JP2021123949A - Drain device, and liquid drain method - Google Patents

Abstract

To provide a drain device capable of easily draining liquid in a standing steel pipe having a bottom cover with a simple device, and to provide a liquid drain method using the drain device.SOLUTION: A drain device comprises: a submerged pump installed in a standing steel pipe having a bottom cover and sucking remaining liquid; and a lifting pipe whose lower end portion is provided with a pump connection portion connected with a discharge port of the submerged pump and whose upper end portion is provided with an upper side drain port draining liquid flowing from the pump connection portion. The lifting pipe is provided with a check valve preventing liquid flowing from the pump connection portion from flowing back.SELECTED DRAWING: Figure 3

Description

The present invention relates to a drainage device for discharging a liquid staying in a steel pipe in an upright posture having a bottom lid, and a method for discharging the liquid staying in the steel pipe using the drainage device.

Conventionally, as the underground space has become larger in scale, the reverse construction method is often adopted for the construction of structures in order to shorten the construction period and consider the surrounding environment. The reverse striking method is a method of constructing an underground skeleton from the upper floor to the lower floor by sequentially repeating excavation of the ground and construction of the skeleton while using the floor beam of the building body as a girder support. Before starting excavation of the ground, a structural pillar used to support the floor beams will be installed in the ground.

As the structural columns, steel columns, columns with a concrete-filled steel pipe structure, and the like are adopted. For example, Patent Document 1 discloses a structural pillar with a concrete-filled steel pipe structure and a method for constructing the same. Specifically, a steel pipe with a bottom lid is built in a pile hole constructed by excavating while filling a stabilizer, etc. while injecting fresh water into the hollow part, and concrete is cast in the pile hole to cast a place. Build a pile and join the lower end of the steel pipe to the cast-in-place concrete pile.

After that, concrete is placed in the hollow part of the steel pipe instead of fresh water by any means to construct a concrete-filled steel pipe structure pillar in the ground. As described above, when the steel pipe is built in the pile hole, if ballast water such as fresh water is injected into the hollow portion, the influence of the buoyancy on the steel pipe can be offset from the stabilizing liquid, and the steel pipe can be built with high accuracy.

JP-A-2002-54164

However, since the steel pipe used for the structural pillar has a narrow opening, a small submersible pump must be inserted when discharging the fresh water staying in the hollow portion. It is assumed that such a small submersible pump does not have sufficient discharge capacity to pump the sucked fresh water to the upper end of the steel pipe and drain it. In such a case, a plurality of pumps and a pump pipe are used. The equipment used for drainage tends to be complicated, such as arranging the pipes in series for drainage, and the work is complicated.

On the other hand, as described in Patent Document 1, a method of discharging the fresh water while placing concrete in the fresh water in the steel pipe column is also conceivable, but the management method of the concrete to be placed is stipulated. However, there is a problem in quality control.

The present invention has been made in view of such a problem, and a main object thereof is a drainage device capable of easily draining a liquid in a steel pipe in an upright posture having a bottom lid with a simple device. And to provide a method of draining a liquid using a drainage device.

In order to achieve such an object, the drainage device of the present invention is installed in an upright steel pipe having a bottom lid, and has a submersible pump that sucks in the retained liquid and a pump connection portion connected to the discharge port of the submersible pump at the lower end. The pump connecting portion is provided with a pumping pipe provided at an upper end portion thereof and provided with an upper discharge port for discharging the liquid flowing from the pump connecting portion, and the pumping pipe is provided in the vicinity of the pump connecting portion. It is characterized in that a check valve for preventing the backflow of the liquid flowing in from is provided.

According to the drainage device described above, since the pumping pipe is provided with a check valve, the liquid that is sucked up by the submersible pump, passes through the check valve from the pump connection, and flows into the pumping pipe is operated by the submersible pump. Even if the pump is stopped, it is stored in the pumping pipe without flowing back to the submersible pump side.

Therefore, when pumping the liquid that stays in the steel pipe with the bottom lid, even if the height difference between the water level of the liquid and the opening position of the upper end of the steel pipe is large and the discharge capacity of the submersible pump cannot discharge the liquid that stays in the water. By storing the liquid sucked up by the pump in the pumping pipe and lifting it out from the steel pipe together with the pumping pipe, the liquid can be easily and quickly drained from the steel pipe.

