JP5879190B2 - Construction method of stringed beam structure - Google Patents

Description

  The present invention relates to a construction method for a stringed beam structure.

  Conventionally, in order to realize a large span space, a frame-shaped outer peripheral beam, a plurality of upper chord beams installed between opposite sides of the outer peripheral beam, and a plan view arranged inside the outer peripheral beam And a plurality of second lower chord beams extending radially from the first lower chord beam and connected to an outer peripheral beam (see Patent Documents 1 and 2).

In such a stringed beam structure, the procedure for introducing tension into the first lower string beam and the second lower string beam is as follows.
That is, the annular first lower chord beam is disposed and the second lower chord beam is connected to the outer circumferential beam. Next, a jack is installed in all the connection places of the first lower chord beam and the second lower chord beam. Next, these jacks are driven synchronously to shorten the length of each second lower chord beam extending radially, thereby introducing tension into the first lower chord beam and the second lower chord beam (Patent Document 2). Paragraph numbers [0034] and [0035]).

JP 2011-47136 A Japanese Patent No. 3338146

  However, in the above-described method, it is necessary to prepare a number of jacks equal to the number of the second lower chord beams, and to drive these many jacks in synchronization, so that there is a problem that costs and labor are required. It was.

  It is an object of the present invention to provide a construction method for a stringed beam structure that can easily introduce tension to both the lower stringed beams with respect to the stringed beam structure having an annular first lower stringed beam and a second radially extending lower stringed beam. .

  The construction method of the stringed beam structure according to claim 1 includes a frame-shaped outer peripheral beam (for example, an outer peripheral beam 3 described later) and a plurality of upper chord beams (a plurality of upper chord beams installed between the opposing portions of the outer peripheral beam). For example, an upper chord beam 4) described later, an annular first lower chord beam (for example, a structural cable 10 described later) disposed inside the outer peripheral beam, and a radial extension from the first lower chord beam. A construction method of a stringed beam structure (for example, a later-described stringed beam structure 1) including a plurality of second lower stringed beams (for example, a tie rod 20 described later) connected to the outer circumferential beam, and dividing the first lower stringed beam And introducing a design tension to each of the divided first lower chord beams, and marking a connection position of each of the divided first lower chord beams to each of the divided second lower chord beams in this state; The divided first lower chord beams inside the outer beam Connecting the second lower chord beam to the marked position of the first lower chord beam, adjusting the length of the second lower chord beam, and the divided first lower chord beams And the step of bringing the ends of the divided first lower chord beams close to each other and introducing tension to the first lower chord beam and each of the second lower chord beams.

  The construction method of the stringed beam structure according to claim 2 is characterized in that the first lower chord beam is divided into two, and the two divided first lower chord beams are connected at two locations.

According to the present invention, at the connection portion between the divided first lower chord beams, the ends of the divided first lower chord beams are brought close to each other, thereby introducing tension to the first lower chord beam and each second lower chord beam. .
That is, when the ends of the divided first lower chord beams are brought close to each other, the divided first lower chord beams are constrained by the second lower chord beam, so that tension is introduced into the first lower chord beam.
Further, when the ends of the divided first lower chord beams are brought close to each other, the inner diameter of the annular first lower chord beam is narrowed, so that each second lower chord beam is pulled inward by the first lower chord beam and each second lower chord beam is pulled. Tension is introduced into the beam.

  Therefore, the number of jacks can be greatly reduced compared to the case where tension is simultaneously introduced to all the connecting portions of the first lower chord beam and the second lower chord beam as in the prior art, so the cost and labor can be greatly reduced. The tension can be easily and uniformly introduced into both the first lower chord beam and the second lower chord beam.

Here, before introducing the tension, a design tension is introduced in advance to the divided first lower chord beam, and in this state, a connection position with the second lower chord beam is marked on the divided first lower chord beam. The second lower chord beam was connected to the marked position of the first lower chord beam.
When the design tension is introduced to the divided first lower chord beam, the divided first lower chord beam exhibits the same elongation as when the tension is actually introduced. Therefore, by marking in this state, The elongation, that is, the tension introduced into the second lower chord beam can be managed with high accuracy.

In the construction method of the stringed string structure of the present invention , an insertion hole (for example, an insertion hole 222 described later) through which the first lower chord beam is inserted is formed in the second lower chord beam, and tension is applied to the first lower chord beam. Before introduction, it is preferable to temporarily fix a pair of anti-slip jigs (for example, anti-slip jigs 60 described later) to the first lower chord beam with the second lower chord beam interposed therebetween.

