Miniature steel pipe pile
By applying prestress to the micro-steel pipe pile structure and connecting it with the grouting body, the problem of poor slope reinforcement effect is solved, and rapid and safe reinforcement in special sections is achieved, which is particularly suitable for emergency rescue projects.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA RAILWAY ECONOMIC & PLANNING RES INST
- Filing Date
- 2025-05-14
- Publication Date
- 2026-07-03
AI Technical Summary
Existing slope reinforcement methods are less effective in loose strata, areas with abundant groundwater, areas near existing buildings, and areas with limited terrain. They also cause significant construction disturbance and are difficult to meet the requirements for rapid and safe construction.
The micro steel pipe pile structure includes stainless steel grouting pipes, pads, and anchor nuts. Prestress is applied by tightening the anchor nuts. Combined with the internal stiffeners and grouting body, a prestressed steel pipe pile is formed, which enhances the shear resistance. The grouting body connects with the soil to improve the strength of the soil layer around the pile.
It enables slope stability reinforcement in special locations, improves the reinforcement effect, and meets the requirements of rapid and safe construction, making it particularly suitable for emergency rescue projects.
Smart Images
Figure CN224451670U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of slope construction technology, specifically a miniature steel pipe pile. Background Technology
[0002] In slope construction for railways and highways in mountainous areas, problems such as landslides, collapses, and roadbed instability and deformation are frequently encountered. Prestressed anchor cables, anti-slide piles, and micropiles are widely used in the treatment of these problems. However, these reinforcement measures have certain drawbacks under some conditions. For example, prestressed anchor cables have poor shear resistance, and the construction of anti-slide piles causes significant disturbance, especially in loose strata and areas with abundant groundwater, where pile excavation carries high risks. In areas near existing railway lines or with steep terrain, bored piles are not feasible. Conventional micropiles only passively reinforce the soil and cannot implement prestressing, resulting in poor reinforcement effects. Utility Model Content
[0003] To address the issue of poor reinforcement effects in existing slope reinforcement methods, this invention provides a miniature steel pipe pile. This miniature steel pipe pile can be prestressed, effectively solving landslide and slope stability reinforcement problems in special locations such as loose strata, areas with abundant groundwater, adjacent to existing buildings, and terrain-constrained areas. Furthermore, while improving reinforcement effectiveness, it also meets the requirements for rapid and safe construction.
[0004] The technical solution adopted by this utility model embodiment to solve its technical problem is:
[0005] A miniature steel pipe pile includes a stainless steel grouting pipe, a pad, and an anchor nut. Along the direction from the inner end to the outer end of the stainless steel grouting pipe, the pipe wall contains sequentially arranged grouting pipe sections and connecting pipe sections. Multiple grouting through holes are provided on the wall of each grouting pipe section. External threads are provided on the outer circumferential surface of the connecting pipe section. The pad and anchor nut are both fitted onto the outside of the stainless steel grouting pipe. The anchor nut is threadedly connected to the connecting pipe section, with its inner end face facing the inner end of the stainless steel grouting pipe. The inner end face of the anchor nut abuts against the outer end face of the pad.
[0006] The outer diameter of the stainless steel grouting pipe is 100mm to 300mm, the wall thickness is 8mm to 10mm, the inner end of the stainless steel grouting pipe is either closed or open, and the outer end of the stainless steel grouting pipe is open.
[0007] The length of the grouting pipe section is 70% to 90% of the length of the stainless steel grouting pipe, and multiple grouting through holes are arranged in regular rows on the pipe wall of the grouting pipe section.
[0008] The stainless steel grouting pipe is equipped with a grouting body. Along the direction from the inner end of the stainless steel grouting pipe to the outer end, the grouting body contains a first grouting material inner section and a second grouting material inner section arranged sequentially.
[0009] Both the inner sections of the first and second grouting materials are made of hardened cement mortar, and a grout stopper is installed between the inner sections of the first and second grouting materials.
[0010] The stainless steel grouting pipe is fitted with a stiffener, which has a columnar structure, and an annular cavity is formed between the stainless steel grouting pipe and the stiffener.
