JPH0426527Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to a waterproof foundation slab for underground structures such as buildings having underground sections and underground storages.

[Prior art and its problems]

BACKGROUND ART Conventionally, in underground structures such as buildings having underground sections and underground storages, a method of waterproofing by installing water stop plates at concrete joints of foundation slabs, etc. has been adopted, but this method has had the following problems.

○B Cracks occurred at places other than the concrete joints, and even if the water stop plate was perfect, it was sometimes unable to perform its water stop function.

○B It was impossible to install water stop plates to all buried structures, as water could leak along them from underground structures such as steel frames.

○C There were cases where the water stop plate was unable to perform its full function due to misalignment caused by unexpected vibrations and unavoidable dirt and damage during construction.

This invention was made to solve the above-mentioned problems, and the purpose is to provide a waterproof foundation slab for underground structures that has good water-stopping properties and is inexpensive for equipment.

[Means for solving problems]

The waterproof foundation slab for an underground structure according to this invention is constructed by pouring cement-based hardening material into the bottom of the ground to form a disposable formwork, and interposing a water stop plate at the joint between adjacent disposable formworks to stop water. , prestressing force is introduced by placing unbonded prestressing steel materials in a series of multiple disposable formworks, and concrete is poured onto these disposable formworks to construct a foundation slab.

〔Example〕

This invention will be explained in detail below based on an embodiment shown in the drawings.

In the figure, 1 is the bottom of the underground space,
Cement-based hardening material 2 is placed on top of this in multiple steps to form a sacrificial formwork 3. Mortar, concrete, etc. can be used as the cement hardening material 2.

A water stop plate 4 is installed at the joint between adjacent disposable formworks 3 and 3.
intervene. The water stop plate 4 can be made of a material such as petyl rubber.

In addition, there is an unbonded PC in the continuous disposable formwork 3.
A steel material 5 is arranged, and a pre-tracing force is introduced after the cement-based hardening material 2 hardens. As the PC steel material 5, a PC steel wire, a PC steel stranded wire, etc. can be used. The ends of the PC steel material 5 are fixed by fixing fittings 6, but it is also possible to fix them by a predetermined number of disposable formworks 3, or by making the ends protrude from the upper surface of the disposable formwork 3, so that the entire cement After the hardening material 2 is hardened, it may be tensioned.

A protrusion 7 may be formed on the sacrificial formwork 3 to prevent displacement with the foundation slab 8 constructed thereon.

In addition, in the embodiment shown in the figure, the ground side part 9 of the underground space
A disposable formwork 3 is also formed, and the unbonded PC
A prestressing force is introduced by the steel material 5.

Introducing the prestress force between the sacrificial forms 3 and 3 in this way prevents the generation of tensile force in the sacrificial forms 3 and the splicing portions, thereby preventing cracks from occurring.

Furthermore, when constructing the disposable formwork 3, a vacuum pump is used to suck up excess water from the cement-based hardening material 2 to further improve watertightness, thereby promoting the development of the strength of the hardening material and shortening the construction period.

Concrete 10 on the disposable formwork 3 as above
A foundation slab, pine slab 11, is constructed by pouring concrete.

This invention has the above-mentioned configuration, but as shown in FIG. Alternatively, a waterproof sheet 13 such as a waterproof sheet 13 may be laid, and the cement-based hardening material 2 may be further placed on top of the waterproof sheet 13.
(In the case of Fig. 3, the unbonded PC steel material is placed in the lower sacrificial formwork 3.) [Effects of the invention] This invention has the above-mentioned configuration, and a water stop plate is installed at the joint of the sacrificial formwork. Since this is interposed, the water-stopping properties of the joint can be improved. In addition, since the unbonded PC steel wire is placed inside the disposable formwork, the prestressing force applies compressive force to the disposable formwork and the joints, and the tensile force generated by the weight of the concrete and the subsequent material causes the unbonded PC steel wire to be compressed. It prevents cracks from forming in the formwork and joints, and provides good water-stopping performance. The prestressing force closes gaps caused by displacement of the water stop plate or damage to the water stop plate, and does not impair water stop performance. Since water-stopping properties are improved, the installation and management of water pumps and drains becomes cheaper.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view of an embodiment of this invention.
FIG. 2 is an enlarged view of that part, and FIG. 3 is a partial sectional view of another embodiment. 1...Bottom of the ground, 2...Cement hardening material, 3
...Disposable formwork, 4...Water stop plate, 5...PC steel material,
6...Fixing metal fitting, 7...Protrusion, 8...Foundation slab, 9...Ground side, 10...Concrete, 1
1...pine slab, 12...lid material, 13...waterproof sheet.

Claims (1)

[Scope of utility model registration request] A cement-based hardening material is placed at the bottom of the ground to create a disposable formwork, a water stop plate is interposed at the joint between adjacent disposable formworks to stop water, and unbonded PC steel material is placed in a series of multiple disposable formworks. A waterproof foundation slab for an underground structure, characterized in that the foundation slab is constructed by placing a pre-stress force on the disposable formwork and pouring concrete onto the waste formwork.