JP2000045272A - Reinforcement concrete pile and its driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cast-in-place high quality concrete pile consolidated and high in strength. SOLUTION: This reinforcement concrete pile is a concrete pile to be formed under a cast-in-place pile construction method. In this case, it is furnished with a reinforcement cage body 12, a concrete column body 14 in which the reinforcement cage body 12 is buried and a tubular impervious sheet cylinder body 16. A covering control member 18 projected in the radial direction of the impervious sheet cylinder body 16 from the reinforcement cage body 12 is provided in the longitudinal direction of the reinforcement cage body 12, and concrete covering on the reinforcement cage body 12 is secured by holding specified dimensions between the reinforcement cage body 12 and the impervious sheet cylinder body 16. Consequently, it is possible to prevent outflow of concrete by the impervious sheet cylinder body at the time of placing concrete and to prevent lowering of concrete strength of the reinforcement concrete pile due to outflow of cement component in concrete underground and its elution into underground water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast-in-place reinforced concrete pile and a method of placing a reinforced concrete pile, and more particularly, to a cast-in-place reinforced concrete pile having a configuration optimal for soft ground and the like, and a soft ground and the like. The present invention relates to a method of placing a reinforced concrete pile optimally when placing a reinforced concrete pile in place.

[0002]

2. Description of the Related Art The cast-in-place pile method is a type of pile foundation method in which a building on the ground is supported by a pile foundation. When a pile is formed in the ground, the pile is directly driven at the place where the pile foundation is formed. This is a method of construction in which a hole is made in the ground in some way, and concrete is poured into the hole to build a reinforced concrete pile. There are various methods for opening the hole, and there are a mechanical drilling method such as an earth drill method, a Venoto method (all casing method), a reverse method, a replacement method such as a PIP method, and the like.
For example, in the earth drilling method, first, a vertical hole is made in the ground from the surface of the ground using an earth drill machine, and then a reinforcing rod cage formed by assembling reinforcing bars in a cage shape on the ground is fed into the vertical hole. Subsequently, a concrete column is driven into the vertical hole so as to embed the reinforcing bar cage, thereby forming a reinforced concrete pile.

When excavating a vertical hole, it is necessary to prevent the collapse of the hole wall. Therefore, the collapse of the hole wall has been conventionally prevented by various methods. For example, insert a pipe-shaped steel casing tube as you dig a vertical hole, pull out the casing tube together with concrete casting, with the drilling of the hole, pour water or muddy water, apply water pressure to the hole wall, or There are a method of forming a mud film on the pore wall with fine particles of clay and silt to stabilize the pore wall, a method of injecting a chemical such as a coagulant into the ground in advance, and a method of stabilizing the ground.

Conventionally, the cast-in-place pile method has been often used in the field where the ground is relatively good, that is, there is no aquifer and hardly collapses. Due to the rapidness of construction, the cast-in-place pile method is increasingly used in soft ground areas consisting of sedimentary layers, urban areas including aquifers and confined aquifers, areas near coasts and rivers, etc. . On the other hand, with increasing awareness of the importance of seismic design and seismic construction, there has been a growing demand for the construction reliability of foundation piles for structures. In particular, the reliability of foundation piles on highways, railway overpasses, high-rise buildings, and the like has been regarded as important, and it has become increasingly important to ensure the quality of foundation piles as designed during construction.

[0005]

However, in the conventional cast-in-place pile method, when concrete is poured into a vertical hole, the cement component of the concrete diffuses from the hole wall into the ground,
It often eluted into groundwater. for that reason,
There is a problem that it is difficult to maintain the cement component as designed, and it is difficult to construct a high-quality concrete pile with high reliability and high density. Therefore, an object of the present invention is to provide a high-quality concrete pile having high strength and high reliability as a reinforced concrete pile by a cast-in-place pile method. An object of the present invention is to provide a method of building with high reliability by a cast-in-place method.

