JPS6363817A - Removal of continuous concrete wall temporarily formed under water - Google Patents

Abstract

PURPOSE:To make the operation of removing a continuous concrete wall temporarily formed under water easier by a method in which connectors such as bolts, etc., are removed, and temporary parts exposed under water are separated by external forces simply. CONSTITUTION:The reinforcing bars 10 of a continuous concrete wall are connected with detachable connectors 7 between the upper and lower parts of the bottom face under water to be separated later, where the connectors 7 are exposed from the surface of the wall 1. In removing the wall 1, the connection is released, external forces are applied to the exposure in water of the wall 1, and the separating portion by cutting of the wall 1 as a breaking point is cut off. The operation of removing the continuous concrete wall 2 can thus be made easier.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention provides underwater 41! This invention relates to a method for easily removing an underwater temporary concrete continuous wall for constructing the foundation of an S structure after the foundation has been constructed.

(Background of the Invention) When constructing a foundation for a bridge pier, etc., an artificial island is created by closing off a body of water, and the inside of the island is roughly demolished.

By the way, when constructing a foundation under deep water, ordinary G14 pipes or steel sheet piles cannot sufficiently resist water pressure.

As a countermeasure in this case, it is possible to adopt continuous walls made of reinforced concrete as a closing structure.

However, with reinforced concrete continuous walls, the robustness, which is a characteristic of concrete continuous walls, has been an obstacle, especially when removing underwater exposed parts after construction of the underwater structure is completed.

The purpose of this invention is to solve the above-mentioned problems by artificially creating unreinforced parts in concrete continuous FA walls and making it possible to remove these parts as brittle failure points.

In order to achieve the above-mentioned object, the method of the present invention involves connecting reinforcing bars of a continuous concrete wall in advance by connecting and connecting the upper and lower parts of the reinforcing bars with the water bottom surface as a separation part via a removable coupling tool, and connecting the reinforcing bars of a continuous concrete wall to the continuous wall. The continuous wall is exposed to the surface of the wall, and upon removal, the connecting joint is removed, and then an external force is applied to the underwater exposed part of the continuous wall, and the separated part is used as a brittle fracture point to separate the upper and lower parts. Features.

(Function) According to the scattering method with the above configuration, continuous concrete walls can be cut into pieces of a certain size and shape, and the scattering work and transportation are also easy! It can be done on 1t11.

(Example) Hereinafter, an example of the present invention will be described in detail using the drawings.

FIG. 1 is a front sectional view showing the completed state of construction of a bridge pier to which the method of this invention is applied.

In the completed construction state at J3 in the figure, the continuous concrete wall 1 that surrounds the tunnel is used as the deadline, and the inner concrete 2 is placed underground, and the top plate 3 is placed on top of it. Pier 4 protruding from sea level ~ VL
It is under construction.

The concrete continuous wall 1 consists of a main body part 1a buried under the seabed and a temporary part 1b exposed to the sea and above.

It is an object of the present invention to separate and scatter this temporary part 1b as a cut-off part E2 with the bottom surface as a boundary.

This separation part is the second. As shown in an enlarged view in FIG. 3, it is equipped with a pair of upper and lower U-shaped joints 5 and 6 that connect to reinforcing bars arranged vertically inside the concrete wall, respectively.
The flange joint surfaces of the joints 5.6 are fastened with bolts 7 to connect the reinforcing bars on the main body portion 1a side and the temporary portion 1b side. The inner joint 5.6 is placed in an exposed state on the wall surface of the continuous wall 1, and its exposed portion is covered with a protective sheet 8.

FIG. 4 is a perspective view showing the connection structure of reinforcing bars in the same part, and the inside of each joint 5.6 has the above-mentioned iron i.
10 are vertically mounted at appropriate intervals, and the upper joints 6 are connected by round steel 11.

Note that the round steel 11 is coated, for example, on its outer periphery in order to prevent it from adhering to concrete.

