A reinforcement structure and construction method for soft soil foundation after failure of anti-floating piles

Abstract

The present invention discloses a reinforcement structure and construction method for anti-floating piles in soft soil after their failure, belonging to the technical field of anti-floating pile reinforcement. Reinforcement bodies are uniformly arranged circumferentially around the original anti-floating piles to form an embraced reinforced anti-floating pile structure. The reinforcement bodies include an enlarged head anchor pile and a grouting body formed by high-pressure grouting flower pipe grouting to connect the original anti-floating pile and the enlarged head anchor rod. The enlarged head anchor rod is provided with a steel strand that runs through the enlarged head anchor rod, and special anchors are provided at the top and bottom of the steel strand to fix it. An enlarged head anchor rod mounting hole is opened in the original waterproof board, and the top of the enlarged head anchor pile is installed in conjunction with the original waterproof board, and a new waterproof board is provided above the enlarged head anchor rod and the original waterproof board. The special anchor at the top of the steel strand is sealed and protected by concrete and cast integrally with the new waterproof board. The present invention can effectively increase the soil friction resistance between piles, increase the friction resistance area, and greatly improve the anti-buoyancy of the reinforced anti-floating piles.

Description

Technical Field

[0001] The invention relates to the technical field of anti-floating pile reinforcement, in particular to a reinforcement structure and a construction method for soft soil foundation anti-floating piles after failure. Background Art

[0002] In recent years, due to an increase in extreme weather, rainfall in some areas has reached levels not seen in 50 or even 100 years. The actual groundwater level in some garages is higher than the anti-floating design water level, or precipitation measures are not in place during construction. The safety factor of the anti-floating piles in the soft soil foundation is too low, resulting in overall anti-floating of the garage and the pullout of the anti-floating piles. Currently, the main methods for solving the overall floating of garages include installing anti-floating anchor rods and adding counterweights. Installing anti-floating anchor rods alone requires a large number and is uneconomical. Adding counterweights to the waterproof base plate affects the structural height, and adding counterweights to the garage roof plate can easily lead to insufficient bearing capacity of the beams and slabs. Therefore, restoring the original anti-floating piles' anti-floating force is particularly important. Summary of the Invention

[0003] The technical task of the present invention is to address the above shortcomings and provide a reinforcement structure and construction method for anti-floating piles in soft soil foundation after failure, which can effectively increase the deadweight of anti-floating piles, improve the soil friction resistance between piles, increase the friction resistance area, and effectively prevent pile body fracture.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A reinforcement structure for soft soil foundation anti-floating piles after failure, in which reinforcement bodies are evenly arranged around the original anti-floating piles to form an embrace-type reinforcement anti-floating pile structure;

[0006] The reinforcement body includes an enlarged head anchor pile and a grouting body connecting the original anti-floating pile and the enlarged head anchor pile formed by grouting with a high-pressure grouting flower pipe.

[0007] The enlarged head anchor pile is provided with a steel strand that passes through the enlarged head anchor pile, and special anchors are provided at the top and bottom ends of the steel strand to fix them;

[0008] An enlarged head anchor pile installation hole is opened on the original waterproof board, and the top of the enlarged head anchor pile is installed in conjunction with the original waterproof board, and a new waterproof board is arranged above the enlarged head anchor pile and the original waterproof board, and a drainage board is arranged between the new waterproof board and the original waterproof board; the original waterproof board at the top of the enlarged head anchor pile is subjected to concrete chiseling and grouting filling, and a top waterstop steel plate is arranged at the top of the enlarged head anchor pile, and the top surface of the top waterstop steel plate is flush with the upper surface of the original waterproof board; the steel strand passes upward through the top waterstop steel plate and is fixed above the top waterstop steel plate by a special anchor; the special anchor at the top of the steel strand is sealed and protected with concrete and cast as a whole with the new waterproof board.