[0006]

Means for Solving the Problems To achieve the above object, a reinforced concrete pile according to the present invention by a cast-in-place pile method comprises inserting a reinforced basket into a vertical hole opened on the ground surface,
Next, in a cast-in-place reinforced concrete pile in which concrete is fed into a vertical hole so as to embed the reinforcing rod cage, a water-impermeable sheet cylinder formed by forming a water-impermeable sheet into a tubular shape is a reinforcing rod cage. It is characterized by covering the outside of a concrete column with embedded.

[0007] As in the prior art, the reinforced cage is formed based on a reinforcing bar design of the reinforced concrete pile. The material, composition and thickness of the water-impermeable sheet are not limited as long as the water-impermeable sheet is impermeable, and may be a soft and flexible plastic sheet, a hard and rigid plastic sheet, or a thin metal plate. Further, the water-impermeable sheet cylinder does not need to be provided over the entire length of the reinforced cage, and, for example, the water-impermeable sheet cylinder is only provided at a portion where the reinforced concrete pile contacts the soft ground, the aquifer or the pressurized water layer. It may be provided. The present invention is applicable to all types of reinforced concrete piles formed by the cast-in-place pile method.

[0008] In order to secure the concrete covering of the reinforcing bar cage, a covering control member is provided between the reinforcing bar cage and the water-impermeable sheet cylinder so that the reinforcing bar can be interposed between the reinforcing basket and the water-impermeable sheet cylinder. Maintain the dimensions of The structure and type of the cover control member are arbitrary as long as the dimensions between the reinforcing rod cage and the water-impermeable sheet cylinder can be maintained. Preferably, the covering control member projecting radially from the reinforcing rod cage toward the water-impermeable sheet cylinder and maintaining a predetermined dimension between the reinforcing rod cage and the water-impermeable sheet cylindrical body is at least a reinforcing rod cage. Provided in the longitudinal direction of the body, a water-impermeable sheet cylinder is fixed to the outer edge of the cover control member. The number of covering control members is arbitrary, so that the impermeable sheet cylinder is fixed so that the concrete covering can be maintained. Thereby, the cover control member can also be used as a fixing member for the impermeable sheet cylinder.

In the method of placing a reinforced concrete pile according to the present invention, a reinforced concrete cage is inserted into a vertical hole opened on the surface of the ground, and then concrete is fed into the vertical hole so as to embed the reinforced cage and the concrete is cast. In the method of placing a reinforced concrete pile, the outside of the reinforced cage is surrounded by an impermeable sheet cylinder when the reinforced cage is inserted into the vertical hole opened on the ground surface. If necessary, a conventional method is applied to the hole wall to prevent the hole wall from collapsing.

There is no restriction on the method of surrounding the outside of the reinforcing rod cage with the water-impermeable sheet cylinder. For example, at least the covering control member projecting from the reinforcing rod cage in the outer radial direction by a predetermined dimension is provided. A step of providing in the longitudinal direction, surrounding the outside of the rebar cage with an impermeable sheet, covering both ends of the impermeable sheet and fixing the outer edge of the control member to form an impermeable sheet cylinder, A step of covering the body with a water-impermeable sheet cylinder, and then inserting a reinforced basket into a vertical hole, casting concrete inside the water-impermeable sheet cylinder and embedding a reinforced basket to form a reinforced concrete pile And a process. The method of fixing both ends of the water-impermeable sheet to the outer edge of the control member is not limited, and includes, for example, a fixing method using an adhesive using an adhesive and a mechanical fixing method using a pin or the like.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. Embodiment of cast-in-place reinforced concrete pile This embodiment is an example of an embodiment of a reinforced concrete pile according to the present invention, and FIG. 1A is a cross-sectional view of the reinforced concrete pile of this embodiment, and FIG. b) is a perspective view of a reinforced concrete pile according to the embodiment, and FIG. 2 is a detailed view of a covering control member. The reinforced concrete pile 10 of this embodiment is a reinforced concrete pile formed by a cast-in-place pile method, and as shown in FIG.
It has a concrete pillar 14 in which a reinforcing rod body 12 is embedded, and a tubular water-impermeable sheet cylinder 16 surrounding the outside of the concrete pillar 14.

