Prefabricated cofferdams for soft soil foundations

Abstract

This utility model provides a prefabricated cofferdam for soft soil foundations, relating to water conservancy engineering and cofferdam technology. The prefabricated cofferdam includes multiple cofferdam units arranged and connected sequentially along a first direction. Each cofferdam unit includes a first water-retaining component, a second water-retaining component, and water-retaining filler. The first water-retaining component is vertically inserted into the foundation, with its first side serving as the construction area. The second water-retaining component includes a horizontal portion and a vertical portion. The horizontal portion is located on the second side of the first water-retaining component, laid on the foundation surface, and abuts against the first water-retaining component. The vertical portion extends upwards from the horizontal portion beyond the water surface, enclosing a receiving space together with the horizontal portion and the first water-retaining component. The water-retaining filler fills the receiving space, effectively preventing water from seeping into the construction area.

Description

Technical Field

[0001] This utility model relates to the field of water conservancy engineering and cofferdam technology, and more specifically, to a prefabricated cofferdam for soft soil foundation. Background Technology

[0002] Soft soil, with its high water content, low bearing capacity, and significant compressibility, presents severe challenges to engineering construction. Traditional treatment methods, such as surcharge preloading and cement mixing piles, can improve foundation performance, but they suffer from long construction periods, significant disturbance, and high costs. Especially in projects near water bodies, fluctuations in groundwater levels and soil rheological properties can easily lead to slope instability and uneven settlement, seriously affecting the safety of subsequent structures. Therefore, there is an urgent need to develop efficient and environmentally friendly foundation treatment technologies, and to optimize them in conjunction with temporary support structures, to meet the construction requirements under complex geological conditions.

[0003] A cofferdam is a temporary water-retaining structure used in hydraulic engineering, bridge construction, and underground projects. Its primary purpose is to create a dry construction environment and prevent water flow or groundwater from interfering with operations. Traditional cofferdams often employ sheet piles, earth-rock cofferdams, or cast-in-place concrete structures. While they possess a certain water-retaining capacity, they frequently face problems such as long construction periods, insufficient structural stability, and material waste in complex geological conditions (e.g., soft soil foundations) or narrow construction sites. For example, sheet pile cofferdams are prone to leakage at the interlocks in soft soil due to soil deformation, while cast-in-place concrete cofferdams require a long curing time, making them difficult to meet the demands of rapid construction.

[0004] Compared to traditional cofferdams, prefabricated cofferdams achieve rapid construction and dismantling through modular assembly, offering advantages such as high construction efficiency, reusability, and strong adaptability. They are particularly suitable for projects with tight schedules or stringent environmental requirements. For example, the widely used double-layer steel sheet pile cofferdam structure boasts excellent stability and water-retaining performance. However, it still cannot effectively address the issues of foundation pressure diffusion and low bearing capacity in deep soft soil foundation construction conditions. Therefore, how to improve existing prefabricated cofferdam structures to better suit soft soil foundation construction conditions has become an urgent technical problem to be solved. Utility Model Content

[0005] In view of this, the present invention provides a prefabricated cofferdam for soft soil foundation, which can increase the contact area with the foundation and reduce the impact of foundation settlement while maintaining the stability of the cofferdam.

[0006] An exemplary embodiment of this utility model provides a prefabricated cofferdam for soft soil foundation, comprising a plurality of cofferdam units arranged along a first direction and connected sequentially. Each cofferdam unit includes: a first water-retaining member, inserted vertically into the foundation, with a first side of the first water-retaining member serving as a construction area; a second water-retaining member, comprising: a horizontal portion located on the second side of the first water-retaining member, the horizontal portion being laid on the foundation surface and abutting against the first water-retaining member; a vertical portion extending upward from the horizontal portion beyond the water surface, and enclosing a receiving space with the horizontal portion and the first water-retaining member; and water-retaining filler, filling the receiving space, suitable for preventing water from seeping into the construction area.

