CN218540735U - Marine anti-seepage cofferdam - Google Patents

Abstract

The utility model provides an ocean anti-seepage cofferdam, which comprises a high-pressure rotary spraying pile foundation positioned at the water facing side and the water backing side and a steel pipe pile foundation positioned in the middle; a broken stone cushion layer and a dike core stone are sequentially arranged above the high-pressure jet grouting pile foundation, natural soil is arranged between the steel pipe piles of the steel pipe pile foundation, the broken stone cushion layer and backfilled medium coarse sand are sequentially arranged above the natural soil, two stone cushion layers and a grouted block stone protective surface are sequentially arranged above the dike core stone on the water facing side, and a bottom protective block stone is further arranged at the position of the foremost end of the water facing side; two stone cushion layers, a mixed inverted filter layer, a geotextile filter layer and bagged sand are sequentially arranged above the dike core stones on the backwater side. The utility model discloses can strengthen the stability of marine prevention of seepage cofferdam to be convenient for be under construction.

Description

Anti-seepage cofferdam for ocean

Technical Field

The utility model belongs to the technical field of the cofferdam, especially, relate to an ocean is with prevention of seepage cofferdam.

Background

When building hydraulic engineering, in order to build some hydraulic equipment that use for a long time, need carry out the drainage to the operational environment who builds equipment, therefore it is especially important to build interim water retaining structure. Most of hydraulic engineering all adopt the cofferdam as interim manger plate structure, and the effect of cofferdam prevents just that silt and water from getting into the position of construction equipment, conveniently discharges the water of inside and then is favorable to the engineering ground construction, and its stability concerns the success or failure of whole engineering.

In recent years, with the rapid development of economy in China, a large amount of infrastructure is built in a sea area, and therefore cofferdams need to be built in the sea area. However, due to the wave load in the sea area, the stability of the common cofferdam form is often insufficient, the cofferdam is greatly deformed by the impact of sea waves, the phenomena of sea water leakage and even cofferdam collapse are caused, and huge potential safety hazards are brought to cofferdam construction.

The Chinese patent application CN201911367123 provides a water-stopping cofferdam structure for the construction of a lower cross beam in the sea and a construction method thereof, which are applied between two bearing platforms in a shallow water area to perform hoop water stopping and comprise a horizontal supporting structure, a vertical supporting structure and a foot protection structure, wherein the horizontal supporting structure comprises a surrounding purlin and a steel pipe support; the vertical supporting structure comprises two locking steel pipe pile curtains, a longitudinal beam and an auxiliary pile, the two locking steel pipe pile curtains are respectively welded and fixed on the outer side of a surrounding purlin, and the locking steel pipe piles penetrate into the depth of a soft foundation; the longitudinal beam is longitudinally connected between the two surrounding purlins through a connecting piece and is positioned below the plane of the horizontal supporting structure, and the auxiliary piles are fixed below the longitudinal beam and are inserted into the deep part of the soft foundation; the toe guard structure comprises a filling layer and a high-pressure jet grouting pile. The water-stopping cofferdam structure for construction of the undersea beam provided by the invention has the advantages of assembly, good water-stopping effect, capability of resisting stronger water flow force and wave force, simple and rapid manufacture, transportation and installation, capability of saving cost and accelerating construction progress, and excellent engineering utilization value.

The Chinese patent CN201910357095 provides a method for reinforcing instability of a steel sheet pile cofferdam in an offshore soft soil foundation, which comprises the steps of firstly removing part of a surrounding purlin in a collapse area, pulling out a deformed steel sheet pile, backfilling a flaky stone in the collapse area, then driving the steel sheet pile again, throwing a stone block on the outer side of the newly-driven steel sheet pile, and driving a steel pipe pile on the inner side of the newly-driven steel sheet pile; then, after the water level in the cofferdam meets the construction requirements, mounting the enclosing purlin and the inner support, and firmly welding the bottom enclosing purlin with the top of the steel pipe pile; and finally, after dredging the bottom of the cofferdam, laying section steel and a reinforcing mesh, welding the section steel and the steel pipe piles, pouring the back sealing concrete layer by layer, arranging a circle of brick retaining wall on the top surface of the back sealing concrete after pouring, and arranging a side ditch and a water collecting well on the inner side of the brick retaining wall. The invention not only improves the safety and stability of the steel sheet pile cofferdam, but also accelerates the construction progress, and effectively solves the sudden instability of the steel sheet pile cofferdam.

