Forward spiral steel core cement-soil mixing pile

Abstract

The utility model discloses a positive spiral steel core cement soil mixing pile which comprises a positive spiral steel core, a cement soil mixing pile body and a guide sleeve arranged at the top of the cement soil mixing pile body, the positive spiral steel core comprises a positive spiral steel plate and a flange plate fixed to the top of the positive spiral steel plate, and the positive spiral steel plate is arranged in the cement soil mixing pile body; the guide sleeve comprises a guide pipe and an insertion hole plate fixed to the top of the guide pipe, the guide pipe is vertically arranged in the cement soil mixing pile, the inner diameter of the guide pipe is matched with the width of the positive spiral steel plate, and a steel plate passing hole is formed in the insertion hole plate; the shape of the steel plate passing hole is matched with that of the cross section of the positive spiral steel plate; the flange plate is used for being connected with a pile pressing machine, and the positive spiral steel plate can be inserted into the guide pipe from the hole inserting plate under the static pressure effect of the pile pressing machine and rotationally penetrates into the cement-soil mixing pile. The defects of an existing concrete core cement soil mixing pile are overcome.

Description

Technical Field

[0001] The utility model relates to the technical field of soft soil foundation treatment, in particular to a positive spiral steel core cement-soil mixing pile. Background Technique

[0002] Soft soil is widely distributed in coastal areas, both sides of inland rivers, and around lakes. Such soil is characterized by high natural water content, large natural void ratio, low shear strength, high compression coefficient, and small permeability coefficient. When carrying out civil engineering construction on soft soil foundation, it is usually necessary to improve the natural foundation to form an artificial foundation that meets the requirements of buildings.

[0003] When carrying out deep foundation treatment, the commonly used method is to use cement-soil mixing piles for reinforcement. Cement-soil mixing piles are widely used because of their advantages such as no vibration, no noise, and no pollution. However, due to the limited strength of the pile body, the bearing capacity of a single pile is limited. Therefore, in the prior art, precast concrete piles (concrete cores) are usually inserted into cement-soil mixing piles to form concrete core cement-soil mixing piles, so as to maximize the strength of each material of the pile body and thus improve the bearing capacity.

[0004] However, there are still some problems with concrete core cement-soil mixing piles in engineering practice. For example, when the concrete core is inserted into the cement-soil mixing pile in sections, the verticality may deviate, resulting in the ineffective use of the pile and causing material waste; the bonding firmness between the concrete core and the cement-soil mixing pile is not high, and they cannot be tightly combined into one body, causing the separation of the two and unable to play a good reinforcement role. Summary of the Invention

[0005] The utility model provides a positive spiral steel core cement-soil mixing pile to overcome the deficiencies of existing concrete core cement-soil mixing piles.

[0006] In order to achieve the above purpose, the technical solution of the utility model is:

[0007] A positive spiral steel core cement-soil mixing pile includes a positive spiral steel core, a cement-soil mixing pile, and a guiding sleeve arranged at the top of the cement-soil mixing pile. The positive spiral steel core includes a positive spiral steel plate and a flange plate fixed at the top of the positive spiral steel plate. The positive spiral steel plate is arranged inside the cement-soil mixing pile;

[0008] The guiding sleeve includes a guiding pipe and a socket plate fixed at the top of the guiding pipe. The guiding pipe is vertically arranged inside the cement-soil mixing pile. The inner diameter of the guiding pipe matches the width of the positive spiral steel plate. The socket plate is provided with a steel plate through hole, and the shape of the steel plate through hole matches the cross-sectional shape of the positive spiral steel plate;

[0009] The flange is used to connect the pile press. Under the static pressure of the pile press, the positive spiral steel plate can be inserted into the guide pipe from the socket plate and rotate into the soil-cement mixing pile.

[0010] Further, it also includes a connecting rod and a soil nail. The connecting rod is arranged at the top of the soil-cement mixing pile. One end of the connecting rod is fixed on the socket plate, and the other end of the connecting rod is provided with a nail inserting pipe. The soil nail is inserted into the soft soil foundation along the nail inserting pipe.

[0011] Further, the number of the connecting rods and the soil nails is three. The three connecting rods are evenly distributed on the socket plate, and the three soil nails are arranged in a triangular array.

[0012] Further, the positive spiral steel core further includes an extension rod with both ends fixedly connected to the positive spiral steel plate and the flange respectively. The length of the extension rod is not less than the length of the guide pipe.

[0013] Further, the torsion angle of the positive spiral steel plate is not greater than 45 degrees and greater than 0 degree.

