Pluggable foundation pit supporting structure based on prefabricated parts

Abstract

The utility model discloses a pluggable foundation pit supporting structure based on prefabricated parts, and belongs to the technical field of water conservancy and building engineering design and construction. The foundation pit supporting structure comprises a plurality of hollow prefabricated pipe piles which are arranged in a foundation pit side by side at intervals, grouting holes are reserved in the hollow prefabricated pipe piles, a waterproof curtain is arranged in the position, between every two adjacent hollow prefabricated pipe piles, in the foundation pit, and sealing is formed between the waterproof curtain and the adjacent hollow prefabricated pipe piles; a prefabricated top beam is arranged on the top of the hollow prefabricated pipe pile, and a support is transversely arranged on the inner side of the prefabricated top beam. The stability of a supporting structure can be met, meanwhile, construction is rapid, pile foundations can be pulled out, the pile foundations can be used as the supporting structure or a main body structure foundation to be recycled, inter-pile high-pressure jet grouting piles are adopted for a rear row waterproof curtain, a percussion drill can be adopted for pile heads, the method can be applied to hard and complex geologic structures such as block stones and floating stones, adaptability is high, and meanwhile the jumping pile hole forming technology is adopted; the number of pile foundations is small, engineering efficiency is improved, and engineering investment is saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of water conservancy and building engineering design and construction, and specifically relates to a pluggable foundation pit supporting structure based on prefabricated components. Background Art

[0002] Foundation pit support is a measure of support, reinforcement and protection for the side walls of foundation pits to ensure the safety of underground structure construction and the surrounding environment of foundation pits. Common foundation pit support structures include pile support, underground continuous wall support, cement retaining wall, soil nail wall, etc. Its selection is related to the excavation depth of the foundation pit. The support scheme of single-row pile + support is generally used in foundation pits with larger excavation depths. Support is usually expensive, and in the field of water conservancy projects it can often reach 10% to 20% of the project investment. Pile rows use cast-in-place piles, SMW method piles, steel sheet piles, etc. Generally, cast-in-place piles are retained in the soil after the foundation pit construction is completed, and are less used in the main project. The support depth of SMW method piles is limited, and there is a certain depreciation in the recovery of steel. Steel sheet piles can be recycled, but they cannot be used as bearing pile foundations in combination with the main project, and the depreciation is large.

[0003] In view of the above-mentioned related technical characteristics, the inventor believes that the foundation pit support structure is expensive, often used as a temporary project, and cannot be reused in conjunction with the main project, which is a waste. Therefore, a fully prefabricated, repeatedly pluggable, and pile-row foundation pit support structure that can be used as a bearing pile foundation in the main project was invented. Utility Model Content

[0004] In view of the shortcomings of existing pile-type projects with large investment, which often cannot be reused as the main project and have poor economic efficiency, the utility model proposes a reusable single-row pile foundation pit support structure. It can not only meet the stability of the support structure, but also has fast construction. The pile foundation can be pulled out and reused as the support structure or the main structure foundation. The rear row of water-stop curtains adopts high-pressure jet piles between piles, and the pile head can be impact drilled. It can be applied to hard and complex geological structures such as block stones and floating stones, and has strong adaptability. At the same time, the skip pile hole forming process is adopted, the number of pile foundation roots is small, the project efficiency is improved, and the project investment is saved.

[0005] To achieve the above purpose, the utility model is implemented through the following technical solutions:

[0006] A pluggable foundation pit support structure based on prefabricated components, comprising a plurality of hollow prefabricated pipe piles arranged side by side and at intervals in a foundation pit, grouting holes being reserved inside the hollow prefabricated pipe piles, a water-stop curtain being arranged in the foundation pit between two adjacent hollow prefabricated pipe piles, a seal being formed between the water-stop curtain and the adjacent hollow prefabricated pipe piles, a prefabricated crown beam being arranged on the top of the hollow prefabricated pipe pile, and a support being arranged laterally on the inner side of the prefabricated crown beam.

