JP4759532B2 - Widening method of existing underground structure - Google Patents

Description

  The present invention relates to a method for widening an existing underground structure in which an existing underground structure such as an underground passage or the like crossing under a rail or a road is expanded in the width direction and reconstructed into an underground passage or the like having a large cross section.

  When expanding the width of an underground structure such as an existing underground passage that crosses under a rail or a road, the existing underground structure is conventionally made wider than the existing underground structure. A method of replacing the structure has been performed. For example, as described in Patent Document 1, a plurality of elongated plates are laid in parallel in the length direction of the existing underground structure on the upper surface of the upper floor of the existing underground structure, and the upper floor on both sides of the upper floor After placing a plurality of pipes on which elongated plates are placed in parallel at the same height position, the ends of all the elongated plates are fixed at a fixed location, and a rail is attached to the lower floor of the existing underground structure. Laying and placing a temporary carriage on this rail in a movable manner in the length direction of the existing underground structure to support the upper floor separated from both side walls of the existing underground structure, and then this existing underground structure By replacing the existing underground structure with the ready-made structure by propelling the ready-made structure by following the upper end front end face of the ready-made structure in abutting manner from the rear end face of the pipe row to the rear end face of the pipe row, Is going.

At this time, prior to the promotion of the ready-made structure, by pushing the ready-made structure while removing both side walls of the existing underground structure and the lower floor from the ready-made structure side by appropriate means such as destruction, The temporary floor cart that supports the upper floor of the existing underground structure is pushed forward on the rail laid on the lower floor, and the upper floor is pushed to the arrival side.
Japanese Patent Publication No. 06-105025

  As described above, when replacing existing underground structures with ready-made structures under rails or roads such as railways, they are ready-made in the direction crossing directly under the road or railway. Since the structure is to be propelled, it is not allowed for safety that the ground surface such as a rail or a road sinks when the upper floor of the existing underground structure is pushed toward the arrival side.

  For this reason, in the conventional method, a rail is laid on the lower floor of the existing underground structure, and the upper floor is supported at a certain height position by a temporary carriage that moves forward on the rail. If there is a slight height difference on the upper surface, the upper floor may move up and down during propulsion and the ground surface may fluctuate, and the length direction of the rail and the propulsion direction of the ready-made structure that pushes the upper floor may differ. If they do not match exactly, the upper floor will move in the horizontal direction on the temporary carriage and a sliding frictional force will be generated between the temporary carriage and the upper floor. Since force is required, there is a problem that not only the rail must be laid in advance in advance, but also the moving state of the upper floor must be managed during propulsion. Furthermore, such a problem is more likely to occur when the surface of the lower floor is uneven, and the difficulty in laying the rail with high accuracy increases.

  Further, prior to the promotion of the ready-made structure, the ready-made structure is promoted while removing both side walls of the existing underground structure and the lower floor from the ready-made structure side by an appropriate means such as destruction. Therefore, before propelling this ready-made structure for a certain length, the existing underground structure must be destroyed and removed by a predetermined length from the both side walls to the lower floor. Therefore, there is a problem that the work efficiency of replacing the existing underground structure with the ready-made structure is lowered.

  The present invention has been made in view of such problems. The purpose of the present invention is to replace an existing underground structure with an existing horizontal box having a width wider than that of the existing underground structure. The present invention provides a widening method for an existing underground structure that can smoothly and surely replace an existing underground structure and an existing horizontally long box while pushing the upper floor slab up and down accurately in a horizontal direction. .