[0007] According to an embodiment of the present invention, the aforementioned cofferdam unit further includes a support rod extending along a second direction perpendicular to the first direction. The support rod is disposed between the first water-blocking member and the vertical portion, and is suitable for maintaining the first water-blocking member and the vertical portion parallel to each other.

[0008] According to an embodiment of the present invention, at least two support rods are provided, arranged in parallel at intervals along the first direction.

[0009] According to an embodiment of the present invention, the height of the water-blocking filler is greater than or equal to the water surface height.

[0010] According to an embodiment of the present invention, the width of the horizontal portion in the second direction is greater than the distance between the vertical portion and the first water-blocking member.

[0011] According to an embodiment of the present invention, the aforementioned cofferdam unit includes: a starting end unit; an ending end unit disposed on one side of the starting end unit along a first direction; and an intermediate unit group disposed between the starting end unit and the ending end unit.

[0012] According to an embodiment of the present invention, the above-mentioned intermediate monomer group includes a plurality of intermediate monomers connected sequentially along a first direction.

[0013] According to an embodiment of the present invention, a first folded portion is formed on the starting end unit, and the projection of the first folded portion in the vertical direction is located within the coverage area of ​​the horizontal portion of the starting end unit; a left folded portion is formed on the intermediate unit to cooperate with the first folded portion, and the projection of the left folded portion in the vertical direction is located outside the coverage area of ​​the horizontal portion of the intermediate unit.

[0014] According to an embodiment of the present invention, a second folded portion is formed on the aforementioned end unit, and the projection of the second folded portion in the vertical direction is located outside the coverage area of ​​the horizontal portion of the aforementioned end unit; a right folded portion that cooperates with the aforementioned second folded portion is also formed on the aforementioned middle unit, and the projection of the aforementioned right folded portion in the vertical direction is located within the coverage area of ​​the horizontal portion of the aforementioned middle unit; adjacent aforementioned middle units are connected by the cooperation of the aforementioned left folded portion and the aforementioned right folded portion.

[0015] According to an embodiment of the present invention, the cross-sections of the first folded portion, the left folded portion, the right folded portion, and the second folded portion are constructed as a spiral shape.

[0016] The prefabricated cofferdam for soft soil foundations provided by this invention features a first water-retaining component that is directly inserted into the foundation, ensuring stability and reliability. The second water-retaining component, secured by the downward pressure of the water-retaining filler and the lateral force balanced between the filler and water in the horizontal direction, is stably placed on the foundation surface. This design prevents the entire cofferdam from tilting horizontally. Furthermore, because the horizontal section is laid on the foundation surface and adheres tightly to the foundation under the action of the water-retaining filler, the contact area between the cofferdam and the foundation is significantly increased compared to traditional insertion-type installations, avoiding uneven settlement caused by concentrated pressure in soft soil foundations. In addition, since the second water-retaining component does not need to be inserted into the foundation, construction complexity is reduced, and the impact of construction noise on the surrounding environment is minimized. Attached Figure Description

[0017] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the present invention with reference to the accompanying drawings, in which:

[0018] Figure 1 This is a three-dimensional schematic diagram of a single cofferdam provided in an exemplary embodiment of this utility model;

[0019] Figure 2 This is a side view of a single cofferdam provided in an exemplary embodiment of the present invention;

[0020] Figure 3 This is a top view of a single cofferdam provided in an exemplary embodiment of this utility model;

[0021] Figure 4 This is a top view of a prefabricated cofferdam for soft soil foundation provided by an exemplary embodiment of the present invention.

[0022] In the accompanying drawings, the meanings of the reference numerals are as follows:

[0023] 1. Individual cofferdam;

[0024] 11. First water-blocking component;

[0025] 12. Second water-blocking component;

[0026] 121. Horizontal section;

[0027] 122. Vertical part;

[0028] 13. Water-retaining filler;

[0029] 14. Support rod;

[0030] 2. Initial monomer;

[0031] 21. First fold-over section;

[0032] 3. Terminal monomer;

[0033] 31. Second fold section;

[0034] 4. Intermediate monomers;

[0035] 41. Left fold;

[0036] 42. Right fold. Detailed Implementation

[0037] The embodiments of the present invention will now be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the following detailed description, numerous specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the present invention.

