A steel pipe composite pile for collapsible loess

Abstract

A steel pipe composite pile for collapsible loess belongs to the technical field of building pipe piles. The steel pipe composite pile for collapsible loess includes a steel pipe sleeve, a steel plug plate, a pile tip and a concrete pile core. The steel plug plate includes a horizontal hollow plug plate and a vertical arc plug plate. The outer wall of the vertical arc plug plate is evenly provided with a plurality of the horizontal hollow plug plates vertically, and a plurality of the steel plug plates are evenly provided inside the steel pipe sleeve. The steel pipe sleeve is evenly provided with a plurality of engaging grooves corresponding to the horizontal hollow plug plates along the circumferential direction for engaging with the horizontal hollow plug plates. The pile tip is arranged at the end of the steel pipe sleeve, and the concrete pile core is arranged inside the steel pipe sleeve. The steel pipe composite pile for collapsible loess can block the soil from collapsing in the horizontal direction and absorb water in the soil to reduce soil settlement, thereby reducing the negative friction on the pile side and improving the bearing capacity of the pile foundation.

Description

Technical Field

[0001] The invention relates to the technical field of building pipe piles, in particular to a steel pipe composite pile used for collapsible loess. Background Art

[0002] In recent years, the use of pile foundations has increased. Pile foundations have good bearing capacity, but because collapsible loess will produce collapsible deformation due to water immersion, the pile foundation will have a large negative friction resistance, which may cause damage to the building in severe cases. Therefore, how to reduce the negative friction resistance of pile foundations in collapsible loess is of great engineering practical significance.

[0003] The existing measures to reduce negative friction are mainly to bury isolation piles or protection piles and pile surface coating. The pile surface coating method is to apply a special asphalt on the pile side surface above the neutral point of the pile. When the soil and the pile are relatively displaced and negative friction occurs, the coating will produce shear strain to reduce the negative friction acting on the pile surface. This is currently considered to be the most effective method to reduce negative friction. However, asphalt will corrode and age when in contact with soil with a high water content for a long time, and eventually fail, making the bearing capacity of the pile foundation insufficient. Summary of the invention

[0004] In order to solve the technical problems existing in the prior art, the present invention provides a steel pipe composite pile for collapsible loess, which can prevent the soil from collapsing in the horizontal direction and absorb water in the soil to reduce soil settlement, thereby reducing the negative friction on the pile side and improving the bearing capacity of the pile foundation.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A steel pipe composite pile for collapsible loess, comprising a steel pipe sleeve, a steel insert plate, a pile tip and a concrete pile core;

[0007] The steel plug plate includes a horizontal hollow plug plate and a vertical arc plug plate, and a plurality of the horizontal hollow plug plates are evenly arranged vertically on the outer wall of the vertical arc plug plate;

[0008] A plurality of the steel inserts are evenly arranged inside the steel pipe sleeve, and a plurality of engaging grooves corresponding to the horizontal hollow inserts are evenly arranged along the circumferential direction of the steel pipe sleeve for engaging with the horizontal hollow inserts;

[0009] The pile tip is arranged at the end of the steel pipe sleeve;

[0010] The concrete pile core is arranged inside the steel pipe sleeve.

[0011] Furthermore, the horizontal hollow plug plate is a hollow structure, with Sanqi ash soil arranged inside, and a plurality of through holes are evenly arranged on the upper surface of the horizontal hollow plug plate for absorbing water in the soil; a pointed end is arranged on the side of the horizontal hollow plug plate away from the vertical arc plug plate for penetrating into the soil layer.

[0012] Furthermore, the inner wall of the vertical arc plug plate is provided with a spiral groove, the central angle corresponding to the arc of the vertical arc plug plate is 70°, and the thickness of the vertical arc plug plate is 20 cm.

[0013] Furthermore, the pile tip is a solid structure for being driven into a hard bearing layer.

[0014] Preferably, the steel pipe sleeve has a diameter of 100 cm and a thickness of 20 cm.

[0015] Preferably, four steel insert plates are evenly arranged inside the steel pipe sleeve.

[0016] Preferably, the width of the horizontal hollow plugboard is 50 cm, the length is greater than or equal to 70 cm, the thickness is 20 cm, and the distance between two vertically adjacent horizontal hollow plugboards is 2 to 3 m.

[0017] Preferably, the outer surfaces of the steel pipe sleeve and the horizontal hollow insert plate are coated with a waterproof coating, which has good corrosion resistance and long service life.

