JP4442882B2 - Construction method of element pipe and underground structure - Google Patents

Description

  In the present invention, a plurality of element pipes that are arranged in the ground to form a peripheral wall of an underground structure, and a tunnel, an underground parking lot, and a tunnel construction planned ground are surrounded to suppress ground deformation before tunnel excavation. It is related with the construction method of underground structures, such as a surrounding wall constructed | assembled.

  Conventionally, as shown in the cross-sectional view of FIG. 9, there is a method for constructing the underground structure 4 by horizontally arranging a plurality of steel elements 2 (2 </ b> A, 2 </ b> B, 2 </ b> C) without excavating the underground 1. Known (see Patent Documents 1 and 2, etc.).

  In this method, first, the first steel element 2A is pushed and arranged from behind the excavation hole 1a excavated in a circular shape by an excavator. The gap between the outer surface of the steel element 2A and the excavation surface is filled with a filler 3 having a strength that can be excavated later by an excavator to prevent the excavation surface from collapsing.

  Then, next to the steel element 2A arranged in advance, another steel element 2B is propelled while using it as a guide. Thus, the underground structure 4 is constructed by arranging the steel elements 2B, 2C,.

  This steel element 2 has a quadrangular view (2A) or a cross section by a plate-like outer shell 2a, 2a disposed on the ground 1 side and a blocking portion 2b, 2b connecting the outer shells 2a, 2a. It is formed in a U-shape (2B, 2C).

  Further, C-shaped joints 2c and 2c having a substantially C-shaped cross-section are formed at both ends of the outer shell 2a of the element pipe 2A, and the C-type joints 2c and 2c of the element pipe 2B arranged adjacent to each other The two are connected by meshing.

  The connection between the C-type joints 2c and 2c is performed by inserting a part of the other C-type joint 2c into the substantially C-shaped cavity of one C-type joint 2c. Since there is almost no gap, the connection is strong.

On the other hand, an underground structure that forms a peripheral wall of a tunnel or underground space by connecting a plurality of such steel elements 2 is also known (see Patent Document 2).
JP 2000-120373 A (FIG. 3, paragraphs 0011 to 0019) JP 2001-214699 A (FIG. 3, paragraphs 0001 and 0002)

  However, in the method of connecting the steel elements 2A and 2B by meshing the C-shaped joints 2c and 2c described above, there is almost no gap in meshing, so that the resistance when pushing the steel element 2B is large.

  In particular, it is difficult to absorb the displacement of the position due to the construction error of the steel element 2A previously disposed, and to dispose the steel element 2B to be disposed later at an accurate position. Moreover, even if rolling occurred in the steel element 2B during propulsion, it was difficult to suppress it.

  Since the connection direction is severely restricted, it is possible to perform only a straight construction, and it is difficult to construct a tunnel having a curved portion that curves in the middle of stretching.

  Furthermore, if the element pipe 2B is forcibly inserted while foreign matter such as earth and sand is clogged in the cavity of the C-type joint 2c, excessive stress is generated in the C-type joint 2c and the element pipes 2A and 2B, resulting in plastic deformation. , You may not be able to continue the promotion.

  Accordingly, the present invention provides an element pipe that can easily cope with curved portions, construction errors, and the like, and that can suppress rolling during propulsion, and a method for constructing an underground structure using the element pipe. It is an object.

  In order to achieve the object, the invention according to claim 1 is arranged such that when the peripheral wall is formed in the ground, it is arranged for each excavation hole by the excavator along the peripheral wall position, and adjacent ones are connected to each other. A cylindrical element tube forming the peripheral wall of the annular body, wherein the cylindrical body is inscribed in the excavation hole, and a groove portion having a concave cross section that is open to the outside is formed on a first side surface. It is an element tube formed by protruding a pair of engagement brackets outward at an interval substantially equal to the width of the groove.

Here, between the air within sandwiched between outer shell the grooves forming the cylindrical body, along the outer shell of the hollow portion for injecting the water stopper forming material in the longitudinal direction of the cylindrical body extending Ru is set.

