JPH0366834A - Construction method for caisson etc. - Google Patents

Abstract

PURPOSE:To provide a place for erecting a large caisson easily by furnishing a floater, which rises and falls from a fame constructed over the sea and which is capable of pouring/exhausting the water and of pressurizing, erecting the caisson from its bottom to the top step by step, and performing floating-up and carrying-out after the completion. CONSTITUTION:A steel pipe pile 1 for receiving a frame is driven in the ground B under the water, and thereon a floater 8 which rises and falls from frame 2 and is capable of pouring/exhausting water and of pressurizing, is installed, wherein a hydraulic jack 5 and a gate-type mobile crane 3 are installed on the frame 2. Then this floater 8 is put afloat on the water to provide a space for erecting a large caisson, which is erected from the bottom to the top step by step through utilization of the buoyancy of floater 8. After completion of erecting the caisson, the water is exhausted from it and associate objects to accomplish floating-up. Meantime the floater 8 is subjected to pouring of water and pressurization, and the caisson is carried out of the floater 8 and towed to a specified place. Thereby the erecting place for caisson can be secured easily on the sea.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a construction method for caissons and the like used for constructing undersea tunnels, artificial island seawalls, and the like.

[Conventional technology]

Conventionally, the construction method of caissons etc. that has been commonly used is
A wide caisson construction yard is set up on the quay, etc., and construction is carried out on that yard.When constructing the caisson on the yard, it is necessary to erect high work scaffolds along the progress of the work, and it is also difficult to transport the caisson after construction is completed. In this case, equipment that can berth a large crane ship and hoist and lift a caisson is required.

In addition, caissons are currently being constructed for dry docks and floating docks.

On the other hand, in recent years it has become extremely difficult to secure large construction spaces on quays, etc., and there are many types of dry docks, floating docks, etc., varying in size and small, and they are limited in scale and quantity.At the same time, construction work has become larger. As a result, the size of caisson manufacturing has progressed, making it difficult to handle this with the quay caisson construction yards, dry docks, floating docks, etc. that are currently in use, and the method of transporting completed caissons has also increased in size, requiring large cranes. At present, there are issues with securing the procurement of ships, lifting capacity, safety, and economic efficiency.

[Problem to be solved by the invention]

The present invention was made in order to solve the above-mentioned conventional problems, and it is possible to secure a place for building a caisson, etc., and to establish safety and economy in the construction work, lifting, carrying out, and transportation of the caisson body. The problem to be solved was to provide a construction method for measuring caissons, etc.

[Means to solve the problem]

As a means to solve the above-mentioned problems, the construction method of the caisson etc. of the present invention is a method for constructing a caisson, etc., in which a water sluice is provided that can be raised and lowered by a winch or jack from a frame such as a laminated structure fixed on the water near the coast. On top of the floater, which can be pressurized, caisson etc. are installed step by step from the caisson base at the bottom to the top, including reinforcing steel assembly, formwork assembly, concrete pouring, concrete curing and formwork dismantling (caisson base formwork Construction will be carried out through a series of steps (in order to shorten the process by assembling the reinforcing bars on the ground and installing them on the floater using a concave crane).

During the above construction, water is poured into the caisson, etc. one after another, and the construction site is always kept at a constant height to ensure that the construction work is carried out safely and smoothly.After the construction of the caisson, etc. is completed, It is characterized in that it is floated by draining water, and on the other hand, it is carried out from the floater and towed to a predetermined position by pouring water into the floater and pressurizing it.

Here, a floater that can be filled and pressurized can reduce the weight of the caisson etc. due to its buoyancy, and by pressurizing the inside of the floater, there is no problem with the strength of the floater even if it goes deep underwater. .

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of caisson construction according to the caisson construction method of the present invention will be described below with reference to the drawings.

