JP2551136B2 - Steel tower foundation structure using screw anchors - Google Patents

Description

TECHNICAL FIELD The present invention relates to a steel tower foundation structure for embedding a screw anchor in a foundation part of a steel tower and installing the steel tower legs by using the anchor as a floor. is there.

[Prior Art] When constructing a steel tower, it is usual to drive concrete into the ground by using reinforcing bars and to mount the steel tower main legs on the basis of the concrete. In a specific area where the soil is soft and the geology is unstable, a screw anchor 10 having a screw at the tip as shown in FIG. 5 is buried in the ground from the ground GL, and the floor is placed on the head of the screw anchor 10. A method is used in which board steel is welded and the tower main landing gear is attached to it.

[Problems to be Solved by the Invention] In the steel tower foundation structure using the conventional screw anchor, there is a work of welding a floor steel material, and a welder is forced to perform a welding work in an upward unstable posture. Not only does this require a high degree of skill, but there is a concern that unevenness may occur at the joint, which is a problem.

In addition, in the conventional embedding of the screw anchor, 1
Since the screw anchor of the book is screwed in by a screwing machine, and the screw anchor is buried in the ground while sequentially connecting tor tubes of a predetermined length as described later, the screw anchor gradually becomes longer. When a rotational torque for screwing is applied to this, the reaction of the rotation acts on the hydraulic motor for screwing, the boom that suspends this, or the built-in leader, which causes screwing loss. In addition, there is a problem that a large machine is required to affect the strength of the boom and the leader.

That is, to explain this with a concrete example, when the screw part and the tube are connected, the length is usually 5 m or more, and a truck crane or the like having a boom of 6 m or more is required to mount the hydraulic motor and lift it. Besides, not only consideration of the above strength is required,
When attempting to screw the anchor onto the surface of the earth, a deviation may occur due to the reaction of the above-mentioned rotation, which may cause a hole deviation. Moreover, when the screw anchor driving holes are not vertical but oblique, the hole misalignment becomes aggravated and the topsoil is roughened and the working environment deteriorates, as well as the subsequent anchor screwing and girder. There is also a possibility that the work of mounting the steel material will be hindered.

Further, as shown in the lower left of FIG. 4, the conventional screw anchor 10 has a single screw anchor 10 centered around the screw anchor 10.
It is installed like a book, four in the first frame, eight in the second frame, and further in the third frame. As shown by the arrows in the figure, the screw anchors are installed in the direction of the four sides of the leg 21. There is also a problem that the corner overhangs and it is necessary to secure a large site for the steel tower 20. Moreover, when the steel material to be a girder is attached to the screw anchors 10 and 10 which are buried as in the conventional example in the lower left of FIG. 4, the lengths are not uniform and it is difficult to procure, and the intersecting crosses Since the above-mentioned welding concentrates on the piles and pile mounting parts and the difficult technique of upward welding is forced as already explained, it cannot be said that there is concern about reliability.

The object of the present invention is to solve the problems of the prior art as described above, and to make the screw anchor arrangement not a single arrangement as described above but a pair of screw anchors as a unit anchor, whereby the minimum required tower tower In order to provide a steel tower foundation structure using a screw anchor that can be installed very efficiently at the position of the screw anchor, and the girder material attached to this can also be installed in a very stable state and without relying only on welding. Is.

[Means for Solving the Problems] In the present invention, a pair of screw anchors and a supporting member bridging the screw anchors are used as a unit anchor, and a plurality of the unit anchors are embedded in the ground for each tower tower to support the bridge. A girder material for supporting the steel tower is fixed between the members in a crosswise manner, and the installation direction of the girder material is substantially diagonal to the steel tower.

[Operation] If a pair of screw anchors are used as unit anchors and they are bridged by a bridge support member, it becomes a bridge girder in the so-called buried state, and a girder material for supporting the steel tower is fixed by passing it over. Since it is easy to support and fix it, it is possible to arrange the girders almost diagonally on the steel tower floor just by arranging the unit anchors in the shape of a bridge girder, and occupy the area occupied by these building materials for each leg. It can be reduced efficiently.

[Examples] Hereinafter, the present invention will be described with reference to examples drawings.