In order to achieve the above object, the method for widening an existing underground structure according to the present invention is the method for widening an existing underground structure comprising an upper floor board and both side walls built in the ground as described in claim 1. And a plurality of elongated plates are laid in parallel in the length direction of the existing underground structure on the upper surface of the upper floor slab of the existing underground structure and at the same height position as the upper floor slab on the side of the upper floor slab. A step of forming a parallel pipe by placing a plurality of pipes on which elongated plates are placed in a parallel state, and a lower floor between the lower ends of both side walls of the existing underground structure before and after or in parallel with this step An existing underground structure in which a plate is slidably provided in the length direction of the existing underground structure, and a temporary receiver is provided between the lower floor plate and the upper floor plate, and the upper floor plate is supported by the temporary receiver. A process of separating the upper floor slab of the object and both side walls, and the existing underground structure And subsequent to cause a wide shelf horizontally a box body than underground construction with joining the front end of the top floor of the ready-made oblong box-body shape butt to the rear end of the rear end and the parallel pipe top floor version of the existing underground structures A step of joining the front end of the lower floor portion of the ready-made horizontal box to the rear end of the lower floor slab, and after this step, by appropriate means such as breaking both side walls of the existing underground structure from the rear end side With the length removed as appropriate, the upper floor slab of the existing underground structure is supported by the temporary support body with the lower surface of the parallel elongated plate fixed to the immovable location according to the removal length of both side walls as a guide surface. It is characterized by comprising a step of replacing the existing underground structure and the ready-made horizontal box by propelling the ready-made horizontal box and the parallel pipe by propelling integrally with the lower floor slab.

  In the widening method of the existing underground structure configured as described above, the invention according to claim 2 includes the installation portion of the lower floor slab before the lower floor slab is installed between the lower ends of both side walls of the existing underground structure. A sliding surface material is laid below the sliding surface material, and a lower floor slab is slidably mounted on the sliding surface material, and the invention according to claim 3 comprises a plurality of rectangular pipes. The lower floor slab is formed by installing in parallel on the sliding face material.

  On the other hand, in the invention according to claim 4, when the existing underground structure has a lower floor slab integrally provided between the lower end portions of both side walls, a sliding surface material is laid on the lower surface of the lower floor slab. After that, the lower floor slab is provided so as to be slidable on the sliding face material by separating it from both side walls.

According to the method for widening an existing structure of the present invention, a lower floor slab is provided slidably in the length direction of the existing underground structure between the lower ends of both side walls of the existing underground structure built in the ground. After that, a temporary receiver is provided between the upper floor slabs of the existing lower floor slab and the upper floor slab is supported by the temporary receiver to separate the upper floor slab from the both side walls. Install an elongated plate following an existing underground structure, which is wider than the existing underground structure, and remove both side walls of the existing underground structure from the rear end by appropriate length by breaking or the like. The existing underground structure is constructed by propelling the upper floor slab of the underground structure integrally with the lower floor slab and propelling the prefabricated horizontal box and the parallel pipes placed on the side of the upper floor slab of the existing underground structure. And the ready-made horizontal box, the temporary holder is on the lower floor plate. Since the upper floor slab can be moved forward integrally with the upper and lower floor slabs without moving, the upper floor slab can be pushed to the lower floor slab while being held at a constant height by the temporary support body. Smoothly and reliably replace the existing underground structure with a wide, pre-existing horizontal box while preventing the ground surface such as rails and roads above the plate from sinking or changing. Widening can be performed.

  Furthermore, prior to the promotion of the ready-made horizontal box, the rear ends of both side walls of the existing underground structure are destroyed and removed from the pre-made horizontal box side by a predetermined length, but the lower floor slab is not destroyed, Since it is pushed out to the arrival side integrally with the upper floor slab and destroyed and removed on the arrival side, the rear ends of both side walls of the existing underground structure are destroyed and removed by a predetermined length, and then immediately by the promotion of the ready-made horizontal box The replacement work of the existing underground structure can be performed, and the widening work of the existing underground structure can be performed efficiently.

  Further, according to the invention of claim 2, before installing the lower floor slab between the lower ends of both side walls of the existing underground structure, a sliding surface material is laid below the installation part of the lower floor slab. In addition, since the lower floor slab is slidably mounted on the sliding surface material in the front-rear direction, the sliding surface material should be easily laid so that its upper surface is parallel to the lower surface of the upper floor slab. Since the lower floor slab is moved forward on the sliding surface material, the lower floor slab is held on the upper floor while holding the upper floor slab at a fixed height position via a temporary support placed on the lower floor slab. The sliding face material can be smoothly slid and moved toward the arrival side integrally with the plate.

  According to the invention according to claim 3, the lower floor slab is formed by installing a plurality of rectangular pipes in parallel on the sliding surface material, so that the lower floor slab is easily formed. In addition, it is possible to form the lower floor slab with a certain thickness that can firmly support the upper floor slab via the temporary support.