First, the embodiment shown in the front view of FIG. 1 and the side view of FIG. 2 is an example of building a large caisson used at sea.
On the sea near the quay 23 at the seawall level GL, a steel pipe pile 1 for use as a pedestal is driven, and a hydraulic jack pedestal etc. Assembled, hydraulic jack 5, gate type lane 3, hoist crane 4, portable work scaffold 6
, a front-back sliding work scaffold 7 is installed.

As mentioned above, the floater can be raised and lowered freely from the mount 2 fixed on the sea surface indicated by the high tide water level HWL and the standard water level WL via the hydraulic jack 5, the floater suspension chain 14, and the floater suspension bin 13 along the floater elevation guide rollers 9. A floater 8 is provided. This floater 8 includes an automatic opening/closing water supply port 10, a drain pump 11, a water inlet 12, a drain port 24,
Since it is provided with a pressurizing port 26 and the like, it is possible to pour in water and pressurize the inside thereof.

Next, the floater 8 is floated on the water, the hydraulic jack 5 and the floater suspension chain 14 are fixed with the floater suspension pin 13 as shown in the hydraulic system diagram in FIG. etc., the weight
The hydraulic jack 5 is actuated automatically by the level monitor 17 and the control device 18, etc., or manually, and the floater 8 is raised and lowered to a certain level, i.e., on a portable work scaffold 6 for work, or on a front-back sliding work scaffold 7. On the level, floater 8
I try to keep it.

In addition, in FIG. 7, 35 is a flow meter, 16 is a hydraulic unit pump, and the automatic control system for the floater 8 shown in this hydraulic system diagram is a flow meter.
When performing vertical movement, the vertical movement of the floater 8 is displayed in unit units on the weight level monitor 17, and the vertical position of the floater 8 is moved according to the plan based on the vertical movement of the floater 8 by manual or program control. This embodiment is composed of a movement amount monitoring device, a load meter with a built-in automatic control function, a jack operation monitoring panel, etc.

Next, the above-mentioned caisson construction equipment is installed on the sea, and a load sensor 15 for automatic control of the hydraulic jack 5 is attached to the floater 8, and while the top of the floater 8 is used as a space for caisson construction, the buoyancy of the floater 8 is A large caisson is built in stages from the bottom to the top using

That is, as the caisson construction work progresses step by step, the increasing weight of the caisson body, a certain amount of buoyancy of the floater 8 body, and the lifting force of the hydraulic jack 5 for raising and lowering the floater are measured on the weight level monitor 17. Automatically controlled, maintaining a certain level, and always at a constant height, various work scaffolds 6°7 are used to assemble reinforcing bars for caisson construction, concrete formwork assembly, concrete pouring, concrete curing, concrete formwork dismantling, etc. This makes it easy to perform a series of construction tasks.

In addition, as the caisson construction work progresses, the weight of the caisson itself increases and it sinks.At the same time, the load sensor 15 of the hydraulic jack 5 senses the load at the limit where the caisson's buoyancy occurs, and the weight level monitor 17 is activated. seawater is automatically injected into the caisson body, the balance between buoyancy and sinking force is controlled, and the caisson body is always maintained at a certain work scaffolding level, allowing a series of caisson construction operations to be carried out in a gate-like manner. As the construction progresses, there is no need to add or add more scaffolding than usual, and at the same time, work at heights is significantly reduced, resulting in highly economical and safe work.

Additionally, since water is injected into the caisson itself during construction work and the caisson body is allowed to sink into the sea, the poured concrete can be cured underwater at the same time, shortening the curing period.
Furthermore, after the caisson construction is completed, the seawater inside the caisson body can be drained and the caisson body can be made to float.

Further, when carrying out the caisson main body, the caisson main body can be easily carried out and towed directly to the destination by the tugboat 22 without using a large crane ship.

Next, a construction procedure using the method for constructing a caisson or the like according to the present invention described above will be explained based on the drawings.

First, as shown in Fig. 1, after installing the floater 8 and the front and back sliding work scaffold 7 for caisson construction, as shown in Fig. 3, the formwork and reinforcing bars of the caisson base 19 were assembled on the ground, and the gate-shaped Install it on the floater 8 with a crane,
Place concrete. Next, the scaffold hanging hanger 27
The portable work scaffold 6 is installed.

