JP2023003792A - Back filling structure - Google Patents

Abstract

To suppress slippage of a drilling bit when drilling a bottom portion of an existing skeleton that is back-filled.SOLUTION: A back filling structure 10 includes an existing skeleton 50 that is back-filled, and a hole 100 formed at a drilling part 90 to be drilled with a drilling bit 74 at a base plate 52 of the existing skeleton 50.SELECTED DRAWING: Figure 1

Description

The present invention relates to a backfill structure.

Cited Document 1 discloses a technique related to a construction method for an underground structure under the condition that the groundwater level is high and an existing underground building exists. In this prior art, a thin wall that retains only water stopping performance is built around the existing underground frame of an existing underground structure until it reaches a position deeper than the existing underground frame, and the outer wall of the existing underground frame is used as a retaining wall. and excavation necessary for new construction.

Patent Document 2 discloses a technique related to a guide instrument. In this prior art, the guide device is a stirring rod that constitutes a soil improvement forming device that forms a soil improvement body for improving the ground, and is a guide device for guiding the stirring rod that stirs the soil of the ground. and a tubular vibration suppressing portion formed so that the stirring rod can be inserted therethrough, the vibration suppressing portion for suppressing horizontal vibration of the stirring rod inserted through the vibration suppressing portion.

Japanese Patent Application Laid-Open No. 2001-271365 JP 2021-38553 A

When drilling the bottom of a backfilled existing structure, if the rigidity of the drilling bit is smaller than the reaction force acting during drilling or if the drilling part is on an inclined part, the drilling bit will slip, resulting in a construction error. It is likely to grow.

SUMMARY OF THE INVENTION In view of the above facts, it is an object of the present invention to suppress the slippage of a drill bit when drilling the bottom of a backfilled existing structural body.

A first aspect is a backfilling structure comprising a backfilled existing skeleton and a recess with a bottom provided at a drilling portion drilled with a drilling bit at the bottom of the existing skeleton.

In the backfilling structure of the first aspect, a recess with a bottom is formed in a drilled portion drilled with a drill bit in the bottom of the existing frame. Therefore, when drilling the bottom of the backfilled existing building frame, the drilling bit hits the side wall of the recess formed in the drilling site, and the slippage of the drilling bit is suppressed.

A second aspect is the refilling structure according to the first aspect, wherein the recess is a hole or groove formed in the drilled portion of the bottom.

In the refilling structure of the second aspect, by forming a bottomed hole or groove in the drilled portion of the bottom, a recess is easily formed in the drilled portion.

A third aspect is the refilling structure according to the first aspect, wherein the recess is composed of an inclined portion of the bottom portion and a wall constructed at the drilled portion of the inclined portion.

In the backfilling structure of the third aspect, a wall is constructed at the drilled portion of the inclined portion, and the concave portion is formed by the inclined portion and the wall. Therefore, even if the hole is to be drilled on an inclined portion, the drill bit contacts the wall and the drill bit is prevented from slipping.

ADVANTAGE OF THE INVENTION According to this invention, the slippage of a drilling bit when drilling the bottom part of the backfilled existing structural body can be suppressed.

It is a cross section of the refilling structure of the first embodiment. (A) is a cross-sectional view of the state immediately before the drilling bit reaches the hole of the drilling portion of the backfilling structure of the first embodiment, and (B) is a cross-sectional view of the drilling bit penetrating the bottom and drilling the ground; It is a cross-sectional view of a holed state. (A) is a cross-sectional view of the state immediately before the drilling bit reaches the recessed portion of the hole drilling portion of the refilling structure of the second embodiment, and (B) is a cross-sectional view of the drilling bit penetrating the bottom and drilling the ground; It is a cross-sectional view of a holed state. (A) is a perspective view of a hole in the refilling structure of the first embodiment, and (B) is a perspective view of a groove of a modified example. It is a perspective view of the inclination part and wall of the refilling structure of 2nd embodiment.

<First Embodiment>
A backfilling structure of the first embodiment will be described.

[Overall structure]
The overall structure of the backfilling structure of this embodiment will be described.

As shown in FIG. 1, the backfilling structure 10 includes a backfilled existing skeleton 50 and a hole 100 (FIG. See also) and

The existing skeleton 50 is an underground portion of an existing building (not shown) after the above-ground portion on the ground G has been dismantled and removed. This existing frame 50 is backfilled with a backfilling material such as dismantled debris and soil. The backfilled portion is referred to as a backfilling portion 60 . Moreover, although the existing skeleton 50 of the present embodiment is made of reinforced concrete, it is not limited to this.