[0011] The stiffening body contains multiple threaded steel bars arranged side by side, which are welded and fixed together. The axis of the threaded steel bars is parallel to the axis of the stainless steel grouting pipe.
[0012] The pad is made of stainless steel. The inner diameter of the pad is smaller than the outer diameter of the anchor nut, while the outer diameter of the pad is larger than the outer diameter of the anchor nut.
[0013] The micro steel pipe pile also includes a centering pad, which has a wedge-shaped structure and is also fitted over the stainless steel grouting pipe. When the micro steel pipe pile is installed on the slope, the stainless steel grouting pipe is in a horizontal state, with the inner end of the stainless steel grouting pipe located inside the slope, and the outer end of the stainless steel grouting pipe, the pad, and the anchor nut all located outside the slope surface. The outer end face of the centering pad matches and abuts against the inner end face of the pad, and the inner end face of the centering pad matches and abuts against the slope surface. After tightening the anchor nut, the stainless steel grouting pipe can be subjected to tensile force.
[0014] The material of the centering pad is reinforced concrete.
[0015] The beneficial effects of this utility model embodiment are: by tightening the anchor nut, the prestress of the steel pipe pile is applied, and at the same time, the shear resistance of the steel pipe pile is greatly improved by the reinforcement inside the pipe. This structure has the advantages of both anchor cable and micro steel pipe pile, and is easy to construct. It can be used in reinforcement projects where the environment and time are limited, and is especially suitable for emergency rescue projects. Attached Figure Description
[0016] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.
[0017] Figure 1 This is a schematic diagram of the usage state of the miniature steel pipe pile described in this utility model.
[0018] Figure 2 This is a cross-sectional schematic diagram of the miniature steel pipe pile described in this utility model.
[0019] Figure 3 This is an external schematic diagram of a stainless steel grouting pipe.
[0020] Figure 4 This is a schematic diagram of the interior of a stainless steel grouting pipe.
[0021] The annotations in the attached figures are explained as follows:
[0022] 1. Stainless steel grouting pipe; 2. Reinforcing body; 3. Grout stop plug; 4. Grouting body; 5. Pad plate; 6. Rotation pad; 7. Anchor nut; 8. Slope;
[0023] 11. Grouting pipe section; 12. Connecting pipe section; 13. Grouting through hole; 14. External thread;
[0024] 21. Rebar;
[0025] 41. Grout the inner section first; 42. Grout the inner section later;
[0026] 81. Slope. Detailed Implementation
[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0028] For ease of understanding and description, the following description of this utility model uses absolute positional relationships. Unless otherwise specified, the directional word "above" indicates... Figure 1 The direction above, the directional word "down" indicates Figure 1 The lower side of the middle, "left" indicates Figure 1 The left side of the direction, the directional word "right" indicates Figure 1 The right-hand direction in the middle, "front" means perpendicular to Figure 1 The direction of the paper and the direction pointing inwards; the directional word "back" indicates perpendicular to. Figure 1 The orientation of the paper is pointed outwards from the viewpoint of the reader or user. This invention is described from the perspective of the reader or user, but the aforementioned directional terms should not be construed as limiting the scope of protection of this invention. Regarding the dimensions and angles of the components, those skilled in the art can determine them specifically based on actual needs or a limited number of experiments.
[0029] like Figure 1As shown in the embodiment of this utility model, a miniature steel pipe pile includes a stainless steel grouting pipe 1, a pad 5, and an anchor nut 7. Along the direction from the inner end to the outer end of the stainless steel grouting pipe 1, the pipe wall of the stainless steel grouting pipe 1 contains grouting pipe sections 11 and connecting pipe sections 12 arranged sequentially. The pipe wall of the grouting pipe section 11 is provided with multiple grouting through holes 13. The outer circumferential surface of the connecting pipe section 12 is provided with external threads 14. The pad 5 and the anchor nut 7 are both sleeved on the outside of the stainless steel grouting pipe 1. The anchor nut 7 is threadedly connected to the connecting pipe section 12. The inner end face of the anchor nut 7 faces the inner end of the stainless steel grouting pipe 1. The inner end face of the anchor nut 7 matches and abuts (fully fits) the outer end face of the pad 5.