  On the other hand, according to the fourth aspect of the present invention, an existing underground structure having a rectangular cross section in which an upper floor slab and a lower floor slab are integrally provided between the upper end portions and the lower end portions of both side walls is provided with a prefabricated oblong box. This is a method of widening by replacing the body with a sliding surface material on the lower surface of the lower floor slab of the existing underground structure, and then separating the lower floor slab from both side walls to Because it is a slidable lower floor slab, a temporary receiving body was installed on this lower floor slab without installing a new lower floor slab, and separated from both side walls of the existing underground structure. The upper floor slab can be supported by the temporary support body. In this state, the rear base of both sides of the existing underground structure is destroyed and removed by a predetermined length, and the existing underground structure is promoted. The upper floor slab is converted into the lower floor slab by performing the following and the subsequent promotion of the ready-made horizontal box integrally or separately. Constantly pushed while holding at a constant height position, the widening operation by replacement of the existing underground structures and the existing underground construction can be performed with good efficiency by by provisionally receptacle against.

  A specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an existing underground structure 1 having the same height as the existing underground structure 1 and a wider width than the existing underground structure 1. FIG. 2 is a simplified longitudinal side view of a state in which the existing underground structure 1 is widened by replacing it with an existing horizontal box 2 made of an RC contact structure, and FIG. 2 is an enlarged longitudinal front view of the existing underground structure. The object 1 is composed of an upper floor slab 1a having a constant width and thickness over the entire length, and both side walls 1b and 1b having a constant height and having upper end surfaces integrally connected to the lower surfaces of both side ends of the upper floor slab 1a. It is a concrete structure with a cross-sectional gate shape, and is constructed in the ground below this rail 3 so as to cross this existing underground structure 1 under the rail or under the passage (hereinafter referred to as rail 3). Open both ends of the longitudinal direction on both sides of the rail 3 To have.

  In order to widen the existing underground structure 1 by replacing it with the above-mentioned prefabricated horizontal box 2, the side where the prefabricated horizontal box 2 follows the existing basement structure 1 is set as the start side 4, and the existing subsurface structure 1 is With the extrusion side as the arrival side 5, first, a plurality of steel plate strips 6, 6, 6... 6 are in contact with each other at both end surfaces in the length direction on the upper surface of the upper floor slab 1a of the existing underground structure 1. In parallel, lay in parallel. The long plate 6 is laid by excavating the ground below the rail 3 to expose the upper floor slab 1a of the existing underground structure 1 and placing it on the upper floor slab 1a, and then refilling the ground. Alternatively, the elongated plate 6 may be press-fitted on the upper floor slab 1a of the existing underground structure 1 with the ground as it is so as to penetrate from the starting side 4 toward the reaching side 5, or from the reaching side 5 with a wire or the like. It may be performed by towing.

  Further, a plurality of cross-sections in which an elongated plate 6 of the same size and shape as the elongated plate 6 is placed on the upper surface at the same height as the upper floor plate 1a on both sides of the upper floor plate 1a of the existing underground structure 1. A rectangular steel pipe 7 is driven in parallel to form a parallel pipe that is continuous in the lateral direction, and a plurality of pipes of the same size and the same shape as the pipe 7 downward from both side ends of the parallel pipe. The steel pipes 7 are sequentially placed in parallel in the vertical direction with the elongated plates 6 placed on the pipes 7 facing outward to form parallel pipes stacked in a line. The front end of the elongated plate 6 is detachably fixed to the tip of the pipe 7, and in order to drive each pipe 7 into the ground, an auger (not shown) is inserted into the pipe 7 to excavate the front ground. However, it is performed by propelling from the start side 4 toward the arrival side 5. The existing underground structure 1 is placed so that the width between the outermost pipes 7 and 7 in the pipe row arranged in parallel on both sides of the upper floor slab 1a is equal to the width of the ready-made horizontal box 2 to be replaced. Yes.

