JP2000240070A - Securing method for pile head reinforcing bar insertion space in foundation pile with hollow section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a securing method for a pile head reinforcing bar insertion space in a foundation pile with a hollow section which can accurately form and secure the pile head reinforcing bar insertion space, does not require the wasteful removing work of a cement milk hardened body, and can accurately prevent a drop accident of a worker into the hollow section. SOLUTION: A mesh 2 is provided at the upper end of a foundation pile 1, a mesh 4 is provided below the mesh 2, by the height for burying pile head reinforcing bars 3, and a protective plate 5 is fitted to the upper mesh 2. After the foundation pile 1 is executed and a pit excavation is made around the pile head, the upper mesh 2 is cut, the protective plate 5 is moved onto the lower mesh 4, and the pile head reinforcing bars 3 are buried on it and connected to an upper mount structure, or an area injection doughnut body may be inflated and inserted into the upper end of the hollow section of the foundation pile 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foundation pile having a hollow portion used as a foundation for an overlying structure such as a bridge or a building structure, and more specifically, a pile head serving as a connecting portion with an overlying structure. The present invention relates to a method for securing a space for inserting a pile head reinforcement in a portion.

[0002]

[Prior art] The conventional foundation pile method has been strictly regulated because the pile driving method, which had been the mainstream until then, generates a lot of vibration and noise, and the cement milk method or the cement consolidation method is used instead. Many are adopted.
The pile has a cylindrical shape to increase rigidity, and when reinforcing piles at the end of the pile and connecting to the upper structure at the upper end of the foundation pile, a reinforcing bar is inserted inside the cavity, and the reinforcing bar is fixed with ready-mixed concrete It is often done.

However, a cavity is required at the upper end to insert a pile head reinforcing bar at the upper end of the pile, but as shown in FIG. 9, the cement paste 11 injected into the pile hole and the surrounding earth and sand rise. As it fills the cavity of the foundation pile 1, FIG.
As shown in (1), it is expensive to remove the cement paste 11 and the earth and sand. In addition, when excavation work or flooring work is performed after the pile is put into place, there is a risk that the worker may accidentally fall into the pile hole until the reinforcement for the pile head is inserted.

[0004] There have been several reports on how to deal with these problems. For example, in order to secure a space for inserting a pile head reinforcing bar at a pile head portion and to prevent a worker from falling into a cavity, a plywood plate is applied to a pile upper end as shown in FIG. Hold it down with sandbags,
The top opening of the pile cavity may be blocked until needed. However, this method may cause the sandbag to move and come off,
There are some problems with certainty.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to ensure the formation of a space for inserting a pile head reinforcing bar in a foundation pile work such as a bridge or a building, and to remove a waste cement milk hardened body. It is therefore an object of the present invention to provide a method for securing a space for inserting a pile head reinforcing bar in a foundation pile having a hollow portion, which can accurately prevent an accident of a worker falling into a hollow portion.

[0006]

Means for Solving the Problems Hereinafter, the method for securing a pile head reinforcing bar insertion space according to the first aspect of the present invention will be described with reference to the accompanying drawings. Use As shown in FIG. 1, a mesh 2 is installed at the upper end of a hollow foundation pile 1, and a mesh 4 is located at a height lower than a height for embedding a pile head reinforcing bar 3 connected to the upper structure from the mesh 2. Is installed, and a protection plate 5 is attached to the upper mesh 2 as shown in FIG.

[0007] The foundation pile 1 is driven into the pile hole excavated in the ground 6 by hitting with a hammer or the like, excavating around the pile head to expose the pile head, and cutting the upper mesh 2 to protect the pile. The plate 5 is moved onto the lower mesh 4. As shown in FIG. 3, the pile head reinforcement 3 is inserted into the cavity above the protective plate 5 and the mesh 4 and is fixed with ready-mixed concrete to be connected to the upper structure.

