JPS61191726A - Underwater concrete placer - Google Patents

Abstract

PURPOSE:To lessen the intrusion of water into concrete supply tube and the contact of water with concrete by providing a foldable film, a weight, a tube, and a skirt in order on the lower end of the concrete supply tube of a placer. CONSTITUTION:A placer 10 is lowered under water, and when a screen 6 on the lower end of a supply tube 12 reaches a place 17 where concrete is to be placed, a film 18 is folded. Compressed air is supplied into the tube 20 to expand it 20, whereupon a weight 42 and the periphery 18b of the film 18 are expanded while contacting with the place 17 to prevent the intrusion of water between the film 18 and the place 17. Concrete C is supplied through the supply tube 16 and placed into the space formed by the film 18, the tube 20, and skirt 40. The separation of the tube 20 from the place 17 can thus be prevented by the weight 42 and the concrete C can be placed without exposed to external water.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an apparatus for placing concrete underwater.

(Prior Art) As a device for pouring concrete underwater, there is a tremie pipe having a funnel-shaped upper end and an open lower end. Concrete is placed at a predetermined location underwater by pouring it into the funnel-shaped upper end located above the water surface and discharging it from the lower end located underwater.

By the way, the concrete poured into the tremie pipe is
In order to prevent separation due to water entering the tremie tube, conventionally, a tremie tube has been used which is equipped with a plug using a sponge or a plunger that is pulled out from the lower end of the tremie tube as the amount of concrete input increases.

This tremie pipe can prevent concrete from separating inside the pipe. However, this tremie pipe has the disadvantage that the concrete ejected from its lower end is exposed to surrounding water until it reaches the pouring surface, causing the concrete to deteriorate.

(Objective) The object of the present invention is not only to prevent water from entering the concrete supply pipe, but also to minimize contact between concrete and water during pouring.

(Configuration) The underwater concrete placement device according to the present invention basically has the following features:
A concrete supply pipe whose one end is connected to a concrete supply means and whose other end is provided with a check valve that allows concrete to be discharged; a membrane that is attached to the surface and can come into contact with the surface where the concrete is to be poured;
a tube disposed around the outer periphery of the membrane and capable of being inflated and deflated; means for pumping fluid into the tube to expand the membrane; and a weight surrounding the membrane and attached to the membrane or the tube. It is characterized by having the following.

Further, the present invention is characterized in that a first sliding member is attached to the concrete supply pipe in a fluid-tight manner and movable in the longitudinal direction thereof, and an inner peripheral portion of the membrane is attached to the first sliding member. Liquid-tightly joined to the component.

Furthermore, the present invention includes a second sliding member attached to the concrete supply pipe so as to be movable in the longitudinal direction thereof, and a support member connected to the second sliding member and the outer periphery of the membrane or the tube. It is characterized by having the following.

(Operations and Effects) According to the device according to the present invention, after the concrete supply pipe is lowered underwater until the other end reaches above the planned pouring surface in the water, fluid is forced into the tube to expand the tube. Then, concrete is placed in a space surrounded by the planned pouring surface and the tube and membrane that are in contact with the surface.

During the descent of the concrete supply pipe, a check valve prevents water from entering the concrete supply pipe, and the membrane surrounding the concrete supply pipe and the tube without fluid injection are maintained in a hanging state by a weight. . The membrane reaches the intended pouring surface while being folded sequentially from its outer circumference to its inner circumference. Furthermore, when the tube is expanded, the outer peripheral portions of the tube and membrane expand while contacting the surface to be cast due to the action of the weight. For these reasons, the amount of water that intrudes into the space surrounded by the planned pouring surface and the tube and membrane is extremely small, and therefore, the concrete placed in this space is free from separation due to contact with water. Deterioration etc. can be minimized.

After pouring concrete in the space surrounded by the membrane and the tube, the first sliding member is raised to stop the inner peripheral part of the membrane at an upper position, so that the concrete can be placed between the tube and the concrete pouring surface. A gap can be provided between the two. If more concrete is supplied while maintaining this state, the concrete will flow out from the gap, so
It is possible to place waste concrete over a wider area.