If tension is introduced into the first lower chord beam, the second lower chord beam may be displaced from a predetermined position (that is, the marked position), and the stringed beam structure may become structurally unstable.
However, according to the present invention, since the pair of anti-slip jigs is temporarily fixed with the second lower chord beam sandwiched between the first lower chord beam, even if the second lower chord beam attempts to move relative to the first lower chord beam, The second lower chord beam is caught by the anti-slip jig. Therefore, it is possible to prevent the position of the second lower chord beam from being displaced and prevent the stringed beam structure from becoming structurally unstable.

  In the step of connecting the divided first lower chord beams into an annular shape, it is preferable that the first lower chord beam is suspended and supported from the upper chord beam by a temporary suspension member (for example, a temporary suspension member 50 described later).

  According to the present invention, the first lower chord beam is suspended and supported from the upper chord beam by the temporary suspension material, the height is adjusted, and then the tension is introduced into the first lower chord beam. Therefore, it is possible to ensure the structural stability of the first lower chord beam and the second lower chord beam when the tension is introduced.

According to the present invention, the number of jacks can be greatly reduced as compared with the conventional case where tension is simultaneously introduced to all the connecting portions of the first lower chord beam and the second lower chord beam. Can be greatly reduced, and tension can be easily and uniformly introduced into both the first lower chord beam and the second lower chord beam.
By positioning the second upper chord beam with a non-slip jig, it is possible to suppress the relative position of the first lower chord beam and the second lower chord beam from being disturbed when the tension is introduced, and to introduce the tension stably and uniformly.

It is the top view and side view of a stringed beam structure which concern on one Embodiment of this invention. It is a top view of the joint part of the 1st lower chord beam of the string beam structure which concerns on the said embodiment. It is the top view and side view of a 2nd lower chord beam of the stringed beam structure which concern on the said embodiment. It is a side view of the suspension material used for the stringed beam structure according to the embodiment. It is a side view of the temporary suspension member used for the stringed beam structure according to the embodiment. It is the side view and back view of a non-slip jig | tool used for the tension string beam structure which concerns on the said embodiment. FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a plan view and a side view of a stringed beam structure 1 according to an embodiment of the present invention.

  The stringed beam structure 1 includes a plurality of columns 2 arranged in a rectangular shape, a rectangular frame-shaped outer circumferential beam 3 installed between the heads of these columns 2, and between the opposite sides of the outer circumferential beam 3. A plurality of installed upper chord beams 4, a structural cable 10 as a first lower chord beam that is annular in plan view disposed inside the outer circumferential beam 3, and the outer circumferential beam 3 extending radially from the structural cable 10. Are provided with a plurality of tie rods 20 as second lower chord beams, and a plurality of suspension members 30 for suspending and supporting the structural cable 10 from the upper chord beam 4.

The structural cable 10 is divided into two divided cables 10 </ b> A and 10 </ b> B, and the ends of the two divided cables 10 </ b> A and 10 </ b> B are connected to each other at two locations by a joint portion 40.
Further, a work stage 5 is provided by a frame scaffold about 1 m below the structural cable 10.

FIG. 2 is a plan view of the joint portion 40 of the structural cable 10.
The joint portion 40 includes a socket 41A attached to the end of the split cable 10A, a socket 41B attached to the end of the split cable 10B, and a rod-shaped joint rod 42 that connects the socket 41A and the socket 41B.

Male screw portions 421 opposite to each other are formed on both ends of the joint rod 42, and female screw portions 411 into which the male screw portions 421 of the joint rod 42 are screwed are formed in the sockets 41A and 41B.
According to the joint portion 40, the socket 41A and the socket 41B are moved closer to or away from each other by rotating the joint rod 42.

FIG. 3 is a plan view and a side view of the tie rod 20.
The tie rod 20 includes a tie rod main body 21 extending in a rod shape, a cable connecting portion 22 rotatably provided on the proximal end side of the tie rod main body 21 and connected to the structural cable 10, and provided on the distal end side of the tie rod main body 21. And a beam connecting portion 23 connected to the outer peripheral beam 3.

The cable connecting portion 22 has a U-shaped cross section, and the tip ends of the cable connecting portion 22 are connected by pins 221. Inside the cable connecting portion 22 is an insertion hole 222 through which the structural cable 10 is inserted.
The pin 221 extends in a direction substantially orthogonal to the axial direction of the structural cable 10, and the tie rod body 21 and the cable connecting portion 22 can be rotated about the pin 221 as a rotation axis.

The beam connecting portion 23 has a U-shaped cross section, and the distal end sides of the beam connecting portion 23 are connected by pins 231. The outer peripheral beam 3 is sandwiched inside the beam connecting portion 23, and the pin 231 passes through the outer peripheral beam 3.
The pin 231 extends substantially parallel to the axial direction of the structural cable 10, and the tie rod body 21 and the structural cable 10 can be rotated about the pin 231 as a rotational axis.