Further, the drainage device of the present invention is characterized in that a side discharge port for discharging the liquid is provided on the side surface of the pumping pipe in the vicinity of the check valve so as to be openable and closable.

According to the drainage device described above, when the liquid sucked up by the submersible pump and stored in the pumping pipe is discharged, it can be easily drained from the side discharge port without performing complicated work such as tilting the pumping pipe. It will be possible.

Further, the liquid discharge method of the present invention is a liquid discharge method for discharging the liquid staying in the steel pipe in an upright posture having a bottom lid by using the drainage device of the present invention, and is installed in the steel pipe. The step of operating the submersible pump of the drainage device to discharge the liquid from the upper discharge port of the pumping pipe and the liquid level of the liquid are lowered so that the liquid is no longer discharged from the upper discharge port of the pumping pipe. At that time, the operation of the submersible pump was stopped, the drainage device was taken out from the steel pipe, the liquid stored in the pumping pipe was discharged by the check valve, and the liquid in the pumping pipe was discharged. The drainage device is installed in the steel pipe in which the water level of the liquid has dropped, the liquid is allowed to flow into the pumping pipe via the submersible pump, and then the drainage device is taken out from the steel pipe and the check valve is used. It is characterized by having a step of discharging the liquid stored in the pumping pipe.

According to the above-mentioned liquid discharge method, the liquid staying in the steel pipe having the bottom lid can be discharged by operating the submersible pump to a water level that can be pumped by the discharge capacity of the submersible pump, and then pumped by the submersible pump. The liquid below the water level can be discharged by sucking it with a submersible pump, storing it in the pumping pipe, lifting it up from the steel pipe together with the pumping pipe, and taking it out. Therefore, even a liquid that stays in a steel pipe with a narrow opening and a long member length, such as that used for a structural pillar, can be quickly and easily used without being affected by the performance of the submersible pump by using a drainage device. It is possible to drain the liquid in the steel pipe.

According to the present invention, by providing the check valve in the pumping pipe, the liquid sucked by the submersible pump can be stored in the pumping pipe. By lifting and removing the entire pipe from the steel pipe, the liquid in the steel pipe can be quickly and easily discharged.

It is a figure which shows the construction procedure of the structural pillar in the reverse driving method in embodiment of this invention (the 1). It is a figure which shows the construction procedure of the structural pillar in the reverse driving method in embodiment of this invention (the 2). It is a figure which shows the drainage apparatus which concerns on this invention. It is a figure which shows the procedure of the liquid discharge method using the drainage device of this invention (the 1). It is a figure which shows the procedure of the liquid discharge method using the drainage device of this invention (the 2).

The drainage device and the liquid drainage method of the present invention can be adopted regardless of the purpose of the steel pipe having the bottom lid built in the standing posture. In the present embodiment, it is used when constructing a concrete-filled steel pipe structure (hereinafter referred to as CFT structure) in the reverse casting method, which is one of the methods for constructing an underground frame or an underground structure of a building. Taking a steel pipe as an example, the details will be described with reference to FIGS. 1 to 5.

As shown in FIG. 2C, the CFT structure Shinbashira 1 is formed by placing filled concrete C in a steel pipe 2 with a bottom lid having a bottom lid 2a at the lower end of a circular or square steel pipe. On the lower surface of the bottom lid 2a, for example, a steel material 2b such as a cross H steel material in which H-shaped steels are combined in a cross shape and the horizontal cross section has a cross shape is hung.

In order to construct such a CFT structure Shinbashira 1, first, as shown in FIG. 1A, the underground hole H is drilled while supplying the stabilizer W to the planned construction position of the foundation pile. do. After that, the reinforcing bar cage 5 is built in the underground hole H at a predetermined depth.

Next, as shown in FIGS. 1 (b) and 1 (c), the steel pipe 2 with a bottom lid is hung from the underground hole H to a predetermined depth and built, but the inside of the underground hole H is the underground hole H. It is in a state of being filled with the stabilizer W supplied at the time of drilling. For this reason, when the steel pipe 2 with a bottom lid is suspended in the underground hole H, buoyancy acts to make the steel pipe 2 with a bottom lid unstable, and the steel pipe 2 with a bottom lid tends to stay high, and the construction work tends to be complicated.