  The front ends of these parallel pipes and the front ends of the elongated plates 6 laid on the upper surface of the upper floor slab 1a are projected to the arrival side 5, and the front ends of all the elongated plates 6 on the parallel pipes are separated from the pipes 7. After that, the front ends of all of the elongated plates 6 aligned in a row and the front ends of all of the elongated plates 6 aligned in the vertical direction are in close contact with and supported by the side surface of the ground from which these elongated plates 6 protrude. On the starting side 4, all the elongated plates 6 projecting rearward are made of H-shaped steel or the like arranged orthogonally on these elongated plates 6, while being fixed integrally to the fixing frame 12 being welded. The connecting member 13 is integrally connected to all the elongated plates 6 by being fixed by welding or the like. The work of separating the front end of the elongated plate 6 from the pipe 7 and the work of fixing the end may be performed at any time before the replacement of the existing underground structure 1 and the ready-made horizontal box 2 is started.

  In addition, a lower floor slab 11 is slidably laid in the length direction of the existing underground structure 1 on the floor surface between the lower ends of both side walls 1b and 1b of the existing underground structure 1. At this time, in order to allow the sliding movement of the lower floor slab 11 to be smooth and accurately slid without fluctuation in the vertical direction, the upper surface is formed on a smooth surface below the installation portion of the lower floor slab 11 The sliding surface material 9 having a certain thickness is laid and fixed over substantially the entire width of the lower floor slab 11, and the lower floor slab 11 is laid on the sliding surface material 9 so as to be slidable in the length direction. ing. As shown in FIG. 1, the sliding surface material 9 is continuously laid and fixed in a horizontal plane up to the ground surface on the starting side 4.

  As the lower floor slab 11, a steel plate having a shape that is formed in a horizontally long rectangular frame shape having a certain thickness with a steel plate may be used. However, as shown in FIG. A plurality of pipes 11a are installed in parallel on the sliding face material 9, and these pipes 11a, 11a are sequentially connected to each other to form a smooth surface with a constant height. The lower floor slab 11 is configured. As with the pipe 7, the auger (not shown) is inserted into the pipe 11a, and the pipe 11a is propelled from the start side 4 toward the arrival side 5 while excavating the front ground. Done.

  After laying the lower floor slab 11 between the lower ends of the existing underground structure 1, the temporary receiver 8 is installed on the lower floor slab 11 and the upper floor slab 1 a is supported by the temporary receiver 8. The upper floor slab 1a of the underground structure 1 is separated from both side walls 1b and 1b. The temporary support 8 has a fixed base 8a that supports the lower base plate 8a1 on the upper surface of the lower floor slab 11, and a predetermined interval in the length direction and the width direction on the upper base plate 8a2 of the fixed base 8a. It consists of a plurality of jacks 8b erected and supported each time and a plurality of support girders 8c installed and fixed between the upper end surfaces of these jacks 8b, 8b. The upper surface of the upper floor slab is pressed against the lower surface of the upper floor slab 1a over the entire length so that the upper floor slab 1a is held at a height position before being separated from the side walls 1b and 1b. The upper floor slab 1a and the side walls 1b and 1b are separated by a wire saw (not shown).

  Further, the upper base plate 8a2 of the fixed base 8a is configured such that its width can be expanded and contracted by a jack 8d, and before supporting the upper floor slab 1a by the support beam 8c, both side end surfaces of the upper base plate 8a2 are Via a sliding material such as grease applied or affixed to the side end face, or via a roller attached to the side end face, slidably pressed against the inner side face of the both side walls 1b, 1b, both side walls 1b, 1b is prevented from tilting inward. A lower floor slab 11 is laid between the lower ends of the existing underground structure 1, and a temporary receiver 8 is provided between the lower floor slab 11 and the upper floor slab 1a. The temporary receiver 8 supports the upper floor slab 1a. The process of separating the upper floor slab 1a and both side walls 1b, 1b in the state of being in the state is that the plurality of elongated plates 6 are arranged in parallel in the length direction of the existing underground structure 1 on the upper surface of the upper floor slab 1a of the existing underground structure 1. It may be before or after the step of laying and placing a plurality of pipes 7 in which the elongated plates 6 are placed at the same height as the upper floor slab 1a on the side of the upper floor slab 1a. You may do it.

