JP2020037786A - Drilling pier - Google Patents

Abstract

To provide a drilling pier for making it possible to drill a central deep drilling portion without stopping a construction operation at a working surface and also with a high construction operation efficiency.SOLUTION: A drilling pier 1 according to the present application includes a frame-shaped pier main body 10, a fixed floor 20 spanned over an upper portion of the pier main body 10, an opening or closing floor 30 spanned over the upper portion of the pier main body 10, an opening or closing mechanism 40 attached to the pier main body 10 and capable of opening or closing the opening or closing floor 30 in the width direction of the pier main body 10 by way of jumping-up, and a ramp 50 provided at the front and rear sides of the pier main body 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an excavation pier, and more particularly to an excavation pier for deep excavation of the ground at the center of a tunnel cross section prior to invert excavation in mountain tunnel construction.

In mountain tunnel construction, a tunnel invert will be installed to suppress the displacement of the ground and secure the necessary cross section as a tunnel.
In tunnel inverting work, an invert pier that straddles the upper part of the inverting work is used to secure the traffic of construction vehicles when excavating the ground or placing concrete. Patent Literature 1 discloses a construction method of excavating an invert portion (hereinafter referred to as “invert excavation”) by sequentially shifting an invert pier to left and right side walls of a tunnel.
By the way, when there is a large amount of spring water on the back side of the lining, the ground at the center of the tunnel section is excavated in a groove deeper than the invert excavation in order to collect groundwater (hereinafter this part is called “central deep excavation”). Drainage pipes may be laid.
At this time, conventionally, (1) a method of excavating the central deep excavation portion at the face side of the invert pier and backfilling it at any time, and (2) as described in the cited document 1, moving the invert pier to one side and simultaneously excavating the invert The method of excavating the central deep part was adopted.

JP-A-6-173574

The prior art has the following problems.

<1> In the method of excavating in advance at the invert pier, since the traffic of the vehicle to the face is interrupted during the excavation, the work must be performed on a holiday when the construction of the face stops. For this reason, the progress of construction is slow and the construction period is squeezed. In addition, construction costs increase due to holiday work.
<2> In the method of pre-excavation at the invert pier, backfill is performed while laying drainage pipes from the pit side to the face side. Therefore, it is necessary to suspend the drainage pipe from the backfill soil on the wellhead side of the excavation part. Since the backfill soil has many irregularities and is likely to sink, it is difficult to balance heavy equipment and workability is poor.
<3> Deep excavation at the same time as invert excavation is difficult because the invert pier extends above the central deep excavation, and heavy equipment may interfere with the invert pier (Fig. 5). For this reason, the construction efficiency is poor and the construction period is squeezed.
<4> In either method, since deep digging is performed, the balance of heavy equipment is easily broken. In particular, in advance excavation of the invert, since work is performed on the ground where the condition is poor, workability is poor and there is a risk of falling.

  An object of the present invention is to provide a pier for excavation that can solve the above-described problems of the related art.

An excavation pier according to the present invention for solving the above-mentioned problems is provided with a pier body, a fixed floor, an opening / closing floor, an opening / closing mechanism, and a ramp.
According to this configuration, it is possible to excavate the central deep excavation while securing the passage of the construction vehicle. In addition, construction efficiency is good because excavation can be performed from a stable floor.

In the pier for excavation of the present invention, a plurality of open / close floors may be arranged in parallel in the longitudinal direction.
According to this configuration, by moving the heavy equipment while sequentially deploying the plurality of open / close floors, deep excavation over a long distance can be performed in one construction cycle.

In the pier for excavation of the present invention, the opening / closing mechanism may include a column, a traction device, and a wire.
According to this configuration, the open / close floor can be easily opened / closed with a simple structure.

In the pier for excavation of the present invention, the traction device may be a chain block and the wire may be a chain.
According to this configuration, the opening and closing floor can be opened and closed manually.

In the pier for excavation of the present invention, the pier body may be composed of two girder members and a plurality of beam members bridged over the two girder members.
According to this configuration, since the bottom of the girder material performs the function of a sled, the towing by the heavy equipment becomes easy.