However, the invention does not disclose a complete anti-seepage cofferdam for the ocean.

The marine anti-seepage cofferdam is convenient to construct, high in stability, economical and reasonable. The utility model provides an ocean is with prevention of seepage cofferdam, this structure can effectively improve the stability in cofferdam and easily at marine construction, can be used to the relevant engineering in marine cofferdam.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems, the utility model provides a technical scheme does:

the utility model provides an ocean is with prevention of seepage cofferdam, the prevention of seepage cofferdam includes that the high pressure jet grouting pile basis that is located the side of meeting water and side of backing water and the steel-pipe pile basis that is located the centre, steel-pipe pile basis includes a row near the side of meeting water and a row near the side of backing water steel-pipe pile; a broken stone cushion layer and a dike stone are sequentially arranged above the high-pressure jet grouting pile foundation on the water facing side and the water backing side, natural soil is filled between the steel pipe piles of the steel pipe pile foundation, the broken stone cushion layer and backfilled medium coarse sand are sequentially arranged above the natural soil of the steel pipe pile foundation, two stone cushion layers and a grout block stone facing are sequentially arranged above the dike stone on the water facing side, and a bottom protecting block stone covering a part of the steel pipe pile foundation, a part of the broken stone cushion layer and a part of the dike stone is further arranged at the position of the foremost end of the water facing side; and two stone cushion layers, a mixed inverted filter layer, a geotextile filter layer and bagged sand are sequentially arranged above the dike core stones on the back water side.

The utility model discloses in, the well coarse sand in the coarse sand 12 is not from the ocean in backfilling, and natural soil 13 then itself is ocean ground material.

In a specific embodiment, the dyke core stones (3) are filled with a single block of stone blocks with the weight of 10-100 kg; the bottom protecting block stone (4) is filled with a single block stone with the weight of 100-200 kg; the geotextile filter layer (9) comprises one or more layers of woven geotextile.

In a specific embodiment, the stone in the mortar-masonry stone facing (7) is a regular hexagon stone with a side length of 30-50 cm and a thickness of 5-15 cm; after stone materials used by the grouted block stone facing (7) are soaked, the uniaxial saturation ultimate compressive strength is not lower than 50Mpa, the strength grade of the used cement mortar is not lower than M15, and the strength grade of the used pointing cement mortar is not lower than M20; the mixed stone in the mixed inverted filter layer (8) is particularly stone slag or sand pebbles.

In one specific embodiment, the slope of the dyke core stone (3), i.e. the ratio of the height to the width of the slope formed by the dyke core stone, is 1: 1-2, the gradient of the bottom protection block stone (4), namely the ratio of the height to the width of a slope formed by the bottom protection block stone is 1:2 to 2.5.

In a specific embodiment, the pile diameter of the high-pressure jet grouting pile in the high-pressure jet grouting pile foundation (1) is 0.7-1.0 m, the center-to-center distance of the piles is 0.6-0.9 m, the pile diameter is larger than the center-to-center distance of the piles, and the foundation replacement rate is 85-95%; the diameter of the steel pipe pile in the steel pipe pile foundation (2) is 1.2-1.8 m, the pile distance between two adjacent steel pipe piles in the same row, namely the center distance of the two adjacent steel pipe piles is 1.4-2 m, and the pile distance is larger than the diameter of the steel pipe pile.

In a specific embodiment, the integral structure of the seepage-proofing cofferdam above the gravel cushion layer (11) is trapezoidal.

