JPH10121476A - Placing method of underwater concrete and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high quality concrete by restraining separation of a material of concrete to the utmost, preventing occurrence of water contamination and securing safety and economy of construction in the case of directly placing concrete underwater by a concrete pump without using a Ptolemy pipe. SOLUTION: A placing device of underwater concrete places underwater concrete by setting a concrete-conveying pipe 3 underwater and using a concrete pump 2. In this case, the concrete-conveying pipe 3 is made in double-pipe structure by an inner pipe 13 connected to the concrete pump 2 and an outer pipe 14 assembled on a lower end part of the inner pipe 13 free to slide, a bottom cover 15 is provided on a lower end opening of the inner pipe 13, a discharge port of concrete is formed on the side of a lower part, and the discharge port of the inner pipe 13 is closed by the outer pipe 14 free to open and close.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for placing underwater concrete.

[0002]

2. Description of the Related Art Underwater concrete is cast in revetment works in civil engineering works, but in the case of, for example, restoration work in the event of an earthquake, a large amount of rapid construction is required. Conventionally, as such a construction method, for example, a tremy construction method or a construction method using a concrete pump has been adopted.

[0003] The tremy method is generally employed in harbor construction, construction of cast-in-place piles, construction of underground continuous walls, and the like. This is a method in which concrete is poured while preventing the concrete from separating so as not to make contact.

[0004] The concrete pumping method is a method in which a concrete pump is directly piped into water using a concrete pump without using a tremy pipe, and underwater concrete is cast with the pipe.

[0005]

According to the tremy method, the tremee pipe is buried in the water before the concrete is poured.
In addition to the need for facilities such as a work scaffold and a hopper receiver for the installation of the tremy pipe, buoyancy acts on the tremy pipe and construction is not easy when the construction site is deep in water depth. Further, when the water depth is deep, a structure for preventing water leakage from the seam of the pipe into the pipe and a wall thickness that can withstand the water pressure are required.

In addition, when arranging a submerged anchor, a separator, or a submerged reinforcing bar, it is necessary to determine the piping position of the tremie pipe in advance, and a diver or the like is required when installing the tremy pipe, which reduces costs. It costs.

[0007] At the time of concrete casting, a crane is required for installation and cut-off work of the tremy tube, which requires a large amount of work. Such work and management of concrete placement require skill.

When a crane is required for the connection and cut-off work of the tremee pipe, if the crane is installed on a site such as a factory, it is necessary to receive and ship trucks when the factory is operating. Work efficiency is not good due to restrictions on working space and working hours.

[0009] When the construction length of the underwater concrete is long and the horizontal area is large, if the arrangement of the tremy pipes and the order of concrete injection are not appropriate, the quality of the concrete may be deteriorated.

[0010] Since the cast concrete comes up in layers, it is necessary to cast concrete in consideration of the thickness of the latence layer so that an effective member height can be secured, and therefore the construction area is large. And the cost required for the latency treatment increases.

Further, a facility for washing water for cleaning the tremee pipe is required. In the method of casting concrete using the tremee pipe, the lateral pressure of the concrete exerted on the formwork increases sharply at the time of casting and burdens the formwork. It takes.

[0012] On the other hand, the method using a concrete pump does not use the tremy pipe, and thus does not have the above-mentioned disadvantages. However, since the concrete in the concrete transport pipe and the water come into direct contact with each other when placing the underwater concrete, the mortar component is reduced. When concrete is separated by flowing into the water, and when the concrete transport pipe is moved to the next casting place to pile the concrete in layers, the concrete remaining in the concrete transport pipe is submerged. It falls, and also at this time concrete separation occurs. As a result, turbidity occurs in the water, which causes a problem of water pollution.

In addition, since the concrete transport pipe is pushed up by the pressure when the concrete flows out due to the pumping of the concrete at the time of placing the concrete, the discharge port at the tip of the concrete transport pipe is always held in the previously poured concrete. Requires a diver to manually hold down the pipe. Such an operation involves a danger in the water, and costs for it are required.

