JP4600164B2 - Steel tower reinforcement method - Google Patents

Description

  The present invention relates to a technique for reinforcing steel tower members that constitute a power transmission tower, a communication tower, and the like.

  When an earthquake or land subsidence occurs, the ground collapses or fluctuates at the location of the steel tower. As a result, if the four-legged foundation is not integrated, the steel tower foundation will be displaced indefinitely, resulting in secondary stress on the steel tower members. May occur and the member may be deformed. In addition, the member may be deformed by other natural external forces. For example, when an external force exceeding the design load is applied due to a strong wind due to a typhoon or an abnormal snowfall phenomenon, the member may be deformed. Under these circumstances, the degree of foundation displacement and the deformation state of the member are confirmed, and after checking whether a predetermined required strength can be ensured, member replacement and member reinforcement are performed.

  When exchanging members, it is common to remove the deformed member and replace it with the same newly manufactured member. In this case, secondary stress is applied to the deformable member due to the uneven displacement of the foundation, but it may be impossible to remove the member because it is difficult to quantitatively grasp how much it is. . Furthermore, there is a risk that removing the member increases the displacement of the foundation and the deformation of the member. Therefore, in order to prevent the displacement of the foundation and the deformation of the members from progressing, it was necessary to take measures such as connecting the four legs of the steel tower with beams and preventing the legs from relatively deforming.

  In addition, when reinforcing members, the structure at the joints between the members tends to become complicated, and the design and construction tend to be complicated. In addition, it is necessary to remove the bolts at the joints in order to attach the reinforcement members. There are many cases. Removing the deformed member has a risk of increasing the displacement of the foundation and the deformation of the member, and a large machine such as a hydraulic jack must be used as a support jig.

  Depending on the degree of foundation displacement, residual secondary stress in the steel tower member cannot be denied. Even when measures are taken to connect the legs with beams, when the members are replaced or reinforced, the member must be removed (including unscrewing the joint points), and the secondary stress is redistributed to other members. Therefore, in order to ensure safety during construction when replacing or reinforcing, it is necessary to devise by using a support jig.

  In other words, since the members affected by non-uniform displacement also contribute to the stress transmission, they cannot be removed easily, and it is necessary to add a substitute function for stress transmission in advance and safely replace or reinforce them. is there. The existing technology has a method of ensuring safety by using a large machine, but has a problem that the economic burden is large.

  Therefore, the subject of this invention is providing the reinforcement technique of the tower member which can implement replacement | exchange and reinforcement of a tower member safely and economically.

In order to solve the above problems, the present invention employs the following method.
The present invention is a steel tower reinforcement method in which the reinforcement target portion of the steel tower includes a member constituting the steel tower and a joint portion to which the member is bolted, and the first step of welding and joining the member and the member in the joint part; A second step of removing a welded member and a bolt that joins the member, a third step of attaching a reinforcing plate to the member in the joint portion, and a reinforcing material of the member to be reinforced by bolting to the reinforcing plate And a fourth step.

  According to the present invention, after a member and a member in a joint portion are welded to ensure stress transmission, a reinforcing plate which is a stress transmission member between the member and the member is attached to the member in the joint portion, and the reinforcing plate Since the method of bolt-joining the member and the member is adopted, the reinforcement construction method does not break the structure of the joint and the mechanism of stress transmission. Accordingly, there is no need to provide a beam for connecting the four legs of the steel tower or to use a large machine as an auxiliary member as in the prior art. Therefore, replacement and reinforcement of steel tower members can be performed safely and economically. it can. Thereby, even when the transportation means of goods is limited as in a mountainous area, construction can be performed without using large-scale equipment, which is economically advantageous over existing methods.

  In the present invention, in the portion to be reinforced, when the member and the member are bolted in a form sandwiching an existing mounting plate, in the first step, by welding the mounting plate to the member to be reinforced, It is desirable to join the members. If it does in this way, the existing attachment plate can be used effectively as a stress transmission structure.

  In this invention, it is desirable to perform the member reinforcement process which provides the reinforcement material attached to the member of the said reinforcement object part after the said 3rd process or the 4th process. In the third step, since the reinforcing plate, which is a stress transmission member, is already attached to the member in the joint, it becomes possible to easily attach the reinforcing material, which becomes the additional stress material, in the construction procedure via this reinforcing plate. Because.

