JP4916395B2 - Drainage pipe set and drainage method - Google Patents

Description

  The present invention relates to a drainage pipe set for draining groundwater from a drainage borehole formed in a natural ground and a drainage method.

  When excavating a tunnel, if the groundwater level in the ground is high, a long drainage boring is generally performed in front of the face, and the groundwater level is lowered to a level where the face mirror is stable. However, it is difficult to keep the tunnel excavation cross section below the groundwater level, and it is very expensive, so there is actually some groundwater around the tunnel after excavation. In the sand layer, gravel layer, and low-strength sandstone layer, spring water continues through a slight gap in the shotcrete surface that was constructed after tunnel excavation, and fine particles from the natural ground flow into the tunnel along with the spring water. As a result, a gap is generated at the boundary between shotcrete and natural ground, or the strength of natural ground is deteriorated. There is a problem that the reinforcement of the tunnel becomes necessary, or the necessary tunnel cross-section is eroded, and re-excavation (re-excavation and concrete spraying, restoration of the wall surface of the mine wall with a lock bolt, etc.) becomes necessary. In such a case, if the geology is almost homogeneous, it is possible to greatly reduce the groundwater level after excavation by the well point method of installing and suctioning a strainer pipe for drainage in a borehole drilled downward. In the case where the aquifer is distributed at the top of the tunnel cross section, or is partially horizontal or inclined, the well point method of simply inserting the strainer pipe into the drilled hole is There was a problem that drainage could not be performed efficiently because air flowing in from the mouth side was sucked.

  To cope with this, attach two ring-shaped packers (tip packer, mouth packer) to the mouth side of the strainer tube, inject a water-stopping material into each ring packer, adhere to the drilling surface, and partition it. A water drainage method has been developed that further injects and cures a water-stopping material between the packer and the mouth packer, thereby preventing the inflow of air from the borehole mouth and improving the suction efficiency (see, for example, Patent Document 1).

However, this construction method requires two ring-shaped packers and a water-stopping material to be injected between the ring-shaped packers to cure them. If there is roughness, the tip packer and the borehole wall will not be in close contact with each other, and the water-stopping material injected between the ring packers will pass over the tip packer and reach the tip side of the strainer pipe. There was a problem that the drainage may be obstructed.
JP-A-5-187185

  The present invention provides a water drainage pipe set and a water drainage method that solves such problems of the prior art, can be applied quickly and easily even when there is a rough hole. With the goal.

  In order to achieve the above object, the present invention is a drainage pipe set for extracting groundwater from a drainage borehole formed in a natural ground, and has a filter in which a water passage hole is formed to prevent passage of earth and sand. A packer comprising: a drainage pipe; a tubular packer having a sealing portion that closes the distal end side; the distal end part being connected to the drainage pipe; and a connection part for connecting the drainage pipe and the packer. Is a reduced-diameter shape in which a part of the side wall of the tube is recessed toward the side wall facing it, and is an expansion tube type packer in which the recessed portion protrudes into a convex shape by internal pressure and expands in diameter. Provided is a drainage pipe set, wherein the sealing part is formed so that the sealing can be broken when necessary, and is not broken below a pressure required for expanding the diameter of the packer. (First invention).

  In order to achieve the above object, the present invention is also a drainage method for draining groundwater from a drainage borehole formed in a natural ground, wherein the water has a filter in which a water passage hole is formed and prevents passage of earth and sand. Preparing a drain pipe, a tubular packer whose front end side is sealed by a sealing portion and whose front end portion is connected to the drain pipe, and a connecting portion for connecting the drain pipe and the packer; The expansion tube type packer has a reduced diameter shape in which a part of the side wall of the tube is recessed toward the side wall facing the tube, and the recessed portion protrudes into a convex shape by internal pressurization and expands in diameter. The stopper is capable of breaking the seal when necessary, and is formed so as not to break below the pressure required for the diameter expansion of the packer. A bore hole is drilled in the drain pipe. A packer is connected and inserted into the bore hole from the drain pipe side, and after insertion, a liquid is pumped into the packer, the packer is expanded and expanded to be in close contact with the wall surface of the borehole, and then the sealing is performed. The present invention provides a water draining method characterized in that the sealing of the stopper is broken and the ground water is discharged through the drain pipe and the packer (second invention).

