral drift is S H0 +S Hi , as t0 and S in the next calculation H0 Repeat the previous calculation until i = n, and obtain S. H0 This refers to the lateral drift that occurs when a ship enters the pilotage channel;

[0013] (4) Finally, the width of the pilotway gate is calculated according to formula (3):

[0014] B0 = 2(S) H0 +0.5b s +△b)(3).

[0015] Preferably, in step (1), the ship's still water speed v is obtained based on the power configuration and navigation and maneuvering performance test results of a representative ship designed for the lock. s Based on prototype observations or numerical calculations, the velocity distribution at the entrance area and connecting sections of the lock approach channel is obtained, along with the velocity v along the centerline of the approach channel. w The angle between the flow direction and the tangent of the pilot channel centerline is θ. The ship is affected by the cross current from the connecting section between the main channel and the entrance area until it enters the pilot channel. The distance L between the connecting section and the entrance of the pilot channel is as follows: The relationship between the ship's speed, current speed, heading, flow direction and time from the connecting section to the entrance of the pilot channel under the action of the water flow is as shown in equation (4):

[0016]

[0017] In the formula, only the time t is unknown, which means the time t0 required for the ship to enter the pilotage channel is obtained.

[0018] Preferably, after determining the total travel time t0 of the vessel, the lateral drift S of the vessel perpendicular to the centerline of the pilotway during the process of entering the pilotway is calculated and determined according to formula (5). H0 :

[0019]

[0020] Preferably, when determining the total lateral drift S of the vessel entering the pilotway... H0Afterwards, due to the safe distance between the ship and the shore or the navigation wall, the width B0 of the pilotway entrance is calculated according to formula (6):

[0021] B0 = 2(S) H0 +0.5b s +△b) (6);

[0022] In the formula, △b is the safe distance from the vessel to the shore or navigation wall, and its value should not be less than 0.5b. s b s The width of a representative ship.

[0023] Compared with the prior art, this invention takes into account comprehensive factors such as ship navigation, water flow conditions, and the layout of the approach channel entrance area and connecting sections. It provides a formula and steps for accurately predicting the lateral drift distance of ships and proposes a reliable method for determining the width of the entrance area. Attached Figure Description

[0024] Figure 1 A schematic diagram illustrating the process of a ship entering a pilotway and the calculation parameters for the width of the entrance, provided by this invention.

[0025] Figure 2 This is a schematic diagram illustrating the segmented calculation process of a ship entering the pilotway, provided by the present invention. Detailed Implementation

[0026] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Example: A 1000-ton lock is being constructed on the bank of a river. A representative vessel is designed with dimensions of 60m × 10.8m × 2.7m (length × width × draft), a main engine power of 400kW, and a maximum still-water speed of 5m / s. The lock's approach channel is nearly perpendicular to the river channel, with a maximum current velocity of 2m / s. As the vessel enters the approach channel from the main channel, it needs to navigate through lateral currents, resulting in lateral drift. Because the angle between the approach channel centerline and the current direction is large, the lateral velocity acting on the vessel is high, failing to meet the required flow velocity at the entrance and connecting sections. Therefore, a reasonable approach channel entrance width needs to be designed to ensure smooth vessel entry. The distance from the approach channel connecting section to the entrance is 400m, consisting mainly of a 220m straight section and a 180m tangent circular arc. The angle between the current direction and the straight section is 10°.

