A weir dam system and method for automatically self-adapting hydraulic sand discharge and scouring

Abstract

The application discloses a weir dam system and method for automatically discharging and scouring silt in an adaptive hydraulic manner, which comprises a water storage area, a sand collecting module and a diversion weir module arranged in sequence from a land end to a sea end, wherein the diversion weir module comprises a weir top surface, a first streamlined diversion slope surface facing the land end, and a second streamlined diversion slope surface facing the sea end, the weir top surface is provided with a gate for controlling the on-off of water flow in a channel, and the top surface elevation of the diversion weir module is lower than the bottom surface elevation of the water storage area; the sand collecting module comprises a sand collecting bottom surface and a streamlined sand falling slope surface, one side of the sand collecting bottom surface is connected to the water storage area in a smooth transition manner through the streamlined sand falling slope surface, the other side is connected to the first streamlined diversion slope surface in a smooth transition manner, and the bottom surface elevation of the sand collecting module is lower than the bottom surface elevation of the first streamlined diversion slope surface. The application realizes the integration of active silt prevention and real-time silt removal, and can solve the problem of repeated silt accumulation in a channel under the action of bidirectional water flow caused by tides.

Description

Technical Field

[0001] This invention relates to the field of water conservancy engineering technology, and in particular to an adaptive hydraulic automatic sand and silt removal weir system and method. Background Technology

[0002] Discharge channels and coastal tidal gates are subject to the bidirectional tidal flow and alternating hydrodynamic forces from upstream and downstream, resulting in complex sediment transport patterns and making them frequent areas of siltation. The complex flow patterns and insufficient water diffusion at the nodes of these channels and gates further exacerbate sediment retention and accumulation. During high tide, high-sediment-laden currents from the open sea flow upstream along the channels, causing a sharp drop in flow velocity and continuous settling of fine-grained sediment and bottom mud. During low tide, insufficient kinetic energy within the channels prevents the complete removal of accumulated sediment, leading to persistent and stubborn siltation problems due to the cyclical nature of the tides.

[0003] Long-term siltation can cause a series of negative impacts: First, it compresses the flow cross-section, weakening the flood control and drainage capacity of channels and culverts; second, siltation raises the riverbed, altering the original hydrodynamic conditions and affecting regional water system connectivity; third, long-term accumulation of various pollutants in the sediment causes the water to turn black and smelly, deteriorating water quality and severely damaging the coastal marine ecosystem; fourth, long-term siltation alters the local tidal dynamic balance, exacerbating shoreline erosion and affecting the structural stability and service life of coastal outfalls, dams, dikes, and other water conservancy projects.

[0004] Currently, the mainstream dredging methods in the industry are mechanical dredging and high-pressure water jet flushing: mechanical dredging, such as using excavators and dredgers, is only suitable for open channels and wide waterways; high-pressure water jet flushing is mostly used for closed culverts. Both methods are highly dependent on specialized equipment, and routine dredging is costly; the operation requires on-site personnel, and the safety risks are prominent when operating in confined spaces such as enclosed culverts and dam bottoms, and the operation in dam areas is difficult, often resulting in incomplete dredging.

[0005] Meanwhile, existing inland reservoir water storage and sediment flushing hydraulic dredging technologies are only suitable for inland unidirectional runoff and seasonal water inflow conditions. They rely on manual, phased control of hydraulic structures to achieve intermittent, concentrated dredging, and cannot adapt to the characteristics of bidirectional tidal flow and periodic tidal level changes, nor can they be applied to closed culverts or narrow canals. Both traditional dredging methods and existing hydraulic dredging technologies belong to a passive treatment mode of addressing siltation after it occurs, failing to match the dynamic tidal siltation patterns for proactive prevention. This results in significant repeated siltation problems and makes it difficult to maintain long-term operational effectiveness. Summary of the Invention

[0006] The purpose of this invention is to provide an adaptive hydraulic automatic sand and silt removal weir system and method, which integrates active silt prevention and real-time silt removal, and can fundamentally solve the problem of repeated siltation in channels such as drainage canals, tidal gates, and open and closed culverts affected by bidirectional tidal flow.