  In order to achieve the above object, the present invention further provides a drainage method for extracting groundwater from a drainage borehole formed in a natural ground, wherein the water has a filter in which a water passage hole is formed to prevent passage of earth and sand. A drain pipe, a tubular packer whose front end side is sealed by a sealing portion and whose tip is connected to the drain pipe, a connection portion for connecting the drain pipe and the packer, and a tip of the drain pipe A drilling bit that can be attached to the drainage pipe and a drive rod that can be connected to the rear end of the drainage pipe, and the packer has a contraction in which a part of the side wall of the pipe is recessed toward the side wall facing it. An expansion tube type packer having a diametrical shape and having an indented portion that protrudes into a convex shape by internal pressure and expands in diameter, and the sealing portion is capable of breaking the seal when necessary, and It is formed so as not to break below the pressure required for expansion. The drill bit is attached to the front end of the packer, the drive rod is connected to the rear end, and the drill bit is at the head by the driving force applied to the drive rod, A bore hole into which a drain pipe and a packer can be inserted is drilled, and then the drive rod is pulled out from the bore hole and removed from the rear end of the drain pipe, and the packer is attached thereto, and the drain pipe and the packer are attached. Inserted into the borehole, and after insertion, liquid was pumped into the packer, the packer was inflated and expanded to closely contact the wall surface of the borehole, and then the seal of the sealing portion was broken, and the water The present invention provides a water draining method characterized by discharging groundwater through a drain pipe and a packer (third invention).

  According to the first aspect of the present invention, it is possible to provide a drainage pipe set having the following effects. That is, the drainage pipe set is provided with a drainage pipe having a filter in which a water passage hole is formed and prevents passage of earth and sand, and a sealing portion that closes the distal end side, and the distal end is connected to the drainage pipe. A tubular packer and a connection part for connecting the drain pipe and the packer, so that the mouth side of the borehole is inserted by inserting both into a borehole drilled in a natural ground. Water can be stopped with a packer and drained through a drain pipe filter. In particular, the packer has a reduced diameter shape in which a part of the side wall of the tube is recessed toward the side wall facing the tube, and an expansion tube type in which the recessed portion protrudes into a convex shape and expands by internal pressure. Since it is a packer, if a fluid is pumped from the back end of the packer after being inserted into the borehole, the packer can be expanded and expanded to be brought into close contact with the wall surface of the borehole. Thereby, the water stop state can be obtained quickly without having to wait for the water stop material to harden. Moreover, since the sealing portion is formed so as to be able to break the seal when necessary and not to be broken below the pressure required for the diameter expansion of the packer, after expanding the diameter of the packer, If the sealing of the sealing portion is broken, the inside of the packer and the inside of the drain pipe can be immediately communicated. Therefore, the drainage construction using the drainage pipe can be performed quickly and easily. Further, since the packer is expanded and expanded by the pressure of the fluid, the water stopping action can be surely obtained even when the hole of the bore hole is rough.

  The sealing portion may be formed so as to break the sealing when a pressure exceeding the pressure required for expanding the diameter of the packer is applied from within the packer. According to this, since the diameter of the packer is expanded by pumping the liquid and then the liquid is pumped at a higher pressure, the sealing of the sealing portion can be broken, so that the construction can be performed more easily.

  The drainage pipe set is connected to a drilling bit that can be attached to the tip of the drainage pipe and a rear end of the drainage pipe instead of the packer when drilling, and transmits a driving force for cutting. And a drive rod that further includes a drive rod. As a result, a bore hole into which the drainage pipe and the packer can be inserted can be drilled in the natural ground with the drilling bit at the head by the driving force applied to the drive rod connected to the drainage pipe. Therefore, after that, if the drive rod is pulled out from the bore hole and removed from the rear end of the drain pipe, the packer is attached thereto, and the drain pipe and the packer are inserted into the bore hole as described above. Thus, the diameter of the packer and the subsequent steps can be performed.

  Further, the packer has a water stop disposed in the recessed portion in the reduced diameter state so as to fill a gap between the recessed portion remaining in a part of the original recessed portion and the wall surface of the borehole when the packer expands and expands in diameter. Means may be provided. If the expansion tube type packer expands and expands as a whole by internal pressure, the entire circumference is restored to a convex shape, but if the borehole diameter is small, the strength of the natural ground is high, the internal pressure is low. In some cases, a portion may remain concave. In this case, since the groundwater leaks through the concave portion without passing through the drain pipe filter, there is a possibility that a problem of outflow of fine particles in the natural ground may occur. On the other hand, when the packer is provided with the water stop means arranged in the recessed portion in the reduced diameter state, even if the concave portion remains at the time of the diameter expansion, the water stop means can be used as a gap between the concave portion and the wall surface of the borehole. To prevent groundwater leakage.

