JPS63134713A - Temporary coffering construction with continuous wall - Google Patents

Abstract

PURPOSE:To construct a continuous wall economically in a short period, by setting a reinforcing beam previously in either internal or external space formed between the continuous wall and a coffering work. CONSTITUTION:A coffering member 10 is driven to the specified depth of sea- bottom ground E, and fill earth 12 is cast. Then, a reinforcing beam 14a is set, and after that, by casting the fill earth 12 again and arranging reinforcing beams 14b, 14c, a continuous wall 16 is constructed. Then, the construction of the continuous wall 16 is finished, and a temporary coffering work is completed, and water inside the separated temporary coffering work is discharged, and the work is dried up, and objective structures are constructed in the temporary coffering work. As a result, under profitable conditions, the temporary coffering work of a large depth and a large scale can be constructed.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to a temporary cofferdam construction method using a continuous underground wall, and particularly relates to an improvement in a temporary cofferdam construction method applied when drying up the inside of a cofferdam. .

(Prior Art) As is well known, when constructing a structure such as a bridge pier footing in a river or the sea, a temporary cofferdam is formed in the water body,
The water inside the cofferdam may be drained to make it dry, and construction work may be carried out under the same conditions as on land.

As this type of temporary cofferdam, construction methods using steel sheet piles are widely adopted.

Temporary cofferdam construction methods using steel sheet piles are easy to construct and handle, but they do not provide sufficient resistance to external forces for sealing off large and deep bodies of water.

Therefore, a temporary cofferdam method has been proposed in which a water body is closed off with steel sheet piles, and filler soil is poured into the cofferdam, and a continuous wall of concrete that reaches from the seabed ground to above the water surface is formed during the cofferdam construction. .

However, such a temporary cofferdam construction method using a continuous wall has the following problems, particularly when water in the cofferdam is drained and dried up.

(Problem to be solved by the invention) In other words, when the inside of a temporary cofferdam is dried up, the surrounding soil and water pressure acts on the temporary cofferdam, but these external forces cannot be overcome by temporary cofferdam construction using continuous walls. As mentioned above, it is applied to deep and large-scale construction, so it is quite large. Therefore, in order to resist the external force applied to the temporary cofferdam when it dries up, the wall thickness of the continuous wall must necessarily be increased.

By the way, this type of temporary cofferdam is usually temporary equipment used to safely and quickly construct a construction object, and is scheduled to be removed after the construction is completed. It is desirable to have a temporary cofferdam that is safe, and how to construct a safe temporary cofferdam at low cost is an extremely important technical concern.

However, the above-mentioned construction method requires increasing the wall thickness of the continuous wall, which poses a major economic problem.

Here, it is possible to reduce the wall thickness of the continuous wall and form a reverse wall on the inside of the continuous wall when drying up the inside of the cofferdam, but this construction method The problem is that it takes time.

The present invention has been made in view of these conventional problems, and its purpose is to provide a temporary cofferdam construction method using continuous walls that can be constructed economically and in a short period of time.

(Means for Solving the Problems) In order to achieve the above object, the present invention forms a cofferdam in a water body, forms a continuous wall within the cofferdam, and then surrounds the cofferdam with the continuous wall. In the construction method of drying up the inside, a reinforcing beam is installed in advance in either the inner or outer gap formed between the continuous wall and the cofferdam.

(Function) According to the temporary cofferdam construction method with the above configuration, reinforcing beams are provided on either the inside or the outside of the continuous wall, so when the inside of the cofferdam is dried up, it will resist external forces applied to the cofferdam. Since the continuous wall and the reinforcing beam cooperate to provide resistance, there is no need to increase the wall thickness of the continuous wall.

Furthermore, since the reinforcing beams are installed in advance when constructing the cofferdam, the construction period for the temporary cofferdam will not be prolonged.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view showing an embodiment of the temporary cofferdam construction method using continuous walls according to the present invention in the order of steps.

