JPH09310441A - Roof constructing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the cross sectional area of a timbering member. SOLUTION: A roof 16 is in a double layer structure of a lower side rood 18 and an upper side rood 20. The lower side roof 18 is formed with a number of precast concrete panels 22 for which the dome roof 16 to be constructed is divided into segments and the upper side roof 20 of formed of site-placed concrete. The panels 22 are arranged on a timbering for a number of those to be in mutual contact in the peripheral and radial directions and so plural concentric rings 241 -248 are formed in the closely arranged condition. The panels 22 arranged along the radial direction are mutually connected with bolts and nuts. Between the panels 22 arranged along the peripheral direction, prestress force is introduced along the same direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roof building method, and more particularly to a dome-shaped roof building method.

[0002]

2. Description of the Related Art LNG tanks, oil storage tanks, large-scale sports facilities, etc. having a side wall formed in an annular shape and a dome-shaped roof having an outer peripheral edge fixed to the upper end of the side wall. Various types of methods have been conventionally proposed as a method for constructing a roof of a large-scale structure, and the following three methods are known as typical methods.

First, the first method is to construct a roof with a bottom slab, lift it, and fix it to the side wall. The second method is to construct a roof on the support after the support is installed inside the side wall. In the third method, after the roof is assembled on the bottom slab, the roof is floated to a predetermined position by air, and the peripheral edge of the roof is fixed to the upper end side of the side wall portion. However, these roof construction methods have the technical problems described below.

[0004]

That is, in the first and second methods, since the roof load becomes very large, the lifting material for lifting and the cross section of the supporting structure become large, which increases the cost. become. In addition, in the third method, it is difficult to maintain the balance of the roof because the compressed air is blown to float, and in order to float while supporting the roof load, a very large amount of air and pressure are required. However, there is a problem in that the equipment becomes large and the cost becomes high even with this method.

The present invention has been made in view of such conventional problems, and it is an object of the present invention to provide a low cost roof structure and a method of constructing a roof.

[0006]

In order to achieve the above object, the present invention is a method for constructing a roof in which a dome-shaped roof is erected on the upper end side of a cylindrical side wall portion, wherein the roof is integrally formed. Two-layered lower and upper roof parts, wherein the lower roof part is composed of a large number of precast concrete panels obtained by dividing the dome-shaped roof into segments, and the lower roof is formed inside the side wall. Constructing an annular supporting structure for supporting a part, pulling up the constructed supporting structure to support it on the upper end side of the side wall, and arranging the panel adjacent to the upper surface side of the supporting structure in the circumferential and radial directions, A prestressing force is introduced between the panels adjacently arranged along the circumferential direction in a state where the panels adjacently arranged along the direction are connected to each other, and thereafter, the precast concrete panel As mold, and Da設 concrete on top side, and to form the upper roof part. According to the roof construction method configured as described above,
Since the panel made of precast concrete is also used as a part of the formwork, the work for removing the formwork is omitted. Also, when pouring concrete on the upper roof part, the panel becomes self-supporting due to the dome effect due to the prestressing force introduced in the circumferential direction of the panel, so the support work is
Since it suffices to support only the load applied when the panel is laid, the cross-sectional area of the member can be reduced accordingly.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1 to 9 show an embodiment of a method for constructing a roof according to the present invention. The roof structure shown in the figure is a case where the present invention is applied to a roof portion of an underground tank 10 as shown in FIG. 9, and the underground tank 10 has a sidewall 12 constructed in the ground.
The bottom plate 14 is integrally constructed on the inner peripheral side of the lower end of the side wall 12, and the dome-shaped roof 16 is installed on the upper end side of the side wall 12 and has a circular planar shape.

The side wall 12 is formed in the shape of a hollow cylinder. The side wall 12 is constructed from the ground by, for example, an underground continuous wall method, and after excavating the inside thereof, a disk shape is formed on the inner peripheral side of the side wall 12. Bottom plate 14 is formed. Roof 16
In this embodiment, the lower roof portion 18 and the upper roof portion 20 have a two-layer structure. The lower roof part 18 is composed of a large number of precast concrete panels 22 obtained by dividing the dome-shaped roof 16 to be constructed into segments, and the upper roof part 20 is composed of cast-in-place concrete.

In constructing the roof 16, first, referring to FIG.
As shown in FIG. 5, a dome-shaped supporting structure 28 is constructed. The supporting work 28 is performed using a temporary frame 30 installed on the bottom plate 14 inside the side wall 12. In this embodiment, the dome-shaped support 28 employs a steel truss structure, and the support blocks 28a divided in the circumferential and radial directions are hung by a crane and placed on the temporary frame 30 to support the support. The work blocks 28a are connected to each other by bolts and nuts or welding, and assembled into a dome shape. When the support work 28 is assembled, as shown in FIG. 2, the lifting device 32 is used to pull up the support work 28.

