JP6481963B2 - Freezing and water stop method - Google Patents

Description

  The present invention relates to a freeze-stop method. More specifically, the present invention relates to a method of charging water through a medium- and small-diameter pipe and freezing water without excavating a closed area where water flows.

  As a countermeasure against inflow of groundwater due to loosening of the sewer pipe joints and cracks in the sewer pipe, direct repair is possible for large-diameter pipes, but for small and medium-diameter pipes, repairs are made by a special method. There is a need to do. An example of this method is a packer method. This construction method is a method in which the front and rear of the defective part are closed, liquid is injected into the closed section after being made into an independent space, and cracks, joints, etc. are filled with a solidified product finally formed by the injected liquid. is there. In addition, this method is also suitable for sites where the inundated water is deep, such as underground tunnels, where it cannot be reached, and where the ground is loose, such as depressions.

  A grout material is generally used as a packing material for the packer method. However, the grout material is heavy and therefore has poor workability and is completely solidified, so that it cannot be recovered in the unlikely event. Furthermore, the grout material may crack over time. In addition, pipes and non-stretchable cloths are used as the material for forming the space in the packer method. However, these are bulky and difficult to carry or the work may be difficult due to their fixed shape.

  In addition, when performing construction such as branching of a pipe or replacement / expansion of a valve, it is possible to shorten the time of draining / water filling without shortening the water draining time without shortening the water. The freezing and water stop method that can be used for plumbing work is mentioned. This method is a method in which water in a pipe is cooled and frozen using liquid nitrogen or liquefied carbon dioxide gas at an appropriate position, thereby generating ice pillars in the pipe and acting as a valve to stop the water. However, the freeze-stop method is an absolute condition that there is no flow of water, and therefore cannot be used when there is a flow of water.

  Furthermore, a method of using a water-absorbing sandbag or the like has been proposed as a countermeasure against flooding or flooding or removal of accumulated water (see Patent Document 1). However, the water-absorbing soil is heavy and inconvenient to carry, has poor workability, and has a problem that a large amount of storage is required because the amount of water absorption is limited. In addition, in the case of water stoppage at an unreachable location such as an underground tunnel, the sandbag is bulky and therefore it is difficult to enter from a narrow location.

JP 2007-092486 A

  The present invention has been made in view of the above-mentioned conventional problems, and it is easy to collect and carry the material, can be introduced through a small-diameter pipe, and can be put into a closed region where water flows in a short time. It is an object of the present invention to provide a freeze-stop method that can freeze-stop.

  In order to solve the above-mentioned problems, the present inventors have intensively studied, and as a result, focused on a polymer water-absorbing material that is lightweight, has a large amount of water absorption, and has a high water absorption rate. After being put in and put in, the polymer water-absorbing material is formed as a filling member containing water absorbed, and the knowledge can be solved by freezing it, and the present invention has been achieved.

That is, the present invention introduces a water-permeable and stretchable bag body containing a polymer water-absorbing material powder into a target location in a closed region where water flows through a medium- and small-diameter pipe. Provided is a frozen water-stopping method characterized in that a molecular water-absorbing material is a filling member containing water absorbed, and the wall is formed by stacking them, and then the wall is frozen to form a water-stop wall. It is.
According to this configuration, it can be put in through a medium- and small-diameter pipe, and since the absorbed polymer water-absorbing material does not fall apart, it can be a stackable filling member. The polymer water-absorbing material absorbs water through the bag body and swells, and freely deforms with the bag body according to the surrounding shape, so it can be used in a complex shaped region and has a high water absorption speed. Since water is absorbed in a short time, the work time until freezing is short. The construction period is short because there is no need to cut.

  In the freeze-stop method of the present invention, it is preferable to attach or incorporate a heavy article in a water-permeable and stretchable bag containing a polymer water-absorbing material. According to this configuration, the bag body not only reliably passes through the small and medium diameter pipes in a short time, but also easily absorbs water at a target place even in an area where water flows. Moreover, it becomes possible to accelerate the freezing rate by incorporating a material having high thermal conductivity such as iron sand as a heavy object.

  Moreover, in the freezing and water stopping method of this invention, it is preferable that a water-permeable and elastic | stretch bag body is cylindrical shape. With this configuration, even if the bag body is in a small and medium diameter pipe having an inner diameter of about 30 mmφ, not only can the bag be surely passed, but various sizes can be used depending on the diameter and length of the pipe. Thereby, since the filling members having different sizes are formed, they can be easily stacked.

  Further, in the freeze-stop method of the present invention, the polymer water-absorbing material powder may be introduced before and / or after the introduction of the water-permeable and stretchable bag containing the polymer water-absorbing material. . With this configuration, the polymer water-absorbing material can be introduced into a narrow space in which the bag body cannot enter and a space between the bag body and the bag body.