  In the second invention, the drainage pipe set according to the first invention is inserted into the borehole drilled in the natural ground, and the expansion and expansion of the packer by internal pressurization and the subsequent sealing part destruction are performed. Thus, groundwater is discharged through the drain pipe and the packer. Therefore, on the basis of the above-described operation described for the first invention, the water draining operation according to the natural ground conditions can be easily performed even when there is a rough hole.

  In the third aspect of the present invention, a drill bit that can be attached to the tip of the drain pipe, and a drive rod that can be connected to the rear end of the drain pipe, in addition to the drain pipe set of the first aspect of the invention. Prepare what you have. Then, attach the drilling bit to the tip of the packer and the drive rod to the rear end, and use this to drill a borehole in the ground, then remove the drive rod and attach the packer to the rear end of the drain pipe. After that, in the same manner as in the second aspect of the invention, the expansion and diameter expansion of the packer and the sealing part are broken, and the groundwater is discharged. Therefore, from the drilling of the borehole to the ground and discharging the groundwater can be performed consistently by the drainage pipe set, and the drainage can be performed more quickly and easily.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same or similar parts in the drawings may be denoted by the same reference numerals and description thereof may be omitted.

  FIG. 1 shows a drainage pipe assembly 1 in which a drainage pipe set according to an embodiment of the present invention is assembled. The drainage pipe set includes a drainage pipe 20, a tubular packer 30, and a connection portion 40.

  As shown in FIG. 2, the water drain pipe 20 includes a tubular pipe main body 200, and the pipe main body includes a shaft hole 21 that extends over the entire length, and a large number of side holes 22 that communicate with the shaft hole from the circumferential surface. Are formed, and these function as water passage holes. A tapered head 23 is fixed to the distal end of the tube main body 200 in order to facilitate insertion into the bore hole. The side hole 22 can have various shapes such as a circle, an ellipse, a polygon, and a slit. It is desirable that the drain pipe 20 has a filter function in order to prevent the outflow of fine particles that cause a decrease in strength or collapse of ground when passing groundwater. For this purpose, a filter is inserted into the drain pipe 20 or the size of the side hole 22 is limited, or the side hole 22 is covered with a filter material. When a filter is inserted into the drain pipe 20, the drain pipe 20 may be opened by omitting the head 23 at the tip. A joint member 24 for connection to the packer 30 is formed on the outer peripheral surface of the rear end portion of the pipe body 200. As shown in FIG. 4, the joint member 24 has a short cylindrical shape, is provided with a flange 241 at the center portion in the longitudinal direction, is provided with a male screw 242 at the rear portion, and the front portion 243 is fitted into the pipe body 200 and fixed. Has been. As a material constituting the drain pipe 20, various materials such as metal and plastic can be used. In particular, in order to be able to force the packer into the borehole by striking or strong pressure from heavy machinery, it is desirable that the tube body 200 be made of metal, particularly steel tubes.

  The filter mounted in the shaft hole 21 of the drain pipe 20 can be, for example, a filter 25a along the inner surface of the side wall of the pipe, as shown in FIG. The filter 25a uses a cylindrical or sheet-like net formed in a cylindrical shape, and the rear end is used as a front part 243 and a front end part of the joint member 24 as shown in FIG. Can be fitted to the support plate 251 and fixed by bonding, winding a wire, or the like. Alternatively, as shown in FIG. 6, instead of the joint member 24, the rear end is fixed to a ring 252 having an outer diameter substantially the same as the inner diameter of the pipe main body 200, and this is inserted into the pipe main body 200 and fitted. It may be fixed by adhesion or the like. In addition, as shown in FIG. 7, it is also possible to use a filter 25b in which a solid net-like body has a columnar shape having an outer diameter substantially the same as the inner diameter of the tube main body 200. This columnar filter can be formed as a three-dimensional network using a plant fiber, a chemical fiber, a plastic or metal sheet material, a rod material, or a tube material.

  When the filter is provided in the side hole 22, for example, as shown in FIG. 3, a counterbore portion 24 having a slightly large diameter is formed shallowly outside the side hole 22, and the side hole 22 is blocked by the counterbore portion 24. A circular filter 26 may be fitted and fixed to the counterbore 24. In this case, the filter 26 can be made of, for example, a steel mesh.

  As shown in FIG. 8, the packer 30 is obtained by fixing a front end sleeve 32 and a rear end sleeve 33 to each end portion of the tube main body 31. 8A is a front view of the packer 30, FIG. 8B is a sectional view taken along the axis, FIG. 8C is a sectional view taken along the line cc of FIG. 8D, and FIG. 8D is the tip sleeve 32 and the sealing portion 36. FIG. The packer 30 has a reduced diameter shape in which a part of the side wall of the tube 31 is recessed toward the side wall facing the tube 31.

