JPH02136455A - Floor structure - Google Patents

Abstract

PURPOSE:To increase suspension strength of a floor slab by determining, in accordance with the concrete covering depth from the underside of the floor slab at its center, the installation height of a prestressing steel at the end of the floor slab, bonded to a structural material, with a measurement made from the surface of the floor slab. CONSTITUTION:Installation height (h) of a prestressing steel 11 at the end of a floor slab 4 is determined being measured from the surface 4a of the floor slab 4 according to the concrete covering depth from the underside 4c of the floor slab. To the side of an extending part of a structural material 10 that is bonded to the floor slab 4 at an overlapping part 10a, a rising end part 10b, rising higher than the surface 4a of the floor slab 4, is provided. Then, a setting and tensioning end 12 for the prestressing steel 11 is provided at the rising end part 10b. Utilizing the setting end tensioning end 12 for the prestressing steel 11, prestressing is applied to the floor slab 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a floor structure suitable for use when introducing prestress into a floor slab.

(Prior art) When introducing prestress into the floor slab of a tube structure building, the PC flat slab of the tube structure building is designed to increase the lifting force of the floor slab by ensuring sufficient rise of the prestressed steel material. "Construction Method" (Unexamined Japanese Patent Publication 1986-
238843) has been proposed. In this proposal, the PC strand for introducing the boss tension is
Wires are placed between two pillars facing each other across the flat slab, and placed close to the bottom surface of the PC flat slab with a specified concrete cover thickness in the center of the slab, and a specified concrete cover thickness near both ends of the slab. The fixed end is placed near the top surface of the PC flat slab to form an upwardly concave shape within the PC flat slab as a whole, with both ends passing through the two pillars in the horizontal direction, and a fixed end at the outside of each of the two pillars. It is set in place, and the boss tension is introduced from the tensioned end.

(Problem to be Solved by the Invention) However, in the above proposal, it is necessary to ensure a one-to-one correspondence between the wiring position of the PC strand and the column position.
The degree of freedom in the wiring layout of the C strand is limited, and the fixed end and tension end installation locations or number of PC strands required to secure the number of PC strand wires necessary to sufficiently lift the entire flat slab are limited. It is considered difficult to secure.

(Means for Solving the Problems) The present invention involves sandwiching a floor slab on which prestress is installed and prestressed from both sides in the introduction direction, and joining structural members forming a balcony, a hallway, etc. A fixed end and a tension end of the PC steel material are formed at the rising end formed on the structural material, and the height of the PC steel material at the end of the floor slab to be joined to the structural material is determined from the top surface of the floor slab to the center of the floor slab. It is defined as the depth of cover from the bottom surface of the floor slab.

(Function) To describe the function of the present invention, the height of the PC steel material at the end of the floor slab is set from the top surface of the floor slab to the depth of cover from the bottom surface of the floor slab at the center of the floor slab.
It is possible to increase the lifting force of the floor slab by ensuring a sufficient rise within the floor slab made of prestressed steel. In particular, the fixed end and tension end of the prestressed steel material used to introduce prestress into the floor slab are made of continuous structural material that spans the entire perimeter of structures such as balconies or hallways, making it possible to freely arrange the prestressed steel material. Not only can the layout be realized, but also a sufficient number of PC steel members necessary for lifting the floor slab can be secured.

(Example) Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 3 shows a building 1 with a double tube structure. This double tube structure is a high-rise building constructed by connecting an outer tube 2 and an inner tube 3 with floor slabs 4 on each floor and assembling them three-dimensionally. Build object 1, each inner and outer tube 2
．． 3 is composed of columns 5 arranged with a predetermined span and beams 6 connecting these columns 5. Particularly, balconies 7 and corridors 8 of each floor extend over the entire circumference of the building 1 outside the outer tube 2 and inside the inner tube 3. Moreover, the inner side of the inner tube 3 is an open-air hole 9.

22. Prestress is introduced into the floor slab 4 using the following structure. In Figure 1, the outer tube 2
The part of the balcony 7 that extends outside is shown, and the structural material 10 that forms this balcony 7 has an overlapping part 10a that overlaps the floor slab 4 in the vertical direction.
C, and is entirely precast. Although not shown, the structural members forming the hallway 8 are also formed in a similar structure for the portion of the hallway 8 that extends inside the inner tube 3. The structural members 10 that form the balconies 7 or corridors 8, etc., which are continuous over the entire area around the building 1, are connected to the floor slabs 4 on which the prestressed PC steel members 11 are installed and on which the prestress is introduced, on both sides of the introduction direction. It is configured to be joined by being sandwiched between the two. in particular,
It is arranged to sandwich the floor slab 4 from both sides in the width direction.

