JP4003444B2 - Support method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a support method suitable for use in, for example, a joint groove of a closed type no-maintenance structure in which a transfer pipe for radioactive material fluid is accommodated.
[0002]
[Prior art]
For example, the common groove in which the radioactive material fluid transfer pipe is accommodated is a sealed type called an active trench, and thus has a no-maintenance structure incapable of entering and exiting after completion. As a frame construction method in this type of structure, when the bottom plate and the side wall are completed, a piping contractor performs internal piping work, and after the piping work is completed, the top plate is constructed.
[0003]
As such a conventional top plate construction, a method of supporting with a receiving girder of a corrosion-resistant material (SUS304) and a deck plate after storage piping work has been used. FIGS. 8 and 9 show the structure. The trench 1 is composed of a bottom slab 2 and left and right side walls 3. The deck plate 5 is arranged on the receiving beam 4 to close the upper opening, and concrete is placed on the upper plate 6 to construct the top plate 6.
[0004]
[Problems to be solved by the invention]
However, in the above construction method, since the stress generated in the receiving beam 4 is structurally large, it is necessary to use H-section steel with a large cross section as shown in FIG. It was.
(1) In order to secure the inner cross-section of the trench, the cross-sectional height H of the entire structure increases as the beam formation of the receiving beam 4 increases.
(2) When the cross-sectional height H of the entire structure is increased, external problems such as a construction space due to an upper limit may occur.
(3) Although it is a separate element from the support, if the supporting member thickness is large, of the rebar assembly work for the floor and top plate, a rebar mount for assembling the top rebar of the top plate is necessary, which increases costs. At the same time, it was a cause of construction delay.
[0005]
The present invention has been made in order to solve the above-mentioned problems, and the object thereof is to reduce the beam formation as a receiving beam and to reduce the size of the entire structure in order to secure the same inner cross section. Thus, a support method that can speed up the construction and reduce the cost is provided by using the receiving girder as the reinforcing bar.
[0006]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a plurality of lower chord members made of H-shaped steel at both ends of a plurality of deck plates covering a top opening of a pair of side walls at predetermined intervals. Is installed on the lower flange of each lower chord material, and the lower rebar of the top plate is laid on the lower chord material, and then a truss frame constituting a receiving girder together with the lower chord material is assembled to the lower chord material, This is a support method in which a truss frame is used as a reinforcing bar base and the top rebar of the top slab is placed on top of it, and then the top slab is constructed by placing concrete. One side of the lower flange is used as the lower chord material at the end of the block. An H-shaped steel whose part is longer than the other side part is used . Therefore, in the construction method of the present invention, the lower chord material has a cross-sectional performance capable of supporting the construction load as a simple beam before the truss frame is assembled, and then the truss frame is assembled to provide sufficient strength to support the entire load. Constitutes a girder that expresses In addition, the truss frame functions as a reinforcing bar mount, and the top plate upper reinforcing bar can be assembled in the upper part of the truss frame.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is a cross-sectional view of an active trench to which the method of the present invention is applied, and FIG. 2 is a cross-sectional view taken along line AA of FIG. In addition, the same code | symbol is used and demonstrated to the same location as the past.
[0009]
The active trench 10 in the figure includes a plurality of lower chord members 12 arranged at predetermined intervals on the upper opening surface of the assembly composed of the already finished bottom plate 2 and left and right side walls 3. A deck plate 14 that is spanned between the lower flanges of the lower chord material 12 and covers the upper side wall (the bottom surface of the top plate); a truss frame 16 that is integrally assembled on the lower chord material 12; A connecting steel member 17 connected to the lower chord member 12, a lower side reinforcing bar 18 vertically and horizontally arranged on the upper part of the lower chord material 12, and an upper side reinforcing bar 20 vertically and horizontally arranged on the upper part of the truss frame 16. The top plate 22 is constructed by placing concrete in the upper space.
[0010]
Before the truss frame 16 is assembled, the lower chord member 12 has a cross-sectional performance capable of supporting a construction load (a temporary placement load of a reinforcing bar and an impact load on construction) as a simple beam, and then the truss frame 16 is assembled. Thus, a receiving girder that expresses sufficient strength to support the entire load is configured.
[0011]
FIGS. 3A to 3D show cross sections of the lower chord material 12. The lower chord material 12 is made of H-shaped steel, and the lower flange 12a supporting the deck plate 14 is made of SUS304 having corrosion resistance. It is constructed and integrated by welding, (a) is a member used for the general part, (b) is a member used for the end of the block, one side of the lower flange 12a is extended, The filling of concrete is ensured.
[0012]
