JPH0448890B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention is applicable to when excavating underwater ground to construct a bridge pier, etc., to shut off water around the excavation with a double cofferdam, or to construct a work jetty underwater. This invention relates to a method for constructing a double fence using steel pipe sheet piles and straight sheet piles to stop water around the bridge when constructing a bridge, and a method for connecting the head of the straight sheet piles.

[Conventional technology]

To install a double fence like the one above underwater, such as at sea, conventional steel pipe sheet piles are generally used. The corresponding heads of the steel pipe sheet piles are connected using tie rods, etc., and filling materials such as earth and sand are put into the area of the double fence surrounded by the steel pipe sheet piles.

However, with the above conventional method, large waves attack areas facing the open sea, etc., so after the steel pipe sheet pile is installed and until the filling material is completed, the steel pipe is independent from the waves. There is a problem in that the work must be carried out in a very unstable condition as resistance must be provided only with sheet piles, and steel pipe sheet piles with a very large diameter must be deeply rooted, and double fences are not suitable. Bolting or welding the heads of steel pipe sheet piles together at sea is difficult, and it is not easy to create a rigid frame structure with sufficient rigidity.

[Problem for which the invention is to be decided]

The present invention was made in order to solve the above-mentioned conventional problems, and provides a method for constructing double fences that can be constructed stably and economically even in places where large waves attack. The problem to be solved is to provide a method for connecting the heads of the steel pipe sheet piles used at that time, which provides sufficient rigidity and economically connects the heads of the steel pipe sheet piles to easily form a rigid frame structure. It is.

[Means to solve the problem]

As a means to solve the above problems, the double fence construction method of the present invention alternates between steel pipe sheet piles whose tops are located above the water surface and straight sheet piles whose tops are located slightly above the water bottom surface. Continuously cast double fences on the underwater ground at predetermined intervals, and connect the corresponding heads of the steel pipe sheet piles of these double fences with connecting materials such as tie rods or shaped steel materials. on the straight sheet pile,
Additional straight sheet piles with appropriate heights divided from the water bottom to the water surface are butted together, and filling materials such as earth and sand are poured into the double fence to a height slightly below the top of the straight sheet piles. The work of filling the inside with
It is characterized by filling up to a predetermined height above the water surface, but in this case, if necessary, partitions made of alternately driven steel pipe sheet piles and straight sheet piles may be installed inside the double fence to perform filling. .

If you construct a double fence using this method, the waves will pass over the straight sheet piles between the steel pipe sheet piles, so you can construct the double fence in a stable condition without applying large forces such as waves to the steel pipe sheet piles. Can be done.

In addition, as a method for connecting the heads of steel pipe sheet piles that are cast into the underwater ground in the form of double fences as described above, the heads of each corresponding steel pipe sheet pile are connected to the lower part of both ends through the notches made inside the steel pipe sheet piles. Steel materials of appropriate length are rigidly tied together in advance, and a bottom plate with a shape that matches the inner diameter of the steel pipe sheet pile is connected to the bottom of the steel materials using connecting materials such as tie rods or shaped steel materials that are installed according to the existing layout. It is characterized by filling the upper part of the steel pipe sheet pile with concrete by closing the space between it and the connecting member with a plate, etc., thereby easily creating a rigid rigid frame structure.

〔Example〕

An example of construction of a double fence by applying the method of the present invention will be described below with reference to the drawings.

First, the construction method of the double fence in this example will be explained step by step.
As shown in the front view in Figure 2 and the side sectional view in Figure 2,
As shown in the enlarged plan view of Fig. 3, a steel pipe sheet pile 1 whose top end is located above the water surface WL and a straight sheet pile 2 whose top end is located slightly above the water bottom surface are joints provided at each side end. 3, the steel pipe sheet piles 1 are alternately and continuously driven into a double fence shape consisting of two rows spaced apart at a predetermined interval on the underwater ground B, and the corresponding heads of the respective steel pipe sheet piles 1 of these double fences are connected. Connect with material 4, such as tie rods or shaped steel.

Next, as a second step, as shown in the side sectional view in Fig. 4 and the front view seen from the inside of the double fence in Fig. 5, from the water bottom surface to the water surface WL
Additional straight sheet piles 2A having appropriate heights divided up to the top are butted against each other, but in this case, if water stoppage is required, they are butted together through a joint such as a packing to stop water. , Prevents leakage of filling sand.

Therefore, we carried out filling work by putting filling material 5 such as earth and sand into the double fence on the water bottom ground B where the straight sheet piles 2A were butted to a height slightly below the top of the straight sheet piles 2A. do.

Next, as a third step, as shown in the side sectional view in FIG. 6 and the front sectional view seen from inside the double fence in FIG. Then fill the inside of the double fence with the filling material 5 similar to that explained in the second step, and continue this work until the straight sheet pile 2C and the filling material 5 reach a predetermined height above the water surface WL. Do it until you reach it.

If necessary when carrying out the work in the second and third steps above, further steel pipe sheet piles 1A and straight sheet piles 2E are alternately and consecutively driven within the double fence as shown in the plan view of Fig. 8. Then, a partition is provided in the range indicated by
When it reaches a predetermined height above the water surface WL, the next partition is installed in the direction of arrow Y in Fig. 8, and the straight sheet piles 2A, 2B, 2C and filling material 5 are placed in order.
This will complete the construction of the double fence.

