JP2017122354A - Construction method of freezing pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a freezing pipe capable of preventing the inflow-outflow of a pollutant to the inside-outside of an underground structure.SOLUTION: A first casing 3a is installed up to a bottom slab 1a being a concrete slab of an underground structure 1. In this case, the tip of the casing 3a is inserted up to the middle of a thickness of the bottom slab 1a. For example, the tip of the casing 3a is inserted into the bottom slab 1a up to this side of a part for arranging a reinforcement of the bottom slab 1a. Next, a water cutoff material 5 is filled by a predetermined quantity on the inside of the casing 3a. After solidifying the water cutoff material 5, a second casing 3b is inserted into the inside of the casing 3a. Excavation is executed up to under an underground structure 1 by penetrating the bottom slab 1a together with the water cutoff material 5 inside of the casing 3a by a casing 3b. For example, the excavation is executed up to an underground impermeable water layer by the casing 3b.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for constructing a freezing tube.

  Conventionally, there is a method of forming a frozen ground wall in the ground in order to prevent the diffusion of contaminants and the like (for example, see Patent Document 1).

JP-T-4-503402

  When constructing the frozen wall, freeze tubes are placed at predetermined intervals, frozen soil is formed around the frozen tubes, and the frozen soil around each frozen tube is connected, so that the frozen soil walls are placed within a predetermined range. Can be built.

  When using such a frozen earth wall to block the flow of groundwater to a predetermined range, for example, if there is a part where the frozen earth wall is not formed, the groundwater flows from the part beyond the frozen earth wall. For this reason, it is necessary to construct a frozen soil wall so that such a gap is not formed.

  On the other hand, structures such as cable ducts and water passages may be arranged in the ground. In such a case, if a freezing pipe is installed avoiding underground structures, it is difficult to form a continuous frozen soil wall. Therefore, it is necessary to install a freezing pipe so as to penetrate the underground structure.

  However, when there is a contaminated layer in the ground or when contaminated water is present inside the underground structure, if the freezing pipe is installed by the conventional method, the pollutant moves in and out of the underground structure. There is a fear. That is, when excavating and penetrating the underground structure, there is a possibility that contaminated water or the like flows out from the inside of the underground structure or water in the contaminated layer flows into the underground structure.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a construction method of a freezing pipe that can prevent the inflow and outflow of contaminants into and out of underground structures.

  In order to achieve the above-described object, the present invention includes a step a in which a first casing is installed on a concrete plate of an underground structure, a step b in which a water-stopping material is filled in the first casing, A step c of excavating the water-stopping material with a second casing, penetrating the concrete plate, and excavating the lower part of the underground structure; and a step of installing a freezing pipe so as to penetrate the underground structure d. and a construction method of a cryopipe.

  The concrete plate is a top plate of the underground structure, and the step a performs excavation with the first casing up to the top plate, and the step c includes a second step in the interior of the water stop material. A step e of drilling with the casing, penetrating the top plate and drilling to the bottom plate of the underground structure, a step f of filling a water-stopping material in the second casing, and the second A step g of excavating the water blocking material inside the casing with a third casing, penetrating the bottom plate, and excavating to the lower side of the underground structure.

  The concrete plate is a top plate of the underground structure, and the step a performs excavation with the first casing up to the top plate, and the step c uses the second casing to seal the waterstop material. Excavating and penetrating the top plate, step h of filling the inside of the underground structure with concrete, excavating the concrete with a third casing, and removing the bottom plate of the underground structure A step i that penetrates and digs up to a position below the underground structure.

  Each casing is preferably provided with a bid at the tip, and the bid is preferably disposed at a position that does not protrude from the outer diameter of the casing.

  The step c may be performed by filling the hole with a liquid before penetrating the concrete plate, performing a water-tight test with the liquid, and confirming that water-tightness has been secured, and then penetrating the concrete plate. .

  In the step c, a heat insulating member may be disposed on an outer periphery of the first casing or the second casing in at least a part of the underground structure or an upper portion of the underground structure.

  It is desirable that a drilled water leakage port is provided in an upper part of the second casing, and that the step c can collect and stop water during excavation of the second casing.

