Cement-soil mixing pile sealing wall

Abstract

The utility model provides a cement-soil mixing pile sealing wall, which comprises cement-soil mixing piles, Larsen steel sheet piles, a joint pile cap, a first sealing film, geotextile and a second sealing film, the Larsen steel sheet piles are connected in a head-to-tail mode to form a fence, the cement-soil mixing piles are arranged at intervals along the inner wall of the fence, the cement-soil mixing piles and the top of the fence are connected into an integrated whole through the filled joint pile cap, the inner side of the joint pile cap is pre-buried with the first sealing film, the first sealing film covers the internal area surrounded by the fence and the cement-soil mixing piles from above the joint pile cap, the geotextile is laid below the first sealing film, the second sealing film is laid below the geotextile, and a sand cushion layer is laid above the first sealing film. The utility model forms a three-dimensional composite sealing system by combining the vertical anti-seepage system of the joint curtain of the cement-soil mixing piles and the Larsen steel sheet piles and the horizontal anti-seepage system of the double-layer HDPE film, greatly reduces the risk of leakage, and combines the Larsen steel sheet piles with good soil retaining property and the cement-soil mixing piles with good anti-seepage property and low cost.

Description

Technical Field

[0001] This utility model relates to the field of sealing wall technology, and in particular to a sealing wall for cement-soil mixing piles. Background Technology

[0002] In environmental protection and underground engineering construction, it is often necessary to construct well-sealed vertical barrier walls or cofferdams to prevent the migration of pollutants or the intrusion of groundwater. Currently, there are various common types of sealing walls, but all of them have certain limitations.

[0003] A common approach is to construct retaining walls using only Larssen sheet piles. Larssen sheet piles offer advantages such as high strength, fast construction speed, and good water-stopping effect. However, their disadvantages are also quite obvious: for example, patent application CN204589991U discloses a vacuum preloaded sheet pile with strong sealing. The sheet piles are connected by interlocking joints. Although a water-stopping layer is set at the interlocking joints, there is a risk of leakage between the interlocking joints, especially when the verticality deviation of the pile construction is large, the interlocking joints may not be fully engaged, forming leakage channels; secondly, sheet piles are flexible structures, and in soft soil foundations, their overall rigidity is insufficient, which may lead to large deformations, affecting the sealing effect and structural safety.

[0004] Another approach is to use cement-soil mixing piles to continuously overlap and form a cement-soil mixing wall (CSM) of uniform thickness. This type of wall has good overall impermeability, but the construction equipment is large and the cost is high, and it is not very adaptable to obstacles in the strata. Summary of the Invention

[0005] This utility model aims to address the shortcomings of existing technologies by providing a cement-soil mixing pile sealing wall.

[0006] To achieve the above objectives, this utility model adopts the following technical solution:

[0007] A cement-soil mixing pile sealing wall includes cement-soil mixing piles, Larssen sheet piles, combined pile caps, a first sealing membrane, geotextile, and a second sealing membrane. The Larssen sheet piles are connected end to end to form a wall. The cement-soil mixing piles are spaced apart along the inner wall of the wall. The cement-soil mixing piles and the top of the wall are connected as one unit by the filled combined pile caps. The first sealing membrane is pre-embedded on the inner side of the combined pile caps. The first sealing membrane covers the internal area enclosed by the wall and the cement-soil mixing piles from above the combined pile caps. Geotextile is laid below the first sealing membrane, the second sealing membrane is laid below the geotextile, and a sand cushion layer is laid above the first sealing membrane.

[0008] The edges of the Larssen sheet piles connected end to end are rolled outward to form rolled edges, and adjacent rolled edges are hooked together.

[0009] The rolled edge is fitted with a water-swellable sleeve.

[0010] The height of the wall is higher than the height of the cement-soil mixing piles.

[0011] The edge of the first sealing membrane extends toward the inner bottom of the combined pile cap.

[0012] The first and second sealing films are HDPE films.

[0013] The cement mixing piles are installed at intervals of 3 to 7 Larssen steel sheet piles.

[0014] The geotextile is a polyester filament clay geotextile.

