JPH0347312A - Concrete sheet pile and driving of it - Google Patents

Abstract

PURPOSE:To simplify constructing process by a method in which high-pressure water is supplied into a pipe from the top side of a concrete sheet pile, and while jetting the water from the tip side of the sheet pile, the tip is contacted with the ground's surface and driven by its own weight and the advancing drive force, followed by injection of a filler into the pipe after the driving is stopped. CONSTITUTION:A concrete sheet pile 10 with PC steel wires as the main steels consists of concrete 11, main steel 12, sub-steel 13, and fabricating steel 14. In pipes 15a - 15f for conveyance of high-pressure water, the sub-steel on given places is replaced and a male screw 16 projected from the ends of each top is coupled with the female screw of the connecting metal of pipe leading to a water jet pump. High-pressure water is supplied into the pipe from the top of the sheet pile 10 and the sheet pile 10 is positioned on the ground's surface while jetting the water from the tip side pipe. The sheet pile 10 is driven by its own weight and a given advancing drive force, and after the water is supplied, a filler is packed into the pipe quickly. The construction period can thus be shortened.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method of driving concrete sheet piles using a water jet, which is used for port structures, river revetments, sewage retaining walls, etc. Regarding the concrete sheet pile used.

(Conventional technology) The soil conditions at the site for the concrete sheet piles are silt.

It is used in clay, sandy soils, or gravel, and is often driven using a water jet.

FIG. 2(a) shows a cross-sectional structure of an example of this kind of conventional concrete sheet pile, and FIG. 2(b) shows the conventional state when it is placed.

100 in the same figure (a) has a wave-shaped cross section.

This is a conventional concrete sheet pile using PC steel wire as the main steel material, 11 is concrete and 12 is the main steel material.

13 is a subphase material, and 14 is an assembly steel material. Main steel material 12 mentioned above
The number of sub-phase materials 13 to be buried and the diameter of the steel material differ depending on the type and size of the sheet pile corresponding to the required strength.

Figure (b) shows the case where a vibrohammer is used during driving, where VH is the vibrohammer and CH is the concrete sheet pile 1 fixed to the lower part of the vibrohammer VH.
00 is a chuck for gripping, and G and R are guide frames and pulling rolls that position and guide the concrete sheet pile 100 during pouring.

WJ is a water jet unit.

Therefore, the water jet unit WJ has two high-pressure pipes P that are approximately the same length as the total length of the concrete sheet pile 100.
For example, as shown in FIG. 1(a).

High-pressure water is supplied from a water jet pump (not shown) to a hose 2. Nipple 3. The water jet J is introduced into the high pressure pipe P through a joint 4 consisting of a female elbow, and is injected from a jet nozzle 5 attached to the tip of the high pressure pipe P.

The usual construction method is to first erect a pilot steel sheet pile at the location where the concrete sheet pile will be driven, and then pull it out to form a guide hole. Next, start the water jet as shown.
The concrete sheet piles 100 equipped with the units WJ are positioned so that the concave portions and convex portions of the side surfaces of adjacent concrete sheet piles 100 are fitted into each other, and the tips thereof are positioned over the openings of the guide holes. In this state, the water jet pump is driven to supply high pressure water to the high pressure pipe P, and the water jet J is injected from the jet nozzle 5, softening and removing the earth and sand around the guide hole where the concrete sheet pile is to be driven. The balls are driven sequentially into the guide hole using the weight of the tool 100 itself and the forward driving force generated by the vibration of the vibrohammer VH that has started driving.

(Problems with conventional technology) Conventional construction methods require a pre-process to form guide holes by erecting and pulling out pilot steel sheet piles before driving concrete sheet piles, and the equipment required for this increases construction costs. The process was complicated and extremely complicated.