Then, in the said shell in communication with the front Symbol hollow section, the through portion for passing the soil improvement agent as the water-stop portion forming material injected into the inside is formed.

Also, method for constructing an underground structure of the present invention is a method for constructing underground structures to form the peripheral wall using multiple said elements tube, underground arbitrary position corresponding to the peripheral wall position Is drilled by an excavator, and the element pipe is disposed by being pushed into the excavation hole, and the excavator is again dug along the groove portion of the element pipe that has been previously disposed, and is adjacent to the preceding element pipe. Forming an excavation hole, and engaging the engagement bracket of the other element pipe with the groove portion while inserting the element pipe into the excavation hole; and inserting an injection pipe into the hollow portion And a water stop portion forming step of forming a water stop portion by altering the underground adjacent to the groove portion by the water stop portion forming material injected into the injection pipe, and the element pipe arranging step and the water stop portion. Part formation process By sequentially or in parallel performed repeatedly, characterized by arranging the element tube in succession.

  According to the first aspect of the present invention configured as described above, the pair of engaging brackets of the other element tube disposed adjacent to each other are engaged with and connected to the groove formed in one element tube. Can do.

  For this reason, the element tubes can be connected to each other without relatively rotating (rolling). Moreover, since it can connect only by engaging surfaces, the restriction | limiting of a connection direction is loose and can respond easily to the construction of a curve part, and a construction error.

  And the looseness in the underground in which the said element pipe | tube is arrange | positioned can be suppressed to the minimum by increasing the area which inscribes the said cylinder to the said excavation hole. Here, inscribed means that at least a part of the cylindrical body is in contact with the excavation surface of the excavation hole.

Further, the hollow portion for injecting a pre Kitomesui portion forming member is previously formed.

  For this reason, the said water stop part forming material can be easily inject | poured, and a water stop part can be rapidly formed in the outer side of an element pipe | tube.

Then, the pre-Symbol hollow portion the soil improvement material, which is injected into the through-portion for discharging the ground side is previously formed.

  For this reason, a ground improvement material can be easily inject | poured into the ground which forms the said water stop part.

Further, the ground by the groove elements tube arranged by previous row, propelled while engaging the engagement bracket element tube be disposed adjacent to repeat the promotion process element tube by this engagement Build a structure.

  For this reason, it is possible to easily arrange the trailing element tube that is pushed into the ground later at an accurate position. Further, since the surfaces are merely engaged with each other, the groove portion is closed when the succeeding element tube is propelled so that excessive stress is not generated in the connecting portion and plastic deformation is not caused.

Further, the water stopper forming material injected through the front Symbol hollow portion, wherein by alteration of the ground adjacent to the groove to form a waterproof part.

  For this reason, the said water stop part can be easily formed in the connection part of the said element pipes, and water can be reliably stopped.

  In addition, since the water stoppage can be improved, underground structures can be safely constructed even in places with large earth pressure and water pressure such as deep underground.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  The same or equivalent parts as those in the conventional example will be described with the same reference numerals.

  FIG. 1 is a view showing a connecting portion between element tubes 7 and 9 according to the present embodiment, and FIG. 2 is constructed by connecting a plurality of element tubes 7, 9, 11, 12, 13,. A cross-sectional view of the underground structure 5 is shown.

  First, the configuration of the element tube 9 of the present embodiment will be described.

  In the element tube 9 of the present embodiment, most of the side surface is formed by the outer shell 9a that forms a cylindrical body. On this side surface, a groove section 90 having a concave cross section extends continuously in the longitudinal direction, and the outer shell 9a is formed in a substantially C-shaped cross section.

  The groove portion 90 is a groove having a substantially rectangular cross section that opens to the outside, and is formed by a bottom surface portion 9c and side surface portions 9d and 9d that are erected on both side edges. The bottom surface portion 9c is formed, for example, as a plane substantially orthogonal to the direction in which the element tube 9 is connected, and the side surface portions 9d and 9d are erected so as to be approximately orthogonal to the bottom surface portion 9c.