  The packer 30 is manufactured as follows according to the steps (1) to (4) in FIG. First, a cylindrical tube 31 shown in (1) is prepared. This is pressed from one side and flattened as in (2). The both sides of the flattened tube 31 are rounded so as to be close to each other, and the shape of (3) is obtained. Then, as shown in (4), the end sleeve 32 and the rear end sleeve 33 are covered so that the respective end portions are narrowed, and the front end portion of the tube main body 31 and the inner surfaces of these sleeves are fixed by welding. The leading end sleeve 32 and the trailing end sleeve 33 and the tube body 31 can be fixed by welding, shrink fitting, screwing with a screw, or the like.

  As shown in FIG. 8 (d), the distal end sleeve 32 includes a base portion 322 that is tightly fitted to the distal end portion of the packer 30, and a threaded portion 323 that extends from the base portion toward the distal end side with a slightly narrower diameter. I have. The threaded portion 323 is provided with a male screw portion 324 on the outer peripheral surface and a female screw 325 portion on the inner peripheral surface. The male screw portion 324 and the female screw portion 325 are respectively screwed into the connecting portion 40 and the sealing portion 36.

  As shown in FIG. 8D, the sealing portion 36 includes a screw portion 361 that is screwed into the tip sleeve 32, and a head portion 362 provided on the tip end side of the screw portion 361. The sealing portion 36 is formed so as to be unscrewed when a predetermined pressure is applied from the inside while being screwed to the distal end sleeve 32. In this embodiment, the sealing portion 36 is made of metal, plastic, or the like, so that the screw portion 361 is detached from the female screw portion 325 by breaking or elastic deformation at a predetermined pressure. In order to ensure that the threaded portion 361 breaks at a predetermined pressure, a hollow portion 363 can be formed inside the threaded portion 361 as shown by a broken line in FIG. Note that the structure of the sealing portion 36 that breaks the seal with a predetermined pressure is such that the member that closes the opening portion of the distal end sleeve 32 is bonded, welded, and one-touch joint in addition to the one that causes disengagement at the screwed portion as in this example. (Fitting type pipe joint with a retaining mechanism) or the like, or one in which the tip sleeve 32 and its opening closing part are integrally molded, etc., can be bonded, welded, joint part or sealing member The structure itself can be destroyed.

  Based on the above structure, the packer 30 is an expansion tube type packer in which the recessed portion protrudes into a convex shape and expands in diameter by internal pressure. As a material constituting the tube body 31, various materials such as metal and plastic can be used. In particular, in order to be able to force the packer into the borehole by striking or heavy pressure from a heavy machine, it is desirable that the pipe body 31 is made of metal, and it is particularly desirable to use a steel pipe.

  The internal pressurization of the packer 30 can be performed by pumping a liquid such as water from the rear end. The liquid supply pressure to the packer is determined in consideration of the pressure necessary for the expansion and expansion of the packer, the pressure necessary for the consolidation of the peripheral portion of the borehole due to the expansion of the packer. For example, when the pressure required for the expansion and expansion of the packer is 20 MPa, and when it is necessary to consolidate the ground around the bore hole at 5 to 10 MPa at the time of expansion, the pressure at the time of pumping is usually 25 to 30 MPa. Is done.

  In this embodiment, the connection portion 40 is formed by providing female screw portions 44 and 46 on the inner peripheral walls on both sides of the tubular member 41 as shown in FIG. The female screw portion 44 can be screwed with the male screw 24 of the drain pipe 20, and the female screw portion 46 can be screwed with the male screw 320 provided on the tip sleeve 32 of the packer 30. The connection part 40 and the drain pipe 20 and the packer 30 can be connected by various means such as bonding, welding, and the like in addition to screwing.

  The drainage method according to the present invention is performed using the above-described drainage pipe set, and typical examples of the drainage method include a well point method, and further include a rock bolt combined well point method. . FIG. 11A is a longitudinal section along the excavation direction schematically showing the tunnel excavation site, and FIG. 11B is a sectional view taken along the line CC of FIG. 11A. As illustrated, the tunnel T is dug while forming an upper half G1, a lower half G2, and an invert G3 with respect to the natural ground M. In the case of the well point method, the drainage pipe assembly 1 is constructed from the upper half board G1 and the lower half board G2 downward (shown by solid lines) or obliquely downward (shown by broken lines in the figure). On the other hand, in the case of the well point method also used as a lock bolt, as shown in FIG. 12 (a), it is constructed at the same position as the position where a normal lock bolt is constructed, and as shown in FIG. It is also possible to increase the drainage efficiency of groundwater by constructing it at a position slightly downward (shown by a solid line) from the position where the lock bolt is installed (shown by a broken line).

