Combined cofferdam

Abstract

The invention discloses a combined cofferdam in the technical field of hydraulic engineering construction. The combined cofferdam comprises an upstream steel film end sealing cofferdam located on the upstream of a river channel and a downstream steel film end sealing cofferdam located on the downstream of the river channel. The diversion channel comprises a base formed by compaction treatment of original soil and local stones, double-row piles located on the side portion of the base, bamboo plywood laid on the surface layer of the double-row piles and the surface layer of the base and impermeable membrane cloth. A stilling pool is arranged in a downstream outlet area of the diversion channel; the ton bags are arranged at the bottom folding points and lap joints of the bamboo plywood and the impermeable membrane cloth and the downstream sides of the upstream steel membrane end sealing cofferdam and the downstream steel membrane end sealing cofferdam; through a brand new structural design, a combined cofferdam structural form is constructed, so that the safety and stability of the combined cofferdam under the conditions of large flow velocity and flow, large upstream and downstream height difference, special ground conditions and unfavorable geological conditions are remarkably improved.

Description

Technical Field

[0001] The invention relates to the technical field of water conservancy project construction, in particular to a combined cofferdam. Background Art

[0002] In the construction of water conservancy projects, the safety and stability of cofferdams as temporary water retaining structures are of vital importance. Conventional cofferdams often expose many problems when faced with high flow velocity and flow, large elevation difference between upstream and downstream, special terrain and adverse geological conditions. For example, in high flow velocity and large flow environment, cofferdams are prone to severe scouring, resulting in structural damage; in special geological areas, such as soft soil foundations, the stability of cofferdams is difficult to guarantee, and settlement and slippage are prone to occur; in addition, seepage problems under adverse geological conditions also seriously affect the normal use of cofferdams, increasing construction risks and costs.

[0003] Therefore, there is an urgent need to develop a new, efficient, stable cofferdam structure that can adapt to complex conditions. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of the present invention to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] Therefore, the purpose of the present invention is to provide a combined cofferdam, which, through a new structural design, constructs a combined cofferdam structure to significantly improve its safety and stability under high flow rate, large upstream and downstream height difference, special terrain and adverse geological conditions.

[0006] In order to solve the above technical problems, the present invention provides a combined cofferdam, which adopts the following technical scheme: comprising: an upstream steel membrane sealed cofferdam located upstream of the river channel, and a downstream steel membrane sealed cofferdam located downstream of the river channel; a diversion channel, comprising a base formed by compaction of original soil and partial stones, double rows of piles located on the side of the base, and bamboo plywood and anti-seepage membrane cloth laid on the surface layer of the double rows of piles and the surface layer of the base; an energy dissipation pool is arranged in the downstream outlet area of ​​the diversion channel; and ton bags are arranged at the bottom inflection points and overlaps of the bamboo plywood and the anti-seepage membrane cloth and on the backwater side of the upstream steel membrane sealed cofferdam and the downstream steel membrane sealed cofferdam.

[0007] Optionally, the height of the upstream steel membrane end sealing cofferdam is 4.5m, and the height of the downstream steel membrane end sealing cofferdam is 3.5m.

[0008] Optionally, the diversion channel also includes a concrete base plate and a concrete retaining wall. The concrete base plate is arranged above the bamboo plywood and the anti-seepage membrane cloth, and the concrete retaining wall is arranged on both sides of the concrete base plate. The double-row pile surface layer and the concrete retaining wall are paved with the bamboo plywood and the anti-seepage membrane cloth.

[0009] Optionally, the double-row piles include a single-row steel pipe piles located on one side of the concrete retaining wall and a double-row steel pipe piles located on the other side of the concrete retaining wall. The double-row steel pipe piles are connected as a whole by frame pipes, and the surface layers of the single-row steel pipe piles and the double-row steel pipe piles are paved with the bamboo plywood and anti-seepage membrane cloth.

[0010] Optionally, the middle of the double-row steel pipe piles and the back sides of the single-row steel pipe piles are filled with earth bags, and the earth bags filled in the middle of the double-row steel pipe piles are exposed for 4.5 m.

[0011] Optionally, the concrete base plate is cast in situ using C30 commercial concrete and has a thickness of 300 mm. The concrete retaining wall is equipped with φ14 steel bars with a width of 500 mm and a height of 1200 mm.

[0012] Optionally, a plurality of groups of steel sheet piles are provided in the downstream outlet area of ​​the diversion channel, and the energy dissipation pool is provided between the plurality of groups of steel sheet piles.

[0013] Optionally, cement bags are also included, and multiple cement bags are hung on the single-row steel pipe piles and the double-row steel pipe piles, and the multiple cement bags are pressed on the surface of the bamboo plywood and the anti-seepage membrane cloth.