In the method for securing a space for inserting a pile head reinforcing bar according to the second aspect of the present invention, a known cement milk method is used as a method for constructing the foundation pile 1. As shown in FIG. 4, the foundation pile 1 having a hollow portion is inserted into a pile hole excavated in the ground 6, and cement milk is poured into the periphery to cure and harden. After excavating around the pile head, the upper mesh 2 is cut and the protection plate 5 is moved onto the lower mesh 4.
As shown in FIG. 5, the pile head reinforcement 3 is inserted thereon,
It is fixed with ready-mixed concrete and bonded to the overlying structure.

In the method for securing a space for inserting a pile head reinforcing bar according to the third aspect of the present invention, a publicly known cement milk consolidation method is used as a method for constructing a foundation pile. At the upper end of the foundation pile 1 having a hollow portion, a cylindrical doughnut for air injection made of reinforced vinyl or the like is installed at a height to embed the pile head reinforcement 3 connected to the upper structure. And FIG.
As shown in (2), the donut 7 for air injection is inflated by air injection, and is brought into close contact with the inner wall of the hollow portion. The foundation pile 1 is inserted into a pile hole excavated in the ground 6, and is buried in cement milk by rotation. In this process, excess cement milk turns into the foundation pile 1
Along the hollow portion of the donut body 7 and flows out along the hollow portion of the donut body 7 for air injection. Thereafter, the cement milk is cured and hardened. Further, after digging around the pile head, the air of the donut body 7 for air injection is evacuated, and the hardened portion of cement milk that has entered and hardened into the hollow of the donut body 7 for air injection is folded from the hardened cement milk body below it. Then, the donut 7 for air injection is removed. As shown in FIG. 8, the pile head reinforcing bar 3 is inserted into the space thus secured, and is fixed with ready-mixed concrete.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION As the meshes 2 and 4, a plurality of reinforcing bars arranged at appropriate intervals in the vertical and horizontal directions and joined to each other, a punched wire mesh, a welded wire mesh, a braided wire mesh, and the like can be appropriately adopted. The meshes 2 and 4 are installed at required locations when the foundation pile 1 is manufactured, but may be attached after the foundation pile 1 is manufactured. While the upper mesh 2 prevents the workers from falling down, the lower mesh 4 defines the bottom of the pile head reinforcing bar insertion space, and the protective plate 5 for preventing the falling of the ready-mixed concrete is made of iron plate.
It can be made of other materials. The protection plate 5 is usually attached to the mesh 2 when the foundation pile 1 is carried into the construction site.

[0011]

As described above, according to the present invention, when using the hammering method as the method of constructing the foundation pile, the meshes 2 and 4 are installed at the upper end of the hollow portion of the foundation pile 1 in the upper and lower stages, and By attaching the protection plate 5, it is possible to reliably prevent the cement paste and the earth and sand from invading to the position where the pile head reinforcement 3 is embedded. Moreover, since the hollow can be reliably closed by the protection plate 5 until the pile head reinforcement 3 is inserted, an accidental fall accident of the workers can be prevented.

When the cement milk method is used as a method of constructing the foundation pile 1, the protective plate 5 attached to the upper mesh 2 prevents cement milk from flowing into the hollow portion of the foundation pile 1 and thus hardens. Eliminates the cumbersome work of removing cement milk. In both the impact method and the cement milk method, after the upper mesh 2 is cut off, the protective plate 5 is placed on the lower mesh 4 so that the bottom of the pile head reinforcing bar insertion space is closed and the mesh 4 is removed. It is possible to accurately prevent the falling of the ready-mixed concrete from lowering.

When the dough 7 for air injection is inflated and adhered to the upper end of the hollow portion of the foundation pile 1 by using the cement milk consolidation expanding method as a construction method of the foundation pile 1, Since the upper surface opening of the doughnut body 7 for air injection is closed by the cement milk which has risen to the hollow part and hardened, the worker does not fall down. In addition, air is extracted from the donut body 7 for air injection,
By cutting off the hardened portion of cement milk in the hollow portion together with the doughnut body 7 for injecting air from the hardened cement milk below, a space for inserting a pile head reinforcing bar can be easily formed.