Since the tip of the concrete transport pipe is a flexible hose, it is easily damaged when it comes into contact with an underwater anchor, a separator, or an underwater rebar.

[0015] When the concrete pump truck is set from the land side and the place where the concrete pump truck is set is on the site of the factory, when the factory is in operation, the work space and the working time due to the loading / unloading work of the truck and the like. Work efficiency is not good due to band restrictions. When a ready-mixed concrete vehicle enters the operating factory premises, it is necessary to take measures to prevent traffic problems with the trucks at the factory and to prevent the dust generated by running the ready-mixed concrete vehicle. Since the factory road is soiled by the mud adhering to the plant, it is necessary to take measures against this.

Further, as an inconvenience common to the method using a tremy pipe and the method using a concrete pump, underwater concrete is purchased from a ready-mixed concrete company different from a concrete casting company, so Due to restrictions on the amount of casting, for example, when it is necessary to rapidly construct a large quantity for the restoration of an earthquake, etc., supply from the same ready-mixed concrete company can not catch up and use concrete from another ready-mixed concrete company As a result, it is difficult to perform high quality construction.

In addition, since it takes time to transport the concrete from the ready-mixed concrete company at the concrete placing site, it is difficult to control the quality of the concrete, especially in summer, and when the arrival of the concrete is delayed due to traffic congestion or the like, the concrete is supplied in a timely manner. Can not do.

An object of the present invention is to eliminate the disadvantages of the prior art and to minimize the material separation of concrete when casting concrete directly into water by a concrete pump without using a tremy tube. Prevents the generation of pollution and prevents the concrete transport pipe from being pushed up by the pressure of concrete flowing out by concrete pumping during concrete placement, ensuring the safety and economy of construction without the need for a diver. Can, and
It is possible to prevent the transport pipe for placing concrete from being damaged by underwater anchors, separators, underwater reinforcing bars, etc., and to supply a constant amount of concrete continuously to obtain high quality concrete. It is an object of the present invention to provide a method and an apparatus for placing underwater concrete that can be performed.

[0019]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to an underwater concrete casting apparatus for setting a concrete transport pipe underwater and using a concrete pump to cast underwater concrete. The concrete transport pipe has a double pipe structure including an inner pipe connected to a concrete pump and an outer pipe slidably combined with a lower end of the inner pipe, and a bottom lid is provided at a lower end opening of the inner pipe and a lower side is provided. Forming a concrete outlet,
In addition, the concrete transportation pipe is formed of a steel pipe, and the bottom lid has a conical shape.

As a construction method, in a method of placing concrete transport pipes in water and placing concrete underwater from the concrete transport pipes using a concrete pump, the concrete transport pipe is connected to the concrete pump. A double pipe structure of a pipe and an outer pipe slidably combined with the lower end of the inner pipe,
A bottom lid is provided at the lower end opening of the inner pipe and a concrete discharge port is formed on the lower side, and when the concrete is poured into water in layers, the outer pipe is slid upward along the inner pipe and With the inner pipe protruding downward, insert the outer pipe into the concrete that has already been cast and pour the concrete with the discharge port of the inner pipe in the concrete,
After the casting, the concrete pipe is moved to the next casting place with the outer pipe being slid downward to close the discharge port of the inner pipe with the outer pipe.

According to the first and fourth aspects of the present invention, there is provided a method for placing underwater concrete by setting a concrete transport pipe in water and placing the underwater concrete from the concrete transport pipe using a concrete pump. The inner pipe connecting the concrete transport pipe to the concrete pump and the outer pipe slidably combined with the lower end of the inner pipe have a double pipe structure. When the concrete discharge port is formed and the concrete is poured into the water in layers, the outer pipe is slid up along the inner pipe and the inner pipe is projected below the outer pipe. By inserting the outer pipe into the concrete and placing the concrete with the outlet of the inner pipe in the concrete, Upper and lower swing of the transport tube can be prevented, backflow into the inner tube of the water after concrete 設直 can be prevented, and the diver can secure construction rather also necessary for that.