[0030] The outer diameter of the stainless steel grouting pipe 1 is 100mm to 300mm, the wall thickness of the stainless steel grouting pipe 1 is 8mm to 10mm, the inner end of the stainless steel grouting pipe 1 is either closed or open, and the outer end of the stainless steel grouting pipe 1 is open.
[0031] like Figure 3 As shown, the length of the grouting pipe section 11 is 70% to 90% of the length of the stainless steel grouting perforated pipe 1. The inner end of the grouting pipe section 11 coincides with the inner end of the stainless steel grouting perforated pipe 1. Multiple grouting through holes 13 are arranged in regular rows and columns on the pipe wall of the grouting pipe section 11, including rows and columns facing each other and rows and columns staggered.
[0032] like Figure 4 As shown, a grouting body 4 is provided inside the stainless steel grouting pipe 1. Along the direction from the inner end of the stainless steel grouting pipe 1 to the outer end of the stainless steel grouting pipe 1, the grouting body 4 contains a first grouting material inner section 41 and a second grouting material inner section 42 arranged sequentially.
[0033] The grouting body 4 can be made of cement mortar and is used to fill the gaps between the stainless steel grouting pipe 1 and the stiffening body 2, as well as between the stainless steel grouting pipe 1 and the surrounding borehole wall. It connects the stainless steel grouting pipe 1 and the stiffening body 2 to the reinforced slope as a whole, which plays a role in connecting and increasing the strength of the pile. It can also penetrate into the surrounding soil through the grouting through hole 13 on the stainless steel grouting pipe 1 through the grouting pressure, thereby improving the strength of the loose soil layer around the pile.
[0034] The inner end of the first grouting material inner section 41 coincides with the inner end of the stainless steel grouting perforated pipe 1, and the outer end of the first grouting material inner section 41 is located in the middle of the stainless steel grouting perforated pipe 1. The inner end of the second grouting material inner section 42 is located in the middle of the stainless steel grouting perforated pipe 1, and the outer end of the second grouting material inner section 42 is located inside the outer end of the stainless steel grouting perforated pipe 1. The specific lengths of the first grouting material inner section 41 and the second grouting material inner section 42 can be obtained as needed or through a limited number of experiments.
[0035] Both the pre-grouting material inner section 41 and the post-grouting material inner section 42 are made of hardened cement mortar, i.e., the product of cement mortar after solidification. A grout-stopping plug 3 is installed between the pre-grouting material inner section 41 and the post-grouting material inner section 42. The grout-stopping plug 3 can be a product of existing technology. The position of the grout-stopping plug 3 can be determined as needed. During grouting construction, the micro-pipe pile is divided into the pre-grouting material inner section 41 and the post-grouting material inner section 42 by the grout-stopping plug 3.
[0036] like Figure 2 As shown, a stiffening body 2 is fitted inside the stainless steel grouting pipe 1. The stiffening body 2 has a columnar structure, and an annular cavity is formed between the stainless steel grouting pipe 1 and the stiffening body 2. The grouting body 4 fills the annular cavity. The length of the stiffening body 2 is slightly less than the length of the stainless steel grouting pipe 1, and the inner end of the stiffening body 2 is located at the inner end of the stainless steel grouting pipe 1.
[0037] The stiffening body 2 contains multiple threaded steel bars 21 arranged side by side, which are welded together and fixed in place. The axis of the threaded steel bars 21 is parallel to the axis of the stainless steel grouting pipe 1. For example, the stiffening body 2 contains three threaded steel bars 21 arranged side by side, which are welded together and fixed in place. The stiffening body 2 serves to increase the shear and tensile strength of the pile body.
