JPS60215924A - Settlement of steel skeleton for underwater foundation structure - Google Patents

Abstract

PURPOSE:To safely set up the steel skeletons of an underwater foundation structure with good accuracy by a method in which skeletons with a bottom are towed to a setting position, a settling device is connected to a guide pile, and the settling device is operated along the guide pile to settle the skeletons. CONSTITUTION:Steel skeletons 1 are moored by chains 20, etc., at a position where the through holes 6 of the skeletons are positioned right above a guide pile 3, and water is charged into the skeletons 1. Whereupon, the projection 10 of a settling device 2 is thrust up to the top of the pile 3, and the device 2 is fixed to the upside of the pile 3. The chain 20 is removed, the coupling of the device 2 and the skeletons 1 is released, and while charging water into the skeletons 1, a winch 11 is operated to settle and set the skeletons 1 on the seabed. The cable 15 is removed out of the skeletons 1, the device 2 is removed out, and the pile 3 is cut down at a given depth under water.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for sinking a steel frame for an underwater substructure. This steel frame, which also serves as formwork, is installed on the head of a pile that has been driven into the waterbed in advance, and is integrated with the pile head using prepacked concrete or underwater concrete using tremie pipes, and is used as the foundation for bridge piers and other underwater structures. becomes.

[Prior art]

Conventionally, when such a steel frame for an underwater substructure was to be sunk to the bottom of the water, the steel frame □ with an open bottom was lifted by a crane ship and then lowered into the water. However, since a large crane ship is required, the cost of the crane ship is high, and there are problems in that the weight of the crane ship is limited by the lifting capacity of the crane ship (currently a maximum of 3500 tons).

[Purpose of the invention]

This invention has a steel frame attached to a garden, floats it, tows it, brings it to the site, and then sinks it using a sinking device attached to a guide table. This enables construction without using a large crane ship, and improves construction efficiency. The aim is to improve construction accuracy and reduce construction costs.

[Structure of the invention]

In the method for sinking a steel frame for an underwater substructure according to the present invention, the work is carried out in the following steps.

(1) Drive piles into the water bottom. Use a suitable number of these as guide stakes and raise them just below the water surface.

(2) A steel frame for underwater substructures will be floated with a bottom and towed to the installation location. This steel frame is pre-prepared with through holes that correspond to the guide pile positions.
At this through-hole position, a hanging material with a winch width or a submersion device having a hanging device is temporarily fixed.

(3) Water is poured into the steel frame on the guide desk or ballast material is put into the steel frame to lower the stifling water of the steel frame, and the sinking device is connected to the guide pile at the through hole position.

(4) With the submergence device connected to the guide table, the steel frame and the submersion device are separated, and the weight of the steel frame is supported by the guide piles via the hanging material.

(6) Gradually lower the steel frame onto the water bottom by operating the winch of the lowering equipment. The guide pile is then cut to a predetermined depth.

〔Example〕

The illustrated embodiment will be described below.

As shown in FIG. 8, the steel frame 1 that also serves as a formwork has a bottom 4, a cylinder 5 that accommodates the pile head when installed on the seabed surface, and a through hole that accommodates the guide pile 3 when submerged. A hole 6 is provided. The cylinder body 5 has an upper lid 7 attached thereto. The top of the through hole 6 shall be higher than the top of the edge of the steel frame 1. Frame 1
After installing the pile on the seabed surface, there is a core machine that fills the space between the cylinder 5 and the pile cap with a filler such as concrete in order to connect the pile cap and the frame 1. To make this possible, the top cover 7 is placed underwater. Additional bolts are attached to the cylindrical body 5 so that it can be removed. As shown in FIG. 9, pulp 17, 1
After the frame 1 is installed, the filling material can be injected from the pulp 17 while the pulp 18 is left open. In this case, the top cover 7 may be welded to the cylindrical body. Note that 8 in the figure is an internal support structure.

As shown in FIG.
Cylindrical projection 10 located at the bottom of. Winch 11 on column 9. It consists of a bracket 1 etc. attached to the column 9 @ surface of the pulley n1. The diameter of the column 9 is slightly smaller than the through hole 6 of the frame 1, and the diameter of the cylindrical projection 10 is slightly smaller than the inner diameter of the guide pile 3.

To attach the submersion device 2 to the steel frame 1, the submersion device 2 is installed in the through hole 6 of the frame 1 in advance.

