JPS63304876A - Submerged slurry casting method and apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial Application Field" The present invention relates to an underwater casting method and underwater casting apparatus for slurry-like materials such as concrete, mortar, and coal ash slurry.

``Prior art'' In general, tremie pipes are used to cast slurry materials such as concrete underwater, and the tremie pipes are joined together and the discharge port at the tip is placed at the bottom of the water. The slurry-like material is delivered to the tremie tube by placing the slurry at a certain position and dropping the slurry into it or by pumping it.

Conventionally, a simple circular pipe l having a diameter of about 200 to 250III11, as shown in FIGS. 5 and 6, has been used for such underwater casting. As shown in FIG. 7, this vibrator l is held in a state in which the discharge port +a at the tip is slightly raised from the pouring bottom surface G at the bottom of the water and pushed into the uncured slurry S that has already been poured. The concrete is poured toward the bottom surface G of the concrete. The discharge port (tip of the tremor tube) la of this tremor tube (pipe) L is pushed into the previously cast uncured slurry S to avoid contact with water so as not to reduce the density and strength of the slurry. The purpose is to avoid
The new slurry is cast while spreading the previously cast uncured slurry S around it.

"Problems to be Solved by the Invention" However, in the underwater casting of slurry using such a tremor tube, there are the following problems to be solved.

■ If the dropping height of the slurry is high, or if the pumping pressure or pouring speed is high, the slurry discharge speed of the tremie pipe will also increase, and the discharged slurry will be directed to the bottom of the pouring or below the discharge port. A situation occurs in which the uncured slurry S hits the uncured slurry S that has already been cast, and this also disturbs the uncured slurry S that has already been cast, resulting in water contamination and a decrease in density and strength due to the entrainment of water due to the disturbance. occur.

■ When the slurry is soft or light with relatively high fluidity, or when the penetration of the pouring tube light into the uncured slurry S is shallow, etc. As shown in FIG. 7, the slurry discharged from the discharge port 1a of the tremor tube 1 flows upward along the periphery of the tremor tube 1 instead of spreading the uncured slurry around, as shown by the chain line R in FIG. A situation arises in which the slurry S is placed on top of the already poured slurry S, and the contact surface with water becomes larger, resulting in a decrease in strength and density, and the water becomes more contaminated.

■ As shown in Figure 7, the slurry pouring shape is mountain-shaped, with the area around the tremor tube i rising high and the height decreasing as it gets farther away, with the apex around the pouring tube. If you want to pour slurry evenly over a wide area, you can either place a large number of tremor tubes and narrow the spacing between them to reduce the difference in height between the peaks and valleys, or mix the slurry in a way that gives it self-leveling properties. It is necessary to add agents, which results in high costs.

The present invention has been proposed in view of the above circumstances, and its purpose is to provide an underwater pouring method and an underwater pouring device for slurry that can effectively solve the problems of the prior art described above. It is something to do.

``Means for Solving the Problems'' Therefore, in the method for placing slurry underwater according to the present invention, slurry is fed into a slurry placing pipe having a discharge port near the bottom of the water, and is discharged from the discharge port toward the bottom of the water. In the underwater pouring method of pouring on the water bottom, a guide plate is provided around the discharge port of the slurry pouring pipe, and when the slurry is discharged, the guide plate guides the slurry from the water bottom. This method is characterized by pouring slurry onto the water bottom along a guide plate while suppressing splashing.

Further, the underwater slurry pouring device is provided with a guide plate surrounding a slurry discharge port on the outer periphery of the distal end of a slurry pouring pipe for pouring slurry into water, and the outer diameter of the guide plate is The size is set to be at least twice the outer diameter of the slurry pouring pipe.

``Operation'' The guide plate at the tip of the pouring pipe is placed parallel to the pouring bottom surface on the bottom of the water, and the slurry is discharged from the discharge port.When the slurry is discharged from the discharge port, the rebound of the pouring slurry discharged from the discharge port is suppressed by the guide plate. The turbulence and upward flow (splash) caused by the splashing of the pouring slurry are converted into a horizontal slurry flow.