  Moreover, the rigidity of the 1st side surface which provided the groove part 90 can be improved by extending the both ends of the bottom face part 9c so that between the inner side surfaces of the said outer shell 9a may be connected. That is, the side surface portions 9d and 9d are erected on the inner side of the end portion of the bottom surface portion 9c so that the cross section of the intersecting portion has a substantially T-shape.

  Further, a reinforcing member 9e such as a rib is attached to the inner side surfaces of the outer shell 9a and the bottom surface portion 9c, and the element tube 9 is reinforced to have a structure capable of withstanding earth pressure and water pressure.

  A pair of engagement brackets 9f and 9f are formed on the other side surface of the cylindrical body. The positional relationship between the engagement brackets 9f, 9f and the groove portion 90 varies depending on which direction the element tube is connected and in which direction the element tube is connected.

  Here, description will be made on the assumption that the element tube 9 is connected to the leading element tube 7 provided with the groove portions 70 on both sides. The leading element pipe 7 is a special-shaped element pipe, and the leading element pipe 7 is used as a leading pipe, and element pipes 9 and 11 are connected to both sides as shown in FIG.

  The pair of engaging brackets 9 f and 9 f are members that are engaged with the groove portions 70 of the leading element tube 7. The engagement brackets 9f and 9f can be formed by attaching a steel plate having a substantially L-shaped cross section to the outer surface of the outer shell 9a.

  Here, the pair of engagement brackets 9f and 9f are attached so that one side surface of the L-shape faces the side surface portions 7d and 7d so as to be substantially equal to the width of the groove portion 70.

  The engagement brackets 9f and 9f formed so as to protrude to the outside of the outer shell 9a are fitted into the recessed groove portion 70, whereby the element tube 9 is engaged with the leading element tube 7.

  Further, the guide member 8 according to the present embodiment has a longitudinal direction in the inner space of the element tube 9 surrounded by the outer shell 9a, the side surface portion 9d, and the bottom surface portion 9c extending outward from the side surface portion 9d. It extends along.

  The guide member 8 is a tubular body having a substantially circular cross section in which a hollow portion for inserting an injection tube 8b described later is formed, and extends along the outer shell 9a.

  FIG. 6 is an enlarged cross-sectional view around the guide member 8 at the connecting portion between the leading element tube 7 and the element tube 9. As shown in this figure, in the outer shell 7a, the ground improvement material 10a as the water stop portion forming material injected into the guide member 8 through the injection pipe 8b is discharged to the underground 1 side. A penetrating portion 8a is formed.

  Then, the penetrating portion 8 a and the side surface of the guide member 8 are communicated so that the ground improvement material 10 a injected into the guide member 8 is discharged into the ground 1. The through portion 8a is formed in a circular shape or a slit shape. In addition, the ground improvement material 10a that has been discharged can be expanded toward the element tube 9 by being formed in a direction that is inclined toward the element tube 9 that is disposed adjacently.

  A cement-based solidifying material, a water glass-based injection material, or the like can be used for the ground improvement material 10a. By injecting the ground improvement material 10a into the underground 1, the underground 1 becomes the water stop portion 10 having a low permeability coefficient. Altered.

  Furthermore, the penetration part 8a is formed over the full length of the leading element pipe | tube 7 by a predetermined space | interval, as shown in FIG. By doing so, the water stop portion 10 can be continuously formed in the longitudinal direction of the leading element tube 7.

  Next, the construction method of the underground structure 5 as shown in FIG. 2 will be described, and the operation of this embodiment will be described.

  First, as shown in FIG. 3, the underground 1 is excavated into a cylindrical shape by a cylindrical excavator 6. A bit 6a is provided on the front face plate 6b of the excavator 6, and the underground 1 can be excavated by rotating the face plate 6b.

  As the excavator 6, either a shield excavator or a propulsion device can be applied. In the present embodiment, a case where a propulsion device is used will be described below.

  The excavation by the excavator 6 can be performed from an arbitrary position of the peripheral wall position of the underground structure 5. In FIG. 2, the leading element 7 is disposed near the center of the ceiling of the underground structure 5, and excavation is started from this position.