  In this way, after the upper floor slab 1a separated from the upper ends of the side walls 1b, 1b is supported by the temporary support 8, the existing underground structure 1 is placed on the starting side 4 behind the existing underground structure 1. A prefabricated horizontal box 2 having the same height and width wider than the existing underground structure 1 is installed and followed by the existing underground structure 1, and the front end surface of the upper floor 2a of the prefabricated horizontal box 2 is installed in the existing basement. The rear end surface of the structure 1 and the rear end surfaces of the parallel pipes 7, 7 juxtaposed on both sides from the rear end surface are joined in a butting manner and downward from the both side ends of the parallel pipes 7, 7. The front end surfaces of both side walls 2b, 2b of the ready-made horizontal box 2 are joined to the rear end faces of the pipes 7, 7 arranged in parallel in the vertical direction, and the lower floor part of the ready-made horizontal box 2 is further joined. The front end surface in the center in the width direction in 2c is joined to the rear end surface of the lower floor slab 11 in a butted manner. The

  Although the front end face of the ready-made horizontal box 2 may be directly brought into contact with the rear end face of the existing underground structure 1, in this embodiment, as shown in FIG. 2 is mounted on the front end face of the frame 2 with the same shape as the cross-sectional shape of the ready-made oblong box 2, and the upper floor slab 1a and the lower floor slab of the existing underground structure 1 are mounted on the front end face of the blade edge frame 14. A plurality of intermediate push jacks 15 for pressing the rear end face of 11 and the rear end faces of the parallel pipes 7 and 7 are mounted.

  On the other hand, a reaction force receiving wall member 10 is erected on the sliding surface member 9 on the rear side of the prefabricated horizontally long box 2 and fixed to the upper end of the reaction force receiving wall member 10 at the rear end of the elongated plate 6 row. The connecting member 13 is connected by a connecting member 16 such as an anchor, and a plurality of propulsion jacks 17 are attached to the front surface of the reaction force receiving wall member 10. A push frame 18 is interposed between the rear end surfaces. The reaction force receiving wall member 10 may be fixed on the sliding face member 9, or may be installed so as to be movable forward.

  After the ready-made horizontal box 2 and the reaction force receiving wall member 10 are arranged on the starting side 4 as described above, when the intermediate push jack 15 is extended, the upper floor slab 1a of the existing underground structure 1 and the parallel pipe 7, 7 is a fixed-length elongate plate 6 fixed in a stationary state by the fixing frame 12 and the connecting member 13 as a guide, and moves forward toward the arrival side 5 while sliding in contact with the rain on the opposite surface, and this existing underground structure. The lower floor slab 11 of 1 also slides on the sliding face material 9 and advances together with the upper floor slab 1a simultaneously by a certain length. At this time, the temporary support body 8 supporting the upper floor slab 1a also moves forward together with the upper and lower floor slabs 1a and 11 while holding the upper floor slab 1a at a certain height position.

  In this way, when the upper and lower floor slabs 1a and 11 of the existing underground structure 1 and the parallel pipes 7 and 7 are propelled to the arrival side 5 by a certain length, the rear ends of both side walls 1b and 1b of the existing underground structure 1 Will be exposed from the rear end of the upper and lower floor slabs 1a and 11 by the propulsion length of the upper and lower floor slabs 1a and 11, and the exposed rear ends of the side walls 1b and 1b are exposed from inside the prefabricated horizontal box 2 by a hammer or the like. Remove by appropriate means such as destruction. After that, by extending the propulsion jack 17 disposed on the starting side 4, the prefabricated oblong box 2 is used as a guide with the elongated plate 6 and the sliding face member 9 as a guide. Just promote. At this time, the intermediate push jack 15 is contracted according to the propulsion speed so that the propulsive force by the propulsion jack 17 is not transmitted to the existing underground structure 1 side.

  Next, the middle push jack 15 is extended again, so that the upper and lower floor slabs 1a, 11 of the existing underground structure 1 and the parallel pipes 7, 7 are integrally propelled to the arrival side 5 and then propelled. The rear part of the exposed existing underground structure 2 is destroyed and removed, and then the propulsion jack 17 is extended to propel the ready-made horizontal box 2 by the same length following the existing underground structure 1. By repeating the above, the existing underground structure 1 and the existing horizontal box 2 are replaced, and a passage made of the existing horizontal box 2 in which the existing underground structure 1 is widened under the rail is constructed.