Not only that, but the conventional water jet unit WJ
Now, multiple high-pressure pipes P are connected to 100 concrete sheet piles.
Since it is configured to hang down along the surface of the hole and spray the water jet J toward the earth and sand around the guide hole, if there is, for example, gravel or hard soil lumps in front of the jet nozzle 5 during drilling, these may When intervening between the concrete sheet pile 100 and the hanging high-pressure pipe P, the high-pressure pipe P is separated from the surface of the concrete sheet pile 100 and the direction of high-pressure water jetting is deflected, softening and eliminating earth and sand in the direction of deflection. Therefore, even if guide holes are provided, the concrete sheet piles 100 tend to sink in the direction of least resistance, and sometimes the concrete sheet piles 100 are not driven vertically. In this case, it was necessary to take measures such as lifting the concrete sheet pile 100 once and moving it back, and then bringing the high-pressure pipe P separated from the surface of the concrete sheet pile 100 back to the surface again.

In addition, although Fig. 2(b) above shows an example in which three high-pressure vibrators P are used, in reality, many more are often used, and a large number of high-pressure pipes P are used as a setup before driving. It is necessary to properly attach the pipe P along the surface of the concrete sheet pile 100, and after driving, it is necessary to pull out the high pressure pipe P from the soil as a post-process, making the on-site work complicated and lacking in workability, and improvements have been desired.

(Purpose of the Invention) The present invention has been made to solve the above-mentioned problems of the conventional concrete sheet pile driving method using a water jet and the concrete sheet piles used therein. The purpose of the present invention is to provide a concrete sheet pile driving method that makes it possible to simplify the process and simplify on-site workability while ensuring efficiency and ease, and to provide a concrete sheet pile used in the method.

(Configuration of the first invention) The configuration of the first invention of the present application is as follows: (1) The pipe material for high-pressure water conduction uses a concrete sheet pile buried and penetrated in the axial direction instead of the secondary steel material at a predetermined position in the concrete, (2) The concrete sheet pile is placed in a state where its axis is oriented in the driving direction, and high-pressure water is fed into the pipe from the top side of the concrete sheet pile of the pipe material and is injected as a jet from the pipe end on the tip side, and the tip is directly placed into the driving position. (3) Drive the concrete sheet pile toward the jet impact area using the own weight of the concrete sheet pile and a predetermined forward driving force applied to the concrete sheet pile; (4) After driving, use high-pressure water to After stopping feeding.

The concrete sheet pile driving method is characterized by quickly press-fitting a filler into the pipe material.

(Function of the first invention) While the conventional construction method injects water jet toward the earth and sand around the guide hole to soften and eliminate it, the method of the first invention of the present application injects the water jet toward the earth and sand immediately before driving the concrete sheet pile. Since it is injected to soften and eliminate the steel, pilot steel sheet piles are placed in advance at the conventional concrete sheet pile driving position.
It eliminates the need for the pre-process of pulling out and forming guide holes, it ensures that the front direction of the concrete sheet pile, which is the driving direction, exhibits low resistance to driving, so it enables straight and easy driving, and This has the effect of eliminating the need for the setup work of attaching a large number of high-pressure pipes to the surface of the concrete sheet pile before driving the concrete sheet pile, and the post-process of pulling out the high-pressure pipes from the soil after driving.

In addition, the filler that is press-fitted into the pipe material after driving not only prevents the pipe material itself from rusting, but also penetrates into the soil at the tip of the sheet pile to form roots of the concrete sheet pile, improving the strength of the structure. be.

(Structure of the second invention) Therefore, the gist of the second invention regarding the structure of the concrete sheet pile used in the construction method of the first invention is as follows: A pipe material is arranged in place of the steel material, (b) and the pipe material is penetrated through the concrete and opened at the top end surface and the tip end surface, and (C) the high pressure of the pipe material is used as a passage for high pressure water. This concrete sheet pile is characterized by being set such that expansion of the pipe diameter can be suppressed when water flows through the concrete sheet pile.

(Example) The second invention of the present application will be described in detail below according to the example shown in FIGS. 1(a) to (C).

FIG. 1(a) shows a cross section of a concrete sheet pile lO according to an embodiment of the present invention, which exhibits a corrugated shape and uses PC steel wire as the main steel material.
1 is concrete and 12 is the main steel material.

