A new type of pull-out pile structure

Abstract

The invention discloses a novel pull-out pile structure, which belongs to the technical field of building pile foundation. The pull-out pile body is a variable diameter pile body, and the pull-out reinforcement body is located at the center of the concrete pile body and runs through the entire concrete pile body. The lower part of the pull-out reinforcement body is inserted into the circular slot of the steel bar slot disk, and is anchored in the pile head with a nut, and the upper part is fixed with two nuts on the support plate, and cast in the foundation cap. A sleeve is arranged outside the pull-out reinforcement body to prevent the corrosion and cracking of the pull-out reinforcement body, and there is no adhesion between the pull-out reinforcement body and the concrete, and relative slip can occur between the two. One end of the steel bar in the expanded pile body is fixed in the steel bar slot disk, and the other end is spread out at equal angles under the constraint of the braided rope, and is filled in the entire expanded pile body in an umbrella shape. The invention is cleverly designed, and the pull-out pile body with a variable diameter is used, and the expanded pile body is used as the pile bottom, and umbrella-shaped steel bars are placed therein to achieve the purpose of improving the pull-out resistance, and the sleeve is arranged outside the pull-out reinforcement body, which can further enhance its durability.

Description

Technical Field

[0001] The invention relates to the technical field of building pile foundations, and in particular to a novel pull-out resistant pile structure. Background Art

[0002] With the continuous improvement of the level of construction technology, people's demand for buildings is increasing, and the requirements for the pile foundation of buildings are also increasing. In many cases, the pile foundation not only requires a certain pressure resistance, but also a certain pull-out resistance. At the same time, urban space is becoming increasingly scarce, which has caused a boom in underground space development. The development and use of underground projects are affected by the buoyancy of groundwater. Therefore, pull-out piles play an increasingly important role in engineering. Pull-out piles are located underground, surrounded by water and soil. In order to prevent the corrosion of steel bars by groundwater and other chemical substances, there are strict regulatory requirements for cracks in pull-out piles. A fiber reinforced concrete pull-out pile is disclosed in Chinese patent document publication number CN101761089A. The pull-out pile prevents rust by arranging a casing on the outside of the fiber reinforcement, but its pull-out resistance needs to be further improved. The present invention further improves the pull-out resistance on this basis. At the same time, it also takes into account economy and reduces costs. Summary of the invention

[0003] In order to solve the above-mentioned technical problems such as insufficient pull-out resistance, the present invention provides a new type of pull-out pile structure with strong pull-out resistance and high economic efficiency, which can not only greatly reduce the possibility of steel bar corrosion, but also improve the pull-out resistance and anti-floating performance of the pull-out pile and enhance its durability. The present invention achieves the purpose of improving the pull-out resistance by placing an umbrella-shaped steel bar bundle in the expanded pile body of the pull-out pile body with a variable diameter.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: a new type of pull-out pile structure, the pile body is different from the ordinary pull-out pile body, the pull-out pile body is composed of an ordinary pile body A and an enlarged pile body B, forming an enlarged head pull-out pile, which is a variable diameter pile body, and the formation of the pile body can be made by using the contents disclosed in patents such as publication number CN109736709A. The pull-out reinforcement body is located in the center of the concrete pile body, the diameter of the sleeve sleeved outside the pull-out reinforcement body is larger than the diameter of the pull-out reinforcement body, and a space is left between the two to generate relative slip, and the umbrella-shaped steel bar bundle is located in the concrete pile body B, filling it in an umbrella shape.

[0005] The anti-pullout reinforcement body is a steel bar or a steel pipe, with twisted wires at the upper and lower parts for fixing with nuts. The lower part is inserted into the circular slot of the steel bar slot plate and anchored in the pile head with nuts to keep it perpendicular to the center of the concrete pile body. The upper part uses two nuts to fix the support plate on it and cast it in the foundation pedestal.

[0006] The sleeve is a steel round tube, the length of which is slightly greater than the length of the pull-out pile body, and is sleeved outside the pull-out reinforcement body. A space is left between the sleeve and the pull-out reinforcement body so that the two can produce relative slippage. The sleeve diameter is slightly smaller than the diameter of the circular groove in the middle of the steel bar groove disk, and the sleeve is inserted into the circular groove of the steel bar groove disk together with the pull-out reinforcement body, and is fixed with a nut after insertion.

[0007] The steel bar slot plate is a steel circular flat plate with a hollow circular slot in the middle. The diameter of the circular slot is slightly larger than the diameter of the anti-pullout reinforcement body. Several symmetrical rectangular slots are arranged around it. The number of steel bars placed in each slot is equal, so that the steel bars can be opened at equal angles after the steel wire is pulled out. Several annular holes are arranged on both sides of the rectangular slot, and the number of annular holes corresponds to the number of steel bars placed in each slot. Taking 6 rectangular slots as an example, 3 steel bars are placed in each slot, and there are three corresponding pairs of annular holes on both sides of each rectangular slot so that the elastic pins at the bottom of the steel bars can be inserted accordingly.