  According to the present invention, the water tightness of the penetration part of the concrete plate is ensured because the water stop material is filled in the first casing and the water stop material is excavated by the second casing to penetrate the concrete plate. be able to. For this reason, when excavating and penetrating underground structures, it is possible to prevent contaminated water from flowing out of the underground structures or contaminated water from flowing into the underground structures. it can.

  When the concrete plate is the top plate of the underground structure, the first plate is excavated with the first casing, and the water-stopping material inside the first casing is excavated with the second casing. By allowing the top plate to penetrate, the top plate can be penetrated while ensuring watertightness.

  When the concrete plate is the top plate of the underground structure, first, the first plate is excavated with the first casing, and the water-stopping material inside the first casing is removed by the second casing. By excavating and penetrating the top plate, the top plate can be penetrated while ensuring watertightness. Furthermore, the bottom plate of the underground structure can be penetrated while securing the water tightness by concrete inside the underground structure and excavating the concrete with the third casing to penetrate the bottom plate of the underground structure.

  Moreover, high water-tightness is securable by the bid provided in the front-end | tip of each casing being arrange | positioned in the position which does not protrude from the outer diameter of a casing.

  Moreover, before penetrating the concrete plate, water tightness can be reliably ensured by filling a liquid in the hole and conducting a water tightness test.

  Moreover, it can suppress that an underground structure and its vicinity are overcooled by arrange | positioning a heat insulation member in at least one part of the inside of an underground structure, or the upper part of an underground structure. For this reason, it can suppress that a stress is given to an underground structure by excessive cooling, and it breaks.

  In addition, by providing a drilled water leakage port in the upper part of the second casing, it is possible to collect and stop water during excavation. For this reason, it can suppress that contaminated water etc. are scattered.

  ADVANTAGE OF THE INVENTION According to this invention, the construction method of the freezing pipe | tube which can prevent the inflow and outflow of the pollutant to the inside and outside of an underground structure can be provided.

The figure which shows the process of constructing a freezing pipe. The figure which shows the process of constructing a freezing pipe. The figure which shows the bottom face of casing 3a (3b). The figure which shows the other process of constructing a freezing pipe. The figure which shows the other process of constructing a freezing pipe. The figure which shows the other process of constructing a freezing pipe. The figure which shows the other process of constructing a freezing pipe. The figure which shows the other process of constructing a freezing pipe.

  Hereinafter, the construction method of the cryopipe according to the first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 and FIG. 2 are diagrams showing a process of installing a frozen pipe 11 on the ground 2 and constructing a frozen soil wall 13. In this embodiment, the case where the underground structure 1 is opening on the ground is shown. The underground structure 1 is made of concrete, for example. A in the figure indicates the groundwater level.

  When the underground structure 1 is open to the ground, members and soil water inside the underground structure 1 are first removed. For example, in the case of a cable duct or the like, the cable is removed.

  Next, as shown to Fig.1 (a), the 1st casing 3a is installed to the bottom plate 1a which is a concrete plate of the underground structure 1. FIG. At this time, the tip of the casing 3a is inserted halfway through the thickness of the bottom plate 1a. For example, the front end of the casing 3a is inserted into the bottom slab 1a until just before the part where the reinforcing bars of the bottom slab 1a are arranged.

  Next, as shown in FIG. 1B, a predetermined amount of water-stopping material 5 is filled into the casing 3a. In addition, as the water stop material 5, it is CB (cement bentonite), for example. Further, the filling amount of the water blocking material 5 does not have to be the entire length of the casing 3a. At this time, a predetermined amount of concrete 7 may be filled inside the underground structure 1 and outside the casing 3a. Also in this case, the filling amount of the concrete 7 does not need to be filled in the entire underground structure 1.

  After the water blocking material 5 and the concrete 7 are solidified, as shown in FIG. 1C, the second casing 3b is inserted into the casing 3a. That is, the outer diameter of the casing 3b is smaller than the inner diameter of the casing 3a. By the casing 3b, the bottom plate 1a is penetrated together with the water blocking material 5 inside the casing 3a and excavated to the lower side of the underground structure 1. For example, it excavates to the underground impermeable layer with the casing 3b.

  At this time, a drilled water guide port 9 (or a drilled water leakage port) is provided in the upper part of the casing 3b. The drilling water guide port 9 is connected to a storage tank or the like (not shown). Therefore, at the time of excavation by the casing 3b, water can be collected and stopped at the time of excavation inside the underground structure 1 or below the underground structure 1.