  An internal thread portion 232 is formed on the base end side of the beam connecting portion 23. On the other hand, a male threaded portion 211 is formed on the distal end side of the tie rod body 21, and the male threaded portion 211 of the tie rod body 21 is screwed into the female threaded portion 232.

FIG. 4 is a side view of the suspension member 30.
The suspension member 30 includes a rod 31 that is penetrated and fixed to the flange of the upper chord beam 4 by a bolt, and a cable support portion 32 that is provided at the lower end of the rod 31 and supports the structural cable 10.
The cable support portion 32 is a substantially U-shaped support portion main body 321, a pin 322 that connects the front end sides of the support portion main body 321, and a band that is attached to the lower end of the support portion main body 321 and supports the structural cable. 323.

  The lower end portion of the rod 31 is sandwiched between the support portion main body 321, and the pin 322 extends substantially horizontally and penetrates the rod 31. Thereby, the rod 31 and the cable support part 32 can be rotated around the pin 322 as a rotation axis.

  Next, a procedure for introducing tension into the structural cable 10 and the tie rod 20 of the stringed beam structure 1 will be described.

In Step 1, split cables 10A and 10B obtained by dividing the structural cable 10 into two are prepared at the factory, and design tension is introduced into each of the split cables 10A and 10B. In this state, the split cables 10A and 10B are provided. The connecting position with each tie rod 20 is marked on each of the above.
In step 2, the work frame 5 is constructed by assembling the frame scaffolding at the site, and the steel frame of the column 2, the outer peripheral beam 3, and the upper chord beam 4 is constructed.
Here, the framework scaffold of the work stage 5 also serves as a support for temporarily supporting the upper chord beam 4.

  In step 3, the divided cables 10 </ b> A and 10 </ b> B are connected to each other by the joint portion 40 on the work stage 5 inside the outer peripheral beam 3 to form an annular shape, and the annular structural cable 10 is separated by, for example, a 5 m grid. The height of the structural cable 10 is adjusted by suspending and supporting from the upper chord beam 4 every time.

FIG. 5 is a side view of the temporary suspension member 50.
The temporary suspension member 50 includes a nylon sling 51 hooked on the upper chord beam 4, a lever block (registered trademark) 52 attached to the lower end of the nylon sling 51, and a structural cable attached to the lever block 52 inside. And an annular member 53 through which 10 is inserted.
According to the temporary suspension member 50, the height of the structural cable 10 is adjusted by adjusting the length of the lever block 52 while relaxing the impact during suspension by the nylon sling 51.

  In step 4, each tie rod 20 is connected to the marked position of the structural cable 10 on the work stage 5, and a pair of anti-slip jigs 60 is sandwiched between the structural cable 10 and the cable connecting portion 22 of each tie rod 20. Temporarily fix.

FIG. 6 is a rear view and a plan view of the anti-slip jig 60.
The anti-slip jig 60 includes a pair of jig bodies 61 arranged with the structural cable 10 interposed therebetween, and a pair of bolts 62 that connect the jig bodies 61 to each other. According to the anti-slip jig 60, the structural cable 10 is strongly held by the jig body 61 by tightening the bolt 62.

  In step 5, the length of each tie rod 20 is adjusted. Specifically, the length of the tie rod 20 is adjusted by adjusting the screwing depth of the tie rod body 21 with respect to the beam connecting portion 23.

In step 6, tension is introduced into the structural cable 10 by the joint portion 40, and thereby, tension is also introduced into each tie rod 20.
That is, the joint cable 42 and the tie rod are rotated by rotating the joint rod 42 while bringing the ends of the divided cables 10A and 10B close to each other with the jack (not shown) at the joint portion 40 at the connecting portion between the divided cables 10A and 10B. Tension is introduced into 20.

Here, the operation of introducing tension into the structural cable 10 is performed according to the following procedure.
First, 40% of the design tension is introduced into the structural cable 10 to check the tension of the structural cable 10 and each tie rod 20. When the tension of the tie rod 20 is out of the control value, the length of the tie rod is finely adjusted.
Next, 80% of the design tension is introduced into the structural cable 10, and the tension of the structural cable 10 and each tie rod 20 is measured and confirmed.
Finally, 100% of the design tension is introduced into the structural cable 10 and the tension of the structural cable 10 and each tie rod 20 is measured and confirmed.

  In step 7, the anti-slip jig 60 is removed and the temporary suspension member 50 is replaced with the suspension member 30.

