CN114525817B - Construction method of horizontal seepage-proofing and vertical seepage-proofing combined structure - Google Patents

Abstract

The invention discloses a construction method for a combined structure of horizontal anti-seepage and vertical anti-seepage. The combined anti-seepage structure adopted includes a vertical anti-seepage wall (10), a composite anti-seepage engineering structure (12), a horizontal anti-seepage system, and a filtration and drainage system. system; the composite anti-seepage engineering structure (12) is composed of a vertical anti-seepage interior wall (12‑1) and an interior wall covering board (12‑3) extending from its upper part to the side of the solid waste storage yard/contaminated site, a vertical anti-seepage The seepage external wall (12-2) and the external wall covering plate (12-4) expanding outwards on its upper part; the horizontal anti-seepage system is composed of the base layer (5), the anti-seepage material protective layer (4 ), a horizontal anti-seepage layer (3), an ecological base (2), and an ecological layer (1). The invention satisfies the technical requirements of horizontal anti-seepage and vertical anti-seepage at the same time, realizes the greening and beautification of solid waste storage yards/contaminated sites, and has smooth drainage and excellent drainage water quality, not only saves clay resources, reduces earthwork usage, and is easy to construct , low cost and good effect.

Description

A construction method for a combined structure of horizontal anti-seepage and vertical anti-seepage

technical field

The invention belongs to the technical field of anti-seepage engineering construction for pollution prevention and control, and specifically relates to a construction method with a combined structure of horizontal anti-seepage and vertical anti-seepage, which can be widely used in ecological restoration of polluted sites, in-situ treatment of solid waste, and collection of waste water seepage , river water quality protection and other fields, it is more suitable for solid waste storage sites that require both horizontal anti-seepage and vertical anti-seepage requirements.

Background technique

Due to historical reasons, many enterprises produce a large amount of solid waste during the production process, such as steel slag from steel mills, copper smelting waste slag, stripping waste rock (soil) from mining, etc. A large amount of solid waste has been piled up for a long time to form a dressing and smelting slag field If rainwater enters these solid waste storage sites, harmful wastewater will be produced, and then these harmful wastewater will enter the groundwater or leak out, which will seriously affect the safety of the local water system, damage the soil quality, and affect Vegetation grows and destroys the local environmental quality.

At present, the main methods for disposing of these solid wastes are: off-site landfill, on-site stockpiling, and on-site solidification treatment. The anti-seepage methods adopted include horizontal anti-seepage and vertical anti-seepage.

For only a small amount of solid waste, off-site landfill is more feasible in the context of environmental protection, safety and reliability; due to historical reasons, it is also a practical way to manage and control a large amount of existing solid waste on-site.

Horizontal anti-seepage is to establish an anti-seepage layer in the horizontal direction of the surface of the solid waste dump to prevent rainwater or new water from the outside from entering the solid waste stack below, and to avoid solid waste pollution to produce new wastewater that pollutes groundwater.

Vertical anti-seepage is to establish a vertical barrier (anti-seepage wall) around the solid waste storage yard or within a certain depth range downstream of the groundwater flow to prevent the contaminated water from spreading and migrating to other waters and polluting the surrounding waters.

At present, the vertical anti-seepage and horizontal anti-seepage treatment of waste water generated by solid waste are treated separately. This construction method of vertical anti-seepage and horizontal anti-seepage measures respectively has a long construction period, complicated construction and high cost. How to combine horizontal anti-seepage and vertical anti-seepage to jointly construct a combined structure system of horizontal anti-seepage and vertical anti-seepage is of great significance for saving clay resources, reducing earthwork usage, simplifying construction procedures, and improving anti-seepage effects.

Contents of the invention

The purpose of the present invention is to solve the problems of poor anti-seepage effect, long construction period, complicated construction process and high cost in the prior art, and provide a method that can save clay resources, reduce earthwork usage, simple construction, low construction cost, The construction method of the combined structure of horizontal anti-seepage and vertical anti-seepage with good anti-seepage effect.