  After excavation to a predetermined depth by the casing 3b, the freezing tube 11 is installed inside the casing 3b as shown in FIG. The casing 3b can be used as the casing of the freezing tube 11.

  FIG. 2B is a diagram showing a state in which the frozen pipes 11 are arranged at a predetermined interval and the frozen soil wall 13 is formed. The freezing pipe 11 penetrating the underground structure 1 is arranged by the method described above, and the freezing pipe 11 is installed around the underground structure 1 at a predetermined interval by a normal method. Therefore, the freezing tube 11 can also be arranged at a site where the underground structure 1 exists.

  At this time, since the water stop structure is formed in the penetrating portion of the underground structure 1, the underground water in the ground does not flow into the underground structure 1. Further, contaminated water or the like does not flow into the ground from the inside of the underground structure 1.

  FIG. 3 is a bottom view of the casings 3a and 3b. A plurality of bids 15 are arranged on the bottom surfaces of the casings 3a and 3b. Here, in order to ensure the water tightness in the excavation part by casing 3a, 3b, it is necessary to form the excavation hole by casing 3a, 3b more correctly. For this purpose, it is desirable that the bid 15 is disposed at a position that does not protrude from the outer diameter of the casings 3a and 3b. By doing in this way, a more reliable water stop structure can be formed.

  Moreover, in order to improve watertightness, it is desirable to set the number of rotations of the casings 3a and 3b to 30 rpm or less, more preferably about 15 rpm. If the number of revolutions of the excavator is increased too much, the shape of the excavation hole may be disturbed by vibration or the like, and the water tightness may be deteriorated.

  Thus, according to this embodiment, even if the underground structure 1 exists, the freezing tube 11 can be arrange | positioned. For this reason, the frozen soil wall 13 can be formed in a predetermined range so as to straddle the underground structure 1. At this time, since the water stop structure is formed in the penetrating portion of the underground structure 1, it is possible to prevent the contaminated water from flowing into and out of the underground structure 1.

  Next, a second embodiment will be described. 4-5 is a figure which shows the construction process of the freezing pipe | tube concerning 2nd Embodiment. In the following description, components having the same functions as those in the first embodiment are denoted by the same reference numerals as those in FIGS.

  In the second embodiment, the underground structure 1 is completely embedded in the ground 2. The underground structure 1 is, for example, a box culvert, and contaminated water exists inside. In this case, it is necessary to prevent the outflow of contaminated water from the inside of the underground structure 1 when installing the freezing pipe. In addition, the present invention can be similarly applied to the case where contaminated water exists outside the underground structure 1 and prevents the contaminated water from flowing into the underground structure 1.

  First, as shown to Fig.4 (a), the ground 2 is excavated by the casing 3a to the top plate 1b which is a concrete plate of the underground structure 1. FIG. At this time, the tip of the casing 3a is inserted halfway through the top plate 1b. For example, the front end of the casing 3a is inserted into the top plate 1b just before the portion where the reinforcing bars of the top plate 1b are arranged.

  Next, as shown in FIG. 4B, a predetermined amount of water-stopping material 5 is filled in the casing 3a.

  After the water blocking material 5 is solidified, the casing 3b is inserted into the casing 3a as shown in FIG. 4 (c). The first casing 3a is installed up to the bottom slab 1a of the underground structure 1 by the casing 3b. At this time, the tip of the casing 3a is inserted halfway through the thickness of the bottom plate 1a. At this time, in order to prevent the contaminated water inside the underground structure 1 from overflowing from above the casing 3b, the above-described drilled water leakage port (not shown) may be disposed.

  Next, as shown in FIG. 5A, a predetermined amount of water-stopping material 5 is filled into the casing 3b. At this time, a predetermined amount of concrete 7 may be filled inside the underground structure 1 and outside the casing 3b.

  After the water blocking material 5 and the concrete 7 are solidified, as shown in FIG. 5B, the third casing 3c is inserted into the casing 3b. That is, the outer diameter of the casing 3c is smaller than the inner diameter of the casing 3b. By the casing 3c, the bottom plate 1a is penetrated together with the water blocking material 5 inside the casing 3b and excavated to the lower side of the underground structure 1. For example, the casing 3c excavates to the underground impermeable layer. At this time, a drilled water leakage port (not shown) may be provided on the upper portion of the casing 3c.