[0038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0039] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0040] When using expressions such as "at least one of A, B and C", they should generally be interpreted in accordance with the meaning that is commonly understood by those skilled in the art (e.g., "a system having at least one of A, B and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B and C, etc.).

[0041] Figure 1 This is a three-dimensional schematic diagram of a single cofferdam provided in an exemplary embodiment of this utility model. Figure 2 This is a side view of a single cofferdam unit provided in an exemplary embodiment of the present invention. Figure 3 This is a top view of a single cofferdam provided in an exemplary embodiment of the present invention.

[0042] An exemplary embodiment of this utility model provides a prefabricated cofferdam for soft soil foundations, such as... Figures 1-3 As shown, the cofferdam includes multiple individual cofferdam units 1 arranged and connected sequentially along a first direction. Each cofferdam unit 1 includes a first water-retaining component 11, a second water-retaining component 12, and water-retaining filler 13. The first water-retaining component 11 is vertically inserted into the foundation, with its first side serving as the construction area. The second water-retaining component 12 includes a horizontal portion 121 and a vertical portion 122. The horizontal portion 121 is located on the second side of the first water-retaining component 11, laid on the foundation surface, and abuts against the first water-retaining component 11. The vertical portion 122 extends upward from the horizontal portion 121 beyond the water surface, enclosing a receiving space together with the horizontal portion 121 and the first water-retaining component 11. The water-retaining filler 13 fills the receiving space, effectively preventing water from seeping into the construction area.

[0043] In this implementation, the first water-retaining component 11 is directly inserted into the foundation, ensuring stability and reliability. The second water-retaining component 12, aided by the downward pressure of the water-retaining filler 13 and the lateral forces balanced between the filler 13 and the water in the horizontal direction, is stably placed on the foundation surface. This makes the entire cofferdam unit horizontally stable and less prone to collapse. Simultaneously, since the horizontal section 121 is laid on the foundation surface and adheres tightly to the foundation under the action of the water-retaining filler 13, the contact area between the entire cofferdam unit 1 and the foundation is increased, avoiding uneven settlement caused by pressure concentration in soft soil. Furthermore, since the second water-retaining component 12 does not need to be inserted into the foundation, construction difficulty is reduced, and the impact of construction noise on the surrounding environment is minimized.

[0044] For example, such as Figure 2 As shown, the first water-retaining component 11 is a steel sheet pile, also known as an inner layer steel sheet pile. Figure 2In the middle, the right side of the first water-retaining component 11 is the construction area. The second water-retaining component 12 is composed of a horizontal part 121 and a vertical part 122. For example, the vertical steel plate and the bottom steel plate are connected by welding. Between the vertical steel plate, the bottom steel plate and the inner steel sheet pile is a space for filling the water-retaining filler 13. Taking the cofferdam unit 1 as an example, this space is an open cubic space. When multiple cofferdam units 1 are arranged along the first direction, the multiple cubic spaces are interconnected to form a long strip space extending along the first direction. The two ends of the long strip space are sealed by natural walls or artificial walls on the construction site.

[0045] In one exemplary embodiment, such as Figure 1 and Figure 2 As shown, the cofferdam unit 1 also includes a support rod 14 extending along a second direction perpendicular to the first direction. The support rod 14 is disposed between the first water-blocking member 11 and the vertical part 122, and is suitable for maintaining the first water-blocking member 11 and the vertical part 122 parallel to each other.

[0046] In this embodiment, the first water-blocking member 11 and the vertical part 122 are kept parallel mainly by the lateral force balanced between the water-blocking packing 13 and the water, as well as the downward pressure of the water-blocking packing 13. The support rod 14 plays an auxiliary role in maintaining their parallelism. In other words, the support rod 14 can prevent the second water-blocking member 12 from tilting or translating.

