JP2003328357A - Steel pipe sheet pile method - Google Patents

Abstract

(57) [Summary] [Problem] In addition to being able to prevent water pollution even in foundation work under special conditions of underwater, the workability is good, and
As a steel pipe sheet pile, the strength is increased as compared with the conventional steel pipe sheet pile. As a result, a high supporting force and a horizontal resistance can be exhibited, the economic effect is increased, and it is also an environmental measure. SOLUTION: A lower pile A of a double type connected steel pipe sheet pile 1 in which parallel steel pipes 2 are integrally connected to each other by a connecting plate and a joint 3 is provided on a side opposite to an interconnecting side of the steel pipes 2 is provided underwater 6. , And is driven by a vibro hammer 10 so that a tip of a predetermined length enters from the underwater bottom surface 9.
A stirring excavator with an enlarged head is inserted into the lower pile A, and the lower part of the connected steel pipe sheet pile 1 is improved with the agitating excavator so that the improved portion is hardened. Are connected to each other and driven to a predetermined depth, and the adjacent connected steel pipe sheet piles 1 are appropriately connected to each other by coupling the joints 3 to each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel pipe sheet pile construction method for performing cut-off work in construction work in oceans and rivers.

[0002]

2. Description of the Related Art When constructing a structure such as a bridge pier in water, a (temporary) shut-off work using a steel pipe sheet pile is performed to shut off the periphery of the target structure.

The steel pipe sheet pile used for such a cut-off work has a joint formed on the left and right peripheral sides of the steel pipe, and the joints are connected to successively connect the pipes. The shape of the joint is various, such as a box shape and a T shape, a C shape, a C shape and a T shape, and the like.

Further, the steel pipe sheet pile may be driven by a driving (pile driving) machine using a diesel pile hammer, but this causes a large noise and vibration associated with the driving, which causes construction pollution.
Therefore, methods such as simultaneous drilling with a hydraulic jack and press fitting with a vibro hammer are also adopted while reducing the fitting resistance by earth drilling by earth auger drilling and drilling in steel pipes, but in each case, one steel pipe is set. It is something that goes.

[0005]

[Problems to be Solved by the Invention] In construction work in oceans and rivers, water pollution, which is regarded as pollution caused by construction, has become a social problem, and particularly sludge accumulated up to the present,
In the construction work on the accumulated soft ground, foundation work is performed under special conditions of underwater, and various secondary pollutions such as soil improvement and water pollution due to chemical injection method are often generated.

[0006] In ocean construction, unlike land, it is possible to transport long objects by sea, and most of them are planned and constructed with a single piece. Has a high resistance during driving (blockage in the adhesive friction steel pipe), and driving on hard ground cannot be handled only by increasing the size of the vibro hammer, and the jet method using water or air is often used as an auxiliary method. .

This auxiliary construction method by the jet construction method disturbs the target steel pipe peripheral surface or the soil at the tip of the jetting method, resulting in a water gap or a failure to obtain the planned supporting capacity of the supporting ground. there's a possibility that.

Further, it takes a lot of time and labor to insert the steel pipes into the excavation holes one by one as in the prior art and to place the steel pipes in the excavation hole, and at the same time, to insert the joint portion during the construction. Since there is a lot of resistance, it is easy to bend and it is difficult to secure the vertical accuracy of the steel pipe sheet pile itself.

Further, water pollution occurs due to the injection liquid at the time of solidifying the tip of the pile to obtain a stronger supporting force of the steel pipe and increasing the ground strength of the pile peripheral surface during the chemical liquid injection work.

The object of the present invention is to eliminate the disadvantages of the above-mentioned conventional examples, to prevent water pollution even in foundation work under special conditions of underwater, and to have good workability. As a steel pipe sheet pile, a conventional steel pipe sheet pile is used. The purpose of the present invention is to provide a steel pipe sheet pile construction method that can increase strength, and as a result, can exhibit high bearing capacity and horizontal resistance, increase economic effects, and serve as an environmental measure.

