JP2000230270A - Connecting structure and connecting method for concrete member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connecting structure and a connecting method for a concrete member capable of introducing tensile force to PC steel bars in a small work space. SOLUTION: A first PC steel bar 21 is fitted to a first concrete member 11, and a plurality of second PC steel bars 22 are fitted to a second concrete member 12. The first PC bar 21 and the second PC bars 22 introduced with tensile force on one of them are connected together via a connecting beam 4 so that their axes become parallel. The connecting beam 4 is pushed upward by a hydraulic apparatus arranged between the connecting beam 4 and the second concrete member 12 to pull the second steel bars 22. The first PC steel bar 21 and the connecting beam 4 are re-connected to introduce tensile force to the PC steel bars 21, 22 respectively. The thin hydraulic apparatus can be utilized, thus the work space can be made smaller than before.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure and a method for connecting a plurality of concrete members using a PC steel bar.

[0002]

2. Description of the Related Art Conventionally, in order to construct a concrete structure such as a culvert (a sewer for sewage), PC steel bars are provided inside a plurality of concrete members, and ends of the PC steel bars are connected. There is known a device in which a tension (prestress force) is introduced. In a conventional example of this structure, first and second PC steel bars are provided in advance inside first and second concrete members, respectively, and these first and second concrete members are arranged side by side. One end of the first and second PC steel bars facing each other are connected by a coupler, and the other end of the first PC steel bar is fixed by a nut. PC from end
Tension is introduced into the entire steel bar, and then the other end of the second PC steel bar is tightened with a nut.

Conventionally, a center hole type hydraulic jack has been used to introduce tension into a PC steel bar. This hydraulic jack has a configuration in which a main body having a large center hole through which one PC steel rod can be inserted is formed at the center, and a tension mechanism that holds and pulls an end peripheral surface of the PC steel rod. .

In the conventional example described above, a nut is attached to the other end of the first PC steel rod, and tension is introduced from the other end of the second PC steel rod using a center-hole type hydraulic jack. Therefore, a large working space is required on the other end side of the first and second PC steel bars. Therefore, the other ends of these PC steel bars are exposed so as to protrude from the end surfaces of the concrete members. When another concrete member is provided in contact with the end face of the concrete member, the first and second PCs of the concrete member are provided.
A large dent is formed near the other end of the steel bar to secure a working space.

[0005]

In the above-mentioned conventional example, 1
In order to introduce tension by pulling a PC steel bar (second PC steel bar), the means for introducing the tension is P
It must be a center hole type hydraulic jack that can securely hold the peripheral surface of the end of the C steel rod. In this hydraulic jack, a center hole for positioning the PC steel rod at the center is formed at the center of the main body, and the main body has a strength that can withstand when pulling the peripheral surface of the end of the PC steel rod by the tension mechanism. Inevitably results in a large structure. for that reason,
A large work space is required on the other end side of the first and second PC steel bars, and if this work space cannot be secured, there is a problem that the work of introducing tension becomes difficult.

It is an object of the present invention to provide a small work space with a connection, rather than from the end of a connected PC steel bar.
It is an object of the present invention to provide a concrete member connecting structure and a connecting method capable of introducing a tension to a C steel rod.

[0007]

Therefore, according to the present invention, at least one of the first and second PC steel bars provided on the first and second concrete members, respectively, is provided as a plurality, and Introduce tension on one side in advance,
The first and second PC steel bars are connected to each other with their connecting ends connected by connecting beams, and tension is applied to the PC steel bars through the connecting beams to achieve the above object. It is.

[0008] Specifically, the concrete member connecting structure of the present invention comprises a first concrete member and a first PC.
Attach a steel rod and attach a second P
A first C-bar and a second P-bar are attached.
A structure in which ends of a C steel bar are connected to each other to connect a plurality of concrete members, wherein the first PC steel bar and the second P steel bar, each of which is pretensioned in one of the two members,
A first PC steel bar and a second P steel bar are connected to each other via a connecting beam so that their axes are parallel to each other.
It is characterized in that at least one of the C steel bars is composed of a plurality of bars.