Next, as shown in Fig. 4, the first stage of construction of the caisson body involves assembling its reinforcing bars, assembling the concrete formwork 20, pouring concrete using the ready-mix mixer 21 connected to the ready-mix concrete pump, concrete curing, and concrete A series of construction work consisting of dismantling the formwork is performed, and the concrete formwork 20 is assembled and used on land using a portal crane. In addition, the process of dismantling the formwork is also shortened by taking it apart in large pieces.

During this time, water is poured into the caisson body as shown by arrow W to balance the buoyancy and cure the underwater concrete. Then repeat the above steps step by step.

After the caisson construction is completed, the portable work scaffold 6
The caisson is dismantled using a scaffold hanging hanger 27, and the seawater inside the caisson body is drained using a pump 29 as shown by arrow W as shown in FIG.

Next, the caisson is moored in a floating state, and there,
Water is poured into the floater 8 to cause the floater 8 to settle. Note that by pressurizing the inside of the floater 8, there is no problem in terms of strength even if the floater goes deep into the water.

Then, as shown in FIG. 6, the caisson main body 30 after completion of construction is carried out from the caisson construction yard and towed by the tugboat 22.

Therefore, the seawater in the floater 8 is drained and the floater 8 is jacked up to float.

By repeating the above series of operations, a large number of caissons can be constructed.

〔Effect of the invention〕

As explained above, according to the caisson construction method of the present invention, a floater having the function of a barge for caisson construction is floated on the sea where the caisson is constructed, and a hydraulic jack for raising and lowering the floater, a gate type running By providing lanes for carrying out construction work and a platform equipped with scaffolding for caisson construction,
A site for building a caisson can be easily secured on the sea, eliminating the need for a yard for building a caisson on land, a dry dock, and a floating dock.

In addition, since the caisson is built on a floater, the caisson itself can be floated and towed easily to the construction site using a tugboat without using a large crane ship when transporting the caisson body after construction is completed, making it more economical. This has the effect of ensuring safety and security.

On the other hand, even in caisson construction work, if the buoyancy of the floater and the lifting force of the hydraulic jack for raising and lowering the floater are detected by the load sensor of the hydraulic jack, and the hydraulic jack is automatically controlled by the operation of the weight level monitor, it is possible to always maintain a constant level. Since the floater can be held at a certain height, a series of operations can be carried out using a work scaffold at a certain height.As a result, work at heights is significantly reduced, and there is no need to add work scaffolds, which is both economical and safe. It also has the advantage of being secure.

Furthermore, as the caisson body is being constructed, the caisson body is lowered into the sea in order to secure a working scaffold at a certain height, so the concrete can be cured underwater at the same time, resulting in a significant reduction in the curing period, which is economical. At the same time, it has the advantage that process control can be easily performed.

[Brief explanation of drawings]

Figure 1 is an overall front view of the device used in the caisson construction method of the present invention, Figure 2 is a side view of Figure 1, and Figures 3 to 5 show the construction of the equipment shown in Figure 1. A series of overall front views explaining the work procedure for building a caisson in stages, Figure 6 is a plan view showing the towed state of the built caisson body after completion, and Figure 7 is the lifting hydraulic pressure of the floater in Figure 1. It is a system diagram. 2...Hydraulic jack mount, 5...Hydraulic jack, 8
...Floater, 10...Automatic opening/closing water supply port, 11...
- Drain pump, 12... Water inlet, 24... Drain port.

Claims (1)

[Claims] When constructing a caisson, etc. in stages from the bottom to the top on a floater that is movable up and down on a pedestal fixed on the water and capable of pouring water and pressurizing, water is poured into the caisson, etc. and the floater as appropriate. A construction method for caissons, etc., in which the caissons, etc., are always maintained at a constant height while pressurizing, and after the construction of the caisson, etc. is completed, the caisson, etc. is drained, floated, and carried out from above the floater.