In a specific embodiment, the geotextile filter layer (9) has a mass per unit area of 300-500 g/m ³ The woven bag used by the bagged sand (10) is 70-90 g/m ² The sand in the bagged sand (10) is sand with the mud content less than or equal to 5 percent and the permeability coefficient more than or equal to 5 multiplied by 10 ^-3 cm/s medium coarse sand, and the compactness of the gravel cushion layer (11) is not less than 96%.

Preferably, a concrete wave wall (5) is further arranged above the two stone cushion layers (6) above the dike core stones (3) on the backwater side and close to the steel pipe pile foundation (2); and a twisted king block (14) formed by concrete is also arranged on one side of the concrete wave-blocking wall (5) close to the water-facing side, and the width of the twisted king block (14) is 1.2-1.8 m.

The utility model also provides a construction method in prevention of seepage cofferdam, the structure in prevention of seepage cofferdam is as above prevention of seepage cofferdam, the method includes following step:

firstly, driving a rotary spraying pile and a steel pipe pile within a design range according to design requirements, drilling and rotary spraying cement slurry while driving the rotary spraying pile, wherein the driving of the steel pipe pile comprises the steps of drilling and driving, the pile distance between two adjacent steel pipe piles between two rows of steel pipe piles is 3-8 m, preferably 5-6 m, and the height of the top of the steel pipe pile after construction is 1.5-5 m higher than that of the top of the rotary spraying pile, preferably 2-3 m higher than that of the top of the steel pipe pile;

secondly, paving a gravel cushion layer (11) with the thickness of 30-80 cm on the basis of the finished treatment;

step three: filling the dike core stone (3);

step four: the bottom rock block (4) and the two stone cushion layers (6) are cast and filled, and the grouted rock block protective face (7) is used for covering the two stone cushion layers (6) on the water facing side in time;

step five: laying a mixed inverted filter layer (8), a geotextile filter layer (9) and bagged sand (10) on the backwater side;

step six: and medium coarse sand (12) is backfilled above the gravel cushion (11) at the position of the steel pipe pile foundation (2).

In the utility model, in the first step, the length of the drill rod is measured and marked, so that the drilling depth and the re-spraying depth of the drill rod can be mastered, and the design is guaranteed; and the double-pipe method and the three-pipe method are used for grouting. In the second step of the utility model, the contents of slender and flat particles in the broken stone cushion layer are less than 20wt%, and the broken stone does not contain clay blocks, plants and other impurities; settlement should be reserved after the disposal of the gravels in bulk and bags. In the third step, the dyke core stone dumping and filling block stones are determined according to design requirements, construction capacity, and consideration of the influence of tide level and waves, and the layering and subsection construction sequence is determined. In the fourth step, the ratio of the maximum side length to the minimum side length of the stones in the bottom protection stones is not more than 1.52, and the influence of drift generated by the stones is considered according to natural conditions such as water depth, water flow, waves and the like when the bottom protection stones are thrown and filled; the content of slender and flat particles in the two-piece stone cushion layer is less than 20wt%, and after the two-piece stone is laid, the water-facing side is covered with a grouted block stone protective surface in time to prevent wind waves and water flow from scouring and damaging; if damaged, it should be repaired again. In the fifth step, the mixed inverted filter layer is constructed in a segmented and layered manner, and each layer is staggered by enough distance; the length of the geotextile filter layer is increased by a certain margin on the basis of the designed slope length, the strength of the nylon wire spliced by the laying blocks is not less than 150N, and after laying, protective layer construction and upper backfilling are carried out in time and are carried out from the slope toe to the slope top; the bagged sand is timely cast and filled after the geotextile filter layer is laid. In the sixth step, the coarse sand in the backfill is compacted by adopting a two-point resonance compaction method. In the seventh step, the concrete wave wall is manufactured in a cast-in-place mode, and the wave action in the construction period is considered.