[0007] To achieve the above objectives, the technical solution proposed by this invention is as follows: Firstly, an adaptive hydraulic automatic sediment flushing and silt removal weir system is provided, which is installed within a channel, wherein the channel is a land end near the inland area and a near-shore end connecting to the external sea area. The weir system includes a water storage area, a sediment collection module, and a diversion weir module arranged sequentially from the land end to the near-shore end. The diversion weir module includes a weir crest, a first streamlined diversion slope facing the land end, and a second streamlined diversion slope facing the near-shore end. The weir crest is equipped with a gate for controlling the flow of water within the channel. The top elevation of the diversion weir module is lower than the bottom elevation of the water storage area. The sediment collection module includes a sediment collection bottom surface and a streamlined sediment fall slope. One side of the sediment collection bottom surface smoothly transitions to the water storage area via the streamlined sediment fall slope, and the other side smoothly transitions to the first streamlined diversion slope. The bottom elevation of the sediment collection module is lower than the bottom elevation of the first streamlined diversion slope.

[0008] Preferably, the curvature of both the first and second streamlined guide slopes gradually increases from their respective bottom edges to their top edges, reaching a peak curvature within 60% to 70% of their total horizontal projection length, and then gradually decreases and smoothly connects to the weir crest surface; the curvature of the weir crest surface does not exceed 20% of the peak curvature of each of the first and second streamlined guide slopes; the slope of the first and second streamlined guide slopes from their bottom edges to the peak curvature is 1:30 to 1:5.0, the slope from the peak curvature to the top edge is 1:1.5 to 1:2.5, and the slope of the top surface is ≤1:20.

[0009] Preferably, the curvature of the streamlined sand-falling slope gradually increases from the sand-collecting module towards the water-retaining area to a peak curvature, then gradually decreases and smoothly connects to the water-retaining area. The peak curvature of the streamlined sand-falling slope is located within 50% to 65% of the horizontal length from the bottom edge of the sand-collecting module. The slope of the streamlined sand-falling slope from the bottom edge to the peak curvature is 1:2.0 to 1:3.5, and the slope from the peak curvature to the top edge is 1:4.0 to 1:6.0.

[0010] Preferably, the sand collection module is a transverse continuous groove structure with a groove depth of 0.4 to 1.0 m. The maximum sand collection volume of a single tide is V = L × B × H, where: L is the length of the sand collection groove, B is the net width of the sand collection groove, and H is the effective depth of the sand collection groove. At the same time, it satisfies V ≥ 1.2 × S × Qin, where: S is the sand content of the water body, and Qin is the total amount of inflow in a single high tide.

[0011] Preferably, the surfaces of the diversion weir module and the sand collection module are coated with a low-resistance protective coating that is resistant to seawater abrasion.

[0012] Preferably, it also includes a water level monitoring device for monitoring water level changes in the channel and a controller for receiving signals from the water level monitoring device and controlling the opening and closing of the gate.

[0013] Preferably, the channel is one of the following: a sea drainage culvert, a tidal gate dam, an open culvert, and a culvert; at least the sand collection module and the diversion weir module are prefabricated components.

[0014] Secondly, a method for flushing and removing sediment is provided, utilizing the weir system of the present invention, comprising: obtaining the high tide level; when the high tide level rises to a first preset water level, opening the gate to allow the sediment-laden tidal current from the open sea to enter the storage area, with some of the sediment from the tidal current pre-settling in the sediment collection module; the first preset water level is not lower than the top surface elevation of the guide weir module; obtaining the low tide level; when the low tide level falls back to the preset water storage height of the storage area, closing the gate to allow the remaining sediment to settle throughout the area, with some sediment naturally collecting in the sediment collection module; when the low tide level falls back to a second preset water level, opening the gate and adjusting the gate opening, generating a flushing flow through the water level difference to flush the sediment settled in the sediment collection module along the guide weir module; the second preset water level is not higher than the top surface elevation of the guide weir module; obtaining the water level at the sediment collection module; when the water level at the sediment collection module drops to a third preset water level, closing the gate; the third preset water level is not higher than the top surface elevation of the guide weir module.

[0015] Preferably, the gate opening is controlled by either a tidal time-series segmented preset control method or a water level monitoring closed-loop automatic control method. The tidal time-series segmented preset control method involves dividing the sediment flushing process into multiple time-series intervals based on multi-year measured tidal process curves of the target area, with each interval corresponding to a pre-stored fixed gate opening for the average water level difference. The water level monitoring closed-loop automatic control method involves real-time acquisition of the water level inside the storage area and the nearshore tidal level using a water level monitoring device, real-time calculation of the dynamic water level difference ΔH, and control of the gate opening by the controller through an opening control equation to stabilize the sediment flushing velocity within the target range. The opening control equation is: b(ΔH) = In the formula: b(△H) is the effective flow opening of the gate that dynamically changes with the water level difference; μ is the gate orifice flow coefficient, with a value of 0.58 to 0.68; B 渠 denoted as the channel width; g is the gravitational acceleration; ΔH is the real-time water level difference between the water level in the storage area and the tidal level at the nearshore end; Q is the real-time total discharge from the storage area downstream at the current moment.