Two cover control members 18 are provided in the longitudinal direction of the reinforcing rod cage 12 and project in the radial direction from the reinforcing rod basket 12 toward the cylindrical water-impermeable sheet cylindrical body 16. The concrete covering the reinforcing bar cage 12 is ensured while maintaining a predetermined dimension between the reinforced basket 12 and the water-impermeable sheet cylinder 16. In other words, the projecting length of the covering control member 18 is the size of the concrete covering of the reinforcing bar cage 12. In the embodiment, as shown in FIG. 2, as the covering control member 18, trapezoidal angle steels 18 A, B having the same height as the required covering dimension of the concrete are provided on the outside of the rebar cage body 12 in the longitudinal direction. Are welded along. Instead of the unequal angle iron, a steel material such as a T-beam may be used.

The water-impermeable sheet cylinder 16 is formed by winding a single impermeable sheet into a tube, and fixing both ends 16A and 16B at the outer edge of the covering control member 18 as shown in FIG. ,
A pin or stud 2 is inserted through a stop plate 20 made of another thin iron plate.
Fixed at 2. In the present embodiment, the water-impermeable sheet forming the water-impermeable sheet cylindrical body 16 has a thickness of 0.5 mm to 2.0 mm, which is commercially available as a water-impermeable sheet for civil engineering.
Vulcanized rubber sheet or soft vinyl chloride sheet. As the vulcanized rubber-based sheet, for example, those sold under the trade name "Geoliner" by Bridgestone Corporation can be used, and the soft vinyl chloride sheet can be sold under the trade name "Vinica Sheet" from Mitsubishi Chemical MKV Co., Ltd. You can use what is.

Reinforced concrete pile by cast-in-place pile method
Example embodiment of the punching設方method With reference to FIGS. 3-5, illustrating a punching設方method reinforced concrete piles 10. FIG. 3 to FIG. 5 are explanatory diagrams for each step when the reinforced concrete pile is driven by the cast-in-place pile method. FIG. 3A is a cross-sectional view,
FIG. 3B is a perspective view. The same applies to FIGS. 4 and 5. First, as shown in FIGS. 3A and 3B,
Based on the rebar diagram, using a large number of rebars,
Assemble. Next, as shown in FIGS. 4A and 4B, a long cover control member 18 extending in the longitudinal direction of the reinforcing bar cage 12 is welded at two opposing positions of the reinforcing bar cage 12. The welding is not limited to two places, but may be performed at several places as needed. Next, a water-impermeable sheet is wound around the outside of the reinforcing rod basket 12, and as shown in FIG. Is arranged and fixed with the pin 22, and the water-impermeable sheet cylinder 16 is formed outside the reinforcing rod cage 12 as shown in FIGS. 5A and 5B. Then
In the same way as before, a reinforced cage 1
2 is inserted and concrete is cast inside the water-impermeable sheet cylinder 16 to form a cast-in-place reinforced concrete pile 10.

The water-impermeable sheet cylindrical body 16 is
It is not necessary to provide the water-impermeable sheet cylinder 16 only on the portion in contact with the soft ground, the aquifer layer or the pressurized water layer, as shown in FIG. 6, for example.

[0016] The reinforced concrete pile 10 according to the embodiment of the present invention.
Specifically, for example, as shown in FIG.
29mm diameter rebar and hoop bar 12B
A reinforcing bar cage 800 having an outer diameter of 800 mm assembled from a different reinforcing bar having a diameter of 19 mm, a flap controlling member 18 made of an unequal side angle steel having a height of 125 mm to secure a flap of about 100 mm, and a thickness of 1.0 mm impermeable sheet cylinder 16
A reinforced concrete pile having an outer diameter of 1000 mm, comprising a 1.6 mm-thick stop plate 20 and a concrete column 14 which is cast inside the water-impermeable sheet cylinder 16 and has a reinforced cage 12 embedded therein. is there.

