JPH02232427A - Pylon foundation structure by use of screw anchor and screwing method for screw anchor and its screw and torque tube - Google Patents

Abstract

PURPOSE:To stabilize simply a structure, by positioning a plurality of unit anchors in a ground every leg of pylon, and arranging the installation direction of a beam laying between connecting supports of anchors to turn them in the nearly diagonal direction of the steel pylon area. CONSTITUTION:A unit anchor is constitute as a bridge with fastened bolts 12 of a couple of screw anchors 10, 10 with a supporting member 11. Next, beams 13, 13 are laid at right angles to turn in the nearly diagonal direction of the pylon area by use of four couples of unit anchors at the respective legs 21 installed in the four corners of the pylon area and fixed by a hook bolt 14 between the beam 13 and the member 11. The rotary torque is counter balanced each other by mutually reverse revolution of the screw anchors 10 to reduce the effect resulting from screwing reaction. Therefore, the construction of foundation can be simply stabilized.

Description

[Detailed Description of the Invention] [Industrial Application Field 1] The present invention relates to a steel tower foundation top support for embedding screw anchors in the base portion of a steel tower and using it as a floor rock to attach the steel tower legs when the steel tower is erected; This article relates to the screwing method for burying the screw anchor underground, as well as the screw and torque tube used for the screw anchor. [Conventional technology] When constructing a steel tower, it is common practice to place reinforcing bars into the ground, pour concrete into the ground, and install the main legs of the tower using this as a foundation. In certain areas where the ground is soft and the geology is unstable, a screw anger 10 having a screw at the tip as shown in Fig. 5 is buried underground from the ground GL.
The floor is on the head of the screw anchor 10! ! The method used is to weld the steel material and attach the main legs of the steel tower to these parts.
Section U that the invention seeks to solve] In the above-mentioned conventional tower foundation construction using screw anchors, there is work to weld the floor plate steel, and the welder is forced to weld in an unstable upward position. Not only does it require a high level of skill, but there is also the risk of uneven joints, which is a problem. As described below, the anchor is buried underground by sequentially connecting torque tubes of a predetermined length, so 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 lifts it, the erection leader, etc., resulting in screwing loss. On top of that, there is a problem in that a large machine is required because it affects the strength of the boom and rieter.To explain this with a concrete example, if a part of the screw is connected to the tube, the length is usually 5 m. In order to attach a hydraulic motor to the surplus and lift it, a truck crane with a boom of 6 m or more is required.Not only does it require consideration of the above-mentioned strength, but it also requires the anchor to be placed on the ground. When trying to screw in, there is a high possibility that the above-mentioned rotational reaction will cause misalignment and cause hole misalignment.Furthermore, if the hole to be driven by the Scrunian force is not perpendicular but oblique, the above-mentioned hole Not only will the misalignment become severe and the topsoil will be disturbed, resulting in a poor working environment, but there is also the risk of interfering with the subsequent work of screwing in the anchors and installing the steel materials that will become the girders. Furthermore, the conventional screw anchor 10 has a single screw anchor 10, one in the center, four in the first frame, and two in the second frame, as shown in the lower left of Fig. 4.
There are eight in the frame, and a third frame, and so on.
There is also the problem that the corners of the screw anchor protrude in the direction of the four sides of the leg section 21 as shown by the arrows in the figure, and it is necessary to secure a wide site for the steel tower base 20. Moreover, when installing steel members to serve as girders to the screw anchors 10, 10, which are buried as shown in the conventional example shown in the lower left of Fig. The purpose of the present invention is to The above-mentioned problems of the conventional technology are solved, and instead of arranging the screw anchors individually as described above, a pair of screw anchors is used as a unit anchor, and thereby the screw anchors are installed at the minimum necessary position of the number of steel towers. A method for building the foundations of steel towers using screw anchors that can be arranged very efficiently and in a very stable condition for the girder materials to be attached, and that can be attached without any problems, and the screwing of such anchors. The present invention attempts to provide a method and a screw and torque tube for a screw anchor used in the method. [Means for Solving the Problems J] The present invention firstly consists of a pair of screw anchors and a supporting member bridging the screw anchors as a unit anchor, and a plurality of the Jjl anchors are buried in the ground for each tower leg. The girder material that supports the steel tower is passed and fixed between the bridge support members, and the crotch of the girder material is fixed! It is constructed so that the direction is approximately diagonal to the number of steel towers.Secondly, when FJlm the pair of screw anchors, they are screwed while being rotated in opposite directions in a parallel state. Thirdly, an auxiliary cap is used to ensure stable screwing of the screw shaft.Furthermore, fourthly, the rotation radius of the screw blade is the most advanced screw for screw anchors. A step is formed in the direction to prevent problems caused by stones getting caught in the blade.Fifth, the torque tube does not use the conventional coupling type connection, but is fitted inside one tube. By forming a hole and locking a spring-type locking piece provided on the other tube through the fitting hole, the tubes are connected inside, and a bulge is created on the outer diameter of the torque tube after the connection. [Function 1] If a pair of screw anchors is used as a unit anchor and these are bridged by a bridge support member, it becomes like a bridge girder when buried, and a steel tower can be supported by it. It is very easy to support and fix the girders because all you have to do is to cross and fix the girder materials for the steel tower.In addition, by simply arranging the unit unloading force in the shape of a bridge girder, the girder materials can be placed almost diagonally along the tower sill. The area occupied by these elliptical building materials for each leg can be efficiently reduced. Additionally, if a pair of screw anchors are rotated in opposite directions, the rotational torques will cancel each other out, and the torque on the screwing tool due to the reaction will be greater than when screwing a single screw anchor. The specific effects on the structure of the pond, which greatly reduce the impact, will be explained below. [Example] The present invention will be explained below with reference to actual drawings. Fig. 1 shows four legs 21 according to the present invention provided at the four corners of a steel tower numbering 20, as shown in Fig. 4. FIG. 2 is a plan view showing a concrete state in which girder members 13, 13 are supported and fixed using a pair of screw anchors 10.10, and FIG. 2 shows a concrete configuration of the screw anchors 10.10 installed as described above. The explanatory front view shown in FIG. 3 is a plan view thereof.