[0018] Beneficial effects of the present invention:

[0019] 1) The present invention has a simple and firm structure, good strength, stable pile foundation, can well reduce the negative friction of the pile foundation, improve the bearing capacity of the pile foundation, has a long service life, good corrosion resistance, and good safety performance;

[0020] 2) Sanqi lime soil is set inside the horizontal hollow plugboard, which is equivalent to the foundation cushion. When the loess meets water, the Sanqi lime soil combines with silicon dioxide or aluminum oxide and ferric oxide in the soil to generate colloidal calcium silicate, calcium aluminate and calcium ferrite, which cement the soil and make the lime soil have higher strength and water resistance. The lime soil gradually hardens, increasing the adhesion strength between soil particles. At the same time, due to the density of the evenly arranged horizontal hollow plugboards, the water settlement of the loess around the pile can be effectively reduced;

[0021] 3) The spiral grooves on the inner wall of the vertical arc-shaped insert plate can be well connected with the concrete pile core, increasing the stability of the structure.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1Schematic diagram of the structure of a steel pipe composite pile for collapsible loess provided by an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A top view of

[0025] Figure 3 It is a structural schematic diagram of a steel pipe sleeve provided in an embodiment of the present invention;

[0026] Figure 4 is a schematic diagram of the structure of a steel insert provided by an embodiment of the present invention;

[0027] Figure 5 is a schematic structural diagram of a spiral groove of a vertical arc-shaped plug plate provided by an embodiment of the present invention;

[0028] Figure 6 It is a cross-sectional view of a horizontal hollow plugboard provided in an embodiment of the present invention.

[0029] The reference numerals in the drawings of the specification include:

[0030] 1-steel pipe sleeve, 2-vertical arc plug plate, 3-pile tip, 4-concrete pile core, 5-horizontal hollow plug plate, 6-tip part, 7-clamping groove, 8-37 ash soil. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "vertical", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0034] In order to solve the problems existing in the prior art, such as Figures 1 to 6As shown, an embodiment of the present invention provides a steel pipe composite pile for collapsible loess, comprising a steel pipe sleeve 1, a steel insert plate, a pile tip 3 and a concrete pile core 4, which is used for the construction of pile foundations in collapsible loess areas, can prevent the soil from collapsing in the horizontal direction and can absorb water in the soil to reduce soil settlement, thereby reducing the negative friction on the pile side and improving the bearing capacity of the pile foundation.

[0035] like Figures 1 to 6 As shown, the steel plug plate includes a horizontal hollow plug plate 5 and a vertical arc plug plate 2. A plurality of horizontal hollow plug plates 5 are evenly arranged vertically on the outer wall of the vertical arc plug plate 2. The horizontal hollow plug plate 5 is a hollow structure, and a three-seven ash soil 8 is arranged inside it to absorb water in the soil. A plurality of through holes are evenly arranged on the upper surface of the horizontal hollow plug plate 5, and a tip portion 6 is arranged on the side away from the vertical arc plug plate 2 to penetrate into the soil layer. The inner wall of the vertical arc plug plate 2 is provided with a spiral groove, and the central angle corresponding to the arc of the vertical arc plug plate 2 is 70°. The thickness of the vertical arc plug plate 2 is 20 cm.

[0036] The inner wall of the vertical arc plug plate 2 is provided with a spiral groove, which is similar to a thread structure, and is used to increase the friction between the steel plug plate and the concrete pile core 4. The horizontal hollow plug plate 5 can effectively reduce the negative friction caused by loess collapse, improve the bearing capacity of the pile, and have a long service life and good safety. The Sanqi ash soil 8 absorbs water in the soil to reduce the settlement of the soil, thereby reducing the negative friction on the pile side and improving the bearing capacity of the pile foundation. In actual work, a plurality of steel pipe composite piles constitute a pile group, and the horizontal hollow plug plates 5 of two adjacent steel pipe composite piles are close or contacted to form a plane, which improves the bearing capacity. In this embodiment, the width of the horizontal hollow plug plate 5 is 50cm, the length is greater than or equal to 70cm, the thickness is 20cm, and the distance between two vertically adjacent horizontal hollow plug plates 5 is 2 to 3m. The distance between two vertically adjacent horizontal hollow plug plates 5 on the vertical arc plug plate 2 is determined according to actual conditions.