Therefore, the temporary part 1b of the continuous wall 1 configured as described above
To remove the bolt, fill the interior surrounded by the continuous wall 1 with seawater, balance the pressure with the open sea, remove the bolt from the flange of the joint 5.6 by cutting, etc., and then As shown in FIG. 5, a vibro hammer 1 is suspended from a crane 12 installed on a barge or the like.
The chuck 15 of No. 4 is connected to the upper end of the temporary part 1b, and the vibro-hammer 14 is moved.
It is possible to perform brittle fracture starting from the cut-off portion E, which is the most fragile portion, and to remove this portion as a cutting line.

As shown in FIG. 6, the concrete continuous wall 1 is constructed by connecting one panel 112 to the end of the preceding panel 111 via a pouring joint 110.
A rhombus-shaped auxiliary hole 16 for separation extending across each panel 111, 112 is vertically passed through the perforation joint 110, and upon removal, the auxiliary hole 16 is filled with an expanding agent. The swelling agent presses the wall surface as shown by the arrow. Here, the auxiliary hole 16
are right-angled or acute-angled surfaces in each panel 111, 112 that create opposite expansion pressures, resulting in a total displacement of both panels 111 and 112 in opposite directions and shearing of this section, which facilitates separation. be able to. Therefore, prior to additional shooting using the vibro-hammer 14,
By filling the auxiliary hole 16 with the swelling agent, the temporary part 1b is separated at the bottom and both sides, and becomes a panel with a predetermined shape and size, so that the transportation work after removal is also a bacterial one. . In addition, as an example of the shape of the auxiliary hole 16 in the concrete pouring joint part 110, as shown in FIG.
Those whose intersection angle with respect to 10 is an acute angle, or <b
>, as shown in (c), a curved shape can be considered, and in short, the shape should be such that the panels 111 and 112 can be separated most efficiently.

(Effects of the Invention) As explained in detail in each of the embodiments above, according to the method of the present invention, when constructing an underwater structure, a solid closing structure with continuous concrete walls can be obtained, and a state that provides sufficient durability can be achieved. You can build underwater structures and their foundations. After construction is completed, by removing bolts and other connections, the temporary portion exposed underwater can be easily separated by external force, making removal work easier.

In addition, as shown in the embodiment, by forming an auxiliary hole for separation in advance at the joint part of a concrete continuous wall and filling this part with an expanding agent, it is possible to easily separate the panel joint parts.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing the completed state of construction of a bridge pier to which the method of this invention is applied, Fig. 2 is an enlarged front sectional view of Agl5 in Fig. 1, Fig. 3 is a sectional view on the same side as t, Fig. 4 is a perspective view showing the connection structure of reinforcing bars in the same part, FIG. 5 is an explanatory diagram during removal work, FIG. 6 is a plan view of the concrete pouring joint, and FIGS. 7(a) and (b). (C) is a plan view showing another example of the shape of the auxiliary hole of the splicing part. 1...Concrete continuous wall 1a...Main part 1b...Temporary part 2.3.
...Foundation (2...inner concrete 3...hinge)4...
...Bridge pier (underwater structure) 5.6...Joint 7...Bolt 10...
Reinforcing bar patent applicant Obayashi Co., Ltd.
Person Patent Attorney - Color Ken Shaft Circumference
Patent Attorney Masatoshi Matsumoto Figure 1 Figure 4 Figure 6 +i+ 0 +to ++2 Figure 3 Figure 2 Figure 5 (C)

Claims (1)

[Claims] (1) A method of closing off a body of water with an underwater temporary concrete continuous wall, constructing a foundation for an underwater structure inside the closing, and removing the upper part of the underwater structure of the continuous wall after completion of construction of the foundation, the method comprising: The reinforcing bars of the continuous wall are connected in advance through removable connectors between the top and bottom of the continuous wall, using the water bottom as a separation point, and the connectors are placed exposed on the wall surface of the continuous wall and removed. A method for removing an underwater temporary concrete continuous wall, characterized in that the connecting joint is removed at the time, and then an external force is applied to the underwater exposed part of the continuous wall to separate the upper and lower parts using the separated part as a brittle fracture point.