Dyke burst closure construction method

Abstract

Disclosed in the present application is a dyke burst closure construction method, comprising: pulling two ends of a closure net; guiding same to a burst by means of a water flow; stretching same at the front end of the burst to form a closure, the closure net comprising an integrated trunk net and two corner nets, the trunk net extending from the front end of the burst to a downstream area, the two corner nets being formed by extending the bottom of the trunk net towards diagonal outer sides, the bottom of the trunk net being provided with an arc-shaped net bottom, and the opening of the trunk net being inclined upwards; throwing vacuum soil bags to first settle and block two sides of the lower end of the burst, and then accumulate inside the trunk net in the downstream area, thereby narrowing and closing the water flow; and keeping throwing until the burst is completely filled.

Description

A method for constructing the closure section of a dam breach Technical Field

[0001] This application relates to the field of dam closure in water conservancy projects, and in particular to a construction method for closure of dam breaches. Background Technology

[0002] The main methods for plugging breaches in river dikes are: driving piles into the breach and then filling them with soil in straw bags; sinking vehicles or boats into the breach and then dumping soil and rocks; and filling the breach with wire mesh and throwing stones into the breach. These methods are not only costly, labor-intensive, and dangerous, but also difficult to implement when the breach is large, the water flow is rapid, or the water is deep. Driving piles is difficult, and sinking vehicles or boats and dumping stones often result in the breach being washed away by the strong resistance and unstable foundation. All of these methods are insufficient to solve the problem of flood control and water diversion when the breach is closed.

[0003] The inventor is aware of a method that uses steel or flexible mesh to block and divert water flow. The steel or flexible mesh is supported and fixed by ropes. However, since the spur formed by filling the breach is independent of the original dam, it cannot disperse the water pressure. The spur is built without a foundation, and the water pressure it experiences is provided by the friction at the bottom of the spur and the supporting force of the mesh. The mesh provides support through tension, making the spur section a weak point that is prone to breaching again. In addition, the effective deployment and fixation of the flexible mesh is crucial for closing the breach, as the water flow velocity at the breach is high, making deployment and fixation difficult. Summary of the Invention

[0004] The purpose of this application is to overcome the deficiencies of the prior art and provide a construction method for the closure of a dam breach, so as to solve one or more problems mentioned in the background art.

[0005] To achieve the above objectives, the technical solution of this application is as follows: A method for constructing a dam breach closure, wherein a flow-blocking net is pulled at both ends, and the water flow guides it from the upstream low-velocity zone to the breach. The opening of the flow-blocking net is then stretched at the front end of the breach to form an interception. The flow-blocking net comprises an integral main net and two corner nets. The cross-sectional area of ​​the main net is adapted to the cross-sectional area of ​​the breach. The main net extends from the front end of the breach into the downstream area beyond the rear end. The two corner nets are formed by extending obliquely outward from the bottom corners of the main net. An arc-shaped bottom is provided at the bottom of the main net for transitional connection between the two corner nets. Two corner nets are symmetrically positioned on either side of the breach's centerline. The front end of the main net has an upward-sloping opening, with floats evenly distributed along the upper edge and several weights evenly tied along the lower edge. The opening is tensioned and fixed by a net tensioning system. Vacuum bags are thrown into the opening, moving within the main net under the impact of the water flow. Driven by lateral water flow or guided by the curved bottom of the net, they gradually sink to the lower sides of the breach and are intercepted and fixed by the corner nets. Vacuum bags are continuously thrown in, and after the corner nets are full, they gradually accumulate within the main net in the downstream area, narrowing the water flow and achieving interception. The throwing continues until the breach is completely filled.

[0006] In one embodiment, the system also includes an integrally structured diversion net. The diversion net is formed by the lower edge of the opening and the outer edges of both sides of the intercepting net. The diversion net has a double-layer structure, with a high-strength dense mesh net as the lower layer and a woven fabric as the upper layer. The diversion net includes a bottom-laying net and a side-pulling net. The bottom-laying net is laid on the bottom of the breach front, and the side-pulling net is laid on the dikes on both sides. The bottom-laying net is tensioned by a bottom-laying anchor anchored in the upstream low-velocity zone, and the side-pulling net is anchored to the dike or bank foundation.

[0007] In one embodiment, the bottom net has a fan-shaped structure, and its laying area extends symmetrically to both sides from the direction before the breach. Several circular weight lines are set at the bottom of the bottom net. The weight lines are parallel to each other. In areas with higher water flow velocity, the spacing between adjacent weight lines is smaller. Weights are evenly tied to the weight lines to ballast the bottom net.

[0008] In one embodiment, the mesh tensioning system includes side edge tensioning anchors, suspension ropes, top ropes, and pre-embedded rods embedded in the embankments on both sides. The two ends of the top ropes are anchored to the embankments and tensioned by fixed pulleys at the top of the pre-embedded rods. The mesh opening of the main mesh is suspended below the top ropes by several suspension ropes. The side edge tensioning anchors connect the two sides of the mesh opening and are anchored in the upstream low-speed zone.