  Hereinafter, an example of the method of the present invention that can be applied to both of the above methods will be described with reference to FIGS. First, as shown in FIG. 13 (1), a borehole B is formed by boring forward from a face where the drainage is necessary, for example, from the facet mirror surface K, at a tunnel excavation work site. Thereby, the spring water W flows out from the natural ground M as shown by the arrow. On the other hand, the drain pipe 20, the packer 30, and the connecting portion 40 shown in FIGS. 1 to 10 are connected to form the drain pipe assembly 1.

  Then, as shown in FIG. 13 (2), with the head 23 at the head, the drainage pipe assembly 1 is inserted into the bore hole B, and the head end is advanced until the front end of the rear end sleeve 33 fitted in the packer 30 contacts the face mirror surface K. Let Then, the water injection tube Tp connected to the high-pressure water pump is connected to the rear end sleeve 33 via the attachment A. FIG. 14A shows a state of the packer 30 inserted in the bore hole B in a cross-sectional view. Note that a pressure gauge, a valve, or the like for measuring the spring pressure can be attached to the rear end sleeve 33 or the attachment A as necessary.

  Next, water is pumped from the high water pressure pump to the packer 30 at a predetermined pressure through the water injection tube Tp. As a result, as shown in FIG. 13 (3), the packer 30 expands and expands, contacts the wall surface of the bore hole B, and consolidates the natural ground around the bore hole. FIG. 14 (2) shows this expanded state, and the arrows in the figure indicate the expansion pressure of the packer 30 and the reaction force from the natural ground against it.

  Then, water is fed from the high water pressure pump to the packer 30 at a higher pressure. Thereby, the seal | sticker of the sealing part 36 is destroyed and the packer 30 and the drain pipe 20 will be in a communication state. As a result, groundwater is led out through the drain pipe 20 and the packer 30. Here, the attachment A and the water injection tube Tp are removed and replaced with the water guide tube Td. Thereby, as shown in FIG. 13 (4), the derived water can be discharged to a predetermined place through the water guide tube Td.

  The drainage may be discharged depending on the groundwater flow output, or may be performed by replacing the water guide tube Td with a suction hose and connecting a water absorption pump to apply a suction force. In the case of applying a suction force, it is desirable that the contact surface between the packer 30 and the inner wall surface of the borehole B be airtight or close to the state. It is desirable to set the diameter of 30 large. Thereby, when a suction force is applied, inflow of air from the mouth side of the borehole B is prevented, and suction of groundwater is efficiently performed.

  When the drainage of the groundwater is finished, the water guide tube Td and the suction hose are removed from the rear end sleeve 33, and the water draining operation is finished (FIG. 13 (5)). Further, if necessary, a sealing material is injected into the drainage pipe assembly 1 from the rear end sleeve 33 in order to close the water passage after drainage, and is cured. Furthermore, if necessary, the drainage pipe assembly 1 can be left in the bore hole B to function as a lock bolt. For this purpose, the drainage pipe assembly 1 may be simply left, but in order to improve the locking function, the grout hose Tg is connected to the rear end sleeve 33 and the packer 30 and the drainage pipe 20 are connected. Inject a fixing material such as cement milk. As a result, the fixing material is injected into the bore hole B from the side hole 22 of the drain pipe 20. Since the mouth side of the bore hole B is stopped by the packer 30, the fixing material fills between the drain pipe 20 and the wall of the bore hole B (FIG. 13 (6)). Therefore, if the fixing material is hardened, the drainage pipe assembly 1 is fixed on the ground and functions as a lock bolt.

  In this way, according to the above construction method, the drainage of the natural ground can be performed quickly and easily, and even when there is a rough hole, the water stopping action can be reliably obtained by the expansion and expansion of the packer. Actually, the operations from the insertion of the drain pipe assembly 1 to the formation of the water stop state by the packer 30 could be performed in about 10 seconds per meter of packer. In the conventional method described above (two ring-shaped packers are attached to the strainer tube, and a water-stopping material is injected and cured between each ring-shaped packer and the packer), it takes about 4 minutes from the insertion of the tube to the formation of the water-stop. Therefore, the effect of the present invention is extremely high.

  If packers with different lengths are prepared, it is possible to select and use packers according to the situation at the site, and respond quickly when unexpectedly long water stoppage length is required. can do.

