JP2011099285A - Connecting member and method for improving soil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting member which connects a drain device exposed on a ground to a collecting pipe with the airtightness secured. <P>SOLUTION: This connecting member 1 connects the drain device 3 and the collecting pipe 4 together. The drain device 3 includes a permeable member 12 which is formed of a permeable material and driven into soft ground, and an impermeable member 13 which is made of an impermeable material, which has a hollow portion allowing the insertion of the permeable member 12 and which is placed into the ground to be exposed by a predetermined length from the ground surface of the soft ground. The connecting member 1 has a body 17 in which an insertion hole 15 for inserting the permeable member 12 of the drain device 3 is formed at one end, in which a water leading portion 16 for leading groundwater into the collecting pipe 4 is formed at the other end, and in which the leading end of the impermeable member 13 is attached in a covering manner to an outer surface toward the side of the other end from the side of the one end. In the body 17, a tapered portion 20, the diameter of which becomes larger than the opening diameter of the impermeable member 13, is formed toward the side of the other end from the side of the one end. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a connection member for connecting a drain device used to improve the soft ground by discharging moisture contained in the ground and a water collecting pipe for collecting groundwater pumped up using the drain device, and the connection. The present invention relates to a ground improvement method using members.

  Conventionally, an atmospheric pressure construction method is known as one of ground improvement methods for improving soft ground to hard ground by discharging moisture and air in the soft ground. In this atmospheric pressure construction method, a vertical drain material is placed in soft ground, the ground surface is covered with a sealing sheet, and a load is applied by a pressure difference (atmospheric pressure difference) by reducing the pressure inside the sheet. And it is the construction method which promotes consolidation of the ground by draining the water in the ground through the vertical drain material.

  This atmospheric pressure method needs to cover the ground surface with a sealing sheet while ensuring airtightness, and there are problems in work efficiency and economy.

  Therefore, various soft ground improvement methods using vacuum consolidation without using a sealing sheet have been proposed (see, for example, Patent Document 1). In the soft ground improvement method by vacuum consolidation shown in Patent Document 1, instead of using a sealing sheet, the inner end has water permeability by a certain length from the end portion, and the air passage from the peripheral surface is blocked. It describes about using the drain material provided with the air permeable part.

  By the way, the construction method as shown to patent document 1 leaves the drain material which has an air-impermeable part in the ground after ground improvement. In particular, the air-impermeable portion that is placed on the surface layer in the relatively shallow ground and left behind has been an obstacle due to the necessity of disposal in excavation work associated with the subsequent land development. Moreover, such a drain material is used as a disposable type, and there is a concern about the environmental load.

  Therefore, in recent years, as an improvement method for soft ground, the impermeable portion of the drain material is buried at a predetermined depth from the ground, and the upper end of the impermeable portion is projected to the ground surface, so that the airtight connection member and the ground surface are embedded. There has been proposed a method of connecting the upper end of the air-impermeable portion that is exposed to the surface. In such a construction method, the connecting member is also connected to the water collecting pipe, and the inside of the water collecting pipe is decompressed by a vacuum pump to promote drainage without using a sealing sheet.

  As described above, the drain member is connected to the water collecting pipe through the connection member attached to the upper end. The connecting member has an opening having a size that allows the upper end of the drain material provided with an air-impermeable portion at one end to be inserted. When the upper end of the drain material is inserted, the opening is sealed with tape, an adhesive, or the like. By stopping, it is connected to the drain material (see FIG. 15).

  In addition, the connection member is provided with a water guide part that guides the moisture in the ground collected by the drain material to the water collection pipe at the other end, and the water conduction part is connected to the water collection pipe installed at the construction site, so that the drain The underground water collected by the material is introduced to the water collecting pipe.

JP 2001-226951 A

  In this way, the connection between the upper end of the drain material facing the ground surface and the connection member is performed by bonding the air-impermeable portion of the drain material and the opening of the connection member with an adhesive, and then attaching the tape to the air-impermeable portion. Although it was carried out by a method such as winding around the boundary with the opening, there was a case where the connection portion was not sufficiently sealed. And since the connection location of the drain material and the connection member is exposed to the ground surface, if the connection location is not sealed, even when the vacuum pump is operated, the pressure cannot be reduced to a predetermined pressure, and the load may be insufficient. .

  Therefore, an object of the present invention is to provide a connection member that can be connected to a drain material in an airtight state, and a soft ground improvement method using the connection member.

  In order to solve the above-described problems, a connection member according to the present invention is formed so as to have a hollow portion with a water-permeable material, and is formed with a water-permeable member that is placed at a predetermined depth in a soft ground. A drain device comprising a material that has a hollow portion through which the water-permeable member is inserted, and a water-impermeable member that is placed on the soft ground leaving a predetermined length from the ground surface of the soft ground; In the connecting member that connects the water collecting pipe that collects the groundwater pumped up by the drain device, an insertion hole into which the tip of the water-permeable member of the drain device is inserted is formed at one end, and the insertion hole is continuous with the other end. And a water guide part that guides groundwater to the water collecting pipe, and has a main body on which an end of the water-impermeable member is attached to an outer surface from the one end side toward the other end side. To above Toward the end side, in which the tapered portion to continue to diameter larger than the opening diameter of the impermeable member is formed.