Further, according to the method for connecting concrete members of the present invention, a first PC steel rod is attached to a first concrete member, and the axes of the first PC steel rods are parallel to each other. A second PC steel bar is attached to a second concrete member, and at least one of the first PC steel bar and the second PC steel bar is composed of a plurality of bars. A tension is previously introduced into one of the second PC steel bars, and the first PC steel bar and the second P
The ends of the C steel bar are connected to each other via a connecting beam, and then one of the first PC steel bar and the second PC steel bar is connected to the first PC steel bar via the connecting beam. It is characterized in that it is pulled toward the other of the bar and the second PC steel bar, and the other of the first PC steel bar and the second PC steel bar is connected to the connection beam again.

According to the present invention, the first PC steel rod and the second P
One side of the C rod, for example the first PC rod, must be pretensioned. According to the present invention, for example, a predetermined pressure device, for example, a single-acting cylinder type hydraulic jack is arranged between the connecting beam and the second concrete member, and the connecting beam is operated by operating the hydraulic jack. The second PC steel rod is given a tension equal to or greater than the tension previously applied to the first PC steel rod. As a result, if the space between the connecting beam and the end of the first PC steel bar becomes loose, the loosened portion is reconnected.

Then, a tension equal to or higher than the tension introduced to the first PC steel rod is applied to the first PC steel rod and the second PC steel rod, respectively.
As a result, the first and second concrete members can be connected with a large tension. When the connection operation is completed, the first PC steel bar and the second PC steel bar can be made into a mechanically continuous body by unloading the hydraulic jack. Therefore, when tension is introduced into the PC steel bar, the end of the PC steel bar is not directly held by the hydraulic device, so there is no need to use a hydraulic device having a large structure, and the working space is smaller than before. Small is enough.

Further, in the connection structure of the present invention, the first
A plurality of PC steel bars and the second PC steel bar are provided respectively, and the first PC steel bar and the second PC steel bar are equally spaced apart from each other by a predetermined angle about the virtual axis. The arrangement | positioning may be sufficient. In this configuration, since both the first and second PC steel bars are plural, even if one PC steel bar itself is thin, large tension can be introduced as the whole PC steel bar. it can. Therefore, the first and second
The connection strength of the concrete members can be increased. In addition, since the first PC steel bar and the second PC steel bar are equally spaced apart from each other by a predetermined angle about the virtual axis, the first concrete member and the second concrete member are connected to each other. A stable connection state can be ensured by equalizing the connection force.

Further, the first PC steel bar and the connection beam are connected via a first nut member, and the second PC steel bar is connected to the second PC beam.
The steel bar and the connection beam may be connected via a second nut member. In this configuration, the first and second PCs
The connection between the connection beam and the PC steel bar is performed by screwing a nut member into a bolt formed at the end of the steel bar. A tension equal to or greater than the tension previously applied to the first PC steel bar is applied to the second PC steel bar via the connection beam, and a nut provided on the connection beam and the first PC steel bar. The gap created between the members is set to zero by screwing the nut member. Therefore, in the case of a slight tension (prestressing force), the nut member at the end of the second PC steel rod is screwed with a spanner or the like without using a hydraulic jack to apply a tension to the second PC steel rod. It is also possible to control the tension by confirming that the nut member used to introduce and preliminarily tension the first PC steel rod rotates freely.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the overall configuration of one embodiment, and FIG. 2 is a cross-sectional view taken along line II-II of FIG. In these figures, the present embodiment has a structure in which a first concrete part 11 and a second concrete member 12 that constitute a split box culvert are connected.

The first concrete member 11 constitutes an upper portion of the box culvert, and has a ceiling surface portion 1.
This is a structure in which a vertical portion 11B is formed vertically from the end of 1A. A rectangular parallelepiped connection work space 11C is formed below the vertical portion 11B. The second concrete member 12 constitutes a lower portion of the box culvert, and extends vertically from an end of the bottom plate surface portion 12A.
B is a structure formed to be steep. The upper end surface of the vertical portion 12B is the vertical portion 11B of the first concrete member 11.
Is joined to the lower end surface.