  The member to be reinforced is a main pillar material that is a stress material constituting a steel tower and a stress material other than the main pillar material, and in the third step, the reinforcing plate is preferably attached to the main pillar material. . In this way, when a reinforcing plate is attached to the main pillar material, a plurality of stress materials and auxiliary materials including reinforcing stress materials (reinforcing materials) are integrally joined to the main pillar material via the reinforcing plate. can do.

  In the case where the member to be reinforced is a main pillar material made of an angle material, it is desirable that the reinforcing material is provided in a form of being reinforced by overlapping on the inner surface or outer surface side of the main pillar material to be reinforced after the fourth step. This is because the step of reinforcing the stress material other than the main pillar material can be completed in the fourth step, and the step of providing the reinforcing material (reinforcing main pillar material) can be easily performed thereafter. It is because the influence on the structural eccentricity can be reduced by further reinforcing the layers.

  In the present invention, in the reinforcement target portion, when another member is joined to the inner surface or outer surface side of the main pillar material to be reinforced, the reinforcing material can be joined to the inner surface or outer surface of the main pillar material to be reinforced. It is desirable to perform a cutting step of cutting the tip portion of the other member. This is because, by performing this cutting step, mutual interference between members can be eliminated, and the construction of the reinforcing material can be performed easily and with high accuracy.

  According to the steel tower reinforcing method according to the present invention, replacement and reinforcement of steel tower members can be performed safely and economically.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing a framework of one leg of a four-legged power transmission tower. FIG. 2 is a reinforcing process diagram of a portion to be reinforced having a joint portion in which a stress material is bolted to the main pillar material. 3-6 is a reinforcement process figure of each corresponding member of the reinforcement object part. FIG. 7 is a diagram showing a determination flow of whether or not steel tower members need to be reinforced. FIG. 8 shows a structure before reinforcement of the portion to be reinforced, and FIG. 9 is a diagram showing a structure after reinforcement (an example in which a reinforcing main column member is provided outside). In the embodiment, an example will be described in which the present invention is applied to a steel tower constructed using an angle material as a steel tower component (main pillar material, belly material, horizontal material, auxiliary material).

(Judgment of necessity of steel tower member reinforcement)
In this embodiment, a basic determination method for determining whether or not a steel tower member needs reinforcement is performed based on the following criteria.
(1) A member deformed by a stress material is reinforced.
(2) Replace the member deformed by the buckling stiffener (auxiliary material) and the broken bolt. (3) Even if the stress material is not deformed, the steel tower having a large foundation displacement estimates the degree of bolt removal at the member joint and the acting stress associated with the foundation displacement, and determines the presence or absence of reinforcement according to the degree. Further, if it is determined that the applied stress exceeds the elastic limit even if the bolt is pulled out, stress materials other than the main column material are reinforced.
(4) Do not reinforce except the above.

  This determination method is shown in an easy-to-understand manner in FIG. First, in step S1, it is determined whether or not there is a leg displacement of the steel tower 1. If there is no leg displacement, no reinforcement is made.

  If there is a leg displacement, it is determined in S2 whether there is a member deformation. In the case of member deformation, reinforcement of a stress material, replacement of a buckling stiffener, etc. are performed in order to maintain the current framework state. In the case where there is no member deformation, the process proceeds to S3, and the joined state of the bolt (the degree of bolt removal) is confirmed. This is because even if there is no deformation of the member, there is a concern about an increase in stress due to the displacement, and therefore the presence or absence of the increased stress can be confirmed by the degree of removal of the bolt. If it is determined in S3 that the bolt cannot be removed, the stress material is reinforced. The reason is that it can be determined that the increased stress exists as an effect of the leg displacement.

  In S3, when a bolt can be removed easily, it progresses to S4 and a steel tower material influence check by a non-uniform displacement is implemented. For example, whether or not the material is in the elastic range is checked even when the stress at the time of an earthquake (when there is no wind and the increase in stress due to displacement) is taken into consideration. When there is a concern about material plastic deformation, the stress material is reinforced, and when there is no material plastic deformation concern, no reinforcement is made.