[0007] Preferably, the prefabricated crown beam is formed by at least two prefabricated crown beam units spliced ​​in half by tension bolts, and the two prefabricated crown beam units are enclosed to form a pile guide hole for installing the hollow prefabricated pipe pile.

[0008] Preferably, the prefabricated crown beam adopts a prefabricated concrete structure.

[0009] Preferably, the hollow prefabricated pipe piles adopt a high-strength concrete structure with a strength of C50 or above.

[0010] Preferably, the water-stop curtain adopts a high-pressure jet-jet pile structure.

[0011] Preferably, a lifting ring is provided on the top of the hollow prefabricated pipe pile.

[0012] Preferably, the support is a steel pipe support or a reinforced concrete support.

[0013] Compared with the prior art, the utility model has the following significant advantages:

[0014] 1. The utility model adopts prefabricated structures for the foundation pit support structure through hollow prefabricated pipe piles, prefabricated crown beams, tension high-strength bolts, and prefabricated steel pipe supports, and has the characteristics of fast construction speed, repeated plugging and unplugging, and high recycling.

[0015] 2. The utility model adopts a prestressed high-strength prefabricated pipe pile structure, and a prefabricated lifting ring is used on the top of the pipe pile to achieve the removal after the pile is formed. The pipe pile has the characteristics of high bearing capacity and can be used as the main engineering bearing pile, which is economical. The pile body can be spliced ​​and has a high reuse rate.

[0016] 3. The utility model adopts a high-pressure rotary jet pile structure between piles and uses skip pile drilling to save engineering investment. At the same time, the high-pressure rotary jet pile can use an impact drill bit to drill through hard foundation soil such as blocks of stone and boulders, and has strong geological adaptability.

[0017] 4. Grouting holes are reserved between the pipe piles of the utility model. After the interior of the pile body is backfilled with medium-coarse sand, cement slurry is injected into the pile body by the post-grouting process to ensure the internal density of the pile body and a certain pile end bearing capacity.

[0018] 5. All structures of the utility model, such as the pluggable single-row pile foundation pit supporting structure, can be prefabricated, with fast construction and little pollution, meeting the needs of sustainable development of prefabrication and assembly of water conservancy projects; while ensuring stable and safe foundation pit construction, its high-strength prefabricated pipe piles can be repeatedly plugged and pulled out for use, while taking into account the main structure, as a bearing pile foundation, achieving the characteristic of saving project investment to the greatest extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic cross-sectional view of the overall structure of an embodiment of the utility model;

[0020] Figure 2 It is a schematic plan view of the overall structure of an embodiment of the utility model;

[0021] Figure 3 yes Figure 1 A partial enlarged structural diagram of the middle foundation pit support structure;

[0022] Figure 4 This is a layout diagram of the hollow prefabricated pipe piles and the water-stop curtain of the embodiment of the utility model;

[0023] Figure 5 It is a schematic diagram of the prefabricated crown beam splicing structure of an embodiment of the utility model.

[0024] In the figure: 1. Soil outside the foundation pit; 2. Water-stop curtain; 3. Lifting ring; 4. Grouting hole; 5. Hollow prefabricated pipe pile; 6. Prefabricated crown beam; 6.1. Prefabricated crown beam unit; 6.2. Pile guide hole; 7. Support; 8. Soil inside the foundation pit; 9. Tension bolts. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solution of the utility model, the preferred implementation scheme of the utility model is described below in conjunction with specific embodiments, but it should be understood that the drawings are only for illustrative purposes and cannot be understood as limiting the utility model; in order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, the omission of some well-known structures and their descriptions in the drawings is understandable. The positional relationship described in the drawings is only for illustrative purposes and cannot be understood as limiting the utility model.

[0026] like Figure 1-5 As shown, the utility model is a pluggable foundation pit support structure based on prefabricated components, including hollow prefabricated pipe piles 5, grouting holes 4, water-stop curtains 2, prefabricated crown beams 6 and supports 7.