As shown in FIGS. 1, 2(A), 2(B) and 4(A), a bottomed hole 100 formed by excavating the bottom plate 52 is provided in the drilled portion 90 of the bottom plate 52. It is A drilling line 92 shown in FIGS. 2(A) and 2(B) is a design center line for drilling by a drilling machine 70 described later, and the drilling portion 90 is located on this line. .

As shown in FIG. 4A, the hole 100 of this embodiment has an inverted conical shape with a V-shaped vertical cross section. The side surface of the inverted conical hole 100 is an inclined surface 102 .

As shown in FIGS. 2A and 2B, a conical apex 101 at the bottom of hole 100 is formed to lie at drill line 92 .

[Action and effect]
Next, while explaining the drilling process for drilling the ground G, the operation and effect of the present embodiment will be explained.

First, as shown in FIGS. 1, 2(A), 2(B), and 4(A), an existing skeleton 50, which is an underground portion after the above-ground portion of an existing building (not shown) has been dismantled and removed, is A hole 100 is formed in the drilled portion 90 of the bottom plate 52 before backfilling with the backfilling material. At this time, the top portion 101 of the bottom of the hole 100 is formed so as to form the drilling line 92 (see FIGS. 2A and 2B).

Next, as shown in FIGS. 1, 2(A) and 2(B), the existing skeleton 50 is backfilled with a backfilling material such as dismantled debris or soil to construct a backfilling portion 60 .

Next, a drilling machine 70 (see FIG. 1) is installed on the backfilling part 60, and a drilling bit 74 provided at the tip of the rod 72 is used to drill the backfilling part 60, the bottom board 52 of the existing skeleton 50, and the bottom board. The ground G below 52 is drilled.

When the drilling bit 74 reaches the bottom plate 52 , even if the drilling bit 74 is displaced from the drilling portion 90 , the drilling bit 74 is guided toward the drilling line 92 by the inclined surface 102 on the side surface of the hole 100 .

Further, when drilling the bottom plate 52 , even if the drilling bit 74 tries to slip sideways because the rigidity of the drilling bit 74 is smaller than the reaction force acting during drilling, the sloped surface 102 of the hole 100 prevents the sideways slipping. Even if it is suppressed and skids sideways, it is again guided to the drilling line 92 side.

Therefore, the ground G below the bottom slab 52 of the backfilled existing skeleton 50 can be drilled along the drilling line 92 with high accuracy.

Here, when a through-hole is formed in the drilled portion 90 of the bottom plate 52 of the existing skeleton 50, if there is pressured water on the back surface of the existing skeleton 50, there is a risk that groundwater will blow out from the through-hole. Therefore, before forming a through-hole in the bottom slab 52, it is necessary to take groundwater treatment measures such as digging a well and pumping up the groundwater to lower the groundwater level below the existing frame 50, or creating a kiln to drain the groundwater. becomes.

On the other hand, since the hole 100 of the present embodiment has a bottom and does not penetrate through the hole, no countermeasure for underground treatment is required, which is preferable.

<Second embodiment>
A backfilling structure of the second embodiment will be described. In addition, the same code|symbol is attached|subjected to the same member as 1st embodiment, and the overlapping description is abbreviate|omitted.

[Overall structure]
The overall structure of the backfilling structure of this embodiment will be described.

As shown in FIGS. 3(A) and 3(B) , the backfilling structure 11 includes a backfilled existing frame 51 and a pedestal portion 54 as an example of a bottom portion formed on a bottom plate 53 of the existing frame 51. It is configured to have an inclined portion 55 and a wall body 210 .

The existing skeleton 51 is the underground part after the above-ground part of the existing building (not shown) has been dismantled and removed. This existing skeleton 51 is backfilled with a backfilling material such as dismantled debris and soil. The backfilled portion is referred to as a backfilling portion 61 . Moreover, although the existing skeleton 51 of the present embodiment is made of reinforced concrete, it is not limited to this.

As shown in FIGS. 3(A), 3(B) and 5, a reinforced concrete wall 210 is constructed at the drilled portion 90 of the inclined portion 55 of the pedestal portion 54 of the existing skeleton 51 . The wall 210 has an inclined surface 212 inclined on the side opposite to the inclined surface 56 of the inclined portion 55 . In this embodiment, a post-installed anchor (not shown) embedded in the inclined portion 55 is embedded in the wall 210, but the present invention is not limited to this.