[0009] There are two main reasons for the pullout of anti-floating piles: pile fracture and pile friction loss. This structure overcomes the friction loss problem by installing enlarged-head anti-floating anchors around the original anti-floating piles. High-pressure grouting pipes are placed between the enlarged-head anti-floating anchors and the original anti-floating piles. High-pressure grouting forms a grouting body connecting the original anti-floating piles and the enlarged-head anchors, effectively overcoming this. The enlarged-head anchors provide frictional resistance, while the soil at the front of the enlarged-head anchors provides resistance. After the grout in the enlarged-head anchors initially sets, the grouting pipes between the original anti-floating piles and the enlarged-head anchors re-compact the loose soil around the piles through pressure grouting, increasing inter-pile friction. The newly added enlarged-head anti-floating anchors embrace the original piles to form a monolithic structure, increasing the frictional area and the deadweight of the anti-floating piles. Pre-embedded steel strands within the enlarged-head anchors provide tensile strength, addressing the problem of pile fracture. Therefore, the structure can effectively solve the problems of anti-floating pile body fracture and anti-floating pile body friction resistance failure.

[0010] Preferably, the number of reinforcement bodies uniformly arranged circumferentially of the original anti-floating pile is 3, forming a stable triangular structure.

[0011] Preferably, the high-pressure grouting flower pipe is arranged in the enlarged head anchor pile, close to the side of the original anti-floating pile. The high-pressure grouting flower pipe can be pre-placed in the enlarged head anchor pile for integral processing, thereby simplifying the construction process and improving construction efficiency.

[0012] Furthermore, the enlarged head anchor pile is divided into a lower enlarged head section and an upper common anchoring section, and the high-pressure grouting flower pipe is arranged in the common anchoring section.

[0013] Preferably, the high-pressure grouting flower pipe is arranged on the outside of the enlarged head anchor pile on the side closest to the original anti-floating pile. The high-pressure grouting flower pipe is located between the enlarged head anchor pile and the original anti-floating pile, or can be located directly adjacent to the enlarged head anchor pile. After high-pressure grouting, the enlarged head anchor pile and the original anti-floating pile are firmly fixed.

[0014] Preferably, the steel strand consists of three strands.

[0015] Preferably, the bottom end of the steel strand is fixed in the bottom of the enlarged head anchor pile by a special anchor, and a bottom water-stop steel plate is provided. The bottom end of the steel strand passes downward through the bottom water-stop steel plate and is fixed by the special anchor.

[0016] The present invention also claims protection for a method for constructing a reinforcement structure after the failure of anti-floating piles on a soft soil foundation. The method constructs the reinforcement structure after the failure of the anti-floating piles on the soft soil foundation, and performs grouting construction of a high-pressure grouting flower pipe when the cement slurry has initially set after the construction of the enlarged head anchor piles.

[0017] During the high-pressure grouting construction of the flower pipe, the grouting should be carried out while lifting. The depth of the first grouting hole should not be less than 15m, and grouting should be carried out once every 3m of lifting height.

[0018] Preferably, the high-pressure grouting flower pipe grouting adopts ordinary 425# silicate cement, and the water-cement ratio of the cement slurry is 0.6-0.8; the external admixture of water glass is 5% of the cement admixture.

[0019] Preferably, the diameter of a single grouting body formed after grouting the high-pressure grouting flower tube is not less than 1.0 m.

[0020] Compared with the prior art, the reinforcement structure and construction method of the present invention for soft soil foundation after failure of anti-floating piles have the following beneficial effects:

[0021] In this structure, the enlarged-head anchor pile provides frictional resistance to the pile body, while the soil at the front of the enlarged head provides resistance to the enlarged head. After the slurry in the enlarged-head anchor pile body initially sets, the high-pressure grouting pipe installed between the original anti-floating pile and the enlarged-head anchor cable re-compacts the loose soil around the pile body through pressure grouting, thereby increasing the frictional resistance between the piles. At the same time, the newly added anti-floating anchor rods surround the original pile body to form an integral structure, increasing the frictional resistance area and the deadweight of the anti-floating pile. At the same time, the pre-embedded steel strands in the enlarged-head anchor pile provide tension, solving the problem of pile body fracture. This structure is simple, the construction method is easy to operate, and it is both economical and efficient, with good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram of a structure of an anti-floating pile with an embrace type reinforcement for a soft soil foundation after the anti-floating pile fails, provided by an embodiment of the present invention;