(Specific reinforcement method)
The concrete method of steel tower member reinforcement is illustrated below.
(1) The main pillar material is a reinforced structure, the belly material is a double angle, and the internode horizontal material is a double T material.
(2) The inter-joint horizontal member to be reinforced is not a single piece but separated at the center.
(3) Since the main pillar material is a joint between a single material and a laminated material, structural eccentricity is examined.
(4) When reinforcing members are reinforced by overlapping the existing main column material, it cannot be installed unless the joint bolts of the existing members are removed, so the joints of the existing main column material and the main column material and the abdomen / buckling stiffener The joint portion is welded so that a predetermined proof stress can be maintained even without a bolt.
(5) In principle, the joining bolts should have the current diameter and number.

(Example)
Next, a method for reinforcing each part of the portion to be reinforced will be specifically described with reference to FIG. 1 and FIGS. In the examples shown in these drawings, the reinforcement target portion 2 of the steel tower 1 is a bell material (upper belly material 4) and a horizontal material (internode horizontal material 5) with respect to the main pillar material 3 which is a stress material constituting the steel tower. ), An example suitable as a reinforcing method for a steel tower having a joint 7 to which an auxiliary material (oblique auxiliary material 6) is bolted. In addition, since the diagonal auxiliary material 6 is a buckling stiffening material, here, the abdominal material (upper abdominal material 4 and the lowermost abdominal material 4a) and the horizontal material (internode horizontal material 5) other than the main column material 3 are used. It is defined as a stress material. 5a is a horizontal auxiliary material.

  FIG. 2A is an enlarged view of the current joint portion 7 (portion A in FIG. 1) of the reinforcement target portion 2 of the tower 1, and FIG. The figure and the figure (c) are the enlarged views after completion of attachment plate replacement. FIG. 3 specifically illustrates the procedure for replacing the mounting plate at the joint 7 by a partial horizontal cross section in which the correspondence relationship with each member corresponds to the column and the process order corresponds to the row. 4, 5, and 6 show the upper belly material 4, the internode horizontal material 5, and the diagonal auxiliary material 6 in an enlarged manner in the order of steps.

  In the current joint 7, the end of the upper belly material 4 and the internode horizontal material 5, which are also angle materials, are provided on the inner surface side of the main pillar material 3 with respect to the main pillar material 3 made of the angle material. The ends of the diagonal auxiliary members 6 are joined (bolted) by bolts and nuts 8 on the outer surface side of the main column 3. Note that an existing mounting plate 9 that also serves as a stress transmission member is inserted and joined between the upper belly member 4 and the internode horizontal member 5 and the main pillar member 3. Therefore, the reinforcement process is performed from this current state.

  Here, since the diagonal auxiliary material 6 is a buckling stiffener, it can be removed. Accordingly, in the joint portion 7, first, as shown in FIGS. 4B and 5B, the main column member 3, the upper belly member 4, and the internode horizontal member 5 are joined by welding (first step). 1 step). At that time, since the mounting plate 9 exists, in this first step, the mounting plate 9 is welded to the main column member 3, the upper belly member 4 and the internode horizontal member 5, respectively. The material 4 and the internode horizontal material 5 are welded together. The oblique auxiliary material 6 is not welded as shown in FIG.

  At this time, about the internode horizontal material 5, a front-end | tip part is cut by on-site processing. For the upper belly material 4 and the diagonal auxiliary material 6, the distal end portion is cut after welding joining to the main column material 3 of a stress transmission plate (reinforcing plate) 10 described later (FIG. 4D, FIG. 6 ( d)). Moreover, about the upper belly material 4, the internode horizontal material 5, the diagonal auxiliary material 6, etc., the drilling process for a bolt stop is implemented in a required location. In the drilling process, holes for additional bolts 8b for attaching the stress transmission plate 10 to the main pillar 3 are also processed in the field. In addition, although not shown in particular in various field work etc. including this welding work, it implements after building a scaffold as needed.

  Next, as shown in FIGS. 4 (c), 5 (c) and 6 (c), the bolt which joins the welded main pillar material 3, the upper belly material 4 and the internode horizontal material 5 to each other. A process (second process) of removing the nut 8 and the bolt / nut 8 joining the main pillar material 3 and the diagonal auxiliary material 6 is performed. However, in this second step, as shown in FIGS. 4 (c) and 5 (c), the bolts 8a necessary for the mounting plate 9, the upper abdomen 4, the internode horizontal member 5 and the like are used. Leave it undrawn. That is, to temporarily fix the stress transmission plate 10 to the main column member 3 by insertion and removal including bolts that do not interfere when the stress transmission plate 10 of the next process is welded to the outer surface of the main column member 3 and bolts that are desired to remain. Keep the bolts that can be used without removing them.