In the invention, a pair of screw and anchors 10, 10 constitute a unit anchor, and a fastening bolt 12, 12 is held by a bridge support member 11 in the form of a tightening band as shown in FIG. It is tightened and fixed, and supported in the form of a girder as shown in the figure. FIG. 5 is an explanatory diagram showing how the pair of screw unloading forces 10.10 are screwed into the ground from the ground GL as described above. The lifting frame 31 is lifted by the boom 30 as shown in the figure,
For example, hydraulic motors 32 and 32, which can rotate independently, are attached to the lifting rack ellipse 31, and screw anchors 10 and 10 are supported at one end in parallel to each other as shown in the figure, and hydraulic pressure is sent through a hydraulic hose 33. By doing so, the hydraulic motor 32 is operated, and the screw anchor 10 is rotated and screwed into the ground from the ground surface. At this time, the hydraulic motors 32, 32 are rotated in opposite directions, and the screw anchors 10, which are installed next to each other, are rotated as shown in FIG.
, 10 are rotated in the opposite direction. In this way, the rotating torque P and the rotating torque P' of the adjacent screw anchor cancel each other out. As a result, the reaction force generated when the screw anchor 10 is rotated is reduced by a factor of 11, and the abnormal force generated by the reaction force of the rotational torque as seen when twisting a single screw anchor described above is greatly reduced. Therefore, the twisting of the screw anchor 10 is stabilized,
The risk of hole misalignment is greatly reduced, and problems with the strength of the tool are also greatly alleviated. After burying a pair of screw anchors 1010 as described above and supporting and fixing these buried screw anchors 10, 10 with the bridging support member 11 as shown in FIGS. 2 and 3, this bridging support member -L,
As shown in FIG. 1, the girder 13.1. ．． 3 are installed in a crosswise manner as shown in the figure so as to be approximately diagonal to the pylon sill, and as shown in FIGS. Once firmly fixed, the steel tower foundation structure according to the present invention is completed.
In this case, if bolt holes 15.15 with a certain degree of freedom are formed in the girder l3 along the longitudinal direction of the girder l3 as shown in FIG.
, 10. Depending on the installation interval, girder material can be used as a somewhat general purpose material. If the tank is configured as described above, if the number of screw anchors is 8, it can be arranged in one frame as shown in the upper right of Figure 4, and if there are 16 screw anchors as shown in Figure 1 below, 1 frame and 2
Not only can the overall configuration be made more compact than the conventional example, but also the direction in which the increasing number of screw anchors extends is in the diagonal direction of each leg, compared to the conventional example shown in the lower left of Fig. 4 mentioned above. This has the advantage of greatly improving the utilization efficiency of the area for each leg. When screwing the screw anchor 10 into the ground, connect the first stage torque tube 3 to the screw shaft 1 as explained above in FIG. As explained earlier, the length of the screw anchor 10 connected to the first stage torque tube is quite long, around 5 m, and it is twisted vertically into the ground. When screwing in the screw anchor 10, once the first screw shaft 1 has been screwed in stably, the only thing left to do is to screw in the subsequent torque tube 3 in a stable manner. Therefore, when first screwing in this screw shaft, instead of connecting the first stage torque tube 3 as shown in FIG. Connect an auxiliary cap 7 that has the same shape as the tube and is short, and first stably screw in the screw shaft 1, which is short as a whole. After the screwing is completed, remove the auxiliary cap 7 and remove the torque tube. By connecting the screws 3 to 3, it is possible to achieve a relatively easy and stable screw unscrewing force of 10. Also, when tightening the screw shaft, the seventh
In some cases, stones were caught in the cracks of the first screw blade 21 shown in the figure, causing it to spin idly and become impossible to screw in. In order to prevent such a situation, as shown in the front view (a) and plan view (b) inside the dot-dashed line circle in FIG. If a step G is formed in the radial direction between the end of the blade on the forward @ side and the end on the rear end side in the screw bitch P, the gap in the screw pitch of the first screw blade 21 The parts can now be made larger, and the occurrence of idling due to biting of stones can be reduced. on the other hand,
The diameter and length of the torque tube 3.3 is determined by considering the geology in which the screw anchor is buried and the shape and weight of the steel tower supported by the screw anchor, and is usually made of multiple fixed lengths. The torque tube 3 is connected t1. It will be buried. In this case, conventionally, as shown in FIG. 10, the trunk tube 3.
3 were connected together, but the coupling 6 part would have a huge part of the outer diameter, and when buried in the ground with different outer diameters, this coupling 6 part would create resistance, which is not preferable. In the present invention, as shown in FIG. 9, a fitting hole 4 (this fitting hole is formed in a polygonal shape and inserted into the connecting hole in the connected state) The torque tube 3 is connected facing the torque tube 3 having the fitting hole 4 formed in this way. As shown in FIG. 8(a), a connecting piece that can be fit snugly into the fitting hole 4 is formed protrudingly, and a spring piece such as a tulip-shaped spring piece is attached to the tip end of the connecting piece. A locking piece 5a is provided, and when the connecting piece 5 is fitted into the fitting hole 4, the spring-loaded locking piece 5a is displaced inward to facilitate fitting. The spring t is formed horizontally so that it can pass through the hole 4, and after passing through the fitting hole 4,
The spring-type locking piece 5a returns to its original position by one force, as shown in Fig. 8 (
As shown in b), it is completely engaged with the fitting hole 4, and both torque tubes 3 and 3 are thereby completely connected.
It is composed of functions. If the torque tubes 3 and 3 are connected internally in this way, unlike the case where the coupling 6 shown in FIG. 10 is used, there is no large part on the outer surface of the torque tube. This eliminates the risk of increased resistance when twisting. [Effects of the Invention] As described above, according to the present invention, the construction of a steel tower foundation using screw anchors can be made easier and more stable, and it can contribute to the improvement of reliability in the following points. The effect it has on this world is enormous.