In the lifting device 32 of this embodiment, specifically, a zelkova installed on the upper end of the side wall 12 is used, and this jack has an appropriate interval along the circumferential direction of the side wall 12. Then, a plurality of wires are installed and pulled up by the wires 34 locked to the outer peripheral edge of the supporting structure 28 assembled in a dome shape. Then, when the supporting work 28 is pulled up to a predetermined position on the upper end side of the side wall 12, the supporting work 2 is carried out by attaching a wedge to the wire 34 and locking it.
8 is supported on the upper end side of the side wall 12.

When the support of the support work 28 is completed,
The precast concrete panel 22 is installed on the support 28. FIG. 3 shows a working state when the panel 22 is installed.
It is hung by a crawler crane 36 arranged outside 2 and arranged at a predetermined position. The precast concrete panel 22 is obtained by dividing the dome-shaped roof 16 into segments as shown in FIG. 4 as a whole, and a plurality of them are closely contacted with each other in the circumferential and radial directions. In this embodiment, a plurality of concentric ring portions 24 _{1 to} 24 ₈ are formed in a closely arranged state. In this embodiment, a total of 8 ring portions 24 _{1 to} 24 ₈ are formed from the center. Has been done.

The panels 22 arranged along the radial direction are interconnected by bolts and nuts. Also,
A prestressing force is introduced between the panels 22 arranged along the circumferential direction along the direction. Ring part 2
It is shown in FIGS. 5 to 8 the portion of the precast concrete panel 22 to form a 4 _{1-24 8.} The panel 22 shown in the figure is formed into a shape in which the ring portions 24 _{1 to} 24 ₈ are divided at equal angular intervals from the center and are cut in a substantially parallel vertical direction, and a reinforcing bar is embedded inside.

The panel 22 has a flat plate-shaped base portion 22a and substantially H-shaped convex portions 22b to 22e integrally provided on the upper surface side of the base portion 22a, and the convex portions 22b to 22e.
Is a pair of first and second protrusions 22b,
22c and third and fourth convex portions 22d extending in the circumferential direction,
22e. On the four rounds of panel 22,
Four steel plates 22f are arranged so as to cover the edges of the base portion 22a and the first to fourth convex portions 22b to 22e.
A bolt box 22g having an open upper end is provided at each of both end edges of the first and second convex portions 22b and 22c extending in the radial direction. The steel plate 22f closing one end of the bolt box 22g has a panel 22. An insertion hole 22h for a bolt that is used to connect the two in the radial direction is formed.

Third and fourth convex portions 22 extending in the circumferential direction
Connection boxes 22i each having an open upper end are provided at both end edges of the d and 22e, and a steel plate 22f closing one end of the connection box 22i is provided when a prestressing force is introduced into the ring portion. Each of the steel material insertion holes 22j to be used is formed. In addition, in the third and fourth convex portions 22d and 22e, the convex portions 22d and 22
A hollow tubular sheath tube 22k having both ends opened so as to communicate between the connection boxes 22i located on both end sides of e
Is buried.

Further, at the four corners on the lower surface side of the base portion 22a,
A screw hole 22l is provided. This screw hole 22l
As shown in FIG. 5, when the panels 22 are closely arranged to form a dome shape, the adjustment bolts 26 are screwed and used to adjust the height between the panels 22. When arranging each panel 22 on the support work 28, each panel 22
The height adjusting bolts 26 are screwed into the screw holes 22l provided at the four corners of the bracket to adjust the height to a predetermined angle (see FIG. 7).

The plurality of panels 22 are arranged in close contact with each other in the circumferential and radial directions in a state where the height is adjusted, and form concentric ring portions 24 _{1 to} 24 ₈ so that the lower side of the dome shape is formed. The roof portion 18 is formed. This state is shown in FIG. Then, the panels 22 closely arranged along the radial direction are connected to each other at a stage where a plurality of or all of them are arranged. The connection at this time is performed by inserting a bolt through the bolt box 22g into the bolt insertion hole 22h between the panels 22 adjacent in the radial direction and screwing a nut.

Then, after this, a prestressing force is introduced between the panels 22 closely arranged along the circumferential direction. This prestressing force is introduced by inserting a steel material into the sheath tube 22k embedded in each panel 22 through the connecting box 22i and pulling and fixing the steel material. In this case, the fixing portion of the steel material is performed so that the steel material extends between two or more panels 22, and, for example, although the diameter of the roof 16 is relatively small, although it depends on the size of the roof 16, It is also possible to arrange one steel material in an annular shape in the ring portion on the inner peripheral side having a short peripheral length.