  Next, a step of attaching the stress transmission plate 10 between the main column member 3, the upper belly member 4 and the internode horizontal member 5, including the diagonal auxiliary member 6, to the main column member 3 in the joint 7 (third step). )I do. As the stress transmission plate 10, a plate that is larger than the mounting plate 9 and formed substantially similar to the mounting plate 9 is used. Therefore, the stress transmission plate 10 also has a function as a mounting plate for each member.

In this third step, first, the stress transmission plate 10 is attached and fixed to the outer surface of the main column member 3 using the bolts / nuts 8, the retaining bolts 8a, the additional bolts 8b, etc. left in the second step. (Temporarily fixed). Thereafter, the stress transmission plate 10 is welded to the main column member 3. In this welding joining, as shown in FIG. 2, there are a welding downward portion 11, a welding lateral portion 12, and a welding upward portion 13. Since the welding upward portion 13 has a poor welding posture, the strength design is ensured by the welding downward portion 11 and the welding lateral portion 12.

  After the stress transmission plate 10 is welded and joined in this way, next, as shown in FIG. 5D, in the portion of the existing internode horizontal material 5 that is the member to be reinforced, the internode horizontal material 5 is attached. A new internode horizontal member 51 is added so as to form a double T (see FIG. 9 b view), the new internode horizontal member 51, the stress transmission plate 10, and the existing internode horizontal member 5. A step (fourth step) (stress material reinforcing step) in which the bolts and nuts 8 are integrally bolted together. At this time, the bolt joint is performed in a state where the end portion of the new internode horizontal member 51 is attached to the outer surface of the stress transmission plate 10. In addition, bolt bonding is performed in a state where a spacer 14 such as a washer is disposed in the gap between the new internode horizontal member 51 and the stress transmission plate 10.

  Further, as shown in FIG. 4 (e), in the upper abdomen 4 portion, the existing upper abdomen 4 with its end cut off and the stress transmission plate 10 are bolted together by bolts and nuts 8. Work to do. Further, bolt bonding is performed in a state where a spacer 14 such as a washer is disposed in the gap between the existing upper abdomen 4 and the stress transmission plate 10. If necessary, the upper abdomen 4 may be reinforced with a new upper abdomen so as to form a double T material.

  Further, as shown in FIG. 6D, in the portion of the diagonal auxiliary material 6, the existing diagonal auxiliary material 6 whose end is cut is attached to the outer surface of the stress transmission plate 10, and the stress transmission plate 10 and the diagonal auxiliary material 6 are oblique. The auxiliary material 6 is bolted together by bolts and nuts 8. In addition, you may replace the diagonal auxiliary material as needed.

  After completing the fourth step in this way, next, as shown in FIG. 4 (f), FIG. 5 (e), and FIG. 6 (e), a reinforcing main pillar that is attached (overlapped) to the inner surface of the main pillar material 3 The main pillar material reinforcement process for providing the material 31 is performed. In reinforcing the main pillar material, for example, as shown in FIGS. 1C and 1D, the joint is reinforced by welding in order to remove the bolt of the joint. Also in this case, since there are a welding downward portion, a welding lateral portion, and a welding upward portion, the welding upward portion has a strength design that does not expect welding strength. In addition, as shown in FIG. 1 (a), the main pillar material is a joint between a single material and a laminated material, so that consideration is given to structural eccentricity.

  In the embodiment shown in FIG. 9 (after reinforcement), the internode horizontal member 5 has a double T member reinforcement structure with a new internode horizontal member 51, and the diagonal auxiliary member 6 is replaced with a new diagonal auxiliary member 61. In the example shown, a double T-material reinforcing structure is provided by adding a new abdomen 41 to the lowermost abdomen 4a near the top of the foundation.