According to this embodiment, there are the following effects.
(1) Tension was introduced into the structural cable 10 and the tie rods 20 by bringing the ends of the divided cables 10A and 10B closer to each other with a jack at the connection location between the divided cables 10A and 10B.
That is, when the end portions of the split cables 10A and 10B are brought close to each other, the split cables 10A and 10B are restrained by the tie rod 20, so that tension is introduced into the structural cable 10.
Further, when the ends of the split cables 10A and 10B are brought close to each other, the inner diameter of the annular structural cable 10 is narrowed, so that each tie rod 20 is pulled inward by the structural cable 10 and tension is introduced into each tie rod 20. Is done.

  Therefore, the number of jacks can be greatly reduced compared to the case where tension is simultaneously introduced to all the connecting portions of the first lower chord beam and the second lower chord beam as in the prior art, so the cost and labor can be greatly reduced. The tension can be easily and uniformly introduced into both the structural cable 10 and the tie rod 20.

Here, before introducing the tension, design tension is introduced in advance to the split cables 10A and 10B, and in this state, the connection position with the tie rod 20 is marked on the split cables 10A and 10B. The tie rod 20 was connected to 10 marked positions.
When design tension is introduced into the split cables 10A and 10B, the split cables 10A and 10B exhibit the same elongation as when the tension is actually introduced. Therefore, by marking in this state, the extension of the tie rod 20, that is, the tie rod 20 The tension introduced into the can be managed with high accuracy.

  (2) The tie rod 20 is relatively moved with respect to the structural cable 10 by temporarily fixing the anti-slip jig 60 so as to sandwich the pair of cable connecting portions 22 of the tie rod 20 connected to the structural cable 10. Even so, the tie rod 20 is caught by the anti-slip jig 60. Therefore, it is possible to prevent the tie rod 20 from being displaced and prevent the stringed beam structure 1 from becoming structurally unstable.

  (3) The structural cable 10 is suspended and supported from the upper chord beam 4 by the temporary suspension member 50, and after adjusting the height, tension is introduced into the structural cable 10. Therefore, it is possible to ensure the structural stability of the structural cable 10 and the tie rod 20 when the tension is introduced.

  (4) Since the framework scaffolding of the work stage 5 for attaching the structural cable 10 and the tie rod 20 also serves as a support for temporarily supporting the upper chord beam 4, the temporary cost can be reduced and the construction efficiency can be reduced. Can be improved.

  It should be noted that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within a scope that can achieve the object of the present invention are included in the present invention.

DESCRIPTION OF SYMBOLS 1 ... String beam structure 2 ... Column 3 ... Outer beam 4 ... Upper chord beam 5 ... Work stage 10 ... Structural cable (1st lower chord beam)
10A, 10B ... Split cable 20 ... Tie rod (second lower chord beam)
DESCRIPTION OF SYMBOLS 21 ... Tie-rod main body 22 ... Cable connection part 23 ... Beam connection part 30 ... Suspension material 31 ... Rod 32 ... Cable support part 40 ... Joint part 41A, 41B ... Socket 42 ... Joint rod 50 ... Temporary suspension material 51 ... Nylon sling 52 ... Lever block 53 ... annular member 60 ... anti-slip jig 61 ... jig main body 62 ... bolt 211 ... male screw part 221 ... pin 222 ... insertion hole 231 ... pin 232 ... female screw part 321 ... support part main body 322 ... pin 323 ... band 411 ... Female thread 421 ... Male thread

Claims (2)

A frame-shaped outer circumferential beam, a plurality of upper chord beams laid between mutually facing portions of the outer circumferential beam, a first lower chord beam that is annular in plan view disposed inside the outer circumferential beam, and A plurality of second lower chord beams extending radially from the first lower chord beam and connected to the outer circumferential beam,
Before laying the first lower chord beam, the first lower chord beam is divided, and design tension is introduced in advance to each of the divided first lower chord beams, and in this state, the divided first lower chord beam Marking each of the connecting positions with each of the second lower chord beams;
Connecting the divided first lower chord beams inside the outer peripheral beam to form an annular shape;
Connecting the second lower chord beam to the marked position of the first lower chord beam and adjusting the length of the second lower chord beam;
Sandwiching each second lower chord beam with a pair of anti-slip jigs and temporarily fixing the second lower chord beam;
At the connection location of the divided first lower chord beams, the ends of the divided first lower chord beams are brought close to each other to introduce a tension into the first lower chord beam multiple times, and the second lower chord beam And a step of introducing a predetermined tension by adjusting a length of the beam and introducing the design tension to the first lower chord beam .   2. The construction method of the stringed beam structure according to claim 1, wherein the first lower chord beam is divided into two parts, and the two divided first lower chord beams are connected to each other at two locations.

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