JP2011161368A - Method for constructing permeable reactive barrier and guide member used in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To change the side surface shape of a permeable reactive barrier formed of a cleaning material, as desired. <P>SOLUTION: In this construction method, the permeable reactive barrier 27 is constructed by arranging a plurality of permeable reactive barrier parts 25 contiguously in the ground 2 by repeating the process of inserting a cylindrical casing 10 into the ground 2, removing soil 3 in the casing 10 and then refilling the inside of the casing 10 with the cleaning material 4 to provide the columnar permeable reactive barrier part 25 in the ground 2. When the inside of the casing 10 is refilled with the cleaning material 4, the inside of the casing 10 is partitioned into a plurality of areas with one or more guide plates 16, and the areas separated by the guide plates 16 are refilled with the cleaning material 4. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a construction method for a permeation reaction wall installed on a flow path of groundwater and a guide member used therefor for the purpose of purifying contaminated groundwater or preventing diffusion.

  For example, when groundwater is polluted by chemical substances discharged from a factory or by leaking to the surrounding ground and penetrating underground, the flow of groundwater Construction to construct a permeation reaction wall on the road will be carried out. A permeation | transmission reaction wall is comprised with the removal material which removes the chemical substance contained in groundwater, and the purification material which consists of a support material which carry | supports this and ensures water permeability. The permeation reaction wall is constructed on the contaminated groundwater flow path, and when contaminated groundwater enters the permeation reaction wall from the contact surface and permeates through it, the removal material and the chemical substance that is the contaminant come into contact with each other, and adsorption and decomposition A chemical substance is removed by a chemical action such as (Patent Document 1).

  As the construction method of the permeation reaction wall, a construction method disclosed in Patent Document 2 is known. As shown in FIG. 1, a circular excavation casing 1 is first inserted vertically into the ground 2. Then, the soil 3 in the casing 1 is excavated and removed. Next, as shown in FIG. 2, the purification material 4 is introduced into the emptied casing 1 and backfilled. Thereafter, when the casing 1 is extracted from the ground 2, a columnar permeation reaction wall portion 5 made of the purification material 4 is formed in the ground 2 as shown in FIG. 3. Next, as shown in FIG. 4, the next columnar permeation reaction wall portion 5 is formed by the same process adjacent to the columnar permeation reaction wall portion 5 thus formed. By repeatedly performing the step of providing the columnar permeation reaction wall portion 5 in this way, a plurality of permeation reaction wall portions 5 are formed adjacent to each other in the ground 2, and the permeation reaction wall 6 made of the purification material 4 is formed. Are constructed in the ground 2 continuously.

  Then, as shown in FIG. 5, a permeation reaction wall 6 made of the purification material 4 is continuously formed in the ground 2 so as to be orthogonal to the flow path of the groundwater 7, and the contaminated groundwater 7 is transmitted to the permeation reaction wall 6. Let Thus, when the groundwater 7 permeates the permeation reaction wall 6, the removal material and the chemical substance that is the pollutant come into contact with each other, and harmful chemical substances contained in the groundwater 7 are removed by a chemical action such as adsorption or decomposition. is there.

Japanese Patent No. 3516613 Japanese Patent Laid-Open No. 2003-10832

  However, the side surface of the permeation reaction wall formed by arranging the columnar permeation reaction wall portions is not flat, and as shown in FIG. 5, it has a wavy shape in which a part of the cylinder is repeated. For this reason, the thickness of the permeation reaction wall is not constant, and the thick and thin portions are alternately changed along the continuous direction of the permeation reaction wall. As a result, when the groundwater 7 permeates the permeation reaction wall 6, the permeation time is different between the thick part and the thin part, and a sufficient part and an insufficient part of the chemical action are generated. In addition, in order to obtain a sufficient chemical action even in a thin part, an excessive amount of purification material is used in a thick part, which hinders cost reduction.

  An object of the present invention is to enable the side shape of the permeation reaction wall made of a purification material to be changed as desired.