  Further, the leading end of the leading element pipe 7 is brought into contact with the rear end of the excavating machine 6, and the leading end of the leading element pipe 7 is pushed into the ground 1 by pushing the rear end of the leading element pipe 7 with a propulsion jack from the wellhead. Include.

  The leading element pipe 7 is added at the wellhead by the amount pushed by the propulsion jack, and further pushed into the ground 1.

  And after arrangement | positioning of the leading element pipe | tube 7 is completed, the digging machine 6 is propelled again along the groove part 70 of the leading element pipe | tube 7, as shown in FIG.

  Since the groove portion 70 is a hollow portion, the excavation hole 1a can be easily excavated by bringing the excavator 6 close to the leading element tube 7 side. However, a relative positional relationship is ensured to such an extent that the leading element tube 7 is not damaged by contact with the excavator 6.

  Furthermore, as shown in FIG. 5, the element pipe 9 is propelled into the excavation hole 1a (right side of the figure) excavated later. The element tube 9 is propelled so that the pair of engagement brackets 9f and 9f are engaged with the groove portion 70 of the leading element tube 7.

  The element tube 9 is propelled by bringing the tip of the element tube 9 into contact with the rear end of the excavator 6 and pushing it with a propulsion jack from the wellhead in the same manner as the leading element tube 7.

  Thus, since the engagement brackets 9f and 9f are inserted into the hollow groove portion 70, the engagement brackets 9f and 9f hardly become a propulsion resistance or an obstacle. Further, if the element tube 9 attempts to rotate relative to the leading element tube 7 during propulsion, the engagement brackets 9f and 9f come into contact with the side surface portions 7d and 7d to prevent the rotation. 9 is arranged at an accurate position without being separated from the leading element tube 7.

  The process up to this point is the element tube arranging step, and the water stop portion forming step will be described below.

  First, in order to remove the earth and sand clogged in the hollow portion of the guide member 8, a high-pressure washing tube is inserted into the guide member 8 to clean the inside of the guide member 8. Since this cleaning may be performed along the guide member 8, a continuous guide hole can be easily formed.

  Then, as shown in FIG. 6, the injection tube 8 b is inserted into the guide member 8. Side holes are provided at predetermined intervals on the side surface of the injection tube 8b, and the gap between the injection tube 8b and the guide member 8 can be filled with the ground improvement material 10a.

  The ground improvement material 10a filled in the guide member 8 is discharged to the underground 1 through the penetration portion 8a, and the underground 1 in contact with the boundary portion 7b between the outer shell 7a and the side surface portion 7d is altered and stopped. A water portion 10 is formed.

  By forming the water stop portion 10 in this way, it is possible to block the path of water entering the inside through the gap between the outer shell 9a and the boundary portion 7b.

  Further, by pulling out the injection tube 8b after the injection, the ground improvement material 10a that is not injected into the underground 1 is recovered, so that the injection loss can be reduced.

  FIG. 1 is a cross-sectional view of a state in which the underground portions 1 adjacent to both sides of the groove portion 70 are altered to form the water stop portions 10, 10.

  In this way, the underground pipe 5 is constructed by repeating the connection between the element pipes 7, 9,. In FIG. 2, the arrangement starts from the leading element tube 7, and an element tube 9 having a groove portion 90 formed on the right side is sequentially connected to the right side thereof, and an element having a groove portion 110 formed on the left side on the left side. The pipes 11 are sequentially connected to form a ceiling portion.

  Element tubes 12 and 12 having a groove 120 on the lower side and an engagement bracket 12f on the side in the coupling direction are arranged at the corners of the ceiling.

  Further, the element tubes 11 and 9 are arranged again at the lower end of the side wall portion of the underground structure 5, and the element tubes 11, 9,... Are arranged from both sides toward the center of the floor slab portion.

  Finally, a closed element tube 13 provided with two sets of engagement brackets 13f,... On both side surfaces is arranged at a position between the element tubes 11 and 9, and the underground 1 is connected to the element tubes 7 and 9 , 11, 12, 13,...