[0009] In one embodiment, before the intercepting net is tensioned, obstacles on both sides of the breach are cleared, the breach is widened if necessary, and a new dike is rebuilt, with pre-embedded rods pre-embedded on the new dike.

[0010] Compared with existing technologies, the dam breach closure construction method of this application has the following beneficial effects: The closure of the breach is achieved by using a novel intercepting net combined with flexible fill material. The intercepting net, after being pulled upstream, is guided by the water flow to the breach and quickly and effectively unfolds, improving the success rate of the interception setup. Utilizing the settling characteristics of water-carried materials, the intercepting net is equipped with corner nets. Under the action of the water flow and the guidance of the arc-shaped net bottom, the fill material settles and is intercepted within the corner nets, continuously narrowing the breach from both sides and forming a horn structure as support during and after the closure, improving the closure success rate and the strength of the dam's supporting structure after closure. With the same amount of fill material, the supporting structure has higher bearing capacity, reducing the probability that the breach will become a breach point again. The intercepting net moves the breach closure position downstream, reducing the impact of the high-speed water flow on both sides of the breach's front end. Closure can also be carried out under normal embankment conditions, shortening the construction period for breach closure and emergency repairs. Attached Figure Description

[0011] Figure 1 is a top view of the tensioned intercepting net according to one or more embodiments of this application;

[0012] Figure 2 is a front view schematic diagram of the tensioning structure of the intercepting net bag according to one or more embodiments of this application;

[0013] Figure 3 is a side view of the tensioned intercepting net according to one or more embodiments of this application.

[0014] In the diagram: 1. Interception net; 11. Net opening; 12. Corner net; 13. Main net; 2. Newly built dike; 3. Original dike; 4. Bottom net; 41. Weight line; 5. Net opening tensioning system; 51. Suspension rope; 52. Top rope; 53. Embedded pole; 54. Side tensioning anchor; 6. Bottom net tensioning anchor; 7. Side tensioning net; 8. Vacuum soil bag; 9. Corner net anchoring system. Detailed Implementation

[0015] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely the best embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] As an embodiment of this application, this application provides a method for constructing a dam breach closure joint. A diversion net 1, as shown in Figures 1, 2, and 3, is used to intercept the breach fill material. The fill material is a flexible material; in one embodiment, vacuum soil bags 8 are used. Addressing the problems of high water flow velocity at the breach, ineffective deployment of the interception net, and insufficient support for the dam embankment, this application proposes a structure for the diversion net 1 suitable for constructing a diversion embankment and a corresponding method for constructing the breach closure joint. The specific steps include:

[0017] Step 1: Inspect the condition of the dikes on both sides of the breach, remove obstacles and repair them. If the condition of the dikes on both sides of the breach is not good, the breach may be widened if necessary, and a new dike may be rebuilt. Embedded rods 53 are pre-embedded on the new dike.

[0018] Step Two: Since the water flow velocity increases closer to the breach, to better deploy the intercepting net 1, two traction points are arranged in the upstream low-speed zone, connecting to both ends of the net opening 11. Several floats are evenly distributed along the upper edge of the net opening 11, and several weights are evenly tied along the lower edge. During traction, the upper edge of the net opening 11 is parallel to the water surface, and its lower edge is guided along the bottom to the breach. Combined with the traction forces on both sides, the net opening 11 effectively... Unfold and slowly release the traction rope. Under the action of the water flow, the intercepting net 1 is guided into the breach and covers the entire front end of the breach to form a barrier. After the intercepting net 1 is guided into the breach, it is tensioned by the side edge tensioning anchors 54 connected to both ends of the intercepting net 1 and anchored in the low-speed water flow zone upstream. The side edge tensioning anchors 54 are equipped with floats on the anchors to facilitate position adjustment when the anchor is raised as needed. Finally, the net opening 11 is tensioned and fixed by the net opening tensioning system.

[0019] As shown in Figures 1-3, the intercepting net 1 is integrally woven and consists of a main net 13 and two corner nets 12. When fully unfolded, the cross-sectional area of ​​the main net 13 should be greater than or equal to the cross-sectional area of ​​the breach channel. The main net 13 serves as the main intercepting net, with its opening 11 positioned at the front end of the breach. Its body extends along the breach channel and extends downstream to the rear end of the breach. The two corner nets 12 are formed by extending obliquely outward from the bottom corner of the main net 13. Utilizing the characteristics of water flow impact and settling, the impacted fill material preferentially settles within the corner nets 12. The two corner nets 12 are symmetrically positioned at the breach... On both sides of the center line of the breach, and with the bottom of the main net 13 arc-shaped transition connecting the two corner nets 12, the fill material falling with the water flow at the bottom of the arc-shaped net is preferentially guided into the corner net 12 until the corner net 12 is completely filled, forming a water flow opening with sufficient lateral support downstream, so that subsequent fill material can continuously advance towards the center to intercept the flow; thus, it can be seen that the closure of the intercepting net 1 should be located downstream of the actual breach, most likely in the bottom area of ​​the net. In this way, the impact of high-speed water flow on the dikes on both sides of the breach is small. Understandably, the construction of new dikes 2 or the setting of dike caps is not a necessary step, which can effectively reduce the time required for emergency rescue.