[0014] Optionally, the upstream steel membrane end-sealed cofferdam and the downstream steel membrane end-sealed cofferdam are both made of channel steel trusses, and are connected and fixed by φ48 steel pipes and φ160mm round timbers to form a whole.

[0015] Optionally, the front side of the channel steel truss is paved with bamboo plywood and anti-seepage membrane cloth, and a plurality of sand bags are hung on the channel steel truss, and the plurality of sand bags are pressed on the surface of the bamboo plywood and the anti-seepage membrane cloth.

[0016] In summary, the present invention includes at least one of the following beneficial effects:

[0017] 1. The present invention forms a multi-layer anti-seepage system by laying bamboo plywood and anti-seepage membrane cloth, combined with filling earth bags on both sides of the cofferdam, which effectively prevents leakage of groundwater and cofferdam during flow, effectively prevents water exchange inside and outside the cofferdam, creates dry slot operation conditions, ensures the construction environment, and improves construction quality.

[0018] 2. The concrete bottom plate and concrete retaining wall designed by the present invention enhance the bearing capacity and deformation resistance of the cofferdam foundation, improve the harm caused by unfavorable geology, slow down the seepage rate, and greatly enhance the stability of the cofferdam structure;

[0019] 3. The present invention sets a steel sheet pile energy dissipation pool downstream. By utilizing the special structure of the energy dissipation pool, it effectively reduces the scouring damage of the water flow to the cofferdam and the existing river channel when the upstream and downstream height difference is large and the flow rate is high. The energy dissipation pool can make the high-speed water flow turbulent in the pool, consume the water flow energy, slow down the impact force of the water flow into the river channel, and play a significant role in energy dissipation and anti-scouring;

[0020] 4. The combined cofferdam structure of the present invention is stable, has strong anti-seepage performance, strong flow capacity, strong stability, increases construction space, creates dry slot working conditions, effectively promotes engineering construction, promotes the progress of cofferdam technology in the water conservancy engineering industry, ensures the overall construction environment and construction quality, and at the same time realizes the reasonable allocation of river water resources during construction.

[0021] 5. The present invention is applicable to large and medium-sized river management, bridge and lock repair and construction, and construction projects with tight construction schedules that have strict environmental protection requirements, sand layer geology, large upstream and downstream elevation differences, the presence of phreatic layers and seepage effects, and can improve the stability of the cofferdam base, comprehensively enhance the cofferdam's flow capacity and construction safety, and has broad application prospects and high social and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the plane structure of the present invention;

[0024] Figure 2 For the present invention Figure 1 A schematic cross-sectional structural diagram of ;

[0025] Figure 3 It is a schematic diagram of the cross-sectional structure of the energy dissipation pool of the present invention;

[0026] Figure 4 It is a schematic diagram of the cross-sectional structure of the upstream steel membrane sealed cofferdam and the downstream steel membrane sealed cofferdam of the present invention.

[0027] Explanation of the reference numerals: 1. Upstream steel membrane sealed cofferdam; 2. Double row of piles; 3. Concrete base plate; 4. Concrete retaining wall; 5. Energy dissipation pool; 6. Downstream steel membrane sealed cofferdam; 7. Ton bags; 8. Bamboo plywood and anti-seepage membrane cloth; 9. Base; 10. Earth bags; 11. Cement bags; 12. Steel sheet piles; 13. Channel steel trusses; 14. Steel pipes; 15. Round timber; 16. Sand bags; 17. Rack pipes. DETAILED DESCRIPTION

[0028] The following will combine 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 part of the embodiments of the present invention, not all the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Embodiment 1

[0032] Reference Figure 1-Figure 4 The present invention discloses a combined cofferdam, comprising: an upstream steel film sealed cofferdam 1 located upstream of a river channel, and a downstream steel film sealed cofferdam 6 located downstream of the river channel; the height of the upstream steel film sealed cofferdam 1 is 4.5m, and the height of the downstream steel film sealed cofferdam 6 is 3.5m.

[0033] The upstream steel membrane sealed cofferdam 1 and the downstream steel membrane sealed cofferdam 6 are both formed by welding a plurality of channel steels into a channel steel truss 13, and are connected and fixed by φ48 steel pipes 14 and φ160mm logs 15 to form a whole.

[0034] The front side of the channel steel truss 13 is paved with bamboo plywood and anti-seepage membrane cloth 8, and a plurality of sand bags 16 are hung on the channel steel truss 13. The plurality of sand bags 16 are pressed on the surface of the bamboo plywood and the anti-seepage membrane cloth 8. The bamboo plywood and the anti-seepage membrane cloth 8 are used to reduce leakage during flow through the cofferdam, thereby creating conditions for a dry channel operation site; they effectively slow down the seepage speed and ensure the construction working environment. Similarly, the bamboo plywood and anti-seepage membrane cloth 8 mentioned below have the same effect.