[0023] Figure 2 This is a cross-sectional structural diagram of an enlarged head anchor pile, a reinforcement structure for a soft soil foundation after failure of an anti-floating pile provided by an embodiment of the present invention;

[0024] Figure 3 yes Figure 2 A partial enlarged view of ① in the middle;

[0025] Figure 4 yes Figure 2 A partial enlarged view of ② in the middle;

[0026] Figure 5 yes Figure 2 Cross-section of the middle AA;

[0027] Figure 6 This is a diagram of another type of reinforcing anti-floating pile structure for soft soil foundation after the anti-floating pile fails, provided by an embodiment of the present invention.

[0028] In the figure, 1. Original anti-floating pile, 2. Enlarged head anchor pile, 3. High-pressure grouting flower pipe, 4. Grouting body, 5. Enlarged head section, 6. Ordinary anchor section, 7. Steel strand, 8. Original waterproof board, 9. Newly added waterproof board, 10. Drain board, 11. Special anchor, 12. Top waterstop steel plate, 13. Concrete removal and grouting material filling, 14. Bottom waterstop steel plate, 15. Cement slurry. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] The embodiment of the present invention provides a reinforcement structure for anti-floating piles in soft soil after failure, wherein reinforcement bodies are evenly arranged around the original anti-floating piles 1 to form a hugging reinforcement anti-floating pile structure. Figure 1 As shown, in this embodiment, three reinforcement bodies are used to form a stable triangular structure.

[0031] The reinforcement body includes an enlarged head anchor pile 2 and a grouting body 4 connecting the original anti-floating pile 1 and the enlarged head anchor pile 2 formed by grouting construction with a high-pressure grouting flower pipe 3.

[0032] like Figure 2 As shown, the enlarged head anchor pile 2 is provided with a steel strand 7 running through the enlarged head anchor pile 2, and special anchors 11 are respectively provided at the top and bottom ends of the steel strand 7 to fix them.

[0033] The high-pressure grouting tube 3 is installed inside the enlarged-head anchor pile 2, near the original anti-floating pile 1. The enlarged-head anchor pile 2 is divided into a lower enlarged-head section 5 and an upper conventional anchoring section 6. The high-pressure grouting tube 3 is installed in the conventional anchoring section 6. The high-pressure grouting tube 3 can be pre-installed inside the enlarged-head anchor pile 2 as an integral part of the process, simplifying the construction process and improving efficiency.

[0034] In this embodiment, the length of the enlarged head anchor pile 2 is greater than 18m, wherein the enlarged head section is ≥4m; the diameter of the enlarged head section 5 is 600mm, the diameter of the ordinary anchoring section 6 is 200mm, and three bundles of φ15.2 steel strands are used.

[0035] like Figure 3 As shown, an enlarged head anchor pile installation hole is opened in the original waterproofing board 8. The top of the enlarged head anchor pile 2 is installed in conjunction with the original waterproofing board 8. A new waterproofing board 9 is installed above the enlarged head anchor pile 2 and the original waterproofing board 8, and a drainage board 10 is installed between the new waterproofing board 9 and the original waterproofing board 8. The original waterproofing board 8 at the top of the enlarged head anchor pile 2 is concreted out and filled with grouting material. A top waterstop steel plate 12 is installed at the top of the enlarged head anchor pile 2. The top surface of the top waterstop steel plate 12 is flush with the upper surface of the original waterproofing board 8. The top waterstop steel plate 12 is a square steel plate and is coated with a cement-based waterproof crystalline material.

[0036] The steel strand 7 passes upward through the top water-stop steel plate 12 and is fixed above the top water-stop steel plate 12 by a special anchor 11. The special anchor 11 at the top of the steel strand 7 is sealed and protected by concrete and cast integrally with the newly added waterproof plate 9.