[0014] Further, the torsion angle of the positive spiral steel plate is 45 degrees.

[0015] Beneficial effects:

[0016] Compared with the prior art of inserting precast concrete piles into soil-cement mixing piles, a positive spiral steel core soil-cement mixing pile provided by the present utility model inserts a guide casing into the soil-cement mixing pile, so that the positive spiral steel core rotates into the soil-cement mixing pile through the guide casing, ensuring the verticality of the positive spiral steel core through the guide casing. At the same time, by using the differential geometric characteristics of the positive spiral steel plate, the contact area between the positive spiral steel plate and the soil-cement mixing pile is increased. The positive spiral steel core and the soil-cement mixing pile are mutually embedded and engaged, enhancing the bonding firmness between the positive spiral steel core and the soil-cement mixing pile, ensuring that the positive spiral steel core and the soil-cement mixing pile can work together, ensuring that the upper load of the soil-cement mixing pile can be transmitted deeper into the foundation, giving full play to the bearing characteristics of the positive spiral steel core and the soil-cement mixing pile. Therefore, it has extremely high vertical bearing capacity and has a good reinforcement effect on soft soil foundation, meeting the requirements of buildings (structures) for foundation treatment. Description of the drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1Schematic diagram of a positive spiral steel core cement-soil mixing pile for soft soil foundation disclosed by the present utility model;

[0019] Figure 2 Cross-sectional view of a positive spiral steel core cement-soil mixing pile for soft soil foundation disclosed by the present utility model;

[0020] Figure 3 is Figure 2 enlarged view of part B of;

[0021] Figure 4 Schematic diagram of the structure of the positive spiral steel core of a positive spiral steel core cement-soil mixing pile disclosed by the present utility model;

[0022] Figure 5 Schematic diagram of the structure of the guide casing of a positive spiral steel core cement-soil mixing pile disclosed by the present utility model Figure 1 ;

[0023] Figure 6 Schematic diagram of the structure of the guide casing of a positive spiral steel core cement-soil mixing pile disclosed by the present utility model Figure 2 ;

[0024] Figure 7 Schematic diagram of the torsion angle of the positive spiral steel plate of a positive spiral steel core cement-soil mixing pile disclosed by the present utility model.

[0025] In the figure:

[0026] 1. Positive spiral steel plate; 2. Flange; 3. Cement-soil mixing pile; 4. Guide pipe; 5. Jacking plate; 501. Steel plate through-hole; 6. Connecting rod; 7. Soil nail; 8. Plugging pipe; 9. Extension rod; A. Soft soil foundation. Specific embodiments

[0027] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some but not all of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0028] This embodiment provides a positive spiral steel core cement-soil mixing pile, as Figures 1 to 3 shown, including a positive spiral steel core, a cement-soil mixing pile 3 and a guide casing provided at the top of the cement-soil mixing pile 3, as Figure 4 shown, the positive spiral steel core includes a positive spiral steel plate 1 and a flange 2 welded and fixed to the top of the positive spiral steel plate 1, and the positive spiral steel plate 1 is arranged inside the cement-soil mixing pile 3;

[0029] As shown Figure 5 in the figure, the guiding casing includes a guiding pipe 4 and a socket plate 5 welded and fixed to the top of the guiding pipe 4. The guiding pipe 4 is vertically arranged in the soil-cement mixing pile 3. The inner diameter of the guiding pipe 4 matches the width of the positive spiral steel plate 1. The socket plate 5 is provided with a steel plate passing hole 501, and the shape of the steel plate passing hole 501 matches the shape of the cross-section of the positive spiral steel plate 1. The steel plate passing hole 501 enables each cross-section of the positive spiral steel plate 1 to be inserted into the soil-cement mixing pile 3 at exactly the same position;

[0030] The flange plate 2 is used to connect the pile press. Under the static pressure of the pile press, the positive spiral steel plate 1 can be inserted into the guiding pipe 4 from the socket plate 5 and rotate and penetrate into the soil-cement mixing pile 3;