With the above configuration, the excavation pier of the present invention has at least one of the following effects.
<1> The central deep excavation can be excavated without stopping the construction of the face by opening and closing the floor in accordance with the traffic of the construction vehicle. Therefore, the construction cycle is favorable, and the construction period can be significantly reduced. Since there is no holiday work, construction costs can be reduced.
<2> Excavation to a deep part, laying of drainage pipes, and backfilling can be performed from a stable floor. Therefore, workability is good and construction efficiency is high.
<3> Since the excavation precedes the invert pier, there is no interference with the pier and the excavation of the central deep excavation is easy.
<4> Since the work can be performed from a stable floor, construction safety is high.

Explanatory drawing of the pier for excavation of the present invention. Explanatory drawing of the pier for excavation of the present invention. Explanatory drawing of the usage method of the pier for excavation of this invention. Explanatory drawing of the usage method of the pier for excavation of this invention. FIG.

  Hereinafter, the excavation pier of the present invention will be described in detail with reference to the drawings.

[Drilling pier]
<1> Overall configuration (FIG. 1).
The excavation pier 1 of the present invention is a device for excavating a central deep-drain portion D for a central drainage pipe prior to invert excavation in mountain tunnel construction.
The pier 1 for excavation can be opened and closed by piercing the pier main body 10, a fixed floor 20 and an opening / closing floor 30 laid over the pier main body 10, and attached to the pier main body 10 and flipping the opening / closing floor 30 in the width direction. The opening / closing mechanism 40 and a ramp 50 provided before and after the pier main body 10 have a long rectangular shape in plan view.
The width of the pier 1 for excavation is smaller than the width of the tunnel, and wide enough to allow heavy equipment and construction vehicles to pass through the upper part.
In this example, the excavation pier 1 does not have a self-propelled function, and is moved by being towed by heavy equipment. However, the invention is not limited thereto, and a self-propelled mechanism such as a tire or a crawler may be provided.

<2> Pier body.
The pier main body 10 is a structural member of the pier 1 for excavation.
The pier main body 10 is composed of a combination of two girder members 11 arranged in parallel and a plurality of beam members 12 bridged between the two girder members 11, and forms a vertically long rectangle having the girder member 11 as a long side. Present.
Desirably, the beam material 12 is not arranged below the opening / closing floor 30, and the ground below the opening / closing floor 30 can be continuously excavated.
In this example, a section steel is used as the girder member 11 and the beam member 12.
In this example, the pier main body 10 is assembled in a configuration in which the beam member 12 rides above the girder member 11. According to this configuration, the bottom surface of the girder member 11 functions as a sled, so that the towing by the heavy equipment becomes easy.

<3> Fixed floor.
The fixed floor 20 is a work bench of the heavy equipment.
The fixed floor 20 is made of a rectangular face material. In this example, a steel lining plate is employed as the fixed floor 20.
The fixed floor 20 extends between the two girder members 11 of the pier main body 10 and is fixed to the pier main body 10.
At least one fixed floor 20 is installed at the longitudinal end of the pier body 10.
In this example, the fixed floor 20 is installed on the face side of the pier main body 10, and the fixed floor 20 shorter than the fixed floor 20 on the face side is installed on the pit side of the pier main body 10.

<4> Open / close floor.
The opening / closing floor 30 is a worktable for heavy machinery that can be opened and closed.
The opening / closing floor 30 is made of a rectangular face material. In this example, a steel lining plate is used as the opening / closing floor 30.
The opening / closing floor 30 spans between the two girder members 11 of the pier main body 10, and one side is hingedly fixed to the girder member 11, so that the opening / closing floor 30 can be flipped up and down in the width direction of the pier main body 10.
At least one opening / closing floor 30 is provided on the pier main body 10, preferably a plurality of opening / closing floors 30.
In this example, three open / close floors 30 are continuously installed between two fixed floors 20.

<5> Open / close mechanism (FIG. 2).
The opening and closing mechanism 40 is a mechanism that opens and closes the opening and closing floor 30 in the width direction.
In this example, as the opening / closing mechanism 40, a column 41 extending laterally from the girders 11 on the hinge side of the opening / closing floor 30, a traction device 42 attached to the tip of the column 41, and opening / closing of the traction device 42 and the opening / closing floor 30. A combination of wires 43 connecting the side sides is adopted.
In this example, a combination of a chain block and a chain is adopted as the traction device 42 and the wire rod 43. The chain block allows the opening and closing floor 30 to be opened and closed manually without the need for power.
In the case of the present example, it is desirable to provide a fall prevention member 44 for supporting the open / close floor 30 on the hinge side girder 11 so that the open / close floor 30 does not fall to the open side.
The configuration of the opening / closing mechanism 40 is not limited to the above, and another known configuration such as a hydraulic cylinder or a winch may be employed. The point is that the opening / closing floor 30 can be flipped up and closed in the width direction.