[0016] Preferably, the method for determining the real-time total flow rate Q released downstream from the water storage area at the current moment is as follows: Instantaneous cross-sectional flow velocity and water depth are collected using channel cross-sectional velocity monitoring devices and water level monitoring devices. The instantaneous discharge rate is then calculated in real time using the cross-sectional integral method. In the formula: v 实 h represents the measured flow velocity at the cross-section within the channel. 内 Real-time water depth of the reservoir area; Alternatively, by pre-setting the maximum water storage volume V of the water storage area. 存 Total duration of a single standard discharge (T) 泄 The estimated average discharge current Q is used as a fixed input value for segmented timing control: .

[0017] Preferably, the second preset water level is not higher than the elevation of the bottom surface of the channel.

[0018] Preferably, the hard limit of the gate opening control is: the minimum effective gate opening is ≥0.15m, and the maximum gate opening does not exceed 70% of the channel net height.

[0019] Preferably, the high tide level and low tide level are obtained through a tide forecast report or a water level monitoring device.

[0020] By adopting the above technical solution, the beneficial effects of the present invention are as follows: (1) This invention adapts to the tidal cycle to achieve closed-loop hydraulic circulation. It adopts the operation mode of "sand collection during high tide, water storage during low tide, and continuous jet flushing of sand by dynamic water level difference". It is different from the traditional technology and the passive treatment mode of "sludge accumulation first and then concentrated dredging" of inland reservoir hydraulic dredging. It realizes the integration of active silt prevention and real-time dredging, and can solve the problem of repeated silt accumulation in channels such as drainage canals, tidal gates, and open and closed culverts affected by the bidirectional tidal flow from the root.

[0021] (2) This invention relies on tidal level differences and natural water flow as power sources, requiring no external energy sources such as electricity or fuel, and no additional water diversion. It consumes zero energy throughout the entire process, unlike the high-energy-consuming modes of mechanical dredging and high-pressure jet dredging. The entire system does not require the configuration of special dredging equipment such as dredgers and high-pressure water guns, nor does it require personnel to be on duty or maintain the equipment regularly. This can significantly reduce the later operation and maintenance costs and the overall project cost. During the system operation, no personnel need to enter closed and high-risk areas such as culverts and sluice gate bottoms, which can avoid the safety risks of working in confined spaces. The system can operate continuously without the need for river flow interruption, and is minimally affected by weather and temporary water condition disturbances, with strong operational stability.

[0022] (3) The present invention designs a bidirectional streamlined guide weir module for the bidirectional tidal flow characteristics, and is equipped with a sand collection module. The water flow in the channel is smooth and free of turbulence. At the same time, it relies on the linkage control of water level difference and gate opening to form a constant strong jet, which can fully stir up and transport the sediment at the bottom of the channel. The single dredging is more thorough and the sediment residue is less, which can solve the pain points of traditional gates, weirs, bottom sand accumulation and dredging blind spots.

[0023] (4) This system can use prefabricated modular components in the factory and be directly assembled on site. It can be directly installed inside existing sluice gates, dams, and culverts without the need for new construction land, large-scale earthwork and civil engineering, or changes to the main structure of the original water conservancy project. The renovation of old culverts is easier and the construction period is shorter. Applicable scenarios are specifically covered for coastal tidal open channels, closed culverts, water conveyance pipelines, tidal rivers, coastal gate stations and other water conservancy facilities. It can be used to support the construction of new tidal culvert projects, as well as for the quality improvement and renovation of old coastal culverts, sluice gates and dams. Its application scope is wide. All structures have been optimized by hydraulic special projects. They do not compress the original flood discharge section or obstruct the normal flow of water, and fully guarantee the original functions of flood control and drainage and regional water system connectivity of culverts.