Compared with the prior art, the beneficial effects of the utility model include:

the seepage-proofing cofferdam of the utility model adopts the high-pressure jet grouting pile foundation and the steel pipe pile foundation which are specially arranged and combined, thereby obviously improving the stability of the cofferdam, reducing the offshore construction difficulty and saving the construction cost; the utility model discloses use the compound water-blocking structure of two pieces of stone bed courses, mixed inverted filter, geotechnological cloth filter, sand in bags can effectively prevent and treat the infiltration of sea water, increase cofferdam stability. Generally speaking, the utility model discloses can strengthen the stability of marine prevention of seepage cofferdam to be convenient for be under construction.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a sectional view of the anti-seepage cofferdam of the utility model.

Fig. 2 is a plan view of a high-pressure jet grouting pile.

Illustration of the drawings:

1. high-pressure rotary spraying pile foundation; 2. a steel pipe pile foundation; 3. a dyke core stone; 4. protecting the bottom stone; 5. concrete wave walls; 6. two stone bedding layers; 7. protecting the surface of the grouted blockstone; 8. mixing the inverted filter layer; 9. a geotextile filter layer; 10. bagging sand; 11. a gravel cushion layer; 12. backfilling the medium coarse sand; 13. natural soil; 14. twisting a king word block.

Detailed Description

To facilitate understanding of the present invention, the present invention will be described more fully and specifically with reference to the accompanying drawings and preferred embodiments, but the scope of the present invention is not limited to the following specific embodiments.

Example 1

The anti-seepage cofferdam structure comprises a high-pressure rotary jet grouting pile foundation 1, a steel pipe pile foundation 2, dyke core stones 3 arranged along the upstream surface and the downstream surface and bottom protection block stones 4 arranged along the upstream surface, wherein the dyke core stones are filled on the high-pressure rotary jet grouting pile foundation 1, backfill sand 12 is filled between the dyke core stones 3 on the upstream side and the downstream side, the steel pipe pile foundation 2 is used for foundation reinforcement under the backfill sand, natural soil 13 is filled between the steel pipe piles, a broken stone cushion layer 11 is further arranged under the dyke core stones 3, the bottom protection block stones 4 and the backfill sand 12, two stone cushion layers 6 are respectively arranged on the upstream side and the downstream surface of the dyke core stones, a grout block stone protective surface 7 is further arranged on the upstream side dyke core stones 3 above the two stone cushion layers 6, and a mixed inverted filter layer 8, a geotextile filter layer 9 and a bagged sand 10 are further arranged on the downstream side dyke core stones 3 above the two stone cushion layers 6; the cofferdam is of a trapezoidal structure as a whole.

Preferably, a concrete wave wall 5 and a twisty queen block 14 are provided on the lee-side core stone 3. The concrete wave wall 5 and the wrest blocks 14 help prevent the reverse flow of seawater.

That is to say, the utility model provides an anti-seepage cofferdam, which comprises a high-pressure rotary jet grouting pile foundation positioned at the water-facing side and the back water side and a steel pipe pile foundation positioned in the middle; a broken stone cushion layer and a dike core stone are sequentially arranged above the high-pressure jet grouting pile foundation, natural soil is arranged between the steel pipe piles of the steel pipe pile foundation, the broken stone cushion layer and backfilled medium coarse sand are sequentially arranged above the natural soil, two stone cushion layers and a grouted block stone protective surface are sequentially arranged above the dike core stone on the water facing side, and a bottom protective block stone is further arranged at the position of the foremost end of the water facing side; two stone cushion layers, a mixed inverted filter layer, a geotextile filter layer and bagged sand are sequentially arranged above the dike core stone on the back water side.

The cofferdam body foundation in the embodiment adopts the high-pressure rotary spraying pile foundation and the steel pipe pile foundation, so that the stability of the cofferdam can be effectively improved, and the construction difficulty is reduced. And the seepage-proofing performance of the cofferdam body is obviously improved by using a composite water-blocking structure of two stone cushion layers, a mixed inverted filtering layer, a geotextile filtering layer and bagged sand.