[Brief description of the drawings]

FIG. 1 is a plan view of a foundation pile used in an embodiment of the method of the present invention, in which a guard plate is not installed.

FIG. 2 is a vertical sectional view taken along the line AA of the foundation pile of FIG. 1 constructed by a percussion method, and a protective plate is attached to an upper mesh.

FIG. 3 is a longitudinal sectional view of the foundation pile of FIG. 1, showing a state in which a protection plate is moved onto a lower mesh and a pile head reinforcing bar is inserted.

FIG. 4 is a longitudinal sectional view of a foundation pile constructed by a cement milk method, showing a state in which an upper surface opening of the foundation pile is closed by a protection plate attached to an upper mesh.

FIG. 5 is a longitudinal sectional view of the foundation pile of FIG. 4 in a state where a protective plate is moved onto a lower mesh and a pile head reinforcing bar is inserted.

FIG. 6 is a plan view of a foundation pile constructed by the cement milk solidification method, showing a state in which a donut for air injection is inflated and mounted in a hollow portion.

FIG. 7 is a vertical sectional view taken along the line BB of FIG. 6;

8 is a longitudinal sectional view showing a state in which a dough for air injection and a hardened portion of cement milk are removed and a pile head reinforcing bar is inserted into a space secured in the foundation pile of FIG. 6;

FIG. 9 is a vertical cross-sectional view showing a state in which cement milk has entered a hollow portion from an upper surface opening of a foundation pile in a conventional method.

FIG. 10 is a longitudinal sectional view showing a state in which the hardened cement milk at the upper end of the hollow portion has been removed from the foundation pile of FIG. 9;

FIG. 11 is a longitudinal sectional view showing a state in which an upper surface opening of a foundation pile is closed with a plywood and pressed with a sandbag in a conventional method.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 foundation pile 2 mesh 3 pile head reinforcement 4 mesh 5 protective plate 6 ground 7 donut body for air injection 9 sandbag 10 veneer plate 11 cement milk 12 air port

Claims (3)

[Claims] 1. A foundation pile 1 having a hollow, a mesh 2 provided at an upper end of the foundation pile 1, and a pile head reinforcing bar 3 connected from the mesh 2 to an overlying structure are provided at a height lower than a height for embedding. And a protection plate 5 attached to the upper mesh 2. The foundation pile 1 is constructed on the ground 6 by a hammering method, and after excavating around the pile head, the upper mesh 2 is cut and protected. The board 5 is moved onto the lower mesh 4 and the pile head reinforcing bar 3 is embedded therein and connected to an overlying structure, for inserting a pile head reinforcing bar in a foundation pile having a hollow portion. How to secure space 2. A foundation pile 1 having a hollow, a mesh 2 provided at an upper end of the foundation pile 1, and a pile head reinforcing bar 3 connected from the mesh 2 to an upper structure are provided at a height lower than a height for embedding. And a protection plate 5 attached to the upper mesh 2. The foundation pile 1 is constructed in a pile hole excavated in the ground 6 by a cement milk method, and after excavating around a pile head, the upper mesh is formed. 2, the protective plate 5 is moved onto the lower mesh 4, and the pile head reinforcing bar 3 is buried on the mesh 4 and connected to the upper structure. How to secure space for insertion of pile head reinforcement 3. A cylindrical pile made of reinforced vinyl or the like which is installed at a height at which an upper end of the hollow foundation pile 1 and a pile head reinforcing bar 3 connected to an upper structure are embedded at an upper end of the foundation pile 1. The donut body 7 for air injection is expanded by air injection and brought into close contact with the inner wall of the pile hollow part, and the foundation pile 1 is inserted into the pile hole excavated on the ground 6 to remove the cement milk root. After constructing by the hardening method and excavating around the pile head, the air inside the donut body 7 for air injection is evacuated, and the hardened portion of the cement milk that has entered and hardened into the hollow of the donut body 7 for air injection is moved downward. A method for securing a space for inserting a pile head reinforcing bar in a foundation pile having a hollow portion, wherein the space is removed from the hardened cement milk body and the donut body 7 for air injection is removed.