[0024] (5) The system can maintain the smooth flow of the canal and culvert without siltation for a long time, avoiding problems such as reduced flood discharge capacity and abnormal scouring of the banks caused by sediment accumulation. It can comprehensively protect coastal dams, dikes, outlets and other water conservancy structures, and extend the overall service life of the project. It is conducive to continuously reducing the accumulation of bottom sediment and pollutants, curbing the blackening and odor of water bodies from the source, and effectively improving the water quality and aquatic ecological environment of the coastal area. The entire system mainly relies on natural water conservancy for operation, with lower energy consumption, no external additives, and no secondary pollution. It belongs to ecological dredging technology and meets the current requirements for the construction and development of green water conservancy and ecological water conservancy. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the weir system according to an embodiment of the present invention.

[0026] Figure 2 This is a plan view of the weir system according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic flowchart of the sand flushing and silt removal method according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the sand flushing and silt removal process according to an embodiment of the present invention.

[0029] The components are: 1. Water storage area; 2. Sand collection module; 21. Sand collection bottom surface; 22. Streamlined sand drop slope surface; 3. Diversion weir module; 31. First streamlined diversion slope surface; 32. Weir top surface; 33. Second streamlined diversion slope surface; 4. Gate; 5. Culvert; 6. Protective coating. Detailed Implementation

[0030] The weir system of the present invention can be cast in situ on site, or prefabricated in the factory as precast components and then transported to the construction site for assembly, depending on the actual working conditions of the project.

[0031] Combination Figures 1-3 This invention provides an adaptive hydraulic automatic sediment flushing and silt removal weir system for installation within a channel, defining the inland end of the channel as the land end and the end connecting to the external sea as the near-shore end. The weir system includes a water storage area, a sediment collection module, and a diversion weir module arranged sequentially from the land end to the near-shore end.

[0032] The channels of this invention include, but are not limited to, drainage channels, tidal dams, open culverts, and covered culverts. The invention will now be described in detail using a channel as an example.

[0033] The diversion weir module comprises a weir crest, a first streamlined diversion slope facing the landward end, and a second streamlined diversion slope facing the nearshore end. The top elevation of the diversion weir module is lower than the bottom elevation of the reservoir area, and the weir crest is equipped with a gate for controlling the flow of water within the channel. The diversion weir module is adaptable to bidirectional tidal flow, with both high and low tides. The lower elevation of the diversion weir crest ensures smooth bidirectional flow of water and sediment along the streamlined diversion slope, eliminating the blind spot for sediment removal at the bottom of traditional weirs. Simultaneously, its structure does not encroach on the flood discharge cross-section and will not obstruct flood control, drainage, or tidal water exchange within the channel. The diversion weir module as a whole integrates multiple functions, including flow rectification, sediment guidance, and flow control, adapting to complex tidal flow patterns.

[0034] The first streamlined guide slope, the weir crest, and the second streamlined guide slope smoothly transition together. The curvature of both the first and second streamlined guide slopes gradually increases from their respective bottom edges to their top edges, reaching a peak curvature within 60% to 70% of their total horizontal projection length. Subsequently, the curvature gradually decreases and smoothly connects to the weir crest. The curvature of the weir crest does not exceed 20% of the peak curvature of either the first or second streamlined guide slope. The slope of both the first and second streamlined guide slopes from their bottom edges to the peak curvature is 1:30 to 1:5.0, and the slope from the peak curvature to the top edge is 1:1.5 to 1:2.5. The slope of the top surface is ≤1:20. The gradually curvature slope can reduce turbulent eddies during high tide, promote gravity settling and sediment collection, and confine and pressurize water during low tide to form a stable jet, eliminating the blind spot of sand accumulation at the bottom of the weir. If a single straight slope is used, it is prone to defects such as eddies, attenuation of sand flushing velocity, and sediment residue accumulation.

[0035] The bottom elevation of the sand collection module is lower than that of the bottom elevation of the first streamlined guide slope. The sand collection module includes a sand collection bottom surface and a streamlined sand-falling slope surface. One side of the sand collection bottom surface smoothly transitions to the water storage area via the streamlined sand-falling slope surface, while the other side smoothly transitions to the first streamlined guide slope surface. The curvature of the streamlined sand-falling slope surface gradually increases from the sand collection module towards the water storage area, reaching a peak curvature, and then gradually decreases, smoothly connecting to the water storage area. The peak curvature of the streamlined sand-falling slope surface is located within 50% to 65% of the horizontal length from the edge of the sand collection bottom surface. The slope of the section from the bottom edge of the streamlined sand-falling slope surface to the peak curvature is 1:2.0 to 1:3.5. The steep slope relies on gravity to propel the settled sediment completely into the bottom of the sand collection module, preventing the accumulation of mud in local depressions on the slope surface. The streamlined sand-falling slope has a gradient of 1:4.0 to 1:6.0 from the peak of curvature to the edge of the slope. The gentle slope reduces water flow turbulence and facilitates the full settling of suspended sediment. This segmented slope, combined with the gradual curvature, ensures that suspended sediment in the entire water storage area slides down the slope without lingering and reaches the sediment collection module.

