JP5102242B2 - Reach method of box structure - Google Patents

Description

  The present invention relates to a reaching method for a box structure, and in particular, a plurality of box-shaped roof pipes, in which box-shaped roof pipes having a plurality of rectangular cross sections are arranged side by side in the ground from the starting vertical shaft to the reaching vertical shaft, The present invention relates to a method for reaching a box structure in a box-type roof method in which the box structure is installed underground.

  For example, a box roof construction method is known as a construction method for building a box structure in the ground while maintaining the state of use of these railways and roads by crossing the railroad rails and roads below. (For example, refer to Patent Document 1). The box-shaped roof construction method is a method in which a plurality of box-shaped roof pipes having a rectangular cross section are arranged in a horizontal direction and a vertical direction along the outer peripheral shape of a box structure to be installed, preferably at a position corresponding to a ceiling part and a side wall part. The end face of the ready-made box structure is installed in the vertical roof with the end of the edge-cutting plate placed on the upper surface of the horizontal roof row fixed to the fixed position. The roof rows by the box-shaped roof pipes are brought into contact with the rows and the lateral roof rows and the box structures are advanced while excavating the ground inside the roof rows through the hollow interior of the box structures. The box structure is installed in the ground.

  In such a box roof construction method, the box roof pipe that is installed in the ground so that the unit box roof pipes are sequentially connected from the rear in the axial direction so as to dig from the starting shaft to the reaching shaft. It has become. In addition, the box-shaped roof pipe installed in advance in the ground is pushed out to the reaching shaft as the box structure advances, and the extruded box-shaped roof tube passes through the reaching shaft for each unit box-shaped roof tube. Will be removed. In addition, H-shaped steel, groove-shaped steel, etc. are assembled in the reach shaft, and a roof cradle is provided. Especially for box-type roof pipes installed on the ceiling, the unit box pushed out to the reach shaft The shape roof pipe is received by the roof cradle and then dismantled and removed.

Japanese Patent Publication No. 7-35719

  On the other hand, in the box-type roof construction method, the box body is advanced so that the box structure can be advanced efficiently while extruding the ground inside the roof row while extruding the box-shaped roof pipe installed in advance in the ground. A blade edge member is attached to the tip of the structure. For this reason, when the box structure reaches the reaching shaft, the blade member is pushed out to the reaching shaft, and the roof receiver provided in the reaching shaft is not disturbed by the pushed blade member. It may be necessary to remove a part of the gantry while maintaining the function of receiving the unit box-shaped roof pipe. Here, when the reaching shaft is formed with a considerable size and the roof cradle is supported and provided by a number of gantry support columns arranged in the pushing direction, interference with the blade edge member is prevented. Even if a part of the gantry support column is removed in order to avoid it, it is possible to stably receive the unit box-shaped roof pipe by the remaining roof cradle.

  However, due to land acquisition and surrounding traffic volume, it is not possible to form the reach shaft in a free size, and the length along the extrusion direction is longer than the length of the unit box roof pipe, for example. If the shaft can only be formed with a size shorter than twice the length of the box-shaped roof pipe, a large number of pedestal support pillars that support the roof cradle cannot be installed. Then, it becomes difficult to continue receiving the unit box-shaped roof pipe that has been pushed out in a stable state because the roof receiving table becomes unstable.

  The present invention was made in order to solve the technical problem peculiar to such a box roof construction method, and is attached to the tip of a box structure pushed out to the reaching shaft even when the reaching shaft cannot be formed large. An object of the present invention is to provide a method for reaching a box structure that can be received and removed in a stable state by a roof stand up to the last unit box-shaped roof pipe while avoiding interference with the blade edge member. .