  Since the enclosed underground 1 is shielded from the external underground 1 by the peripheral wall constituted by the element pipes 7, 9, 11, 12, 13,..., It is possible to excavate safely and easily. Can do. It is also possible to build a tunnel inside this peripheral wall.

  And an inner peripheral wall can also be provided in the excavated underground space.

  According to the construction method of the element pipe 9 and the underground structure 5 using the element pipe 9 as described above, the other element arranged adjacent to the groove portion 90 formed in one element pipe 9 is used. The pair of engaging brackets 9f and 9f of the tube 9 are engaged.

  For this reason, the element tube 9 can be disposed close to and at an accurate position without rolling. Moreover, since it can connect only by engaging surfaces, the restriction | limiting of a connection direction is loose, and it can respond easily also to the construction and construction error of a curved part.

  Further, since the element tube 9 is not forcedly inserted, excessive stress is generated in the constituent members of the element tube 9 such as the side surface portion 9d and the engagement bracket 9f at the time of installation, and the propulsion is impossible. There is nothing to do.

  And the looseness in the ground can be suppressed to a minimum by pushing in the element tube 9 having the outer shell 9a shape that is in close contact with the inner peripheral surface of the excavation hole 1a.

  Further, since the guide member 8 for injecting the ground improvement material 10a is previously extended to the outer shell 9a, the ground improvement material 10a can be easily injected, and can be quickly stopped outside the element tube 9. The water part 10 can be formed.

  Moreover, since the ground improvement material 10a should just discharge | emit it through the penetration part 8a, it can be easily inject | poured into the underground 1 in which the water stop part 10 is formed.

  For this reason, the water stop part 10 can be formed in the connection part of element pipes 9 and 9, and water can be stopped reliably. Moreover, the underground structure 5 can be safely constructed | assembled also in the underground 1 with a large earth pressure and water pressure, such as a deep underground, by improving the water stoppage of a connection part.

  Hereinafter, Example 1 of the above-described embodiment will be described. The description of the same or equivalent parts as those described in the above embodiment will be given the same reference numerals.

  In the said embodiment, although the ground improvement material 10a was used as a water stop part formation material, in Example 1, refrigerant | coolants, such as an antifreeze liquid used with a freezing construction method, are used as a water stop part formation material.

  There are refrigerants that are directly injected into the ground 1 and those that are circulated in the injection pipe to indirectly cool the underground 1, but in the case of direct injection, the same configuration as in the above embodiment is used. Since this can be done, a configuration that uses what circulates in the injection tube will be described.

  In the first embodiment, it is not necessary to provide the through portion 8a in the outer shell 9a, but the cooling efficiency can be improved by increasing the contact area between the guide member 8 and the inner surface of the outer shell 9a.

  For example, an injection pipe whose tip is folded back into a U-shape is inserted into the guide member 8, and the refrigerant cooled by a refrigerator installed at the wellhead is circulated inside the injection pipe. By doing so, the low temperature portion spreads in the order of the guide member 8, the outer shell 9 a, and the underground 1, and the underground 1 near the groove portion 90 is frozen to form the water stop portion 10.

  Since the water stop performance of the water stop part 10 formed by the freezing method is very high, the water stop of the connecting part between the element pipes 9 and 9 can be reliably performed.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Hereinafter, Example 2 of the above-described embodiment will be described. The description of the same or equivalent parts as those described in the embodiment and Example 1 will be given with the same reference numerals.

  In the second embodiment, a case where rectangular elements 14 and 15 having a substantially rectangular shape in cross section as shown in FIG. 7 are used will be described.

  The rectangular elements 14 and 15 are different from the above-described embodiment and Example 1 in that the outer shells 14a and 15a are formed of flat plates, but the other configurations are substantially the same. When the rectangular elements 14 and 15 are used, it is preferable to use a rectangular excavator having the same shape as the excavator 6.

