Construction method for closure gap of closure embankment

Abstract

The closure gap construction method comprises the steps that a bottom protection blocking net is flatly laid and tensioned at the bottom of a closure gap, gravity points are distributed on the bottom protection blocking net in a dot matrix mode, the bottom protection blocking net is composed of woven cloth and high-strength dense-mesh net layers, and the bottom protection blocking net is provided with a blocking area and a bottom protection area; constructing embankments on two sides of the closure gap; the high-strength dense-mesh net in the blocking area is turned over to the outer side face of the embankment to tension and block the embankment; vacuum soil bags are thrown and filled, and the vacuum soil bags are thrown into the embankment through a bidirectional end entering method till closure; reinforcing and widening the embankment; the woven fabric in the blocking area of the bottom protection blocking net is turned over to the outer side face of the embankment and tensioned to form embankment inverted filtering; according to the construction method, bottom protection is conducted by tensioning the self-ballasting bottom protection blocking net, washing of water flow is reduced and dispersed, and the closing construction success rate is increased; the outer side part of the bottom protection blocking net is turned over to form a blocking part of the closure gap, and blocking operation is easy; after the vacuum soil bags are stacked, pressure self-compaction is achieved, adaptive deformation can improve the sealing effect and stacking strength of the embankment, and the vacuum soil bags and the flexible bottom protection blocking net are combined to achieve reliable closure.

Description

Technical Field

[0001] The invention relates to the field of plugging of marine engineering and water conservancy engineering, and in particular to a method for constructing a closure mouth of a dike. Background Art

[0002] Closing the cofferdam is a key step in land reclamation and river dike construction. As the cofferdam mouth becomes smaller, the water flow rate through the cofferdam mouth increases, which not only seriously affects the safety of construction workers, but also makes closing the cofferdam difficult. Especially when the water flow rate is large and the flow rate is high, the water level difference and water flow on both sides of the cofferdam mouth will cause great pressure on the cofferdam mouth, which will bring great difficulties to closing the cofferdam mouth.

[0003] The existing construction process of the closure mouth: the closure mouth is raised → the closure mouth is contracted → the closure mouth is sealed. In order to intercept the water flow, materials are thrown into the water in the closure mouth. In order to prevent the thrown materials from being eroded by the water flow, net bags are generally used for hoisting and weighting. The construction method is mostly flat plugging, or a steel frame cage is set to form a skeleton for positioning and blocking, and the flow is intercepted by throwing vertical plugs. Both methods have their own limitations. In order to prevent the loss of thrown materials, net bag throwing is required in the later interception when the water flow is large. Therefore, this method requires the construction of a floating bridge and the configuration of hoisting equipment to achieve it. The steel frame cage is thrown to intercept the vertical plug and it is easy to form a vertical axis vortex, which will cause a large scouring to the bottom of the closure mouth and the bottom of the downstream. Therefore, bottom protection construction is required to ensure successful closure.

[0004] Therefore, the existing technology of closure construction has a large amount of work, high construction intensity, low efficiency and high cost, and the construction method still needs to be studied and improved. In addition, the construction materials are generally stones or sandbags. With the control of sand and stone resources and the increase in costs, the economic benefits of using sand and stone for construction are relatively low. It is urgent to use readily available materials as a substitute and to study construction methods suitable for replacing construction materials. Summary of the invention

[0005] The object of the present invention is to overcome the defects of the prior art and provide a method for constructing the closure of a dike to solve one or more problems raised in the above-mentioned background technology.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] A method for constructing a closure mouth of a dike, comprising the following steps:.

[0008] S1. Lay and tighten the bottom protection net at the bottom of the preset dragon mouth. Several gravity points are fixed in a dot matrix on the bottom protection net. Gravity objects are set on the gravity points to load the bottom protection net. The bottom protection net is a double-layer structure, with the lower layer being woven fabric and the upper layer being a high-strength dense mesh. The bottom protection net includes an outer retaining area and an inner bottom protection area. The bottom protection area is laid at the bottom of the dragon mouth, and its laying area extends from the dragon mouth area to the dike area on both sides and the inner filling area. The retaining area is laid in the discharge area, and its width should be adapted to the height of the dike;

[0009] S2. Construct the dikes and weirs on both sides of Longkou, and further ballast the dikes and weirs to fix the bottom protection nets on both sides;

[0010] S3. The high-strength dense mesh of the bottom protection blocking area is turned up to the outer side of the dike and stretched to block the dragon mouth. The blocking area and the dragon mouth are surrounded on three sides to form a dragon mouth dumping area;

[0011] S4, dump vacuum earth bags into the dumping area to occupy the dike until the flow is completely cut off and the joint is closed;

[0012] S5. Continue to dump backfill toward the inner side of the dragon mouth to reinforce and widen the dike;

[0013] S6. Turn the woven fabric in the bottom protection net blocking area to the outer side of the dike and tighten it to form the inverted filter of the Longkou dike.