  Further, the soft ground improving method according to the present invention includes a water permeable member formed to have a hollow portion with a water permeable material, and placed at a predetermined depth in the soft ground, and the water permeable material using the water permeable material. A drain device comprising a hollow portion through which the member is inserted and having a predetermined length from the ground surface of the soft ground, and a water-impermeable member that is placed on the soft ground; A step of projecting the front end of the drainage device into the soft ground, inserting the water-permeable member of the drain device into the insertion hole of the connection member, and attaching the water-impermeable member to the connection member A step of connecting the connecting member to the water collecting pipe and a step of reducing the pressure inside the water collecting pipe, and in the step of attaching the water-impermeable member to the connecting member, Formed on the outer surface of the connecting member Re those going over the tapered portion continue to diameter larger than the opening diameter of the impermeable member.

  According to the present invention, the tapered portion formed from one end side to the other end side of the main body expands more than the opening diameter of the water-impermeable member. It can be tightly attached to the body. Therefore, since this invention can connect a drain apparatus and a connection member in an airtight state, the state decompressed by the vacuum pump can be maintained and the water | moisture content in a soft ground can be drained efficiently.

It is sectional drawing explaining the soft ground improvement method concerning this invention. It is a top view explaining the soft ground improvement method concerning this invention. It is a perspective view which shows a drain apparatus. It is a perspective view which shows the drain apparatus in which an air-impermeable part is formed. It is a perspective view which shows the water collection pipe | tube to which a drain apparatus is connected. It is a figure which shows a connection member, (a) is a top view, (b) is a front view. It is a figure which shows the connection member connected with the drain apparatus. It is a perspective view which shows the connection member which made the main surface bulge. It is a perspective view which shows the connection member which apply | coated the adhesive agent. It is a top view which shows the connection member connected with the hose with the stapler. It is a top view which shows the connection member connected with the hose with the adhesive tape. It is a figure which shows the state in which the several drain apparatus is connected with one through the connection member. It is a figure for demonstrating an Example and a comparative example. It is a perspective view which shows the comparative example which connected the front-end | tip of the drain apparatus to the cylindrical socket. It is a top view which shows the reference example which connected the drain apparatus to the flat plate socket by which the insertion hole of substantially the same shape as the drain apparatus was formed in the end surface. It is a figure which shows the other connection member concerning this invention, (a) is sectional drawing, (b) is a bottom view. It is a side view which decomposes | disassembles and shows the structure of the other connection member concerning this invention. It is a top view which shows the state which connected the drain apparatus to the joint piece. It is a top view which shows the state which connected the joint piece and the joint cover to which the drain apparatus was connected. It is a top view which shows the state which connects the joint cover by which the joint piece was fitted, and a joint body.

  Hereinafter, a connection member to which the present invention is applied and a soft ground improvement method will be described in detail with reference to the drawings. As shown in FIG. 1, the soft ground improvement method to which the present invention is applied promotes and improves the consolidation settlement by sucking up moisture contained in the ground of the soft ground 2, and is applied to the soft ground. A drain device 3 installed, a water collecting pipe 4 collecting water in the ground collected from the drain device 3, a connecting member 1 connecting the drain device 3 and the water collecting pipe 4, and a water collecting pipe 4 And a vacuum pump 8 serving as decompression means for decompressing the inside of the drain device 3.

  In this soft ground improvement method, as shown in FIG. 2, a drain device 3 is placed at a predetermined interval in the soft ground 2, and the tip of the drain device 3 facing the ground surface is connected to the connection member 1. In addition, the connecting member 1 and the water collecting pipe 4 are connected. The connecting member 1 is provided with a water guiding portion 16, and the water guiding portion 16 is connected to the water collecting pipe 4. Each water collection pipe 4 is connected to a large-diameter drain pipe 6, and the inside of the water collection pipe 4 and the drain device 3 is decompressed by a vacuum pump 8 connected to the drain pipe 6. As a result, moisture in the ground is sucked up through the drain device 3 and discharged through the water collecting pipe 4 and the drain pipe 6.

  As shown in FIG. 3, the drain device 3 includes a drain material 12 serving as a water permeable member through which moisture in the soft ground 2 flows, and a hose 13 provided at an end of the drain material 12 and serving as an impermeable member. Is provided. The drain material 12 includes a core material 10 that serves as a water passage for moisture in the soft ground 2 and a filter 11 that is provided around the core material 10 and transmits moisture in the soft ground 2. The core material 10 is provided with a plurality of partition walls extending in the longitudinal direction on both surfaces of the long body, whereby a plurality of grooves 10a serving as moisture passages in the soft ground 2 are formed in the longitudinal direction. . This core material 10 has a certain degree of flexibility in consideration of convenience of transportation and the like, and a material having a shape retaining property for securing a sufficient water passage even after being placed on the soft ground 2, For example, it is formed using polyolefin or other resin materials. Moreover, even if the core material 10 is formed of, for example, a biodegradable resin material, it can reduce the environmental load even when left in the soft ground 2.