  The present invention installs a box-shaped roof pipe having a plurality of rectangular cross-sections along the outer peripheral shape of the box structure to be installed side by side from the starting vertical shaft to the reaching vertical shaft. Later, the box structure in the box roof construction method is installed in the ground by excavating the box structure from the starting shaft to the reaching shaft by replacing the plurality of box-shaped roof pipes installed. It is a reaching method, and the reaching shaft is supported by installing a beam material between the reaching retaining wall and the opposing retaining wall, and is longer than the length of the unit box roof pipe, and the unit box roof It is formed with an interval shorter than twice the length of the pipe, and one end portion is supported by the opposing earth retaining wall at the reaching shaft, and between the reaching earth retaining wall and the opposite earth retaining wall. Standing up at a predetermined interval A roof cradle that is supported by a plurality of gantry support pillars and receives a unit box-shaped roof pipe arranged along the ceiling is provided, and when the box structure reaches the reach shaft, Along with advancement of the box structure, the unit box-shaped roof pipe of the ceiling part is pushed out and removed onto the roof cradle, and along with advancement of the blade member attached to the tip of the box structure The reach retaining wall, the roof cradle, the beam member, and the gantry support column in a portion overlapping with the blade member are sequentially removed, and at least 2 from the opposing retaining wall side at the latest. Until the pedestal support column arranged in the second position is removed, the gantry support column arranged closest to the opposed sediment wall is connected to the opposed soil retainer via a fixed stay member attached to the opposed sediment wall. Including supporting the wall As the gantry support pillar is removed from the reach retaining wall side, the remaining portion of the roof cradle, one end of which is supported by the opposing soil retaining wall, is moved through the fixed stay member. The object described above is achieved by providing a method for reaching the box structure that is supported by the gantry support column closest to the opposing retaining wall supported by the opposing retaining wall.

  And in the reach construction method of the box structure of the present invention, the portion of the roof cradle that is close to the opposing earth retaining wall until the second gantry supporting column is removed from the opposing earth retaining wall side at the latest. It is preferable to include a step of supporting the opposite retaining wall through the end reinforcing member attached to the opposite retaining wall.

  Moreover, it is preferable that the reach method of the box structure of the present invention includes a step of fixing the beam members and the gantry support columns to each other at an intermediate portion thereof.

  According to the reach method of the box structure in the box roof method of the present invention, even when the reach shaft cannot be formed large, avoid interference with the blade member attached to the tip of the box structure pushed out to the reach shaft. On the other hand, the last unit box-shaped roof pipe can be received and removed in a stable state by the roof cradle.

It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention. It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention. It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention. It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention. It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention. It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention. It is principal part sectional drawing explaining the operation | work process of the reaching method of the box structure which concerns on preferable one Embodiment of this invention.

  As shown in FIG. 1, a method for reaching a box structure according to a preferred embodiment of the present invention penetrates under a rail 20 of a railway, for example, to form an underground structure for a road tunnel, for example. Adopted when installing and constructing a hollow box structure 10 having a rectangular cross section by replacing it with a roof row of box-shaped roof pipes 11 installed in the ground below the railroad rail 20 in advance. It is a thing.

  Here, in the present embodiment, the box structure 10 has a blade edge member 12 attached to the tip portion thereof, and excavates the ground 21 inside the roof row while pressing the blade edge member 12 against the face surface. At the same time, the box-shaped roof pipe 11 is pushed toward the reaching shaft 13 while being pushed out to the reaching shaft 13. Moreover, in this embodiment, the box-shaped roof pipe 11 pushed out to the reaching shaft 13 is sequentially dismantled and removed from the unit box-shaped roof pipe 11a on the tip side in the pushing direction X as shown in FIGS. In addition, the unit box-shaped roof pipe 11a arranged along the ceiling portion 10a of the box structure 10 is received by the roof cradle 14 provided in the reaching shaft 13 and then disassembled and removed. It has become.

  Furthermore, in this embodiment, the reach shaft 13 is a unit box-shaped roof pipe 11a having a length along the pushing direction X of, for example, about 3.0 m in relation to land acquisition, surrounding traffic, and the like. Longer than the unit box-shaped roof pipe 11a and shorter than twice the length of the unit box-shaped roof pipe 11a, and when the box structure 10 reaches the reaching shaft 13, the blade edge member 12 is Since it is pushed out to the reach shaft 13 and interferes with the roof cradle 14 and the gantry support column 15 that supports it, it is necessary to remove the roof cradle 14 and the gantry support column 15 partly (FIG. 3). To FIG. 6).

  In the box-shaped roof construction method of the present embodiment, the box structure reaching method is such that even in such a narrow reaching shaft 13, the roof cradle 14 and the gantry support pillar 15 are partly removed, It is possible to receive the extruded unit box-shaped roof pipe 11a in a stable state while avoiding interference, and to dismantle and remove it, and to make the tip of the box structure 10 reach the arrival method 13 smoothly. It was adopted to do.