[0014] Furthermore, after the bottom protection net in step S1 is laid flat, it is tensioned by an anchor system, and the anchor system includes an outer anchor and an inner anchor that are arranged relatively to each other. The inner anchor tensions the inner end of the bottom protection net, and the outer anchor tensions the woven fabric of the bottom protection net and the outer ends of the high-strength dense mesh net respectively. Floating drums are arranged on the outer anchors to facilitate the anchoring of the high-strength dense mesh net and the woven fabric in the blocking area.

[0015] Furthermore, the bottom protection net blocking area in steps S3 and S6 are tensioned by a side tensioning system and an upper tensioning system. The side tensioning system tensions the left and right side ends of the blocking area, and the upper tensioning system tensions the upper end of the blocking area. The side tensioning system includes side tensioning ropes, embedded piles and rope locks. The embedded piles are embedded in the dike construction in step S2. Connecting arms are respectively arranged on the embedded piles at multiple preset elevations. The connecting arms extend to the outer side of the dike and are provided with rope locks. The side tensioning ropes are locked by the rope locks after tensioning. The upper tensioning system includes upper tensioning ropes, embedded rods and ground anchors. The embedded rods and ground anchors are both embedded in the dike construction in step S2. The embedded rods extend out from the top of the dike, and a fixed pulley is rotatably arranged on the top of the rods. The upper tensioning ropes are connected to the two corners of the upper edge of the blocking area. The upper tensioning ropes are wrapped around the fixed pulley and tensioned by locking the ends of the ground anchors.

[0016] Furthermore, the gravity object is a vacuum earth bag tied to a high-strength dense mesh.

[0017] Furthermore, the distribution of gravity points in the bottom protection area is denser than that in the retaining area. When filling in step S4, the bottom protection area as a whole is firstly filled evenly. Before the closure and diversion, the bottom protection area is further compressed and protected. After the closure, the bottom protection area inside the dike body is raised and filled to further compress and support the dike foot.

[0018] Furthermore, small soil particles are vacuum-sealed in the vacuum soil bag, and the bag body is composed of a geotextile bag, a vacuum plastic bag, and a high-strength cloth bag from the inside to the outside.

[0019] Compared with the prior art, the closure construction method of a dike dam of the present invention has the following beneficial effects:

[0020] The closure mouth construction method uses a tensioned and self-ballasted bottom protection net to protect the dragon mouth and the bottom inside and outside the dragon mouth, improves foundation conditions, reduces and disperses the scouring of the dragon mouth, i.e., the bottom inside and outside the dragon mouth, and improves the success rate of the closure construction; the outer part of the bottom protection net is turned up to form a barrier at the dragon mouth, which is easy to carry out the blocking operation, and the thrown filling material is blocked by the bottom protection net and piled up to form a dragon mouth dike, while further ballasting and positioning the bottom protection net; the thrown filling material is a vacuum earth bag, which is self-compacted due to the pressure after stacking, and adaptively deforms with each other, thereby improving the air-tightness effect of the dike and the stacking strength, and the vacuum earth bag can be combined with the flexible bottom protection net to reliably intercept the water flow at the dragon mouth. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the bottom protection net disclosed in the present invention in a fully flat bottom protection state;

[0022] Figure 2 It is a structural schematic diagram of the bottom protection net disclosed in the present invention in the net raising state of the blocking area;

[0023] Figure 3 It is a schematic diagram of the cross-sectional structure of the dragon mouth after closing disclosed by the present invention;

[0024] Figure 4 It is a schematic diagram of the front structure of the dragon mouth after closing according to the present invention.