The inclined portion 55 and the wall member 210 form a concave portion 200 having a V-shaped vertical cross section. The wall 210 is constructed such that the boundary position between the inclined portion 55 and the wall 210 is the drilling line 92 .

As shown in FIG. 5, a wall body having an inclined or vertical wall surface may be constructed on the side surface 202 on the front side and the side surface 203 on the back side indicated by imaginary lines (two-dot chain lines) in the recess 200. Or you don't have to build a wall. Moreover, the wall body 210 may be constructed of a steel frame material such as an L-shaped angle instead of the reinforced concrete structure.

[Action and effect]
Next, while explaining the drilling process of drilling the ground G, the action and effect of the present embodiment will be explained.

First, as shown in FIGS. 3(A), 3(B), and 5, the existing building structure 51, which is the underground portion after the ground portion of the existing building (not shown) has been dismantled and removed, is backfilled with a backfilling material. First, a wall 210 is constructed at the drilled portion 90 in the inclined portion 55 of the bottom plate 53 . At this time, the boundary position between the inclined portion 55 and the wall body 210 is formed so as to be the drilling line 92 (see FIGS. 3A and 3B).

Next, as shown in FIGS. 3(A) and 3(B), the existing skeleton 51 is backfilled with a backfilling material such as dismantled debris or soil to construct a backfilling portion 61 .

Next, a drilling machine 70 (see FIG. 1) is installed on the backfilling part 61, and a drilling bit 74 provided at the tip of the rod 72 is used to drill the backfilling part 61, the inclined part 55 of the existing skeleton 51, and the The ground G under the inclined portion 55 is drilled.

When the drilling bit 74 reaches the inclined portion 55, even if the drilling bit 74 is displaced from the drilling portion 90, the inclined surface 56 of the inclined portion 55 or the inclined surface 212 of the wall 210 allows the drilling bit 74 to drill. It is guided to the line 92 side.

Further, the wall 210 prevents the drilling bit 74 from slipping along the inclined surface 56 when drilling the inclined portion 55 .

Therefore, the ground G under the sloped portion 55 of the backfilled existing skeleton 51 can be drilled along the drilling line 92 with high accuracy.

<Others>
It should be noted that the present invention is not limited to the above embodiments.

For example, in the above-described first embodiment, the bottomed concave portion is the hole 100 having an inverted conical shape and a V-shaped vertical cross section shown in FIG. 4A, but it is not limited to this. It may be an inverted pyramid hole. Also, the recess may be a groove (elongated recess) 104 having a V-shaped cross section as shown in FIG. 4(B) instead of a hole.

Moreover, the hole 100 (FIG. 4A) or the groove 104 (FIG. 4B) formed in the bottom plate 52 is not limited to a V-shaped cross section. It may be a character shape.

Further, for example, in the second embodiment, as shown in FIG. 5, the wall surface of the wall body 210 is the inclined surface 212, but the wall surface is not limited to this, and the wall surface may be a vertical surface. .

Also, the inclined portion 55 of the second embodiment may be excavated to form the hole 100 or groove 104 as in the first embodiment.

Furthermore, a bottomed recess having a structure other than the recess 200 constituted by the hole 100 and the groove 104 of the first embodiment and the inclined portion 55 and the wall 210 of the second embodiment may be used. The point is that the vertical cross-section that has the function of preventing or suppressing the slippage of the drilling bit 74 when drilling with the drilling bit 74 should be concave such as a V-shape, an inverted trapezoid, or a U-shape.

Moreover, although the backfilled existing skeletons 50 and 51 were underground skeletons, they are not limited to this. It may be an existing backfilled skeleton built on the ground.

Furthermore, various aspects can be implemented without departing from the gist of the present invention. A plurality of embodiments and the like can be appropriately combined and implemented.

10 Backfilling structure 11 Backfilling structure 50 Existing frame 51 Existing frame 52 Bottom slab (an example of the bottom part)
54 Mounting part (an example of the bottom part)
55 inclined portion 74 drilling bit 90 drilling portion 100 hole (an example of a recess)
104 groove (an example of a concave portion)
200 recess 210 wall
G Ground

Claims (3)

The existing skeleton that was backfilled,
A bottomed recess provided in a drilling portion drilled with a drill bit at the bottom of the existing skeleton;
Backfill structure with The recess is a hole or groove formed in the drilled portion of the bottom,
The backfill structure according to claim 1. The recess is composed of an inclined portion of the bottom portion and a wall constructed at the drilled portion of the inclined portion,
The backfill structure according to claim 1.

Images