Further, the construction can be carried out with a concrete mixer ship equipped with a concrete pump, the workability of the construction is improved, a constant amount of concrete can be supplied continuously, and the lateral pressure of the concrete applied to the formwork at the time of casting is rapidly increased. It is possible to obtain high-quality concrete without increasing the number of concrete transport pipes, and furthermore, it is possible to set the concrete transport pipe freely at the place where the concrete is to be poured.

After the casting, the concrete pipe is moved to the next casting place by sliding the outer pipe downward and closing the discharge port of the inner pipe with the outer pipe, thereby separating the concrete material. Water pollution can be prevented.

According to the second aspect of the present invention, in addition to the above functions, the concrete transport pipe is formed of a steel pipe, so that the concrete transport pipe is not damaged even when it comes into contact with the underwater anchor, the separator, and the underwater rebar.

According to the third aspect of the present invention, in addition to the above-mentioned operation, the bottom lid is formed in a conical shape so that the concrete and water come into rapid contact with each other at the start of concrete casting, so that the mortar component flows out. prevent.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing a state in which a concrete transport pipe is connected to a concrete pump installed in a concrete mixer ship, showing an embodiment of an underwater concrete casting device of the present invention. FIG. 2 is an overall perspective view of the same concrete mixer ship. The concrete transport pipe according to the present invention is connected to a concrete pump mounted on a concrete mixer ship. Referring to the entire structure of the concrete mixer ship, in FIG. 2, 1 is a concrete mixer ship, 2 is a concrete pump, 4 is a concrete pump. A char plant, 5 is a cement tank, 6 is an aggregate storage, and 7 is a telescopic shuttle boom.

As shown in FIGS. 3 and 4, the concrete pump 2 has a plurality of booms 2b sequentially connected to a boom post 2a by means of a hydraulic cylinder so as to be able to swing up and down, and a concrete transport pipe 2c is connected to provide a power unit for discharging concrete. As shown in FIG. 1, a concrete transport pipe 3, which is a main part of the present invention, is connected to the tip of the concrete pump 2 as shown in FIG.

The concrete transport pipe 3 is connected to the tip of the concrete transport pipe 2c on the side of the concrete pump 2, and the fixing means will be described. As shown in FIG. 7, a docking hose at the end of the boom of the concrete pump 2
12 and concrete transport pipe 3 are connected by flange 10 and fixed with bolts.

Then, a hanging jig 11 is attached to the concrete transport pipe 3 in order to prevent the concrete transport pipe 3 from dropping, and the hanging jig 11 is hung from a hanging piece 8 provided at the end of the boom by a hanging wire 9 to concrete. The transport pipe 3 is fixed to the boom of the concrete pump 2.

As the docking hose 12, for example, a 6-inch diameter abrasion-resistant high-pressure hose is used, and the suspension wire 9 is 16 mm in diameter.

The concrete transport pipe 3 is a docking hose.
The inner pipe 13 is connected to the concrete pump 2 through the inner pipe 12 and has an outer pipe 14 slidably combined with the lower end of the inner pipe 13.

The inner tube 13 is designed to withstand the pressure of concrete pumping, the abrasion of concrete aggregates and water pressure.
The material is a carbon steel pipe for general structural use having a diameter of 6 inches. In addition, in order to cope with the water depth of 7 to 9 m where the underwater concrete is poured, the lower inner tube 13a is made to have a length of, for example, 9 m, and the upper inner tube 13b having a length of 6 m is added thereto, and the length is adjustable. And

As shown in FIG. 6, a bottom cover 15 is provided at the opening at the lower end of the lower inner tube 13a, and a concrete discharge port 16 is formed on the lower side of the inner tube 13a. The discharge port 16 is for reducing the material separation of the concrete and for resisting the water depth below the deep water, and has a length of about 15 cm and a width of about 10 cm.