  In order to achieve this object, according to the present invention, a cylindrical casing is inserted into the ground, the soil in the casing is removed, and then the purification material is backfilled in the casing, so that a column-shaped permeation in the ground. A method of constructing a permeation reaction wall by adjoining a plurality of permeation reaction wall portions in the ground by repeatedly performing the step of providing the reaction wall portion, and when refilling the purification material in the casing, 1 or Provided is a permeation reaction wall construction method characterized in that the inside of a casing is divided into a plurality of regions using two or more guide plates, and the purification material is backfilled in the regions divided by the guide plates.

  In this construction method, the guide plate may be installed in the casing in parallel with the extending direction of the permeation reaction wall. In the casing, two guide plates may be installed parallel to each other with a gap between them, and the purification material may be backfilled in a region between the two guide plates. Alternatively, in the casing, three or more guide plates are installed parallel to each other with a gap therebetween, and different purification is performed in a region between any two guide plates and a region between any other two guide plates. The material may be backfilled.

  Further, according to the present invention, the step of providing a columnar permeation reaction wall portion in the ground by inserting the cylindrical casing into the ground, removing the soil in the casing, and then backfilling the purification material in the casing. A guide member used for the above-mentioned invention, comprising a plurality of guide plates that divide the inside of the casing, and a support portion that supports the plurality of guide plates in parallel with each other with a gap therebetween. The

  According to the present invention, since the inside of the casing is divided by the guide plate and then the purification material is backfilled, the shape of the backfilling of the purification material can be shaped by the arrangement of the guide plate, and the permeation reaction wall made of the purification material The side surface shape can be changed as desired. For example, if a guide plate is installed in the casing in parallel with the extension direction of the permeation reaction wall, the side surface of the permeation reaction wall becomes a plane perpendicular to the permeation direction of groundwater, and the side shape of the permeation reaction wall is made flat. Can do. Then, by changing the side shape of the permeation reaction wall as desired and making the thickness of the permeation reaction wall constant, the contact time between the groundwater and the purification material at the permeation position is made equal, and the chemical action of the purification material on the groundwater Can be stabilized. Moreover, the usage-amount of a purification material can be reduced.

It is explanatory drawing of background art, and shows the state which inserts a casing in the ground. It is explanatory drawing of background art, and shows the state which backfills a purification material in a casing. It is explanatory drawing of background art, and shows the column-shaped permeation | transmission reaction wall part formed in the ground. It is explanatory drawing of background art, and shows the state which forms the next permeation | transmission reaction wall part adjacent to a cylindrical permeation | transmission reaction wall part. It is explanatory drawing of the permeation | transmission reaction wall constructed | assembled in background art. It is explanatory drawing of a cylindrical casing. It is explanatory drawing of the state which lifted the casing with the crane. It is explanatory drawing of the state which inserted the casing in the ground. It is a perspective view of a guide member concerning an embodiment of the invention. FIG. 10A is a plan view, FIG. 10B is a side view, and FIG. 10C is a front view of the guide member shown in FIG. 9. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning embodiment of this invention, and shows the state which inserts a casing in the ground. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning embodiment of this invention, and shows the state which inserted the guide member in the casing. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning embodiment of this invention, and shows the state which backfills a purification material in the area | region divided by the guide member in the casing. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning embodiment of this invention, and shows the permeation | transmission reaction wall part formed in the ground. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning embodiment of this invention, and shows the state which forms the next permeation | transmission reaction wall part adjacent to the permeation | transmission reaction wall part formed previously. It is explanatory drawing of the permeation | transmission reaction wall constructed | assembled by the permeation | transmission reaction wall construction method concerning embodiment of this invention. It is a perspective view of the guide member using H-section steel. FIG. 18A is a plan view, FIG. 18B is a side view, and FIG. 18C is a front view of the guide member shown in FIG. 17. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning other embodiment of this invention, and shows the state which inserted the guide member using H-section steel in the casing. It is explanatory drawing of the permeation | transmission reaction wall constructed | assembled using the guide member using H-section steel. It is a perspective view of a guide member provided with three guide plates. It is (a) top view, (b) side view, (c) front view of the guide member shown in FIG. It is explanatory drawing of the permeation | transmission reaction wall construction method concerning other embodiment of this invention, and shows the state which inserted the guide member provided with the three guide plates in the casing. It is explanatory drawing of the permeation | transmission reaction wall constructed | assembled using the guide member provided with three guide plates.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 6, the casing 10 has a hollow cylindrical shape with both upper and lower ends opened. The casing 10 is, for example, a steel pipe having a diameter of 3000 mm and a length of 5 m. When forming the permeation reaction wall deeply, it is preferable to use a casing 10 in which a plurality of steel pipes are arranged in series.