13 is a secondary steel material, and 14 is an assembly steel material. These elements are the same as before, but in the present invention, the number of secondary steel materials 13 is increased compared to FIG. 2 (a) showing the cross section of the conventional concrete sheet pile lOO. As is immediately apparent, the number of secondary steels is decreasing, and the secondary steels at predetermined positions in the group of secondary steels are replaced by hollow pipe materials shown as 15a-15f. In this case, the introduction of prestress into the concrete by the main steel material 12 is of course the same as before.

Each of the pipe materials 15a to 15f is shown in FIG. 1(b).
As shown in , a predetermined length is exposed from the concrete A at the top end of the concrete sheet pile 10, and each of the exposed portions has a predetermined length range from the end.

For example, the male threaded portion 16 is formed over a length of 20 to 30 mm, and can be screwed into the female thread of a connecting fitting located at the tip of a conduit communicating with a water jet pump. Therefore, at the site, the driving setup is completed simply by attaching the connecting fittings to each of the pipe materials 15a to 15f.

In addition, each of the pipe materials 153 to 15f is shown in FIG.
), a predetermined length is exposed from the tip end face of the concrete sheet pile 10 (concrete) B, and each exposed portion has a predetermined length range 1, for example, 20 to 30+sa from the end.
A male threaded portion 17 is formed over the +, and can be screwed into the female thread of the water jet nozzle. Therefore, if the concrete arrow 110 is manufactured with a disposable water jet nozzle installed and shipped, no work is required on site.

Furthermore, instead of forming the above-mentioned male threaded part 17 on this exposed part, the inner diameter of the pipe at the tip is formed into a tapered shape by swaging, etc., to form an opening, as shown in FIG. 1(d). It is also possible to reduce the size and use this portion as the nozzle portion 18.

As the pipe material 15, one having substantially the same cross-sectional area as the solid auxiliary steel material 13 is used.

To explain using a specific numerical example, for example, if the diameter of the secondary steel material 13 is φ13am, the outer diameter is φ17+nm.

A pipe material 15 with a wall thickness of 31III is used. If the wall thickness of the pipe material 15 is about 3II11, it can withstand the expansion force of concrete during the concrete sheet pile manufacturing process, and has sufficient resistance against high pressure water (150 kg/cm") flowing inside the pipe, and The diameter of the pipe hardly expands when water flows through it, so there is no risk of causing cracks that are harmful to concrete.

Regarding the "cover" of concrete, the outer diameter of the pipe material 15 is 4a+m larger than the outer diameter of the sub-steel material 13, but the JIS standard specifies that the concrete thickness is 100m+peng, so it is about 4mm thick. In terms of diameter difference, even if the diameters of the main steel members 12 and the assembled steel members 14 are added together, the necessary “cover” of 12 mm for the secondary steel members is sufficiently secured.

Although the number of secondary steel materials 13 and pipe materials 15 buried in the concrete differs for each concrete sheet pile IO of type 1 dimension, it is preferable that the number ratio between the two is about 1:1.

(Other Examples) In the above explanation, the case where the secondary steel materials at some predetermined positions in the secondary steel material group of concrete sheet piles that have a corrugated cross section and use PC steel wire as the main steel material are replaced with pipe materials. However,
The present invention has a different cross-sectional shape.

It goes without saying that, for example, a similar arrangement can be adopted for rectangular concrete sheet piles, and the construction can be carried out according to the above-mentioned driving method of the present invention.

In addition, as an application of the present invention, for concrete sheet piles in which ordinary ROM materials are used as the main steel materials, some of the main steel materials at predetermined positions of the main m material group are replaced with pipe materials, and then according to the driving method of the present invention. All you have to do is construct it.