  The filter 11 covering the periphery of the core material 10 is formed of a material having water permeability, for example, a nonwoven fabric made of polyester. The filter 11 may be formed in a long shape, and may be wound around the core material 10 to cover the periphery of the core material 10 by being bonded by heat welding or the like.

  Further, the drain device 3 is formed with an air-impermeable portion by covering the tip of the drain material 12 from the ground surface to several tens to several hundreds of centimeters with a hose 13 formed of an impermeable material. ing. As shown in FIG. 4, the hose 13 is formed with an annular body having a size capable of covering the drain device 3 using a water-impermeable material such as polypropylene or vinyl chloride, and is inserted through the distal end portion of the drain material 12. Let In addition, the hose 13 and the front-end | tip part of the drain material 12 are fixed by well-known methods, such as a stapler, a tape, an adhesive agent, and welding.

  In this soft ground improvement method, the ground from the ground surface of the drain device 3 to several tens to several hundreds of centimeters is covered with a water-impermeable material so that the soft ground 2 is not covered with a sheet that seals the ground by vacuum consolidation. Improvement work can be performed.

  The drain device 3 is manufactured in advance in a manufacturing factory by covering the core material 10 with the filter 11 and the hose 13 at predetermined intervals, and the connecting member 1 is connected at every predetermined interval. And then wound into a roll. The connection between the drain device 3 and the connection member 1 will be described in detail later. Then, it is carried into the construction site in a roll state, and is placed on the soft ground 2 at a predetermined interval by the same procedure as that for normal vertical drain placement.

  At this time, in the drain device 3, the front end side of the air-impermeable portion to which the connecting member 1 is connected protrudes from the ground surface. Then, the connecting member 1 is connected to the water collecting pipe 4 at the water guiding portion 16. Thereby, the drain device 3 is connected to the water collecting pipe 4 through the connecting member 1, and the inside of the drainage device 3 is decompressed by the vacuum pump 8, thereby sucking moisture in the soft ground 2 and flowing it to the water collecting pipe 4. it can.

  Water collecting pipes 4 that collect water discharged from the drain device 3 are installed on the soft ground 2 at predetermined intervals. The water collecting pipe 4 is attached to the outer peripheral portion at the tip of a water guiding portion 16 of the connecting member 1 described later. A single water collecting pipe 4 is connected to a plurality of drain devices 3 via a connecting member 1, and water in the soft ground 2 discharged from each drain device 3 is collected. Further, the water collected by the plurality of water collecting pipes 4 is drained out of the soft ground 2 through the large-diameter drain pipe 6.

  When the water collecting pipe 4 is carried into the soft ground 2 which is an enforcement site and is installed at a predetermined position, the connecting member 1 connected to the drain device 3 is attached. As shown in FIG. 5, the connection member 1 is attached to the attachment portion 5 formed on the outer peripheral portion of the water collecting pipe 4 and provided with the attachment hole 5a, and airtightness is secured by an adhesive or the like. While doing.

  Moreover, the inside of the water collecting pipe 4 is decompressed by decompression means such as a vacuum pump 8 connected to the drain pipe 6, thereby draining the water in the ground of the soft ground 2 into the drain device 3.

  Next, the connecting member 1 that connects the drain device 3 and the water collecting pipe 4 will be described. As shown in FIG. 6, the connection member 1 has an insertion hole 15 into which the tip of the drain material 12 of the drain device 3 is inserted at one end, and is connected to the water collecting pipe 4 at the other end to pass through the drain device 3. A main body 17 having a water guide portion 16 for guiding the discharged water to the water collecting pipe 4. As shown in FIG. 7, the connecting member 1 is connected to the drain device 3 by inserting the drain material 12 into the insertion hole 15 of the main body 17 and attaching the hose 13 to the outer surface of the main body 17. Further, the connecting member 1 is connected to the water collecting pipe 4 by attaching the water guiding part 16 to the attaching part 5 of the water collecting pipe 4.

  The main body 17 is molded using a polyolefin resin or the like. Moreover, the main body 17 has a substantially flat shape, and is formed in a hollow shape in which the insertion hole 15 formed on one end surface and the water guide portion 16 formed on the other end surface are continuous.

  The insertion hole 15 is opened in a substantially rectangular shape and has substantially the same width and thickness as the drain material 12. The water guide portion 16 has a cylindrical shape that can be inserted into the mounting hole 5 a of the mounting portion 5 formed on the outer peripheral portion of the water collecting pipe 4.

  In addition, the main body 17 to which the hose 13 that becomes the water-impermeable member of the drain device 3 is attached has a tapered portion that is larger in diameter than the opening diameter of the hose 13 from one end to the other end in the insertion direction of the hose 13. 20 is formed. The tapered portion 20 is formed on both side surfaces 17 a and 17 b in the width direction of the insertion hole 15 of the main body 17.

  The main body 17 is gradually enlarged from one end to the other end between the side surfaces 17a and 17b by forming the tapered portion 20. The main body 17 has an outer diameter at one end smaller than the opening diameter of the hose 13, but the outer diameter increases toward the other end and becomes larger than the opening diameter of the hose 13.

