JPH01169021A - Method and device for installing caisson - Google Patents

Abstract

PURPOSE:To make installation accurate by a method wherein water is injected into two base ships connected by a beam at an interval, two wire ropes are fixed to a caisson, the base ships are floated, the caisson is moved to an erection location and water is injected and the caisson is installed. CONSTITUTION:Frames 4 for supporting a beam are disposed in upright onto workboats 1a, 1b respectively, and the beam 6 made of steel is installed through ball joint mechanisms 5, thus constituting one catamaran type workboat. Base ships 1 are shifted to both sides of a caisson 2 temporarily positioned under a water surface, water is injected by a pump 3 and the base ships 1 are sunk, and ropes 7 are engaged with hangers 10 on the top face of the caisson 2. Water is drained by pumps 3 and the base ships 1 are floated, and the base ships are moved up to the erection location 13 of the caisson. Water is injected into the base ships 1 and the base ships are sunk, the bottom of the caisson is grounded, and the ropes 7 are removed and the base ships 1 are detached and shifted. Accordingly, the caisson can be installed accurately in shallow water.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical field The present invention is directed to installing a caisson in a place where the water depth is shallower than the caisson's stuttering water, and where a large ship equipped with a lifting device such as a hoist ship cannot enter. The present invention relates to a method and apparatus capable of installing large caissons without the need for dredging.

(b) Prior art Since it is impossible to use a hoist boat to install a large caisson in a shallow water place as described above, a method to solve this problem is, for example, the method described in JP-A-61-186621. There is technology.

In this method, a plurality of long support rods protruding from both sides of the caisson are installed on the caisson, and floats each having a plurality of supports with metal fittings at the upper end erected on the upper surface are arranged on both sides of the caisson. Both ends of each support rod are supported by metal fittings, and by pouring and draining pallast water into the float, the caisson is lifted, moved, and placed on the bottom of a predetermined mound.

However, this method is extremely difficult to operate because both ends of the caisson support rod must be aligned with the brackets by pouring water into the float while both the caisson and both floats are rocking by the waves and are affected by tidal currents. Not only does this work take time, but when the caisson being supported swings in the waves, an uneven load acts as an impact force on the support fittings of both floats via both ends of the support rod, and the hanging fittings on the caisson are also subjected to impact. It is extremely dangerous.

(c) Disclosure of the Invention The present invention solves the above-mentioned problems by connecting both barges, which serve as floats placed on both sides of the caisson, from the beginning and integrating them using a beam for suspending the caisson. A work boat is used, and the caissons are suspended by wire ropes hanging from the beam.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

(d) Embodiment 1 is a work barge consisting of two barges that serve as floats placed on both sides of a caisson 2. On each barge la and lb, there is a pump 3 for injecting seawater into and out of the boat. is set up. 4
is one beam support frame installed on each barge lJ:.
The frames 4a and 4b of both barges 1a and lb are arranged in parallel so as to face each other, and the frames 4a and 4b are opposed to each other, respectively.
A steel beam 6 is attached to the head via a pole joint mechanism 5.
Both ends of the two-carriage barges 1a and lb are attached to each other and constitute a single twin-hulled work boat connected to the beam 6 of a predetermined length.

At least two wire ropes 7 are vertically disposed at a predetermined interval in the intermediate portion of each of the beams 6 described above. This wire rope 7 is placed on the beam 6 (or on the beam 6) as shown in FIG.
The middle part of the wire rope 7 is suspended and supported by each supporting hardware 8 with a guide groove that can be raised and lowered so that it can be raised and lowered. A socket 9 for pin connection is fixedly attached.

Reference numeral 11 denotes a jack installed on a receiving plate 15 provided in each beam 6. The rod end of the jack 11 is fixed to the lower surface of the support metal fitting 8, and the metal fitting 8 is moved up and down along the guide plate 12. With this, when the caisson 2 is suspended by each wire rope 7, each wire rope 7 is tensioned to equalize the tension (suspension load).

Next, this device moves the caisson 2 into a predetermined mound 1.
3, the installation method will be explained with reference to FIG.

First, one or more caissons 2 are towed directly from land by a crane or by a crane ship, etc. to a temporary storage site 14 located under water at a certain depth of water, and temporarily stored there. Move barge 1 and maneuver so that a predetermined caisson 2 enters between both barges 1a and 1b (third
Figure (a)).

The depth of both barges 1a and lb is based on the depth required to sink the barges 1a and 1b in order to attach the wire rope 7 to the caisson 2, the water depth of the caisson installation location, and the tide level at the time of installation. It is determined by considering the calculated height of the caisson above the water surface, etc.

Further, it is also possible to attach the wire rope 7 to the caisson 2 while floating it as described later, but in this case, the caisson 2 is fixed with an anchor so that it does not move due to the tidal current.

Next, ballast seawater is injected into both barges 1a, 1b by the pump 3, and the wire ropes 7 suspended from each beam 6 are allowed to sink until they become somewhat slack on the surface of the caisson 2. Figure (b)).