  Depending on the borehole diameter and ground strength, a part of the packer 30 may remain concave, and there may be a problem that groundwater leaks out from the part without passing through a filter. On the other hand, the packer 30 can be provided with the water stop means 34 arrange | positioned at the recessed part in a diameter-reduced state, as additionally shown in FIG. As the water stop means 34, a sponge-like material such as neoprene sponge rubber, a viscoelastic material such as silicon rubber, a fiber or polymer material having water expandability, a hardened material that is crushed when an external force is applied and fragments are housed inside Resin capsules that are cured by reacting with the material, natural rubber or synthetic rubber, and a mixture of these and cementitious materials can be used. Moreover, the water stop means 34 may be provided in a part of the longitudinal direction of the packer 30 as shown in the figure, or may extend continuously over the entire length.

  In order to arrange the water stop means 34 in the packer 30, as shown in FIG. 9 (2), after the pipe body 31 is flattened, the water stop means 34 is placed on the pipe body 31, and both side edges of the pipe 31 are placed. Round it up so that it has the shape shown in Fig. 9 (3). At this time, the water stop means 34 is made to close and hold the concave portion of the packer 30 or, if not, the movement within the concave portion can be performed by means such as adhesion and adhesion as necessary. To prevent. By providing the water stop means 34 in this way, the packer 30 is provided with the water stop means 34 in the borehole B as shown in FIGS. 15 (1) and 16 (1). When inserted and expanded in diameter, the state shown in FIGS. 15 (2) and 16 (2) is obtained. In other words, even when a part of the packer 30 is expanded in diameter, even if a part of the packer 30 remains concave, the water stop means 34 fills the gap between the concave part and the wall surface of the borehole, thereby preventing leakage of groundwater.

  Next, a description will be given of an embodiment of the water drainage construction method by a self-piercing method using a drainage pipe set capable of drilling a borehole in a natural ground with reference to FIGS. 17 to 19. According to this construction method, from the drilling of the borehole to the discharge of groundwater can be performed consistently by the drainage pipe set, and drainage can be performed more quickly and easily. FIG. 17 shows a water draining pipe set used in this construction method. This drainage pipe set is different from that shown in FIG. 1 in that a perforation bit 29 that can be attached to the tip of the drainage pipe 20, and a rear end of the drainage pipe 20 instead of the connecting portion 40 and the packer 30. A connecting sleeve 50 and a drive rod 60 that can be connected are further provided. The bit 29 includes a through hole 290 for ejecting water from the tip during drilling. Further, the connecting sleeve 50 has a cylindrical shape similar to that of the connecting portion 40 and has an internal thread formed on the inner surface, and the drain pipe 20 can be screwed to the front and the drive rod 60 can be screwed to the rear. A water supply tube Ts extending through the entire length of the drain hole 20 is connected to the shaft hole of the connecting sleeve 50. The drive rod 60 has the same or longer dimension as the packer 30, has a male thread portion for screwing with the connecting sleeve 50 at the front end portion, and extends in the axial direction to allow water supply to the bit. It has a through hole.

  For construction, first, the drainage pipe 20 is connected to the front side of the connecting sleeve 50, and the drive rod 60 is connected to the rear side to assemble the drilling assembly 1a. The bit 29 of the drain pipe 20 is connected to a water supply source through the water feed tube Ts, the connecting sleeve 50 and the drive rod 60 in the drain pipe 20.

  Using this drilling assembly 1a, as shown in FIG. 18 (1), a bore hole H is drilled from a tunnel excavation surface such as a face mirror surface K or the like. This is performed by rotating and pushing the drive rod 60 and advancing the drilling assembly 1a while jetting water from the through hole 290 with the bit 29 as the head. By the injection of water from the bit 29, slime that hinders perforation can be removed from the perforated portion. As shown in FIG. 18 (2), the bore hole is drilled to a depth that allows the drainage pipe assembly 1a to be inserted later to be accommodated up to the rear end.

  Once drilled to a predetermined depth, the drilling assembly 1a is retracted until the connecting sleeve 50 is exposed from the bore hole B (FIG. 18 (3)), and the connecting sleeve 50 is removed from the drain pipe 20 together with the drive rod 60 (FIG. 18 (4)), and pulls out the water supply tube Ts (FIG. 18 (5)). At this stage, it is also possible to insert a filter into the shaft hole of the drain pipe 20. Then, the connection part 40 is attached to the drain pipe 20 (FIG. 18 (6)), the packer 30 is attached to the rear side of the connection part 40, and it is set as the drain pipe assembly 1 (FIG. 19 (7)). At this time, the attachment A is attached to the packer 30 as necessary. In particular, when the hole wall is not self-supporting, it is necessary to hit or rotate when the drainage pipe assembly 1 is subsequently inserted. In such a case, the attachment A is attached.

