JPH0721196B2 - Reverse construction method of underground structure - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for reverse driving of an underground structure in which a cast-in-place reinforced concrete pile placed in the ground is used as it is as a pillar foundation for reverse driving.

[Prior Art] As shown in FIG. 8, the conventional construction method for inversion of an underground structure of a building is to construct a steel frame column 4 having a beam joint 3 in a drilled hole 2 in a ground 1, After pouring concrete into the lower hole to form the pillar foundation 5, the hole 2 above the pillar foundation 5 is once backfilled, and then root cutting is performed as shown in FIG. The steel frame beam 6 is erected, and further the basement floor is cut and the beam is erected in order to complete the underground structure.

[Problems to be solved by the invention]

In the above-mentioned conventional method, since the process of constructing a steel column and the process of backfilling a hole are required, the work of the column foundation takes time and the work efficiency does not increase, and it is difficult to apply it to the column foundation of reinforced concrete. There was a point.

The present invention has been conceived in view of the above circumstances, and an object thereof is to provide a new construction method capable of omitting the backfilling step and improving the work efficiency of the column foundation.

[Means for solving problems]

This invention according to the above-mentioned object is for drilling holes in the ground,
After constructing a reinforced cage with a beam erection member such as a steel pipe or steel plate winding around the part corresponding to the beam joint on the first floor and basement floor, concrete is placed in the drilled hole up to the beam joint on the first floor Then, a cast-in-place reinforced concrete pile is created, and the cast-in-place reinforced concrete pile is used as a column foundation and a subterranean column for upsetting to invert the underground structure, thereby solving the conventional problems.

The present invention will be described more specifically below with reference to the illustrated example.

〔Example〕

Fig. 1 A reinforcing bar cage 13 is erected from the bottom of the hole to the top of the drilled hole in the drilled hole 12 of the required depth, which has been excavated in the ground 11 and into which the stabilizing solution has been injected. This rebar cage 13 is provided with beam erection members 14 with reinforcing ribs such as steel pipes or steel plate windings around the portions corresponding to the beam joints on the first floor 1F and basement floors B ₁ , B ₂ etc. A styrofoam 15 is provided on the outer surface of the beam erection member 14 and the floor attachment portion of the lowest floor foundation beam as a concrete fogging prevention material.

Fig. 2 Next, after removing the slime at the bottom of the hole, insert a tremie pipe (for concrete pouring) into the rebar cage 13 and concrete from the bottom of the hole to the underside of the beam erection member 14 on the first floor 1F. 16
The cast-in-place concrete pile 17 is constructed.

Fig. 3 After placing cast-in-place concrete piles 17 at the foundation of each pillar of the building, first underground cutting is performed to expose the beam joints on the 1st floor of the first floor, and steel beams 18 are erected. This erection is performed by attaching a temporary support plate 19 to the beam erection member 14 and bolting or welding a steel beam 18 to the temporary support plate 19.

After mounting the steel beam 18, the slab and the reinforcing bar 22 of the beam are arranged, and the concrete construction of the beam joint and the slab 23 is performed.

Further, as shown in FIG. 6, an anchor plate receiving iron plate 20 is attached to the beam erection member 14 by inserting it into the reinforcing bar 13a, and on the anchor plate receiving plate 20, the ground floor steel column 21
Are connected by bolting.

Fig. 4 If the 1st floor 1F concrete construction is completed, the 1st basement floor
Underground secondary root cutting to the bottom of the beam joint of B ₁ . Next, the styrofoam 15 is removed to expose the beam erection member 14 on the first basement floor B1, and the steel pillar 18 is attached to the beam erection member 14 with the temporary receiving plate 19 under the same process as the beam erection on the first floor 1F above. .

Performs a primary roots cut by the same process as FIG. 5 underground first floor B _1, carried out the erection and concrete construction of the underground second floor B ₂ of the steel beam 18, After you have completed your first basement B ₁ of the slab 23 In the same way, construct the intermediate floors of the basement in the same way, and then perform final root cutting to the bottom side of the foundation on the lowest floor. If the floor height is high, there will be 24 beams between them.
After performing root cutting by hanging, expose the anchor rebar except for Styrofoam 15, join the slab and beam rebar to the anchor rebar, and after completing flooring,
The reinforced concrete construction of the foundation beam and slab 25, the underground beam 26, and the pressure board 27 on the bottom floor is performed to complete the underground structure.

As a result, the cast-in-place concrete pile 17 is used as the pillar foundation 28 below the floor mounting surface and is used as the basement pillar 29 above.

〔The invention's effect〕

As described above, since the present invention utilizes cast-in-place reinforced concrete piles as it is as a column foundation for reverse driving, it is necessary to backfill the hole and the steel frame when the steel frame column is built into the hole to form the column foundation. The erection process can be omitted, and the time required for the pillar foundation work will be shorter than in the conventional method.

In addition, since there is no need to carry in earth and sand for backfilling, and the construction of cast-in-place concrete piles and root cutting can be done smoothly, the period of underground skeleton construction is significantly shortened and the construction cost is also reduced.

[Brief description of drawings]

FIGS. 1 to 7 show an embodiment of a reverse construction method for an underground skeleton according to the present invention. FIGS. 1 to 5 are process explanatory drawings, and FIG. 6 is the first floor in FIG. FIG. 7 is a perspective view of a beam joint portion, FIG. 7 is an explanatory view of bar arrangement of an underground beam attachment portion, and FIGS. 8 and 9 are explanatory views of a conventional method. 11 ... Ground, 12 ... Drilled hole 13 ... Reinforcing cage, 14 ... Beam construction member 15 ... Styrofoam, 16 ... Concrete 17 ... Cast-in-place concrete pile 18 ... Steel beam

Claims (1)

[Claims] 1. A rebar cage having a beam erection member provided with a steel pipe or a steel plate winding around a portion corresponding to a beam joint portion on the first floor and a basement floor is built in a drilled hole in the ground, and then the Pour concrete into the drilled hole up to the beam joint on the first floor to create cast-in-place reinforced concrete piles,
A method for reversing an underground skeleton, characterized in that an in-situ reinforced concrete pile is used as a pillar foundation and a subterranean pillar for reverse staking to complete an underground skeleton.