JPH0656034B2 - Construction method for stringed beams - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a tension beam in which tension is introduced by tensioning a chord member.

“Prior Art and Its Problems” One of the frame structures of the roof of a long span structure is a string beam structure, and FIG. 5 shows an example of a structure constructed using the string beam 1. This structure consists of beam 2 made of steel truss
Is straddled between the columns 3 and 3 and both ends thereof are supported on the upper ends of the columns 3 and 3, and the string (string material) 4 connected between the both ends of the beam 2 is tensioned to act on the beam 2. It controls the stress. Reference numeral 5 in the drawing denotes a bundle material that supports the central portion of the string.

In order to construct the stringed beam 1 as described above, the beam 2 in which the strings 4 have been assembled in advance and the strings 4 have been connected is used to form the pillars 3.
The string 4 is tensioned by tensioning the string 4 immediately after the completion of finishing work such as roofing work or the like, but the form of support of the beam 2 to the column 3 is It is necessary to use a roller bearing that allows the beam 2 to freely slide on the column 3 in the length direction (span direction) thereof. This is because the introduced tension is effectively applied to the beam 2 by freely displacing the beam 2 with respect to the column 3 when the tension is introduced.

In addition, after the tension is introduced, there are two ways of thinking, that is, the form of support for the column 3 of the beam 2 is the roller support as it is, and that the support is switched from the roller support to the pin support. The latter is often adopted. That is, in the former case, the thrust force to the lower structure can be applied only during an earthquake, and thus the burden on the lower structure can be reduced, but the disadvantage is that the amount of deformation increases. On the other hand, in the latter case, the lower structure only needs to bear the thrust force of the additional load, and therefore, when the own weight becomes the dominant load, the economical efficiency of the lower structure can be greatly increased. This is because it is advantageous.

Then, as described above, when the roller bearing at the time of introducing the tension is switched to the pin bearing at the time of introducing the tension, the specific form of the pin bearing is to fix the fulcrum portion of the beam 2 to the column by welding. , Is conventionally common.
Strictly speaking, the form of such a bearing is a rigid joint and cannot be said to be a pin bearing. However, the type of such a bearing that has been conventionally adopted is that which is a roller bearing. This is because it is difficult to switch to a complete pin bearing, and the moment generated in the form of such a bearing is generally negligible and can be regarded as a pin bearing.

However, when adopting the above-mentioned welding support form for a stringed beam with a particularly large span length,
Since it is not a perfect pin bearing, mechanical problems may arise, and it is therefore desirable to provide a means by which a clearer or perfect pin bearing may be adopted.

The present invention has been made in view of the above circumstances, and the form of support for the column of the beam in the stringed beam is changed to a roller support when tension is applied, and a complete pin support is easily and promptly changed after tension is applied. The purpose of the present invention is to provide a method for constructing a stringed beam that can be used.

"Means for Solving the Problem" The present invention is to tension a chord member connected to a beam main body with respect to a beam main body having column members with pin insertion holes formed at the lower ends at both ends. When straddling the stringed beam adapted to introduce tension by means of supporting the lower end of the pillar member to the upper end of the pillar by straddling between the pillars, first, a pin insertion hole that can match the pin insertion hole of the pillar member And a guide member that guides the displacement in the span direction of the beam body and restrains the displacement in the girder direction are temporarily fixed to the upper ends of the columns so as to be movable in the span direction, and then the beam body is The column member by supporting the lower end of the column member on the upper end of the column member, and then tensioning the chord member to introduce tension to the beam body, and the guide member to the displacement amount of the beam body. In the span direction It is characterized in that the pin insertion holes are moved to match each other, the pins are inserted into the pin insertion holes to rotatably connect the beam main body to the guide member, and then the guide member is fixed to the upper end of the column. I am trying.

[Operation] In the method of constructing the stringed beam of the present invention, the form of the support for the column of the beam main body is the roller support before the tension is introduced, and is switched to the pin support immediately after the tension is introduced.

That is, before the tension is introduced, only the lower end of the column member provided at the end of the beam main body is supported on the upper end of the column, and the beam main body is provided as a roller bearing that can be freely displaced in the span direction when the tension is introduced. Moreover, the guide member temporarily fixed to the upper end of the column guides the displacement of the beam body in the span direction and restrains the displacement in the girder direction.