  In the groove portions 140 and 150 of the second embodiment, the side surface portions 14d and 15d are connected to the side boundary portions 14b and 15b that are suspended or erected from the outer shells 14a and 15a that form the upper surface or the bottom surface of the rectangular elements 14 and 15, respectively. It is formed by installing.

  For this reason, when the rectangular element tubes 14 and 15 are connected, the boundary portion 14b does not contact the adjacent outer shell 15a and directly contact the ground 1. Therefore, the guide member 8 extended to the rectangular element pipes 14 and 15 has the outer shell 14a in contact with the ground 1 in the inner space surrounded by the groove portions 140 and 150, the outer shells 14a and 15a, and the bottom surface portions 14c and 15c. , 15a.

  By disposing the guide member 8 at such a position, the water stop portions 10 and 10 can be reliably formed at the connecting portions of the rectangular element tubes 14 and 15.

  Further, as shown in the rectangular example in the second embodiment, the cross-sectional shape of the element tube is not limited to a circular shape, and can be formed in various shapes such as a horseshoe shape and a square shape.

  Other configurations and functions and effects are substantially the same as those in the above-described embodiment, and thus description thereof is omitted.

  Hereinafter, Example 3 of the above-described embodiment will be described. The description of the same or equivalent parts as those described in the embodiment, Example 1 and Example 2 will be given with the same reference numerals.

  In the third embodiment, a case where a hollow portion for injecting the water stop portion forming material is formed in the inner space of the engagement bracket 9f will be described.

  As shown in FIG. 8, a substantially triangular prism-shaped hollow portion is formed by fixing a flat guide member 8B by welding or the like in the substantially triangular prism-shaped inner space of the engagement bracket 9f. The engaging bracket 9f facing the side surface portion 7d is formed with a penetrating portion 8c that communicates the side surface portion 7d side with the hollow portion.

  In addition, in the inner space of the element tube 7 surrounded by the outer shell 7a, the side surface portion 7d, and the bottom surface portion 7c extending outward from the side surface portion 7d, a guide having a substantially circular cross section is provided as in the above embodiment. The member 8A is extended along the longitudinal direction.

  In the third embodiment, the water stop portion is inserted on the outer surface side of the element tubes 9 and 7 by inserting the injection tube 8b into the guide member 8A and injecting the ground improvement material 10a into the underground 1 side through the penetration portion 8a. 10A is formed.

Then, the injection tube 8d is inserted into the hollow portion formed by the guide member 8B, and the solidified material 10b as the water stop portion forming material is inserted between the side surface portion 7d and the engagement bracket 9f through the penetration portion 8c. by injecting, forming a water stopper 10B around the engagement bracket 9f.

  Thus, the water stop of the connection part of element pipes 7 and 9 can be improved by making water stop parts 10A and 10B into a double structure.

  Further, depending on the performance of the water stop portion 10B, the guide member 8B and the injection pipe 8d may be disposed only on the engagement bracket 9f side to form only the water stop portion 10B.

  Furthermore, when the size of the inner space of the engagement bracket 9f is a size suitable for the hollow portion for injecting the water stop portion forming material, the guide member can be omitted.

  Other configurations and functions and effects are substantially the same as those of the above-described embodiment, Example 1, and Example 2, and thus description thereof is omitted.

  Although the best embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes that do not depart from the gist of the present invention are possible. Are included in the present invention.

  For example, in the above-described embodiment, the underground structure 5 having a substantially rectangular cross section as illustrated in FIG. 2 has been described. However, the present invention is not limited to this shape. For example, the cross section is circular, elliptical, or horseshoe-shaped. The underground structure 5 such as may be used.

  Further, the cross-sectional shape of the guide member 8 is not limited to a circular shape, and a hollow portion is formed by attaching the open side of a member having a substantially L-shaped cross section or a substantially U-shaped cross section to the inner side surface of the element tube 9. You can also.

  And, like the flat guide member 8B shown in the third embodiment, both side ends of the flat plate are fixed to the inner side surface of the outer shell 9a (7a) and the inner side surface of the side surface portion 9d (7d) by welding. A hollow part can also be formed.