In order to achieve the above-mentioned purpose of the present invention, a construction method of a horizontal anti-seepage and vertical anti-seepage combined structure of the present invention adopts the following technical solutions:

The combined anti-seepage structure adopted by the construction method of a horizontal anti-seepage and vertical anti-seepage combined structure of the present invention comprises a vertical anti-seepage wall, a composite anti-seepage engineering structure, a horizontal anti-seepage system, and a filtration drainage system; the composite anti-seepage engineering The structure is composed of a vertical anti-seepage inner wall and an inner wall covering panel extending from its upper part to the side of the solid waste dump/contaminated site, a vertical anti-seepage outer wall and an outer wall covering panel extending outward on its upper part; The vertical anti-seepage wall is located at the lower part between the vertical anti-seepage inner wall and the vertical anti-seepage outer wall, and a vertical anti-seepage bonding layer is arranged at the bottom between the vertical anti-seepage inner wall and the vertical anti-seepage outer wall, and the vertical anti-seepage The concave space formed by the inner wall, the vertical anti-seepage outer wall and the vertical anti-seepage joint layer is the horizontal anti-seepage rainwater collection and drainage space; the horizontal anti-seepage system is located on the vertical anti-seepage inner wall near the solid waste storage yard/contaminated site Above the original base on one side, the horizontal anti-seepage system is composed of base layer, anti-seepage material protective layer, horizontal anti-seepage layer, ecological base, and ecological layer from bottom to top; There are drainage holes, and the inlet of the drainage hole is provided with a reverse filter layer and a filter layer in sequence, and the outlet of the drain hole is discharged to the horizontal anti-seepage rainwater collection space, and the reverse filter layer, filter layer, drainage hole, and horizontal anti-seepage rainwater collection The external drainage space together constitutes a filtration drainage system, and the size of the horizontal anti-seepage rainwater collection external drainage space is determined according to the regional environmental improvement and rainwater collection and discharge calculations; the construction method is as follows:

1) On the outer edge of the solid waste storage yard/contaminated site where horizontal anti-seepage and vertical anti-seepage are required, the vertical anti-seepage line is defined, and the original base of the solid waste storage yard/contaminated site is prepared according to the design elevation and slope requirements. ground level;

2) Construct a composite anti-seepage engineering structure according to the position of the vertical anti-seepage line; the composite anti-seepage engineering structure adopts a reinforced concrete structure, which is formed by pouring concrete after supporting formwork and binding steel bars; the drainage hole and the vertical anti-seepage inner wall are constructed synchronously ;

3) After the composite anti-seepage engineering structure is stable and accepted, the vertical anti-seepage wall is constructed. The vertical anti-seepage wall adopts plain concrete or three-axis cement mixing piles or high-pressure rotary grouting piles; the depth of the vertical anti-seepage wall must reach a permeability coefficient of less than 1x10 ^{- 7} anti-seepage soil layer, and the thickness of the anti-seepage soil layer with entry permeability coefficient less than 1x10 ^-7 is not less than 1000mm;

4) Construction of the base layer and protective layer of anti-seepage material: the base layer shall be filled with miscellaneous filling soil, compacted in layers, and the compaction density shall not be less than 0.95; the protective layer of anti-seepage material shall be plain soil, which shall be leveled and compacted. Contains impurities such as organic matter, crushed stones, grass and sawdust;

5) Construction of the reverse filter layer, the reverse filter layer adopts a circular filter layer package, contains graded gravel, and is outsourced with geotextile;

6) Construction filter layer, the filter layer adopts coarse sand and is wrapped around the circular reverse filter layer; the coarse sand is particles with a particle size greater than 0.075mm and exceeds 85% of the total weight;

7) Lay the horizontal anti-seepage layer, the horizontal anti-seepage layer adopts high-density polyethylene HDPE geotechnical anti-seepage membrane, and add a protective layer of geotextile;

8) Construction of the ecological base, the ecological base adopts planting soil, and plants are planted on the planting soil to form an ecological layer, and the plant species are determined according to the requirements of regional ecological environment protection and greening;

9) Construct the vertical anti-seepage bonding layer, and the vertical anti-seepage bonding layer adopts plain concrete.

Further, a horizontal cover plate is provided on the vertical anti-seepage inner wall and the vertical anti-seepage outer wall, the horizontal cover plate is made of concrete cover plate, and the horizontal cover plate has grate holes.