  As shown in FIG. 7, an excavator 11 such as a hammer grab is attached to the upper end of a casing 10 that stands vertically on the ground 2, and the casing 10 is suspended by a crane 12. As shown in FIG. 8, the casing 10 is vertically inserted into the ground 2 by lowering the casing 10 suspended by the crane 12.

  As shown in FIGS. 9 and 10, the guide member 15 according to the embodiment of the present invention includes two guide plates 16 and 16 made of rectangular steel plates that are long in the vertical direction, and the two guide plates 16 and 16. The support part 17 which supports is provided. The support portion 17 is made of steel bar or the like having an appropriate length, and is disposed at a location above and below the guide member 15. The two guide plates 16 and 16 are supported in parallel with each other with a predetermined gap.

  The guide member 15 has the same length (depth) as the casing 10. The guide member 15 has a size that can be inserted into the casing 10.

  Next, the permeation reaction wall construction method according to the embodiment of the present invention will be described. First, the casing 10 is conveyed to an arbitrary position by the crane 12. Then, as shown in FIG. 11, the casing 10 is inserted vertically into the ground 2. The casing 10 is inserted into the ground 2 by lowering the casing 10 suspended by the crane 12 as described with reference to FIG. When the casing 10 is inserted into the ground 2, the casing 10 may be rotated.

  After the casing 10 is inserted into the ground 2, the soil 3 in the casing 10 is excavated by the excavator 11 and removed. In this case, the soil 3 in the casing 10 can be excavated and removed by an auger screw or the like provided in the excavator 11.

  Next, as shown in FIG. 12, the guide member 15 is inserted into the emptied casing 10. Thus, by inserting the guide member 15 into the casing 10, the inside of the casing 10 is sandwiched between one region 20 (the inner surface of the guide plates 16, 16) located between the two guide plates 16, 16. Area 20) and two areas 21 and 21 located outside the two guide plates 16 (two areas 21 and 21 surrounded by the outer surface of the guide plate 16 and the inner surface of the casing 10). It becomes a state.

  That is, as shown in FIG. 12, when the guide member 15 is inserted into the casing 10, the two guides constituting the guide member 15 are arranged so that both sides of the guide plates 16 and 16 are just close to the inner surface of the casing 10. The distance between the plates 16 and 16 and the width of the guide plates 16 and 16 are designed.

  Further, when the guide member 15 is inserted into the casing 10, the guide plates 16 and 16 are installed so as to be parallel to the extension direction of the permeation reaction wall 27 described later.

  Then, as shown in FIG. 13, the purification material is divided into the region 20 (region 20 sandwiched between the inner surfaces of the guide plates 16, 16) thus divided between the two guide plates 16, 16 in the casing 10. Insert 4 and backfill. In addition, the purification material 4 is comprised by the removal material which decomposes | disassembles or adsorbs and removes the chemical substance contained in the contaminated ground water, and the support material which retains removal materials, such as a crushed stone, and ensures water permeability.