Therefore, while injecting ballast water B into the steel pipe 2 with a bottom lid and gradually increasing the weight, the steel pipe 2 with a bottom lid is suspended in the underground hole H to offset the influence of buoyancy. As the ballast water B, any liquid such as tap water or fresh water that can be sucked up by the submersible pump 31 of the drainage device 3 described later may be adopted.

After the steel pipe 2 with a bottom lid is built at a predetermined depth position in this way, a tremie pipe (not shown) is arranged between the structural pillar 1 and the underground hole H, and the reinforcing bar cage 5 and the bottom are placed. As shown in FIG. 1D, concrete is poured to a predetermined height position in the underground hole H so as to bury the bottom portion 2a and the steel material 2b of the steel pipe 2 with a lid to construct a cast-in-place pile P. do.

After that, as shown in FIGS. 2A and 2B, the gap between the underground hole H and the structural pillar 1 is backfilled with the backfill material 6, and the ballast water B staying in the steel pipe 2 with the bottom lid is used. To discharge. Then, as shown in FIG. 2C, the filled concrete C is placed in the steel pipe 2 with a bottom lid to construct the CFT structure Shinbashira 1. In the method of constructing the structural pillar 1 of the CFT structure as described above, in the present embodiment, as shown in FIG. 3, the drainage device 3 is used as a means for discharging the ballast water B staying in the steel pipe 2 with a bottom lid. Be done.

<Drainage device>
As shown in FIG. 3, the drainage device 3 for discharging the ballast water B in the bottom-covered steel pipe 2 includes a submersible pump 31 that can be inserted into the bottom-covered steel pipe 2 and a ballast water B that is sucked up by the submersible pump 31. Has a pumping pipe 32 into which the water flows.

If the submersible pump 31 can automatically control operation and stop while being arranged in the bottom-covered steel pipe 2 and has a shape that can be inserted into the bottom-covered steel pipe 2, the submersible pump 31 has a suction capacity and a discharge. There is no limitation on ability.

The pumping pipe 32 has a pump connecting portion 32a connected to the discharge port of the submersible pump 31 at the lower end, and a check valve 32b for preventing the backflow of ballast water B flowing from the submersible pump 31 is provided near the pump connecting portion 32a. It is provided. Further, the pumping pipe 32 is provided with an upper discharge port 32c at the upper end and a side discharge port 32d on the side surface near the upper side of the check valve 32b, and both the upper discharge port 32c and the side discharge port 32d are provided. , It is possible to discharge the ballast water B that has flowed in through the submersible pump 31.

An opening / closing member 32e is installed in the side discharge port 32d, and the ballast water B can be discharged by opening the opening / closing member 32e. Here, any of the opening / closing members 32e may be adopted, and in the present embodiment, an electromagnetic valve is provided. Further, the side discharge ports 32d are not necessarily provided, and if they are provided, a plurality of side discharge ports 32d may be provided in the circumferential direction and the height direction of the pumping pipe 32.

The drainage device 3 having the above-described configuration is arranged in the vicinity of the bottom lid 2a in the steel pipe 2 with a bottom lid in a state where the side discharge port 32d is closed by the opening / closing member 32e, and the submersible pump 31 is operated. Then, the ballast water B in the bottom-covered steel pipe 2 is sucked up by the submersible pump 31 and discharged toward the pumping pipe 32. The ballast water B discharged to the pumping pipe 32 flows in from the pump connection portion 32a, passes through the check valve 32b, rises, and then is discharged from the upper discharge port 32c.

On the other hand, when the operation of the submersible pump 31 is stopped, the pumping pipe 32 is provided with a check valve 32b in the vicinity of the pump connecting portion 32a, so that the ballast water B flowing into the pumping pipe 32 is discharged from the pump connecting portion 32a. It is stored in the pumping pipe 32 without leaking to the submersible pump 31 side.

Therefore, when the ballast water B in the bottom-covered steel pipe 2 is pumped, the height difference between the water level of the ballast water B and the upper end opening position of the bottom-covered steel pipe 2 is large, and the ballast water B is used in the discharge capacity of the submersible pump. Even when the ballast water B stored in the pumping pipe 32 cannot be discharged to the outside from the upper discharge port 32c of the pumping pipe 32 provided near the upper end opening position of the steel pipe 2 with a lid, the ballast water B stored in the pumping pipe 32 is discharged together with the pumping pipe 32 into the steel pipe 2 with a bottom lid. By lifting and taking out from, it becomes possible to discharge.