[0035] The diversion channel includes a base 9 formed by compacting the original soil and local stones. The diversion channel is hardened, which effectively improves the harm caused by the bad geology and greatly improves the structural stability and flow stability of the diversion channel; the double-row piles 2 located on the side of the base 9, the bamboo plywood and anti-seepage membrane cloth 8 laid on the surface layer of the double-row piles 2 and the surface layer of the base;

[0036] The channel steel truss 13 and the double-row pile 2 structure greatly increase the flow capacity of the cofferdam, and ensure the flow safety when there may be large water level changes before and after the flood season.

[0037] The diversion channel also includes a concrete bottom plate 3 and a concrete retaining wall 4. The concrete bottom plate 3 is arranged above the bamboo plywood and the anti-seepage membrane 8. The concrete retaining wall 4 is arranged on both sides of the concrete bottom plate 3. The arrangement of the concrete bottom plate 3 and the concrete retaining wall 4 enhances the bearing capacity and anti-deformation capacity of the cofferdam foundation, improves the harm caused by poor geology, slows down the seepage rate, and greatly enhances the stability of the cofferdam structure. The surface layer of the double-row piles 2 and the concrete retaining wall 4 are paved with bamboo plywood and anti-seepage membrane 8.

[0038] In detail, in this embodiment, the concrete base plate 3 is cast in situ using C30 commercial concrete with a thickness of 300 mm, and the concrete retaining wall 4 is equipped with φ14 steel bars with a width of 500 mm and a height of 1200 mm.

[0039] In detail, in this embodiment, the double-row piles 2 include a single-row steel pipe pile on one side of the concrete retaining wall 4 and a double-row steel pipe pile on the other side of the concrete retaining wall 4. The double-row steel pipe piles are connected as a whole by a rack pipe 17. The surface layers of the single-row steel pipe piles and the double-row steel pipe piles are paved with bamboo plywood and anti-seepage membrane cloth 8.

[0040] In detail, in the present embodiment, the middle of the double-row steel pipe piles and the back of the single-row steel pipe piles are filled with earthbags 10, wherein the earthbags 10 are made of existing soil, and the earthbags 10 filled in the middle of the double-row steel pipe piles are exposed 4.5m; by laying bamboo plywood and anti-seepage membrane cloth 8, combined with filling earthbags 10 on both sides of the cofferdam, a multi-layer anti-seepage system is formed, which effectively prevents leakage of groundwater and cofferdam during flow, effectively prevents water exchange inside and outside the cofferdam, creates dry trench operation conditions, ensures the construction environment, and improves construction quality.

[0041] It also includes cement bags 11. Multiple cement bags 11 are hung on the single-row steel pipe piles and the double-row steel pipe piles. Multiple cement bags 11 are pressed on the surface of the bamboo plywood and the anti-seepage membrane cloth 8 to increase the weight and resist the lateral water pressure.

[0042] A plurality of groups of steel sheet piles 12 are arranged in the downstream outlet area of ​​the diversion channel, and the energy dissipation pool 5 is arranged between the plurality of groups of steel sheet piles 12. The special structure of the energy dissipation pool effectively reduces the scouring damage of the water flow to the cofferdam and the existing river channel when the upstream and downstream height difference is large and the flow rate is large. The energy dissipation pool can make the high-speed water flow turbulent in the pool, consume the water flow energy, slow down the impact force of the water flow entering the river channel, and play a significant role in energy dissipation and anti-scouring.

[0043] Ton bags 7 are arranged at the bottom folding points and overlaps of the bamboo plywood and the anti-seepage membrane cloth 8 and at the backwater side of the upstream steel membrane sealed cofferdam 1 and the downstream steel membrane sealed cofferdam 6 to increase the counterweight to resist the lateral water pressure.

[0044] The present invention provides a construction method of a combined cofferdam, as follows:

[0045] (1) Determine the depth and width of the diversion channel by calculating the flow rate of the river to ensure that the flow capacity is met;

[0046] (2) Figure 1 As shown, a diversion channel is formed by using a concrete bottom plate 3 and a concrete retaining wall 4, which effectively prevents leakage of groundwater and cofferdam during flow and prevents water exchange inside and outside the cofferdam;

[0047] (3) Figure 2 As shown, a diversion system is formed by using double-row piles 2, energy dissipation pool 5, bamboo plywood and anti-seepage membrane cloth 8, base 9, earth bags 10, cement bags 11, and steel sheet piles 12 to reduce the scouring of the cofferdam caused by the large height difference between upstream and downstream, large flow rate and flow velocity;

[0048] (4) Figure 3 As shown, the energy dissipation pool 5 is used to generate turbulence in the pool for the high-speed water flow, consume the water flow energy and slow down the impact force of the water flow entering the river channel, thus playing the role of energy dissipation and anti-impact;