Combining the anti-seepage effect and construction cost, through the experimental research results and comparison, the thickness B1 of the vertical anti-seepage inner wall and the vertical anti-seepage outer wall is preferably in the range of 150-200mm; the thickness B2 of the vertical anti-seepage wall is 600mm- The range of 800mm is better, and the thickness of the vertical anti-seepage wall must meet the permeability coefficient of less than 1x10 ^-7 , and ensure that the depth meets the design requirements; The height H4 of the wall and the vertical anti-seepage outer wall is in the range of 1300-1800mm.

Further, the thickness of the base layer is 400-600 mm, and the thickness of each layer compacted by layers is not more than 200 mm; the thickness of the protective layer of anti-seepage material is 150-250 mm.

Further, the diameter of the circular reverse filter layer package is in the range of 360-450 mm, and the upper and lower heights of the circular reverse filter layer package need to be not less than 80 mm below the inlet of the drain hole and not less than 80 mm above the inlet of the drain hole; The thickness of the filter layer is 420-560mm; the thickness of the ecological base is 420-560mm.

Further, the horizontal anti-seepage layer is a high-density polyethylene (HDPE) geotechnical anti-seepage membrane with a thickness of 1.5 mm.

After adopting the above technical scheme, a construction method of a horizontal anti-seepage and vertical anti-seepage combined structure of the present invention has the following positive effects:

(1) The combined anti-seepage structure composed of vertical anti-seepage wall, composite anti-seepage engineering structure, horizontal anti-seepage system and filtration drainage system is adopted to meet the technical requirements of horizontal anti-seepage and vertical anti-seepage at the same time, and realize horizontal anti-seepage Perfect combination with vertical anti-seepage;

(2) The horizontal anti-seepage system is composed of base layer, anti-seepage material protective layer, horizontal anti-seepage layer, ecological base layer and ecological layer from bottom to top, which can meet the requirements of horizontal anti-seepage in solid waste storage yards/contaminated sites , and restored the ecology of the solid waste dump/polluted site, and realized the greening and beautification of the solid waste dump/polluted site;

(3) The vertical anti-seepage system consists of a vertical anti-seepage wall at the bottom, a double-layer structure of vertical anti-seepage inner wall and vertical anti-seepage outer wall at the upper part, and a combination of vertical anti-seepage bonding layers. The vertical anti-seepage effect is good and the construction is convenient ;

(4) The anti-filtration layer, filter layer, drainage holes, and horizontal anti-seepage rainwater collection and drainage space together constitute a filtration drainage system, which has smooth drainage and excellent drainage water quality.

(5) The present invention adopts sinking type horizontal anti-seepage, that is: rainwater penetrates to the horizontal anti-seepage layer through the ecological layer and the ecological base layer, and then flows downward along the filter layer, reverse filter layer, and drainage holes to the horizontal through the horizontal anti-seepage layer. The anti-seepage rainwater is collected and discharged from the outer drainage space; the structure of the sunken horizontal anti-seepage and vertical anti-seepage combination not only saves clay resources and reduces the amount of earthwork used, but also is easy to construct, low in cost and effective.

Description of drawings

Fig. 1 is the sectional view of the combined anti-seepage structure designed by the construction method of a kind of horizontal anti-seepage and vertical anti-seepage combined structure of the present invention.

Reference signs: 1-ecological layer; 2-ecological base; 3-horizontal anti-seepage layer; 4-protective layer of anti-seepage material; 5-base layer; ); 7- drainage hole; 8- reverse filter layer; 9- filter layer; 10- vertical anti-seepage wall; 11- vertical anti-seepage joint layer; 12- composite anti-seepage engineering structure; 12-1- vertical anti-seepage inner wall ; 12-2-vertical anti-seepage outer wall; 12-3-inner wall covering board; 12-4-external wall covering board; 13-horizontal anti-seepage rainwater collection and drainage space; 14 horizontal cover board.

Detailed ways

In order to further describe the present invention, the construction method of a combined structure of horizontal anti-seepage and vertical anti-seepage according to the present invention will be further described in detail below in conjunction with the accompanying drawings.