[0036] The sand collection module adopts a transverse continuous groove structure with a groove depth of 0.4–1.0 m. Prefabricated standard single-section lengths are 3 m or 6 m, arranged along the channel bed surface. It can be spliced ​​to fit any size channel. Unlike the point-like sand flushing funnel structure of reservoirs, it can match the linear siltation characteristics of channels to achieve full-section sand collection. The maximum sand collection volume of the sand collection module in a single tidal cycle is V = L × B × H, where L is the length of the sand collection groove, B is the net width of the sand collection groove, and H is the effective depth of the sand collection groove. It also satisfies V ≥ 1.2 × S × Qin, where S is the sediment content of the water body, and Qin is the total inflow during a single high tide. By differentially setting the groove length and depth of the sand collection module, combined with parameters such as tidal range, water sediment content, and sediment particle size, the maximum sand collection volume in a single cycle can be determined, thereby achieving adaptive control of sand cleaning frequency and sand collection capacity.

[0037] The bottom surface of the sand collection area is either a flat surface or a concave arc surface with a radius of ≥1.2m to avoid the retention of mud and sand at the corners of the trough.

[0038] Both the diversion weir module and the sand collection module can be coated with a protective coating that is low-resistance and resistant to seawater abrasion. This coating has the characteristics of surface roughness, high abrasion resistance, and seawater corrosion resistance. On the one hand, it reduces the adhesion of sediment to achieve auxiliary silt prevention. On the other hand, it can withstand the continuous scouring of the high sediment content and high flow velocity bidirectional water flow in the coastal area for a long time, making it suitable for complex coastal operating environments.

[0039] The water storage area can be directly converted from the existing space of the canal and culvert without additional land occupation or large-scale civil engineering excavation. The water storage area is connected to a streamlined transition slope that smoothly connects with the sediment collection module. By setting the effective water storage height of the water storage area, the pressure of the flushing water flow and the jet velocity can be precisely controlled, flexibly adapting to coastal marine sediment environments with different sediment contents and different tidal levels.

[0040] This system relies on the tidal rise and fall sequence to form a closed-loop hydraulic cycle. The sediment flushing process is mainly achieved by controlling the opening and closing of the gates and their opening degree. It can adopt a multi-mode compatible or selectable control architecture: one is a semi-automatic operation mode triggered by remote terminal signals, which can adapt to the needs of maintenance personnel for on-site debugging, emergency intervention and remote centralized management in multiple scenarios; the other is to connect to the system's built-in preset logic control unit, which can automatically complete the gate opening and closing actions according to the pre-configured timing, water level, flow and other related triggering conditions. The entire process can be fully automated without human intervention, fully balancing the flexibility of system operation and the degree of automation.

[0041] Combination Figure 3 and Figure 4 The sand flushing and silt removal methods of this system include: The system obtains the high tide level. When the high tide level rises to the first preset water level (the first preset water level is not lower than the top elevation of the diversion weir module), the gate is opened to allow the sediment-laden tidal current from the open sea to enter the storage area. Some of the sediment from the sediment-laden tidal current settles in the sediment collection module beforehand. This stage is the high tide sediment collection stage. When the open sea tide level is higher than the water level inside the culvert, the gate is opened, and the high sediment-laden tidal current from the open sea enters the culvert. Due to gravity and the elevation difference between the storage area and the diversion weir module, large particles of sediment settle first, are blocked, and are collected in the sediment collection module, completing the pre-collection of sediment.

[0042] The system obtains the ebb tide level. When the ebb tide level drops back to the preset water storage height, the gate is closed, allowing the remaining sediment to settle throughout the entire area. Some of the sediment is then collected in the sediment collection module. This stage is the ebb tide stage of graded water storage. During the ebb tide cycle, the water level in the canal drops synchronously with the tide level in the open sea. When the water level drops back to the preset water storage height, the gate is closed, trapping the water in the canal storage area. The remaining suspended sediment in the water flow gradually settles. With the help of the streamlined sediment settling slope and the first streamlined guiding slope, the sediment can be collected in the sediment collection module, completing the full-area sediment collection.