[0047] Reference Figure 1 As shown, Figure 1 The x-direction in the figure is the first direction in the embodiment, the y-direction in the figure is the second direction in the embodiment, and the z-direction in the figure is the vertical direction in the embodiment.

[0048] For example, the two ends of the support rod 14 are fixedly connected to the vertical part 122 and the first water-blocking member 11, respectively, and the connection method includes but is not limited to bolt connection.

[0049] More specifically, after determining the dimensions of the first water-blocking component 11, the horizontal part 121, and the vertical part 122, during assembly, the horizontal part 121 and the vertical part 122 are first welded together. Then, the first water-blocking component 11 is driven into the foundation, and the welded second water-blocking component 12 is placed. For shallower water areas, it can be manually arranged; for deeper water areas, it is hoisted to the designated location by hoisting equipment. When placing the second water-blocking component 12, its horizontal part 121 only needs to touch or partially abut against the first water-blocking component 11, mainly because the side of the first water-blocking component 11 is not completely flat. Then, all or part of the water in the enclosed space is pumped out, and water-blocking filler 13 is filled in. After the second water-blocking component 12 is stable and reliable, the support rod 14 is installed, and finally, water-blocking filler is added according to the water depth.

[0050] Reference Figure 2As shown, the wavy line on the left side of the vertical part 122 represents the water area, the water-blocking filler 13 is between the vertical part 122 and the first water-blocking component 11, and the construction area is to the right of the first water-blocking component 11.

[0051] According to embodiments of this disclosure, such as Figure 1 and Figure 3 As shown, at least two support rods 14 are provided, which are arranged in parallel at intervals along the first direction.

[0052] In such an implementation, the number of support rods 14 is preferably two or three, and they are preferably made of steel to provide sufficient support rigidity.

[0053] In one exemplary embodiment, such as Figure 2 As shown, the height of the water-retaining filler 13 is greater than or equal to the water surface height.

[0054] In this implementation, since multiple cofferdam units are assembled sequentially along the first direction, there will be slow seepage at the assembly point. By adding water-blocking filler 13 to be level with or higher than the water surface, the seepage at this point is blocked, thereby improving the water-blocking effect.

[0055] Reference Figure 2 As shown, the height h of the water-retaining filler 13 is greater than the water surface height.

[0056] For example, the water-retaining filler 13 is preferably gravelly soil or flexible bagged soil.

[0057] In some other embodiments, sealing measures such as sealing strips may be added to the assembly structure to provide waterproofing.

[0058] In one exemplary embodiment, such as Figure 2 As shown, the width of the horizontal portion 121 in the second direction is greater than the distance between the vertical portion 122 and the first water-blocking member 11.

[0059] In this embodiment, the width of the horizontal portion 121 in the second direction is greater than the distance between the vertical portion 122 and the first water-blocking member 11, that is... Figure 2 As shown, one end of the horizontal part 121 in the second direction abuts against the first water-blocking member 11, while the other end extends out of the vertical part 122. The extended part can further increase the contact area with the foundation, reduce the impact of soft soil foundation subsidence on the cofferdam, and at the same time, the extended part can also further improve the stability of the second water-blocking member 12 with the help of water pressure.

[0060] Specifically, in Figure 2 In the middle, the distance between the vertical part 122 and the first water-stopping part 11 is a. The size of a is mainly determined by the water depth. When the water is deeper, a is usually larger to have better water-proof performance.

[0061] Figure 4 This is a top view of a prefabricated cofferdam for soft soil foundation provided by an exemplary embodiment of the present invention.

[0062] In one exemplary embodiment, such as Figure 4 As shown, the cofferdam unit 1 includes a starting unit 2, an ending unit 3, and an intermediate unit group. The ending unit 3 is arranged along a first direction on one side of the starting unit 2, and the intermediate unit group is located between the starting unit 2 and the ending unit 3.

[0063] In this implementation, the starting unit 2, the intermediate unit group and the ending unit 3 are connected sequentially along the first direction to form a prefabricated cofferdam to block water flow in the construction area.