  As shown in FIG. 3, the casing 3 c does not protrude from the outer diameter of the bid 15. Moreover, it is desirable to set the rotation speed of the casing 3c to 30 rpm or less, more preferably about 15 rpm.

  After excavation to a predetermined depth by the casing 3c, the freezing pipe 11 is installed inside the casing 3c. Thus, the construction of the freezing pipe is completed.

  According to the second embodiment, an effect similar to that of the first embodiment can be obtained. Moreover, a freezing pipe can be arrange | positioned so that the underground structure 1 embed | buried in the ground may be penetrated.

  Next, a third embodiment will be described. FIG. 6 is a diagram illustrating a construction process of a frozen tube according to the third embodiment. The third embodiment is substantially the same as the second embodiment, but differs in that the concrete 7 is filled in the underground structure 1.

  In this case, for example, after the step of FIG. 4C, the casing 3 b is pulled out once, and the inside of the underground structure 1 is filled with the concrete 7. At this time, unlike FIG. 5A, the concrete 7 is filled so that most of the underground structure 1 is buried in the cross section. In addition, the concrete 7 does not need to be filled over the full length of the underground structure 1 in the longitudinal direction. What is necessary is just to fill the concrete 7 so that most of the underground structure 1 is buried at least in the periphery where the excavation hole is formed.

  Next, the bottom plate 1a is penetrated together with the concrete 7 by the casing 3c (3b). After excavation to a predetermined depth by the casing 3c (3b), the freezing pipe 11 is installed inside the casing 3c (3b). Thus, the construction of the freezing pipe is completed.

  According to the third embodiment, the same effects as those of the second embodiment can be obtained. Moreover, since the concrete 7 is filled in the underground structure 1, when the freezing pipe 11 is installed in the casing 3c (3b) from the state of FIG. Heat can be efficiently transferred to the object 1 (and its surroundings). For this reason, the frozen ground wall 13 can be efficiently formed around the underground structure 1.

  Next, a fourth embodiment will be described. FIG. 7 is a diagram illustrating a construction process of a freezing tube according to the fourth embodiment. The fourth embodiment is substantially the same as the second embodiment, but differs in that a heat insulating member 17 is disposed on the outer periphery of the casing 3b.

  In the present embodiment, in the process of FIG. 4C described above, the heat insulating member 17 is provided on the outer periphery of the casing 3b at a portion located inside the underground structure 1 or a portion located above the underground structure 1. Be placed. The heat insulating member 17 is a general heat insulating material such as polyethylene foam. The heat insulating member 17 is made, for example, in half, and is arranged so as to cover the outer periphery of the casing 3b.

  In addition, when arrange | positioning the heat insulation member 17 in the upper part of the underground structure 1, you may arrange | position the heat insulation member 17 in the outer periphery of the casing 3a. Moreover, the heat insulation member 17 does not need to be arranged in the entire range of the inside and the upper part of the underground structure 1. What is necessary is just to arrange | position to at least one part.

  By disposing the heat insulating member 17, when the frozen pipe 11 is disposed in the casing 3b (casing 3c) and the frozen soil wall is formed, the underground structure 1 and the ground 2 above it are prevented from being excessively cooled. can do. For example, when the underground structure 1 is excessively cooled, there is a possibility that a crack or the like is partially generated due to thermal stress. When the underground structure 1 is damaged in this manner, the contaminated water inside may flow out.

  Similarly, when frozen soil is formed above the underground structure 1, stress is applied to the underground structure 1 by the frozen soil, and the underground structure 1 may be damaged. For this reason, the heat insulation member 17 is arrange | positioned as needed so that an excessive stress may not be added to the underground structure 1. FIG.

  If the frozen ground wall 13 is formed below the underground structure 1, a continuous frozen ground wall 13 can be formed as shown in FIG. At this time, in order to reliably dam the groundwater above the underground structure 1, a chemical solution injection or the like may be separately performed.

  According to the fourth embodiment, the same effect as that of the second embodiment can be obtained. Moreover, since it can suppress that the underground structure 1 and its upper part are cooled excessively, it can suppress that the underground structure 1 is damaged by excessive cooling.