[0037] like Figure 4 As shown, the bottom end of the steel strand 7 is fixed inside the bottom of the enlarged head anchor pile 2 by a special anchor 11, and a bottom water-stop steel plate 13 is provided. The bottom water-stop steel plate 13 is a circular steel plate coated with anti-corrosion material. The bottom end of the steel strand 7 passes downward through the bottom water-stop steel plate 13 and is fixed by a special anchor 11.

[0038] For the reinforcement structure of a soft soil foundation after the failure of the anti-floating pile described in the above embodiment, the embodiment of the present invention also provides its construction method, which constructs the reinforcement structure of the soft soil foundation after the failure of the anti-floating pile, and performs grouting construction of the high-pressure grouting flower pipe 3 when the cement slurry is initially set after the construction of the enlarged head anchor pile 2; a φ32×3 flower pipe is used to adhere to the pipe wall for pressure grouting.

[0039] During the grouting construction of the high-pressure grouting flower pipe 3, the grouting should be carried out while lifting. The depth of the first grouting hole should not be less than 15m, and grouting should be carried out once every 3m of lifting height.

[0040] High-pressure grouting flower pipe grouting uses ordinary 425# silicate cement, and the water-cement ratio (weight ratio) of the cement slurry is 0.6-0.8; the external admixture of water glass is 5% of the cement admixture (weight ratio).

[0041] The diameter of a single grouting body 4 formed after grouting the high-pressure grouting flower tube 3 is not less than 1.0 m.

[0042] The grouting flow rate can be 7-10L / min.

[0043] During construction, the groundwater level should be lowered to 500mm below the working surface. The strength grade of the cement soil mass at the expanded head should be no less than 15MPa.

[0044] To address the two main issues associated with pulling out anti-floating piles: pile fracture and frictional failure, this design overcomes this frictional failure by installing enlarged-head anti-floating anchors around the original anti-floating piles. High-pressure grouting pipes are placed between the enlarged-head anti-floating anchors and the original anti-floating piles. High-pressure grouting forms a grouting body connecting the original anti-floating piles and the enlarged-head anchors, effectively overcoming this frictional failure. The enlarged-head anchors provide frictional resistance, while the soil at the front of the enlarged-head anchors provides resistance. After the initial setting of the grout in the enlarged-head anchors, the grouting pipes between the original anti-floating piles and the enlarged-head anchors re-compact the loose soil around the piles through pressure grouting, increasing the frictional resistance between the piles. The newly added enlarged-head anti-floating anchors embrace the original piles to form a monolithic structure, increasing the frictional area and the deadweight of the anti-floating piles. Pre-embedded steel strands within the enlarged-head anchors provide tensile strength, addressing the issue of pile fracture. Therefore, the structure can effectively solve the problems of anti-floating pile body fracture and anti-floating pile body friction resistance failure.

[0045] The scope of application of this method for soft soil does not include organic soil, silt or silty soil. This method compacts the soil through post-grouting, which can effectively increase the friction resistance of the soil between piles. Reinforcement bodies are evenly arranged circumferentially around the original anti-floating piles to form an embracing reinforced anti-floating pile structure, which can effectively increase the friction area, thereby greatly improving the anti-floating force of the reinforced anti-floating piles.

[0046] The embodiment of the present invention also provides another reinforcement structure for anti-floating piles on soft soil foundation after failure, in which reinforcement bodies are evenly arranged circumferentially around the original anti-floating pile 1 to form an embrace-type reinforcement anti-floating pile structure. In this embodiment, the high-pressure grouting flower pipe 3 is arranged on the outside of the enlarged head anchor pile 2 on the side close to the original anti-floating pile 1. The high-pressure grouting flower pipe 3 is located between the enlarged head anchor pile 2 and the original anti-floating pile 1, and can also be close to the enlarged head anchor pile 2. After high-pressure grouting, the enlarged head anchor pile 2 is firmly fixed to the original anti-floating pile 1. Its structural diagram is shown in the figure below. Figure 6 shown.