[0037] like Figures 1 to 3As shown, several steel plug plates are evenly arranged inside the steel pipe sleeve 1, and several snap-in grooves 7 corresponding to the horizontal hollow plug plates 5 are evenly arranged along the circumference of the steel pipe sleeve 1, which are used to snap-in with the horizontal hollow plug plates 5. The snap-in grooves 7 are arranged around the steel pipe sleeve 1. In the same horizontal direction, one snap-in groove 7 is arranged every 45°; in the vertical direction, one is arranged every 2 to 3m, and the size of the snap-in groove 7 corresponds to the size of the horizontal hollow plug plates 5. The pile tip 3 is arranged at the end of the steel pipe sleeve 1, and the pile tip 3 is a solid structure, which is used to be driven into the hard bearing layer. Specifically, the pile tip 3 is connected to the steel pipe sleeve 1 as a whole. During construction, the pile tip 3 is driven into the hard bearing layer. The concrete pile core 4 is arranged inside the steel pipe sleeve 1. In this embodiment, the diameter of the steel pipe sleeve 1 is 100 cm, and its thickness is 20 cm. The length of the steel pipe sleeve 1 is set according to the thickness of the collapsible loess layer on site, so that the pile tip 3 is driven into the hard bearing layer. Four steel plug plates are evenly arranged inside the steel pipe sleeve 1. After all four steel inserts in the steel pipe sleeve 1 are installed, a concrete pile core 4 is cast on site to form a new type of steel pipe composite pile suitable for collapsible loess. The outer surfaces of the steel pipe sleeve 1 and the horizontal hollow insert 5 are coated with a waterproof coating, which has good corrosion resistance and long service life.

[0038] The construction method of the steel pipe composite pile for collapsible loess is as follows:

[0039] During construction, first drill a hole with a drill rig, drive the steel pipe sleeve 1 with the pile tip 3 into the drill hole, insert the first steel plug plate into the steel pipe sleeve 1, make the horizontal hollow plug plate 5 correspond to the position of the engaging groove 7, drive the horizontal hollow plug plate 5 horizontally into the soil, and engage the horizontal hollow plug plate 5 with the engaging groove 7. Next, insert the second, third, and fourth steel plug plates into the steel pipe sleeve 1 in a clockwise order. When all four steel plug plates are inserted into the soil, pour the concrete pile core 4. Since the inner wall of the vertical arc plug plate 2 is provided with a spiral groove, there is a large friction between the steel pipe composite pile and the concrete, and the structure is stable.

[0040] The present invention forms a pile by compositely connecting a steel pipe sleeve 1, a steel plug plate, a pile tip 3 and a concrete pile core 4, and has a firm structure, which can effectively reduce the negative friction of the pile foundation; after the pile foundation is constructed, due to the proportional relationship between the length of the horizontal hollow plug plate 5 and the pile spacing, the horizontal hollow plug plates 5 of different composite piles in the pile group can be almost connected in the soil, playing the role of a cushion layer, and can well improve the bearing capacity of the pile foundation; a waterproof coating is applied on the outer surface of the steel pipe sleeve 1 and the horizontal hollow plug plate 5, which has good corrosion resistance and a long service life, and the Sanqi lime soil 8 inside the horizontal hollow plug plate 5 can be hydrated to cement the soil and improve the strength.

[0041] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A steel pipe composite pile for collapsible loess, characterized in that: It includes steel pipe sleeve, steel insert plate, pile tip and concrete pile core; The steel plug plate includes a horizontal hollow plug plate and a vertical arc plug plate, and a plurality of the horizontal hollow plug plates are evenly arranged vertically on the outer wall of the vertical arc plug plate; A plurality of the steel inserts are evenly arranged inside the steel pipe sleeve, and a plurality of engaging grooves corresponding to the horizontal hollow inserts are evenly arranged along the circumferential direction of the steel pipe sleeve for engaging with the horizontal hollow inserts; The pile tip is arranged at the end of the steel pipe sleeve; The concrete pile core is arranged inside the steel pipe sleeve; The horizontal hollow plug plate is a hollow structure, with Sanqi ash soil arranged inside, and a plurality of through holes are evenly arranged on the upper surface of the horizontal hollow plug plate for absorbing water in the soil; the inner wall of the vertical arc plug plate is provided with a spiral groove.

2. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: A tip portion is arranged on one side of the horizontal hollow plug plate away from the vertical arc-shaped plug plate for penetrating into the soil layer.

3. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: The central angle of the arc of the vertical arc plug plate is 70°, and the thickness of the vertical arc plug plate is 20 cm.

4. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: The pile tip is a solid structure and is used for being driven into a hard bearing layer.

5. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: The steel pipe sleeve has a diameter of 100 cm and a thickness of 20 cm.

6. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: Four steel insert plates are evenly arranged inside the steel pipe sleeve.

7. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: The width of the horizontal hollow plug board is 50 cm, the length is greater than or equal to 70 cm, the thickness is 20 cm, and the distance between two vertically adjacent horizontal hollow plug boards is 2 to 3 m.

8. The steel pipe composite pile for collapsible loess according to claim 1, characterized in that: The outer surfaces of the steel pipe sleeve and the horizontal hollow insert plate are coated with a waterproof coating.

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