JP6901983B2 - Steel rod stopper and steel rod stopper mounting structure - Google Patents

Description

The present disclosure relates to a steel rod stopper and a steel rod stopper mounting structure.

Conventionally, reinforced concrete structures have been widely used as structures such as viaducts for railways and roads. In such structures, steel rod stoppers, steel angle stoppers or damper type stoppers are used to connect the rigid frame viaduct or pier which is the substructure and the bridge girder which is the superstructure. The functions required of the stopper are to limit the movement of the girder against the horizontal force caused by an earthquake or the like, and to prevent the bridge collapse of the bridge girder. As the steel rod stopper, a steel rod stopper made of a round steel rod is used with a girder having a girder length of about 15 [m] or less (see, for example, Patent Document 1).

FIG. 1 is a perspective view showing an example in which a conventional steel rod stopper is applied to a connecting portion between a substructure and a superstructure, and FIG. 2 is a cross section of a connecting portion between the substructure and the superstructure to which the conventional steel rod stopper is applied. It is a figure. In FIG. 2, (a) is a vertical cross-sectional view of the entire connecting portion, and (b) is a cross-sectional view of the steel rod stopper.

In FIG. 1, reference numeral 21 denotes a viaduct girder used for a railway, which is a reinforced concrete structure or a prestressed concrete structure, on which a railway track, that is, a track 25 is laid. Reference numeral 11 denotes a pier of the viaduct, which has a reinforced concrete structure, supports the girder 21, and transmits a vertical load to the foundation or the ground. Specifically, the shoe seat 13 and the bearing body 14 are installed on the girder seat 12 above the pier 11, and the girder 21 is placed on the girder seat 12. In FIG. 1, for convenience of explanation, the figure of the digit continuous with the digit 21 is omitted.

Further, a steel rod stopper 31 made of a round steel rod 37 having a uniform diameter is embedded in the girder seat 12 and the girder end 22 in order to limit the horizontal movement of the girder 21 caused by a horizontal force due to an earthquake or the like. .. Specifically, as shown in FIG. 2, the lower end of the steel rod stopper 31 and the lower embedded portion 32B in the vicinity thereof are embedded in the girder seat 12, and at the upper end of the steel rod stopper 31 and its vicinity. A certain upper embedded portion 32A is housed and embedded in a sheath pipe 23 made of a steel pipe inserted into the girder end 22 so as to open to the lower surface 22a of the girder end. Further, the girder seat 12 and the girder end 22 surround the lower embedded portion 32B of the steel rod stopper 31 embedded in the girder seat 12 and the circumference of the sheath pipe 23 inserted into the girder end 22. A spiral reinforcing bar 26 is embedded in the pipe. When the upper embedded portion 32A and the lower embedded portion 32B are described in an integrated manner, they will be described as the embedded portion 32.

Then, as shown in FIG. 2, a play space 33 is provided between the girder seat upper surface 12a and the girder end lower surface 22a. As shown in FIG. 1, a plurality of the steel rod stoppers 31 are installed so as to be arranged in the width direction of the girder 21 (three in the example shown in FIG. 1).

Since the upper and lower sides of the steel rod stopper 31 are embedded in the girder seat 12 and the girder end 22, the horizontal movement of the girder 21 with respect to the pier 11 is appropriately restricted. When the inertial force G acts on the girder 21 as in the case of an earthquake, the steel rod stopper 31 receives the inertial force G as shown in FIG.

Japanese Unexamined Patent Publication No. 2010-242443

However, in the above-mentioned conventional technique, when a large inertial force G is received as in the case of an earthquake, the girder seat 12 as a substructure in which the lower embedded portion 32B of the steel rod stopper 31 is embedded, or the steel rod stopper The girder end 22 as a superstructure in which the upper embedded portion 32A of 31 is embedded may be damaged.

FIG. 3 is a photograph showing the damage to the superstructure in which the conventional steel rod stopper is embedded due to the earthquake, and FIG. 4 is a photograph showing the damage to the substructure in which the conventional steel rod stopper is embedded due to the earthquake. is there.