The bottom cover 15 was made of a lump of pig iron to prevent abrasion due to the discharged concrete, and was formed into a conical shape with a diameter of 8 inches by lathing.

On the outer peripheral portion of the inner tube 13a, a numerical value indicating the water depth from the tip of the discharge port 16 by, for example, 50 cm is written with paint such as paint so that the water depth can be easily determined.

The outer tube 14 opens and closes the discharge port 16 of the inner tube 13a, and is formed, for example, to have a diameter of 7 inches and a length of 2.5 m.
As shown in FIG. 6, a reinforcing bar 17 is attached by welding along the opening at the lower end in order to prevent the concrete from leaking in close contact with the bottom cover 15 of the inner tube 13a at the time of lowering.

The sliding and fixing mechanism of the outer tube 14 is shown in FIG.
As shown in the figure, the concrete transport pipe 2c of the concrete pump 2 is supplied from the compressor of the concrete mixer ship 1.
An air hose 18 is disposed along the air hose, and the air hose 18 is connected to an air cylinder 20 via an air switching valve 19, and the air switching valve 19 and the air cylinder 20 are connected to the inner pipe 13a of the concrete transport pipe 13 with flat steel. Fix it.

An outer tube fixing jig 21 made of a steel pipe having a diameter of 25 mm is connected to the lower end of the piston 20a of the air cylinder 20, and the outer tube fixing jig 21 is fixed to the upper side of the outer tube 14. As a result, the outer tube 14 is supported by the outer tube fixing jig 21 and the piston 20
It slides up and down by the vertical movement of a.

Next, a method of casting underwater concrete by the concrete pump 2 using the concrete transport pipe 3 will be described with reference to FIGS. For example, when reinforcing the existing revetment 22, a front formwork 23 is assembled in the sea along the front of the revetment 22. In the figure, 24 is a guide material for mountain retaining, 25 is a guide material supporter, 26 is a supporter supporter, 27 is a wife formwork, and a lower separator 28a, an upper separator 28b, and a concrete casting site are shown. An underwater anchor 29 and underwater rebar 30 are provided.

The concrete mixer ship 1 is moved to the place where the underwater concrete is poured, and is moored at a predetermined place with the anchor and the mooring rope, and the concrete transport pipe 3 is set at the concrete placing position. In this case, the concrete transport pipe 3 is set at a position as close as possible to the existing revetment 22 as shown in FIG. 8 so as not to apply the lateral pressure of the concrete to the formwork 23 when the concrete is poured.

9 and FIG. 10, the layers are stacked in layers from left to right in order from the center according to the order of the places to be driven. At this time, as shown in FIG. 5, four concrete inlets are provided, for example, at a horizontal distance of 4 m for each casting caisson, and while the concrete filling condition is checked in red, the next concrete inlet is used. Pour till the thickness becomes 50cm.

The concrete is poured by using the concrete pump 2 to discharge the concrete from the discharge port 16 at the tip of the concrete transport pipe 3. Then, when it is confirmed that the thickness of the next concrete to be cast is 50 cm in red, the pumping of the concrete is stopped, and the air switching valve 19 is operated to operate the air pressure of the air pumped through the air hose 18. The outer cylinder 14 is slid by moving the outer tube fixing jig 21 downward by operating the air cylinder 20, and the outer tube 14 closes the discharge port 16 of the inner tube 13a.

As described above, the discharge port 16 of the inner pipe 13a is closed with the outer pipe 14, and the concrete transport pipe 3 is pulled out and moved to the next input port so that the concrete inside does not leak. In this state, since the reinforcing bar 17 provided at the lower portion of the outer tube 14 is in close contact with the lower end of the inner tube 13a, concrete leakage can be completely prevented. Since the concrete transport pipe 3 is formed of a steel pipe, the concrete transport pipe 3 is not damaged even if the concrete transport pipe 3 comes into contact with the underwater reinforcing bar 30 during movement.