[0043] When the ebb tide continues to drop to the second preset water level (the second preset water level is not higher than the top elevation of the diversion weir module, and can be further limited to not higher than the bottom elevation of the channel to ensure a sufficiently large water level difference between the upstream and downstream), the gate is opened and the gate opening is adjusted. The water level difference generates a flushing flow, flushing the sediment settled in the sediment collection module along the diversion weir module. This stage is the dynamic pressure regulation flushing stage. After the open sea tide drops to the bottom elevation of the channel, the gate is opened slightly and locally. Utilizing the stable water level difference formed between the upstream and downstream of the diversion weir module, the water in the storage area is rapidly discharged to form a high-intensity sweeping jet, which powerfully stirs up the silt accumulated in the sediment collection module and flushes it outward along the diversion weir module. As the water level in the storage area gradually decreases, the water level difference between the upstream and downstream decreases synchronously. The system is linked to slightly narrow the gate opening, dynamically maintaining a certain range of stable flushing water pressure and flow velocity to ensure a uniform and stable flushing effect throughout the process.

[0044] The water level of the sediment collection module is obtained. When the water level of the sediment collection module drops to the third preset water level (the third preset water level is not higher than the top surface elevation of the diversion weir module), the gate is closed. This stage is the cycle reset stage. When the water level in the storage area drops to the bottom of the culvert, the gate is completely closed, the current round of sediment flushing operation ends, the system enters standby mode, and waits for the next tidal cycle to automatically restart the cycle.

[0045] The timing control of this system includes two implementation methods that can operate independently or be combined to form a collaborative verification mode. The specific timing control logic is as follows: First, a timed triggering method based on tidal forecast reports. This method relies on pre-entered tidal forecast data for the target area and triggers the signal by matching the time node corresponding to the preset tide level. It can operate stably without relying on on-site water level monitoring devices. The second method is a real-time water level status triggering method. This method continuously collects real-time water level data and triggers the signal when the water level reaches a preset threshold, matching the actual tidal state and water level status on-site. Alternatively, a dual-logic collaborative verification module can be enabled. In this mode, the system will only trigger when the preset trigger time of the tidal forecast report is reached and the real-time water level status simultaneously meets the corresponding preset conditions. This minimizes environmental deviations and misjudgments that may occur under a single logic, further improving the reliability and accuracy of the system.

[0046] The gate opening control of this system can be achieved in the following two ways: One is the tidal time-series segmented preset control method. Based on the measured tidal process curves of the target area over many years, the sand flushing process is divided into multiple time-series intervals. Each segment corresponds to a fixed gate opening that is pre-stored to match the average water level difference. This method is suitable for canal and culvert systems that are not equipped with water level monitoring devices.

[0047] The second method is a closed-loop automatic control system based on water level monitoring. This system uses a water level monitoring device to collect real-time data on the water level inside the storage area and the tide level at the nearshore end, calculating the dynamic water level difference ΔH. The controller then adjusts the gate opening using an opening control equation. As the water level difference ΔH gradually decreases, the gate opening is linearly narrowed to stabilize the flushing velocity within the target range. The opening control equation is: b(ΔH) = In the formula: b(△H) is the effective flow opening (m) of the gate that dynamically changes with the water level difference, and is the variable to be controlled; μ is the gate orifice flow coefficient, with a value of 0.58 to 0.68; B 渠 Where is the net width of the culvert (m); g is the acceleration due to gravity (9.81 m / s²). 2 ); △H is the real-time water level difference (m) between the inner side of the reservoir and the offshore tide level at the nearshore end, which is the dynamic head that generates the sediment flushing jet; Q is the real-time total discharge (m³) from the reservoir downstream at the current moment. 3 / s).

[0048] The real-time total flow rate Q released downstream from the water storage area at the current moment can be determined using the following two methods: First, instantaneous cross-sectional flow velocity and water depth are collected using channel cross-sectional velocity monitoring devices and water level monitoring devices, and the instantaneous discharge rate is calculated in real time using the cross-sectional integral method. In the formula: v 实 h represents the measured flow velocity at the cross-section within the channel. 内 This represents the real-time water depth of the storage area. This method is applicable to automatic control conditions, where the controller calculates the depth in real time and inputs it into the opening control equation.