Damage to superstructures and substructures in railways and road viaducts, which are transportation networks, interrupts medical care, relief supplies, dispatch of rescue units, etc., and threatens human life, so it is necessary to recover immediately. However, as shown in FIGS. 3 and 4, when the girder end 22 or the girder seat 12 is damaged, inspection using an aerial work platform is required, and time and labor are required for restoration. Further, the damage occurs not only on the front surface 12b side of the girder seat 12, but also on the back surface 12c side (girder space) of the girder seat 12 as shown in FIG. 4, but the back surface 12c is an invisible part. Moreover, since the work space for performing the restoration work is narrow, not only the restoration takes a long time, but also the restoration work itself may become difficult.

Here, by solving the problems of the conventional technique and making the diameter of at least a part of the embedded portion of the steel rod stopper larger than the diameter of the clearance portion, the damage is concentrated on the clearance portion of the steel rod stopper. , Steel rod stopper and steel rod stopper that can suppress damage to the concrete of the structure in which the embedded part of the steel rod stopper is embedded, and can easily and quickly perform the restoration work of the structure. It is intended to provide a mounting structure.

Therefore, the steel rod stopper is a steel rod stopper made of a round steel rod in which at least the lower end is embedded in the substructure and at least the upper end is embedded in the superstructure placed on the substructure. A gap portion exposed in the gap between the substructure and the superstructure and an embedded portion embedded in the substructure and the superstructure are provided, and the diameter of at least a part of the embedded portion is the gap portion. much larger than the diameter, the diameter of the Joint Gap near portion which is a vicinity of the Joint Gap portion of the embedded portion is larger than the diameter of the Joint Gap portion, the diameter of the distal portion is a portion far from the Joint Gap portion of the buried portion It has smaller than the diameter of the Joint Gap vicinity.

In other steel rod stoppers, tapered portions are further formed at both ends of the clearance portion.

In still other steel rod stoppers, the cross-sectional rigidity of at least a part of the embedded portion is larger than the cross-sectional rigidity of the gap portion.

In the steel rod stopper mounting structure, at least the lower end is embedded in the substructure, the superstructure mounted on the substructure, and the substructure, and at least the upper end is embedded in the superstructure. A steel rod stopper made of a rod is provided, and the steel rod stopper includes a gap portion exposed in a gap between the substructure and the superstructure, and an embedded portion embedded in the substructure and the superstructure. , at least a portion of the diameter of該埋write section much larger than the diameter of the Joint Gap portion, larger than the diameter of the diameter the Joint Gap portion of the Joint Gap near portion which is a vicinity of the Joint Gap portion in the embedded portion, the diameter of distal portion is the portion far from the Joint Gap portion of the embedded portion had smaller than the diameter of the Joint Gap vicinity.

According to the present disclosure, the diameter of at least a part of the embedded portion of the steel rod stopper is made larger than the diameter of the clearance portion. As a result, the damage can be concentrated on the loose portion of the steel rod stopper, and the damage to the concrete of the structure in which the embedded portion of the steel rod stopper is embedded can be suppressed, and the restoration work of the structure can be easily performed. , Can be done quickly.

It is a perspective view which shows the example which applied the conventional steel bar stopper to the connecting part between a substructure and a superstructure. It is sectional drawing of the connection part of the substructure and superstructure to which the conventional steel rod stopper is applied. It is a photograph showing the damage caused by the earthquake to the superstructure in which the conventional steel rod stopper is embedded. It is a photograph showing the damage caused by the earthquake to the substructure in which the conventional steel rod stopper is embedded. It is a figure which shows the relationship between the horizontal load and the horizontal displacement obtained by the loading test of the structure in 1st Embodiment. It is a photograph which shows the damage received by the loading test of the structure in 1st Embodiment. It is a figure which shows the distribution of the bearing pressure stress obtained by the reproduction analysis of the structure in 1st Embodiment. It is a figure which shows the steel rod stopper in 1st Embodiment. It is a figure which shows the steel rod stopper in the 2nd Embodiment.