  In the casing 10, two regions 21 and 21 (two regions 21 and 21 surrounded by the outer surface of the guide plate 16 and the inner surface of the casing 10) divided on the outer sides of the two guide plates 16 include: Instead of the purification material 4, a water-permeable backfill material 22 is introduced and backfilled. In this case, crushed stone or the like is used for the backfill material 22. Further, the soil 3 excavated on site may be used as the backfill material 22. The backfilling of the purification material 4 and the backfilling material 22 is performed using, for example, a backhoe.

  Thereafter, the casing 10 and the guide member 15 are extracted upward from the ground 2 by being lifted by the crane 12. Thereby, as shown in FIG. 14, a columnar permeation reaction wall portion 25 made of the purification material 4 is formed in the ground 2. As described above, since the purification material 4 is backfilled in the region 20 (the region 20 sandwiched between the inner surfaces of the guide plates 16 and 16) divided by the two guide plates 16 and 16 in the casing 10, in this way. The formed permeation reaction wall portion 25 has a flat shape in which a pair of parallel planes 26 and 26 are formed on both sides of a cylindrical shape. In this case, in the casing 10, the guide plates 16, 16 are installed so as to be parallel to the extension direction of the permeation reaction wall 27 described later. The planes 26 and 26 are both parallel to the extension direction of the permeation reaction wall 27 described later.

  Next, as shown in FIG. 15, the next permeation reaction wall portion 25 is formed by the same process adjacent to the flat columnar permeation reaction wall portion 25 thus formed. Thus, also when forming the next permeation | transmission reaction wall part 25, the guide plates 16 and 16 are installed so that it may become parallel to the extension direction of the permeation | transmission reaction wall 27 mentioned later. By forming the next permeation reaction wall portion 25 adjacent to the already formed flat columnar permeation reaction wall portion 25 in this way, the planes 26 and 26 of the permeation reaction wall portion 25 already formed and the next permeation reaction wall portion. The 25 planes 26 and 26 are parallel to the extension direction of the permeation reaction wall 27 described later, and the planes 26 and 26 of the two adjacent permeation reaction wall portions 25 are aligned on the same plane.

  In this way, by repeating the step of sequentially providing the flat columnar permeation reaction wall portions 25 adjacent to each other, the plurality of permeation reaction wall portions 25 are arranged adjacent to each other in the ground 2 while aligning the flat surfaces 26 and 26 on the same plane. As shown in FIG. 16, the permeation reaction wall 27 made of the purification material 4 is continuously constructed in the ground 2. In this case, the steps described in FIGS. 11 to 15 are performed as many times as necessary, and the permeation reaction wall 27 is expanded to the necessary scale.

  The permeation reaction wall 27 thus created has a flat wall surface, and the thickness of the permeation reaction wall 27 is constant over the extending direction of the permeation reaction wall 27. Then, by constructing the permeation reaction wall 27 having a constant thickness so as to be orthogonal to the permeation direction of the groundwater, when the groundwater 7 permeates the permeation reaction wall 6, the removal material 4 and the chemical that is a contaminant Substances come into contact with each other, and harmful chemical substances contained in the groundwater 7 are removed by chemical action such as adsorption and decomposition. Since the permeation reaction wall 27 has a constant thickness, even if the permeation position of the groundwater 7 changes, the contact time between the removal material 4 and the groundwater 7 is the same, and there is no difference in removal performance depending on the location. It is possible to stabilize the chemical action of the purification material 4 against the above. And the quantity of the purification | cleaning material 4 can be reduced compared with the existing construction method by making the thickness of the permeation | transmission reaction wall 27 into the minimum necessary over the whole.

  Moreover, the construction method of the present invention can be easily transferred to the permeation reaction wall construction method using the existing casing 10. Therefore, it is easy to review the process and the like, and it is possible to divert existing equipment, so that an effect can be obtained at low cost.

  As mentioned above, although an example of embodiment of this invention was demonstrated, this invention is not limited to the above form. For example, as shown in FIGS. 17 and 18, a guide member 30 using H-section steel can be used. In this case, the H-shaped steel flange can be the two guide plates 31, 31, and the H-shaped steel web can be the support portion 32.