Seen from the combined anti-seepage structure sectional view designed by the construction method of a kind of horizontal anti-seepage and vertical anti-seepage composite structure of the present invention shown in Fig. 1, a kind of construction method of horizontal anti-seepage and vertical anti-seepage composite structure of the present invention, The combined anti-seepage structure adopted comprises a vertical anti-seepage wall 10, a composite anti-seepage engineering structure 12, a horizontal anti-seepage system, a filtration drainage system, and a horizontal cover plate 14; the composite anti-seepage engineering structure 12 is composed of a vertical anti-seepage inner wall 12-1 and the inner wall covering board 12-3 extending from its upper part to the side of the solid waste storage yard/contaminated site, the vertical anti-seepage outer wall 12-2 and the outer wall covering board 12-4 extending outward on its upper part Composition; the vertical anti-seepage wall 10 is located at the lower part between the vertical anti-seepage inner wall 12-1 and the vertical anti-seepage outer wall 12-2, between the vertical anti-seepage inner wall 12-1 and the vertical anti-seepage outer wall 12 The bottom between -2 is provided with a vertical anti-seepage bonding layer 11, the concave space formed by the vertical anti-seepage inner wall 12-1, the vertical anti-seepage outer wall 12-2, and the vertical anti-seepage bonding layer 11 is used for horizontal anti-seepage rainwater collection The outer row space 13; the horizontal cover plate 14 adopts a concrete cover plate, and the horizontal cover plate 14 is covered on the vertical anti-seepage inner wall 12-1 and the vertical anti-seepage outer wall 12-2; the horizontal anti-seepage system is located in the vertical anti-seepage The seepage inner wall 12-1 is above the original base layer 6 on the side close to the solid waste storage yard/contaminated site. The horizontal anti-seepage system is composed of the base layer 5, the anti-seepage material protective layer 4, and the horizontal anti-seepage layer 3 from bottom to top. , ecological base 2, and ecological layer 1 are combined; drain holes 7 are arranged at intervals in the vertical anti-seepage inner wall 12-1, and anti-filter layers 8, filter layers 9, and drain holes 7 are arranged in sequence at the entrance of the drain holes 7. The outlet is discharged to the horizontal anti-seepage rainwater collection and drainage space 13. The reverse filter layer 8, the filter layer 9, the drainage hole 7, and the horizontal anti-seepage rainwater collection and drainage space 13 together constitute a filtration drainage system. According to the regional environmental improvement and rainwater collection and The discharge calculation determines the space size of the horizontal anti-seepage rainwater collection and discharge space 13 .

The technical parameters of the combined anti-seepage structure adopted in the embodiment are:

The thickness B1 of the vertical anti-seepage inner wall 12-1 and the vertical anti-seepage outer wall 12-2 is 150-200 mm, the thickness B2 of the vertical anti-seepage wall 11 is 600 mm-800 mm, the inner wall covering board 12-3, the outer wall The thickness H3 of the wall covering board 12-4 is 150-200mm, the height H4 of the vertical anti-seepage inner wall 12-1 and the vertical anti-seepage outer wall 12-2 is 1300-1800mm; the thickness of the base layer 5 is 500mm, The thickness of each solid layer is not more than 200mm; the thickness of the anti-seepage material protective layer 4 is 200mm; the diameter of the circular filter layer bag is in the range of 400mm; the thickness of the filter layer 9 is 500mm; the thickness of the ecological base 2 is 500mm; The seepage layer 3 is a high-density polyethylene (HDPE) geotechnical anti-seepage membrane with a thickness of 1.5mm; the upper and lower heights of the circular reverse filter layer package also need to be located at 100mm below and 100mm above the inlet of the drainage hole.

Its construction method is as follows:

1) On the outer edge of the solid waste storage yard/polluted site where horizontal anti-seepage and vertical anti-seepage are required, the vertical anti-seepage line is defined, and the original base of the solid waste storage yard/contaminated site is carried out according to the design elevation and slope requirements 6 the site is level;

2) According to the position of the vertical anti-seepage line, construct the composite anti-seepage engineering structure 12; the composite anti-seepage engineering structure 12 adopts a reinforced concrete structure, which is formed by pouring concrete after formwork and binding steel bars; the drain hole 7 is connected with the vertical anti-seepage inner The wall 12-1 is constructed simultaneously; the composite anti-seepage engineering structure 12 adopts a reinforced concrete structure, the diameter of the steel bar in the concrete is 14mm, and the spacing between the steel bars is 200mm; the drainage hole 7 is made of pre-embedded φ100 plastic steel pipes, the spacing is 2000mm, and the vertical position is determined according to the design;