Hereinafter, embodiments will be described in detail with reference to the drawings.

FIG. 5 is a diagram showing the relationship between the horizontal load and the horizontal displacement obtained by the load test of the structure in the first embodiment, and FIG. 6 is a diagram showing the damage received by the load test of the structure in the first embodiment. FIG. 7 is a diagram showing the distribution of bearing stress obtained by the reproduction analysis of the structure in the first embodiment. In FIG. 6, (a) is a photograph showing the damage received by the first loading test, and (b) is a photograph showing the damage received by the second loading test.

In the present embodiment, the explanations in the sections of "Background Technology" and "Problems to be Solved by the Invention" are used to refer to the structure, operation and effect of each part in the connecting portion between the substructure and the superstructure. With respect to the same as those described in the sections of "Background Art" and "Problems to be Solved by the Invention", the same reference numerals as those shown in FIGS. 1 and 2 will be assigned, and the description thereof will be omitted as appropriate.

Further, in the present embodiment, the directions of upper, lower, left, right, front, rear, etc., which are used to explain the configuration and operation of each part of the connecting portion between the substructure and the superstructure and other members, are used. The expressions shown are relative rather than absolute, and are appropriate when each part of the connection between the substructure and the superstructure and other members are in the posture shown in the figure, but the posture is If it changes, it should be changed and interpreted according to the change in posture.

As explained in the section "Problems to be solved by the invention", when structures such as superstructures and substructures in railway viaducts are damaged, the damaged parts are the girder end 22 and the girder seat 12. If so, not only will it take a long time to recover, but the recovery work itself may become difficult. Therefore, a loading test is conducted to clarify what kind of damage the structure will be damaged in the event of a disaster. By such a loading test, the relationship between the residual yield strength of the concrete of the steel rod stopper 31 and the concrete of the girder seat 12 which is the substructure in which the lower embedded portion 32B of the steel rod stopper 31 is embedded and the damage is clarified. It's getting better.

FIG. 5 shows a curve showing the relationship between the horizontal load and the horizontal displacement obtained as a result of the first and second (No. 1 and No. 2) loading tests. It is also shown that the steel rod stopper 31 yielded and that the concrete of the girder seat 12 as shown in FIG. 6 was peeled off.

Further, by performing an analysis based on the result of the loading test as shown in FIG. 5, as shown in FIG. 7, the girder seat 12 in which the lower embedded portion 32B of the steel rod stopper 31 is embedded is embedded. The distribution of bearing pressure in concrete can be reproduced. From the results shown in FIG. 7, it can be seen that the bearing pressure is concentrated in the vicinity of the girder upper surface 12a.

The concrete around the embedded portion 32 of the steel rod stopper 31 is difficult to suppress damage by the current design method and structural details. Therefore, here, the damage of the concrete around the embedded portion 32 is controlled by changing the specifications of the steel rod stopper 31 from the damage mechanism.

FIG. 8 is a diagram showing a steel rod stopper according to the first embodiment. In the figure, (a) is a side view, and (b) is a cross-sectional view taken along the line AA in (a).

As shown in FIG. 8A, the steel rod stopper 31 in the present embodiment is made of a round steel rod 37, and has an upper embedded portion 32A embedded in the girder end 22 as a superstructure and a lower portion. The diameter of the lower embedded portion 32B embedded in the girder seat 12 as a work is set to be larger than the diameter of the clearance portion 33 exposed in the gap 24 between the girder seat upper surface 12a and the girder end lower surface 22a. Therefore, the cross-sectional rigidity of the upper embedded portion 32A and the lower embedded portion 32B is larger than the cross-sectional rigidity of the clearance portion 33. The upper embedded portion 32A and the lower embedded portion 32B are set to have the same diameter. That is, the embedded portion 32 is set to have a larger diameter than the gap portion 33. Then, in FIG. 8B, the circle indicated by the solid line indicates the outer circumference of the large-diameter embedded portion 32, and the circle indicated by the dotted line indicates the outer circumference of the small-diameter free space portion 33.