The vertical portion 1 of the first concrete member 11
1B, one first PC steel rod 21 is attached to the first PC steel rod 21 extending vertically and a nut 31 is screwed into a bolt part 21A formed at the upper end of the first PC steel rod 21.
A nut 31 is screwed at a position separated by a predetermined distance from the lower end of the bolt 21B formed at the lower end. An anchor plate 32 for supporting pressure is provided at the upper end of the first PC steel bar 21.
Is provided adjacent to the nut 31. A nut 31 screwed to the lower end of the first PC steel bar 21 is provided to be exposed in the connection work space 11C.
A support anchor plate 32 is interposed between 1 and the upper end surface of the connection work space 11C.

The vertical portion 1 of the second concrete member 12
2B, two second PC steel rods 22 are attached, and these second PC steel rods 22 extend vertically so that their respective axes are parallel to the axis of the first PC steel rod 21. It is arranged. In these second PC steel bars 22, nuts 31 are screwed to lower ends of bolt portions 22B formed at lower ends thereof, and supporting anchor plates 32 are adjacent to these nuts 31, respectively. Is provided.

In the connection work space 11C, the upper end of the two second PC steel bars 22 and the lower end of the first PC steel bar 21 are connected to each other via the connection beam 4.
The connection structure between the first PC steel bar 21 and the second PC steel bar 22 is shown in FIGS. 3 and 4 in an enlarged manner. FIG.
FIG. 4 is a sectional view showing details of the connection structure, and FIG.

In these figures, the connecting beam 4 is formed of a substantially rectangular parallelepiped block, and a stepped cylindrical nut storage space 4A is formed at the center thereof along the vertical direction. Steel rod insertion holes 4B through which the second PC steel rods 22 are inserted are formed vertically.
A gap is formed between the steel rod insertion hole 4B and the second PC steel rod 22 to absorb a mounting error of the connecting beam 4.

In the nut storage space 4A, a first nut member 51 is provided so as to be movable in the axial direction of the first PC steel bar 21 and rotatable in the circumferential direction. The first nut member 51 is provided at the lower end bolt portion 21 of the first PC steel bar 21.
B, and a nut portion 51A screwed with B.
And a holding portion 51B integrally formed. The holding portion 51B is provided with a nut storage space 4 for the connecting beam 4.
The lower end is formed in a stepped cylindrical shape with a large diameter in order to prevent it from falling out of A. An insertion hole 51C through which the lower end portion of the first PC steel rod 21 screwed to the nut portion 51A is inserted is formed in the axis of the holding portion 51B so as to extend vertically. Upper end bolt portion 22A of second PC steel bar 22
Is screwed with a second nut member 52,
A washer 53 is interposed between the nut member 52 and the upper surface of the connecting beam 4.

Next, a method of connecting concrete members according to the present embodiment will be described. First, in a factory, the first concrete member 11 is manufactured, and the first PC steel bar 21 is attached to the first concrete member 11.
Further, the second concrete member 12 is manufactured, and the second concrete member 12 is provided with a second PC.
Attach the steel bar 22.

The first and second concrete members 11,
12 to the construction site. At the construction site, the second concrete member 12 is placed at a predetermined position using a heavy machine such as a crane, and then the second concrete member 12
The first concrete member 11 is placed on the above. Second
When the first concrete member 11 is installed on the concrete member 12 of the first embodiment, the lower end of the first PC steel bar 21 is connected to the connecting work space 11C formed in the first concrete member 11, The upper end of the second PC steel rod 22 of the book is exposed.

The first concrete member 12 is placed on the second concrete member 12.
Before the concrete member 11 is installed, the upper end portion of the second PC steel bar 22 is inserted into the insertion hole 4B of the connecting beam 4, and the first nut member 5 is inserted into the nut storage space 4A of the connecting beam 4.
Insert 1 in advance. At the factory or construction site,
The tension Pi is introduced into the first steel bar 21 attached inside the first concrete member 11 by a normal method.