[0064] According to embodiments of this disclosure, such as Figure 4 As shown, the intermediate monomer group includes multiple intermediate monomers 4 connected sequentially along the first direction.

[0065] In this implementation, multiple intermediate monomers 4 are connected sequentially along the first direction, and the two intermediate monomers 4 located at the beginning and end are also connected to the starting monomer 2 and the ending monomer 3, respectively.

[0066] Further according to embodiments of this disclosure, such as Figure 4 As shown, a first folded portion 21 is formed on the starting end unit 2, and the projection of the first folded portion 21 in the vertical direction is located within the coverage area of ​​the horizontal portion 121 of the starting end unit 2. A left folded portion 41 is formed on the middle unit 4 to cooperate with the first folded portion 21, and the projection of the left folded portion 41 in the vertical direction is located outside the coverage area of ​​the horizontal portion 121 of the middle unit 4.

[0067] In this embodiment, during assembly, taking the initial unit 2 as an example, the left folded part 41 of the middle unit 4 is aligned with the first folded part 21 in the vertical direction and then inserted and fitted from top to bottom. The fitting position is within the range of the initial unit 2, that is, the left folded part 41 of the middle unit 4 extends out of the middle unit 4 and is inserted and fitted with the first folded part 21 of the initial unit 2.

[0068] Further according to embodiments of this disclosure, such as Figure 4 As shown, a second folded portion 31 is formed on the end unit 3, and the projection of the second folded portion 31 in the vertical direction is outside the coverage area of ​​the horizontal portion 121 of the end unit 3. A right folded portion 42 is also formed on the middle unit 4, which cooperates with the second folded portion 31, and the projection of the right folded portion 42 in the vertical direction is within the coverage area of ​​the horizontal portion 121 of the middle unit 4. Adjacent middle units 4 are connected by the cooperation of the left folded portion 41 and the right folded portion 42.

[0069] In this embodiment, after the middle unit 4 at the head is connected to the starting unit 2, multiple adjacent middle units 4 are connected by left folding portions 41 and right folding portions 42. For example, the right folding portion of the middle unit 4 at the head is vertically aligned with the left folding portion of the second middle unit 4, and then inserted from top to bottom. The insertion position is within the range of the middle unit 4 at the head. That is, between two adjacent middle units 4, the left folding portion 41 and the right folding portion 42 are inserted within the range of the previous middle unit 4, and so on up to the middle unit 4 at the tail. After the second folding portion 31 of the ending unit 3 is vertically aligned with the right folding portion 42 of the middle unit 4 at the tail, it is inserted from top to bottom. The insertion position is within the range of the middle unit 4 at the tail. The second folding portion 31 of the ending unit 3 extends out of the ending unit 3 and inserts with the right folding portion of the middle unit 4 at the tail.

[0070] In one exemplary embodiment, such as Figure 4 As shown, the cross-sections of the first folding portion 21, the left folding portion 41, the right folding portion 42, and the second folding portion 31 are constructed as a spiral shape.

[0071] In this implementation, the helical cross-section of the folded portion helps improve the stability of the connection, while also extending the seepage path and enhancing the water-blocking performance.

[0072] More specifically, two first folding portions 21 are provided, respectively formed on the first water-blocking member 11 and the vertical portion 122 of the starting end unit 2. Two left folding portions 41 and two right folding portions 42 are each provided, respectively formed on the first water-blocking member 11 and the vertical portion 122 of the middle unit 4. Two second folding portions 31 are also provided, respectively formed on the first water-blocking member 11 and the vertical portion 122 of the ending end unit 3.

[0073] In some alternative embodiments, such as Figure 2 and Figure 4 As shown, the length of the cofferdam unit 1 is b, and the width of the cofferdam unit 1 is a (i.e., the distance between the vertical part 122 and the first water-retaining component 11 in the above embodiment), both determined according to the water head. For example, for a water level greater than 5m, it is preferable that a is greater than 1 meter and b is less than 0.5 meters. In some other embodiments, since the second water-retaining component 12 does not need to be inserted into the foundation, the length b of the cofferdam unit 1 can be appropriately increased, which can reduce the number of construction operations.