[0025] In the figure: 1. Bottom protection net; 11. Blocking area; 12. Bottom protection area; 2. Anchor system; 21. Outer anchor; 22. Inner anchor; 23. Ship anchor; 24. Floating drum; 3. Dike; 4. Side tensioning system; 41. Embedded piles; 42. Rope lock; 5. Upper tensioning system; 51. Embedded rod; 52. Ground anchor; 6. Vacuum earthbag. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only the best embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] A method for constructing a closure mouth of a dike, using Figure 1-Figure 4 The flexible bottom protection net 1 shown is used to intercept the thrown filler at the dragon mouth, and the thrown filler is a vacuum earth bag 6 with relatively low hardness. In order to ensure the interception performance, the bottom protection net 1 must meet the requirements of tension strength and positioning strength. Therefore, the present invention proposes a closure construction method suitable for the bottom protection net 1 to intercept, which specifically includes the following steps:

[0028] S1. According to the construction design drawings, the bottom protection net 1 is laid flat and stretched at the preset Longkou coordinates. The bottom protection net 1 is rolled up and transported to the construction site. The bottom protection net 1 is a double-layer structure, the lower layer is woven fabric, and the upper layer is high-strength dense mesh. The high-strength dense mesh is the main force-bearing skeleton. Before the net is lowered, gravity points are evenly set on the high-strength dense mesh in a square lattice pattern, such as Figure 1 As shown, the gravity point is realized by binding the vacuum earthbag 6, so that it is not only conducive to the rapid settlement and laying of the bottom protection barrier 1 and serves as the ballast of the bottom protection barrier 1, but also the gravity points distributed in the lattice can be conducive to stabilizing the thrown filling material and effectively preventing the loss of the thrown filling material; the woven cloth is in contact with the bottom of the water, which can reduce and disperse the scouring of the water flow on the bottom of the dragon mouth, and solve the problem that during the throwing and filling process at the dragon mouth, the water bottom before and after the dragon mouth is scoured to change the foundation conditions, and the thrown filling material at the dragon mouth cannot obtain effective support, resulting in the failure of closing;

[0029] The bottom protection net 1 integrates bottom protection and blocking, so if Figure 1 As shown, it includes a retaining area 11 located outside the dragon mouth and a bottom protection area 12 located inside the dragon mouth. The bottom protection area 12 is laid at the bottom of the dragon mouth, and its laying area extends a certain area from the dragon mouth area to the dike 3 areas on both sides outside and the inner filling area, which is conducive to the compaction of the bottom protection net 1 and the expansion of the bottom protection area 12. The retaining area 11 is laid at the bottom of the water discharge area outside the dragon mouth. The water discharge area is the downstream area of ​​the river or the outer sea area of ​​the sea reclamation. The width of the retaining area 11 extending outward should not be less than the height of the dike 3, so as to facilitate the blocking of the dragon mouth after folding and unfolding.

[0030] In addition, since the blocking area 11 needs to be lifted and turned upright, the distribution of gravity points in the blocking area 11 should not be too dense to reduce the difficulty and strength of lifting the net. The gravity points in the bottom protection area 12 can be arranged relatively densely, which is convenient for effectively pressing and positioning the bottom protection net 1 and stabilizing the thrown filling material;

[0031] After the bottom protection net 1 is laid, its inner and outer ends are anchored by the anchor system 2, and the anchor system 2 includes an outer anchor 21 and an inner anchor 22 which are arranged opposite to each other, and both the outer anchor 21 and the inner anchor 22 include an anchor rope, an anchor 23 and a buoy 24; wherein, the anchor rope of the inner anchor 22 tensions the inner end of the bottom protection net 1, and the woven fabric and the high-strength dense mesh of the bottom protection area 12 are connected to each other as a whole, and are tensioned by the same anchor rope, and the anchor 23 is anchored at the bottom of the reclamation area; the anchor rope of the outer anchor 21 tensions the outer end of the bottom protection net 1, and the woven fabric and the high-strength dense mesh of the retaining area 11 are separate structures, and need to be tensioned by different anchor ropes respectively, and the anchor 23 is anchored at the bottom of the water discharge area;

[0032] S2. The construction of the dikes 3 on both sides of the dragon mouth is promoted in an orderly manner. The dikes 3 on both sides of the dragon mouth are directly constructed on the bottom protection net 1, which can further ballast and fix the two side areas of the bottom protection net 1;