[0028] The method for determining the width of the approach gate of a navigation structure according to the present invention comprises the following calculation steps:

[0029] (1) Based on the layout of the lock approach channel gate area and connecting section, as well as the channel velocity distribution, the distance L0 from the connecting section to the approach channel gate centerline is divided into 10 small segments, denoted as L. i (i = 1, 2, ..., 10), the straight segment is treated as a small segment, while the flow velocity and the direction of the channel centerline change significantly in the arc segment, so the segmentation should be densified and it is divided into 9 arc segments for calculation;

[0030] (2) Starting from the connecting section, calculate the ship's sailing time and lateral drift for each segment step by step. If the sailing time of the first i-1 segments is t0 and the cumulative lateral drift is S, then... H0 The time t for the ship to sail in the i-th segment i And lateral drift S Hi Calculate using the following formula:

[0031]

[0032] Among them, v w The flow velocity along the centerline of the pilot channel;

[0033] S Hi =v w sinθ(t0)t i

[0034] (3) Then the sailing time of the first i-th segment is t0+t i The cumulative lateral drift is S H0 +S Hi , as t0 and S in the next calculation H0 Repeat the previous calculation until i = n, and finally obtain S. H0 This refers to the lateral drift that occurs when a ship enters the pilotway.

[0035] The calculation process of steps (1) to (3) is listed in the table below. The final calculated S H0 It is 87.69m.

[0036]

[0037] (4) Finally, the width of the pilotage gate is calculated using the following formula:

[0038] B0 = 2(S) H0 +0.5b s +△b);

[0039] Among them, b s The length is 10.8m, and Δb is taken as 0.5b.s Therefore, B0 = 196.98m. The final width of the pilotway gate should not be less than 196.98m. In this embodiment, the final gate width is 200m.

[0040] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for determining the width of the entrance gate of a navigation structure, characterized in that: Includes the following steps: (1) Based on the layout of the lock approach channel gate area and connecting section, as well as the channel flow velocity distribution, the distance L from the connecting section to the approach channel gate centerline is divided into n small segments, denoted as Ln. i , i = 1, 2, ..., n; (2) Starting from the connecting segment, the navigation time of the first i-1 segments is calculated step by step as t0, and the cumulative lateral drift is S. H0 The time t for the ship to sail in the i-th segment i And lateral drift S Hi Calculate according to formulas (1) and (2): Among them, v w The velocity along the centerline of the navigation channel; S Hi =v w sinθ(t0)t i (2); (3) According to equations (1) and (2), the sailing time of the first i-th segment is t0+t i The cumulative lateral drift is S H0 +S Hi , as t0 and S in the next calculation H0 Repeat the previous calculation until i = n, and obtain S. H0 This refers to the lateral drift that occurs when a ship enters the pilotage channel; (4) Finally, the width of the pilotway gate is calculated according to formula (3): B0=2(S H0 +0.5b s +△b) (3)。 2. The method for determining the width of the approach gate of a navigation structure according to claim 1, characterized in that: In step (1), based on the power configuration and navigation and maneuvering performance test results of representative ships designed for the lock, the ship's still water speed v is obtained. s Based on prototype observations or numerical calculations, the velocity distribution at the entrance area and connecting sections of the lock approach channel is obtained, along with the velocity v along the centerline of the approach channel. w Given the direction of flow, the angle between the direction of flow and the tangent of the centerline of the pilot channel is θ, and the distance L between the connecting section and the entrance of the pilot channel, the relationship between the distance traveled by the ship from the connecting section to the entrance of the pilot channel under the action of water flow and the speed, current speed, heading, direction of flow, and time is as shown in equation (4): In the formula, only the time t is unknown, which means the time t0 required for the ship to enter the pilotage channel is obtained.

3. The method for determining the width of the approach gate of a navigation structure according to claim 1, characterized in that: After determining the total travel time t0 of the vessel, the lateral drift S of the vessel perpendicular to the centerline of the pilotway during the process of entering the pilotway is calculated and determined according to formula (5). H0 :

4. The method for determining the width of the approach gate of a navigation structure according to claim 1, characterized in that: Determine the total lateral drift S of the vessel entering the pilotage channel. H0 Afterwards, due to the safe distance between the ship and the shore or the navigation wall, the width B0 of the pilotway entrance is calculated according to formula (6): B0=2(S H0 +0.5b s +△b) (6); In the formula, △b is the safe distance from the vessel to the shore or navigation wall, and its value should not be less than 0.5b. s b s The width of a representative ship.

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