  And the reach method of the box structure of this embodiment is the box-shaped roof pipe 11 which has a some rectangular cross section along the outer periphery shape of the box structure 10 installed from the start vertical shaft to the arrival vertical shaft 13. By excavating towards the underground shaft by excavating the box structure 10, and then replacing the plurality of box-shaped roof pipes 11 installed, the box structure 10 is excavated from the starting vertical shaft toward the reaching vertical shaft 13. As shown in FIG. 1, the reaching shaft 13 is constructed by installing a beam member 18 between the reaching retaining wall 16 and the opposing retaining wall 17. It is formed by maintaining an interval longer than the length of the unit box-shaped roof tube 11a and shorter than twice the length of the unit box-shaped roof tube 11a. One end is opposite earth retaining 17, and supported by a plurality of gantry support pillars 15 erected and arranged at a predetermined interval between the reaching retaining wall 16 and the opposing retaining wall 17, to the ceiling portion 10 a of the box structure 10. A roof cradle 14 is provided for receiving the unit box-shaped roof tube 11 arranged along.

  Moreover, the reach | attraction method of the box structure of this embodiment is the unit box-type roof pipe 11 of a ceiling part with the advance of the box structure 10 when the box structure 10 is made to reach | attain the reach shaft 13. Is pushed onto the roof cradle 14 and removed (see FIGS. 2 and 3), and the portion of the portion overlapping the blade edge member 12 as the blade edge member 12 attached to the tip of the box structure 10 advances. The reach retaining wall 16, the roof cradle 14, the beam members 18 and the gantry support column 15 are sequentially removed (see FIGS. 3 to 6), and the second from the opposing retaining wall 17 side at the latest. Until the gantry support column 15b is removed, the gantry support column 15a arranged closest to the opposing retaining wall 17 is attached to the opposing retaining wall 17 via a stationary stay member 19 (see FIG. 5). And supporting the opposite retaining wall 17 As the gantry support column 15 is removed from the earth retaining wall 16 side, the remaining portion of the roof cradle 14 whose one end is supported by the opposing earth retaining wall 17 is connected to the opposing earth retaining wall via the fixed stay member 19. 17 is supported by a gantry support column 15a closest to the opposing retaining wall 17 (see FIG. 5).

  Furthermore, in the reaching method according to the present embodiment, the portion close to the opposing retaining wall 17 of the roof cradle 14 is not moved until the second supporting pillar 15b is removed from the opposing retaining wall 17 side at the latest. It includes a step of supporting the opposing earth retaining wall 17 via an end reinforcing member 22 (see FIG. 5) attached to the wall 17.

  In the present embodiment, as shown in FIG. 1, the reach shaft 13 is dug down to a side of the railroad rail 20 at a depth of, for example, about 10 m downward from the ground surface. Formed so as to have a rectangular planar shape having a length along the extrusion direction X of, for example, about 5.8 m and a length in the width direction perpendicular thereto being, for example, about 10 m, which is larger than the width of the box structure 10. Is done. The reach shaft 13 covers the inner wall surface of the excavation with the retaining walls 17 and 18 made of, for example, the main pile, and attaches the flank 23 made of H-shaped steel to an appropriate position of the retaining walls 17 and 18. By laying the cut beam material 18 made of, the earth pressure from the surroundings is supported and provided in a stable state. Further, in particular, the box-shaped roof pipe 11 extends in the pushing direction X between the reaching earth retaining wall 16 on the side through which the tip of the box structure 10 penetrates and the opposing earth retaining wall 17 opposed thereto. Thus, since the beam members 18 are installed in two upper and lower stages, the earth pressure applied to the ultimate earth retaining wall 16 and the opposing earth retaining wall 17 can be firmly supported.

  In addition, concrete is cast on the bottom of the reach shaft 13 to form a foundation bottom slab 24. The foundation slab 24 is formed vertically from a leg support 25 made of, for example, H-shaped steel laid on the foundation bottom slab 24. A plurality of gantry support columns 15 are provided to support the roof cradle 14 from below. The gantry support pillars 15 are made of, for example, H-shaped steel, and in this embodiment, two gantry support columns 15 are arranged at intervals in the extrusion direction X, and are arranged continuously in a direction perpendicular to the extrusion direction X to form two rows. Is provided. At the upper end portions of these gantry support columns 15, head connection platforms made of, for example, H-shaped steel, are provided so as to extend in a direction perpendicular to the extrusion direction X and connect the heads of the two rows of gantry support columns 15. 26 is attached, and the roof cradle 14 is assembled to the upper surface of the head connection base 26.