  Therefore, when the connecting member 1 covers the outer surface of the main body 17 from the one end side, the hose 13 is tensioned by the tapered portion 20. Since the hose 13 has some elasticity, the hose 13 is in close contact with the main body 17 by being covered with the main body 17 until it is tensioned along the tapered portion 20.

  Thereby, the connection member 1 can seal the connection part with the front-end | tip of the drain apparatus 3 which faced the ground surface, and can prevent the inflow of the air from the said connection part also at the time of pressure reduction by the vacuum pump 8. it can. Therefore, in the construction method using the connection member 1, the predetermined atmospheric pressure reduced by the vacuum pump 8 can be maintained, and drainage can be efficiently performed from the soft ground.

  Further, as shown in FIG. 8, the connecting member 1 may be formed such that both main surfaces 17c and 17d adjacent to both side surfaces 17a and 17b of the main body 17 formed with the tapered portion 20 gradually bulge. . That is, the main body 17 has both main surfaces 17 c and 17 d formed in the insertion direction of the hose 13 along the longitudinal direction of the insertion hole 15 facing one end surface. Both the main surfaces 17c and 17d may be formed so as to bulge in the short direction of the insertion hole 15 with the center position in the longitudinal direction of the insertion hole 15 being the thickest part in addition to being formed flat.

  By swelling both the main surfaces 17c and 17d, the connecting member 1 can be tensioned over the entire circumference of the opening of the hose 13 together with the tapered portion 20 when the hose 13 is covered. It can be brought into close contact with the outer surface of the main body 17. Thereby, the connection member 1 can seal the connection location with the front-end | tip of the drain apparatus 3 which faced the ground surface more firmly, and can prevent the inflow of the air from the said connection location.

  Moreover, as shown in FIG. 9, the connection member 1 may apply | coat the adhesive agent 23 previously to the outer surface of the main body 17 to which the hose 13 is adhered. Thereby, the connecting member 1 allows the hose 13 to be more closely attached to the outer surface of the main body 17 to prevent the inflow of air and improve the airtightness, and at the time of transporting the drain device 3 or placing it on the soft ground 2. The device 3 can be prevented from coming off.

  As shown in FIG. 10, the connecting member 1 may connect the main body 17 and the drain material 12 by the stapler 24 after the drain material 12 is inserted into the main body 17. Thereby, the connection member 1 can prevent the connection member 1 and the drain material 12 from being separated when the drain device 3 is placed.

  Further, as shown in FIG. 11, the connecting member 1 may seal the boundary between the main body 17 and the hose 13 with the adhesive tape 25 after the hose 13 is attached to the main body 17. Also by this, the connection member 1 can make the hose 13 more closely contact the outer surface of the main body 17 and can prevent the hose 13 from coming off.

  The connecting member 1 may adhere the main body 17, the drain material 12, and the hose 13 by appropriately combining the application of the adhesive 23, the connection with the stapler 24, and the sealing with the adhesive tape 25. By using all of the adhesive 23, the stapler 24 and the adhesive tape 25, the connecting member 1 can perform the connection with the drain device 3 while ensuring the airtightness by bringing the hose 13 into close contact with the outer surface of the main body 17. In addition, it is possible to prevent the drain device 3 from coming off when the drain device 3 is placed.

  Next, the soft ground improvement work using the connecting member 1 will be described. First, the drain device 3 is connected to the connection member 1. Specifically, in the connection member 1, the drain material 12 is inserted into the insertion hole 15, and the hose 13 is attached to the outer surface of the main body 17. At this time, since the connecting member 1 has tapered portions 20 on both side surfaces 17a and 17b, the hose 13 is tensioned by the tapered portion 20 when the hose 13 is put on the outer surface of the main body 17 from one end side. . Therefore, the connecting member 1 is in close contact with the main body 17 by covering the main body 17 until the hose 13 is tensioned along the tapered portion 20. Note that the drain device 3 is cut in advance to a length corresponding to the depth of placement on the soft ground 2.

  The connecting member 1 is connected by a stapler 24 after the drain material 12 is inserted into the main body 17, and then the adhesive 23 is applied to the outer surface of the main body 17, and the adhesive tape 25 is applied across the boundary with the hose 13. By winding around the outer surface 17, it is possible to prevent the drain device 3 from being pulled out and to ensure the airtightness of the connection portion with the drain device 3.

  In the drain device 3, after the connection member 1 is connected to the tip provided with the hose 13 serving as the air-impermeable portion, the connection member 1 is also connected to the rear end portion where the hose 13 is not provided. At this time, the drain device 3 is configured such that the drain material 12 at the rear end is inserted into the insertion hole 15 of the connection member 1 and the adhesive tape 25 is wound around the boundary between the drain material 12 and the connection member 1. The material 12 is prevented from coming off.

  Next, the water guide portion 16 of the connection member 1 attached to the rear end of the drain device 3 and the water guide portion 16 of the connection member 1 connected to the front end of the other drain device 3 are connected. The water guiding portions 16 of the connecting member 1 are connected to each other via a bendable connector (not shown). Then, as shown in FIG. 12, the drain device 3 has a connecting member 1 connected to the tip of the drain device 3 connected to a connecting member 1 connected to the rear end of the other drain device 3, and the other drain device 3 The connecting member 1 connected to the front end is connected to the connecting member 1 connected to the rear end of another drain device 3. Thus, the several drain apparatus 3 provided with the length according to the placement depth to soft ground is connected with one, wound in roll shape, and is conveyed to the placement site.