[0033] S3. Before the dumping and filling construction, first construct the dumping and filling area of ​​the dragon mouth, drag the anchor rope of the high-strength dense mesh through the floating drum 24, pull up the anchor 23 to unload the tension force of the blocking area 11, and use the tension system to flip the high-strength dense mesh of the blocking area 11 of the bottom protection blocking net 1 to the outer side of the dike 3. After the tension system is tightened, the dragon mouth is blocked. The blocking area 11 of the bottom protection blocking net 1 presents a blocking slope that is adapted to the dike 3. Under the gravity of the evenly distributed gravity points of the dot matrix and the tension of the tension system, the fit of the blocking slope is maintained to ensure the tension strength of each part of the blocking area 11. The blocking area 11 and the three sides of the dragon mouth are fenced to form the dragon mouth dumping and filling area;

[0034] like Figure 2-Figure 4 As shown, the tensioning system includes a side tensioning system 4 and an upper tensioning system 5; the side tensioning system 4 includes a side tensioning rope, an embedded pile 41 and a rope lock 42, the side tensioning rope is connected to the left and right side ends of the high-strength dense mesh or woven fabric of the retaining area 11, the embedded pile 41 is a branch structure, and is embedded in the embankment body during the construction of the embankment 3. According to a plurality of preset tensioning elevation positions, a plurality of connecting arms corresponding to the elevation positions are horizontally extended from the embedded pile 41, and the end of the connecting arm extends out of the outer inclined surface of the embankment 3, and is provided with a rope lock 42, which is connected to the selected side tensioning rope. A locking ring or locking pin adapted to the structure is used to lock the side pull rope after tensioning; the upper tensioning system 5 includes an upper pull rope, an embedded rod 51 and a ground anchor 52. The embedded rod 51 and the ground anchor 52 are embedded in the dike body during the construction of the dike 3. The embedded rod 51 extends out of the top of the dike 3, and a fixed pulley is rotatably arranged on the top of the dike 3. The ground anchor 52 is also located at the top of the dike 3 and is arranged at a certain distance outside the embedded rod 51. The upper pull rope is connected to the two corners of the upper edge of the high-strength dense mesh or woven fabric of the retaining area 11, and after passing through the fixed pulley, the end is locked by the ground anchor 52 to achieve the tensioning of the net body;

[0035] S4, vacuum earthbags 6 can be dumped into the dumping area from the top of the dike 3, or by ships approaching the dragon mouth, and dumped into the dike by the two-way end-to-end method, vertical blocking method, or layer-by-layer flat blocking method, until the flow is completely intercepted and the closure is achieved; because the bottom of the front and rear of the dragon mouth are tensioned and protected by woven cloth, the underwater foundation conditions near the dragon mouth are improved, and the scouring force on the bottom caused by the vertical axis vortex formed by the gradually increasing water flow or vertical blocking can be blocked and weakened by the woven cloth, and because the woven cloth spread over a certain area is an integral structure, the scouring force can be dispersed, preventing the bottom sediment near the dragon mouth from sliding, and ensuring the stability of the dike structure built by dumping and filling;

[0036] Small particles of soil are vacuum-sealed in the vacuum earthbag 6. In order to promote the plastic deformation and melting of soil particles during the self-compacting process, the moisture content of the small particles of soil should be controlled between 8% and 25%. The bag bodies of the vacuum earthbag 6 are geotextile bags, vacuum plastic bags, and high-strength cloth bags from inside to outside, which are used to protect the vacuum plastic bags inside and outside respectively and enhance the bonding strength between the vacuum earthbags 6. In addition, a certain amount of surplus is set for the three-layer bag body to facilitate adaptive deformation. The surplus of the vacuum plastic bag is the largest, the surplus of the geotextile bag is medium, and the surplus of the high-strength cloth bag is the smallest. The material source of the small particles of soil is soil with low economic added value or crushed construction waste, etc. After dumping and stacking, the atmospheric pressure, water pressure, and stacking extrusion pressure make it self-compacting, and the prefabricated blocks are adaptively deformed to each other, thereby improving the airtight effect of the Longkou dike body. After long-term accumulation, a stable overall structure is formed. At the same time, the vacuum earthbag 6 can be combined with the flexible bottom protection barrier 1 to reliably intercept the Longkou water flow;

[0037] S5. Continue to dump backfill toward the inner side of the dragon mouth to reinforce and widen the dike;

[0038] S6. In the same way as step S3, the woven fabric of the retaining area 11 of the bottom protection net 1 is turned up to the outer side of the dike 3 and tensioned through a tensioning system to form an inverted filter on the outer side of the Longkou dike, thereby weakening the scouring force of the open sea tide on the dike body. The dike can be protected before the dike 3 is constructed with a protective surface.