  Next, a fifth embodiment will be described. FIG. 8 is a diagram illustrating a construction process of a freezing tube according to the fifth embodiment. The fifth embodiment is substantially the same as the second embodiment, but differs in that a watertight test is performed before the concrete plate of the underground structure 1 is penetrated.

  Fig.8 (a) is a figure which shows the process of performing a water-tight test between FIG.4 (b) and FIG.4 (c). For example, before the water blocking material 5 in the casing 3a is excavated with the casing 3b and the top plate 1b is penetrated, the casing 3b is extracted, and the excavation hole is filled with the liquid 19 (for example, water), and a watertight test is performed. In the watertight test, the liquid 19 is left for a predetermined time in a state where the liquid 19 is filled, and the presence or absence of water leakage is determined by a change in the water level.

  After the watertight test confirms that there is no water leakage, the liquid 19 is removed and the top plate 1b is penetrated by the casing 3b. By doing in this way, the inflow and outflow of contaminated water to the inside and outside of the underground structure 1 can be prevented.

  Similarly, FIG. 8B is a diagram illustrating a process of performing a watertight test between FIG. 5A and FIG. In this case, the water blocking material 5 in the casing 3b is excavated by the casing 3c, and the casing 3c is extracted before penetrating the bottom plate 1a, the excavation hole is filled with the liquid 19 (for example, water), and a watertight test is performed. .

  According to the fifth embodiment, the same effect as that of the second embodiment can be obtained. Moreover, when penetrating the concrete plate of the underground structure 1, it is possible to confirm that the water-stopping property is ensured by performing a watertight test in advance.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, the shape of the underground structure 1 is not limited to the illustrated example, and the shape may be any shape other than a rectangle, such as a circle or a semicircle.

1 ……… Underground structure 1a ……… Bottom plate 1b ……… Top plate 2 ……… Ground 3a, 3b, 3c ……… Case 5 ……… Waterproof material 7 ……… Concrete 9 ……… Shaving Perforated water induction port 11 ......... Freezing pipe 13 ......... Frozen earth wall 15 ......... Bid 17 ......... Heat insulation member 19 ......... Liquid

Claims (7)

A step of installing a first casing on a concrete plate of an underground structure;
Filling the inside of the first casing with a waterstop material b;
C) excavating the water blocking material with a second casing, penetrating the concrete plate, and excavating the lower part of the underground structure;
Installing a freezing pipe so as to penetrate the underground structure; and
The construction method of the freezing pipe characterized by comprising. The concrete plate is a top plate of the underground structure,
The step a performs excavation in the first casing up to the top plate,
The step c includes
A step e of excavating the water blocking material by a second casing, penetrating the top plate, and excavating to the bottom plate of the underground structure;
Filling the inside of the second casing with a waterstop material; and
A step g of excavating the water-stopping material inside the second casing with a third casing, penetrating the bottom plate, and excavating the lower part of the underground structure;
The method for constructing a cryopipe according to claim 1, comprising: The concrete plate is a top plate of the underground structure,
The step a performs excavation in the first casing up to the top plate,
The step c includes
Excavating the water blocking material with a second casing and penetrating the top plate; and
Filling the inside of the underground structure with concrete h,
Excavating the concrete with a third casing, penetrating a bottom slab of the underground structure, and excavating to a lower part of the underground structure; and
The method for constructing a cryopipe according to claim 1, comprising:   The construction of the freezing pipe according to any one of claims 1 to 3, wherein each casing is provided with a bid at a tip, and the bid is disposed at a position not protruding from an outer diameter of the casing. Method. The step c includes
The liquid is filled in the hole before penetrating the concrete plate, the water tightness test is performed with the liquid, and after confirming that the water tightness is secured, the concrete plate is penetrated. The construction method of the freezing pipe | tube in any one of Claim 4. The step c includes
The heat insulating member is arranged on an outer periphery of the first casing or the second casing in at least a part of the underground structure or the upper part of the underground structure. Item 6. The method for constructing a cryopipe according to any one of items 5 to 9. A drilled water leak opening is provided at the top of the second casing;
The step c includes
The method for constructing a frozen pipe according to any one of claims 1 to 6, wherein water can be collected and stopped when the second casing is excavated.

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