[0015] The beneficial effects of this utility model are as follows: This utility model consists of a three-dimensional composite sealing system composed of a vertical anti-seepage system of cement-soil mixing piles and Larssen steel sheet piles combined with a horizontal anti-seepage system of double-layer HDPE membrane, which greatly reduces the risk of leakage. The combined pile cap connects the discrete cement-soil mixing piles and the continuous Larssen steel sheet pile wall into a rigid platform at the top. The combination of Larssen steel sheet piles with good soil retention and cement-soil mixing piles with good anti-seepage properties and low cost enhances the overturning resistance and deformation resistance of the entire wall structure, and is especially suitable for soft soil foundations. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the longitudinal section structure of this utility model;

[0018] Figure 3 This is a schematic diagram of the structure of the rolled plate section of the Larssen sheet pile of this utility model;

[0019] In the diagram: 1-Cement-soil mixing pile; 2-Wall; 21-Rolled edge; 22-Water-swellable sleeve; 3-Combined pile cap; 4-Sand cushion layer; 5-First sealing membrane; 6-Geotextile; 7-Second sealing membrane;

[0020] The following will describe in detail the embodiments of this utility model with reference to the accompanying drawings. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0022] A cement-soil mixing pile sealing wall includes cement-soil mixing piles 1, Larssen sheet piles, combined pile caps 3, a first sealing membrane 5, geotextile 6, and a second sealing membrane 7. The Larssen sheet piles are connected end to end to form a wall 2. The cement-soil mixing piles 1 are spaced along the inner wall of the wall 2. The top of the cement-soil mixing piles 1 and the wall 2 are connected as one unit by the filled combined pile caps 3. The first sealing membrane 5 is pre-embedded on the inner side of the combined pile caps 3. The first sealing membrane 5 covers the internal area enclosed by the wall 2 and the cement-soil mixing piles 1 from above the combined pile caps 3. Geotextile 6 is laid below the first sealing membrane 5. The second sealing membrane 7 is laid below the geotextile 6. A sand cushion layer 4 is laid above the first sealing membrane 5.

[0023] The edges of the Larssen sheet piles connected end to end are rolled outward to form rolled edges 21, and adjacent rolled edges 21 are hooked together. A water-swellable sleeve 22 is fitted onto the rolled edge 21. During piling, the rolled edge 21 of one Larssen sheet pile will embed into the rolled edge 21 of another Larssen sheet pile, forming a continuous integral wall through interlocking. This provides the main tensile and shear strength, ensuring the integrity of the wall structure. One or more hollow, tortuous cavities are formed at the interlocking point of the two rolled edges 21. The water-swellable sleeve 22 is a tubular or strip-shaped sealing element made of water-swellable rubber and is installed inside the rolled edge interlock of the Larssen sheet pile. When external moisture attempts to seep in through the interlock gaps, the water-swellable sleeve 22 absorbs the moisture and expands rapidly, increasing in volume to several times its original size, squeezing and filling all the tiny, irregular gaps inside the interlock.

[0024] The height of the enclosure wall 2 is higher than that of the cement-soil mixing pile 1. The raised enclosure wall forms a reliable water-retaining weir, increases the fault tolerance space, and provides additional water storage capacity. At the same time, it combines the Larssen steel sheet piles with good tensile and shear strength and continuity with the cement-soil mixing pile 1 for seepage prevention and foundation reinforcement.

[0025] The edge of the first sealing membrane 5 extends toward the inner bottom of the combined pile cap 3 to ensure a port seal.

[0026] The first sealing film 5 and the second sealing film 7 are HDPE films.

[0027] The cement mixing pile 1 is set at intervals of 3 to 7 Larssen steel sheet piles. The cement mixing pile 1 not only provides a reliable seepage barrier, but also serves as part of the support structure, working in conjunction with the Larssen steel sheet piles. This reduces the penetration depth and cross-sectional dimensions of the Larssen steel sheet piles, achieving a balance between economy and safety.

[0028] The geotextile 6 is a polyester filament clay geotextile, which can effectively prevent the upper sand cushion layer or backfill material from puncturing and damaging the sealing membrane, plays an important role in buffering and protecting the main seepage prevention layer, and extends the service life of the sealing system.