Furthermore, after pouring concrete in the space surrounded by the membrane and tube, and before lifting the device,
By raising the second sliding member, the tube and membrane can be smoothly peeled off from the poured concrete.

(Embodiments) The features of the present invention will become clearer from the following description of the illustrated embodiments.

As shown in FIGS. 1 and 2, the underwater concrete placing apparatus 10 according to the present invention has one end 12a connected to a concrete supply means (not shown) such as a concrete pump, and the other end 12b connected to a concrete supply means (not shown) such as a concrete pump. A concrete supply pipe (hereinafter simply referred to as supply pipe) 12 is provided with a check valve 14 that allows concrete to be discharged from the end.

The present device 10 can be suspended by a hanging rope (not shown) extending from a floating body (not shown) such as a barge floating on water, or by being suspended by a swinging arm (not shown) disposed on the floating body. Alternatively, a hose (not shown) connected to the supply pipe 12 and a concrete pump (not shown) constituting the concrete supply means described later, which is arranged on the floating body. ) is held underwater through.

For example, the check valve 14 is connected to the other end of the supply pipe, that is, the lower end 12.
b can be constituted by a pair of half-moon-shaped valve bodies that are swingable around an axis extending in the transverse direction. Each valve body is connected to the concrete from one end of the supply pipe, that is, from the upper end 12a to the lower end 12b.
The supply pipe 12 swings so as to flow only toward the supply pipe 12, and is surrounded by a sealing material (not shown) made of an elastic material to prevent water from entering the supply pipe 12 in the closed state.

It is desirable to connect a cylindrical screen 16 having a lattice pattern concentrically to the lower end 12b of the supply pipe.

When concrete is placed underwater, the screen 16 comes into contact with the concrete placement surface 17 (see Figures 3a to 3e), and the lower end 12b of the supply pipe defining the concrete discharge port is placed on the concrete placement surface 17 (see Figures 3a to 3e). Located above surface 17.

Around the supply pipe 12, there is a membrane 18 that has an inner peripheral part 18a surrounding it and can come into contact with the intended pouring surface 17, and a tube 20 that can be expanded and contracted provided on the outer peripheral part 18b of the membrane. and are arranged. The membrane 18 and tube 20 are made of cloth, polymeric materials (rubber, vinyl chloride, polyethylene,
Each is made of a material that allows free deformation, such as polypropylene.

The inner circumferential portion 18a of the membrane has an annular first sliding member 2 fitted to the supply pipe 12 in a fluid-tight manner and movable in the longitudinal direction thereof.
2 to the supply pipe 12. The inner peripheral part 18a of the membrane is liquid-tightly joined to the first sliding member 22, and by moving the first sliding member 22 up and down, the height position of the inner peripheral part 18a of the membrane can be changed. I can do it.

The inner circumference 1 of the membrane without using the first sliding member 22
8a can also be attached directly to the supply pipe 12 in a liquid-tight manner. However, in order to enable the membrane 18 to come into contact with the surface 17 to be poured during concrete pouring, more specifically, the outer circumferential portion 18b or the outer circumferential portion 18a and the inner circumferential portion 18 are connected from the outer circumferential portion to the outer circumferential portion 18a.
The inner circumferential portion 18 is arranged so that the membrane portion between the inner circumferential portion a and
The mounting position of a is determined.

A first sliding member 22 that fits into the supply pipe 12 is arranged parallel to the supply pipe 2 and can be moved up and down by a hydraulic cylinder 24 . The hydraulic cylinder 24 has both ends
A bracket) 26a fixed to the first sliding member 22 and a bracket) 2 fixed to the supply pipe 12 at an upward distance.
6b.

The illustrated membrane 18 and tube 20 have a circular planar shape when expanded (see FIG. 2), and the membrane 18 as a whole has an inverted bowl-like shape. The gta and tube 20 can be formed to have a polygonal planar shape.