In the above example, an example of using a pipe material in which the pipe diameter hardly expands when high-pressure water is passed was given. However, if the pipe material is thin and the pipe diameter expands when high-pressure water passes through, Cracks in concrete can be prevented by applying a cushioning agent that can absorb the expansion of the pipe diameter to the outer circumferential surface of the material, or by applying a cushioning agent that can absorb water pressure to the inner peripheral surface to suppress the expansion of the pipe diameter. To prevent. In this case, the cushioning agent also serves as rust prevention for the pipe material.

(Effects of the invention) The present invention eliminates the need for the pre-process of forming guide holes by erecting and pulling out 8M sheet piles, which was required in the conventional construction method, thereby reducing equipment costs and simplifying the process. Since the water jet can be shortened and the directional light of the water jet is directed toward the front of the driving head, straight driving of concrete sheet piles becomes reliable and easy, and furthermore, it is possible to install a large number of high-pressure pipes before driving the concrete sheet piles as in the past.

Pulling out the high-pressure pipes from the soil after driving them (no post-processing is required, so on-site work efficiency is greatly improved. In addition, roots are formed in the concrete sheet piles that have been placed, increasing the strength of the structure. It has been praised in the world for its remarkable effects in many fields, such as contributing to sexual improvement.

[Brief explanation of drawings]

FIG. 1(a) is a cross-sectional view of one embodiment of the concrete sheet pile of the present invention, and FIGS. 1(b) and (C) are respectively a perspective view of the top portion and a perspective view of the tip portion of the embodiment shown in FIG. 1
Figure (d) is a partial sectional view of the tip of another embodiment, and Figure 2 (a)
and (b) is a cross-sectional view of a conventional concrete sheet pile and a perspective view showing a conventional concrete sheet pile driving state. 10.--.--Concrete sheet pile 11--.・・−・−・・−・・Top end surface B−−−−−−・−・・−・Tip end surface pipe material

Claims (1)

[Scope of Claims] 1) A concrete sheet pile is used in which the pipe material for high-pressure water conduction is buried and penetrated in the axial direction instead of the secondary steel material at a predetermined position in the concrete, and the axis of the concrete sheet pile is oriented in the driving direction. In this state, high-pressure water is fed into the pipe from the top side of the concrete sheet pile of the pipe material, and is injected as a jet from the pipe end on the tip side, while the tip is brought into direct contact with and positioned on the earth and sand surface at the driving position, and the jet impact portion is The filling material is driven into the concrete sheet pile using the own weight of the concrete sheet pile and a predetermined forward driving force applied to the concrete sheet pile, and after finishing the driving and stopping the supply of high-pressure water, the filler material is immediately press-fitted into the pipe of the pipe material. This concrete sheet pile driving method is characterized by: 2) Concrete sheet piles that are driven using water jets are constructed by placing pipe materials in place of secondary steel materials at predetermined positions in the group of secondary steel materials buried in the concrete, and by passing the pipe materials through the concrete to form the top end surface. and a concrete sheet pile, which has an opening at the tip end surface and is configured to suppress expansion of the diameter of the pipe when high-pressure water is passed through the pipe material, the inside of which is used as a passage for high-pressure water. 3) The concrete sheet pile according to claim 2, wherein the pipe material has a wall thickness that prevents expansion of the pipe diameter as much as possible when high-pressure water is passed through the pipe material. 4) The concrete sheet pile according to claim 2, wherein the outer peripheral surface or the inner peripheral surface of the pipe material is coated with a cushioning agent capable of absorbing expansion of the pipe diameter when high-pressure water is passed through the pipe material. 5) The concrete sheet pile according to claim 2, wherein a predetermined length of the pipe material is exposed from the top end surface of the concrete sheet pile, and the said portion is formed so as to be connectable to a conduit that communicates with a water jet pump. 6) The concrete sheet pile according to claim 2, wherein a predetermined length of the pipe material is exposed from the tip end face of the concrete sheet pile, and a water jet nozzle is disposed in this part. 7) The concrete sheet pile according to claim 2, wherein the pipe material is exposed for a predetermined length from the tip end face of the concrete sheet pile, and the inner diameter of the pipe at the tip is formed into a tapered shape to form a nozzle portion.