[0047] The construction of this structure can refer to the construction method in the above embodiment. The remaining matters are existing construction processes and will not be described in detail.

[0048] The above specific embodiments will allow those skilled in the art to easily implement the present invention. However, it should be understood that the present invention is not limited to the above specific embodiments. Based on the disclosed embodiments, those skilled in the art can arbitrarily combine different technical features to implement different technical solutions.

[0049] Except for the technical features described in the specification, all other technical features are known technologies to those skilled in the art.

Claims

1. A reinforcement structure for soft soil foundation after the failure of anti-floating piles, characterized by Arrange reinforcement bodies evenly around the original anti-floating piles to form an embracing reinforced anti-floating pile structure; The reinforcement body includes an enlarged head anchor pile and a grouting body connecting the original anti-floating pile and the enlarged head anchor pile formed by grouting with a high-pressure grouting flower pipe. The enlarged head anchor pile is provided with a steel strand that passes through the enlarged head anchor pile, and special anchors are provided at the top and bottom ends of the steel strand to fix them; An enlarged head anchor pile installation hole is opened on the original waterproof board, and the top of the enlarged head anchor pile is installed in conjunction with the original waterproof board, and a new waterproof board is arranged above the enlarged head anchor pile and the original waterproof board, and a drainage board is arranged between the new waterproof board and the original waterproof board; the original waterproof board at the top of the enlarged head anchor pile is concreted out and filled with grouting material, and a top waterstop steel plate is arranged on the top of the enlarged head anchor pile, and the top surface of the top waterstop steel plate is flush with the upper surface of the original waterproof board; the steel strand passes upward through the top waterstop steel plate and is fixed above the top waterstop steel plate by a special anchor; the special anchor at the top of the steel strand is sealed and protected with concrete and cast as a whole with the new waterproof board; The high-pressure grouting flower pipe is arranged in the enlarged head anchor pile, close to the side of the original anti-floating pile; The enlarged head anchor pile is divided into a lower enlarged head section and an upper common anchor section, and the high-pressure grouting flower pipe is arranged in the common anchor section; and the high-pressure grouting flower pipe is arranged on the outer side of the enlarged head anchor pile close to the original anti-floating pile; The bottom end of the steel strand is fixed in the bottom of the enlarged head anchor pile by a special anchor, and a bottom water-stop steel plate is provided. The bottom end of the steel strand passes through the bottom water-stop steel plate and is fixed by the special anchor.

2. The reinforcement structure for soft soil foundation after failure of anti-floating piles according to claim 1 is characterized in that The number of reinforcement bodies evenly arranged around the circumference of the original anti-floating piles was 3.

3. The reinforcement structure for soft soil foundation after failure of anti-floating piles according to claim 1 is characterized in that The steel strand consists of three strands.

4. A construction method for reinforcing a soft soil foundation after the failure of anti-floating piles, characterized in that The reinforcement structure after failure of the anti-floating piles on the soft soil foundation according to any one of claims 1 to 3 is constructed, and the grouting construction of the high-pressure grouting flower pipe is carried out when the cement slurry is initially set after the construction of the enlarged head anchor pile is completed; During the high-pressure grouting construction of the flower pipe, the grouting should be carried out while lifting. The depth of the first grouting hole should not be less than 15m, and grouting should be carried out once every 3m of lifting height.

5. The method for reinforcing a soft soil foundation after failure of anti-floating piles according to claim 4 is characterized in that High-pressure grouting flower pipe grouting uses ordinary 425# silicate cement, and the water-cement ratio of the cement slurry is 0.6-0.8; the external admixture of water glass is 5% of the cement admixture.

6. The method for reinforcing a soft soil foundation after failure of anti-floating piles according to claim 4 or 5, characterized in that The diameter of a single grouting body formed after grouting of the high-pressure grouting flower tube shall not be less than 1.0m.

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