[0011]

In order to achieve the above object, the present invention firstly connects steel pipes arranged in parallel to each other integrally by a connecting plate, and provides a joint on the side opposite to the mutual connection side of the steel pipes. Built the lower pile of the double-type connected steel pipe sheet pile in the water,
Drive with a vibro hammer so that a certain length of tip enters from the underwater bottom, then insert a stirring excavator with an expanding head into this connecting steel pipe sheet pile lower pile, and improve the ground below the connecting steel pipe sheet pile with the stirring excavator. Before this improved portion is hardened, the upper pile is connected to the lower pile of connected steel pipe sheet piles and driven to a predetermined depth, and the adjacent connected steel pipe sheet piles are appropriately connected by joint mutual connection. The gist of the tie plate is that it is a tie plate having an H-shaped cross section in which the edges are joined to the peripheral surface of each steel pipe.

According to the present invention as set forth in claim 1, since the ground is improved in the soft portion up to the intended depth of the connected steel pipe sheet pile, the connected steel pipe sheet pile lower pile to which the upper pile is connected can be easily inserted. After the insertion of the connected steel pipe sheet piles is completed to such a desired depth, the ground improvement portion is solidified.

Since the lower pile of the connected steel pipe sheet pile is driven by a vibro hammer so that the tip of the fixed length enters from the underwater bottom, and the lower part is ground improvement, the improvement material injected by the improvement is underwater (underwater). It can be treated in steel pipes and there is no water pollution. In addition, due to the existence of ground improvement, it is not necessary to inject water for the purpose of stopping water at the joint joint portion below the pile below the steel pipe sheet piles. Especially, in this part of the ground improvement, the escape route of water can be eliminated and the water stopping effect is high.

According to the second aspect of the present invention, in addition to the above action, the tie plate is a tie plate having an H-shaped cross-section whose end edges are joined to the peripheral surface of each steel pipe, so-called H steel. so,
First, as a steel pipe sheet pile, a closed space is formed by surrounding with steel pipes on all sides. In other words, the steel pipe and the steel pipe are welded at the four end portions of the H steel, and by joining with the H steel, the steel pipe becomes an integrated steel pipe sheet pile, and the strength can be increased accordingly. Yes, it can withstand not only the short-axis direction but also the long-axis direction. The rigidity between the joints of conventional steel pipe sheet piles that have joints at both ends is not considered in the design, but the rigidity can be fully considered by joining two steel pipes with H steel, and the secondary moment in the short axis direction can be considered. Will increase.

[0015] It is more advantageous to place two at a time than to place one at a time, and the construction time can be greatly shortened. This is a great advantage over land construction. Moreover, since the two pieces are spliced with a predetermined accuracy, the construction accuracy is high and the vertical accuracy is improved.

Since the H steel is spliced, it is possible to easily reinforce and splice the short-axis directions of the cast steel pipes connected to each other. , Greater bending rigidity can be obtained in the long axis direction.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 5 are side views showing each step in one embodiment of the steel pipe sheet pile construction method of the present invention. In the drawings, 6 indicates water in the ocean or river, and 9 indicates an underwater bottom surface.

First, the steel pipe sheet pile used in the present invention will be described. As shown in FIGS. 6 and 7, the steel pipe sheet piles are H steel 4 as an H-shaped tie plate in which the edges of the steel pipes 2 to be juxtaposed are joined to the peripheral surface of each steel pipe 2 by the width of this H steel 4. This is a connected steel pipe sheet pile 1 which is integrally connected with a space provided, and a joint 3 is provided on the side opposite to such interconnection.

The H-steel 4 may be made of shaped steel or may be independently assembled in a factory by appropriate welding.
When using shaped steel, connect the left and right edges of the flange 4a to the steel pipe 2
It will be welded to the peripheral surface and these parallel flanges 4
A and the steel pipes 2 and 2 form a closed space 5 that surrounds and bends in all directions. In the figure, 4b is a web.