  The roof pedestal 14 is made of, for example, H-shaped steel, and is extended and arranged in the extrusion direction X, and a plurality of roof pedestals 14 are arranged in parallel in the direction perpendicular to the extrusion direction X. Each roof pedestal 14 is supported at the opposing retaining wall 17 by joining one end thereof to an end fixing member 27 made of, for example, H-shaped steel fixed to the opposing retaining wall 17, and at the other end and the intermediate portion. Is provided at a height position for receiving the unit box-shaped roof tube 11 disposed along the ceiling portion 10a of the box structure 10 by joining the upper surface of the head connection base 26 and supporting it on the gantry support column 15. Will be.

  And in this embodiment, it replaces with the roof row | line | column of the ceiling part and side wall part by the several box-shaped roof pipe | tube 11 previously installed in the ground according to the process substantially the same as each process of the conventional box roof construction method. Then, the box structure 10 is dug from the starting shaft toward the reaching shaft 13. Further, as the box structure 10 moves forward, the box-shaped roof tube 11 is pushed out to the reaching shaft 13 while the friction cut plate 28 is left in the ground, and the pushed-out box-shaped roof tube 11 is moved to the unit box-shaped roof. The tip portion of the box structure 10 is made to reach the reaching shaft 13 while being sequentially removed for each tube 11a. Further, the box-shaped roof pipe 11 disposed on the ceiling part receives the unit box-shaped roof pipe 11a pushed out to the reaching shaft 13 once by the roof support 14 and then the unit box-shaped roof pipe 11a at the front end side in the pushing direction. Will be dismantled sequentially. In the present embodiment, a roof propulsion jack box 29 is provided between the blade member 12 attached to the front end of the box structure 10 and the rear end of each box-shaped roof pipe 11. The box structure 10 and the box-shaped roof pipe 11 are pushed out in the extrusion direction X by the propulsion operation by the roof propulsion jack box 29 and a main push jack (not shown) provided in the start shaft. It has become.

  On the other hand, in the present embodiment, when the box structure 10 approaches the arrival shaft 13, unlike the conventional box roof construction method, for example, the arrival retaining wall 16 according to the following steps shown in FIGS. The box structure 10 is made to reach the reaching shaft 13 while removing the roof cradle 14, the beam member 18, and the gantry support column 15.

  That is, from the state shown in FIG. 1, the box structure 10 further approaches the reach shaft 13 as shown in FIG. 2, and as shown in FIG. 3, for example, the unit of the last part of the box-shaped roof pipe 11 at the ceiling When the front end of the box-shaped roof tube 11a moves forward to a position received by the roof cradle 14, the forward movement of the box structure 10 is temporarily stopped, and the second unit box-shaped roof tube 11a from the rearmost part is dismantled and removed. . Moreover, while removing the upper part of the reach | attainment retaining wall 16 located inside the roof row | line | column of the roof part of the ceiling part and side wall part by the box-shaped roof pipe | tube 11, and the upper flank 23 joined to this, and 2nd The upper beam 18 up to the gantry support column 15b is removed.

  Here, in this embodiment, prior to the work of removing the upper beam 18 up to the second frame support column 15b, as a reinforcing measure for preventing the roof frame 14 from falling, The material 18 and the gantry support column 15 can be fixed to each other at their intermediate portions. The step of fixing the beam member 18 and the gantry support column 15 is performed by welding or the like in a state where the beam member 18 is supported by a bracket attached to the gantry support column 15b, for example, at a position where they cross each other at an intermediate portion. Can be easily performed by bonding and fixing. The step of fixing the beam member 18 and the gantry support column 15 is preferably performed in the same step with respect to each joint portion between the pair of gantry support columns 15a and 15b and the upper and lower two-stage beam 18. Further, in addition to immediately before the upper beam 18 shown in FIG. 3 is removed, it can be fixed in advance in the steps shown in FIGS.