  Moreover, in the freezing and water stopping method of this invention, it is preferable to inject | pour liquid nitrogen and to freeze the said filling member. With this configuration, the water absorbed by the polymer water-absorbing material can be frozen and stopped in a short time. Since the injection nozzle can be passed through the small and medium diameter pipe, the injection work is also easy. Since it is a liquid, it can also be injected into the gaps in the structure.

  According to the present invention, the water-permeable and stretchable bag body incorporating the polymer water-absorbing material powder is easy to carry and can be introduced through a medium- and small-diameter pipe, and the polymer water-absorbing material that has absorbed and swelled water. Since the material is freely deformed and functions as a water flow inhibiting material, it is possible to freeze and stop the water in a short time even in a closed region where there is a flow of water in which a complex shaped structure exists. Even in the unlikely event, the polymer water-absorbing material used in the freeze-stopping can be collected together with the bag body, so that the collection is easy.

  Hereinafter, the freeze-stop method according to the present invention will be described in detail.

  The polymer water-absorbing material that can be applied to the present invention absorbs water and swells several times to nearly 1000 times when it is brought into contact with water, but does not dissolve in water. For example, cross-linked sodium polyacrylate, cross-linked starch and sodium acrylate graft copolymer, starch and acrylonitrile or hydrolyzate of starch and methacrylate graft copolymer, sodium polyacrylate and polyacrylamide copolymer, Anionic properties such as partially hydrolyzed polyacrylonitrile or vinyl ester and ethylenically unsaturated carboxylic acid copolymer, copolymer of isobutylene and maleic anhydride, modified polyacrylic crosslinked product; crosslinked polyalkylene oxide, polystyrene oxide Nonionic polymer water-absorbing materials such as polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide and carboxymethyl cellulose. These polymer water-absorbing materials can be used singly or in combination of two or more. Of these, cross-linked sodium polyacrylate and a modified product thereof are preferred because of their excellent water absorption.

  The polymer water-absorbing material powder preferably has an average particle size of 100 μm to 1,000 μm, particularly preferably 100 μm to 500 μm. If the average particle size is too small, it will be easy to leak from the hole (gap) of the bag, while if the average particle size is too large, it will be difficult to enter the gap between structures such as cable trays and piping parts. There is concern that the water effect will be hindered. If the average particle diameter is 500 μm or less, the polymer water-absorbing material that has absorbed water and swelled to increase the volume easily enters the gaps in the structure, so that the water-stopping effect can be enhanced. When the salt concentration of the water at the input place is high, the water absorption swelling ability of the polymer water absorbent material is extremely reduced, and the particles do not swell to the expected size and it is difficult to form a water blocking wall. May be selected as appropriate depending on the inner diameter of the tube and the shape of the structure. In addition, the polymer water-absorbing material is poured into water in a state of being incorporated in the bag, and then absorbs water to become a filling member containing moisture, and these filling members are stacked to form a wall. Those having a water absorption ratio under pressure of 20 g / g or more are preferred.

  As the water-permeable and stretchable bag, for example, a woven or knitted fabric or a nonwoven fabric using a synthetic fiber such as nylon or polyester as a material is preferable in terms of excellent water resistance and strength. Among them, the knitted fabric has a uniform size of the hole of the bag and is highly stretchable. Examples of the knitting structure include flat knitting, rubber knitting, and pearl knitting, and are not particularly limited. The bag body is made of synthetic fiber wooly yarn, woven or knitted fabric using elastic yarn such as covering yarn with spandex wrapped with nylon yarn or polyester yarn, elastic nonwoven fabric, elastic film with holes, etc. It may be formed of a water-permeable stretchable material. The shape and size of the bag body is arbitrary, and for example, a cylindrical shape having a diameter of 3 to 20 cm and a length of about 20 to 50 cm in a non-stretched state is preferable. The size of the hole of the water-permeable and stretchable bag is not particularly limited, but is preferably smaller than the average particle diameter of the polymer water-absorbing material from the viewpoint of preventing leakage.

  It is preferable that the length of the small and medium diameter pipe is appropriately designed according to the depth of the destination place in the underground area. Moreover, it is good to install the pipe | tube of medium and small diameter on the ground above the place which is going to form a water stop wall. Although there is no restriction | limiting in the installation number of the pipe | tube of medium and small diameter, For example, it is desirable to install two or more by 30-50 intervals.