[0020] As shown in Figure 1, the front end of the net 13 is an upward-sloping mesh opening 11 to facilitate the accurate placement of vacuum soil bags 8. The placement should be carried out alternately or simultaneously from both sides. The placed vacuum soil bags 8 move within the net 13 under the impact of the water flow. Driven by the lateral water flow or guided by the arc-shaped bottom of the net, they gradually slow down and sink on both sides of the lower end of the breach, and are intercepted and fixed by the corner net 12, gradually forming a symmetrical narrowing and supporting angular structure.

[0021] Vacuum bags 8 are continuously thrown in. After the corner net 12 is filled, the vacuum bags 8 gradually accumulate in the main net 13 in the downstream area, narrowing the water flow diameter and achieving interception. The throwing continues, and the throwing point can be adjusted appropriately according to the settlement and accumulation of vacuum bags 8 in the interception net 1 to control the uniformity of settlement on both sides. The position of the closure opening is also manually adjusted until the main net 13 is completely filled and the breach is completely sealed. A dike with a corner support structure is formed in the interception net 1. Compared with the existing dikes built by planar mesh interception, it has a greater strength to withstand water pressure and is less likely to become a breach again.

[0022] To stabilize the corner support structure of the dike, a corner net anchoring system 9 is set on the outer side of the corner net 12. The anchoring points of the corner net anchoring system 9 are located on the dike embankment. It is laid and anchored when the intercepting net bag 1 is tensioned. As the corner net 12 is filled, the impact force of the water flow on the corner net 12 and the vacuum soil bag 8 inside can be dispersed to the dike embankment on both sides.

[0023] In order to stretch the lower and side edges of the mesh opening 11, prevent the bottom or side escape zone of the intercepting net 1, and reduce the scouring of the bottom and the front edge of the dike by the high-speed water flow, the intercepting net 1 is also integrally woven with a guide net, as shown in Figures 1 and 2. The guide net is formed by the extension of the lower edge and the side edges of the mesh opening 11 of the intercepting net 1. The guide net has a double-layer structure. The lower layer is a high-strength dense mesh net, which serves as a load-bearing net, and the upper woven fabric serves as a filter layer to reduce water resistance.

[0024] The diversion net includes a bottom-laid net 4 and a side-pull net 7. The bottom-laid net 4 has a fan-shaped structure and is laid on the bottom of the water at the front of the breach. Its laying area extends symmetrically to both sides from the front of the breach, forming a fan-shaped diversion bottom surface at the front of the breach to adapt to the stepped water velocity distribution characteristics at the front of the breach. The side-pull net 7 is laid on the embankments on both sides and is formed by folding the bottom-laid net 4. It is used to protect the eroded embankment surface. The side-pull net 7 is anchored to the embankment or bank foundation in the low-velocity water flow zone on both sides after being evenly tensioned by pull ropes.

[0025] The tensioning system 5 includes tensioning of the side tensioning net 7, tensioning of the bottom laying net 4, side tensioning anchor 54, suspension rope 51, top tensioning rope 52, and pre-embedded rods 53 buried on both sides of the embankment.

[0026] Among them, the bottom net 4 is tensioned by the bottom net tensioning anchor 6 anchored in the upstream low-speed zone. The bottom net tensioning anchor 6 is evenly distributed along the arc-shaped edge of the outer edge of the bottom net 4 and is stretched perpendicular to the arc-shaped edge at each point. The anchor point of each bottom net tensioning anchor 6 should be located at the bottom of the upstream low-speed zone to improve tensioning stability. In addition, referring to Figure 1 again, the bottom net 4 should be equipped with ballast to fit the bottom surface. Several ring-shaped weight lines 41 concentric with the center of its own fan-shaped surface are set at the bottom of the high-strength dense mesh of the bottom net 4. The weight lines 41 are parallel to each other. The higher the water flow velocity, the smaller the arrangement distance between adjacent weight lines 41. Weights are evenly distributed on the weight lines 41.