Therefore, the socket 9 at the lower end of the wire rope 7 of each beam 6
After tightening the bolts to the corresponding hangers lO on the upper surface of the caisson 2, the sea water is drained from inside the barges 1a and lb, and they are gradually floated to the surface, and each wire rope 7 is tightened (see Figure 3 (H)). )).

At this time, if there is a wire rope whose slack has not been taken up due to a deviation in the position or height of multiple suspenders 10 fitted on the upper surface of the caisson 2 or uneven wire lengths caused by manufacturing errors of the wire rope 7, S,? After the supporting hardware 8 supporting the middle part of the J wire rope is raised somewhat by the jack 11 to remove slack and the tension of each wire rope 7 is equalized, water continues to be drained from inside the barge 1. The caisson 2 is floated to a predetermined height, and in that state is moved to the position of a mound 13 where the caisson 2 is installed.

When the caisson 2 has moved to the predetermined mound 13, seawater is again injected into both barges 1 to gradually sink the barges, and the caisson 2 is gently brought to the bottom on the mound 3. Figure 3 (d)) 7 After caisson 2 hits the bottom, barge 1
After sinking the barge a little to release the tension on each wire rope 7, remove the sockets 9 at both ends of each wire rope 7 from the suspenders 10 of the caisson 2, then drain the ballast water in the barge 1 and float it again. The barge 1 is moved away from the caisson 2 that has been completely installed, and the next caisson installation is carried out again.

(E) Effects of the Invention The present invention is constructed as described above and has the following effects.

a) A large caisson can be easily and accurately installed in a predetermined position without using a lifting machine such as a winch in a place where the water depth of the caisson installation site is shallow and large vessels such as a crane boat cannot enter.

b) Since the caisson is suspended by a wire rope hanging from a beam connecting the left and right barges constituting the work boat, the work of connecting the wire rope to the caisson is easy, and unlike the prior art described above, the caisson is suspended. Unlike the method in which both ends of the support rod are mounted on a caisson and supported by metal fittings on both barges, there is no need for time-consuming connection work due to the influence of waves or currents.

C) Since both barges are connected to multiple beams and integrated, it takes less time to approach both sides of the caisson and shift to the lifting position.

d) Both ends of each beam are connected to the pedestals on both barges via a pole joint mechanism, so each barge can move freely in the horizontal and vertical directions, so the caisson can move freely under the influence of waves. It can always maintain a horizontal state even if an uneven load occurs due to suspension.

e) Each wire rope intermediate support part is equipped with a support hardware that can be raised and lowered to remove the slack in the wire rope when the caisson is suspended, so that each wire rope can hang the caisson with equal tension. The caisson can be lifted and lowered horizontally at all times, etc.

[Brief explanation of the drawing]

Fig. 1 is a front view showing an example of the device of the present invention, Fig. 2 is an enlarged view of the state j3 in which the wire rope is suspended from the beam, and Fig. 3
Figures (A) to (E) are explanatory diagrams showing an example of the work procedure for installing a caisson according to the method of the present invention. Symbol explanation 1 - Two barges 2 - Caisson 3 - Pump 4 - Frame
5-Pole joint mechanism 6-Beam 7-Wire rope 8-Support hardware 9-Socket 10-Hanger 11-Shirt book 12-Guide plate 1
3- Caisson installation on mound 14- Caisson temporary storage area 1
5-Socket plate

Claims (3)

[Claims] (1) Two barges connected to each other by multiple beams at a distance large enough to accommodate the caisson are maneuvered so that they come on either side of the caisson that has been temporarily placed in a temporary storage area or floating on the water surface, and then Seawater is injected into both barges, and both barges are sunk until at least two wire ropes hanging at a predetermined interval from the middle of each beam are slightly slack on the top of the caisson, and then each wire rope is attached to the top of the caisson. After the wire ropes are fixed to the hangers etc. embedded in the barges, each wire rope is tensed while draining the seawater inside both barges, and if there is a wire rope that has not taken up the slack, the supporting hardware supporting the wire rope is raised. After taking up the slack, both barges were floated and moved to the caisson installation site while suspending the caisson with each of the wire ropes mentioned above.Next, seawater was again injected into both barges and both barges were submerged. The caisson installation method is characterized in that after the caisson is brought to the bottom at the installation position by lowering the caisson, each wire rope is removed from the caisson, both barges are floated, and the caisson is separated from the installed caisson. (2) A plurality of pedestals are installed in parallel on each of the two barges that serve as floats, and the opposing pedestal parts of both barges are connected by a beam via a ball joint mechanism to connect the two barges. At least two wire ropes are hung vertically at a predetermined distance from each other in the middle of each beam, and each wire rope has its middle part set on the beam. Connectors that can be attached to hangers attached to the top of the caisson are fixed to both ends of each hanging wire rope supported by supporting hardware, and both barges are each equipped with a pump that pumps water into and out of the ship. A caisson installation device characterized by: (3) Each of the supporting hardware of the wire rope has a substantially semicircular cross section, and the middle part of the wire rope is suspended from the supporting hardware, and each of the supporting hardware is configured to be able to be raised and lowered by a jack installed on the beam. Claim 2
Caisson installation equipment as described in section.