  When the upper part of the reach retaining wall 16 located inside the roof row by the box-shaped roof tube 11 is removed, the remaining reach retaining wall 16 located inside the roof row by the box-shaped roof tube 11 is removed as shown in FIG. After removing the lower bulge 23 and the lower beam 18 up to the second gantry support column 15b, the box structure 10 and the blade member 12 are further advanced. Let

  Here, by further advancing the box structure 10 and the blade edge member 12, the rear part of the second gantry support column 15 b and the roof cradle 14 in the push-out direction X are obstructive, so these are removed. There is a need. On the other hand, when the second gantry support column 15b is removed, the roof gantry 14 has one gantry support column 15a arranged on the most facing opposing retaining wall 17 side in the surface along the pushing direction X. It will be supported by the middle part only by it, and will be in an unstable state. Therefore, in this embodiment, until the gantry support pillar 15b arranged second from the opposing retaining wall side 17 is removed at the latest, as shown in FIG. 5, it is arranged closest to the opposing retaining wall 17 side. There is a step of supporting the gantry support column 15a on the opposing earth retaining wall 17 via a fixed stay member 19 attached to the opposing earth retaining wall 17.

  That is, in the step of supporting the opposing retaining wall 17 via the fixed stay member 19, for example, H-shaped steel is used as the fixed stay member 19, and preferably the flank 23 after removing the cut beam 18 is used as it is. For example, the flank 23 is firmly welded and joined to the opposing retaining wall 17, and one end portion of the fixed stay member 19 is flared and firmly fixed to the 23, and the other end portion of the fixed stay member 19 is supported by the gantry. By firmly welding and fixing to the column 15a, the gantry support column 15a is supported on the opposing earth retaining wall 17 via the fixed stay member 19 at two positions, upper and lower, in the middle portion of the gantry support column 15a.

  As a result, the gantry support pillars 15a are also supported from the opposing retaining wall 17 and are effectively prevented from overturning. Therefore, only one of the gantry support pillars 15a is disposed on the surface along each extrusion direction X. Also with the gantry support column 15a, the roof gantry 14 can be supported in a stable state from below.

  In the present embodiment, it is preferable that a portion of the roof pedestal 14 adjacent to the opposing soil retaining wall 17 is moved away from the opposing soil retaining wall 17 until the second base supporting column 15b is removed from the opposing soil retaining wall 17 side at the latest. It can also be supported on the opposing earth retaining wall 17 via an end reinforcing member 22 attached to the wall 17.

  That is, in the step of supporting the portion close to the opposing retaining wall 17 of the roof cradle 14 on the opposing retaining wall 17 via the end reinforcing member 30, for example, an H-shaped steel is preferably used as the end reinforcing member 30. For example, the bulge 23 after removing the beam 18 is used as it is, and, for example, the bulge 23 is firmly welded to the opposing retaining wall 17 and the lower end of the end reinforcing member 22 is bulged 23. And firmly fix the upper end of the end reinforcing member 30 to a portion of the roof pedestal 14 adjacent to the opposing retaining wall 17 to fix the roof pedestal 14 via the end reinforcing member 22. Is supported by the opposing earth retaining wall 17.

  This makes it possible to support the roof cradle 14 in a more stable state after the second cradle support column 15b is removed from the opposing retaining wall 17 side.

  Then, as described above, when the gantry support column 15a is supported on the opposing earth retaining wall 17 via the fixed stay member 19, the second gantry supporting column 15b is removed from the opposing earth retaining wall 17 side, and the box structure The article 10 and the blade member 12 are further advanced, and the rear portion 14a of the roof cradle 14 in the pushing direction X is removed.

  Further, as shown in FIG. 6, when the box structure 10 and the blade edge member 12 are advanced to a position where the last unit box-shaped roof tube 11a can be removed, the last unit box-shaped roof tube 11a is While removing via the reach shaft 13, the stand support pillar 15a arrange | positioned most at the opposing earth retaining wall 17 side, the remaining roof stand 14, the fixed stay member 19, the edge part reinforcement member 22, etc. are removed.