Thereafter, the first nut member 51 is screwed into the lower end of the first PC steel bar 21 to expose the nut portion 51A of the first nut member 51 upward from the upper end surface of the connecting beam 4. Then, the connecting beam 4 is positioned at a predetermined height from the upper end surface of the second concrete member 12. Further, a hydraulic device 60 is installed in a space between the connecting beam 4 and the upper end surface of the second concrete member 12. The structure of the hydraulic device 60 is shown in FIG. In FIG.
In the hydraulic device 60, a thick disk-shaped piston 62 is provided to be able to advance and retreat in a short-sized cylindrical casing 61 having a bottom, and a coupler 63 is provided between the piston 62 and the bottom of the casing 61.
Is a single-acting cylinder-type hydraulic jack to which hydraulic oil is supplied via a hydraulic cylinder.

Further, the second nut member 52 is fastened to the upper end bolt portion 22A of the second PC steel bar 22 without play. In fastening the second nut member 52 to the upper end bolt portion 22A of the second PC steel rod 22, a washer 53 is interposed between the second nut member 52 and the upper surface of the connection beam 4. As a result, the first P
The C steel bar 21 and the second PC steel bar 22 are connected to each other. In this state, when hydraulic oil is supplied to the hydraulic device 60 sandwiched between the connecting beam 4 and the upper end surface of the second concrete member 12, the piston 62 moves forward to push the connecting beam 4 upward. The force for pushing up the connecting beam 4 is Pr larger than the tension Pi.

As a result, the connecting beam 4 moves upward, and the tension Pr is introduced into the two second PC steel bars 22 via the second nut member 52 and the washer 53. . Further, even if the connecting beam 4 moves upward, the first nut member 51 stops at a predetermined position, and the first nut member 51
There is play between the beam and the connecting beam 4. To eliminate this play, the nut portion 51A of the first nut member 51 is screwed using a tool such as a spanner.

It is determined whether the tension Pr greater than the tension Pi previously introduced into the first PC steel bar 21 has been introduced or not.
The determination is made based on whether the nut 31 screwed to the lower end of the C steel bar 21 is loose. The first PC steel rod 21 and the second
The hydraulic equipment 60 is removed when the tension is introduced into the PC steel bar 22 of each of the above.

Therefore, in the present embodiment, the first PC steel rod 21 is attached to the first concrete
Two second PC steel rods 22 on the concrete member 12
And a first PC steel rod 21 and a second PC steel rod 22
Are connected to each other via the connecting beam 4 so that their axes are parallel, and the connecting beam 4 and the second concrete member 12 are connected to each other.
The connecting beam 4 is pushed upward by the hydraulic device 60 disposed between the second PC steel bar 22 and the second PC steel bar 22 is pulled.
Since the first PC steel bar 21 and the connection beam 4 were reconnected to each other and tension was applied to the first PC steel bar 21 and the second PC steel bar 22, respectively, the first and second PC steel bars were connected. When introducing tension into the rods 21 and 22, a thin single-acting cylinder type hydraulic jack can be used instead of a large center hole type hydraulic jack that grips the peripheral surface of a steel rod. Therefore, the work space for connecting the first concrete member 11 and the second concrete member 12 can be reduced as compared with the conventional case.

In addition, the first PC steel rod 21 and the second PC
Before the ends of the steel bars 22 are connected to each other via the connecting beams 4, tension Pi is introduced into the first PC steel bar 21 in advance. Therefore, a force Pr equal to or higher than the tension Pi. By pulling the second PC steel bar 22 toward the first PC steel bar 21, the first PC steel bar 21 and the second PC steel bar 22 are respectively connected to the first PC steel bar. A tension equal to or greater than the introduced tension will be introduced. As a result, the first and second concrete members 11, 12 can be connected with a large tension.

In addition, the upper end of the first PC steel bar 21
Since they do not protrude from the upper end surface of the first concrete member 11 and the lower end of the second PC steel bar 22 does not protrude from the lower end surface of the second concrete member 12, Concrete members 11 and 12
Another concrete member can be connected to the upper end or the lower end.

Further, the first PC steel bar 21 and the connecting beam 4 are connected via a first nut member 51, and the second PC steel bar 22 and the connecting beam 4 are connected to a second nut member 52. If it is a slight tension (prestressing force), the second nut member 52 is screwed into the second PC steel bar 22 with a spanner or the like to apply a tension to the second PC steel bar 22. It is also possible to control the tension by confirming that the nut 31 used to introduce and pre-tension the first PC steel rod 21 rotates freely. Furthermore, the first P
A tension greater than the tension Pi previously introduced to the C steel rod 21
Whether or not Pr has been introduced can be determined based on whether or not the nut 31 screwed to the lower end of the first PC steel bar 21 is loose, so that the tension can be easily managed.