[0031] Compared with the prior art of inserting precast concrete piles into soil-cement mixing piles, a positive spiral steel core soil-cement mixing pile provided in this embodiment inserts a guiding casing into the soil-cement mixing pile 3, so that the positive spiral steel core rotates and penetrates into the soil-cement mixing pile 3 through the guiding casing, ensuring the verticality of the positive spiral steel core through the guiding casing. At the same time, by utilizing the differential geometric characteristics of the positive spiral steel plate 1, the positive spiral steel core and the soil-cement mixing pile 3 are mutually embedded and engaged, increasing the contact area between the positive spiral steel plate 1 and the soil-cement mixing pile 3, enhancing the bonding firmness between the positive spiral steel core and the soil-cement mixing pile 3, ensuring that the upper load of the soil-cement mixing pile 3 can be transmitted deeper into the soft soil foundation. Under the action of vertical compressive load, the positive spiral steel plate 1 in the shape of a positive spiral surface extrudes the soil-cement mixing pile 3 in contact with it, giving full play to the compressive strength of the soil-cement material itself, and transferring a large amount of the upper load borne by the positive spiral steel core to the soil-cement mixing pile 3 in the form of compressive stress, ensuring that the positive spiral steel core and the soil-cement mixing pile 3 can work together and giving full play to the bearing characteristics of the positive spiral steel core and the soil-cement mixing pile 3. Therefore, it has extremely high vertical bearing capacity and has a good reinforcement effect on the soft soil foundation A;

[0032] In this embodiment, it is connected to a trolley-type pile press through the flange plate 2. The positive spiral steel plate 1 rotates and penetrates into the soil-cement mixing pile 3 under the action of static pressure. The rotation and penetration of the positive spiral steel plate 1 enable the positive spiral steel core to be inserted into the soil-cement mixing pile 3 without a large construction load, with less disturbance to the soil-cement mixing pile 3, and will not cause a large amount of mortar in the soil-cement mixing pile 3 to overflow and cause environmental pollution, realizing vibration-free construction, being able to reduce construction noise, having less impact on the surrounding environment, and making the construction process more environmentally friendly.

[0033] A positive spiral steel core soil-cement mixing pile provided in this embodiment combines the load-bearing characteristics of the positive spiral steel core and the soil-cement mixing pile 3. The pile side friction resistance is provided through the large contact area between the soil-cement mixing pile 3 and the soft soil foundation A, and the high-strength positive spiral steel core is used to bear the vertical load, so that the advantages of the two pile types are fully exerted at the same time, and it has extremely high vertical bearing capacity. Under the action of vertical compression load, most of the load at the pile top is borne by the positive spiral steel core and is mainly transmitted to the soil-cement mixing pile 3 in the form of compressive stress, and then transmitted to the soft soil foundation A around the pile by the soil-cement mixing pile 3; the load is transferred from the positive spiral steel core through the soil-cement mixing pile 3 to the soft soil foundation A around the pile, and the compressive strength shows a gradual change from strong to medium to weak, and the upper load is effectively transferred and diffused to the wider and deeper soft soil foundation A. In this way, the bearing capacity of the pile-soil system is improved, the stability performance of the pile-soil system is strengthened, and the deformation settlement of the pile-soil system is reduced. It can be widely used in the treatment of soft clay foundations. Compared with the current technology of inserting precast concrete piles into soil-cement mixing piles, it has lower construction difficulty, shorter construction period and lower construction cost.

[0034] In practical applications, it should be ensured that the surface of the guide pipe 4 of the guide casing is smooth to reduce the friction between the guide pipe 4 and the soil-cement mixing pile 3, so as to ensure that the upper load can be transmitted downward along the positive spiral steel core as much as possible.

[0035] In a specific embodiment, as Figure 3 and Figure 5 shown, it further includes a connecting rod 6 and a soil nail 7. The connecting rod 6 is arranged at the top of the soil-cement mixing pile 3. In this embodiment, the connecting rod 6 is inserted into the not yet fully solidified soil-cement mixing pile 3 together with the guide casing. After the soil-cement mixing pile 3 is completely solidified, it forms an integral body with the soil-cement mixing pile 3. One end of the connecting rod 6 is welded and fixed on the jacking plate 5, and a nail inserting pipe 8 is welded to the other end of the connecting rod 6. The soil nail 7 is inserted into the soft soil foundation A along the nail inserting pipe 8 to play a reinforcement role and prevent the guide casing from loosening;

[0036] In this embodiment, as Figure 6 shown, the end of the connecting rod 6 is welded at the intersection of the guide pipe 4 and the jacking plate 5, and the end of the connecting rod 6 is welded and fixed to both the guide pipe 4 and the jacking plate 5 at the same time to increase the connection strength by increasing the contact area.

[0037] In a specific embodiment, the number of the connecting rods 6 and the soil nails 7 is three each. As Figure 5 shown, the three connecting rods 6 are evenly distributed on the jacking plate 5, and the included angles between the three connecting rods 6 are all 120°. The three soil nails 7 are arranged in a triangular array. The triangular arrangement can improve the stability and save materials at the same time.