"Embodiments" Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Figure 1 shows the state in which slurry is poured into water.
Reference numeral A in the figure indicates an underwater casting device used in this underwater casting method. This underwater casting device A includes a slurry casting pipe 10 connected to a tremi pipe T for transporting slurry, and a slurry casting pipe 10 that is provided on the outer periphery of the tip of the slurry casting pipe 10 and extends radially outward of the casting pipe IO. Annular guide plate 1
1 and the slurry pouring pipe! A cylindrical cover 12 is integrally fixed to the periphery of the guide plate 11 so as to surround the outer periphery of the guide plate 11.
It is mainly composed of.

The guide plate 11 suppresses the splashing of the slurry discharged from the discharge port 10a of the slurry casting pipe 10,
This prevents the slurry from being disturbed or flowing upward (splashing up) due to splashing, and its own outer diameter D1 is designed to prevent the slurry from splashing from the pouring bottom surface G. The outer diameter of the installed pipe 10 is set to be approximately twice or more. This guide l1E11
If the outer diameter D+ is less than twice the outer diameter of the slurry casting pipe IO, the splashing of the casting slurry cannot be suppressed, which is disadvantageous.

Further, the cover 12 surrounding the outer periphery of the slurry pouring pipe 1O is formed to have a dimension longer than at least the thickness of the slurry to be poured, so that when pulling up this underwater pouring device A after pouring the slurry, the cover 12 is placed on the guide plate 11. This is to prevent slurry from getting on the surface.

Examples of this underwater casting method will be described below.

When pouring a slurry-like substance such as concrete, mortar, or coal slurry on the pouring bottom surface G of the underwater bottom, the slurry pouring pipe 10 of the underwater pouring device A is arranged almost perpendicular to the pouring bottom surface G. At the same time, the discharge port 10a at the tip is held in a state slightly lifted from the bottom surface G of pouring.

In this state, the slurry is fed into the slurry casting pipe 10 through the tremor pipe T by a slurry supply means (not shown), and the slurry is discharged from the discharge port 10a at the tip of the casting pipe, and the slurry is constantly discharged from the discharge port. While maintaining the state buried in the slurry and suppressing the splashing of the slurry from the pouring bottom surface G by the guide plate 11,
The slurry is placed on the bottom of the water along the guide plate ti.

In addition, examples of the slurry supply means include a slurry pressure pump such as a grout pump.
It is not limited to pressure pumps in particular, but it is
A hopper or the like may be provided at the upper end of the container to allow the slurry to fall therein.

When the slurry is cast underwater in this way, the slurry discharged from the discharge port 10a of the slurry casting pipe 10 is
As shown by arrow A, it collides vertically with the pouring bottom surface G and rebounds, and then tries to flow upward, but the guide plate 11
The upward flow is suppressed by the guide plate 11.
Since the slurry is pushed out horizontally along the cast slurry, there is less disturbance (splashing up) of the cast slurry caused by the cast slurry, and therefore less water is drawn in, which prevents water from becoming cloudy and from reducing the strength of the slurry. , high-quality pouring is performed.

In addition, by eliminating the direct upward flow, the slurry being poured does not rise along the slurry pouring pipe lO and cover the already poured slurry one after another. The contact of the slurry with water is reduced, and high-quality slurry can be poured without causing a decrease in the density or strength of the slurry.

Furthermore, since the new pouring slurry spreads out the uncured slurry that has already been poured in the horizontal direction, it is possible to form a gentle pouring slope without the area around the slurry pouring pipe 10 being extremely swollen. , it becomes easy to pour flatly over a wide area.

FIGS. 2 to 4 show an embodiment of an underwater casting apparatus suitable for use in carrying out such an underwater casting method. This underwater casting device has an air-driven valve 20 disposed near the tip of the slurry casting pipe 10, an annular guide plate 11 at the tip of the valve 20, and a slurry casting pipe 10. Pipe 10 installed around the outer circumference of lO
It has a double cylinder structure in which a cover 12 covering the valve 20 is provided.

The valve 20 includes a flanged casing 24;
It is composed of a rubber valve membrane 25 that forms the flow path of the cast pipe, and an air hose 26 is installed on the side of the casing 24.
is connected. This air hose 26 is piped along the concrete casting pipe 10 to above the water, and the other end is connected to a compressor via a switching valve or a pressure reducing valve. A support flange 27 is provided between the slurry pouring pipe IO and the cover 12, and a drain plug 28 is provided at the lower end of the cover 12.