When the prestressing force is introduced into the lower roof portion 18, the dome effect ensures the independence of this portion, so that the supporting work 28 can be removed at this stage. However, from the viewpoint of safety and workability, it is desirable that the support work 28 is provided at a position spaced downward from the lower surface of the lower roof portion 18 until the construction of the roof 16 is completed.

When the lower roof portion 18 is constructed in this manner, the dome-shaped lower roof portion 18 is used as a formwork.
The upper side of the upper roof portion 20 is formed integrally with the lower roof portion 18 by providing reinforcement on the upper side and pouring concrete (see FIG. 9). Then, when the supporting work 28 is dismantled and removed, the construction is completed. According to the method of constructing the roof 16 configured as described above, the panel 2 made of precast concrete is used.
Since 2 is also used as a part of the formwork when forming the upper roof portion 20, the labor for removing the formwork is omitted.

When pouring concrete on the upper roof portion 20, the panel 22 becomes self-supporting due to the dome effect due to the prestressing force introduced in the circumferential direction of the panel 22, so that the supporting work 28 is performed by the panel 22. Since it suffices to support only the load at the time of laying, the cross-sectional area of the member can be reduced accordingly. Furthermore, in the roof construction method having the above-mentioned configuration, the panel 2 made of precast concrete is used.
2 has a two-layer structure in which the concrete cast on site and the concrete cast on site are integrated, and since the projections 22b to 22e are formed on each panel 22, the concrete cast on site and the panel 22 are joined in an uneven shape. , The contact area is increased, and the integrity between the two can be enhanced.

The convex portion 22b formed on each panel 22
22e can be replaced by roughening or projecting a dowel. Further, in the above-described embodiment, the case where the present invention is applied to the underground tank 10 is illustrated, but the implementation of the present invention is not limited to this, and may be applied to a tank above ground or semi-underground, a large sports facility, or the like. Of course, it can be applied.

[0022]

As described above in detail in the embodiments,
According to the roof construction method of the present invention, the following effects can be obtained. Since the precast concrete panel is also used as a part of the form when forming the upper roof part, the work of removing the form is omitted. When prestressing force is introduced into the precast concrete panel, it becomes self-sustaining due to the dome effect,
The load burden on the supporting work and the lifting device is reduced, the cross-sectional area of the supporting member is small, and it is economical. Providing a convex portion on the upper surface side of the precast concrete panel can strengthen the integrity with the upper roof portion formed by casting in-situ.

[Brief description of drawings]

FIG. 1 is a cross-sectional explanatory view showing a first step of a method for constructing a roof according to the present invention.

FIG. 2 is a cross-sectional explanatory diagram of a process performed subsequent to the process of FIG.

FIG. 3 is an explanatory cross-sectional view of a step performed subsequent to the step of FIG. 2;

FIG. 4 is a perspective view of a lower roof portion in the roof structure of FIG.

5 is a perspective view of a panel forming the lower roof portion shown in FIG. 4. FIG.

FIG. 6 is a plan view of FIG. 5;

7 is a cross-sectional view taken along the line AA of FIG.

8 is a cross-sectional view taken along the line BB of FIG.

FIG. 9 is a sectional view of a roof constructed by the construction method of the present invention.

[Explanation of symbols]

10 Underground tank 12 Side wall 14 Bottom plate 16 Roof 18 Lower roof part 20 Upper roof part 22 Precast concrete panel 22a Base part 22b-22e 1st-4th convex part 22f Steel plate 22g Bolt box 22h Through hole (for bolt) 22i connection Box 22j Insertion hole (for prestressed steel material) 22k Sheath tube 28 Supporting work 32 Lifting device (jack)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Hino 2-3 Kandajimachi, Chiyoda-ku, Tokyo Obayashi Corporation Tokyo Head Office

Claims (1)

[Claims] 1. A method for constructing a roof in which a dome-shaped roof is erected on an upper end side of a cylindrical side wall portion, wherein the roof includes two-layer lower and upper roof portions that are integrally formed, The roof portion is composed of a large number of precast concrete panels obtained by dividing the dome-shaped roof into segments, and constructs an annular support structure that supports the lower roof portion inside the side wall, and the constructed The supporting work is pulled up to be supported on the upper end side of the side wall, the panels are arranged circumferentially and in the radial direction on the upper surface side of the supporting work, and the adjacent panels arranged in the radial direction are interconnected. In this state, a prestressing force is introduced between the panels that are adjacently arranged along the circumferential direction, and after that, the precast concrete panel is used as a formwork, and concrete is placed on the upper side of the formwork. , How to build a roof and forming the upper roof part.