  Thereafter, the drainage pipe assembly 1 is advanced and inserted into the bore hole B up to the rear end of the packer 30. (FIG. 19 (8)). In this state, the water injection tube Tp is attached to the attachment A, and the packer 30 is inflated and expanded in diameter by pumping water through the water injection tube Tp (FIG. 19 (9)). As a result, the packer 30 comes into close contact with the wall surface of the bore hole B.

  Further, water is supplied from the water injection tube Tp at a higher pressure, and the sealing at the tip of the packer 30 is broken (FIG. 19 (10)). The water supply for the expansion of the packer and the destruction of the sealing portion may be performed in each stage or may be performed in a series of water supply operations. Thereby, the packer 30 and the drain pipe 20 are in communication with each other, and groundwater is led out. After this, it is the same as the process described with FIG. 13, and can be discharged to a predetermined place through the water guide tube Td (FIG. 19 (12)). If necessary, the groundwater can be discharged by suction. . When the drainage of the groundwater is finished, the drainage pipe assembly 1 can be made to function as a lock bolt if necessary. In order to enhance the function, the grout hose Tg is connected to the packer 30 and the drainage pipe 20. Then, a fixing material is supplied into the bore hole B and cured (FIG. 19 (12)).

  The present invention is not limited to the above embodiment, and various modifications can be made. In the case of using the self-drilling assembly 1a for construction, the connecting portion 40 is also used as the connecting sleeve 50 by making the male screw at the tip of the drive rod 60 and the male screw of the tip sleeve 32 of the packer 30 the same. be able to. Further, by increasing the bending strength and rigidity of the packer 30 in the reduced diameter state, the packer itself can also be used as a drive rod.

  The connecting portion 40 can be pre-joined with either the drain pipe 20 or the packer 30. Alternatively, the threaded portion 323 of the tip sleeve 32 of the packer 30 is formed in a cylindrical shape, and an internal thread is provided on the inner surface. It may be directly screwed into the male screw 24 at the rear end of the drain pipe 20.

  In addition to increasing the pressure in the packer, the sealing part is broken, and by inserting a bar piece or the like from the back end of the packer and pressing it firmly, the constituent parts of the sealing part are removed from the front end of the packer, or the It can also be done by destroying the component itself.

It is a front view of the drainage pipe assembly in which the drainage pipe set concerning one embodiment of the present invention was assembled. It is a front view of the drain pipe shown in FIG. It is a longitudinal cross-sectional view which expands and shows the side hole vicinity of the drain pipe of FIG. It is a longitudinal cross-sectional view which shows the example which attached the filter to the drain pipe shown in FIG. It is a front view which shows an example of the filter used for the drain pipe of FIG. It is a front view which shows the other example of the filter used for the drain pipe of FIG. It is a longitudinal cross-sectional view which shows the other example which attached the filter to the drain pipe shown in FIG. It is a figure which shows the packer shown in FIG. 1, (a) is a front view, (b) is a longitudinal cross-sectional view, (c) is a cross-sectional view along the cc line of (b), (d) is a sealing part. It is a longitudinal cross-sectional view. It is explanatory drawing which shows the manufacturing process of the packer shown in FIG. It is a figure which shows the longitudinal cross-section of the connection part shown in FIG. 1 with a drain pipe and a part of packer. It is the schematic of the tunnel excavation site which shows one application example of this invention construction method, (a) is a vertical side view, (b) is a cross-sectional view which follows the CC line of (a). It is a cross-sectional view which shows roughly the tunnel excavation site which shows the other application example of this invention construction method. It is explanatory drawing which shows order for one Embodiment of this invention drainage method using the pipe set for drainage shown in FIG. 1 later on. It is sectional drawing which shows two steps of the construction condition in the drainage method shown in FIG. It is explanatory drawing which shows order for other embodiment of the drainage method concerning this invention later on. It is sectional drawing which shows two steps of the construction condition in the drainage method shown in FIG. It is a front view of the pipe set for drainage concerning other embodiments of the present invention. It is explanatory drawing which shows order for the first half part of one Embodiment of this invention draining method using the pipe set for draining shown in FIG. 17 later on. It is explanatory drawing which shows the latter half part of one Embodiment of this invention drainage method using the drainage pipe set shown in FIG. 17 later on in order.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drain pipe assembly 1a Assembly for drilling 20 Drain pipe 22 Side hole 25a, 25b, 26 Filter 29 Bit 30 Packer 34 Water stop means 36 Sealing part 40 Connection part 50 Connection sleeve 60 Driving rod
Tp Injection tube B Borehole