Further, the first nut member 51 has a nut portion 51A screwed with the lower end portion of the first PC steel bar 21.
And the holding portion 51B which is formed integrally with the nut portion 51A and is rotatable and axially movable, so that the nut portion 51A can be a normal nut. The structure of the first nut member 51 can be simplified.

Further, since the holding portion 51B is formed in a stepped cylindrical shape having a large diameter at the lower end portion, the nut portion 51A is formed.
Is screwed into the lower end of the first PC steel bar 21 when the first
Of the nut member 51 does not come off the connecting beam 4. Therefore, the connecting operation can be easily performed. further,
An insertion hole 5 through which the lower end of the first PC steel rod 21 screwed with the nut 51A is inserted into the axis of the holding portion 51B.
1C extends in the axial direction of the first PC steel rod 21 and is formed through the first PC steel rod 21. Therefore, even if the length of the first PC steel rod 21 protruding from the nut 31 is long, the first PC steel rod 21 has the first nut member 51. One PC steel bar 21 can be held.

The steel rod insertion hole 4 formed in the connecting beam 4
Since a gap having a predetermined size is formed between B and the second PC steel bar 22, an installation error of the connecting beam 4 can be absorbed by the gap. Furthermore, since the washer 53 is interposed between the second nut member 52 and the upper surface of the connection beam 4, even if a large tension is introduced to the second PC steel bar 22 by the hydraulic device 60, Connecting beam 4,
The power can be transmitted to the first nut member 51 and the first PC steel bar 21.

The present invention is not limited to the above-described embodiment, but includes modifications and improvements as long as the object of the present invention can be achieved. For example,
In the above embodiment, the first PC steel rod 21 is one and the second PC steel rod 22 is two. However, in the present invention, the first PC steel rod 21 is replaced by the second PC steel rod 22. May be constituted by the same number as that of the first embodiment.
And a second PC steel rod 22
You may comprise from a book. However, when a plurality of the first PC steel bars 21 and the second PC steel bars 22 are provided, respectively, the first PC steel bars 21 and the second PC steel bars 22 are provided.
Need to be arranged at equal intervals around the virtual axis.

For example, as shown in FIG.
The number of the steel bars 21 and the second PC steel bars 22 may be two. In this case, the axis of the substantially short cylindrical connecting beam 41 is a virtual axis, and the two second rods are centered on the virtual axis. The first PC steel bars 21 are arranged at equal intervals from each other, and the two second PC steel bars 22 are mutually centered about the virtual axis in a direction orthogonal to a straight line connecting the positions where the first PC steel bars 21 are arranged. They are arranged at equal intervals. In FIG. 6, the illustration of the second nut member 52 and the washer 53 is omitted.

In the connection structure shown in FIG. 6, the first PC
A plurality (two) of both the steel bar 21 and the second PC steel bar 22
Therefore, even if the single PC steel rods 21 and 22 are thin, large tension can be introduced to the entire PC steel rods 21 and 22. Therefore, the connection strength between the first and second concrete members 11 and 12 can be increased. Moreover, the first PC steel rod 21 and the second PC steel rod 22
Are uniformly spaced apart from each other by a predetermined angle about the virtual axis, so that the connecting force between the first concrete member 11 and the second concrete member 12 is made uniform to secure a stable connection state. be able to.

Further, in the present invention, when the first PC steel rod 21 is composed of one rod, the second PC steel rod 22 may be composed of a plurality of three or more rods. For example, FIG.
, The second PC steel bar 22 may be composed of four bars. In this case, the second PC steel rod 22 is connected to the first PC
In order to arrange the steel bars 21 at equal intervals around the arrangement position thereof, the second P
A steel rod insertion hole 4B through which the C steel rod 22 is inserted is formed. In FIG. 7, the second nut member 52 and the washer 5
The illustration of 3 is omitted.