Then, from the air hose 26 to the casing 2 of the valve 20
Slurry is supplied into the slurry pouring pipe 10 with the valve 20 closed by sending compressed air between the valve membrane 25 and the valve membrane 25. Next, the air in the valve 20 is removed using the air hose 26, and the slurry is placed in water with the valve 20 in an open state. After pouring slurry into water, supply compressed air into the valve while leaving a predetermined amount of slurry in the slurry pouring pipe (an amount that can prevent water from entering or backflowing into the slurry pouring pipe). , close the valve again.

When the underwater casting apparatus A is configured as described above, the opening degree of the valve membrane 25 can be freely adjusted by controlling the pressure of the air inside the casing 24 of the valve 20. As a result, the remaining amount of slurry and the opening/closing of the valve 20 can be easily adjusted, a predetermined remaining amount of slurry can be secured in the slurry pouring pipe IO, and backflow of water into the pipe can be prevented. Therefore, it is possible to achieve high-quality slurry casting underwater. Further, by opening and closing the valve 20, there is an advantage that contamination of water due to relocation of the pouring device A and contact of the initial slurry with water at the start of pouring can be prevented as much as possible.

"Effects of the Invention" As explained above, according to the underwater pouring method of the present invention, the guide plate provided around the discharge port of the slurry pouring pipe suppresses the splashing of the pouring slurry, preventing disturbance caused by the splashing and causing the slurry to flow upward. Since the flow (spouting up) is converted into a horizontal flow of slurry and discharged, less water is involved, and water turbidity and reduction in slurry strength can be reduced.

In addition, the slurry being poured does not rise along the pouring pipe and cover the already poured slurry one after another.
Therefore, contact of the new slurry with water is reduced, and slurry can be poured with good quality without causing a decrease in density or strength of the slurry.

Furthermore, since the new pouring slurry spreads out the uncured slurry that has already been poured in the horizontal direction, it is possible to form a gentle pouring slope without excessive swelling around the pouring pipe, making it possible to widen the area. It becomes easy to pour the concrete evenly over the area.

Further, the underwater pouring device of the present invention is provided with a guide plate surrounding the slurry discharge port on the outer periphery of the distal end of the slurry pouring pipe, and the outer diameter of the guide plate is set to be equal to the outer diameter of the slurry pouring pipe. Since the size is set to be at least twice as large, it is possible to reliably prevent the slurry from rebounding from the bottom surface of the pouring surface, and to push out the pouring slurry in the horizontal direction. Apparatus suitable for use can be provided.

[Brief explanation of the drawing]

The drawings are shown to explain the present invention in detail, and Fig. 1 is a schematic diagram showing the state in which slurry is poured onto the bottom surface of the submerged casting system, and Figs. 2 to 4 are illustrations of the underwater casting equipment. Fig. 2 is a half sectional view, Fig. 3 is a bottom view, Fig. 4 is a sectional view taken along the line ■-■ in Fig. 2, and Fig. 5 is a sectional view of the tremor tube. , FIG. 6 is a plan view, and FIG. 7 is a schematic diagram for explaining the conventional construction method. A: Underwater pouring equipment, T: Tremi pipe, G: Bottom surface of pouring, S: Already uncured slurry, lO: ...Slurry pouring pipe, 11...
... Guide plate, 12 ... Cylindrical cover, 20.
... Valve, 24 ... Casing, 25
... Valve membrane, 26 ... Air hose.

Claims (1)

[Scope of Claims] 1) In an underwater casting method, the slurry is poured into a slurry casting pipe having a discharge port near the water bottom, and is discharged from the discharge port toward the water bottom to cast the slurry on the water bottom. A guide plate is provided around the discharge port of the pouring pipe, and when the slurry is discharged, the slurry is driven onto the water bottom along the guide plate while suppressing the splash of the slurry from the water bottom. A method for placing slurry underwater, characterized by: 2) A guide plate surrounding the slurry discharge port is provided on the outer periphery of the tip of a slurry casting pipe for casting slurry into water, and the outer diameter of the guide plate is equal to the outer diameter of the slurry casting pipe. An underwater slurry casting device, characterized in that the slurry is set to be at least twice as large as the above.