JPS604328B2 - Cell submersion method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a construction method for constructing large-diameter prefabricated cells constituting seawalls, quay walls, embankments, etc.

Large flea cells are difficult to sink.

In other words, excavating the entire submerged area requires a large amount of excavation, and backfilling is not easy. And the cell is Tonosho,
Special measures must be taken to withstand water pressure. Therefore, methods such as using a large number of driving machines or dividing the cell vertically into a plurality of parts and driving each one in sequence have been implemented. Furthermore, when the seabed's ground is soft, there are various problems such as the need to replace the soft layer with a high-quality layer and sink the caisson cell. This invention was developed to address the above-mentioned conventional problems, and will be explained below with reference to the illustrated embodiments.

Cell A is usually in the shape of a corrugated pipe with a diameter of 1 to 8 h, but may have a larger diameter or may be a steel plate cell.

A support beam 1 is spanned across the edge of this cell A, and by being attached to the support beam 1, a central drive device 2 consisting of a main rotating motor is fixedly arranged at the center of the upper part of the cell. A beam 3 is attached horizontally and radially to the cell, and a peripheral drive device 4 consisting of a motor is provided at the tip of the beam 3, and has a long rotating shaft protruding from the peripheral drive device from the lower end of the cell. Excavator 5 rotating at high speed
has been installed. The excavator 5 is provided with a bit 7, preferably a wing-spreading bit, at the tip of a rod 6, and a large number of removable fly wings or protrusions 8 protrude from the middle portion of the rod 6. Further, the rod 6 is hollow so that water and air can be ejected, and mortar or chemical solution can be injected.
During construction, cell A, in which the excavator 5, central drive device 2, peripheral drive device 4, etc. are arranged, is installed on soft ground C using a crane ship B, etc., and the central drive device 2 is activated to move the beam 3. By rotating the excavator 5, the excavator 5 is rotated in a continental circle at a low speed, and the peripheral drive device 4 is activated to rotate the excavator 5 at a high speed, thereby leaving the ground inside the cell below the inner wall of the cell A. The ground is excavated in a circular manner, and cell A is deposited in the excavated trench along with the excavation.

Of the soil excavated at this time, the coarse particles and sandy parts are carried out by an excavator, and the silty parts are mixed with muddy water by the rod 6 and the protrusions that are thrust into it, and as the rod 6 advances. The muddy water and silt deposits are sent to the resulting site to prevent the collapse of earth and sand into the site, and also to avoid large bending moments occurring in the rods 6.

If the ground is hard or if the supporting layer is reached, high pressure water can be ejected from the rod 6 to excavate the ground. When the cell A reaches the supporting ground layer D at a predetermined depth, mortar or chemical solution is injected through the rod 6 to fix the bottom of the cell A, and then the excavator 5, each driving device 2, 4, etc. are removed, and if necessary, Cell A by backfilling the annular groove in Cell A
Complete the installation of The above-mentioned construction is repeated one after another, cells A are successively deposited, and a bank protection etc. is constructed. In the figure, E indicates a solidified block of cell A in water. This invention has the above-mentioned configuration, and when sinking a prefabricated cell, the soft ground is not excavated across the entire cross section of the cell, but the ground beneath the cell wall is excavated in a circular pattern, leaving the ground inside the cell, which improves construction efficiency. good. In addition, since it can penetrate through soft ground and reach the supporting ground directly, there is no need to replace soft workers with quality workers, and there is less seawater pollution during construction. In addition, since the excavator is equipped with a light frame wing and the muddy water construction method is applied, collapse of the excavated trench can be prevented and the bending force caused by the rod can be reduced. Further, the reaction force of the excavator can be applied to the cell via the support beam. Furthermore, by rotating the excavator at high speed and slowing down the rotation of the excavator in its great circular revolution, the torque of the motor in the central drive device is reduced, making it possible to prevent large bending of the rod.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an outline of an embodiment of the present invention, and FIG. 2 is a plan view of a cell, an excavator, etc. A... Cell, B... Crane ship, C... Soft ground, D... Supporting ground layer, E... Foundation block, 1...
・Support beam, 2... Central drive device, 3... Beam, 4...
- Drive device, 5... Excavator, 6... Rod, 7... Bit, 8... Fly wing or protrusion. Figure 2 Figure 1

Claims (1)

[Claims] 1 An excavation system in which a beam is provided radially protruding from a central drive device fixed to a support beam at the center of the top of the cell, and a peripheral drive device is provided at the tip of the beam, and a long rotation axis is provided from the peripheral drive device to the bottom end of the cell. a central drive device rotates the excavator in a large diameter circle along the inner wall of the cell at low speed, and a peripheral drive device rotates the excavator at high speed;
A cell sinking method characterized by excavating the ground below the cell wall in a circular manner while leaving the ground inside the cell, and sinking the cell into the circular excavation trench along with the excavation.