[0027] The tensioning of the upper edge of the mesh opening 11 is achieved through the suspension rope 51, the upper pull rope 52 and the pre-embedded rod 53, as shown in Figures 2 and 3. The pre-embedded rod 53 is pre-embedded on the newly built embankment 2 or piling on the original embankment 3. The top of the pre-embedded rod 53 is equipped with a fixed pulley. The two ends of the upper pull rope 52 are anchored to the embankment and tensioned by the fixed pulley at the top of the pre-embedded rod 53, forming a horizontal suspension rope between the two pre-embedded rods 53. The mesh opening 11 of the net 13 is connected by several evenly distributed suspension ropes 51 and is vertically suspended on the horizontal suspension rope above.

[0028] Among them, the vacuum soil bag 8, which is used as flexible dumping material, contains small particles of soil vacuum-sealed inside. It consists of at least a geotextile bag, a vacuum plastic bag, and a high-strength polyester fiber flexible bag from the inside out. Each of the three bags has a certain amount of surplus to facilitate adaptive deformation. The vacuum plastic bag has the largest surplus, the geotextile bag has a medium surplus, and the high-strength polyester fiber flexible bag has the smallest surplus. The soil is crushed and sieved (to remove small stones, debris, plants, etc.), and then dried or watered to the optimal moisture content, which is controlled between 8% and 25%. This facilitates the plastic deformation and fusion of soil particles during the self-compacting process. After dumping and piling, atmospheric pressure, water pressure, and the pressure of accumulation and compression cause it to self-compact. The vacuum soil bags 8 undergo adaptive deformation among themselves, improving the airtightness of the dike. After long-term accumulation, a stable overall structure is formed.

[0029] The directional terms “upper,” “lower,” “front,” “back,” “inner,” and “outer” used in this application are described in accordance with the directions and orientations shown in the corresponding figures in Figures 1-3. These terms are primarily for the purpose of better describing this application and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0030] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in certain situations to indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0031] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a closure gap of a dam breach, characterized in that: By pulling the two ends of the intercepting net, the water flow guides it from the upstream low-velocity zone to the breach. The opening of the intercepting net is stretched at the front end of the breach to form an interception. The intercepting net includes an integral main net and two corner nets. The cross-sectional area of ​​the main net is adapted to the cross-sectional area of ​​the breach. The main net extends from the front end of the breach into the downstream area beyond the rear end. The two corner nets are formed by extending obliquely outward from the bottom corners of the main net. The bottom of the main net has an arc-shaped base for transitional connection between the two corner nets. The two corner nets are symmetrically arranged on both sides of the breach centerline. The front end of the net is an upward-sloping opening. Floats are evenly distributed along the upper edge of the opening, and several weights are evenly tied along the lower edge. The opening is tensioned and fixed by a net tensioning system. Vacuum soil bags are thrown into the opening. Under the impact of the water flow, the vacuum soil bags move within the net and are gradually sank to the lower end of the breach by the lateral water flow or the guidance of the arc-shaped net bottom, and are intercepted and fixed by the corner net. Vacuum soil bags are continuously thrown in. After the corner net is filled, the vacuum soil bags gradually accumulate in the net in the downstream area, narrowing the water flow diameter and achieving interception. Throwing continues until the breach is completely filled.

2. The construction method for the closure of a dam breach according to claim 1, characterized in that: It also includes an integrated diversion net, which is formed by the lower edge and the outer edges of the intercepting net. The diversion net has a double-layer structure, with a high-strength dense mesh lower layer and a woven fabric upper layer. The diversion net includes a bottom-laying net and a side-pulling net. The bottom-laying net is laid on the bottom of the breach front, and the side-pulling net is laid on the dikes on both sides. The bottom-laying net is tensioned by a bottom net tensioning anchor anchored in the upstream low-velocity zone, and the side-pulling net is anchored to the dike or bank foundation.

3. The construction method for the closure of a dam breach according to claim 2, characterized in that: The bottom net has a fan-shaped structure, and its laying area extends symmetrically to both sides from the direction before the breach. Several circular weight lines are set at the bottom of the bottom net. The weight lines are parallel to each other. In areas with higher water flow velocity, the spacing between adjacent weight lines is smaller. Weights are evenly tied to the weight lines to weigh down the bottom net.

4. The construction method for the closure of a dam breach according to claim 3, characterized in that: The mesh tensioning system includes side edge tensioning anchors, suspension ropes, top ropes, and pre-embedded rods embedded in the embankments on both sides. The two ends of the top ropes are anchored to the embankments and tensioned by fixed pulleys at the top of the pre-embedded rods. The mesh opening of the main mesh is suspended below the top ropes by several suspension ropes. The side edge tensioning anchors connect the two sides of the mesh opening and are anchored in the upstream low-speed zone.

5. The construction method for the closure of a dam breach according to claim 4, characterized in that: Before the intercepting net is tensioned, obstacles on both sides of the breach are cleared. If necessary, the breach is widened and a new dike is rebuilt. The pre-embedded rods are pre-embedded on the new dike.

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