[Brief explanation of the drawing]

Fig. 1 is a plan view showing the specific configuration of each leg of a steel tower foundation according to the present invention, Fig. 2 is an explanatory front view of an embodiment of the 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 sill, Fig. 5 is an explanatory view showing a screw anchor twisting situation according to the present invention, and Fig. 6 is an explanatory view showing a screw anchor in that case. FIG. 7 is an explanatory diagram showing the state of rotation of the anchor, FIG. 7 is an explanatory diagram showing how the cap according to the present invention is attached to the screw shaft according to the present invention, and FIG. 8 is an explanatory diagram showing the state of connection of the torque tube according to 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 torque tubes. 1: Screw shaft, 21, 22. 23 + blade, 3: torque tube, 4: fitting hole, 5: connecting piece, 5a: spring type locking piece, 7: auxiliary cap, 10: screw anchor, 1 1: 1 2: 1 3: 1 4 : 1 5 : 2 1 : 3 0 : 3 1 : 32 ; 3 3 : Bridge support members, binding bolts, girder materials, hook bolts, bolt holes, separate legs, boom, side of lifting rack, hydraulic motor, hydraulic hose. Figure 2 Figure 1 +1

Claims (5)

[Claims] (1) A unit anchor consists of a pair of screw anchors and a support member that bridges them, and a plurality of the unit anchors are buried in the ground for each tower leg, and a girder that supports the tower between the bridge support members. A steel tower foundation structure using screw anchors, which is constructed so that the girder members are fixed across each other and the installation direction of the girder members is approximately diagonal to the tower sill. (2) Place a pair of screw anchors side by side in parallel,
A screw anchor screwing method in which both screw anchors are screwed into the ground and buried while rotating in opposite directions. (3) When tightening a screw anchor, connect a short auxiliary cap to the screw shaft, first screw the screw shaft into the ground, then remove the auxiliary cap, connect the torque tube, and screw it in. How to screw it in. (4) In a screw anchor that is buried underground with a screw installed at the tip and a torque tube sequentially connected to the rear thereof, at least the most advanced blade of the screw is attached in the rotational radial direction to the rotational tip side and the rear end side. A screw for a screw anchor formed by forming a step. (5) In a screw anchor that is installed in the ground with a screw installed at the tip and sequentially connected with torque tubes behind it, a fitting hole is formed in one tube of the connection part, and a fitting hole is formed in the other tube side. A connecting piece that fits snugly into the fitting hole is provided, and the tip of the connecting piece is configured to be able to be displaced inwardly and pass through the fitting hole when passing through the fitting hole, and the connecting piece is configured to be able to pass through the fitting hole. A torque tube for a screw anchor is provided with a spring-type locking piece that returns to its displacement and locks in the fitting hole when both tubes are connected through the hole.