A joint 3 is provided on the side of the steel pipes 2 and 2 opposite to the interconnection side of the H steel 4 to form a double type steel pipe sheet pile 1. The joint 3 may be of various types as in the conventional example, and is not particularly limited. In the example of this embodiment, the slit 3a is used.
The tubular body having a C-shaped cross section, which is a ring body having
Welded to the peripheral surface of the. The joint 3 is provided right next to the steel pipe 2, but this slit 3a is not directly next to the joint 3 but opens diagonally. When the joints 3 face each other, the slit 3a opens in a symmetrical direction, The joints 3 mesh with each other via 3a so as to enter each other.

The joint 3 is not limited to the illustrated example, and in another embodiment, one male part is one piece, and the other male part is inserted into the female part by two pieces having a gap of two pieces. It may be a simple form as described above. Although not shown, the steel pipes 2 can be joined at an angle by bending or bending the juxtaposed flanges 4a.
This is suitable for connecting and arranging the steel pipe sheet piles 1 in a circular shape having a small diameter such as a ring beam. If the steel pipe sheet pile 1 is a circular shape such as a ring beam and has a relatively large diameter, it is possible to adjust only the meshing angle of the joint 3.

First, as shown in FIG. 1, the lower pile A of the above-mentioned double type connected steel pipe sheet pile 1 is built in the water 6, and the vibro hammer 10 is used so that the tip of the fixed length (4 to 5 m) enters from the underwater bottom surface 9. To set.

The collective placement of a plurality of steel materials by the vibro hammer 10 has a long history of construction, and the hydraulic chuck 10b is used.
Vibration is given by suspending several places of the steel pipe sheet pile 1 of the present invention at the same time by using the adapter 10a having the.

In addition, the lower pile A of the double type connected steel pipe sheet pile 1 is connected to each other by the joint 3 so that several tips are inserted from the underwater bottom surface 9 by a certain length (4 to 5 m) so that the vibro hammer 10
In addition to the method of connecting the upper piles B as will be described later after the driving is performed with, the method of connecting the upper piles B one by one can be considered.

Next, the stirring excavator 11 with the expanding head 11a is inserted into the lower pile A of the connected steel pipe sheet pile 1, and the ground excavation 12 is performed below the connected steel pipe sheet pile 1 by the stirring excavator 11. Although various configurations of the expansion head 11a are possible,
One example thereof is the case where members connected by a shaft are pushed apart as shown in FIGS. 8 and 9, or a screw blade is provided with an auxiliary cutter for expanding the diameter so that it can be projected by rotation, though not shown. .

The main body excavating shaft 11c of the stirring excavator 11 may be only a screw shaft provided with a screw, but the lower N
In the ground with a high value, a rod-shaped or spiral blade-shaped stirring blade 11b is provided above the portion where the screw is further provided. Although illustration is omitted, in soft ground, the stirring blade 11b may be provided. Ground improvement 12 is enlarged head 11a
By pouring hardener such as cement milk from the above and stirring with excavated earth and sand to form soil concrete.

Further, if the stirring excavator 11 with the expanding head 11a has a double excavating shaft 11c of a multi-spindle type, one driving device can simultaneously drive two excavating machines 11c for rotation. The ground improvement 12 can be performed by inserting the excavation shafts 11c into the steel pipes 2 and 2 of the double type connected steel pipe sheet pile 1 and excavating the lower part of the connected steel pipe sheet pile 1, respectively.
At that time, the expanding head 11a is made of H steel 4 with an H-shaped connecting plate.
It enables excavation including the width of the joint and the width of the joint 3.

Before the portion of the ground improvement 12 is hardened, as shown in FIGS. 4 and 5, the lower pile A of the connecting steel pipe sheet pile 1 is further connected to the upper pile B by welding or the like, and the vibro hammer 10 is driven to a predetermined depth. Set up.

The connection between the lower pile A and the upper pile B can be selected either for each connecting steel pipe sheet pile 1 or for simultaneously connecting a plurality of connecting steel pipe sheet piles 1. Further, a joint between adjacent connecting steel pipe sheet piles 1 can be selected. Coupling among the three will be performed accordingly.

It should be noted that, after the connected steel pipe sheet pile 1 is driven to a predetermined depth, the root solid material may be poured out to form the root solid 13.