  Moreover, when using H-section steel, it is preferable to attach the auxiliary | assistant board 33 to the side edge of the guide plates 31 and 31 (H-section steel flange) as needed. By extending the width of the guide plates 31 and 31 to an arbitrary length with the auxiliary plate 33, as shown in FIG. 19, when the guide member 30 is inserted into the casing 10, the guide plate 31 (auxiliary plate 33). Both sides of the casing 10 are brought close to the inner surface of the casing 10, and the inside of the casing 10 is divided into a region 20 between the two guide plates 31, 31 and two regions 21, 21 positioned outside the two guide plates 31. And can be divided into

  And the inside of the casing 10 is divided into the area | region 20 between the two guide plates 31 and 31 and the area | regions 21 and 21 outside each of the two guide plates 31 by the guide member 30 using H-shaped steel. Accordingly, the steps described above with reference to FIGS. 11 to 15 can be performed as many times as necessary, and the permeation reaction wall 27 shown in FIG. 16 can be similarly constructed.

  In addition, when the inside of the casing 10 is divided by the guide member 30 using the H-shaped steel as described above, the region 20 between the two guide plates 31 and 31 has a support portion 32 (an H-shaped steel web). Thus, the left and right region portions 20a and 20b are further divided. Therefore, the removal material 4 is put into one of the two region portions 20a and 20b (for example, the region portion 20a) divided by the support portion 32 to be backfilled, and the other (for example, the region portion 20b) is backfilled with water shielding. By using the material 35 and backfilling it, the amount of the purification material 4 used can be reduced.

  In this case, as shown in FIG. 20, a permeation reaction wall 36 is constructed in which the portion backfilled with the removal material 4 and the portion backfilled with the water-impervious backfill material 35 are alternately continued. In the permeation reaction wall 36, the groundwater 7 bypasses the portion backfilled with the water-impervious backfilling material 35 without passing through, and permeates the portion backfilled with the removal material 4.

  Further, for example, as shown in FIGS. 21 and 22, a guide member 43 including three guide plates 40, 41 and 42 arranged with a gap in parallel with each other may be used. In such a guide member 43, three guide plates 40, 41, 42 are arranged in parallel with each other by a support portion 44 with a gap therebetween, and between the center guide plate 41 and one guide plate 40 and in the center guide. A gap is provided between the plate 41 and the other guide plate 42.

  By inserting the guide member 43 into the emptied casing 10, as shown in FIG. 23, the inside of the casing 10 has an area 45 between the central guide plate 41 and one guide plate 40, and A region 46 between the central guide plate 41 and the other guide plate 42 and a region 47 located outside the one guide plate 40 (region 47 surrounded by the outer surface of one guide plate 40 and the inner surface of the casing 10). ) And a region 48 located outside the other guide plate 42 (region 48 surrounded by the outer surface of the other guide plate 42 and the inner surface of the casing 10). As described above, also when the guide member 43 is inserted into the casing 10, the guide plates 40, 41, 42 are installed so as to be parallel to the extension direction of the permeation reaction wall 55 described later.

  Then, the purification material 50 is put into the region 45 between the central guide plate 41 and the one guide plate 40 to be backfilled, and similarly, the region 46 between the central guide plate 41 and the other guide plate 42 is filled. The purification material 51 is introduced into the backfill. In this case, it is assumed that the purification material 50 put into the region 45 and the purification material 51 put into the region 46 are of different types.

  Further, a region 47 located outside the one guide plate 40 (region 47 surrounded by the outer surface of one guide plate 40 and the inner surface of the casing 10) and a region 48 located outside the other guide plate 42 (the other one). An area 48) surrounded by the outer surface of the guide plate 42 and the inner surface of the casing 10 is filled with a water-permeable backfill material 52 instead of a purifying material. In this case, crushed stone or the like is used for the backfill material 52. Further, the soil 3 excavated on site may be used as the backfill material 52. The backfilling of the purification materials 50 and 51 and the backfilling material 52 is performed using, for example, a backhoe.