[0074] In some other embodiments, the first folding part 21, the left folding part 41, the right folding part 42, and the second folding part 31 can also be connected by a method other than plugging. For example, the first folding part 21, the left folding part 41, the right folding part 42, and the second folding part 31 can be made of thinner steel plates with a certain deformation capability. After the starting end unit 2, the middle unit 4, and the ending end unit 3 are roughly arranged, they are manually folded to connect them.

[0075] Those skilled in the art will understand that the features described in the various embodiments of this utility model can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in this utility model. In particular, the features described in the various embodiments of this utility model can be combined and / or combined in various ways without departing from the spirit and teachings of this utility model. All such combinations and / or combinations fall within the scope of this utility model.

[0076] The embodiments of this utility model have been described above. However, these embodiments are merely illustrative and not intended to limit the scope of this utility model. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of this utility model, those skilled in the art can make various substitutions and modifications, all of which should fall within the scope of this utility model.

Claims

1. A fabricated cofferdam for soft ground foundation, characterized by, It includes multiple individual cofferdams arranged along a first direction and connected sequentially, wherein each cofferdam individual includes: The first water-retaining component is inserted vertically into the foundation, and the first side of the first water-retaining component is used as the construction area; The second water-blocking component includes: A horizontal section is located on the second side of the first water-blocking member, and the horizontal section is laid on the foundation surface and abuts against the first water-blocking member; The vertical portion extends upward from the horizontal portion beyond the water surface, and together with the horizontal portion and the first water-blocking member, encloses a receiving space. Water-retaining filler, which is used to fill the containment space, is suitable for preventing water from seeping into the construction area.

2. The fabricated cofferdam for soft ground according to claim 1, wherein, The cofferdam unit also includes a support rod extending along a second direction perpendicular to the first direction. The support rod is disposed between the first water-blocking member and the vertical part, and is adapted to maintain the first water-blocking member and the vertical part parallel to each other.

3. The fabricated cofferdam for soft ground according to claim 2, wherein, The support rods are provided in at least two form, arranged in parallel at intervals along the first direction.

4. The fabricated cofferdam for soft ground according to claim 1, wherein The height of the water-retaining filler is greater than or equal to the water surface height.

5. The fabricated cofferdam for soft ground according to claim 1, wherein The width of the horizontal portion in the second direction is greater than the distance between the vertical portion and the first water-blocking member.

6. The prefabricated cofferdam for soft soil foundation according to any one of claims 1-5, characterized in that, The individual cofferdam units include: Starting point monomer; The end unit is disposed on one side of the beginning unit along the first direction; An intermediate monomer group is disposed between the starting end monomer and the ending end monomer.

7. The prefabricated cofferdam for soft soil foundation according to claim 6, characterized in that, The intermediate monomer group includes a plurality of intermediate monomers connected sequentially along a first direction.

8. The prefabricated cofferdam for soft soil foundation according to claim 7, characterized in that, A first folded portion is formed on the starting end unit, and the projection of the first folded portion in the vertical direction is located within the coverage area of ​​the horizontal portion of the starting end unit; The intermediate unit has a left fold portion that cooperates with the first fold portion, and the projection of the left fold portion in the vertical direction is outside the coverage area of ​​the horizontal portion of the intermediate unit.

9. The prefabricated cofferdam for soft soil foundation according to claim 8, characterized in that, A second folded portion is formed on the end unit, and the projection of the second folded portion in the vertical direction is outside the coverage area of ​​the horizontal portion of the end unit; The intermediate unit also has a right folding portion that cooperates with the second folding portion, and the projection of the right folding portion in the vertical direction is located within the coverage area of ​​the horizontal portion of the intermediate unit; The adjacent intermediate units are connected by the left fold and the right fold.

10. The prefabricated cofferdam for soft soil foundation according to claim 9, characterized in that, The cross-sections of the first fold, the left fold, the right fold, and the second fold are constructed as a spiral shape.

Images