Claims (8)

A drainage pipe set for extracting groundwater from a drainage borehole formed in a natural ground,
A drain pipe having a filter in which a water passage hole is formed and preventing passage of earth and sand; a tubular packer having a sealing portion that closes the distal end side and connected to the drain pipe; and the drain pipe And a connection for connecting the packer,
The packer is an expansion tube type packer having a reduced diameter shape in which a part of the side wall of the tube is recessed toward the side wall facing the tube, and the recessed portion protrudes into a convex shape and expands by internal pressure. Yes,
The drainage pipe set, wherein the sealing part is formed so that the sealing can be broken when necessary, and is not broken below a pressure required for expanding the diameter of the packer. 2. The water according to claim 1, wherein the sealing portion is formed so as to break the sealing when a pressure exceeding a pressure required for expanding the diameter of the packer is applied from within the packer. Tube set for punching. A drilling bit that can be attached to the tip of the drain pipe, and a drive rod that transmits a driving force for cutting connected to the rear end of the drain pipe instead of the packer when drilling. The drainage pipe set according to claim 1 or 2, characterized by the above. The packer has a water stop means disposed in the recessed portion in the reduced diameter state so as to fill a gap between the recessed portion remaining in a part of the original recessed portion and the wall surface of the borehole when the packer expands and expands in diameter. The drainage pipe set according to any one of claims 1 to 3, wherein the drainage pipe set is provided. A drainage method for extracting groundwater from a drainage borehole formed in a natural mountain,
A drain pipe having a filter in which a water passage hole is formed and preventing passage of earth and sand, a tubular packer whose tip side is sealed by a sealing portion and the tip portion is connected to the drain pipe, the drain pipe, A connecting portion for connecting the packer, and the packer has a reduced diameter shape in which a part of the side wall of the tube is recessed toward the side wall facing the tube, and the recessed portion is protruded by internal pressure. An expansion tube type packer that expands and expands into a shape, and the sealing portion is formed so as to be able to break the seal when necessary and not to break below the pressure required for the diameter expansion of the packer. It is supposed to be
Drill a bore hole in the ground with a slightly larger diameter than the packer,
Connect the packer to the drain pipe and insert it into the bore hole from the drain pipe side,
After inserting, the liquid is pumped into the packer, and the packer expands and expands to closely contact the wall surface of the borehole,
Then destroy the sealing of the sealing part,
A draining method characterized by discharging groundwater through the drain pipe and packer. A drainage method for extracting groundwater from a drainage borehole formed in a natural mountain,
A drain pipe having a filter in which a water passage hole is formed and preventing passage of earth and sand, a tubular packer whose tip side is sealed by a sealing portion and the tip portion is connected to the drain pipe, the drain pipe, A connecting portion for connecting a packer, a drilling bit attachable to a tip of the drain pipe, and a drive rod connectable to a rear end of the drain pipe are prepared, and the packer is a side wall of the pipe It has a reduced-diameter shape in which a part of is recessed toward the side wall facing this, and is an expansion tube type packer in which the recessed portion protrudes into a convex shape by internal pressurization and expands, and the sealing portion is The seal can be broken when necessary, and is formed so as not to break below the pressure required for expanding the diameter of the packer.
Attach the drilling bit to the front end of the packer, connect the drive rod to the rear end,
With the driving force applied to the driving rod, the drilling bit is headed, and a bore hole into which the drain pipe and packer can be inserted is drilled in a natural ground,
Thereafter, the drive rod is pulled out from the bore hole and removed from the rear end of the drain pipe, and the packer is attached thereto,
Inserting the drain pipe and the packer into the borehole;
After inserting, the liquid is pumped into the packer, and the packer expands and expands to closely contact the wall surface of the borehole,
Then destroy the sealing of the sealing part,
A draining method characterized by discharging groundwater through the drain pipe and packer. The sealing destruction of the sealing portion is performed by pumping liquid into the packer at a higher pressure after expansion and diameter expansion of the packer by liquid pumping. Water draining method. As the packer, using a packer provided with water stop means arranged in the recessed portion,
The water stop means fills a gap between the concave portion remaining in a part of the original concave portion and the wall surface of the bore hole when the packer expands and expands due to liquid pumping. The water draining method according to any one of 5 to 7.