In the construction method shown in FIG. 1, first, as shown in FIG. I
! It is poured to a predetermined depth of E, and filling earth and sand 12 is placed between the cofferdams 10 and 10.

When the filling soil 12 is deposited to a predetermined thickness on the seabed ground E, the first reinforcing beam 14a is installed, and then the filling soil 12 is put in again and the second and third reinforcing beams 14b, 14 are installed.
Install C.

Here, each reinforcing beam 14a, b, c is a cofferdam 1.
It is located in the outer gap 17 between the continuous wall 16 and the cofferdam 10 provided at approximately the center position between 0 and 10, and is located on the outside of the continuous wall 16 so as to follow the outer peripheral shape of the continuous wall 16. will be installed.

Furthermore, if the object to be constructed within the cofferdam has a circular cross-section, the most practical way for each of the reinforcing beams 14a, b, and c is to form a ring of steel members having an appropriate width and thickness. , reinforcing beams 14a, b, C are solidified with a solidifying agent containing special additives to suppress separation in water. c.
You can also use it as

When the reinforcing beams 14a, b, and c are installed in steps, as shown in FIG.
As shown in b), a continuous wall 16 is constructed approximately in the center between the cofferdams 10-10.

The continuous wall 16 is formed by excavating the filling earth 12 and the seabed E while filling it with muddy water, erecting reinforcing bars in the excavated hole, and then pouring concrete.

When the construction of the continuous wall 16 is completed, the temporary cofferdam is completed, so as shown in Fig. 1(C), reinforcement is completed! 814a, b, c
Water is drained and dried from the area where the cofferdam is not installed, that is, inside the cofferdam, and the target object is constructed while the cofferdam is being constructed.

Now, if you construct the temporary cofferdam (n) using the method described above, the first
As shown in Figure (C), when the temporary cofferdam is dried up, the reinforcement beams 14a, b,
c and the continuous wall 16 will cooperate and oppose each other,
The continuous wall 16 is divided by the reinforcement beams 14a, t+, and c.
The wall thickness of the can be reduced.

Furthermore, when constructing internal concrete during temporary cofferdam construction, a sequential method of pouring concrete from the bottom to the top can be used, which also shortens the construction period.

FIG. 2 shows another embodiment of the temporary cofferdam construction method using a continuous wall according to the present invention, and only its characteristic points will be described below.

In this embodiment, reinforcing beams 148 to 14c are buried in advance in the inner gap 18 formed between the fastening wall 16 and the cofferdam 10.

When the interior of the cofferdam 1.0-10 is dried up, when the reinforcing beams 14a to 14C are sequentially exposed from the upper side, a connecting material 2 such as concrete is inserted between the reinforcing beams 14a to 14C and the continuous wall 16. The reinforcing beams 14a to 14c and the continuous wall 16 are integrated with each other as shown in FIG. 2(b).

Even if the temporary cofferdam is created as described above, the same effect as in the above embodiment can be achieved.

(Effects of the Invention) As explained above, according to the temporary cofferdam construction method using a rapid extension wall according to the present invention, it is possible to achieve deep and large cofferdam construction under economical and advantageous conditions, which is the most important aspect of this type of construction method. Large-scale temporary cofferdams can be constructed.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing the steps of the construction method of the present invention in order, and FIG. 2 is a longitudinal sectional view showing another embodiment of the same method in order of steps. 10... Cofferdam material 12... Filling earth and sand 14a, b, c... Reinforcement beam 16... Continuous wall

Claims (2)

[Claims] (1) In a construction method in which a cofferdam is formed in a body of water, a continuous wall is formed within the cofferdam, and the inside surrounded by the continuous wall is dried up, the cofferdam is formed between the continuous wall and the cofferdam. A temporary cofferdam construction method using a continuous wall characterized by installing a reinforcing beam in advance on either the inner or outer gap. (2) A temporary cofferdam construction method using a continuous wall, characterized in that the reinforcing beams are buried in multiple stages at predetermined intervals in the depth direction along the continuous wall.