JPS58168743A - Construction of unbond prestressed concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an unbonded prestressed concrete (hereinafter referred to as unbonded PC) construction method in which fixing portions are provided at appropriate locations on both ends of a building.

When constructing a building using the unbonded PC method, it is common practice to tension a single long piece of PC steel at 7 degrees at both ends of the building in view of the process and construction costs.

However, as sometimes reported in newspapers, there is a risk of gas explosions in apartment complexes. When the above construction method is adopted, once a gas explosion occurs and the floor, ceiling, etc. are destroyed, there is a risk that the Pc steel material will be cut.

Is this cutting caused by excessive deflection of the entire floor?
Furthermore, it may cause collapse, which is extremely dangerous.

This invention is intended to minimize the extent of sagging or destruction of the floor etc. even if an unexpected accident occurs and the paW4 material is cut.

Its gist is ``the Unhondre C method, in which anchorage points are installed at appropriate intervals between both ends of a multi-span building in which unbonded PC steel is applied to floors or beams.''

Next, explanation will be given according to the drawings.

The drawing is a plan view of a multi-span apartment building, and it is assumed that gas explosion 3 (shaded area) occurs in Figure 1. Here, since a fixing part is provided for each λ span, the area q affected by the gas explosion is limited to Nispan, and other areas outside the floor are not affected.

Figure 2 shows the fixed part Ω of the PC steel material /, and the a-a' column shows the
It is a diagram provided for each span in the bb' column for y, ko, ko, 3.3, and gespan, and in the a-c' column for each gespan.

Incidentally, as the intermediate fixing method used in this invention, the following method is used.

(c) Unbox the intermediate fixing part, expose the PaJ material after tensioning, and post-cast concrete to generate a bond.

(λ) Leave the PC steel material in the intermediate fixing part exposed, use a steel sheath fitted with a grouting pipe, take measures to prevent concrete from flowing in, and then inject grout after tensioning.

(,?) Take fixing measures at the stage of PO steel placement.

Furthermore, it is also conceivable to develop and use a dedicated fixing device suitable for each of the above methods.

Since this invention is configured as detailed above, even if an unexpected accident occurs in a certain span and concrete falls off or 10W4 material is cut, the destruction of the structure is limited to that part and other It is possible to minimize the spread of destruction and damage to the parts of the building, and the period and cost required for subsequent restoration work are extremely short.

[Brief explanation of the drawing]

The drawings are a plan view of a multi-span housing complex according to an embodiment of the present invention, and FIG. 1 is an explanatory diagram showing the range affected by a gas explosion, and FIG. 2 is an explanatory diagram showing fixing portions for each type of span. /...PC steel material U...Fixed part 3...Gas explosion occurrence point G...Node affected by gas explosion FiH 5...Area not affected by gas explosion Patent applicant
Obayashi Co., Ltd. Agent Susumu Mori

Claims (1)

[Claims] An unbonded breast-stressed concrete construction method in which anchorage sections are installed at appropriate intervals between the ends of a multi-span building in which unbonded pre-stressed concrete steel is applied to floors or beams.