  Thereafter, the casing 10 and the guide member 43 are extracted upward from the ground 2 by being lifted by the crane 12. By performing this process as many times as necessary, as shown in FIG. 24, it is possible to construct a permeation reaction wall 55 in which the purification materials 50 and 51 are arranged in two layers.

  The permeation reaction wall 55 created in this manner has two types of purification materials 50 and 51 arranged in two layers, so that permeation reaction walls having different properties can be constructed simultaneously. For example, it becomes possible to purify the groundwater 7 contaminated with two or more kinds of chemical substances using two kinds of purification materials 50 and 51. Alternatively, another chemical substance generated by decomposing the chemical substance with the purifying material 50 that comes into contact with the groundwater 7 first can be decomposed or removed by adsorption with the next purifying material 51.

  9, 10 and FIGS. 17 and 18, a guide member 15 (30) including two guide plates 16, 16 (31, 31) will be described. In FIGS. However, the number of guide plates is arbitrary, and may be one or four or more, for example. In any case, according to the present invention, since the purification material is backfilled after the inside of the casing is divided by the guide plate, the shape of the backfilling of the purification material can be shaped by the arrangement of the guide plate. The side shape of the permeation reaction wall made of can be changed as desired. Further, a permeation reaction wall having a higher degree of freedom can be formed by changing the size (thickness) of the space into which the purification material is introduced by the arrangement of the guide plate.

  INDUSTRIAL APPLICABILITY The present invention is useful, for example, for constructing a permeation reaction wall for the purpose of preventing contamination diffusion or purifying groundwater with respect to groundwater contaminated by chemical substances generated by factory operations.

DESCRIPTION OF SYMBOLS 1, 10 Casing 2 Ground 3 Soil 4, 50, 51 Purification material 5 Permeation reaction wall part 6 Permeation reaction wall 7 Ground water 11 Excavator 12 Crane 15, 30, 43 Guide members 16, 31, 40, 41, 42 Guide plate 17 , 32, 44 Support portion 20 Regions 20a, 20b located between the two guide plates Region portion 21 Regions 22, 35, 52 located outside the guide plate Backfill material 25 Permeation reaction wall portion 26 Planes 27, 36, 55 Permeation reaction wall 33 Auxiliary plate 45 Region 46 between the center guide plate and one guide plate Region 47 between the center guide plate and the other guide plate Region 48 located outside one guide plate The other side Area located outside the guide plate

Claims (5)

By inserting a cylindrical casing into the ground, removing the soil in the casing, and then backfilling the purification material in the casing, by repeatedly performing a step of providing a columnar permeation reaction wall portion in the ground, a plurality of A permeation reaction wall part is constructed adjacent to the ground to construct a permeation reaction wall,
When the purification material is backfilled in the casing, the inside of the casing is divided into a plurality of regions using one or more guide plates, and the purification material is backfilled in a region divided by the guide plates, Permeation reaction wall construction method.   The permeation reaction wall construction method according to claim 1, wherein the guide plate is installed in the casing in parallel with the extending direction of the permeation reaction wall.   The permeation reaction wall according to claim 1 or 2, wherein two guide plates are installed parallel to each other with a gap in the casing, and the purifying material is backfilled in a region between the two guide plates. Construction method.   In the casing, three or more guide plates are installed parallel to each other with a gap, and different purification materials are embedded in the region between any two guide plates and the region between any two other guide plates. The permeation reaction wall construction method according to claim 1, wherein the permeation reaction wall construction method is returned. A guide member used in a step of providing a columnar permeation reaction wall portion in the ground by inserting a cylindrical casing into the ground, removing soil in the casing, and then backfilling the purification material in the casing. ,
A guide member, comprising: a plurality of guide plates that divide the inside of the casing; and a support portion that supports the plurality of guide plates in parallel with each other with a gap therebetween.

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