Particularly, on the projecting side of the structural member 10 extending in the horizontal direction, a rising end 10b is formed which is higher than the upper surface 4a of the floor slab 4.
A fixed end and a tensioned end 12 of the PC steel material 11 are formed at. Specifically, the structural material 10 forming the hallway 8 has a fixed end recessed horizontally in the rising end 10b facing the atrium 9, and the structural material 10 forming the balcony 7 has an external A tension end 12 is formed by recessing in the horizontal direction on the rising end 10b facing the space, and these fixed ends and tension ends 12 are used for ηJ to introduce prestress by pre-tensioning or post-tensioning. It has become.

In addition, a PC steel material 11 extending from the floor slab 4 is inserted through the structural material 10 to form a rising end 10.
A sheath 13 is provided for leading to the fixed or tensioned end 12 of b. In this embodiment, these sheaths 13 are arranged substantially horizontally from the joint where the PC steel material 11 is inserted from the floor slab 4 into the structural member 10 toward the fixed end and tension end 12. In the illustrated structure, the joint portion is a diagonally downwardly directed inclined surface 10c of the structural member 10 that becomes the balcony 7 or the hallway 8, and both end surfaces 4b of the floor slab 4 that are abutted against the inclined surface 10c. And especially the four ends of the floor slab (
The arrangement height h of the PC steel material 11 (inner upper part of the beam 14) is the covering depth equivalent to the covering depth of the PC steel material 11 at the center of the floor slab 4 from the lower surface 4C of the floor slab.
It is set so that it can be obtained from the upper surface 4a of. Note that a spacer 16 is installed at the end of the floor slab 4 where the PC steel material 11 is placed in order to ensure a minimum cover thickness.

Furthermore, if the distance from the upper surface 4a of the floor slab 4 to the position of the prestressing steel material 11 of the tension end 12 is h', and h'-h can be set as large as possible, the lifting force will also act on the balcony (cantilevered slab). , withstand heavy loads.

It goes without saying that the structure described above is applied to the hallway 8 side as well as the balcony 7 side.

As explained above, the arrangement height h of the PC steel material 11 at the end of the floor slab 4 is set from the top surface 4a of the floor slab 4 at the depth of cover from the bottom surface 4C of the floor slab 4 at the center of the floor slab 4, so the PC A sufficient rise of the steel material 11 within the floor slab 4 can be ensured, and the lifting force of the floor slab 4 can be increased. Therefore, even in the case of a cantilevered floor slab that carries a large construction load, there is less worry about cracks occurring, and deflection due to creep or the like can be suppressed.

In particular, the PC for introducing prestress into the floor slab 4
A structural member 10 in which a fixed end and a tension end 12 of a steel member 11 are continuous over the entire periphery of a building 1 such as a balcony 7 or a hallway 8.
Since it is formed, a free layout of the PC steel materials 11 can be realized, and a sufficient number of PC steel materials 11 necessary for lifting the floor slab 4 can be secured.

Moreover, the fixed end and tension end 1 of the floor structure configured in this way
Regarding the process 2, as shown in FIG.
Since the structure is such that the decorative plate 15 is applied, there is no need to place post-filled concrete at these ends, and therefore, there is no need to worry about shrinkage of the post-filled concrete, and the water stop is also good. Rust of the steel material 11 is also suppressed.

(Effects of the Invention) In summary, according to the present invention, the following excellent effects are achieved.

(1) The placement height of the prestressed steel material at the end of the floor slab was set from the top surface of the floor slab at the depth of cover from the bottom surface of the floor slab at the center of the floor slab, so that the rise of the prestressed steel material within the floor slab was set sufficiently. It is possible to increase the lifting force of the floor slab.

(2) The fixed end and tension end of the prestressed steel material for introducing prestress into the floor slab are formed into a continuous structural member that spans the entire perimeter of structures such as balconies or hallways, so the prestressing
It is possible to realize a free layout of steel materials, and to ensure that a sufficient number of PC steel materials necessary for lifting a floor slab are provided.

[Brief explanation of the drawing]

Fig. 1 is a partial sectional view of a floor structure on the balcony side showing a preferred embodiment of the present invention, Fig. 2 is an enlarged sectional view of main parts showing processing of fixed ends and tension ends, and Fig. 3 is a double tube structure. It is a plan view of a building. 4... Floor slab 10... Structural material 10b...
Rising end 12... tension end 11... PC steel material

Claims (1)

[Claims] A structural member forming a balcony or a hallway, etc. is joined by sandwiching the floor slab on which the prestress is installed and prestress is introduced from both sides in the introduction direction, and the above-mentioned PC steel material is attached to the rising edge formed on the structural member. PC of the end of the floor slab that forms a fixed end and a tension end of the floor slab and is joined to the structural member.
A floor structure characterized in that the arrangement height of the steel material is set from the upper surface of the floor slab to the covering depth from the lower surface of the floor slab at the center of the floor slab.