FIG. 1 shows eight pairs of screw anchors 1 according to the present invention for each leg 21 provided at the four corners of the steel tower 20 as shown in FIG.
FIG. 2 is a plan view showing a specific state in which the girder members 13, 13 are supported and fixed using 0, 10, and FIG. 2 is an explanatory front view showing a specific configuration of the screw anchors 10, 10 installed as described above. , FIG. 3 is a plan view thereof.

In the present invention, the screw anchor 10, 10 is
The pair constitutes a unit anchor, and for example, binding bolts 12 and 12 are formed by a bridging support member 11 in the shape of a tightening band as shown in FIG.
It is fixed by tightening and is bridge-supported in the shape of a bridge as shown in the figure.

FIG. 5 shows a pair of screw anchors 10,1 as described above.
It is explanatory drawing which shows a mode that 0 is screwed in from the ground GL into the ground.

The boom 30 lifts the hoisting frame 31 as shown in the figure, and for example, hydraulic motors 32, 32 that can rotate independently are attached to the hoisting frame 31, and the screw anchors 10, 10 are installed next to each other in parallel at one end as shown in the figure. Support the hydraulic hose 3
The hydraulic motor 32 is operated by feeding the hydraulic pressure by means of 3, and the screw anchor 10 is rotated and screwed toward the ground from the ground surface.

At this time, the hydraulic motors 32, 32 are rotated in opposite directions to each other so that the screw anchors 1 adjacent to each other as shown in FIG.
It gives 0,10 the opposite rotation. By doing this, the rotation torque P and the rotation torque of the adjacent screw anchor are increased.
P ⁻ is in a state where they cancel each other out, and the reaction caused by rotating the screw anchor 10 is greatly reduced. The abnormal force generated by the reaction of is greatly reduced. Therefore,
The screw anchor 10 is stably screwed in, the risk of a hole shift or the like is greatly reduced, and the problem of strength exerted on the tool is significantly reduced.

The pair of screw anchors 10 and 10 are embedded as described above, and the embedded screw anchors 10 and 10 are supported and fixed by the bridge supporting member 11 as shown in FIGS. On the support member, as shown in FIG. 1, the girder materials 13, 13 are installed in a cross shape as shown in the figure so that they are substantially in the diagonal direction of the steel tower, and as shown in FIGS. A hook bolt 14 is provided between the beam member 13 and the bridge supporting member.
The steel tower foundation structure according to the present invention is completed by firmly fixing the steel tower.

In this case, if bolt holes 15, 15 having a certain degree of freedom in the girder material 13 are formed in advance along the longitudinal direction of the girder material 13 as shown in FIG. It is possible to prepare the girder material as a general-purpose material to some extent according to the installation interval.

With the above configuration, the number of screw anchors is 8
In the case of a book, one frame can be arranged as shown in FIG. 4, and in the case of 16 lines as shown in FIG. 1, one frame and two frames are sufficient. Not only can it be made more compact, but the direction in which the screw anchors extend increases along the diagonal direction of each leg, greatly improving the utilization efficiency of each leg area compared to the conventional example shown in the lower left of FIG. 4 described above. There is a merit to get.

When screwing the screw anchor 10 into the ground, as described above with reference to FIG. 5, the first stage torque tube 3 is connected to the screw shaft 1 to form the screw anchor 10.
Although this is rotated and screwed into the ground, as explained above, the length of the screw anchor 10 that connects the torque tube of the first stage in this way is about 5 m, which is considerably long. It requires a great deal of careful work to screw the vertical into the ground.

When the screw anchor 10 is screwed in, if the first stable screwing of the screw shaft 1 is achieved, the subsequent torque tube 3 can be stably screwed in. Therefore, when the screw shaft 1 is first screwed in, as shown in FIG.
Instead of connecting, the auxiliary cap 7 having the same shape as the torque tube as shown in FIG. 7 and having a short length is connected, and the short screw shaft 1 as a whole is first screwed in stably to complete the screwing. After that, if the auxiliary cap 7 is removed and the torque tube 3 is connected, relatively easy and stable screw-in of the screw anchor 10 can be achieved.