When the concrete transport pipe 3 has been moved to the next inlet, the air cylinder 20 is operated to activate the outer pipe fixing jig.
21 is moved upward, the outer tube 14 is slid, and the discharge port 16 is
Is released, the bottom cover 15 at the tip of the inner tube 13a and the outer tube 14 are inserted into the already poured underwater concrete, and the concrete pump 2 starts pumping. At this time, outer tube 14
Serves as a guide for the inner tube 13a.

Thus, since the tip of the concrete transport pipe 3 is a double pipe of the outer pipe 14 and the inner pipe 13a, it is possible to prevent the concrete transport pipe 3 from swaying up and down during concrete pumping. By providing a bottom lid 15 at the end of the inner pipe 13a and discharging concrete from the slit-shaped discharge port 16 on the side, separation of concrete in water can be prevented, and concrete can be removed immediately after placing concrete. It also prevents the water from flowing back too rapidly into the pipe. In this case, since the bottom cover 15 is formed in a conical shape, rapid contact of concrete with water can be prevented, and separation of concrete by outflow of mortar can be effectively prevented.

It should be noted that the concrete is fed at a rate of 60 to 70 hours per hour in consideration of the lateral pressure of the concrete exerted on the formwork and the capacity of the pump.
The operation is controlled to be within the range of m ³ .

Thereafter, the same operation is sequentially repeated to place the first layer of concrete, and when this is completed, the second layer of concrete is placed. As shown in FIGS. 9 and 10, this second layer of concrete was placed at the center of the caisson where the first layer of concrete was recessed, and the thickness of the red cast was confirmed. It is poured so as to fill the concave portion.

Since the material separation of the underwater concrete can be visually confirmed by the turbidity of the water at the casting location, the concrete placing height indicated on the outer peripheral portion of the concrete transport pipe 3 and the rising height by the red are carefully checked. In order to always embed the discharge port 16 at the tip of the concrete transport pipe 3 in the already poured concrete by 30 to 40 cm, the outer pipe 14 is effectively used for the slide stroke and is managed. Such placement management can be operated mechanically from a ship with a remote controller at hand, and does not require skill.

At this time, the behavior of the front formwork 23 and the separator due to the side pressure of the concrete is checked, and if an abnormality is found, the casting of the concrete is interrupted, and after a few hours, it is confirmed that there is no abnormality in the behavior. Resume concrete casting.

In this way, the concrete in the underwater part is poured in layers, and when it reaches the aerial part, the top part of the concrete is pushed up from one side by a single push. At this time, the concrete latence in the underwater part is raised so as to be pushed to the side of the formwork 27 in the concrete casting direction, and the raised latence is discharged to the land side by a sand pump. Then, after the concrete surface is subjected to the latence treatment, the top of the concrete is finished flat with a wooden trowel.

When the sand pump cannot reliably treat the latency, a retarder is sprayed on the concrete surface and treated with high-pressure jet water at a low tide at low tide. At this time, a pollution control curtain is extended around the work place to prevent marine pollution.

In addition, when placing the underwater concrete, the concrete in the underwater part is launched at high tide as much as possible so that the lateral pressure of the concrete can be reduced in consideration of the influence of the lateral pressure of the concrete on the formwork and the tide level when the concrete is launched. The concrete placement control is performed so that the concrete surface is not scoured by the waves when the tide rises above the high tide surface (HWL) at low tide.

[0053]

As described above, the method and the apparatus for placing underwater concrete according to the present invention require the use of a concrete transport pipe when placing concrete directly into water by a concrete pump without using a tremy pipe. Because it has a double pipe structure and a bottom plate and a slit-shaped discharge port at the bottom,
Material separation of concrete can be suppressed as much as possible, and generation of water pollution can be prevented.

Further, it is possible to prevent the concrete transport pipe from being pushed up by the pressure when the concrete flows out due to the pressure of the concrete at the time of placing the concrete. Therefore, a diver is not required and the safety and economy of the construction can be secured.