3) After the composite anti-seepage engineering structure 12 is stable and accepted, the vertical anti-seepage wall 10 is constructed, and the vertical anti-seepage wall 10 adopts C15 plain concrete or three-axis cement mixing piles or high-pressure jet grouting piles;

4) Construction of the base layer 5 and the anti-seepage material protective layer 4: the base layer 5 adopts miscellaneous fill and compacts in layers; the anti-seepage material protective layer 4 adopts plain soil and is leveled and compacted;

5) Construction of the reverse filter layer 8, the reverse filter layer 8 adopts a circular reverse filter layer bag, contains graded crushed stones, and is outsourced with geotextiles;

6) Construction filter layer 9, filter layer 9 adopts coarse sand and is arranged around the circular reverse filter layer;

7) laying the horizontal anti-seepage layer 3, the horizontal anti-seepage layer 3 adopts high-density polyethylene HDPE geotechnical anti-seepage membrane, and adds a protective layer of geotextile;

8) construction of ecological base 2, ecological base 2 adopts planting soil, plants are planted on the planting soil to form ecological layer 1, and plant varieties are determined according to the requirements of regional ecological environment protection and greening;

9) Construction of the vertical anti-seepage bonding layer 11, the vertical anti-seepage bonding layer 11 adopts plain concrete;

10) Complete the fabrication and installation of the horizontal cover plate 14 .

The test verification shows that the present invention can save more than 30% of the civil construction cost compared with the horizontal anti-seepage method and the vertical anti-seepage method respectively, and can effectively save the land use area and further save the land resources.

The invention is applicable to solid waste heaps of different shapes, such as ground, pits, and mountain depressions, and is especially suitable for the situation where the ground is required to be flat.

Claims (9)

1. A construction method of a horizontal seepage-proofing and vertical seepage-proofing combined structure is characterized by comprising the following steps of: the adopted combined seepage-proofing structure comprises a vertical seepage-proofing wall (10), a composite seepage-proofing engineering structure (12), a horizontal seepage-proofing system and a filtering drainage system; the composite impermeable engineering structure (12) is composed of a vertical impermeable inner wall (12-1), an inner wall covering plate (12-3) which is arranged at the upper part of the vertical impermeable inner wall and extends to one side of a solid waste storage yard/polluted site, a vertical impermeable outer wall (12-2) and an outer wall covering plate (12-4) which is arranged at the upper part of the vertical impermeable outer wall and extends outwards; the vertical impervious wall (10) is positioned at the lower part of the position between the vertical impervious inner wall (12-1) and the vertical impervious outer wall (12-2), a vertical impervious bonding layer (11) is arranged at the bottom between the vertical impervious inner wall (12-1) and the vertical impervious outer wall (12-2), and a concave space formed by the vertical impervious inner wall (12-1), the vertical impervious outer wall (12-2) and the vertical impervious bonding layer (11) is a horizontal impervious rainwater collecting outer emptying space (13); the horizontal seepage-proofing system is positioned on an original base layer (6) of a vertical seepage-proofing inner wall (12-1) close to one side of a solid waste storage yard/polluted site, and is formed by combining a base layer (5), a seepage-proofing material protection layer (4), a horizontal seepage-proofing layer (3), an ecological base layer (2) and an ecological layer (1) from bottom to top; a drain hole (7) is arranged in the vertical impermeable inner wall (12-1) at intervals, a reverse filtering layer (8) and a filter layer (9) are sequentially arranged at the inlet of the drain hole (7), the outlet of the drain hole (7) is discharged to a horizontal impermeable rainwater collecting outer emptying room (13), the reverse filtering layer (8), the filter layer (9), the drain hole (7) and the horizontal impermeable rainwater collecting outer emptying room (13) jointly form a filtering drain system, and the space size of the horizontal impermeable rainwater collecting outer emptying room (13) is determined according to regional environment remediation and rainwater collecting and discharging calculation; the construction method comprises the following steps:

1) Defining a vertical seepage-proofing line at the outer edge of a solid waste storage yard/polluted site needing horizontal seepage-proofing and vertical seepage-proofing, and leveling the site of an original base layer (6) of the solid waste storage yard/polluted site according to the design elevation and gradient requirements;

2) Constructing a composite impermeable engineering structure (12) according to the position of the vertical impermeable line; the composite seepage-proofing engineering structure (12) is formed by adopting a reinforced concrete structure and pouring concrete after supporting a formwork and binding reinforcing steel bars; the drain hole (7) and the vertical impermeable inner wall (12-1) are constructed synchronously;

3) After the composite impervious engineering structure (12) is stably checked and accepted, constructing a vertical impervious wall (10), wherein the vertical impervious wall (10) adopts plain concrete or triaxial cement stirring piles or high-pressure jet grouting piles;

4) Construction of a base layer (5) and an impermeable material protective layer (4): the foundation layer (5) adopts miscellaneous fill, and is compacted in layers; the impermeable material protective layer (4) adopts plain soil, and is leveled and compacted;

5) Constructing a reverse filtering layer (8), wherein the reverse filtering layer (8) adopts a round reverse filtering layer bag, contains graded broken stone and is wrapped with geotextile;

6) Constructing a filter layer (9), wherein the filter layer (9) adopts coarse sand and is wrapped and distributed around the round reverse filter layer;

7) Paving a horizontal impermeable layer (3), wherein the horizontal impermeable layer (3) is a high-density polyethylene HDPE geotechnical impermeable film, and a geotechnical cloth protective layer is added on the horizontal impermeable layer;

8) Constructing an ecological base layer (2), wherein the ecological base layer (2) adopts planting soil, plants are planted on the planting soil to form an ecological layer (1), and plant varieties are determined according to requirements of regional ecological environment protection and greening;

9) And constructing a vertical seepage-proofing bonding layer (11), wherein the vertical seepage-proofing bonding layer (11) adopts plain concrete.

2. The method for constructing a combined horizontal and vertical impermeable structure according to claim 1, wherein: the adopted combined anti-seepage structure also comprises a horizontal cover plate (14), wherein the horizontal cover plate (14) is a concrete cover plate, and the horizontal cover plate (14) covers the vertical anti-seepage inner wall (12-1) and the vertical anti-seepage outer wall (12-2).

3. The method for constructing a combined horizontal and vertical impermeable structure according to claim 2, wherein: the thickness B1 of the vertical impermeable inner wall (12-1) and the vertical impermeable outer wall (12-2) is 150-200 mm, the thickness B2 of the vertical impermeable wall (10) is 600-800 mm, the thickness H3 of the inner wall covering plate (12-3) and the outer wall covering plate (12-4) is 150-200 mm, and the height H4 of the vertical impermeable inner wall (12-1) and the vertical impermeable outer wall (12-2) is 1300-1800 mm.

4. A method of constructing a combined horizontal and vertical barrier structure as claimed in claim 3, wherein: the thickness of the base layer (5) is 400-600 mm, and the thickness of each layer compacted by layering is not more than 200mm; the thickness of the impermeable material protective layer (4) is 150-250 mm.

5. The method for constructing a combined horizontal and vertical impermeable structure as claimed in claim 1, 2, 3 or 4, wherein: the diameter of the round reverse filtering layer packet is in the range of 360-450 mm.

6. The method for constructing a combined horizontal and vertical seepage-proofing structure according to claim 5, wherein: the thickness of the filter layer (9) is 420-560 mm.

7. The method for constructing a combined horizontal and vertical impermeable structure according to claim 6, wherein: the thickness of the ecological base layer (2) is 420-560 mm.

8. The method for constructing a combined horizontal and vertical impermeable structure according to claim 7, wherein: the horizontal impermeable layer (3) is a high-density polyethylene HDPE geotechnical impermeable film with the thickness of 1.5 mm.

9. The method for constructing a combined horizontal and vertical impermeable structure according to claim 8, wherein: the upper and lower heights of the round inverted filter bag also need to be respectively positioned below the inlets of the drain holes and not less than 80mm, and the upper heights of the round inverted filter bag are also not less than 80mm.