Further, (c) and (d) are members used for the branch portion of the active trench 10, and the beam thickness is made lower by increasing the material thickness than (a) and (b). In other words, at the bifurcation, the main part of the trench body (rebar in the cross section of the trench body) of the lower-side reinforcing bars and the lower part of the bifurcation part arranged in the direction orthogonal to the reinforcing bars can be arranged without interference. The cross section performance equivalent to that of general lower chord material is obtained by lowering the thickness and increasing the material thickness. Furthermore, in any member, a pair of bolt holes 12c for connection to the truss frame 16 is formed through the upper flange 12b.
[0013]
The truss frame 16 is a panel manufactured by integrally assembling a plurality of vertical members, upper chord members and diagonal members, and is built on the lower chord member 12 by a crane at the site. The upper flange 12b is integrated with a bolt and nut. Also, the upper sides of each truss frame 16 are also connected to each other via a connecting steel material 17 at the site. In the assembled state, the truss frame 16 is formed in a box-shaped frame shape to reinforce the lower chord material 12 and to assemble the upper rebar. Also used as a steel frame mount.
[0014]
4 (a) and 4 (b) show a connecting portion between the truss frame 16 and the lower chord member 12, and a seat plate 16b is integrally welded to the bottom surface of a vertical member 16a made of H-shaped steel. A bolt B is inserted into a bolt hole formed on both sides corresponding to the flange 12b and fastened with a nut N, so that the upper chord 12 is firmly connected and integrated with the upper flange 12b. In particular, as shown in (a), the reinforcing plates 16d are integrated on both sides of the web by welding at a place where a large stress is applied, such as a joint between the vertical member 16a and the diagonal member 16c. In order to reinforce the stress.
[0015]
Next, the construction procedure in the above structure will be described with reference to FIGS. First, as shown in FIG. 5A, the lower chord members 12 are arranged orthogonally on the side wall 3 of the trench where the internal piping work (not shown) is completed. Next, as shown in (b), the deck plate 14 is laid between the lower flanges 12 a of the lower chord material 12. Thereafter, as shown in (c), the top plate lower reinforcing bar 18 is arranged vertically and horizontally on the upper flange 12 b of the lower chord member 12.
[0016]
Next, as shown in FIG. 6 (d), the truss frame 16 is built on the lower chord member 12 using a crane or the like, and is assembled on the lower chord member 12 with bolts and nuts. Are connected by a connecting steel material 17 (not shown). Next, as shown in (e), the top plate upper reinforcing bar 20 is arranged with the upper part of the truss frame 16 as the reinforcing bar assembly frame.
[0017]
Then, as shown in FIG. 7F, the top formwork 24 is assembled on both sides of the both side walls 3 and cleaning is performed before placing, and then the concrete C is placed in the formwork 24 as shown in FIG. Set up. At this time point, the lower chord member 12 is integrated with the truss frame 16, so that a sufficient strength is exerted to support the entire load. Then, after a sufficient curing period, as shown in (h), if the formwork 24 is disassembled, the top plate 22 is completed, and the construction of the closed active trench 10 is completed.
[0018]
【The invention's effect】
As is apparent from the above description, according to the reinforcing bar-supporting girder supporting method according to the present invention, the beam formation as the receiving girder can be reduced, and the entire structure for securing the same inner air cross section can be achieved. Can be miniaturized. Further, in the present invention, the assembled truss frame is also used as a reinforcing bar frame, thereby speeding up construction and reducing costs.
[Brief description of the drawings]
FIG. 1 is a front sectional view of an active trench to which a method of the present invention is applied.
FIG. 2 is a side sectional view taken along line AA in FIG.
FIGS. 3A to 3D are enlarged cross-sectional views of various lower chord members in part B of FIG.
4 (a) and 4 (b) are enlarged views showing a connection form of the truss frame and the lower chord member in the C part and the D part of FIG. 1;
FIGS. 5A to 5C are cross-sectional views for explaining the construction procedure of the method of the present invention.
6 (d) to (f) are cross-sectional views for explaining a construction procedure subsequent to FIG.
7 (g) and (h) are cross-sectional views for explaining a construction procedure subsequent to FIG.
FIG. 8 is a front sectional view showing a structure of a conventional active trench.
9 is a side sectional view taken along the line II of FIG.
[Explanation of symbols]
3 Side wall 10 Active trench 12 Lower chord material 14 Deck plate 16 Truss frame 18 Top plate lower rebar 20 Top plate upper rebar 22 Top plate

Claims (1)

Both ends of a plurality of lower chord members made of H-shaped steel are installed on top of a pair of side walls at a predetermined interval, and both ends of a plurality of deck plates covering the upper openings of the side walls are installed on the lower flange of each lower chord member. After placing the lower reinforcing bar of the top plate on the lower chord material, a truss frame that constitutes a receiving girder together with the lower chord material is assembled to the lower chord material, and then the truss frame is placed on the upper portion of the truss frame as a reinforcing bar mount. This is a support method in which a top plate is constructed by placing concrete after placing the upper rebar of the plate, and as a lower chord material at the end of the block, one side of the lower flange extends from the other side. A support method characterized by using

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