[0027] The main support structure adopts hollow prefabricated pipe piles 5, and the pile structure adopts high-strength concrete structure with strength of C50 or above. The center of the pile body is a hollow structure with strong compression and bending resistance, which can meet the pile hammering strength of pile foundation construction. At the same time, it has great bending and shearing resistance, meeting the structural strength requirements of foundation pit support. After the pre-supported pipe piles are hammered or statically pressed into piles, the center of the pile body is backfilled with coarse sand and then cement slurry is injected through a grouting pipe to ensure the compressive strength and bending and shearing resistance of the pile body.

[0028] like Figure 4As shown, when the hollow prefabricated pipe pile 5 is prefabricated on the pile top, four symmetrical lifting rings 3 for pulling out are installed. After the foundation pit structure is completed, the lifting rings 3 can be pulled out by a lifting machine. The lifting rings 3 have strong tensile strength. The hollow prefabricated pipe pile 5 can be pulled out and then driven into a pile. Unlike conventional support pile foundations that are not recycled, this support pile can be reused and has a high vertical bearing capacity. Finally, it can be used as the foundation pile foundation of the main structure. It has strong engineering adaptability and greatly reduces engineering investment.

[0029] like Figure 2 and 4 As shown, the pile row after the foundation pit support adopts a water-stop curtain 2 of a high-pressure rotary jet pile structure. The water-stop curtain 2 adopts a skip-hole pile-forming process and is arranged between the gaps of prefabricated pipe piles, which reduces the number of water-stop curtain 2 piles and saves project investment. The high-pressure rotary jet pile structure has the characteristics of small drilling holes, high injection pressure, and good water-stopping effect. At the same time, an impact drill bit can be used during the construction of the water-stop pile, which can overcome the problem that the conventional mixing pile water-stop curtain 2 cannot be constructed when encountering block stones, and can adapt to hard and complex geological conditions such as block stones and boulders, and has strong adaptability.

[0030] like Figure 5 As shown, the prefabricated crown beam 6 adopts a prefabricated concrete structure. The prefabricated crown beam 6 is composed of at least two prefabricated crown beam units 6.1 spliced ​​in half by tension bolts 9, and spliced ​​in sections to form an integral crown beam. The two prefabricated crown beam units 6.1 are enclosed to form a pile guide hole 6.2 for installing the hollow prefabricated pipe pile 5. Before the hammering construction of the prefabricated pipe pile, the crown beam can be simply spliced ​​in advance as the pile guide hole 6.2 of the pile foundation. After the hammering pile is completed, the tension bolts 9 are tightened to connect firmly. The tension bolts 9 are made of high-strength steel bolts, with two on each connection surface. The crown beam structure adopts a splicing process. After the foundation pit construction is completed, it can be dismantled and reused in the next section of the foundation pit. A welded steel plate can be reserved on the side to facilitate the support 7 welding construction.

[0031] like Figure 1-3 As shown, the support 7 can be a steel pipe support or a reinforced concrete support. The steel pipe support has the characteristics of fast construction speed and high dismantling and reuse rate. The reinforced concrete support has the characteristics of high compressive strength, and can be used to construct different supports 7 in conjunction with the steel plates or steel bars reserved on the side of the prefabricated crown beam 6.

[0032] Construction of foundation pit support structure:

[0033] When constructing the support structure, the prefabricated crown beam 6 is first spliced ​​according to the construction layout. When splicing, the tension bolts 9 should be simply connected so that a certain gap is left in the circular holes between the crown beams to facilitate the pile formation. The crown beam serves as a pile guide hole 6.2 on the one hand to control the horizontal deviation of the pile body and ensure that the pile center is in a straight line. On the other hand, the various piles are connected into a whole with overall rigidity. In order to ensure the lateral compressive strength of the pile body, coarse sand can be backfilled in the pile body, and then cement slurry can be backfilled in the grouting hole 4 to ensure the compactness of the pile body.