<6> ramp.
The ramp 50 is a passage for ascending and descending to the fixed floor 20 and the opening and closing floor 30.
The ramp 50 has a slope from the floor surface of the fixed floor 20 and the opening / closing floor 30 to the road surface.
The ramp 50 may be detachable from the pier main body 10 and may be detached when the excavation pier 1 moves.

<7> Construction method (Fig. 3).
The excavation pier 1 of the present invention is used as follows.
The pier 1 for excavation is arranged on the face side of the invert pier and at the forefront part of the construction of the central deep section D. The heavy equipment for excavation is arranged on the fixed floor 20 on the face side of the opening / closing floor 30.
By operating the traction device 42 of the opening / closing mechanism 40, the opening / closing floor 30 is opened, and the ground under the opening / closing floor 30 is exposed.
The ground under the opening / closing floor 30 is excavated from above the fixed floor 20.
When the construction vehicle passes, the open / close floor 30 is closed at one end, and the vehicle travels on the ramp 50, the fixed floor 20, and the route on the open / close floor 30.
After excavating the central deep digging part D under all the opening and closing floors 30, all the opening and closing floors 30 are closed.
Subsequently, the heavy machine is lowered to the face side of the pier 1 for excavation, and the pier 1 for excavation is pulled toward the face side by a heavy machine using a wire or the like and moves.
Since the pier 1 for excavation of the present invention can excavate from a stable floor, it is difficult to break the balance of heavy equipment even in deep excavation, and the workability is good.

<7.1> Long-distance excavation (Fig. 4).
The excavation pier 1 of the present invention enables excavation over a long distance at a time by combining a plurality of open / close floors 30.
First, only the opening / closing floor 30 on the wellhead side is opened, and the ground below it is excavated from above the central opening / closing floor 30 (a).
Subsequently, the central opening / closing floor 30 is opened, and the ground below it is excavated from the opening / closing floor 30 on the face side (b).
Finally, the opening / closing floor 30 on the face side is opened, and the ground below it is excavated from above the fixed floor 20 (c).
As described above, long-distance excavation can be performed at once by excavating while opening and closing the plurality of open / close floors 30 sequentially from the wellhead side to the face side. Thereby, the construction efficiency can be improved by extending the single movement distance of the excavation pier 1 and reducing the number of movements.
In addition, by exposing the plurality of open / close floors 30 and disposing heavy equipment for suspending the drainage pipe on the pit side of the pier 1 for excavation, the excavation of the central deep digging part D and the hanging and backfilling of the drainage pipe are performed. It can be constructed in parallel from both sides of the pier 1 for excavation.

DESCRIPTION OF SYMBOLS 1 Excavation pier 10 Pier main body 11 Girder material 12 Beam material 20 Fixed floor 30 Opening / closing floor 40 Opening / closing mechanism 41 Prop 42 Traction device 43 Wire rod 44 Fall prevention material 50 Rampway D Central deep excavation

Claims (5)

An excavation pier for deep excavation of the ground at the center of the tunnel section prior to invert excavation in mountain tunnel construction,
A frame-shaped pier body,
A fixed floor spanned over the top of the pier body,
An opening / closing floor spanned over the pier body,
An opening / closing mechanism attached to the pier main body and capable of opening and closing the openable floor in the width direction of the pier main body,
And a ramp provided before and after the pier body,
Drilling pier.   The pier for excavation according to claim 1, wherein a plurality of the open / close floors are arranged in a longitudinal direction of the pier main body.   The opening / closing mechanism includes a column protruding to the side of the pier main body, a traction device attached near a tip of the column, and a wire capable of connecting the traction device to the opening / closing floor. The pier for excavation according to claim 1 or 2.   The pier for excavation according to claim 3, wherein the traction device is a chain block, and the wire is a chain extending from the chain block to the openable floor.   The said pier main body consists of a combination of two girder members and a plurality of beam members bridging over the upper parts of the two girder members, The pier main body is characterized by the above-mentioned. Excavation pier.

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