JPH0213609A - Steel sheet pile and work method of steel sheet pile wall using it - Google Patents

Abstract

PURPOSE:To decrease grip resistance at the time of driving in and a necessary hanging capacity of a crane without disturbing sheeting and water-stopping capacity, by eliminating a grip on the side which is fit to a preceding steel sheet pile from the bottom end within a range of driving-in length to supporting ground layer. CONSTITUTION:Among grips 4a, 4b arranged on both sides of a steel sheet pile 3, the grip 4a on the side which is fit to a preceding steel sheet pile is eliminated from the bottom end along a specified measure 5 within a range of driving-in of the steel sheet pile 3 to a supporting ground layer. Hanging capacity of a crane can be smaller by an amount corresponding to this specified measure 5. And a length which has to be driven in against grip resistance within a supporting ground where the biggest resistance exists can be reduced by the specified measure 5. In upper ground layer than the supporting ground, grips are fit together and necessary sheeting and water-stopping are performed.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a steel sheet pile widely used in river revetment and port quay wall construction, and a method of constructing a steel sheet pile wall using the same.

``Prior Art'' As is well known, a steel sheet pile has joint grips 2, 2 at both ends, as shown in FIGS. Steel sheet piles 1 of the same type are placed next to the steel sheet piles 1 that are placed in advance, and earth retaining and water-stop walls are constructed.

Since the grip 2.2 mentioned above forms a joint between the water-stop walls, it is designed to fit tightly, and the resistance during driving is extremely large.

Incidentally, the breakdown of the total resistance R0 when driving steel sheet piles is as follows.

RO = RG + R + R, (ratio of long sheet piles) R, average lip resistance 70% RT: tip resistance 〃 5% RP: peripheral friction resistance 〃 15% It can be seen how much weight the grip resistance R0 occupies.

Regarding the grip resistance R6 mentioned above, the following matters have been found.

In other words, in the figure, when a steel sheet pile 1'' of the same type is placed adjacent to a steel sheet pile 1 having already driven normal U-shaped grips 2, 2 by fitting the grips together, The relationship between the driving force P and the rooting depth h requires a very large driving force P when the joist depth h is about 6 m.

The reason for this is that the grip of the existing steel sheet pile 1 is filled with earth and sand with a high density depending on the depth, and when the next steel sheet pile 1 is fitted into the previous steel sheet pile 1 and driven in, the grip initially Since the soil density inside the steel sheet pile 1 is small, some of the soil is removed from the grip opening of the steel sheet pile 1, and the remaining soil is removed from the fitted steel sheet pile 1.
As it penetrates, it is compressed downward by its grip tip.

As driving continues, the soil within the grip becomes dehydrated, leaving almost no voids, and is compressed to the point that it approaches its true specific gravity. The position at which this state occurs varies depending on the soil quality, driving conditions, etc., but since the driving force P increases from the point when the tip of the steel sheet pile 1'' passes 6 m, the position where the steel sheet pile 1 below the tip of the steel sheet pile 1'' increases. The sediment density inside the grip is quite high.

Therefore, the trailing steel sheet pile 1' has to push through the high-density earth and sand trapped in the grip of the leading steel sheet pile 1, which creates a large amount of resistance.

Regarding high resistance on ridges, if the grip is weak, the grip of the steel sheet pile that should be in the fitted state will open, the connection will come off, and earth and sand will flow out. The reality is that various proposals have been made to increase the strength of the grip, such as No. 83313.

``Problem to be solved by the inventionj'' However, the conventional method of increasing the strength of the grip as a countermeasure to the high resistance when driving steel sheet piles is not rational in view of the actual construction situation.

In other words, as mentioned above, there is a steel arrow v below the tip of the steel sheet pile l''.
The soil density in the grip of i1 becomes considerably high, and this tendency should be even more pronounced in the supporting ground layer where the steel sheet pile must penetrate, but the supporting ground layer has neither earth retaining ability nor water stopping ability. There is no need for side berms, and earth retaining and water supply are necessary due to the soft upper layer of the supporting ground layer in which the steel sheet piles are embedded, and the permeable ground layer, and are not possible with conventional methods on ridges. This is because no unnecessary difficulties have been resolved in the supporting ground layer.

As a result of unresolved resistance, grip resistance increases as steel sheet piles become longer, resulting in frequent construction problems such as when descending.