Further, like the second nut member 52, the first nut member 51 may be formed of a normal nut. When the first nut member 51 is formed of a normal nut, a through hole is formed in the center of the connecting beam 4, and the lower end of the first PC steel rod 21 is inserted into the through hole to connect the connecting beam 4. 4
The lower end of the first PC steel bar 21 projecting from the lower end surface of the first PC steel bar is screwed with a nut.

The connection structure to which the present invention is applied can be applied not only to the connection between precast concrete columns and foundation concrete but also to the connection of a plurality of concrete members. Furthermore, the first and second concrete members 11, 1 arranged vertically.
2 and the first and second concrete members 11 and 12 arranged in the left and right or oblique directions.
The present invention can also be used for connecting Further, the PC steel rod of the present invention can be applied to an unbonded type, a sheath grout type, an after-bonded type, and the like.

[0041]

According to the present invention, the first PC member is attached to the first concrete member, and the second PC member is attached to the second concrete member. A first PC steel rod having at least one of a plurality of rods and tension applied to one of the rods and a second P steel rod.
C steel bars are connected to each other via connecting beams such that their axes are parallel to each other, and the first PC steel bar or the second PC steel bar is pulled through the connecting beams. By reconnecting the PC steel bar or the second PC steel bar and the connecting beam, each P
Since tension was introduced into the C steel bar, the first PC steel bar and the second
The PC steel rod is mechanically continuous, and the concrete member is securely connected. In introducing this tension, a thin single-acting cylinder type hydraulic jack can be used instead of a large center-hole type hydraulic jack that grips the peripheral surface of a steel rod, so the working space is smaller than before. Can be smaller.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing the overall configuration of an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view showing details of a connection structure of the embodiment.

FIG. 4 is a sectional view showing a state in which the connection structure is disassembled.

FIG. 5 is a sectional view of a hydraulic device used in the embodiment.

FIG. 6 is a perspective view showing a main part of a modified example of the present invention.

FIG. 7 is a perspective view showing a main part of another modified example of the present invention.

[Explanation of symbols]

 4, 41, 42 Connecting beam 11 First concrete member 11C Space for connecting work 12 Second concrete member 21 First PC steel bar 22 Second PC steel bar 51 First nut member 52 Second Nut member 60 Hydraulic equipment

Claims (4)

[Claims] A first PC steel rod is attached to a first concrete member, and a second PC steel rod is attached to a second concrete member.
Attach the steel rods, these first PC steel rod and second PC
A structure in which ends of steel bars are connected to each other to connect a plurality of concrete members, wherein the first PC steel bar and the second PC steel bar are pre-tensioned to one of them.
A first steel bar and a second steel bar are connected to each other via a connecting beam so that their axes are parallel to each other;
A connection structure for concrete members, wherein at least one of the steel bars is constituted by a plurality of steel bars. 2. The concrete member connecting structure according to claim 1, wherein said first PC steel bar and said second PC steel bar are connected to each other.
A plurality of steel bars are provided, and the first P
A connection structure for concrete members, wherein the C steel bar and the second PC steel bar are equally spaced apart from each other by a predetermined angle about an imaginary axis. 3. The concrete member connecting structure according to claim 1, wherein said first PC steel bar and said connecting beam are connected via a first nut member, and said second PC steel bar is connected to said second PC member. A connection structure for a concrete member, wherein the steel bar and the connection beam are connected via a second nut member. 4. A first PC steel rod is attached to a first concrete member, and the second PC steel rod is connected to a second concrete rod such that the axis of the first PC steel rod is parallel to the axis. The first PC steel bar and the second PC steel bar are attached to one another, and at least one of the first PC steel bar and the second PC steel bar is composed of a plurality of bars. With the force introduced, these first PC steel rods and the second
Of the first and second PC steel bars are connected to each other via a connecting beam, and then one of the first PC steel bar and the second PC steel bar is connected to the first PC steel bar via the connecting beam. Pulling toward the other of the steel bar and the second PC steel bar;
A method for connecting concrete members, characterized by reconnecting the other of the first PC steel bar and the second PC steel bar to the connection beam.