  At the placement site, the drain device 3 is separated from the connecting member 1 connected to the front end and the other connecting member 1 connected via the coupling tool, and before the connecting member 1 connected to the rear end. The drain member 12 is cut, and the connecting member 1 connected to the rear end is cut off. Then, the drain device 3 is vertically driven at a predetermined interval on the soft ground 2 by a driving machine. As described above, the drain device 3 has the connection member 1 attached to the tip in advance, and is connected to one as in the conventional case and wound in a roll shape. Therefore, the conventional construction method can be applied as it is. In addition, the placement ability is not reduced.

  After the placement, the placement holes formed in the soft ground 2 are backfilled as necessary. At this time, the drain device 3 is provided with a hose 13 where the tip side which becomes an air-impermeable portion is buried in a place extending from the ground surface to a depth of several tens to several hundreds cm below and the tip to which the connecting member 1 is connected. The part protrudes to the ground surface and can be attached to the attachment part 5 of the water collecting pipe 4.

  Thereafter, the water guiding portion 16 of the connecting member 1 is inserted into the mounting hole 5a opened at the tip of the mounting portion 5 of the water collecting pipe 4 and connected by an adhesive. Furthermore, the connection member 1 may wind the insertion location to the attachment part 5 of the water guide part 16 with an adhesive tape. After all the connecting members 1 connected to the drain apparatus 3 placed are connected to the water collecting pipe 4, the vacuum pump 8 connected to the drain pipes 6 connected to the plurality of water collecting pipes 4 is operated, The pressure is reduced to Thereby, the inside of the water collecting pipe 4 is depressurized, and the water in the ground of the soft ground 2 is drained into the drain device 3.

  After draining the water in the soft ground 2 over a predetermined period and finishing the ground improvement, the tip of the drain device 3 facing the ground surface is cut, whereby the connecting member 1 is recovered and washed. It can be reused later.

  Next, an example in which the connecting member 1 is connected to the drain device 3 and a comparative example in which another connecting member is connected to the drain device 3 will be described. In this example and comparative example, the drain device 3 that has been imperviously processed by covering the drain material 12 with the hose 13 is connected to the connection member 1 (example) or the cylindrical socket 50 (comparative example). The connecting member 1 and the cylindrical socket 50 were connected to a vacuum pump. As shown in FIG. 13, the connecting member 1 and the cylindrical socket 50 and the vacuum pump P are connected via a cell 53 to which a pressure gauge 52 is connected. Valves are provided between the cell 53 and the vacuum pump P, and between the cell 53 and the connection member 1 and the cylindrical socket 50. After operating the vacuum pump, the connecting member 1 and the cylindrical socket 50 are immersed in water to check whether the drain material 12, the connecting member 1 or the cylindrical socket 50 has inflow of water, and after being immersed in water, 5 The pressure change after the lapse of minutes was examined. Since the pressure gauge measures negative pressure, if there is an inflow of water into the drain member 12, the connecting member 1 or the cylindrical socket 50, the value of the pressure gauge is, for example, −0.09 Mpa → −0.08 Mpa. growing.

  In the example, the drain material 12 was inserted into the insertion hole 15 of the connection member 1, and the hose 13 was attached to the outer periphery of the main body 17 of the connection member 1. At this time, the connection between the main body of the connection member 1 and the hose 13 is performed by applying the adhesive 23 to the outer surface of the main body 17 and winding the boundary between the main body 17 and the hose 13 with the adhesive tape 25 after the hose 13 is attached. Turned (see FIG. 7).

  In the comparative example, as shown in FIG. 14, the tip of the drain device 3 that has been imperviously processed by covering the drain material 12 with the hose 13 was connected to the cylindrical socket 50. Specifically, in the drain device 3, the drain material 12 is inserted into the hollow interior of the cylindrical socket 50, and the hose 13 is attached to the outer peripheral surface of the cylindrical socket 50. Since the outer peripheral surface is not inclined in the height direction, the cylindrical socket 50 is a connecting member in which a tapered portion is not formed from one end to the other end. In this comparative example, the cylindrical socket 50 and the hose 13 are connected by applying the adhesive 23 to the outer peripheral surface of the cylindrical socket 50 and attaching the hose 13 to the cylindrical socket 50 and the hose 13 with the adhesive tape 25. And the same conditions as Example 1 except for the shape of the connecting member.

  As a reference example, as shown in FIG. 15, the drain device 3 that has been imperviously covered with the hose 13 over the entire drain material 12 has an insertion hole that has substantially the same shape as the drain device 3 on the end surface 51 a. It connected to the formed flat socket 51, and it evacuated in the state which submerged this flat socket 51 in water, and the presence or absence of inflow of water was confirmed. In the flat socket 51, an insertion hole having the same diameter as that of the drain device 3 is formed on the end surface 51a, and a hollow cylindrical portion continuous with the insertion hole is formed on the other end 51b side. In this reference example, the drain material 3 and the hose 13 of the drain device 3 are all inserted into the insertion holes of the flat plate socket 51, and the boundary between the hose 13 and the insertion holes is wound with the adhesive tape 25, thereby the drain device 3 and the flat plate. The socket 51 was connected. In this reference example, the pressure change after depressurization was not measured.