[0049] (5) Figure 4 As shown, a channel steel truss 13 is used as the main structure of the upstream steel membrane end sealing cofferdam and the downstream steel membrane end sealing cofferdam, and is connected into a whole with a φ48 steel pipe 14 and a φ160mm log 15 to ensure structural stability and flow capacity, and create dry channel operation conditions;

[0050] The main advantages of the present invention are:

[0051] (1) Stable structure, strong anti-seepage performance, strong flow capacity and strong stability;

[0052] (2) Increase construction space and create dry trench operation conditions;

[0053] (3) Effectively prevent leakage of groundwater and cofferdam during flow, and effectively prevent water exchange inside and outside the cofferdam;

[0054] (4) Effectively reduce the scouring damage to the cofferdam and existing river channel caused by large upstream and downstream elevation differences and high flow and velocity;

[0055] (5) Enhance the bearing capacity and anti-deformation capacity of the cofferdam foundation, improve the hazards caused by adverse geology, and slow down the seepage rate;

[0056] (6) Ensure the overall construction environment and construction quality, and at the same time achieve reasonable allocation of river water resources during construction.

[0057] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A combined cofferdam, characterized in that: include: An upstream steel film sealed cofferdam (1) located upstream of the river channel, and a downstream steel film sealed cofferdam (6) located downstream of the river channel; The diversion channel comprises a base (9) formed by compacting original soil and partial stones, a double row of piles (2) located on the side of the base (9), and bamboo plywood and anti-seepage membrane cloth (8) laid on the surface layer of the double row of piles (2) and the surface layer of the base; An energy dissipation pool (5) is provided at the downstream outlet area of ​​the diversion channel; Ton bags (7) are arranged at the bottom folding points and overlapping parts of the bamboo plywood and the anti-seepage membrane cloth (8) and at the backwater side of the upstream steel membrane sealed cofferdam (1) and the downstream steel membrane sealed cofferdam (6).

2. A combined cofferdam according to claim 1, characterized in that: The height of the upstream steel membrane sealed cofferdam (1) is 4.5 m, and the height of the downstream steel membrane sealed cofferdam (6) is 3.5 m.

3. A combined cofferdam according to claim 1, characterized in that: The diversion channel further comprises a concrete base plate (3) and a concrete retaining wall (4); the concrete base plate (3) is arranged above the bamboo plywood and the anti-seepage membrane (8); the concrete retaining wall (4) is arranged on both sides of the concrete base plate (3); and the surface layer of the double-row piles (2) and the concrete retaining wall (4) are paved with the bamboo plywood and the anti-seepage membrane (8).

4. A combined cofferdam according to claim 3, characterized in that: The double-row piles (2) include a single-row steel pipe pile located on one side of the concrete retaining wall (4) and a double-row steel pipe pile located on the other side of the concrete retaining wall (4). The double-row steel pipe piles are connected as a whole via a rack pipe (17). The surface layers of the single-row steel pipe piles and the double-row steel pipe piles are both paved with the bamboo plywood and the anti-seepage membrane cloth (8).

5. A combined cofferdam according to claim 4, characterized in that: The middle of the double-row steel pipe piles and the back of the single-row steel pipe piles are filled with earth bags (10), and the earth bags (10) filled in the middle of the double-row steel pipe piles are exposed for 4.5 m.

6. A combined cofferdam according to claim 3, characterized in that: The concrete base plate (3) is cast in situ using C30 commercial concrete and has a thickness of 300 mm. The concrete retaining wall (4) is equipped with φ14 steel bars and has a width of 500 mm and a height of 1200 mm.

7. The combined cofferdam according to claim 1, characterized in that: A plurality of groups of steel sheet piles (12) are arranged in the downstream outlet area of ​​the diversion channel, and the energy dissipation pool (5) is arranged between the plurality of groups of steel sheet piles (12).

8. A combined cofferdam according to claim 4, characterized in that: It also comprises cement bags (11), a plurality of cement bags (11) are hung on the single-row steel pipe piles and the double-row steel pipe piles, and the plurality of cement bags (11) are pressed on the surface of the bamboo plywood and the anti-seepage membrane cloth (8).

9. A combined cofferdam according to any one of claims 1 to 8, characterized in that: The upstream steel membrane sealed end cofferdam (1) and the downstream steel membrane sealed end cofferdam (6) are both composed of channel steel trusses (13) and are connected and fixed by φ48 steel pipes (14) and φ160mm logs (15) to form a whole.

10. A combined cofferdam according to claim 9, characterized in that: The front side of the channel steel truss (13) is paved with bamboo plywood and anti-seepage membrane cloth (8), and a plurality of sand bags (16) are hung on the channel steel truss (13), and the plurality of sand bags (16) are pressed on the surface of the bamboo plywood and the anti-seepage membrane cloth (8).

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