[0049] Secondly, by pre-setting the maximum water storage volume V of the water storage area 存 Total duration of a single standard discharge (T) 泄 The estimated average discharge current Q is used as a fixed input value for segmented timing control: This method is applicable to simple culverts without real-time flow velocity monitoring.

[0050] The gate opening adjustment is subject to strict constraints: the minimum effective gate opening is ≥0.15m to prevent the bottom of the gate from sticking and jamming against the guide weir module; the maximum gate opening does not exceed 70% of the net height of the channel culvert to avoid instantaneous high-flow dilution of the jet and reduce the shear scouring force of the bottom sediment. The gate opening adjustment adopts a smooth linear adjustment method to avoid violent water flow oscillations that disturb the sediment and prevent secondary sedimentation and accumulation in the sediment collection module.

[0051] The system's sand flushing and silt removal operations are mainly scheduled for routine operation during the dry season. During the flood season, priority is given to ensuring the core functions of flood control and drainage in the channel. During the flood season, only the basic silt prevention function is retained, and no concentrated sand flushing is carried out.

[0052] It should be specifically noted that the hardware control circuit and the accompanying software control program used to implement the system operation in this invention are both existing technologies well known to those skilled in the art. The component selection, electrical connection architecture, and corresponding software program logic of the hardware control circuit have been fully disclosed in numerous published patent documents, industry standards, and technical manuals. Those skilled in the art can directly reproduce and adapt the technology without creative effort, combining conventional technical means in the field. This specification focuses on describing the core improvements of this application that distinguish it from the prior art, without redundantly describing the specific wiring layout of the general hardware circuit, the parameters of the underlying components, or the source code details of the general control software. This omission will not prevent those skilled in the art from fully implementing the technical solution protected by this application based on the complete technical solution disclosed in this specification.

[0053] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail to the invention without departing from the spirit and scope of the invention as defined in the appended claims are within the scope of protection of the invention.

Claims

1. An adaptive hydraulic automatic sediment flushing and silt removal weir system, characterized in that, It is used to be installed in a channel, wherein the end of the channel closer to the inland is the land end, and the end connecting to the external sea area is the near-sea end; The dam system includes a water storage area, a sediment collection module, and a diversion weir module arranged sequentially from the land end to the near-sea end; The diversion weir module includes a weir top surface, a first streamlined diversion slope facing the land end, and a second streamlined diversion slope facing the near-sea end; the weir top surface is equipped with a gate for controlling the flow of water in the channel; the top surface elevation of the diversion weir module is lower than the bottom surface elevation of the water storage area. The sand collection module includes a sand collection bottom surface and a streamlined sand falling slope surface; one side of the sand collection bottom surface is smoothly connected to the water storage area through the streamlined sand falling slope surface, and the other side is smoothly connected to the first streamlined flow guiding slope surface; the bottom elevation of the sand collection module is lower than the bottom elevation of the first streamlined flow guiding slope surface.

2. The adaptive hydraulic automatic sediment flushing and siltation weir system according to claim 1, characterized in that, The curvature of both the first and second streamlined guide slopes gradually increases from their respective bottom edges to their top edges, reaching a peak curvature within 60% to 70% of their total horizontal projection length. Subsequently, the curvature gradually decreases and smoothly connects to the weir crest surface. The curvature of the weir crest surface does not exceed 20% of the peak curvature of either the first or second streamlined guide slope. The slope of the first streamlined guide slope and the second streamlined guide slope from the bottom edge to the peak curvature is 1:30 to 1:5.0, and the slope from the peak curvature to the top edge is 1:1.5 to 1:2.

5. The slope of the top surface is ≤1:

20.

3. The adaptive hydraulic automatic sediment flushing and siltation weir system according to claim 1, characterized in that, The curvature of the streamlined sand-falling slope gradually increases from the sand-collecting module towards the water storage area to a peak curvature, then gradually decreases and smoothly connects to the water storage area. The peak curvature of the streamlined sand-falling slope is located within 50% to 65% of the horizontal length from the bottom edge of the sand-collecting module. The slope of the streamlined sand-falling slope from the bottom edge to the peak curvature is 1:2.0 to 1:3.5, and the slope from the peak curvature to the top edge is 1:4.0 to 1:6.