In this exampleThe gradient of the dike core stone 3 is 1.5, and 0-100 kg of block stones are adopted; the slope of the bottom protecting lump stones 4 is 1. In this example, the two stone slabs 6 arranged on the water-facing side and the water-back side of the dyke core stone 3 are made of un-weathered hard granite slabs with good gradation and a grain size of 80-150 mm. In the example, the space between the dyke core stones 4 on the water-facing side and the water-backing side is filled with backfilled coarse sand 12, and the sand material with the medium sand and the above specification is adopted. In the example, the diameter of the high-pressure jet grouting pile is 0.8m, the center-to-center distance of the pile is 0.75m, and the foundation replacement rate is 89%; the diameter of the steel pipe pile is 1.5m, and the pile pitch is 1.6m. In the example, after stone materials used for the grouted blockstone facing 7 arranged on the two stone cushion layers 6 on the water-facing side are soaked, the uniaxial saturation ultimate compressive strength is 50Mpa, the strength grade of the used cement mortar is M15, and the strength grade of the used pointing cement mortar is M20. In this example, the mixed inverted filter 8 provided on the two stone mats 6 on the back water side is made of mixed stones with good gradation. In the example, the geotextile filter 9 arranged on the mixed inverted filter 8 has a mass per unit area of 400g/m ³ The filament woven geotextile. In this example, the woven bag used for the bagged sand 10 provided on the geotextile filter 9 is 80g/m ² Woven bag, the sand used is sand with mud content not more than 5% and permeability coefficient not less than 5X 10 ^-3 Medium grit in cm/s. In this example, the gravel cushion layer 11 provided under the cofferdam body is layered-rolled using a light road roller and the degree of compaction thereof is not less than 96%.

Example 2

The construction method of the stable impermeable cofferdam structure in the embodiment 2 comprises the following steps:

the method comprises the following steps: and (3) driving the high-pressure jet grouting pile and the steel pipe pile within the design range according to the design requirement, measuring the length of the drill rod, and marking the drill rod with a mark so as to master the drilling depth and the re-spraying depth of the drill rod.

Step two: and paving a 50 cm-thick gravel cushion layer 11 on the treated foundation, wherein the average contour line of the section of the embankment body after gravel and bagged gravel are thrown is not less than the designed section, the average thickness is not less than the designed thickness, and settlement is reserved.

Step three: and (3) filling 10-100 kg of dike core stones 3-2.4 m, namely the height of the whole dike core stone layer is 2.4m, and determining the layering and subsection construction sequence of the filling and throwing block stones according to the specific design requirements, construction capacity, tide level and wave influence.

Step four: and (3) filling bottom protection block stones 4 outside the dike core, considering the influence of natural conditions such as water depth, water flow and waves on drift of the block stones, then laying two pieces of stones 6, and covering the water-facing side with a mortar block stone protective surface 7 in time to prevent the damage caused by wind wave and water flow scouring, and if the damage is caused, repairing the blocks again.

Step five: laying the mixed inverted filter 8 layer by layer, wherein each layer is staggered by enough distance, and after laying the geotextile filter 9, constructing a protective layer and backfilling the upper part in time; the bagged sand 10 is to be timely cast and filled after the geotextile filter layer is laid. The height of the whole mixed inverted filter layer 8, the geotextile filter layer 9 and the bagged sand 10 is 2.4m.

Step six: and backfilling the coarse sand 12 to a preloading top elevation, and compacting by adopting a two-point resonance compaction method.

Preferably, the method further comprises the step seven: and (5) pouring the concrete wave-retaining wall 5, and considering the wave action in the construction period. Finally, a twisted Chinese character 'Wang' block (14) made of concrete is arranged.