Also, the stone is bitten first crevice of the screw blade 2 ₁ shown in FIG. 7 when Komu twisting the screw shaft, there may become impossible narrowing twisting idling. To prevent such a situation, as shown in the front view in one-dot chain line circle of FIG. 7 (a) and a plan view (b), shifting the diameter of the first screw blade 2 ₁ of the upper side slightly If the step G is formed in the radial direction between the end of the blade on the leading end side and the end of the trailing end at the screw pitch P, the first screw blade
The cracked part in the screw pitch of 2 ₁ can be made large, and the situation in which a stone is bitten and idle can be greatly reduced.

On the other hand, the torque tubes 3 and 3 are those whose diameter and length are determined in consideration of the geology in which the screw anchor is buried and the shape and verticality of the steel tower supported by the screw anchor, and are usually plural. A fixed length torque tube 3 is connected and buried. In this case, in the conventional case, as shown in FIG.
However, an enormous portion of the outer diameter is generated in the coupling 6 part, and resistance is generated in the coupling 6 part when it is buried in the ground in such a state that the outer diameter is different. Absent.

As shown in FIG. 9, in one torque tube 3 to be connected, a fitting hole 4 (the fitting hole is formed in a polygonal shape,
It is desirable to configure so that rotation in the connection hole does not occur in the connected state).

As shown in FIG. 8 (a), the torque tube 3 connected to face the torque tube 3 having the fitting hole 4 is fitted into the fitting hole 4 properly. A connecting portion piece 5 to be obtained is formed in a projecting manner, and a spring-type locking piece 5a such as a tulip-like spring piece is formed at the tip portion thereof.
When the coupling piece 5 is fitted into the fitting hole 4, the spring-loaded spring-loaded locking piece 5a is displaced inward so that the fitting piece 4 can easily pass through. On the other hand, after it has passed through the fitting hole 4, the spring type locking piece 5a returns to its original position by the spring bias, and the fitting hole 4 is completely locked as shown in FIG. 8 (b). Therefore, both torque tubes 3 and 3 are configured so that they can be completely connected.

If the torque tubes 3 and 3 are internally connected in this way, unlike the case where the coupling 6 shown in FIG. 10 is used, there is no enlarged portion on the outer surface of the torque tube. The fear that the resistance will increase when screwing in is eliminated.

[Advantages of the Invention] As described above, according to the present invention, the construction of the steel tower foundation using the screw anchors can be more easily and stabilized, and the reliability can be greatly improved. It has a great effect on the world.

[Brief description of drawings]

FIG. 1 is a plan view showing a concrete structure of a steel tower foundation according to the present invention for each leg, FIG. 2 is a front view showing an embodiment of a screw anchor used in FIG. 1, and FIG. 3 is a plan view thereof. ,
FIG. 4 is an explanatory plan view showing a comparison between the present invention and a conventional example for each leg in a steel tower, FIG. 5 is an explanatory view showing a screw anchor screwing state according to an embodiment of the present invention, and FIG. Fig. 7 is an explanatory view showing a rotation state of the screw anchor, Fig. 7 is an explanatory view showing a state in which a cap is attached to the screw shaft according to the embodiment of the present invention, and Fig. 8 is a torque tube according to the embodiment of the present invention. FIG. 9 is a plan view showing an example of a fitting hole, and FIG. 10 is an explanatory view showing a conventional connection state of a torque tube. 1: Screw shaft, 2 ₁ , 2 ₂ , 2, ₃ : Blade, 3: Torque tube, 4: Fitting hole, 5: Connecting piece, 5a: Spring type locking piece, 7: Auxiliary cap, 10: Screw anchor , 11: Bridge support member, 12: Binding bolt, 13: Girder material, 14: Hook bolt, 15: Bolt hole, 21: By leg, 30: Boom, 31: Lifting frame, 32: Hydraulic motor, 33: Hydraulic hose.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-272815 (JP, A) JP-A-51-102310 (JP, A) Actually opened 60-120033 (JP, U) Actually opened 62- 143741 (JP, U) Actually opened 50-142310 (JP, U)

Claims (1)

(57) [Claims] 1. A unit anchor comprising a pair of screw anchors and a support member bridging the screw anchors, and a plurality of the unit anchors are buried in the ground for each tower tower leg to support the steel tower between the bridge support members. A steel tower foundation structure using a screw anchor configured such that the girder material is fixed by passing it over and the installation direction of the girder material is substantially diagonal to the tower tower.