  As shown in Table 1, in this example, no inflow of water into the connection member 1 or the drain material 12 was observed. In this example, the pressure did not change (0.097 Mpa) even after 5 minutes had elapsed after the vacuum pump was operated, and no pressure change was observed.

  On the other hand, in the comparative example, inflow of water into the cylindrical socket 50 and the drain material 12 was observed. In the comparative example, the pressure (negative pressure) changed from 0.085 Mpa to 0.080 Mpa when 5 minutes passed after the vacuum pump was operated. This indicates that the negative pressure has decreased, and it can be seen that there is a problem with the tightness of the connection with the drain device 3.

  That is, in the present embodiment using the connecting member 1, it is understood that the inflow of water is prevented even under reduced pressure, and the drain device 3 and the connecting member 1 are closely connected. On the other hand, in the comparative example using the cylindrical socket 50 having no taper portion, it can be seen that water flows in under reduced pressure, and the drain device 3 and the cylindrical socket 50 are not tightly connected. Therefore, it can be seen that by providing the tapered portion 20, the connecting member 1 can be tightly connected to the drain device 3 when the hose 13 is tensioned by the tapered portion 20.

  In the reference example, when the inside of the flat socket 51 is evacuated, the drain device 3 is contracted inward, and the hose 13 is separated from the adhesive tape 25, whereby a gap is formed between the hose 13 and the adhesive tape 25. Water entered from this gap. Thereby, it can be seen that the drain device 3 preferably has a configuration in which the drain member 12 is inserted into the connecting member and the hose 13 is attached to the outer surface of the connecting member in order to achieve a close connection.

  Next, another connecting member to which the present invention is applied will be described. The connecting member 30 is of a type that is attached to the distal end portion of the drain device 3 that protrudes to the ground surface at the site after the drain device 3 is driven into the soft ground 2. As shown in FIGS. 16 and 17, the connecting member 30 includes a joint piece 31 into which the drain material 12 of the drain device 3 is inserted and a hose 13 is attached, a joint cover 32 and a joint that sandwich the joint piece 31. It consists of a body 33. The connecting member 30 is airtight with the drain device 3 by mounting the drain device 3 on the joint piece 31 and then covering the joint piece 31 with the joint cover 32 from one end side and further covering the joint body 33 from the other end side. It is connected while maintaining sex.

  The joint piece 31 is molded using nylon (with glass fiber) or the like, and forms a substantially rectangular plate-like body that can be attached to the drain device 3 as shown in FIG. The joint piece 31 has an insertion hole 35 into which the drain material 12 is inserted at one end side. The insertion hole 35 is opened in a substantially rectangular shape on one end surface of the joint piece 31 and faces the other end surface. That is, the joint piece 31 has a hollow shape in which the insertion hole 35 penetrates from one end surface to the other end surface. In addition, the insertion hole 35 has a width in the longitudinal direction and a thickness in the short direction substantially the same as the width and thickness of the drain material 12.

  Moreover, the hose 13 used as the water-impermeable member of the drain device 3 is attached to the outer surface of the joint piece 31. The joint piece 31 is formed with a taper portion 36 whose diameter is larger than the opening diameter of the hose 13 from one end to the other end in the insertion direction of the hose 13. The tapered portion 36 is formed on both side surfaces 31 a and 31 b of the joint piece 31 provided in the longitudinal direction of the insertion hole 35.

  Since the joint piece 31 is formed with the tapered portion 36, the side surfaces 31a and 31b are gradually separated from one end to the other end. The joint piece 31 has an outer diameter at one end smaller than the opening diameter of the hose 13, but the outer diameter increases toward the other end and becomes larger than the opening diameter of the hose 13.

  Therefore, when the connecting member 30 covers the outer surface of the joint piece 31 from the one end side, the hose 13 is tensioned by the tapered portion 36. Since the hose 13 has some elasticity, the hose 13 is in close contact with the joint piece 31 by being put on the joint piece 31 until it is tensioned along the tapered portion 36.

  Further, the joint piece 31 has a flange portion 34 formed on the other end surface. The flange portion 34 is locked to the first locking step portion 39 a of the fitting hole 37 formed in the joint cover 32 and sandwiches the packing 46 with the joint body 33.

  The joint cover 32 and the joint body 33 that sandwich the joint piece 31 are molded using nylon (with glass fiber) or the like. The joint cover 32 and the joint body 33 seal the joint piece 31 inside by being butt-joined.

  The joint cover 32 is formed with a fitting hole 37 into which the joint piece 31 is fitted, and the fitting hole 37 has a hollow shape penetrating from one end surface to the other end surface. The fitting hole 37 has substantially the same shape as that of the joint piece 31, and the hose 13 attached to the joint piece 31 is clamped together with the outer surface of the joint piece 31 by the fitting of the joint piece 31. The hose 13 is adhered to the joint piece 31 in an airtight manner.