  FIG. 10 shows the main column member attachment part and the modification procedure of the buckling stiffener (auxiliary material). Since the horizontal auxiliary material 16 and the diagonal auxiliary material 17 which are the buckling stiffeners can be removed from the main pillar material 3, in this embodiment, from the current state shown in FIG. After cutting the ends of the horizontal auxiliary material 16 and the diagonal auxiliary material 17 as shown, a new stress transmission plate 18 is attached by welding and joining to the main pillar material 3 as shown in FIG. The bolt is joined to the diagonal auxiliary material 17. And as shown in the same figure (d), it is set as the reinforcement method which attaches the new reinforcement main pillar material 31 via the spacer 14 inside the main pillar material 3. As shown in FIG.

It is a schematic block diagram which shows one leg one surface among the 4-legged transmission line towers which concern on the Example of this invention. It is a reinforcement | strengthening process figure of the reinforcement object part which has the junction part by which the stress material was bolted with respect to the main pillar material which concerns on the Example of this invention. It is reinforcement process explanatory drawing of each corresponding member of the reinforcement object part which concerns on the Example of this invention. It is a reinforcement process expansion explanatory drawing of the upper belly material of FIG. 3, and the main pillar material part. It is a reinforcement process expansion explanatory drawing of the inter-node horizontal material and main pillar material part of FIG. It is a reinforcement process expansion explanatory drawing of the diagonal auxiliary | assistant material and main pillar material part of FIG. It is a figure which shows the determination flow of the necessity for steel tower member reinforcement. It is a figure which shows the structure before reinforcement of the reinforcement object part. It is a figure which shows the structure after the reinforcement of the part for reinforcement (example which provided the reinforcement main pillar material on the outer side). It is process drawing which shows the main pillar material attachment site | part and remodeling procedure of a buckling stiffener.

Explanation of symbols

1 Steel tower 2 Reinforcement target part 3 Main pillar material (stress material)
31 Reinforced main pillar material 4 Upper belly material (belly material, stress material)
4a Bottom node material (abdomen, stress material)
5 Internode horizontal material 5a Horizontal auxiliary material 51 New internode horizontal material (reinforcement stress material)
6 Diagonal auxiliary material (auxiliary material)
61 New diagonal auxiliary material 7 Joint 8 Bolt / Nut 8a Retention bolt 8b Additional bolt 9 Mounting plate (existing)
10 Stress transmission plate (reinforcement plate)
11 Welding downward part 12 Welding lateral part 13 Welding upward part 16 Buckling stiffener (horizontal auxiliary material)
17 Buckling stiffener (oblique auxiliary material)

Claims (5)

The reinforcement target part of the steel tower is a reinforcement method for a steel tower having a joint portion in which a bellows, a horizontal material, and an auxiliary material are bolted to a main pillar material constituting the steel tower,
A first step of welding and joining the main pillar material, the abdomen and the horizontal material in the joint;
A second step of removing the bolts joining the welded main pillar material, the belly material and the horizontal material ;
A third step of attaching a stress transmission plate for transmitting stress between the main column material, the abdomen and the horizontal material to the main column material in the joint;
A fourth step of joining a new horizontal member as a reinforcing member of the horizontal member to be reinforced to the stress transmission plate by bolting;
Steel tower reinforcement method including In the portion to be reinforced, when the main pillar material, the abdomen and the horizontal material are bolted together in a form sandwiching an existing attachment plate, in the first step, the attachment plate is connected to the main pillar material. The steel tower reinforcement construction method according to claim 1, wherein the main pillar material, the abdomen and the horizontal material are welded and joined by welding to the abdomen and the horizontal material , respectively . After the third step or the fourth step, a step of providing a reinforcing main column material to be added to the main column material of the portion to be reinforced, and a step of providing a new abdominal material to be added to the belly material of the portion to be reinforced The steel tower according to claim 1, wherein at least one of the step of providing a new auxiliary material to be attached to the stress transmission plate is performed on the auxiliary material of the portion to be reinforced. Reinforcement method. When the main pillar material is an angle material , in the step of providing the reinforcing main pillar material performed after the fourth step, the reinforcing main pillar material is overlapped and reinforced on the inner surface or the outer surface side of the main pillar material to be reinforced. The steel tower reinforcement construction method of Claim 3 provided with a form. In the reinforcing target portion, if another member is bonded to the inner or outer surface side of the main pillar reinforcement subject, so that it can bond the reinforcing main column member to the inner surface or outer surface of the main pillar reinforcement object The steel tower reinforcing method according to claim 3 or 4 , further comprising a cutting step of cutting a tip portion of the other member.

Images