[0008] Each steel bar of the umbrella-shaped steel bar bundle has a hole at the bottom, and the hole diameter is adapted to the pin shaft so that the pin shaft can be smoothly inserted. The pin shaft is used to fix it in the annular hole in the steel bar slot plate to form a rotatable hinge. The upper part is connected to the sleeve by a braided rope. After the binding steel wire is pulled out, the bottom of the steel bar starts to rotate under the action of the pin shaft, and the steel bar rotates around the pin shaft and spreads out. It stops rotating when it reaches the maximum spreading angle under the constraint of the braided rope, forming an umbrella shape with equal angles.

[0009] The braided rope is used to connect the sleeve and each steel bar of the umbrella-shaped steel bar bundle. One end is tied to the sleeve and the other end is tied to the upper part of the steel bar. The rope should be strong enough to ensure that it is not broken when it is spread out. The length of the braided rope connecting each circle of steel bars of the umbrella-shaped steel bar bundle in the rectangular slot of the steel bar slot plate is equal. After spreading, each circle of steel bars of the umbrella-shaped steel bar bundle are distributed at equal angles in the pile body B.

[0010] The steel wire is annular, and the umbrella-shaped steel bar bundle is tied and gathered so that it can pass through the ordinary pile body A to the bottom of the expanded pile body B. A long rope handle is left on it. After the anti-pullout reinforcement body and the umbrella-shaped steel bar bundle are in place, the steel wire is pulled off through the long rope handle, and the umbrella-shaped steel bar bundle opens in an umbrella shape and fills the entire pile body B.

[0011] Compared with the prior art, the invention has the following beneficial effects: ingenious structure, convenient construction, and the combination of the enlarged head pile body and the ordinary diameter pile body can not only increase the pull-out effect, but also reduce the steel bar material. One end of the pull-out reinforcement body is fixed in the cap, subjected to the upward pulling force, and one end is anchored at the bottom of the pile to prevent it from moving upward. The pull-out reinforcement body, the sleeve, the umbrella-shaped steel bar bundle, the steel bar clamping plate and the braided rope form an integral body. The pull-out reinforcement body is located at the center of the whole body, the sleeve is sleeved outside the pull-out reinforcement body, each steel bar of the umbrella-shaped steel bar bundle is evenly arranged around the pull-out reinforcement body, the braided rope connects the sleeve with each steel bar, and the whole is placed in the pile body. When it reaches the bottom of the pile, the steel wire is pulled off to make the steel bars spread out at equal angles. When the pull-out reinforcement body is subjected to the upward pulling force, the steel bars in the enlarged head pile body will also play a role in preventing it from moving upward, further increasing the pull-out capacity. At the same time, the sleeve is arranged outside the pull-out reinforcement body, which can not only improve its performance, but also prevent it from being eroded by groundwater or chemical substances. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for the technical description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0013] Figure 1 This is a schematic diagram of the structure of the novel pull-out pile of the present invention;

[0014] Figure 2 This is a schematic diagram of the structure of the novel pull-out pile before the steel wire is pulled out of the present invention;

[0015] Figure 3 This is a schematic diagram of a steel bar slot plate of the present invention;

[0016] Figure 4 It is a cross-sectional view of II of the present invention;

[0017] Figure 5 It is a top view of the II-II section after the umbrella-shaped steel bars in the novel pull-out pile of the present invention are spread out and before concrete is poured.

[0018] In the attached Figure 1 ~Attached Figure 5 In the figure, 1 is a steel bar slot plate; 2 is a pile head; 3 is an umbrella-shaped steel bar bundle; 4 is a casing; 5 is an anti-pullout reinforcement body; 6 is a pile body B; 7 is a pile body A; 8 is a cap; 9 is a supporting plate; 10 is a steel wire; 11 is a braided rope; 12 is a circular slot; 13 is a rectangular slot; and 14 is a ring hole. Specific implementation methods

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0020] Figure 1 It is a schematic diagram of the overall structure of the new type of pull-out pile of the present invention, which consists of a pull-out reinforcement body 5 with an external casing 4, a pile body A7, a pile body B6, a steel bar slot plate 1, a pile head 2, an umbrella-shaped steel bar bundle 3, a cap 8, a support plate 9 and a braided rope 11. Figure 2 The state of the umbrella-shaped reinforcement bundle 3 being tied before the steel wire 10 is pulled off is Figure 1 In the early stage, the umbrella-shaped steel bar tendon 3 is bound so that it can pass through the ordinary pile body A7 and reach the pile body B6. Figure 3 The schematic diagram of the steel bar slot plate 1 includes a circular slot 12, a rectangular slot 13 and an annular hole 14. In this example, six rectangular slots 13 are provided. Three pairs of annular holes 14 are provided on both sides of each rectangular slot 13 for inserting the pin shaft. The holes can be adjusted according to the actual situation and prefabricated and installed in the factory. The present invention provides a novel pull-out pile structure, which is characterized in that the construction steps are as follows:

[0021] (1) Use a professional hole-enlarging drill, such as an inverted umbrella-shaped enlargement head drill disclosed in publication number CN109736709A, to operate the drill, and control the enlargement scale of the drill according to the required size to form a hole such as Figure 1 The variable diameter pile shaft shown;

[0022] (2) Figure 2 As shown, the prefabricated steel bar slot plate 1, sleeve 4, anti-pulling reinforcement body 5, umbrella-shaped steel bar bundle 3 and braided rope 11 are assembled to form a whole. First, the anti-pulling reinforcement body 5 is vertically inserted into the steel bar slot plate 1, and the bottom is tightened with a nut to fix it in the steel bar slot plate 1. The sleeve 4 is arranged outside the anti-pulling reinforcement body 5, and the bottom of the sleeve 4 is inserted into the steel bar slot plate 1. Next, each steel bar in the umbrella-shaped steel bar bundle 3 is sequentially inserted from the inner circle to the outer circle into the rectangular slot 13 of the steel bar slot plate 1. After all the insertions are completed, each steel bar in the umbrella-shaped steel bar bundle 3 is connected to the sleeve 4 with a braided rope 11. Finally, the umbrella-shaped steel bar bundle 3 and the anti-pulling reinforcement body 5 are tied together with a steel wire 10 to form a whole, and this whole is vertically placed at the bottom of the anti-pulling pile.

[0023] (3) Figure 1 As shown, when the anti-pullout reinforcement body 5 and the umbrella-shaped reinforcement bundle 3 are in place, the steel wire 10 is pulled out, and it is checked whether each circle of the umbrella-shaped reinforcement bundle 3 is spread out at an equal angle. After the reinforcement is completely spread out, concrete is poured into piles. After the piles are completed, the upper part of the anti-pullout reinforcement body 5 is fixed with two nuts to the support plate 9, and poured into the foundation cap 8;

[0024] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A novel pull-out pile structure, wherein the pull-out pile body is composed of a common pile body A (7) and an enlarged pile body B (6), and is a variable diameter pile body, characterized in that: The anti-pullout reinforcement body (5) is located at the center of the concrete pile body. The diameter of the sleeve (4) sleeved outside the anti-pullout reinforcement body (5) is larger than the diameter of the anti-pullout reinforcement body (5), and a space is left between the two. The umbrella-shaped steel bar bundle (3) is located in the concrete pile body B (6). The anti-pullout reinforcement body (5) is a steel bar or a steel pipe, and its upper and lower parts are twisted wires. The lower part is inserted into the circular groove (12) of the steel bar groove plate (1) and anchored in the pile head (2) with nuts. The upper part is fixed with a support plate (9) with two nuts, and cast in the foundation pedestal (8). The steel bar groove plate (1) is a steel circular flat plate, and a hollow circular groove (12) is provided in the middle, and a plurality of symmetrical rectangular grooves are provided around it. A rectangular slot (13) is provided, and a plurality of annular holes (14) are provided on both sides of the rectangular slot (13). The bottom of the umbrella-shaped steel bar bundle (3) is opened, and is fixed in the annular hole (14) in the steel bar slot plate (1) by a pin shaft to form a rotatable hinge. The upper part is connected to the sleeve (4) through a braided rope (11), and the braided rope (11) is used to connect the sleeve (4) and each steel bar of the umbrella-shaped steel bar bundle (3), wherein the braided rope (11) connecting each circle of steel bars of the umbrella-shaped steel bar bundle (3) in the rectangular slot (13) of the steel bar slot plate (1) is equal in length, and after being spread out, each circle of steel bars of the umbrella-shaped steel bar bundle (3) is distributed in the pile body B (6) at equal angles.

2. A novel pull-out pile structure according to claim 1, characterized in that: The sleeve (4) is a steel round tube, which is sleeved outside the anti-pullout reinforcement body (5). The space between the sleeve (4) and the anti-pullout reinforcement body (5) is empty. Its diameter is slightly smaller than the diameter of the circular groove in the middle of the steel bar groove plate (1). The sleeve (4) and the anti-pullout reinforcement body (5) are inserted into the circular groove of the steel bar groove plate (1) together with the anti-pullout reinforcement body (5).

3. A novel pull-out pile structure according to claim 1, characterized in that: The steel wire (10) is annular and is used to bind and gather the umbrella-shaped reinforcement bundle (3). A long rope handle is left on the steel wire. After the anti-pullout reinforcement body (5) and the umbrella-shaped reinforcement bundle (3) are in place, the steel wire (10) is pulled off through the long rope handle, and the umbrella-shaped reinforcement bundle (3) opens in an umbrella shape.

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