A plurality of ears 28 are attached to the outer peripheral portion 18b of the membrane at intervals in the circumferential direction, and each ear side 28 and the supply pipe 12 are connected via a support member 30 made of a cable. The support member 30 may be constructed of a rigid body such as a pivotably connected rod instead of the cable.

One end 30a of each support member is connected to a second sliding member 32 which is located above the first sliding member 22 and is attached to the supply pipe 12 so as to be movable in the longitudinal direction thereof, and the other end 30b is connected to the ear side. 28. By moving the second sliding member 32, the height position of the tube 20 can be changed.

The second sliding member 32 that fits into the supply pipe 12
It can be moved up and down by a hydraulic cylinder 34 arranged parallel to 2. The hydraulic cylinder 34 has both ends,
A bracket 36a fixed to the second sliding member 32 and the supply pipe 1 between the first and second sliding members 22,32.
It is pivotally connected to a bracket 36b fixed to 2.

The tube 20 is expanded by pumping a gas such as air or a liquid such as water or oil into its interior via the pumping means 38, and is contracted by stopping the supply of the gas or liquid. The tube 20 can be freely deformed during contraction. The tube pumping means 38 consists of a hose 38a communicating with the tube 20 and a supply source (not shown) of pressurized air or pressurized liquid disposed on the floating body.

The membrane 18 and the tube 20 can be formed integrally instead of the illustrated example in which each is constructed separately and then joined together. Further, in order to improve the adhesion of the tube 20 to the expected pouring surface 17, it is desirable to provide the tube with a skirt 40.
It extends along the tube 20 on the side of the membrane outer periphery 18b opposite the joint. The tube 20 and the skirt 40 can be constructed separately and joined together, or can be integrally formed as in the example shown in one figure. Scar) 40
is made of a flexible material such as the polymer material so as to fit well with the planned pouring surface 17, and is formed with a plurality of pleats to increase elasticity in the circumferential direction. is desirable.

The zero weight 42 in which a chain-shaped weight 42 is arranged surrounding the membrane 18 is a chain-shaped zero weight 42 that is attached to the membrane 18 or the tube 20 at a plurality of locations at intervals in the circumferential direction. Therefore, one weight 42 is the tube 20
It can be deformed according to the expansion and contraction of .

Figures 3a to 3e show the process of placing concrete in water using the present apparatus IO.

First, as shown in Figures 3 and 3, the device 10 is lowered in the vertical direction toward the intended pouring surface 17 in the water. Prior to this lowering, the height of the first sliding member 22 is adjusted so that the scarf 40 can come into contact with the planned pouring surface 17 (see Fig. 3d). During the descent, the membrane 18 and the tube 20 to which no fluid has been injected hang down due to the weight of the weight 42 loaded thereon.

When the screen 16 attached to the lower end of the supply pipe 12 comes into contact with the planned pouring surface 17, the skirt 40 and tube 20, together with the weight 4z, surround the screen 16 and come into contact with the planned pouring surface 17, and the inside thereof In M2
The portion from the outer periphery to the inner periphery of S contacts the expected pouring surface 17 in a folded state. In this way, the planned pouring surface 1
A space shielded from the outside world is defined by the skirt 40, tube 20, and membrane 18 in contact with 7 (Figure 3b)
.

Furthermore, during the descent and after reaching the intended pouring surface 17, the lower end 12b of the supply pipe is closed by the check valve 14 (FIG. 1), so that no water enters the supply pipe Iz.

Next, as shown in FIG. 3c, by supplying pressurized air or liquid into the tube 20 via the pressure feeding means 38,
Expand tube 20. As the tube 20 expands, the weight 42 and the outer peripheral portion 18b of the membrane are expanded while being in contact with the expected casting surface 17. Therefore, almost no water from the outside world enters between the membrane 18 and the pouring surface 17.