[0038] In a specific embodiment, as Figure 4 shown, the positive spiral steel core further includes an extension rod 9 whose two ends are respectively welded and fixed to the positive spiral steel plate 1 and the flange 2. The length of the extension rod 9 is not less than the length of the guide pipe 4. The positive spiral steel plate 1 in the guide pipe 4 cannot be well combined with the cement-soil mixing pile 3, which is likely to cause waste. The setting of the extension rod 9 can reduce the waste of the positive spiral steel plate 1 and lower the production cost;

[0039] In this embodiment, the diameter of the extension rod 9 is greater than the thickness of the positive spiral steel plate 1. To ensure normal use, as shown in the figure, a round hole allowing the extension rod 9 to pass through is opened in the middle of the steel plate through hole 501.

[0040] In a specific embodiment, the torsion angle of the positive spiral steel plate 1 is not greater than 45 degrees and greater than 0 degree. Preferably, as Figure 7 shown, the torsion angle of the positive spiral steel plate 1 is 45 degrees. In actual production, the steel plate meeting the design requirements can be processed by the torsion method. Fix the two ends in the long axis direction of the steel plate on the torsion machine respectively, apply torque in the long axis direction of the steel plate through the torsion machine to twist the steel plate, so that the angle formed by the edge of the steel plate and the long axis direction is 45°, to obtain the positive spiral steel plate 1. The torsion angle of the steel plate generally does not exceed 45° to prevent excessive plastic deformation of the steel.

[0041] In actual application, after the pile positions are arranged on the soft soil foundation A by using a theodolite and a tape measure, a deep mixing pile machine is used to construct the cement-soil mixing pile 3 at the designated pile positions. After the construction of the cement-soil mixing pile 3 is completed, the guide casing is inserted into the cement-soil mixing pile 3, and the soil nail 7 is fixed on the soft soil foundation A. The positive spiral steel core passing through the guide casing is rotationally pressed into the cement-soil mixing pile 3 by a trolley type pile press. To ensure the smooth progress of the construction, the positive spiral steel core must be inserted within 12 hours after the construction of the cement-soil mixing pile 3 is completed to avoid the complete solidification of the cement-soil mixing pile 3.

[0042] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A positive spiral steel core cement soil mixing pile, characterized in that: It comprises a positive spiral steel core, a cement soil mixing pile (3) and a guide sleeve arranged on the top of the cement soil mixing pile (3), the positive spiral steel core comprises a positive spiral steel plate (1) and a flange (2) fixed on the top of the positive spiral steel plate (1), and the positive spiral steel plate (1) is arranged in the cement soil mixing pile (3); The guide sleeve comprises a guide tube (4) and a socket plate (5) fixed on the top of the guide tube (4); the guide tube (4) is vertically arranged in the cement soil mixing pile (3); the inner diameter of the guide tube (4) matches the width of the positive spiral steel plate (1); the socket plate (5) is provided with a steel plate through hole (501); the shape of the steel plate through hole (501) matches the shape of the cross section of the positive spiral steel plate (1); The flange (2) is used to connect a pile driver, and the positive spiral steel plate (1) can be inserted from the socket plate (5) into the guide pipe (4) under the static pressure of the pile driver, and rotated to penetrate into the cement soil mixing pile (3).

2. The positive spiral steel core cement soil mixing pile according to claim 1, characterized in that: It also includes a connecting rod (6) and a soil nail (7), wherein the connecting rod (6) is arranged on the top of the cement soil mixing pile (3), one end of the connecting rod (6) is fixed on the socket plate (5), and the other end of the connecting rod (6) is provided with a nail insertion tube (8), and the soil nail (7) is inserted into the soft soil foundation (A) along the nail insertion tube (8).

3. The positive spiral steel core cement soil mixing pile according to claim 2, characterized in that: The number of the connecting rods (6) and the number of the soil nails (7) are both three, the three connecting rods (6) are evenly distributed on the socket plate (5), and the three soil nails (7) are arranged in a triangular array.

4. The positive spiral steel core cement soil mixing pile according to claim 1, characterized in that: The positive spiral steel core also includes an extension rod (9) whose two ends are respectively fixedly connected to the positive spiral steel plate (1) and the flange (2), and the length of the extension rod (9) is not less than the length of the guide tube (4).

5. The positive spiral steel core cement soil mixing pile according to claim 1, characterized in that: The torsion angle of the positive spiral steel plate (1) is not greater than 45 degrees and greater than 0 degrees.

6. The positive spiral steel core cement soil mixing pile according to claim 5, characterized in that: The torsion angle of the positive spiral steel plate (1) is 45 degrees.

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