Further, since the pumping pipe 32 is provided with the side discharge port 32d, when the ballast water B stored in the pumping pipe 32 is discharged, complicated work such as tilting the pumping pipe 32 is not performed. , Can be easily drained from the side discharge port 32d.

<How to discharge liquid in steel pipe>
The procedure for discharging the ballast water B in the steel pipe 2 with a bottom lid constituting the structural pillar 1 of the CFT structure using the drainage device 3 will be described with reference to FIG. Note that FIG. 4 cites a case where the ballast water B in the bottom-covered steel pipe 2 is discharged after the gap between the underground hole H and the structural pillar 1 is backfilled with the backfill material 6. ..

First, as shown in FIG. 4A, the drainage device 3 is suspended from the upper end opening of the steel pipe 2 with a bottom lid, and the submersible pump 31 is arranged in the vicinity of the bottom lid 2a. After that, the operation of the submersible pump 31 is started to suck up the ballast water B and discharge it from the upper discharge port 32c of the pumping pipe 32. At this time, the opening / closing member 32e of the side discharge port 32d provided in the pumping pipe 32 is in the closed state.

As the drainage work progresses, the water level of the ballast water B in the bottom-covered steel pipe 2 gradually decreases, and the water level of the ballast water B in the bottom-covered steel pipe 2 and the height position of the upper discharge port 32c of the pumping pipe 32 (bottom). The difference from the height position of the upper end opening of the steel pipe 2 with a lid) gradually increases. Then, as shown in FIG. 4B, the ballast water B that has flowed into the pumping pipe 32 cannot be drained from the upper discharge port 32c with the discharge capacity specified in the submersible pump 31.

As described above, when the difference between the water level of the ballast water B in the steel pipe 2 with the bottom lid and the height of the upper discharge port 32c of the pumping pipe 32 cannot be dealt with by the pumping capacity specified in the submersible pump 31. The operation of the submersible pump 31 is stopped.

At this time, the ballast water B flowing in by the submersible pump 31 does not leak from the pump connection portion 32a of the pumping pipe 32 above the check valve 32b in the pumping pipe 32 due to the closing effect of the check valve 32b. , It is in a stored state.

Therefore, as shown in FIG. 4 (c), the drainage device 3 in which the ballast water B is stored in the pumping pipe 32 is pulled up from the inside of the steel pipe 2 with a bottom lid to the ground, and then ballasted from the inside of the ballast pipe 32 on the ground. Drain water B. In the present embodiment, the pumping pipe 32 is tilted and discharged from the upper discharge port 32c, but the opening / closing member 32e of the side discharge port 32d may be opened and discharged from the side discharge port 32d.

As shown in FIG. 5A, the drainage device 3 with the pumping pipe 32 emptied is installed again in the steel pipe 2 with a bottom lid, and the operation of the submersible pump 31 is restarted. Then, as shown in FIG. 5B, although the ballast water B cannot be discharged from the upper discharge port 32c of the pumping pipe 32, the ballast water B sucked up by the submersible pump 31 is stopped at the pump connection portion 32a and the check valve. It passes through the valve 32b, flows into the pumping pipe 32, and is stored.

In this way, when the amount of ballast water B corresponding to the suction capacity of the submersible pump 31 flows into the pumping pipe 32, the operation of the submersible pump 31 is stopped. Then, as shown in FIG. 5C, the drainage device 3 is pulled up from the inside of the steel pipe 2 with a bottom lid to the ground again, and the ballast water B in the pumping pipe 32 is discharged on the ground. Here, the ballast water B in the pumping pipe 32 is discharged from the side discharge port 32d with the opening / closing member 32e of the side discharge port 32d opened.

This operation is repeated until the water level of the ballast water B remaining in the steel pipe 2 with the bottom lid falls below the height that can be absorbed by the submersible pump 31. After that, as shown in FIG. 5D, a water absorbing member 4 is put into the steel pipe 2 with a bottom lid instead of the draining device 3, and a small amount of ballast water B that could not be discharged in the draining device 3 is absorbed. Allow member 4 to absorb water.

