Fabricated short pile-spiral anchor composite foundation

Abstract

The utility model relates to the technical field of power construction, in particular to an assembly type short pile-spiral anchor composite foundation which comprises an anchor rod, a first spiral anchor disc is arranged on the lower section of the anchor rod, a flange plate is arranged at the top end of the anchor rod, and a steel cylinder is arranged on the anchor rod and located between the flange plate and the uppermost first spiral anchor disc. The anchor rod penetrates through the steel cylinder from top to bottom and is coaxial with the central axis of the steel cylinder; the spiral anchor has the advantages that the problem that the horizontal bearing capacity of the spiral anchor is insufficient can be solved under the condition that the advantages that the spiral anchor is convenient and rapid to construct, low in manufacturing cost and capable of rapidly generating the bearing capacity after a pile is formed are kept.

Description

TECHNICAL FIELD

[0001] The utility model relates to power construction technical field especially relates to a fabricated short pile - spiral anchor composite foundation. BACKGROUND

[0002] The power transmission line is the carrier of electric energy transmission in the power system, and in the construction of the power transmission line, the power transmission tower is an important framework structure and is widely used in various voltage grade overhead power transmission lines. Under the action of wind load, conductor load, tower self-weight load and the like, the power transmission tower foundation bears vertical and horizontal composite load. For special corner towers, terminal towers and the like, the horizontal load is larger.

[0003] At present, the power transmission tower foundation types mainly include the expanded foundation, the excavated foundation, the equipped foundation and the spiral anchor foundation, wherein the spiral anchor foundation is widely promoted and applied by the State Grid in recent years because of the advantages of convenient and fast construction, low cost, fast bearing capacity generation after piling and the like. The traditional spiral anchor foundation is composed of an anchor head, a spiral anchor plate and an anchor rod. The anchor rod top is connected with a special torque driving head, and the spiral anchor can be screwed into the soil like a screw. The anchor plate can provide large anchoring force and downward resistance. The horizontal force is mainly borne by the anchor rod. However, limited by the construction equipment, cost, production process and the like, the diameter of the anchor rod is often small (within 630 mm), and the horizontal bearing capacity is limited.

[0004] In order to overcome the problem of insufficient horizontal bearing capacity of the spiral anchor, the current common method is to pour a concrete cap at the top of the spiral anchor, but this will reduce the advantages of convenient and fast construction of the spiral anchor, immediate bearing capacity generation after piling and the like, and the cap excavation will cause adverse effects on the surrounding environment. Another method is to use three or more straight anchors and inclined anchors to form a spiral group anchor, to provide horizontal resistance by using the group anchor foundation, and to connect the steel cap with the spiral anchor, but this method has the disadvantages of reducing the low cost advantage of the spiral anchor, and on the other hand, the construction precision requirement of the steel cap is high, which reduces the advantage of convenient construction of the spiral anchor.

[0005] Based on this, the present case is proposed. CONTENT OF THE UTILITY MODEL

[0006] The utility model aims at providing a fabricated short pile - spiral anchor composite foundation, solving the problem of insufficient horizontal bearing capacity of the spiral anchor, and maintaining the advantages of convenient and fast construction of the spiral anchor, immediate bearing capacity generation after piling and the like.

[0007] In order to achieve the above-mentioned purpose, the technical scheme of the utility model is as follows:

[0008] An assembled short pile-spiral anchor composite foundation, comprising an anchor rod, a plurality of spiral anchor discs one arranged on a lower section of the anchor rod, and a flange plate arranged at a top end of the anchor rod, a steel cylinder arranged on the anchor rod, the steel cylinder being located between the flange plate and the uppermost spiral anchor disc one, and the anchor rod penetrating through the steel cylinder and being coaxial with a central axis of the steel cylinder from top to bottom.

[0009] Further, the first form of the steel cylinder is a hollow and closed structure, and a bottom surface of the steel cylinder is a spiral anchor disc two with a diameter larger than an outer diameter of a cylinder body.

[0010] Further, the second form of the steel cylinder is an open structure at both upper and lower ends and a hollow structure, and a space between an inner wall of the steel cylinder and the anchor rod is filled with concrete.

[0011] The assembled short pile-spiral anchor composite foundation has the advantages that: the upper part of the foundation is provided with an assembled steel cylinder short pile, and the lower part is a steel spiral anchor foundation, the foundation combines the respective advantages of the spiral anchor and the short pile foundation, the upper part of the steel cylinder short pile bears most of the horizontal load, the shortcoming of poor horizontal bearing capacity of the traditional spiral anchor foundation is made up, the lower part of the spiral anchor bears most of the vertical load, and the overall stress of the foundation is greatly strengthened; meanwhile, the construction precision of a single spiral anchor is more easily controlled, and the construction difficulty is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 FIG. 1 is a schematic view of a full assembled short pile-spiral anchor composite foundation in Embodiment 1;

[0013] Figure 2 FIG. 2 is a schematic view of an assembled short pile-spiral anchor composite foundation in Embodiment 2;

[0014] REFERENCE NUMERALS

[0015] 1, anchor rod; 2, flange plate; 3, spiral anchor disc one; 4, spiral anchor disc two; 5, steel cylinder; 6, concrete prefabricated block. DETAILED DESCRIPTION