[0038] like Figure 1 As shown, the material of the pad 5 can be stainless steel. The inner diameter of the pad 5 is smaller than the outer diameter of the anchor nut 7, and the outer diameter of the pad 5 is larger than the outer diameter of the anchor nut 7. The pad 5 serves as an anchor, converting the prestress applied to the micro steel pipe pile into pressure applied to the reinforced slope surface, thereby increasing slope stability.
[0039] like Figure 1 As shown, the micro steel pipe pile also includes a centering pad 6, which has a wedge-shaped structure and is also fitted over the stainless steel grouting pipe 1. The centering pad 6 can solve the problem of inconsistent angles between the slope surface 81 and the pad plate 5. The centering pad 6 can be made of reinforced concrete and can be precast or cast in place.
[0040] The anchor nut 7 is a nut that matches the outer diameter of the stainless steel grouting pipe 1. By mechanically tightening the anchor nut 7, the micro steel pipe pile will be tensioned, thereby applying a certain prestress. That is, after tightening the anchor nut 7, the stainless steel grouting pipe 1 can be subjected to a preset tensile stress.
[0041] like Figure 1As shown, when the micro steel pipe pile is installed on the slope 8, the stainless steel grouting pipe 1 is in a horizontal state. The inner end of the stainless steel grouting pipe 1 is located inside the slope 8, and the outer end of the stainless steel grouting pipe 1, the pad 5, and the anchor nut 7 are all located outside the slope surface 81 of the slope 8. The outer end face of the centering pad 6 matches and abuts with the inner end face of the pad 5 (completely fits), and the inner end face of the centering pad 6 matches and abuts with the slope surface 81 of the slope 8 (completely fits). After tightening the anchor nut 7, the stainless steel grouting pipe 1 can be subjected to tension.
[0042] The construction method of micro steel pipe piles is introduced below.
[0043] 1. Use a drilling rig to drill holes on the slope surface 81 of the slope 8 that needs to be reinforced, with a hole diameter Φ of not less than 130mm.
[0044] 2. Install a grout stopper 3 inside the stainless steel grouting pipe 1. The grout stopper 3 is located approximately in the middle of the length of the stainless steel grouting pipe 1. Grouting is performed inside the stainless steel grouting pipe 1 using grouting machinery, i.e., grouting body (cement mortar) is injected. The grouting range is between the grout stopper 3 and the inner end of the stainless steel grouting pipe 1.
[0045] 3. Before the initial setting of the grout 4, a reinforcing body 2 is inserted into the stainless steel grouting pipe 1, and the grout 4 is allowed to solidify to form a hardened cement mortar. Part of the first injected grout 4 is located inside the stainless steel grouting pipe 1, forming the inner section 41 of the first injected grout material, and the other part of the first injected grout 4 is located outside the stainless steel grouting pipe 1, forming the outer section of the first injected grout material.
[0046] 4. Install the pad 5, the centering pad 6, and the anchor nut 7, and tighten the anchor nut 7 so that the pad 5 just reaches the position of the reinforced slope 81. At the same time, start recording the length of the stainless steel grouting pipe 1 protruding from the pad 5 as L1.
[0047] 5. Continue to tighten the anchor nut 7, and use an anchor rod force gauge to measure the prestress on the stainless steel grouting pipe 1. When the designed prestress value is reached, record the length of the stainless steel grouting pipe 1 protruding from the pad 5 as L2, and ΔL=L2-L1. Use ΔL as the calibration value for the subsequent construction of micro steel pipe piles for large-area facilities, so as to achieve the purpose of rapid construction.
[0048] 6. Continue grouting inside the stainless steel grouting pipe 1, extending the grouting range between the grout plug 3 and the outer end of the stainless steel grouting pipe 1, and seal the exposed portion of the low-prestressed micro steel pipe pile on the slope with cement mortar. A portion of the second-injected grout body 4 is located inside the stainless steel grouting pipe 1, forming the inner section 42 of the post-grouting material, while the other portion of the second-injected grout body 4 is located outside the stainless steel grouting pipe 1, forming the outer section of the post-grouting material.