After the expansion is completed, concrete C is discharged into the space. The expanded tube 20 does not move away from the planned pouring surface 17 because the vertical load from the weight 42 is acting on it, and therefore, the concrete C is poured without being exposed to water in the outside world. . As the discharge amount of concrete C increases, the membrane 18 and the tube 20 are placed on the planned pouring surface 1.
7, the volume of the space increases. Concrete C is supplied until membrane 18 assumes the shape of an inverted bowl.

[When 1g has the bowl shape, the skirt 40
Since the weight of the zero weight 42 whose peripheral edge is in contact with the planned pouring surface 17 is transmitted to the skirt 40 via the tube 20, the skirt 40 does not separate from the planned pouring surface 17.

After the concrete has been placed in this manner, the supply pipe 12 is raised (FIG. 3e), by raising the second sliding member 32 at the same time or before the raising of the tube 20 and ! 118.

Sequentially, it can be pulled away from the poured layered concrete. To explain the operation of the tube 20 at this time, the tube 20 rotates around its center line 20a (see FIG. 1) as the tube 20 moves up for the second time. At this time, the outer circumference 18b of the membrane is rolled into the tube 20, while the tube rotates and moves linearly upward (see the imaginary line in FIG. 1). Therefore, the membrane 18 and the tube Damage to the concrete layer during pull-off of 20 is prevented.

Note that if the sliding member 32 of l'12 is not provided or not used, the tube 20 can be flattened by stopping the pressure feeding of the fluid to the tube 20, and the supply pipe 12 can be pulled up. . At this time, since a frictional force acts between the flat tube 20 and the concrete layer, the concrete layer may be damaged.

Further, from the state shown in FIG. 3d in which a predetermined amount of concrete has been supplied, the first sliding member 22 is slightly raised to create a gap between the skirt 40 and the planned pouring surface 17, and to supply concrete. As the process continues, concrete overflows from the gap and spreads around the tube 20, as shown in FIG. This is suitable for placing sacrificial concrete.

[Brief explanation of drawings]

FIGS. 1 and 2 are a half-longitudinal sectional view and a plan sectional view of an underwater concrete placing device according to the present invention, and FIGS. 3a and 3b.
Figures 3C, 3D, and 3E are schematic process diagrams of underwater concrete placement using this device, and Figure 4 is a schematic diagram showing how the device is used during dumping concrete. FIG. 10: Underwater concrete placement equipment. 12: Concrete supply pipe, 14: Check valve, 17: Planned pouring surface, 18: Membrane, 18a, 18b: Inner peripheral part and outer peripheral part of membrane, 20: Tube. 22, 32: first and second sliding members, 30: support member, 38: fluid pressure feeding means, 40 Niskart, 42: weight.

Claims (3)

[Claims] (1) A concrete supply pipe whose one end is connected to a concrete supply means and whose other end is provided with a check valve that allows concrete to be discharged; a membrane that is attached in a liquid-tight manner and is capable of coming into contact with the surface where the concrete is to be placed; a tube that is provided on the outer periphery of the membrane and is capable of expanding and contracting; and a fluid is supplied to the tube to expand the membrane. and a weight surrounding said membrane and attached to said membrane or said tube. (2) A concrete supply pipe whose one end is connected to a concrete supply means and whose other end is equipped with a check valve that allows concrete to be discharged, and which is attached to the concrete supply pipe liquid-tightly and movably in its longitudinal direction. a first sliding member attached to the concrete supply pipe so as to be movable in the longitudinal direction thereof; and a second sliding member disposed around the concrete supply pipe and having an inner peripheral portion thereof a membrane that is fluid-tightly joined to the surface of the concrete and that can come into contact with the surface where the concrete is to be poured; a tube that is provided on the outer periphery of the membrane and that can be expanded and contracted; one end of which is connected to the second sliding member; a plurality of support members connected and having other ends connected to the outer periphery of the membrane or the tube, means for pumping fluid into the tube to expand the membrane, and surrounding the membrane or the tube; Underwater concreting equipment, including a weight attached to the (3) The underwater concrete placing device according to claim (2), further comprising a circumferentially expandable skirt arranged along and attached to the tube.