Any of the water absorbing members 4 may be adopted, but in the present embodiment, a non-woven fabric holding a polymer absorbent material having high water absorbing performance is suspended from a steel pipe 2 with a bottom lid, and ballast water B is absorbed. After letting it lift and remove it. In this way, the discharge of the ballast water B in the steel pipe 2 with the bottom lid is completed.

In this way, when the ballast water B in the bottom-covered steel pipe 2 that could not be completely drained by using the drainage device 3 is removed by using the water absorbing member 4, the inside of the bottom-covered steel pipe 2 is removed. It is possible to construct a CFT structure pillar with high quality in the filled concrete C to be cast in.

According to the liquid discharge method described above, the ballast water B in the steel pipe 2 with a bottom lid is discharged by operating the submersible pump 31 to a water level that can be pumped by the discharge capacity of the submersible pump 31, and then the submersible pump 31 is used. The ballast water B below the water level that can be pumped can be discharged by being sucked by the submersible pump 31, stored in the pumping pipe 32, and lifted and taken out from the steel pipe 2 with the bottom lid together with the pumping pipe 32.

Therefore, even if the liquid stays in the steel pipe 2 with a lid having a narrow opening and a long member length as used for the structural pillar 1, the performance of the submersible pump 31 is affected by using the drainage device 3. It is possible to quickly and easily drain the ballast water B in the covered steel pipe 2 without having to do so.

The drainage device 1 and the liquid drainage method of the present invention are not limited to the above-described embodiment, and various changes can be made without departing from the spirit of the present invention.

For example, in the present embodiment, an electromagnetic valve is provided as an opening / closing member 32e of the side discharge port 32d provided on the side surface of the pumping pipe 31, but the present invention is not necessarily limited to this, and the side discharge port 32d can be opened / closed. Any member may be adopted as long as it can be used, for example, by providing a lid material.

Further, in the present embodiment, ballast water B is taken as an example as the liquid to be discharged by the drainage device 3, but the present invention is not necessarily limited to this, and any liquid that can be sucked and discharged by the submersible pump 31 is used. For example, rainwater, muddy water, a stabilizing liquid, or the like may be used.

1 Structure Shinbashira 2 Steel pipe with bottom lid (steel pipe)
2a Bottom 2b Steel 3 Drainage device 31 Submersible pump 32 Pumping pipe 32a Pump connection 32b Check valve 32c Upper discharge port 32d Side discharge port 32e Opening and closing member 4 Water absorption member 5 Reinforcing bar cage 6 Backfill material H Underground hole P Cast-in-place pile C Filled concrete W Stabilizer B Ballast water (liquid)

Claims (3)

A submersible pump installed in an upright steel pipe with a bottom lid to suck in stagnant liquid,
A pump connection portion connected to the discharge port of the submersible pump is provided at the lower end portion, and a pumping pipe provided with an upper discharge port at the upper end portion for discharging the liquid flowing from the pump connection portion is provided.
The pumping pipe is a drainage device provided with a check valve for preventing a backflow of the liquid flowing from the pump connection portion in the vicinity of the pump connection portion. In the drainage device according to claim 1,
A drainage device characterized in that a side discharge port for discharging the liquid is provided on the side surface of the pumping pipe in the vicinity of the check valve so as to be openable and closable. A method for discharging a liquid that stays in a steel pipe in an upright posture having a bottom lid by using the drainage device according to claim 1 or 2.
A step of operating the submersible pump of the drainage device installed in the steel pipe and discharging the liquid from the upper discharge port of the pumping pipe.
When the water level of the liquid drops and the liquid is no longer discharged from the upper discharge port of the pumping pipe, the operation of the submersible pump is stopped, the drainage device is taken out from the steel pipe, and the pumping is performed by the check valve. The process of discharging the liquid stored in the pipe and
The drainage device for discharging the liquid in the pumping pipe is installed in the steel pipe in which the water level of the liquid has dropped, and the liquid is allowed to flow into the pumping pipe via the submersible pump, and then the drainage device is installed. A step of taking out from the steel pipe and discharging the liquid stored in the pumping pipe by the check valve.
A method for discharging a liquid in a steel pipe.

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