In addition, regarding the lengthening of steel sheet piles, when fitting the trailing steel sheet piles, the size of the crane's lifting capacity (tall)
As a result, there are many falls accidents due to lack of ability.

In view of the situation on ridges, the present invention has developed a steel sheet pile that can drastically reduce the resistance in the supporting ground layer where the most severe driving resistance occurs, yet still maintain the desired soil retaining and water-stopping ability. The purpose of this study is to provide a construction method for steel sheet pile walls.

"Means for Solving the Problem" In order to achieve the above object, in the steel sheet pile of the present invention, the grip on the side to be fitted to the preceding steel sheet pile is moved from the lower end within the range of penetration of the supporting ground layer. It has been decided that it will be deleted.

Further, using such steel sheet piles, a grip of a trailing steel sheet pile whose lower end has been removed is fitted to the leading steel sheet pile to construct a steel sheet pile wall.

"Operation" In the steel sheet pile configured as described above, since there is no fitting between the grips in the supporting ground layer where the grips have been removed, grip resistance does not occur.

However, in the strata above the supporting ground, the grips are only fitted, so that the specified earth retention and water stoppage can be achieved.

Furthermore, when fitting the trailing steel sheet pile, the fitting position is lowered by the amount of grip removed, so the lifting capacity required of the crane becomes smaller.

"Example" To explain an example with reference to the drawings, the first part shows an embodiment of the present invention in a steel sheet pile 3 having a U-shaped cross section, and the grips 4a and 4b provided on both sides are The grip 4a on the side that fits into the steel sheet pile has a predetermined size 5 from the lower end.
has been deleted over the years.

The predetermined dimension 5 is set within the support ground layer penetration range of the steel sheet pile 3.

FIG. 2 shows a construction mode of a steel sheet pile wall 6 using such a steel sheet pile 3. As shown in the figure, the trailing steel sheet pile 3' is assembled to the preceding steel sheet pile 3, but at this time the grip is fitted from above the predetermined distance by 5 minutes, so the lifting capacity of the crane is reduced accordingly. Small is good.

Once the grips are fitted, they are driven into the supporting ground 7 while being guided, as described above.

In the supporting ground 7, it is unnecessary to drive the fitting portion between the grips by a predetermined size of 5 minutes.

That is, when driving into the support ground 7 with the highest resistance, the length that the tip must penetrate due to grip resistance can be reduced by the predetermined dimension 5.

In this way, the formed steel sheet piles 6 are firmly supported by the lower end of each steel sheet pile being embedded in the supporting ground 7, and the soft ground layer 8 above the supporting ground 7 has a grip. They are connected by fitting between them and exhibit a certain earth retaining and water stopping ability.

FIGS. 3a to 3d are plan views of steel sheet pile walls made of various U-shaped, Z-shaped, H-shaped, and box-shaped steel sheet piles, and the present invention can be practiced in any of these cases.

"Effects of the Invention" Since the present invention is configured as described above, it produces the effects described below.

As the length of the fitting portion that produces grip resistance is shortened, grip resistance is significantly reduced and driving speed and workability are increased.

Furthermore, since there is no penetration into the supporting soil layer, which has the highest resistance, the ease of driving is significant.

As a result of lowering the position of the fitting between the grips during driving,
The lifting capacity of the crane can be lowered, thereby avoiding the inconvenience of having to increase the lifting capacity of the crane as steel sheet piles become longer.

[Brief explanation of the drawing]

Figure 1 is an overall view of the steel sheet pile of the present invention, Figure 2 is an explanatory diagram of the construction mode of the steel sheet pile wall of the present invention, Figures 3 a - d are diagrams of embodiments of the present invention in steel sheet piles of various shapes, FIGS. 4a and 4b are explanatory views of the pouring of steel sheet piles. 1.1”...Steel sheet pile, 2...Grip, 3,3
゛...Steel sheet pile, 4a, 4b...Grip, 5
...Predetermined dimensions, 6. Steel sheet pile wall, 7. Supporting ground, 8. Soft ground layer. Busoli A6 a, b. C1d.

Claims (2)

[Claims] (1) A steel sheet pile characterized in that the grip on the side that fits into the preceding steel sheet pile is removed from the lower end within the range of penetration of the supporting ground layer. (2) A method of constructing a steel sheet pile wall, characterized in that the grip of the steel sheet pile according to claim 1 with its lower end removed is fitted into the grip of the preceding steel sheet pile and driven into the grip.