0.

4. The adaptive hydraulic automatic sediment flushing and siltation weir system according to claim 3, characterized in that, The sand collection module is a transverse continuous groove structure with a groove depth of 0.4 to 1.0 m. The maximum sand collection volume of a single tide is V = L × B × H, where: L is the length of the sand collection groove, B is the net width of the sand collection groove, and H is the effective depth of the sand collection groove. At the same time, it satisfies V ≥ 1.2 × S × Qin, where: S is the sand content of the water body, and Qin is the total amount of inflow in a single high tide.

5. The adaptive hydraulic automatic sediment flushing and silt removal weir system according to claim 1, characterized in that, The surfaces of the diversion weir module and the sand collection module are coated with a low-resistance, seawater-resistant protective coating.

6. The adaptive hydraulic automatic sediment flushing and siltation weir system according to claim 1, characterized in that, It also includes a water level monitoring device for monitoring water level changes in the channel and a controller for receiving signals from the water level monitoring device and controlling the opening and closing of the gate; the channel is one of a sea discharge culvert, a tidal gate dam, an open culvert, and a culvert; at least the sand collection module and the diversion weir module are prefabricated components.

7. A method for flushing and silting sediment, using a weir system as described in any one of claims 1 to 6, characterized in that, include: The high tide level is obtained. When the high tide level rises to the first preset water level, the gate is opened to allow the sediment-laden tidal current from the open sea to enter the water storage area. Some of the sediment from the sediment-laden tidal current settles in the sediment collection module in advance. The first preset water level is not lower than the elevation of the top surface of the diversion weir module. The sluice gate is closed when the ebb tide level drops back to the preset water storage area height, allowing the remaining sediment to settle throughout the area, with some sediment being collected in the sediment collection module. When the ebb tide level drops back to the second preset water level, the gate is opened and the gate opening degree is adjusted. The water level difference generates a sand flushing flow, which flushes the sediment settled in the sand collection module out along the guide weir module. The second preset water level is not higher than the top surface elevation of the guide weir module. The water level at the sediment collection module is obtained. When the water level at the sediment collection module drops to the third preset water level, the gate is closed. The third preset water level is not higher than the elevation of the top surface of the diversion weir module.

8. The method according to claim 7, characterized in that, The method for regulating the gate opening is either a tidal time-series segmented preset regulation method or a water level monitoring closed-loop automatic control method; The aforementioned tidal timing segmented preset control method is as follows: based on the measured tidal process curves of the target area over many years, the sediment flushing process is divided into multiple time intervals, and a fixed gate opening corresponding to the average water level difference of each interval is pre-stored and matched. The aforementioned closed-loop automatic control method for water level monitoring is as follows: the water level inside the water storage area and the tide level in the nearshore sea are collected in real time by the water level monitoring device, the dynamic water level difference ΔH is calculated in real time, and the gate opening is controlled by the controller through the opening control equation to stabilize the sand flushing velocity within the target range. The opening control equation is: b(△H) = In the formula: b(△H) is the effective flow opening of the gate that dynamically changes with the water level difference; μ is the gate orifice flow coefficient, with a value of 0.58 to 0.68; B 渠 denoted as the channel width; g is the gravitational acceleration; ΔH is the real-time water level difference between the inner side of the reservoir and the offshore tide level at the nearshore end; Q is the real-time total discharge from the reservoir downstream at the current moment.

9. The method according to claim 7, characterized in that, The method for determining the real-time total flow rate Q released downstream from the water storage area at the current moment is as follows: Instantaneous cross-sectional flow velocity and water depth are collected using channel cross-sectional velocity monitoring devices and water level monitoring devices. The instantaneous discharge rate is then calculated in real time using the cross-sectional integral method. In the formula: v 实 h represents the measured flow velocity at the cross-section within the channel. 内 Real-time water depth of the reservoir area; Alternatively, by pre-setting the maximum water storage volume V of the water storage area. 存 Total duration of a single standard discharge (T) 泄 The estimated average discharge current Q is used as a fixed input value for segmented timing control: .

10. The method according to claim 7, characterized in that, The second preset water level is not higher than the elevation of the bottom surface of the channel; The hard limit for gate opening control is: the minimum effective gate opening is ≥0.15m, and the maximum gate opening does not exceed 70% of the channel's net height; The high tide level and low tide level are obtained through tide forecast reports or water level monitoring devices.

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