In the example shown in FIG. 8, the diameter of the large-diameter embedded portion 32 is about 120 [mm], the diameter of the small-diameter clearance portion 33 is about 100 [mm], and the length of the embedded portion 32 is. It is about 600 [mm], and the length of the small diameter clearance portion 33 is about 100 [mm], but the diameter and length of each portion can be changed as appropriate. It is desirable that the diameter of the embedded portion 32 is set so that the cross-sectional rigidity thereof increases the cross-sectional rigidity of the gap portion 33. Further, it is desirable that tapered portions 33a are formed at both ends of the gap portion 33 in order to avoid a sudden cross-sectional change and to make the cross-sectional change gentle.

As shown in FIG. 8, the clearance portion 33 exposed in the gap 24 between the girder end upper surface 12a and the girder end lower surface 22a has a small diameter to make the cross-sectional rigidity relatively small, and is embedded in the girder end 22 and the girder seat 12. By making the embedded portion 32 a large diameter and relatively increasing the cross-sectional rigidity, damage is concentrated on the loose portion 33 of the steel rod stopper 31 when a large inertial force G is received as in an earthquake, and the girder end. Damage to the concrete around the embedded portion 32 in the 22 and the girder seat 12 can be suppressed. The workability when embedding the embedded portion 32 in the girder end 22 and the girder seat 12 is the same as that of the conventional steel rod stopper 31 having a uniform outer diameter.

As described above, in the present embodiment, at least the lower end of the steel rod stopper 31 is embedded in the girder seat 12 as the substructure, and at least in the girder end 22 as the superstructure mounted on the girder seat 12. It consists of a round steel rod 37 with an embedded upper end. The steel rod stopper 31 includes a clearance portion 33 exposed in the gap 24 between the girder seat 12 and the girder end 22, and an embedded portion 32 embedded in the girder seat 12 and the girder end 22. The diameter of at least a part of the portion 32 is larger than the diameter of the clearance portion 33.

Further, in the steel rod stopper mounting structure of the present embodiment, at least the lower end is embedded in the girder seat 12 as the substructure, the girder end 22 as the superstructure mounted on the girder seat 12, and the girder seat 12. A steel rod stopper 31 made of a round steel rod 37 which is embedded and whose upper end is embedded at least in the girder end 22 is provided, and the steel rod stopper 31 is exposed to a gap 24 between the girder seat 12 and the girder end 22. The clearance portion 33 and the embedded portion 32 embedded in the girder seat 12 and the girder end 22 are included, and the diameter of at least a part of the embedded portion 32 is larger than the diameter of the clearance portion 33.

As a result, the damage can be concentrated on the loose portion 33 of the steel rod stopper 31, and the damage to the concrete of the structure in which the embedded portion 32 of the steel rod stopper 31 is embedded can be suppressed, and the restoration work of the structure can be performed. It can be done easily and quickly.

Further, tapered portions 33a are formed at both ends of the gap portion 33. Therefore, the occurrence of stress concentration can be suppressed, and the damage to the concrete of the structure can be suppressed more effectively.

Further, the cross-sectional rigidity of at least a part of the embedded portion 32 is made sufficiently larger than the cross-sectional rigidity of the clearance portion 33. By reducing the cross-sectional rigidity of the play space 33 in this way, damage to the concrete of the structure can be efficiently suppressed.

Next, the second embodiment will be described. For those having the same structure as that of the first embodiment, the description thereof will be omitted by assigning the same reference numerals. Further, the description of the same operation and the same effect as that of the first embodiment will be omitted.

FIG. 9 is a diagram showing a steel rod stopper according to the second embodiment. In the figure, (a) is a side view, and (b) is a cross-sectional view taken along the line BB in (a).

As can be seen from the results shown in FIG. 7, when a large inertial force G is applied, the bearing pressure of the concrete is concentrated in the portion close to the void 24. Therefore, as shown in FIG. 9, the steel rod stopper 31 in the present embodiment has a large diameter and a large cross-sectional rigidity only in the vicinity of the clearance portion 33 in the embedded portion 32.