[0017]

According to the present invention, there is provided a cast-in-place reinforced concrete pile in which a steel cage is formed in a vertical hole opened on the surface of the ground, and concrete is then fed into the vertical hole so as to embed the steel cage. The structure of the cylindrical impervious sheet cylinder covers the outside of the concrete column in which the reinforcing bar cage is embedded, so that concrete can be prevented from flowing out of the impervious sheet cylinder during concrete placement. This prevents the concrete component of the reinforced concrete pile from decreasing due to the cement component in the concrete flowing out into the ground or dissolving in the groundwater.

[Brief description of the drawings]

FIG. 1A is a cross-sectional view of a reinforced concrete pile according to an embodiment, and FIG. 1B is a perspective view of the reinforced concrete pile according to the embodiment.

FIG. 2 is a detailed view of a cover control member.

FIG. 3 is an explanatory view for each step when driving a reinforced concrete pile by a cast-in-place pile method.

FIG. 4 is an explanatory view subsequent to FIG. 3 for each step when driving a reinforced concrete pile by a cast-in-place pile method.

FIG. 5 is an explanatory view subsequent to FIG. 4 for each step when driving a reinforced concrete pile by the cast-in-place pile method.

FIG. 6 is a perspective view illustrating an arrangement of a water-impermeable sheet cylinder.

FIG. 7 is a cross-sectional view of a specific example of a reinforced concrete pile.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Reinforced concrete pile of embodiment example 12 Reinforced cage 14 Concrete column 16 Impermeable sheet cylinder 18 Cover control member 20 Stop plate 22 Pin or tack

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Sakae Ushijima 36-1 Tsukuba, Ibaraki Pref. Aoki Construction Research Laboratory F-term (reference) 2D041 AA01 DA03

Claims (5)

[Claims] An impervious sheet in a cast-in-place reinforced concrete pile in which a steel cage is inserted into a vertical hole opened on the surface of the ground, and then concrete is fed into the vertical hole so as to embed the steel cage and cast. A reinforced concrete pile, characterized in that a water-impermeable sheet cylindrical body formed of a cylindrical shape covers the outside of a concrete column in which a reinforced cage is embedded. 2. A covering control member which projects radially from a reinforcing bar cage toward an impermeable sheet cylinder to maintain a predetermined dimension between the reinforcing bar cage and the water-impermeable sheet cylinder, at least a reinforcing bar. 2. The reinforced concrete pile according to claim 1, wherein the reinforced concrete pile is provided in a longitudinal direction of the cage body, and the impermeable sheet cylinder is fixed to an outer edge of the covering control member. 3. 3. A cast-in-place reinforced concrete pile driving method in which a reinforcing steel cage is inserted into a vertical hole opened on the ground surface, and then concrete is fed into the vertical hole so as to embed the reinforcing steel cage body. In inserting the reinforced cage into the vertical hole opened in
A method for placing a reinforced concrete pile, characterized in that the outside of a reinforced cage is surrounded by an impermeable sheet cylinder. 4. A step of providing, at least in the longitudinal direction of the reinforced cage body, a cover control member projecting outwardly in a predetermined direction from the reinforced cage body in a radial direction, and surrounding the outside of the reinforced cage body with a water-impermeable sheet. Forming the water-impermeable sheet cylinder by covering both ends of the impermeable sheet with the outer edge of the control member, and covering the reinforcing rod cage with the water-impermeable sheet cylinder, and then inserting the reinforcing rod cage into the vertical hole Then, cast concrete inside the water-impermeable sheet cylinder and embed a steel cage,
4. A method for placing a reinforced concrete pile according to claim 3, further comprising the step of forming a reinforced concrete pile. 5. When placing a reinforced concrete pile by a cast-in-place pile method in a vertical hole penetrating any of the soft ground, the aquifer layer and the confined water layer, The method of placing a reinforced concrete pile according to claim 3 or 4, wherein the penetrating portion of the reinforced cage body is covered with a water-impermeable sheet cylinder.