[0049] The above description is merely a specific embodiment of this utility model and should not be construed as limiting the scope of its implementation. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this utility model should still fall within the scope of this utility model. Furthermore, the technical features, technical solutions, and embodiments of this utility model can be freely combined and used.
Claims
1. A micro steel pipe pile characterized by, The micro steel pipe pile includes a stainless steel grouting pipe (1), a pad (5), and an anchor nut (7). Along the direction from the inner end of the stainless steel grouting pipe (1) to the outer end of the stainless steel grouting pipe (1), the pipe wall of the stainless steel grouting pipe (1) contains a grouting pipe section (11) and a connecting pipe section (12) arranged in sequence. The pipe wall of the grouting pipe section (11) is provided with multiple grouting through holes (13). The outer circumferential surface of the connecting pipe section (12) is provided with external threads (14). The pad (5) and the anchor nut (7) are both sleeved on the outside of the stainless steel grouting pipe (1). The anchor nut (7) is threadedly connected to the connecting pipe section (12). The inner end face of the anchor nut (7) faces the inner end of the stainless steel grouting pipe (1). The inner end face of the anchor nut (7) matches and abuts against the outer end face of the pad (5).
2. The micro steel pipe pile according to claim 1, characterized by, The outer diameter of the stainless steel grouting pipe (1) is 100mm to 300mm, the wall thickness of the stainless steel grouting pipe (1) is 8mm to 10mm, the inner end of the stainless steel grouting pipe (1) is either closed or open, and the outer end of the stainless steel grouting pipe (1) is open.
3. The micro steel pipe pile according to claim 1, characterized in that, The length of the grouting pipe section (11) is 70% to 90% of the length of the stainless steel grouting pipe (1), and multiple grouting through holes (13) are arranged in regular rows on the pipe wall of the grouting pipe section (11).
4. The micro steel pipe pile according to claim 1, characterized in that, A grouting body (4) is provided inside the stainless steel grouting pipe (1). Along the direction from the inner end of the stainless steel grouting pipe (1) to the outer end of the stainless steel grouting pipe (1), the grouting body (4) contains a first grouting material inner section (41) and a second grouting material inner section (42) arranged in sequence.
5. The micro steel pipe pile according to claim 4, characterized in that, The materials of the first grouting material inner section (41) and the second grouting material inner section (42) are both hardened cement mortar, and a grout stopper (3) is provided between the first grouting material inner section (41) and the second grouting material inner section (42).
6. The micro steel pipe pile according to claim 1, characterized by The stainless steel grouting pipe (1) is fitted with a stiffening body (2), which has a columnar structure, and an annular cavity is formed between the stainless steel grouting pipe (1) and the stiffening body (2).
7. The micro steel pipe pile according to claim 6, characterized by The stiffening body (2) contains multiple threaded steel bars (21) arranged side by side, which are welded and fixed together. The axis of the threaded steel bars (21) is parallel to the axis of the stainless steel grouting pipe (1).
8. The micro steel pipe pile according to claim 1, characterized by The pad (5) is made of stainless steel. The inner diameter of the pad (5) is smaller than the outer diameter of the anchor nut (7), and the outer diameter of the pad (5) is larger than the outer diameter of the anchor nut (7).
9. The micro steel pipe pile according to claim 1, characterized by, The micro steel pipe pile also includes a centering pad (6), which has a wedge-shaped structure and is also fitted over the stainless steel grouting pipe (1). When the micro steel pipe pile is installed on the slope (8), the stainless steel grouting pipe (1) is in a horizontal state. The inner end of the stainless steel grouting pipe (1) is located inside the slope (8), and the outer end of the stainless steel grouting pipe (1), the pad (5), and the anchor nut (7) are all located outside the slope surface (81) of the slope (8). The outer end face of the centering pad (6) matches and abuts with the inner end face of the pad (5), and the inner end face of the centering pad (6) matches and abuts with the slope surface (81) of the slope (8). After tightening the anchor nut (7), the stainless steel grouting pipe (1) can be subjected to tension.
10. The micro steel pipe pile according to claim 9, characterized by The material of the centering pad (6) is reinforced concrete.