  When the gantry support pillar 15a and the remaining roof cradle 14 are removed, the box structure 10 and the blade member 12 are further advanced to reach the tip of the box structure 10 as shown in FIG. The shaft 13 is reached. When the tip of the box structure 10 is made to reach the reaching shaft 13, the blade member 12 is disassembled inside the reaching shaft 13, for example, and conveyed to the starting shaft via the box structure 10, thereby starting the vehicle. Collect from the shaft.

  Thus, according to the reach method of the box structure in the box roof method of the present embodiment, at the latest, until the gantry support column 15b arranged second from the opposing retaining wall 17 side is removed. In addition, since it includes a step of supporting the gantry support pillar 15a arranged on the most facing soil retaining wall 17 side to the facing soil retaining wall 17 via the intermediate fixed stay member 19, even when the reaching shaft 13 cannot be formed large, While avoiding interference with the blade edge member 12 attached to the tip of the box structure 10 pushed out to the reach shaft 13, the roof unit 14 receives and removes the unit box-shaped roof pipe 11a in a stable state. It becomes possible.

  The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, the gantry support pillars that are erected and arranged at a predetermined interval between the ultimate retaining wall and the opposing retaining wall are the pedestals that are disposed closest to the opposing retaining wall 17 in the plane along each extrusion direction X. It is not always necessary to arrange only two of the support pillars and the second support pillars arranged second, and three or more of each may be arranged. In addition, it is not always necessary to support a portion of the roof pedestal adjacent to the opposing retaining wall on the opposing retaining wall via the end reinforcing member.

DESCRIPTION OF SYMBOLS 10 Box structure 10a Ceiling part 11 of box structure Box-shaped roof pipe 11a Unit box-shaped roof pipe 12 Blade edge member 13 Reaching shaft 14 Roof receiving stand 15 Stand support pillar 15a Mount stand most opposed to the retaining wall side Support column 15b Standing support column 16 arranged second from the opposed retaining wall side Reaching retaining wall 17 Opposed retaining wall 18 Beam member 19 Rectangular pipe 20 constituting rail pipe 20 Rail rail 21 Rail ground inside roof 22 End reinforcement member 23 Raising ridge 26 Head connection base 27 End fixing material X Extrusion direction

Claims (3)

Along with the outer peripheral shape of the box structure to be installed, box-shaped roof pipes having a plurality of rectangular cross-sections are installed side by side by excavating from the starting shaft to the reaching shaft, and then installed. This is a box structure reaching method in the box roof method that is installed in the ground by excavating the box structure from the starting shaft to the reaching shaft by replacing with a plurality of box roof pipes. And
The reach shaft is supported by constructing a beam material between the reach retaining wall and the opposing retaining wall, and is longer than the unit box roof pipe and twice as long as the unit box roof pipe. It is formed with a shorter interval than that,
The reaching shaft is supported at one end by the opposing retaining wall and supported by a plurality of gantry support columns that are vertically arranged at a predetermined interval between the reaching retaining wall and the opposing retaining wall. A roof cradle is provided for receiving a unit box-shaped roof pipe arranged along the ceiling,
When the box structure reaches the reach shaft, as the box structure advances, the unit box roof pipe of the ceiling part is pushed out onto the roof cradle and removed,
As the blade member attached to the tip of the box structure advances, the reach retaining wall, the roof cradle, the beam member, and the gantry support column are sequentially removed at a portion overlapping the blade member. Is supposed to
In addition, at the latest, until the gantry support column arranged second from the opposing sedimentation wall side is removed, the gantry support column arranged closest to the opposing sedimentation wall side is attached to the opposing sedimentation wall. Including a step of supporting the opposing retaining wall through a fixed stay member,
As the gantry support pillar is removed from the reach retaining wall side, the remaining part of the roof cradle, one end of which is supported by the opposing soil retaining wall, is connected to the opposing soil retaining via the fixed stay member. A method for reaching the box structure that is supported by a gantry support column on the side of the opposite retaining wall supported by the wall. An end reinforcing member that attaches a portion of the roof pedestal adjacent to the opposing retaining wall until the second supporting pillar is removed from the opposing retaining wall side at the latest at the opposing retaining wall. The method for reaching the box structure according to claim 1, further comprising a step of supporting the opposing earth retaining wall through the box structure. The method for reaching a box structure according to claim 1, further comprising a step of fixing the beam members and the gantry support columns to each other at an intermediate portion thereof.

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