[0039] As a further technical solution, during the backfilling in step S4, the bottom protection area 12 is first evenly backfilled as a whole to further compress and protect the bottom protection area 12 before the closure and diversion; in addition, after the closure, the bottom protection area 12 on the inner side of the dike body is raised and backfilled to further compress and support the foot of the dike.

[0040] The directional words "up", "down", "inside", "outside", "left and right" mentioned in this article are described based on Figure 1-Figure 4These terms are mainly used to better describe the present invention and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation;

[0041] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those skilled in the art, the specific meanings of these terms in the present invention can be understood according to specific circumstances.

[0042] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a closure dam, characterized in that: The following steps are involved: 。 S1. Lay a tight bottom protection net at the bottom of the preset dragon mouth. A plurality of gravity points are fixed in a dot matrix on the bottom protection net. Gravity objects are set on the gravity points to load the bottom protection net. The bottom protection net is a double-layer structure, the lower layer is a woven cloth, and the upper layer is a high-strength dense mesh. The bottom protection net includes an outer blocking area and an inner bottom protection area. The bottom protection area is laid at the bottom of the dragon mouth, and its laying area extends from the dragon mouth area to the dike area on both sides and the inner filling area. The blocking area is laid in the water discharge area, and its width should be adapted to the height of the dike. S2, construct the dikes and weirs on both sides of the dragon mouth, and further ballast and fix the two sides of the bottom protection net; S3, the high-strength dense mesh of the blocking area of ​​the bottom protection net is turned up to the outer side of the dike and is tightened to block the dragon mouth, and the blocking area and the dragon mouth are surrounded on three sides to form a dragon mouth dumping area; S4, dumping vacuum earth bags into the dumping area to occupy the dike until the flow is completely cut off and the joint is closed; S5. Continue to dump backfill toward the inner side of the dragon mouth to reinforce and widen the dike; S6. Turn the woven fabric of the retaining area of ​​the bottom protection net up to the outer side of the dike, and tighten it to form the inverted filter of the Longkou dike.

2. The closure construction method of the intercepting dike according to claim 1, characterized in that: After the bottom protection net in step S1 is laid flat, it is tensioned by an anchor system, and the anchor system includes an outer anchor and an inner anchor arranged opposite to each other. The inner anchor tensions the inner end of the bottom protection net, and the outer anchor tensions the woven fabric of the bottom protection net and the outer ends of the high-strength dense mesh net respectively. Floating drums are arranged on the outer anchors to facilitate the anchoring and deployment of the high-strength dense mesh net and woven fabric in the retaining area.

3. The closure construction method of the intercepting dike according to claim 2, characterized in that: The retaining area of ​​the bottom protection net in steps S3 and S6 is tensioned by a side tensioning system and an upper tensioning system, the side tensioning system tensions the left and right side ends of the retaining area, and the upper tensioning system tensions the upper end of the retaining area, the side tensioning system comprises side pull ropes, embedded piles and rope locks, the embedded piles are embedded in the dike construction in step S2, connecting arms are respectively arranged on the embedded piles at a plurality of preset elevations, the connecting arms extend to the outer side surface of the dike and are provided with rope locks, the side pull ropes are locked by the rope locks after tensioning, the upper tensioning system comprises upper pull ropes, embedded rods and ground anchors, the embedded rods and the ground anchors are both embedded in the dike construction in step S2, the embedded rods extend out from the top of the dike, a fixed pulley is rotatably arranged on the top of the embedded rods, the upper pull ropes are connected to the two corners of the upper edge of the retaining area, the upper pull ropes are wound around the fixed pulley, and tension is achieved by locking the ends of the ground anchors.

4. The closure construction method of a dam according to any one of claims 1 to 3, characterized in that: The gravity object is the vacuum earth bag tied to the high-strength dense mesh.

5. The closure construction method of the intercepting dike according to claim 4, characterized in that: The distribution of gravity points in the bottom protection area is denser than that in the retaining area. When filling in step S4, the bottom protection area is firstly filled evenly as a whole. Before the closure and diversion, the bottom protection area is further compressed and protected. After the closure, the bottom protection area inside the dike body is raised and filled to further compress and support the foot of the dike.

6. The closure construction method of the intercepting dike according to claim 5, characterized in that: Small soil particles are vacuum-sealed in the vacuum soil bag, and the bag body is composed of a geotextile bag, a vacuum plastic bag, and a high-strength cloth bag from the inside to the outside.

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