Then, after the tension is introduced, the guide member is moved in the span direction according to the displacement amount of the beam main body so that the pin insertion holes are aligned with each other, and the pins are inserted to rotatably connect the guide member and the guide member. By fixing to the column, the beam main body is supported by the pin via the guide member.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

FIG. 1 is an enlarged view of the end portion of the stringed beam 1 shown in FIG. 5, in which reference numerals 6, 7, and 8 denote beams (beam bodies), respectively.
The upper chord material, the lower chord material, and the lattice material that compose 2 are 9
Is a fixing member to which the string (string material) 4 is fixed.
Further, 10 is a pillar member provided at the end of the beam 2, and the beam 2 is bridged between the pillars 3 and 3 when the lower end of the pillar member 10 is supported by the upper end of the pillar 3 by a pin. It is like this. In the illustrated example, cut tee steel is used as the upper chord member 6 and the lower chord member 7 constituting the beam 2, a steel pipe is used as the lattice member 8, and an H-shaped steel is used as the pillar member 10, respectively. Although H-section steel having a cross-sectional dimension larger than that of the above-mentioned pillar member 10 is adopted as the above, the cross-sectional shape of each member may be appropriate.

The details of the pin support for the pillar 3 of the pillar member 10 are described in the second section.
Shown in FIGS.

As shown in these figures, the lower end portion of the pillar member 10 has a shape curved in an arc shape, and a pin insertion hole 11 is formed therein.

On the other hand, a base plate 12 and ribs 13 and 13 for reinforcing the base plate 12 are attached to the upper ends of the columns 3, and a pair of guide members 14 and 14 sandwiching the lower ends of the column members 10 from both sides are provided on the upper surface of the base plate 12. It is welded and fixed. These guide members 14, 14 are made of steel plates in an angled shape, and the bottom plate thereof has elongated holes 15
Are formed, and the pillar member 1 is provided on the vertical plate.
The pin insertion holes 16 and 16 that match the pin insertion hole 11 formed at the lower end portion of 0 are formed. Further, bolt holes (not shown) are formed in the base plate 12 at positions corresponding to the elongated holes 15 formed in the bottom plates of the guide members 14, 14. The guide members 14 and 14 are for guiding the displacement of the beam 2 in the span direction when introducing tension and restraining the displacement in the column direction, which will be described in detail later.

Then, the lower end portion of the pillar member 10 is arranged between the guide members 14 and 14 fixed on the base plate 12,
The pin 17 is inserted through the pin insertion holes 16, 11, 16 so that the beam 2 is rotatably supported by the column 3 via the guide members 14, 14.

As is clear from the above description, the form of this bearing is a perfect pin bearing, and the vertical load and the horizontal load are transmitted to the column 3, but the moment is not transmitted. Therefore, as described above, the economical efficiency of the substructure can be sufficiently achieved by this pin bearing, and even if the span length is large, there is no possibility of causing mechanical problems and a clear bearing form. ing.

In the above case, the lower end of the column member 10 which is curved in an arc shape is in contact with the base plate 12 and is rollable on the surface thereof, whereby the self-weight of the beam 2 and the vertical reversal of the additional load. The force is directly transmitted to the column 3 without passing through the pin 17. Therefore, no shearing force is applied to the pin 17 due to the vertical load,
Therefore, its strength is sufficient to withstand the thrust force of the additional load.

The configuration of the tension beam 1 and the form of pin support for the pillar 3 in this embodiment have been described above. Next, the construction method will be described.

First, a sliding material (not shown) such as a Teflon sheet having a small frictional resistance is laid on the base plate 12 at the upper end of the pillar 3, and the guide members 14, 14 are temporarily fixed to the upper surface thereof. The temporary fixing is performed by inserting bolts (not shown) into the long holes 15 formed in the guide members 14, 14 and the bolt holes (not shown) formed in the base plate 12, respectively. A nut (not shown) to be screwed into the bolt is tightened only loosely, and the base members 14, 14 within the range of the elongated holes 15 ...
It is made movable in the X direction shown in FIGS.

Next, the beam 2 preassembled in a truss shape and having the string 4 attached thereto is lifted by a crane (not shown) and bridged between the columns 3 and 3. At that time, the pillar member 10
The lower end portion of the column 3 is disposed between the base members 14, 14 which are temporarily fixed as described above, and is supported on the upper end of the column 3.
As a result, the beam 2 is guided by the guide members 14, 14
However, the displacement in the column direction (Y direction shown in FIGS. 3 and 4) is restrained by the guide members 14, 14.