The foregoing is a more detailed description of the present invention that is presented in conjunction with specific embodiments, and it is not intended that the present invention be limited to these specific embodiments. To the utility model discloses to the ordinary skilled person in technical field's the prerequisite that does not deviate from the utility model discloses under the design, can also make a plurality of simple deductions and replacement, all should regard as belonging to the utility model discloses a protection scope.

Claims (7)

1. The marine anti-seepage cofferdam is characterized by comprising a high-pressure jet grouting pile foundation (1) positioned on a water-facing side and a water-backing side and a steel pipe pile foundation (2) positioned in the middle, wherein the steel pipe pile foundation (2) comprises one row of steel pipe piles close to the water-facing side and one row of steel pipe piles close to the water-backing side; a broken stone cushion layer (11) and a dyke stone (3) are sequentially arranged above the high-pressure jet grouting pile foundation (1) on the water facing side and the water backing side, natural soil (13) is arranged between the steel pipe piles of the steel pipe pile foundation (2), a broken stone cushion layer (11) and backfilled coarse sand (12) are sequentially arranged above the natural soil (13) of the steel pipe pile foundation (2), two stone cushion layers (6) and a mortar block stone facing (7) are sequentially arranged above the dyke stone (3) on the water facing side, and a bottom protection block stone (4) covering a part of the steel pipe pile foundation (2), a part of the broken stone cushion layer (11) and a part of the dyke stone (3) is further arranged at the position of the foremost end of the water facing side; two stone cushion layers (6), a mixed inverted filter layer (8), a geotextile filter layer (9) and bagged sand (10) are sequentially arranged above the dike core stone (3) on the backwater side.

2. Impermeable cofferdam according to claim 1, characterized in that said core stones (3) are filled with a single block of stones having a weight comprised between 10 and 100 kg; the bottom protecting block stone (4) is filled with a single block stone with the weight of 100-200 kg; the geotextile filter layer (9) comprises one or more layers of woven geotextile.

3. The impermeable cofferdam of claim 2, characterized in that the stones in the grout stone facing (7) are regular hexagonal stones with side length of 30-50 cm and thickness of 5-15 cm; after stone materials used by the grouted block stone protective surface (7) are soaked, the uniaxial saturation ultimate compressive strength is not lower than 50Mpa, the strength grade of the used cement mortar is not lower than M15, and the strength grade of the used pointing cement mortar is not lower than M20; the mixed stone in the mixed inverted filter layer (8) is particularly stone slag or sand pebbles.

4. Impermeable cofferdam according to claim 1, characterized in that the slope of the dykes (3), i.e. the ratio of height to width of the slope formed by the dykes, is 1: 1-2, the gradient of the bottom protection block stone (4), namely the ratio of the height to the width of a slope formed by the bottom protection block stone is 1:2 to 2.5.

5. The impermeable cofferdam of claim 1, characterized in that the pile diameter of the high-pressure jet grouting piles in the high-pressure jet grouting pile foundation (1) is 0.7-1.0 m, the pile center spacing is 0.6-0.9 m, the pile diameter is larger than the pile center spacing, and the foundation replacement rate is 85-95%; the diameter of the steel pipe pile in the steel pipe pile foundation (2) is 1.2-1.8 m, the pile distance between two adjacent steel pipe piles in the same row, namely the center distance of the two adjacent steel pipe piles is 1.4-2 m, and the pile distance is larger than the diameter of the steel pipe pile.

6. Seepage-proofing cofferdam according to claim 1, characterized in that the structure of the seepage-proofing cofferdam above the gravel cushion (11) is overall trapezoidal.

7. Seepage-proofing cofferdam according to claim 1, characterized in that the geotextile filter (9) has a mass per unit area of 300-500 g/m ³ The woven bag used by the bagged sand (10) is 70-90 g/m ² The sand in the bagged sand (10) is sand with the mud content less than or equal to 5 percent and the permeability coefficient more than or equal to 5 multiplied by 10 ^-3 cm/s medium coarse sand, and the compactness of the gravel cushion layer (11) is not less than 96%.

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