  Furthermore, in the second embodiment, the cylindrical guide member 8 is extended, but instead of this, a flat guide member can be used to form a substantially triangular prism-shaped hollow portion. .

  In addition, the step of forming the water stop portion may be performed collectively after an arbitrary number of element tubes 9,... Are arranged, without being performed continuously immediately after the element tubes 9 are arranged.

  In the comb-shaped gap between the groove portions 70, 90,... Of the element tubes 7, 9,. In order to prevent this, the filler 3 having a strength capable of propelling the engagement brackets 9f and 9f can be filled.

  Furthermore, it can also be connected by engaging the groove part 90 of the element pipe | tube 9 arrange | positioned later with a pair of engagement bracket 9f, 9f of the element pipe | tube 9 arrange | positioned ahead.

  Moreover, the cross-sectional shape of the groove part 90 may not be a rectangle, but may be a trapezoid or a reverse trapezoid. In this case, the opposing engagement brackets 9f and 9f are also formed in accordance with the inclination of the side surface portions 9d and 9d.

It is sectional drawing explaining the structure of the connection part of the element pipe | tube of the best embodiment of this invention. It is sectional drawing of the underground structure constructed | assembled by the best embodiment of this invention. It is the partially cut perspective view which showed the state which connects and pushes an element pipe to the back of an excavation machine. It is sectional drawing explaining the state which excavates the excavation hole adjacent to the element pipe | tube arrange | positioned ahead. It is sectional drawing explaining the state which has arrange | positioned the succeeding element pipe | tube adjacent to the element pipe | tube arrange | positioned ahead. It is a partially expanded sectional view explaining the state in which a ground improvement material is inject | poured. It is sectional drawing explaining the structure of the connection part of the rectangular element tubes of Example 2. FIG. It is a partially expanded sectional view explaining the case where the hollow part for inject | pouring the water stop part forming material was formed also in the engagement bracket side of Example 3. FIG. It is sectional drawing of the underground structure built by connecting the steel elements of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Underground 1a Excavation hole 5 Underground structure 6 Excavator 8 Guide member 8a Penetration part 8b Injection pipe 9 Element pipe 90 Groove part 9a Outer shell 9f Engagement bracket 10 Water stop part 10a Ground improvement material (water stop part formation material)
11, 12 Element tube 15 Rectangular element tube (element tube)

Claims (3)

When forming a peripheral wall in the ground, the cylindrical element tube is arranged for each excavation hole by the excavator along the position of the peripheral wall and connects adjacent ones to each other to form the peripheral wall of the annular body. And
The cylindrical body is inscribed in the excavation hole and has a concave cross-sectional groove that opens outward on the first side surface, and a pair of engagement brackets project outward on the second side surface at an interval substantially equal to the width of the groove portion. Formed ,
A hollow portion for injecting a water stop portion forming material is extended in the longitudinal direction of the cylindrical body along the outer shell in an inner space sandwiched between the outer shell forming the cylindrical body and the groove portion. Characteristic element tube. 2. The element pipe according to claim 1 , wherein the outer shell communicating with the hollow portion is formed with a through portion through which a ground improvement material serving as the water stop portion injection material injected therein passes. . A method of constructing an underground structure that forms the peripheral wall using a plurality of element pipes according to claim 1 or 2 ,
An excavator is excavated in the ground at an arbitrary position corresponding to the peripheral wall position, the element pipe is arranged by being pushed into the excavation hole, and an excavator is provided along the groove portion of the element pipe arranged in advance. An element tube arrangement is formed by digging again to form a digging hole adjacent to the preceding element pipe, and by pushing into the digging hole while engaging the engagement bracket of the other element pipe with the groove portion. A water stop portion forming step of forming a water stop portion by inserting an injection tube into the hollow portion and altering the underground adjacent to the groove portion by the water stop portion forming material injected into the injection tube. Have
A construction method of an underground structure, wherein the element pipe is continuously arranged by repeatedly performing the element pipe arranging step and the water stop portion forming step sequentially or in parallel.

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