  In addition, the fitting hole 37 includes a first locking step portion 39 a that the flange portion 34 of the joint piece 31 locks, a contact surface portion 43 of the joint body 33, and a packing 46 that locks the other end surface side. Two locking step portions 39b are formed.

  Further, the joint cover 32 is formed with a flange portion 40 coupled to the joint body 33 on the other end surface on which the locking step portion 39 is formed. The flange portion 40 is formed with a screw hole 41 through which a connection screw 47 connected to the joint body 33 is inserted.

  The joint body 33 that airtightly holds the joint piece 31 by being connected to the joint cover 32 is formed with an abutting surface portion 43 that abuts the flange portion 34 of the joint piece 31 at one end, and the attachment of the water collecting pipe 4 at the other end. A connection hole 44 into which the part 5 is inserted is formed. The joint body 33 has a hollow shape in which the connection hole 44 penetrates from one end surface where the contact surface portion 43 is formed to the other end surface. The joint body 33 faces the joint piece 31 so that the connection hole 44 is continuous with the insertion hole 35 facing the other end surface of the joint piece 31, and the groundwater pumped up by the drain material 12 is drained to the water collecting pipe 4. To do.

  Further, the joint body 33 is formed with a screw hole 45 that is continuous with the screw hole 41 formed in the flange portion 40 at the outer edge facing the flange portion 40 of the joint cover 32.

  In such a connection member 30, the tip exposed to the ground surface of the drain device 3 placed in the ground of the soft ground 2 is inserted into the fitting hole 37 of the joint cover 32. At this time, the joint cover 32 is inserted with the other end on which the flange portion 40 is formed facing the distal end side of the drain device 3.

  Next, as shown in FIG. 18, the tip of the drain device 3 is attached to the joint piece 31. Specifically, in the joint piece 31, the drain material 12 is inserted into the insertion hole 35 and the hose 13 is attached to the outer surface. At this time, since the joint piece 31 has tapered portions 36 formed on both side surfaces 31a and 31b, the hose 13 is tensioned by the tapered portion 36 when the hose 13 is put on the outer surface from one end side. Accordingly, the joint piece 31 is brought into close contact with the hose 13 by being covered until the hose 13 is tensioned along the tapered portion 36.

  Next, as shown in FIG. 19, the joint piece 31 is fitted into the fitting hole 37 of the joint cover 32 that has been previously inserted into the drain device 3. When the joint cover 32 is inserted until the flange portion 34 of the joint piece 31 is locked by the first locking step portion 39 a in the fitting hole 37, the inner wall of the fitting hole 37 and the joint piece 31 The hose 13 is clamped by the tapered portion 36. The joint cover 32 may be further improved in airtightness by applying a sealing agent to a groove (not shown) provided in advance in the locking step 39a before the joint piece 31 is fitted. Good.

  Next, as shown in FIG. 20, the joint body 33 is connected to the joint cover 32 via the packing 46. As shown in FIG. 16A, the joint body 33 is inserted until the contact surface portion 43 is locked to the second locking step portion 39 b formed in the fitting hole 37 of the joint cover 32. The screw hole 45 is in contact with the flange portion 40 of the joint cover 32, and the screw hole 45 is continuous with the screw hole 41 formed in the flange portion 40. Then, a connecting screw 47 is screwed from the screw hole 45 side to connect the joint cover 32 and the joint body 33. Accordingly, the packing 46 is sandwiched between the contact surface portion 43 of the joint body 33, the second locking step portion 39 b of the fitting hole 37, and the flange portion 34 of the joint piece 31.

  By connecting the joint cover 32 and the joint body 33, the connection member 30 securely holds the hose 13 between the tapered portion 36 of the joint piece 31 and the inner wall of the fitting hole 37 of the joint cover 32, and The hose 13 can be brought into close contact with the outer surface of the joint piece 31 to prevent the hose 13 from coming off. Further, the connecting member 30 causes the joint piece 31 and the joint body 33 to come into close contact with each other via the packing 46, and if necessary, a sealing agent is applied to the groove portion of the locking step portion 39a of the joint cover 32. Thus, air can be prevented from flowing into the insertion hole 35 from the other end surface of the joint piece 31.

  Thereby, the connection member 30 can seal the connection part with the front-end | tip of the drain apparatus 3 which faced the ground surface, and can prevent the inflow of the air from the said connection part also at the time of pressure reduction by the vacuum pump 8. FIG. it can. Therefore, in the construction method using the connection member 30, the predetermined pressure reduced by the vacuum pump 8 can be maintained, and the drainage can be efficiently performed from the soft ground 2 within a predetermined period.

  Moreover, in the soft ground improvement construction method using the connection member 30, after driving the drain apparatus 3 in the soft ground 2 in the setting site, the connection member 30 is attached to the impermeable portion of the drain apparatus 3 exposed to the ground surface. Connecting. Therefore, according to the present construction method, one long drain device 3 in which a water-impermeable portion is formed by the hose 13 at a predetermined interval is wound in a roll shape and carried to the placing site, and the conventional construction can be performed. In addition, man-hours do not increase and work efficiency is not impaired.