FIG. 7 shows another example of the connected steel pipe sheet pile 1. The steel pipe sheet pile 1 is an H-shaped connecting member in which the flange edges of the steel pipes 2 arranged in parallel are connected to the peripheral surface of each steel pipe 2. In the above embodiment, the steel 4 is integrally connected to the H-shaped steel 4 with a gap corresponding to the width of the H-shaped steel 4, and the male joint 7 and the female joint 8 are provided on the side opposite to the interconnection. Same as the above, but the male joint 7 and the female joint 8 are the same as the mutual connecting members of the steel pipe 2 and have the H-shaped cross section and are composed of the combination of the flanges 7a, 8a and the webs 7b, 8b.
The edges of the flanges 7a and 8a are joined to the peripheral surface of the steel pipe 2. The male joint 7 is slightly smaller than the female joint 8.

In this way, the joint can be joined as an H-shaped cross section to increase the strength due to the presence of the web, and it is possible to receive the proof stress not only in the minor axis direction but also in the major axis direction. That is, since the shearing force acts substantially in the tube axis direction, it is possible to effectively reinforce by providing a reinforcing member called a web along the tube axis direction. Further, the joints can be fitted together simply by overlapping the flange ends, and a tight sealed space can be obtained in close proximity so that the flange tip of one joint abuts the web of the other joint.

[0033]

As described above, the steel pipe sheet pile construction method of the present invention is capable of preventing water pollution even during foundation work under special conditions of underwater, and has good workability. It will be stronger than the steel pipe sheet pile, and as a result, high bearing capacity and horizontal resistance can be exhibited, the economic effect will be increased and it will be an environmental measure.

[Brief description of drawings]

FIG. 1 is a side view showing a first step in one embodiment of a steel pipe sheet pile method of the present invention.

FIG. 2 is a side view showing a second step in one embodiment of the steel pipe sheet pile method of the present invention.

FIG. 3 is a side view showing a third step in one embodiment of the steel pipe sheet pile method of the present invention.

FIG. 4 is a side view showing a fourth step in one embodiment of the steel pipe sheet pile method of the present invention.

FIG. 5 is a side view showing a fifth step in one embodiment of the steel pipe sheet pile method of the present invention.

FIG. 6 is a plan view showing a first example of a connected steel pipe sheet pile used in the steel pipe sheet pile method of the present invention.

FIG. 7 is a plan view showing a second example of a connected steel pipe sheet pile used in the steel pipe sheet pile method of the present invention.

FIG. 8 is a side view of the expansion head of the stirring excavator with the expansion head.

FIG. 9 is a bottom view of the expansion head of the stirring excavator with the expansion head.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Steel pipe sheet pile 2 ... Steel pipe 3 ... Joint 3a ... Slit 4 ... H steel 4a ... Flange 4b ... Web 5 ... Sealed space 6 ... Underwater 7 ... Male joint 7a ... Flange 7b ... Web 8a ... Flange 8b ... Web 8 ... Female joint 9 ... Underwater bottom surface 10 ... Vibro hammer 10a ... Adapter 10b ... Hydraulic chuck 11 ... Stirring excavator 11a ... Expansion head 11b ... Stirring blade 11c ... Excavation shaft 12 ... Ground improvement 13 ... Root solid A ... Lower pile B ... Upper pile

Claims (2)

[Claims] 1. A lower pile of a connecting type steel pipe sheet pile of a double type in which steel pipes arranged in parallel are integrally connected by a connecting plate, and a joint is provided on the side opposite to the connecting side of the steel pipes. Drive with a vibro hammer so that the tip of a certain length enters from the bottom, then insert a stirring excavator with an expanding head into the lower pile of the connecting steel pipe sheet pile, and improve the ground below the connecting steel pipe sheet pile with the stirring excavator. A steel pipe characterized by further connecting an upper pile to a lower pile of connected steel pipe sheet piles and driving them up to a predetermined depth before the improved portion is hardened, and connecting adjacent steel pipe sheet piles to each other by joint mutual connection. Yaita construction method. 2. The steel pipe sheet pile construction method according to claim 1, wherein the tie plate is a tie plate having an H-shaped cross section in which edges are joined to the peripheral surface of each steel pipe.