Next, a method for connecting the corresponding heads of the steel pipe sheet piles 1 cast in the double fence shape using connecting members 4 such as H-shaped steel will be explained. As shown in FIG. 10, which is a front sectional view of the main part in the direction of A-A in the figure, the cross-sectional shape of the connecting member 4 used to connect the corresponding heads of the steel pipe sheet piles 1, that is, the H-shaped steel member of this embodiment, is In addition, a notch 8 is provided inside the head of the steel pipe sheet pile 1, and a steel material 9 of an appropriate length rigidly connected to the bottom of both ends of the connecting member 4 is inserted through the cut into the head of the steel pipe sheet pile 1 to connect it. do.

The above-mentioned steel material 9 is rigidly connected to the bottom of both ends of the connecting member 4 in advance, but a bottom plate 10 having a shape matching the inner diameter of the steel pipe sheet pile 1 is attached to the bottom of the steel material 9 according to the dimensions of the site. This bottom plate 10 connects the steel material 9 to the steel pipe sheet pile 1.
One of the bottom plates 10 may be attached to the steel material 9 in advance, and only the other bottom plate 10 may be attached in accordance with the dimensions of the site.

After connecting the steel pipe sheet piles 1 of the double fence with the above-mentioned connecting members 4, the notches 8 inside the steel pipe sheet piles 1 and the connecting members 4
By closing the space between the two steel pipe sheet piles 1 with a plate 11 and filling the area indicated by double diagonal lines at the top of the steel pipe sheet piles 1 with concrete 12, a highly rigid rigid frame structure between the two steel pipe sheet piles 1 and the connecting member 4 is created. , formed without bolts or welding.

〔Effect of the invention〕

According to the double fence construction method of the present invention described above, when inserting filler material, the straight sheet piles are only constructed up to the bottom surface of the water, so there is a gap between the steel pipe sheet piles and the steel pipe sheet piles. There is a gap, and waves can freely pass over the straight sheet piles between them.Therefore, even if large waves attack, the steel pipe sheet piles do not have that much force applied to them, and their small cross section can resist them. This has the effect of reducing the depth of penetration, making construction work more economical and stable.

Further, the additional straight sheet piles can be constructed by simply inserting them onto the cast straight sheet piles and butting them together, so a stable state can be maintained by inserting the additional straight sheet piles to a height that corresponds to the height at which filling is to be performed.

Furthermore, the completed double-fence structure uses a combination of steel pipe sheet piles and straight sheet piles alternately, so it has the effect of being economical because it uses less steel.

On the other hand, according to the double fence steel pipe sheet pile head connection method of the present invention, the head connections of the corresponding steel pipe sheet piles are
It has the advantage that construction is carried out according to the dimensions of the site, and that a highly rigid rigid frame structure can be easily and economically formed simply by filling with concrete without using bolts or welding.

[Brief explanation of the drawing]

The drawings are a series of explanatory diagrams showing the working procedure in one embodiment of constructing a double fence by applying the method of the present invention, and FIG. 1 is a front view of the first step, and FIG. A side sectional view, Figure 3 is an enlarged plan view of Figure 1,
Fig. 4 is a side sectional view of the second step, Fig. 5 is a front view seen from inside the double fence of Fig. 4, Fig. 6 is a side sectional view of the third step, and Fig. 7 is a side sectional view of Fig. 6. A front view as seen from inside the double fence, Figure 8 is a plan view when partitions are installed in the second and third steps above, and Figure 9 shows the connecting members in Figure 2 connected to the corresponding heads of steel pipe sheet piles. FIG. 10 is an enlarged side view of the main parts explaining the connection method for connecting to the A-
It is a front sectional view of the main part in the A direction. 1... Steel pipe sheet pile, 2, 2A, 2B, 2C... Straight sheet pile, 4... Connecting material, 5... Filling material, 8... Notch, 9... Steel material, 10... Bottom plate, 11...
...Plate, 12...Concrete, B...Underwater ground, WL...Water surface.

Claims (1)

[Scope of Claims] 1. Steel pipe sheet piles whose tops are located above the water surface and straight sheet piles whose tops are located slightly above the water bottom surface are alternately and consecutively driven into the water bottom ground in the form of a double fence. , After connecting the heads of the corresponding steel pipe sheet piles of these double fences with connecting members, a straight sheet pile having a height divided appropriately from the water bottom surface to the water surface is butted on the above straight sheet pile, A construction method for a double fence using steel pipe sheet piles and straight sheet piles, in which the work of filling the double fence to a height slightly below the top of the straight sheet piles is repeated until a predetermined height is reached. 2. Steel pipes of appropriate length are rigidly connected to the lower parts of both ends of the corresponding heads of the steel pipe sheet piles cast in the form of double fences on the underwater ground, through cuts made inside the heads, and After connecting a bottom plate shaped to match the inner diameter of the steel pipe sheet pile to the lower part of the steel material using a connecting member installed according to the existing arrangement, the gap between the above notch and the connecting member is closed, and the upper part of the steel pipe sheet pile is filled with concrete. How to connect the head of double-fence steel pipe sheet piles.