  After connecting the connection member 30 to the impermeable portion of the drain device 3, the connection hole 44 of the joint body 33 and the attachment portion 5 of the water collecting pipe 4 are connected in an airtight manner. After all the connecting members 30 connected to the drain apparatus 3 placed are connected to the water collecting pipe 4, the pressure is reduced by the vacuum pump 8 connected to the drain pipes 6 connected to the plurality of water collecting pipes 4 ( (See FIG. 2). Thereby, the inside of the water collecting pipe 4 is depressurized, and the water in the ground of the soft ground 2 is discharged into the drain device 3.

  After draining the moisture in the soft ground 2 over a predetermined period and finishing the ground improvement, the tip of the drain device 3 facing the ground surface is cut, whereby the connecting member 30 is recovered and washed. It can be reused later.

DESCRIPTION OF SYMBOLS 1 Connection member, 2 Soft ground, 3 Drain apparatus, 4 Water collecting pipe, 5 Mounting part, 8 Vacuum pump, 10 Core material, 11 Filter, 12 Drain material, 13 Hose, 15 Insertion hole, 16 Water conveyance part, 17 Main body, 20 Taper part, 23 Adhesive, 24 Stapler, 25 Adhesive tape, 30 Connection member, 31 Joint piece, 32 Joint cover, 33 Joint body, 34 Flange part, 35 Insertion hole, taper part, 37 Fitting hole, 39 Locking step Part, 40 flange part, 41 screw hole, 43 contact surface part, 44 connection hole, 45 screw hole, 46 packing

Claims (9)

It is formed so as to have a hollow portion with a water permeable material, and is formed so as to have a water permeable member placed at a predetermined depth in soft ground and a hollow portion through which the water permeable member is inserted with a water impermeable material. Connecting a drain device having a predetermined length from the ground surface of the soft ground and an impervious member placed on the soft ground, and a water collecting pipe for collecting groundwater pumped up by the drain device. In the connection member,
An insertion hole into which the tip of the water permeable member of the drain device is inserted is formed at one end, and a water guide portion is formed at the other end that is continuous with the insertion hole and guides groundwater to the water collecting pipe. A main body on which the tip of the water-impermeable member adheres to the outer surface toward the end side,
The connecting member in which the main body is formed with a taper portion whose diameter is larger than the opening diameter of the water-impermeable member from the one end side toward the other end side.   The main body has a flat shape, the insertion hole having a substantially rectangular shape faces one end surface, the water guiding portion is formed on the other end surface, and the tapered portions are formed on both side surfaces provided in the longitudinal direction of the insertion hole. The connecting member according to claim 1 formed.   3. The main body, wherein both main surfaces adjacent to the both side surfaces on which the tapered portions are formed are bulged in the short direction of the insertion hole with the center position in the longitudinal direction as the thickest portion. Connecting member.   The connection member according to any one of claims 1 to 3, wherein an adhesive is applied to the outer surface of the one end side to which the water-impermeable member is attached.   The said main body is a connection member of any one of Claims 1-4 which connects the said water-permeable member and the said main body with a stapler after the said water-permeable member is inserted.   The connection member according to any one of claims 1 to 5, wherein the main body is sealed with the water-impermeable material by an adhesive tape after the water-impermeable material is attached. It is formed so as to have a hollow portion with a water permeable material, and is formed so as to have a water permeable member placed at a predetermined depth in soft ground and a hollow portion through which the water permeable member is inserted with a water impermeable material. A drain device comprising a water-impermeable member placed on the soft ground leaving a predetermined length from the ground surface of the soft ground, the tip of the water-impermeable member protruding into the ground surface, and into the soft ground A process of placing;
Inserting the water-permeable member of the drain device into the insertion hole of the connection member, and attaching the water-impermeable member to the connection member;
Connecting the connecting member to a water collecting pipe;
A step of depressurizing the inside of the water collecting pipe,
In the step of attaching the water-impermeable member to the connecting member, the water-impermeable member is covered with a tapered portion formed on the outer surface of the connecting member and having a diameter larger than the opening diameter of the water-impermeable member. How to improve the ground. The connection member includes a joint cover through which the tip of the drain device protruding to the ground surface of the soft ground is inserted, a joint piece to which the tip of the drain device is attached, and a joint that sandwiches the joint piece together with the joint cover The body,
The joint piece has an insertion hole into which one end of the water permeable member of the drain device is inserted at one end, and an outer surface on which the tip of the water impermeable member is attached from the one end side toward the other end side. The tapered portion is formed to expand from the one end side toward the other end side than the opening diameter of the impermeable member,
The joint cover is formed with a fitting hole for holding the water-impermeable member together with the outer surface of the joint piece by fitting the joint piece.
The joint body is formed with a water conduit connected to a water collecting pipe for collecting ground water pumped up by the drain device at the other end,
After the joint cover is inserted into the tip of the drain device, the water-permeable member is inserted into the insertion hole of the joint piece, and the outer surface of the joint piece is covered with the water-impermeable member.
The ground improvement method according to claim 7, wherein the joint piece connected to the drain device is clamped by the joint cover and the joint body.   The ground improvement method according to claim 8, wherein packing is interposed between the joint piece and the joint body.

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