  In this widening operation, the upper and lower floor slabs 1a, 11 and the pipe 7 of the existing underground structure 1 pushed out to the arrival side 5 are cut each time they protrude to the arrival side 5 by a certain length. The ground in front of both sides of the prefabricated horizontal box 2 projecting outward from the outer side surfaces of the both side walls 1b and 1b of the existing underground structure 1 is an appropriate excavator such as a shovel from the prefabricated horizontal box 2 Exclude and eliminate by. The ready-made horizontal box 2 is divided into several parts in the length direction, and the ready-made horizontal box 2 is sequentially replaced with the existing underground structure 1 while being connected to the existing underground structure 1. Also good.

  In addition, the existing underground structure 1 may be integrally propelled by the propulsive force of the ready-made horizontal box 2 without providing the intermediate push jack 15, and in this case, both side walls 1b and 1b of the existing underground structure 1 are After that, the work to remove from the end side by appropriate length, destruction, etc. is performed in advance. After this work, the existing underground structure 1 is integrated with the prefabricated horizontal box 2 for the length of the broken side walls 1b, 1b. In any case, after the existing horizontally long box 2 follows the existing underground structure 1, the both sides of the existing underground structure are appropriately lengthened by appropriate means such as destruction from the rear end side. In accordance with the removal length of the side walls and the lower surface of the parallel elongated plate, the upper floor slab of the existing underground structure is supported by the temporary support body in accordance with the removal length of the side walls, and integrally with the lower floor slab. And propulsion of ready-made horizontal box and the above parallel pipe It goes and replaces the existing underground structure 1 and the existing horizontally long box 2.

  Fig. 3 shows an existing underground structure 1 'built under the rail 3 from a concrete structure having a rectangular cross section in which an upper floor slab 1a, side walls 1b, 1b and a lower floor slab 1c are integrally provided. Thus, this existing underground structure 1 ′ has the same height as the existing underground structure 1 ′ and has a horizontal width that is wider than the existing underground structure 1 ′. It is a longitudinal sectional front view for explaining a method of widening by substituting with, and when widening by replacing this existing underground structure 1 'with the above-mentioned prefabricated horizontal box 2, existing underground structure 1' A plurality of steel strips 6, 6, 6... 6 are laid on the upper surface of the upper floor slab 1a, or the same height as the upper floor slab 1a on both sides of the upper floor slab 1a of the existing underground structure 1 ′. In this position, a plurality of steel pipes 7 having a rectangular cross section with an elongated plate 6 placed on the upper surface are arranged side by side. In addition, the pipes 7 are sequentially placed in parallel in the vertical direction with the elongated plates 6 facing outward from the opposite ends of the parallel pipes, and the ends of all the elongated plates 6 are Since the part is fixed to a stationary part and the propulsion means such as the propulsion jack 17 is arranged on the start side, the same parts are denoted by the same reference numerals and detailed description is omitted. To do.

Configuration different from the above embodiment, the lower deck 1c in the existing underground structures 1 'is a point which is provided integrally embedding the sliding surface member 9 in contact with the lower surface of the lower deck 1c In addition, the temporary receiver 8 having the same structure as described in the above embodiment is installed on the lower floor slab 1c, and the upper floor slab 1a is supported on both sides of the upper floor slab 1a with the temporary receiver 8 supporting the upper floor slab 1a. The walls 1b and 1b are separated from each other by a wire saw, and the lower floor slab 1c is separated from the lower ends of both side walls 1b and 1b by a wire saw, so that the lower floor slab 1c together with the upper floor slab 1a is the length of the existing underground structure 1 '. Move in the vertical direction. In addition, the sliding face material 9 does not need to be newly buried when it is laid on the lower surface side of the lower floor slab 1c when the existing underground structure 1 ′ is constructed.