It is preferable to attach it using bolts 14 so that it can be easily removed. The shape when installed is as shown in Figure 11. At this time, the lower end of the cylindrical protrusion 10 of the sinking device 2 is made to be slightly higher than the lower end of the steel frame 1. Next, the cable 15 of the winch 11 is connected to the locking portion 16 of the frame 1 via the pulley ν.

As shown in Figure 1, the required number of piles are driven in advance at the installation location of the steel frame 1. Some of these piles will be used as guide piles 3 during sinking, so they will be placed just below the water surface. Let it stand up until. The top level of the guide pile 3 is the steel frame 1
The position should be slightly lower than the stuttering depth when floating.

As shown in Figure @2, the steel frame 1 is floated and towed to the installation location with the submersion device 2 added to the through hole 6. At this time, there may be cases where sufficient buoyancy cannot be obtained due to the relationship between the body weight and the height of the body footing, and floating towing is impossible. Floating towing is possible by raising the steel @19 on the outer periphery of the footing.

5 to 7 show the state of the installation, and the steel frame 1 is towed to the installation location and is moored by chains or the like at a position where the through hole 6 is directly above the guide pile 3. Thereafter, by pouring water into one circle of the structure, the water in the structure 1 is reduced, and as shown in FIG.
is inserted into the top of the guide pile 3, and the sinking device 2 is fixed on the guide pile 3.

In this state, remove the mooring chain, and if a float is used, remove the float.

Next, by removing the bolts 14 connecting the submersion equipment 2 and the steel frame 1, and further injecting water into the frame 1, the weight of the frame is reduced by the cable 15, winch 11. It will be supported by the guide pile 3 via the pillar body 9. In this state, the steel frame 1 is submerged by operating the winch 11 while pouring water into each circle of the steel frame. After the footing part of the body 1 is submerged under the water surface, the body 1 can be installed on the seabed only by operating the winch 11. Instead of pouring water into each frame, ballast material such as aggregate may be added.

Thereafter, the cable 15 is removed from the steel frame 1 on the seabed surface, the sinking device 2 is removed, and the guide pile 3 is cut underwater at a predetermined depth, thereby completing the sinking.

〔Effect of the invention〕

The steel frame is equipped with a bottom, floated, and towed to the installation location.
The submersion equipment and guide pile are connected using a through hole, and the submergence is gradually carried out along the guide pile by operating the winch of the submersion equipment, which is economical and does not require a large crane ship. Not only can it be constructed, but the combination of guide piles and sinking equipment allows for accurate and safe construction.

In addition, since the floated and towed objects are gradually submerged,
There are no restrictions on the weight of the steel frame, making it possible to construct very large-scale underwater foundations.

[Brief explanation of the drawing]

Figures 1 to 7 are front views showing the outline of the construction procedure of this invention, Figure 8 is a partial vertical cross-sectional view of the steel frame used in this invention, and Figure 9 is a modification of the pile cap cylindrical part. Fig. 10 is a front view showing an example of the submersion equipment, Fig. 11 is a longitudinal sectional view showing how the submergence equipment is attached to the steel frame, and Fig. 12 is the connection between the submergence equipment and the guide pile. It is a longitudinal cross-sectional view showing a state. 1...Steel frame 2...Sinking device 3.
...Guide stake 4...Bottom 5...
Cylindrical body 6...Through hole 7...Cylinder top cover
8... Internal support structure 9... Column 10
......Cylindrical projection 11...Winch 1
2... Pulley 13... Bracket 14
...Poldor...Cable 16...
...Locking part 17...Pulp 18...
・Pulp 19...Steel @ 20...Mooring chain Fig. 1 Fig. 2 Fig. 6 Fig. 2 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 11 Fig. 12 Fig. 1 Continuing from page 1 @ Inventor Hiroshi Kobayashi - Meiichi Nishinaga Technology Research Unit H Hondori 1-3 1-3 Sumitomo Metal Industries, Ltd. Junior High School 1

Claims (1)

[Claims] (1) A steel frame for underwater substructures having a bottom and through-holes is floated and towed to the installation position, and water is poured into the frame or ballast material is poured into the frame on a guide table installed in advance on the bottom of the water to prevent flooding. After lowering and connecting the submersion device with a hanging material temporarily fixed at the through-hole position of the structure to the guide pile, the submergence device is separated from the steel structure on the guide table, and the weight of the structure is measured through the hanging material of the submersion device. A method for sinking a steel frame for an underwater substructure, in which the frame is gradually lowered to the bottom of the water by operating a sinking device while supporting it with guide piles.