Further, since the concrete transport pipe is made of steel pipe, it is possible to prevent the concrete transport pipe from being damaged by an underwater anchor, a separator, an underwater reinforcing bar, etc., while moving the concrete pipe. The pipe can be freely set at the concrete pouring position, the underwater concrete can be filled uniformly, and the concrete can be supplied continuously at a constant rate to obtain high-quality concrete. is there.

[Brief description of the drawings]

FIG. 1 is a perspective view of an embodiment of an underwater concrete casting device according to the present invention, in which a concrete transport pipe is connected to a concrete pump installed on a concrete mixer ship.

FIG. 2 is an overall perspective view of a concrete mixer ship showing an embodiment of an underwater concrete placing device of the present invention.

FIG. 3 is a plan view of a concrete pump showing an embodiment of an underwater concrete placing device of the present invention.

FIG. 4 is a front view of a concrete pump showing an embodiment of a submerged concrete placing device of the present invention.

FIG. 5 is a front view of the upper part of the concrete transport pipe showing the embodiment of the underwater concrete placing device of the present invention.

FIG. 6 is a front view of the lower part of the concrete transport pipe showing the embodiment of the underwater concrete placing device of the present invention.

FIG. 7 is a side view of an embodiment of a method for placing underwater concrete according to the present invention, in which a concrete transport pipe is installed.

FIG. 8 is a plan view showing the embodiment of the underwater concrete casting method according to the present invention with a form set.

FIG. 9 is a longitudinal sectional front view showing a placing order of the embodiment of the method of placing underwater concrete according to the present invention.

FIG. 10 is an explanatory diagram showing a placing order of the embodiment of the method of placing underwater concrete according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Concrete mixer boat 2 ... Concrete pump 2a ... Boom post 2b ... Boom 2c ... Concrete transport pipe 3 ... Concrete transport pipe 4 ... Batcher plant 5 ... Cement tank 6 ... Aggregate storage 7 ... Telescopic shuttle boom 8 ... Hanging piece 9 ... hanging wire 10 ... flange 11 ... hanging jig 12 ... docking hose 13, 13a, 13b ... inner tube 14 ... outer tube 15 ... bottom lid 16 ... discharge port 17 ... rebar 18 ... air hose 19 ... air switching valve 20 ... air cylinder 20a ... Piston 21 ... Outer tube fixing jig 22 ... Revetment 23 ... Front formwork 24 ... Conducting material 25 ... Conducting material support work 26 ... Conducting material support work receiving belly 27 ... Wife formwork 28a ... Lower separator 28b ... Upper separator 29 ... underwater anchor 30 ... underwater rebar

Claims (4)

[Claims] 1. A concrete transportation pipe is set in water,
In a submersible concrete pouring device for pouring underwater concrete using a concrete pump, there is provided an inner pipe connecting the concrete transport pipe to a concrete pump and an outer pipe slidably combined with a lower end of the inner pipe. An underwater concrete casting apparatus characterized by having a double-pipe structure, a bottom cover provided at a lower end opening of an inner pipe, and a concrete discharge port formed at a lower side. 2. The underwater concrete casting device according to claim 1, wherein the concrete transport pipe is formed of a steel pipe. 3. The underwater concrete pouring device according to claim 1, wherein the bottom lid has a conical shape. 4. A concrete transportation pipe is set in water,
In a method of casting underwater concrete from a concrete transport pipe using a concrete pump, an inner pipe connecting the concrete transport pipe to the concrete pump and an outer pipe slidably combined with a lower end of the inner pipe are provided. The inner pipe is provided with a bottom lid at the lower end opening and a concrete discharge port is formed on the lower side, so that when the concrete is poured into water in layers, the outer pipe is aligned with the inner pipe. With the inner pipe protruding below the outer pipe, insert the outer pipe into the already-cast concrete and place the concrete with the discharge outlet of the inner pipe in the concrete. Then, after casting, the concrete pipe is moved to the next casting place with the outer pipe slid downward and the discharge pipe of the inner pipe closed with the outer pipe. Hitting 設方 method of Nkurito.