Then, the string 4 is tensioned to introduce the tension into the beam 2. The beam 2 is deformed as the tension is introduced, and the lower end of the column member 10 slides on the base plate 12 in the span direction and is displaced. At this time, since the sliding member is laid on the base plate 12, the lower end of the column member 10 slides smoothly, and at this time, as described above, the displacement of the beam 2 in the column direction is caused by the guide member 14, 14
Therefore, there is no possibility that the end portion of the beam 2 moves in the column direction and the lower end of the column member 10 comes off the base plate 12 and falls.

When a predetermined tension is applied to the beam 2, the guide members 14 and 14 are moved in the span direction according to the displacement amount of the column member 10 so that those pin insertion holes 16 and 16
And the pin insertion hole 11 of the column member 10 are accurately aligned with each other, and the pin 17 is inserted there to connect them. At this time, since the sliding member is sandwiched between the guide members 14 and 14 and the base plate 12, the base members 14 and 14 can be easily moved.

Finally, if the guide members 14 and 14 are welded and fixed to the base plate 12, the beam 2 becomes the guide member 1.
It will be pin-supported to the pillar 3 via 4, 14. Then, the bolts that temporarily fix the base members 14, 14,
Remove the nut as it is no longer needed.

According to the above method, since the form of support of the beam 2 with respect to the column 3 is a roller support capable of displacing the beam 2 in the span direction at the time of introducing tension, the introduced tension is applied to the beam 2. Of course, after the tension is introduced, the guide members 14 and 14 are moved to align the pin insertion holes 16, 11 and 16, and the pin 17 is inserted into them to guide Member 1
Only by welding and fixing 4, 14 to the pillar 3, it is possible to immediately switch from the roller bearing to the complete pin bearing.

Then, when the tension is introduced, the guide members 14, 14 are temporarily fixed to the column 3, and are moved in the span direction according to the displacement amount of the beam 2 after the tension is introduced. , 14 and base plate 1
Since the sliding member is sandwiched between the two, the guide members 14, 1
4 can be easily and accurately moved and positioned.

The present invention is not limited to the above-mentioned embodiment, but the shape (dimensions, etc.) of the beam (beam main body), the column member provided at the end thereof, the guide member, etc. may be appropriately changed according to the design conditions. Of course good things.

[Advantages of the Invention] As described in detail above, according to the method of constructing a stringed beam of the present invention, after the guide member is temporarily fixed to the upper end of the column, the beam main body is supported on the upper end of the column in a displaceable manner in the span direction. Since the guide member guides the displacement of the beam body while introducing the tension, when the tension is introduced, the tension is applied to the roller so that the tension can be sufficiently applied to the beam body. After the tension is introduced, the guide members are moved to match the pin insertion holes, and after inserting the pins into them, the guide member is fixed to the column, so it is possible to quickly switch from the roller bearing to the complete pin bearing. You can Therefore, the economical efficiency of the lower structure can be sufficiently achieved, and a clear pin bearing that does not cause mechanical problems even when the span length is large can be easily realized. Is very effective.

[Brief description of drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is an elevation view showing an end portion of a tension beam in this embodiment, and FIG. 2 is an enlarged view of a portion II of FIG. 3 is a front view thereof, and FIG. 4 is a view taken along the line IV-IV of FIG. FIG. 5 is an elevation view showing the overall schematic structure of the stringed beam. 1 ... Stranded beam, 2 ... Beam (beam main body), 3 ... Column, 4 ... String (string material), 10 ... Column member, 11 ... Pin insertion hole, 14 ... Guide member, 16 ... Pin insertion hole, 17 ... Pin.

Claims (1)

[Claims] 1. A tension is introduced by tensioning a chord member connected to the beam body with respect to a beam body having a column member having a pin insertion hole formed at a lower end portion at both ends. When straddling a strut string beam between columns to support the lower end of the column member at the upper end of the column, first, a pin insertion hole that can match the pin insertion hole of the column member is formed and A guide member for guiding the displacement of the main body in the span direction and restraining the displacement in the girder direction is temporarily fixed to the upper end of the column so as to be movable in the span direction, and then the beam main body is fixed to the lower end of the column member with the column. It is bridged between the pillars by supporting it at the upper end, and then the chord member is tensioned to introduce tension to the beam main body, and the guide member is moved in the span direction according to the displacement amount of the beam main body. Align the pin insertion holes It is allowed, after rotatably connected to their pin insertion holes to insert the pin guide members the beam body, stringing beam method construction, characterized in that to fix the guide member to the upper end of the column.