[0016] The utility model will be described in further detail in combination with embodiments, and it needs to be understood that the directions or position relations of terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer" and the like in the text are based on the directions or position relations shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and cannot be understood as indicating or implying that the devices or elements indicated must have a specific direction, a specific direction structure and operation, and therefore cannot be understood as a limitation on the utility model. Embodiment 1

[0017] As Figure 1As shown, this embodiment proposes a fully prefabricated short pile-spiral anchor composite foundation, including an anchor rod 1. Multiple spiral anchor discs 3 are installed at the lower section of the anchor rod 1, and a flange 2 is installed at the top of the anchor rod 1. A steel cylinder 5 is installed on the anchor rod 1, located between the flange 2 and the uppermost spiral anchor disc 3. The anchor rod 1 penetrates the steel cylinder 5 from top to bottom and is coaxial with the central axis of the steel cylinder 5. The steel cylinder 5 is a hollow and closed structure, and the bottom surface of the steel cylinder 5 has a spiral anchor disc 4 with a diameter larger than the outer diameter of the cylinder body.

[0018] This composite foundation is suitable for applications with low loads and is relatively small in size. It can be designed and constructed using a fully prefabricated method, with the following steps:

[0019] A large-diameter spiral anchor plate 24 is welded to the upper part of anchor rod 1, and a short steel cylindrical pile with an upper sealed end is welded to the upper part of spiral anchor plate 24. During construction, since the soil in the upper part of the foundation is relatively soft, the short steel cylindrical pile can be drilled into the soil along with spiral anchor plate 24, without the need for excavation and concrete pouring. The construction speed is fast, the efficiency is high, and the environmental protection effect is good.

[0020] The table below compares the data of the fully prefabricated short pile-spiral anchor composite foundation with that of cast-in-place piles and pile cap spiral anchors. From the data, we can see that the fully prefabricated short pile-spiral anchor composite foundation has the advantages of small size, low material consumption, and convenient construction.

[0021] Example 2

[0022] like Figure 2 As shown, this embodiment proposes a prefabricated short pile-spiral anchor composite foundation, including an anchor rod 1, with multiple spiral anchor discs 3 installed at the lower section of the anchor rod 1, and a flange 2 installed at the top of the anchor rod 1. A steel cylinder 5 is installed on the anchor rod 1, located between the flange 2 and the uppermost spiral anchor disc 3. The anchor rod 1 passes through the steel cylinder 5 from top to bottom and is coaxial with the central axis of the steel cylinder 5. The steel cylinder 5 is a hollow structure with open upper and lower ends, and the space between the inner wall of the steel cylinder 5 and the anchor rod 1 is filled with concrete to form a short column.

[0023] This composite foundation is suitable for situations with large loads. The upper short piles can be prefabricated or cast-in-place. The steps are as follows:

[0024] S01. Place the cylindrical steel cylinder 5, which is open at both the top and bottom, on the foundation surface;

[0025] S02. Use a large-diameter spiral drill bit to drill a hole downwards inside the steel cylinder 5;

[0026] S03. Press the steel cylinder 5 downward into the foundation (because the soil above the foundation is relatively soft, and after the hole is drilled inside the steel cylinder 5, only a thin soil wall remains between the side wall of the hole and the side wall of the steel cylinder 5, so the steel cylinder 5 can be easily pressed in).

[0027] S04. Clean the debris from the hole;

[0028] S04. Drill the helical anchor foundation into the hole;

[0029] S05. Pouring concrete or placing precast concrete blocks 6;

[0030] During concrete pouring, the steel cylinder 5 and the anchor rod 1 are connected and fixed by the poured concrete.

[0031] When using precast concrete blocks 6, the precast concrete blocks 6 can be bonded and fixed to each other and to the anchor rods 1 by injecting mortar or adhesive of the same strength.

[0032] The table below compares the data of the prefabricated short pile-spiral anchor composite foundation with that of cast-in-place piles and pile cap spiral anchors. From the data, we can see that the prefabricated short pile-spiral anchor composite foundation has the advantages of small size, low material consumption, and convenient construction.

[0033]

[0034] The above embodiments are only used to explain the concept of the present invention, and are not intended to limit the protection of the present invention. Any non-substantial modifications made to the present invention using this concept should fall within the protection scope of the present invention.

Claims

1. A prefabricated short pile-spiral anchor composite foundation, comprising an anchor rod, wherein a plurality of spiral anchor discs are provided on the lower section of the anchor rod, and a flange is provided on the top of the anchor rod, characterized in that, The anchor rod is equipped with a steel cylinder, which is located between the flange and the uppermost spiral anchor plate. The anchor rod passes through the steel cylinder from top to bottom and is coaxial with the central axis of the steel cylinder.

2. The prefabricated short pile-spiral anchor composite foundation as described in claim 1, characterized in that, The first form of the steel cylinder is a hollow and closed structure, with the bottom surface of the steel cylinder being a spiral anchor plate with a diameter larger than the outer diameter of the cylinder body.

3. The prefabricated short pile-spiral anchor composite foundation as described in claim 1, characterized in that, The second form of the steel cylinder is a hollow structure with openings at both the top and bottom, and the space between the inner wall of the steel cylinder and the anchor rod is filled with concrete.

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