[0029] During construction, a vibratory pile driver was used to drive steel sheet piles sequentially into the foundation, and they were interconnected through interlocking joints to form a closed enclosure wall 2. Verticality was strictly controlled during pile driving to ensure a tight interlocking joint. After construction, the top elevation of enclosure wall 2 was controlled at +5.0 meters. Cement-soil mixing piles 1 were constructed on the inner side of enclosure wall 2. Cement-soil mixing piles 1 were tangent to the bending point of the outer wall of the steel sheet piles, using a twin-shaft mixing pile machine. The pile diameter was 700mm, the pile spacing was 500mm, and the pile length was 10 meters. The Larssen steel sheet piles were 13 meters higher than the cement-soil mixing piles. During construction, uniform mixing was ensured to form a continuous and dense cement-soil mixing pile wall. The loose soil on top of the cement-soil mixing piles 1 and the Larssen steel sheet pile enclosure wall 2 was removed to expose fresh pile heads. Reinforcing mesh was tied, and formwork was erected to form a trapezoidal trench-shaped formwork system covering the top of all piles, such as... Figure 2 As shown, C30 grade ready-mixed concrete was used for in-situ casting to form a rectangular cross-section composite pile cap 3. During casting, the concrete was ensured to be vibrated and compacted. After the concrete in the composite pile cap 3 reached its design strength, the site inside the enclosure wall 2 was cleaned, leveled, and compacted. Then, a 1.5mm thick HDPE second sealing membrane 7 was laid, covering the entire bottom of the enclosure wall 2. The membranes were welded together using a double-track hot-melt welding machine to form a complete bottom sealing layer. On top of the second sealing membrane 7, a 400g / m² layer was laid. 2 Polyester filament spunbond geotextile 6 is used as a protective layer, followed by a 1.5mm thick HDPE first sealing membrane 5. Before laying, the edge portion of the first sealing membrane 5 is pre-laid inside the template of the combined pile cap 3, and then the concrete of the combined pile cap 3 is poured, thus firmly embedding the edge of the first sealing membrane 5 within it. After demolding, the main body of the first sealing membrane 5 is laid downwards to cover the entire internal area and is tightly attached to the geotextile 6. Its embedded edge extends downwards below the bottom of the combined pile cap 3 and folds outwards, partially covering the side and top surfaces of the combined pile cap 3. Finally, it is fixed to the side of the combined pile cap 3 with special pressure strips and bolts to ensure a perfect seal at the port. On top of the first sealing membrane 5, a 300mm thick medium-coarse sand cushion layer 4 is laid and leveled and compacted. This sand cushion layer 4 protects the first sealing membrane 5 below and can also serve as the base layer or guide layer for subsequent ground structures. Ultimately, a reliable sealing wall was formed, consisting of high-strength combined pile caps 3, which combines rigid support with flexible sealing, and tightly integrates vertical and horizontal seepage prevention.

[0030] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] The present invention has been described above with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made using the inventive concept and technical solution of the present invention, or direct application to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A cement-soil mixing pile sealing wall, characterized in that, The structure includes cement-soil mixing piles (1), Larssen sheet piles, combined pile caps (3), a first sealing membrane (5), geotextile (6), and a second sealing membrane (7). The Larssen sheet piles are connected end to end to form a wall (2). The cement-soil mixing piles (1) are spaced along the inner wall of the wall (2). The top of the cement-soil mixing piles (1) and the wall (2) are connected as one unit by the filled combined pile caps (3). The first sealing membrane (5) is pre-embedded on the inner side of the combined pile caps (3). The first sealing membrane (5) covers the inner area enclosed by the wall (2) and the cement-soil mixing piles (1) from above the combined pile caps (3). Geotextile (6) is laid below the first sealing membrane (5). The second sealing membrane (7) is laid below the geotextile (6). A sand cushion layer (4) is laid above the first sealing membrane (5).

2. The cement-soil mixing pile sealing wall according to claim 1, characterized in that, The edges of the Larsen sheet piles connected end to end are rolled outward to form rolled edges (21), and adjacent rolled edges (21) are hooked together.

3. A cement-soil mixing pile sealing wall according to claim 2, characterized in that, A water-swellable sleeve (22) is fitted onto the rolled edge (21).

4. A cement-soil mixing pile sealing wall according to claim 1, characterized in that, The height of the wall (2) is higher than the height of the cement-soil mixing pile (1).

5. A cement-soil mixing pile sealing wall according to claim 1, characterized in that, The edge of the first sealing membrane (5) extends toward the inner bottom of the combined pile cap (3).

6. A cement-soil mixing pile sealing wall according to claim 3, characterized in that, The first sealing film (5) and the second sealing film (7) are HDPE films.

7. A cement-soil mixing pile sealing wall according to claim 1, characterized in that, The cement-soil mixing piles (1) are set with 3 to 7 Larsen steel sheet piles at intervals.

8. A cement-soil mixing pile sealing wall according to claim 1, characterized in that, The geotextile (6) is a polyester filament clay geotextile.

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