More specifically, the gap near portion 32Aa in the upper embedded portion 32A and the gap near portion 32Ba in the lower embedded portion 32B have a larger diameter than the gap portion 33, and the far portion 32Ab and the lower embedded portion in the upper embedded portion 32A. The far portion 32Bb in the portion 32B has the same diameter as the play portion 33. When the gap near portion 32Aa in the upper embedded portion 32A and the gap near portion 32Ba in the lower embedded portion 32B are described in an integrated manner, they are described as the gap near portion 32a, and the distant portion 32Ab and the far portion 32Ab in the upper embedded portion 32A. When the distant portion 32Bb in the lower embedded portion 32B is described in an integrated manner, it will be described as the distant portion 32b. In the example shown in FIG. 9, the diameter of the large-diameter clearance portion 32a is about 120 [mm], the diameter of the small-diameter clearance portion 33 and the distant portion 32b is about 100 [mm], and the embedded portion 32. The length of the gap portion 33 is about 600 [mm], the length of the small-diameter clearance portion 33 is about 100 [mm], and the length of the gap vicinity portion 32a is about 300 [mm]. The length can be changed as appropriate.

As described above, in the present embodiment, the diameter of the gap portion 32a, which is a portion near the gap portion 33 in the embedded portion 32, is larger than the diameter of the gap portion 33. Further, the diameter of the distant portion 32b, which is a portion of the embedded portion 32 far from the clearance portion 33, is smaller than the diameter of the gap vicinity portion 32a.

As a result, the cross-sectional rigidity of the portion where the bearing pressure of the concrete of the structure is concentrated can be increased, and the damage of the concrete of the structure can be efficiently suppressed.

Since the effects of other points are the same as those of the first embodiment, the description thereof will be omitted.

The disclosure herein also describes features relating to preferred and exemplary embodiments. Various other embodiments, modifications and modifications within the scope and purpose of the claims attached herein can be naturally conceived by those skilled in the art by reviewing the disclosure of the present specification. is there.

The present disclosure can be applied to steel rod stoppers and steel rod stopper mounting structures.

12 Girder seat 22 Girder end 24 Void 31 Steel rod stopper 32A Upper embedded part 32Aa, 32Ba Free space near part 32Ab, 32Bb Far part 32B Lower embedded part 33 Free space 33a Tapered part 37 Round steel rod

Claims (4)

A steel rod stopper made of a round steel rod having at least the lower end embedded in the substructure and at least the upper end embedded in the superstructure placed on the substructure.
The free space exposed in the gap between the substructure and the superstructure,
It is provided with the substructure and an embedded portion embedded in the superstructure.
At least a portion of the diameter of該埋write section much larger than the diameter of the Joint Gap portion,
The diameter of the gap near portion, which is a portion near the gap portion in the embedded portion, is larger than the diameter of the gap portion, and the diameter of the distant portion, which is a portion far from the gap portion in the embedded portion, is the diameter of the gap vicinity portion. steel rod stopper characterized by smaller than Ikoto. The steel rod stopper according to claim 1, wherein tapered portions are formed at both ends of the clearance portion. The steel rod stopper according to claim 1, wherein the cross-sectional rigidity of at least a part of the embedded portion is larger than the cross-sectional rigidity of the gap portion. Substructure and
The superstructure placed on the substructure and
A steel rod stopper made of a round steel rod having at least the lower end embedded in the substructure and at least the upper end embedded in the superstructure is provided.
The steel rod stopper includes a gap portion exposed in a gap between the substructure and the superstructure, and an embedded portion embedded in the substructure and the superstructure, and at least a part of the embedded portion. diameter much larger than the diameter of the Joint Gap portion,
The diameter of the gap near portion, which is a portion near the gap portion in the embedded portion, is larger than the diameter of the gap portion, and the diameter of the distant portion, which is a portion far from the gap portion in the embedded portion, is the diameter of the gap vicinity portion. steel rod stopper mounting structures characterized by smaller than Ikoto.

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