  In this way, after separating the lower floor slab 1c of the existing underground structure 1 'from the side walls 1b and 1b, the existing underground structure 1' is followed by the existing horizontally long box 2 'in the same manner as in the above embodiment. While removing both side walls 1b and 1b of the underground structure 1 'from the rear end by a fixed length portion, destruction, etc., each time the fixed length portions of both side walls 1b and 1b are removed, they slide with the elongated plate 6 The upper and lower floor slabs 1a and 1b of the existing underground structure 1 'are propelled together with the temporary support 8 for a fixed length using the face material 9 as a guide, and the parallel pipe 7 and the prefabricated horizontal box 2' are also driven with a fixed length. By doing so, the existing underground structure 1 'and the existing horizontally long box 2' are replaced.

  At this time, as described in the above embodiment, when the intermediate pushing jack 15 is interposed between the existing underground structure 1 ′ and the existing horizontally long box 2 ′, the upper and lower floors of the existing underground structure 1 ′. After the plates 1a and 1c are propelled for a certain length according to the removal length of the side walls 1b and 1b, the ready-made horizontal box 2 'is propelled for a certain length by the propulsion jack 17, but without the intermediate push jack 15 being provided. By connecting the ready-made horizontal box 2 'directly to the rear end of the existing underground structure 1' in a butted manner and propelling the ready-made horizontal box 2 'by the propulsion jack 17, the upper and lower floors of the existing underground structure 1' The plates 1a and 1c may be simultaneously propelled together with a fixed length, ready-made horizontal box 2 '. In this case, the parallel pipe 7 is also pushed to the arrival side 5 by the front end face of the ready-made horizontal box 2 'and pushed out.

The simplified vertical side view of the state which has expanded the existing underground structure. The enlarged vertical front view in the AA line. The simplified vertical side view of the state which has expanded the existing underground structure of another structure.

Explanation of symbols

1 Existing underground structure
1a Upper floor
1b Side wall 2 Ready-made horizontal box 3 Rail 4 Starting side 5 Arrival side 6 Elongated plate 7 Pipe 8 Temporary body 9 Sliding face material
11 Lower floor version

Claims (4)

A method of widening an existing underground structure composed of an upper floor board and both side walls built in the ground, wherein a plurality of elongated plates are arranged on the upper surface of the upper floor slab of the existing underground structure in the length direction of the existing underground structure forming a parallel pipe by Da設a plurality of pipes mounted with the elongated plate to the same height as the upper deck at the side of the upper deck in parallel state with laid in parallel, the Before and after or in parallel with the process, a lower floor slab is provided between the lower ends of both side walls of the existing underground structure so as to be slidable in the length direction of the existing underground structure, and between the lower floor slab and the upper floor slab. And a step of separating the upper floor slab and both side walls of the existing underground structure in a state where the upper floor slab is supported by the temporary receiver and the existing underground structure is wider than the existing underground structure. The front end of the upper floor of this prefabricated horizontal box is already installed by following the prefabricated oblong box A step of joining the front end of the lower floor of the該既made oblong box making body causes joined to form butt to the rear end of the rear end and the parallel pipe top floor plate of the lower structure to form abutting the rear end of the lower deck After the step, the side walls of the existing underground structure are appropriately removed from the rear end side by appropriate means such as destruction, and the parallel elongated plates fixed to the immovable portion according to the removal length of the both side walls. The existing floor box and the parallel pipe are propelled together with the lower floor slab while the upper floor slab of the existing underground structure is supported by the temporary support body with the lower surface as the guide surface. A method of widening an existing underground structure, comprising a step of replacing an underground structure with an existing horizontal box.   Before installing the lower floor slab between the lower ends of both side walls of the existing underground structure, a sliding surface material is laid below the lower floor slab installation part, and the lower floor slab is placed on this sliding surface material. The method of widening an existing underground structure according to claim 1, wherein the slidable is placed slidably.   The method for widening an existing underground structure according to claim 1 or 2, wherein the lower floor slab is formed by installing a plurality of rectangular pipes in parallel on a sliding face material. .   The existing underground structure consists of an upper floor slab, both side walls, and a lower floor slab. After laying a sliding surface material on the lower surface of this lower floor slab, the lower floor slab is separated from both side walls, thereby sliding the surface material. The method for widening an existing underground structure according to claim 1, wherein the method is provided so as to be slidable upward.

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