[0034] Furthermore, during the construction of the hollow prefabricated pipe pile 5, the pile can be formed by hammering or static pressure. After the pile is sunk, the tension bolts 9 are tightened to form an integral crown beam, and the bolts can be removed and reused later.

[0035] Furthermore, a water-stop curtain 2 is constructed to seal the soil between the pipe piles, so that the soil and water inside and outside the foundation pit can flow mutually. High-pressure jet grouting piles can be drilled with an impact drill, and the pile body can penetrate hard geological structures such as block stones, and has strong adaptability.

[0036] Furthermore, the inner support 7 of the crown beam is constructed, and the support 7 is supported by a hollow steel pipe, which is welded on the crown beam and forms a supporting structure with the opposite row of piles. The support 7 has the characteristics of fast construction speed and high recycling rate in the later stage, and meets the strength, safety and economic requirements of the foundation pit support 7.

[0037] After the construction of the above-mentioned support structure is completed, the foundation pit soil can be excavated to the designed elevation. Finally, the structure inside the foundation pit is constructed. After the structure inside the foundation pit is completed, the top support 7 of the crown beam is removed, the tension bolts 9 are removed, and the prefabricated crown beam 6 is removed. Finally, the hollow prefabricated pipe pile 5 is pulled out and used for the next section of the foundation pit using the lifting ring 3 at the top. Alternatively, the hollow prefabricated pipe pile 5 has the characteristics of large vertical bearing capacity according to the support pile row. After being pulled out, it can be used as the pile foundation of the main structure of the sluice, pump station, and building house, which saves the project investment to the maximum extent.

[0038] According to the description and drawings of the utility model, those skilled in the art can easily manufacture or use the pluggable foundation pit support structure based on prefabricated components of the utility model, and can produce the positive effects recorded in the utility model.

[0039] Unless otherwise specified, in the present invention, the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicating orientation or positional relationships are based on the orientation or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the orientation or positional relationships in the present invention are only used for illustrative purposes and cannot be understood as limitations on the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood in conjunction with the accompanying drawings and according to specific circumstances.

[0040] Unless otherwise specified and limited, in the present invention, the terms "disposed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or 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.

[0041] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A pluggable foundation pit support structure based on prefabricated components, characterized in that: The invention comprises a plurality of hollow prefabricated pipe piles (5) arranged side by side and at intervals in a foundation pit, wherein a grouting hole (4) is reserved inside the hollow prefabricated pipe piles (5), a water-stop curtain (2) is arranged in the foundation pit between two adjacent hollow prefabricated pipe piles (5), a seal is formed between the water-stop curtain (2) and the adjacent hollow prefabricated pipe piles (5), a prefabricated crown beam (6) is arranged on the top of the hollow prefabricated pipe pile (5), and a support (7) is arranged laterally inside the prefabricated crown beam (6).

2. The pluggable foundation pit support structure based on prefabricated components according to claim 1 is characterized in that: The prefabricated crown beam (6) is formed by at least two prefabricated crown beam units (6.1) being spliced ​​in half by tension bolts (9), and the two prefabricated crown beam units (6.1) are enclosed to form a pile guide hole (6.2) for installing the hollow prefabricated pipe pile (5).

3. The pluggable foundation pit support structure based on prefabricated components according to claim 1 or 2, characterized in that: The prefabricated crown beam (6) adopts a prefabricated concrete structure.

4. The pluggable foundation pit support structure based on prefabricated components according to claim 1 is characterized in that: The hollow prefabricated pipe pile (5) adopts a high-strength concrete structure with a strength of C50 or above.

5. The pluggable foundation pit support structure based on prefabricated components according to claim 1 is characterized in that: The water-stop curtain (2) adopts a high-pressure jet-jet pile structure.

6. The pluggable foundation pit support structure based on prefabricated components according to claim 1 is characterized in that: The top of the hollow prefabricated pipe pile (5) is provided with a lifting ring (3).

7. The pluggable foundation pit support structure based on prefabricated components according to claim 1 is characterized in that: The support (7) is a steel pipe support or a reinforced concrete support.

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