JPS63312417A - Water construction of continuous wall using steel caisson - Google Patents

Abstract

PURPOSE:To construct a structure strongly supported on the ground in water by a method in which a steel caisson is set on the bottom under water and its foot is protected, the bottom ground in water below walls is excavated, a reinforcing bar cage is set, and concrete is placed. CONSTITUTION:A steel caisson 2 is set on an embed portion, and underwater concrete 3 is placed to the embed portion to stabilize the foot of the caisson 2 in the bottom in water. The bottom round below walls 2a and 2b is excavated, a reinforcing bar cage 7 is set in the aperture between the excavated portion 6 and the walls 2a and 2b, and concrete 8 is placed. A highly accurate and rigid continuous wall integrated with the steel caisson, the concrete, and a continuous underground wall constructed on the bottom ground in water can thus be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a construction method for constructing a foundation or a highly rigid frame by constructing a continuous wall underwater using a steel caisson.

``Prior art, problems to be solved by invention'' Conventionally, when constructing a continuous wall over water, the methods used were to create an artificial ground by reclaiming land, or to install a wall plate for each element. was.

However, the landfill method requires large-scale equipment and a long construction period, and has drawbacks such as the collapse of the reclaimed layer.

In addition, the method of installing a wall plate for each element requires the driving of reference piles with guides for installing the wall plate, which is not easy to do, and the accuracy of construction is low. There were some drawbacks.

"Means for Solving the Problems" In order to solve the above-mentioned conventional problems, the present invention installs a steel caisson with double inner and outer frame walls under the water bottom, and hardens the area near the bottom of the water. After stabilization, excavate the underwater ground between the inner and outer frame walls on this caisson, place reinforcing bar cages in the excavated area and the gap between the inner and outer frame walls, and then pour concrete all together. By this,
The steel caisson can be easily installed in a pile without requiring large-scale excavation, and a continuous underground wall can be constructed integrally with the steel caisson without installing wall plates for each element. This paper proposes a construction method that makes it possible to construct underwater structures that are firmly supported.

"Embodiments" Below, embodiments of the present invention shown in the drawings will be described.
As shown in Fig. 1, a trench is excavated on the underwater ground, a steel caisson 2 is sunk in the flooring part 1, and underwater concrete 3 is placed in the flooring part 1, so that the steel caisson 2 is placed under the water. Stabilize the area by solidifying the roots.

The steel caisson 2 is a hollow body that is open at the top and bottom and has double inner and outer frame walls 2a and 2b facing each other with a predetermined gap, and has frame walls 2a at appropriate locations.

A partition plate 4 is provided to partition the space 2b.

Then, on the working yard 5 installed at the -L end of this steel caisson 2 during its manufacture or after it was installed on the bottom of the water,
The skeleton wall 2a is excavated by an excavation machine.

2b is excavated, and a reinforcing bar cage 7 is placed in the gap between the excavated portion 6 and the frame walls 2a and 2b, and then concrete 8 is cast in one piece, and the excavated portion 6 is continuously underground. Build an underwater structural framework surrounded by a series of continuous walls that are integrated into the walls.

To construct this continuous wall, as shown in Figure 7, among the many elements A and B separated by the partition plate 4, every other element A is first constructed, and after that construction is completed, the remaining elements A and B are constructed. Construct every other element B part.

Joint members 9 such as dowel reinforcements are provided in advance on both sides of the partition plate 4 so as to protrude, and the concrete 8 between adjacent elements A and B is integrated as shown in FIG.

When the structural frame constructed in this way is used as an integral structure that does not utilize the internal space of the caisson, for example, as a pier foundation, the inner bottom of the steel caisson 2 is excavated as shown in Fig. Concrete lO is placed in the space and integrated with the continuous wall.

Next, as shown in Fig. 6, when this structural frame is used as a structure that utilizes the internal space of the caisson, such as a ventilation tower for an undersea tunnel, a floor slab integrated with a continuous wall is constructed inside.

When constructing this floor slab, as shown in Fig. 8.9, joint members 11 such as dowel bars are provided protrudingly on the inner and outer surfaces of the floor slab joining portion of the inner frame wall 2b of the steel caisson 2.
A floor slab concrete 13 is placed by wrapping the reinforced reinforcing bars 12 on this, and is integrated with the continuous wall.

In this case, when excavating the underwater ground below between the frame walls 2a and 2b, an excavator such as an excavation packet
A slidable shielding plate 15 is provided in front of the joint member 11 along a guide groove 14 provided in a partition plate 4 so as not to hit the joint member 1, and after completion of excavation, the shielding plate 15 is pulled up and concrete 8 is poured.

"Effects of the Invention" As described above, according to the present invention, a steel caisson consisting of double internal and external frame walls is installed below the water bottom, and after the area under the water bottom is stabilized by hardening, the steel caisson is placed on top of the caisson. By excavating the underwater ground below between the inner and outer building walls, placing reinforcing bar cages in the excavated area and the gap between the inner and outer building walls, and then pouring concrete all together, the large-scale underwater ground can be removed. Concrete is placed between the inner and outer walls of the steel caisson without the need for excavation, and without installing wall plates for each element. We have constructed a continuous wall with high rigidity and precision that is integrated with a continuous underground wall installed in the underwater ground below.This allows us to firmly support the steel caisson on the ground without requiring much construction time or cost. It becomes possible to construct underwater structures with continuous walls.

[Brief explanation of the drawing]

: Figures 51 to 4 are vertical cross-sectional views showing the construction process according to the present invention in order; Figure 5 is a vertical cross-sectional view of an embodiment of a pier foundation constructed according to the present invention; and Figure 6 is a vertical cross-sectional view of an embodiment of an underwater ventilation tower constructed according to the present invention. FIG. 7 is a plan view of the caisson according to the present invention, FIG. 8 is a longitudinal cross-sectional view showing the structure of the joint with the concrete floor slab in the present invention, and FIG. 9 is a cross-sectional view of the caisson according to the invention. FIG. 3 is a cross-sectional view showing the configuration of a connecting portion of an element. 1.Flooring section, 2.Steel caisson, 2a, 2b..Structure wall, 3..Underwater concrete, 4.
・Partition plate, 5. Working yard, 6. Excavation part, 7.
Reinforced cage, 8. Concrete, 9. Joint member,
IO...Concrete, 11...Joint member, 12
...Reinforcing bars, 13.. Floor slab concrete, 14.. Guide grooves, 15.. Shielding plates.

Claims (1)

[Scope of Claims] 1) A steel caisson consisting of double inner and outer frame walls is installed below the water bed, and after the area under the water bed is stabilized by foot-roofing, a steel caisson is installed between the inner and outer frame walls on the caisson. A continuous wall using a steel caisson characterized by excavating the underwater ground below, placing a reinforcing bar cage in the excavated part and the gap between the inner and outer building walls, and then pouring concrete in one piece. Floating construction method. 2) A continuous wall using a steel caisson according to claim 1, wherein after construction of the continuous wall, the continuous wall is integrated by joint members protruding from both sides of a partition plate that partitions each element. 3) After constructing the continuous wall, the underwater ground inside the steel caisson is excavated and concrete is poured inside the steel caisson. Floating construction method for continuous walls using caissons. 4) After constructing the continuous wall, a concrete floor slab is poured inside the steel caisson, and this floor slab is integrated into the continuous wall using joint members protruding from the inner and outer surfaces of the frame wall inside the steel caisson. A method for constructing a continuous wall over water using a steel caisson according to claim 1.