  For example, when a water-permeable and stretchable bag containing the polymer water-absorbing material powder is introduced from the entrance of a pipe having a length of 50 to 400 cm, the bag reaches the target location in the region where the water flows. However, since the bag body is water-permeable and stretchable, the polymer water-absorbing material absorbs water and swells to form a round filling member. At this time, a water-permeable and stretchable bag containing a polymer water-absorbing material is fitted with or contains a material having a high specific gravity such as gravel, crushed stone pieces, iron pieces, concrete pieces, iron sand, copper pieces, and brass pieces. When the bag body passes through the pipe and reaches the area where the water flow is, the filling member is easily stopped at the destination without being affected by the water flow, and the filling members are stacked to form a wall. It becomes easy to let. Moreover, if the size of the water-permeable and stretchable bag containing the polymer water-absorbing material powder is varied, it can be easily stacked.

  In order to completely stop water gaps between filling members and narrow gaps in structures such as cable trays and pipes existing in the area, only the polymer water absorbent powder is passed through the small and medium diameter pipes. Can be thrown in. The charging time is not particularly limited, and it is preferable to load before and after the bag is loaded.

  After charging the polymer water-absorbing material, it varies slightly depending on the type and temperature of the polymer water-absorbing material. It takes on the aspect of a filling member containing moisture absorbed by water. They are sequentially stacked to form a wall. In order to freeze the wall, a coolant such as liquid nitrogen or liquefied carbon dioxide, which can be injected through a small-diameter pipe and has a high freezing rate, is preferably injected using a nozzle. The injection is preferably carried out towards the wall formed by the filling member. A frozen soil wall can be formed by freezing the filling member.

  Among the coolants, liquid nitrogen is a liquid and is preferable in that it can be injected into various places. If sand iron, copper pieces, brass pieces, or the like are incorporated in the bag body, it becomes a cooling aid and can be more efficiently frozen in a short time.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited only to a following example.

Example 1
A preliminary test was conducted using a commercially available nylon stocking as a water-permeable and stretchable material. A bag body 10 cm in diameter and 15 cm in length with a cylindrical lower end tied with a string is filled with 10 g of commercially available cross-linked sodium polyacrylate (average particle diameter of about 500 μm, water absorption of 350 g per gram), and the length is about One 5 cm nail was placed, the upper end was tied with a string, and a bag body filled with a polymer water-absorbing material and a heavy article was produced.
The produced bag was passed through a metal tube having an inner diameter of 30 mmφ and a length of 50 cm into a container containing 10 L of water (water temperature 20 ° C.). As a result, about 5 minutes after the addition, the polymer water-absorbing material swelled about 200 times (volume) and exhibited the appearance of a filling member.

  Next, liquid nitrogen was injected into the water surface from a liquid nitrogen cylinder through a nozzle while stirring water. As a result, in any case, it was confirmed that the ice including the polymer water-absorbing material stretched 20 minutes after the injection, and freezing water stoppage was possible.

(Example 2)
Ten bags filled with the same polymeric water-absorbing material and heavy material as in Example 1 were prepared. The produced bag was passed through a metal tube having an inner diameter of 30 mmφ and a length of 50 cm into a vat containing 50 L of water (water temperature 20 ° C.) in order. As a result, the polymer water-absorbing material swelled about 200 times (volume) in about 5 minutes after the addition, and 10 filling members were laminated in order from the bottom of the bat.

(Comparative Example 1)
A bag body in which the lower end of a cotton material having the same size and shape as that used in Example 1 is tied with a string is filled with 10 g of the crosslinked sodium polyacrylate used in Example 1, and further a nail having a length of about 5 cm. 1 was put, the upper end was tied with a string, and the bag body which filled the polymer water absorbing material and the weight part was produced.
The produced bag was put into 2 L of water (water temperature 20 ° C.) through the same metal tube as in Example 1. As a result, since the bag itself was water permeable but not stretchable, the polymer water-absorbing material swelled, but did not exhibit the aspect of a filling member.

  The freeze-stop method of the present invention can reduce the construction period because the intrusion water can be stopped without cutting. Moreover, since liquid nitrogen etc. are liquid, it can be inject | poured into various places. According to this method, freezing water can be stopped even at locations where construction cannot be performed by running water.

Claims (5)

  A water-permeable and stretchable bag containing the polymer water-absorbing material powder is introduced into a target location in a closed area where water flows through a small and medium-sized pipe, and the polymer water-absorbing material absorbs water. A freezing / water-stopping method comprising forming a water-containing filling member, stacking them to form a wall, and then freezing the wall to form a water-stopping wall.   The freeze water-stopping method according to claim 1, wherein a heavy article is attached to or built in a water-permeable and stretchable bag body in which a polymer water-absorbing material is incorporated.   The freeze-stop method according to claim 1 or 2, wherein the water-permeable and stretchable bag body has a cylindrical shape.   The freeze-stop method according to any one of claims 1 to 3, wherein the polymer water-absorbing material powder is introduced before and / or after the water-permeable and stretchable bag containing the polymer water-absorbing material is introduced. .   The freeze-stop method according to claim 1, wherein liquid nitrogen is injected to freeze the filling member.