JP6265736B2 - Underground demolition method - Google Patents

Description

  The present invention relates to a demolition method for an existing underground structure.

  As a prior art, Patent Document 1 describes an underground demolition method that dismantles other pillars and beams while leaving the basement pillars and beams in a buttress shape so as to prevent the fall of the underground outer wall. Has been.

  Further, in Patent Document 2, a reinforcing wall is formed on an outer peripheral frame (column, beam, slab, etc.) of an existing underground structure, and the other existing underground structure is attached while leaving the outer peripheral frame and the reinforcing wall. The dismantling method to dismantle is described.

JP 2010-189960 A

JP 2011-163074 A

  In the dismantling method described in Patent Document 1, since the existing underground floor columns and beams are left as they are and used as a buttress to support the existing underground outer wall, the strength as the buttress may be insufficient.

  Further, in the dismantling method described in Patent Document 2, since the outer peripheral frame and the reinforcing wall at the position along the existing underground outer wall and the position adjacent to the reinforcing wall are left, the existing underground structure is disassembled. Since the outer peripheral frame or the like becomes an obstacle and the work space is narrowed in the basement, workability is poor and the construction period is long.

  An object of the present invention is to provide an underground demolition method capable of improving the workability of existing underground structure demolition while supporting the existing underground outer wall in consideration of the above facts.

In the underground demolition method according to claim 1 of the present invention, a retaining wall is temporarily installed in the construction surface of the existing underground frame orthogonal to the existing underground outer wall that remains as a retaining wall, and the existing underground outer wall is supported by the retaining wall. Then, the slab between the existing underground structures is removed, and the construction pillar of the new building is built while supporting the existing underground outer wall with the retaining wall .

  According to the underground demolition method with the above configuration, by installing a retaining wall in the construction surface of the existing underground frame, it is possible to provide the necessary strength against earth pressure, and the existing underground outer wall can be used as a retaining wall. it can. Moreover, since the slab between existing underground structures can be removed, a work space can be secured widely and workability is improved.

  The underground demolition method according to claim 2 of the present invention is the underground demolition method according to claim 1, wherein an auxiliary retaining wall is temporarily installed outside the surface of the existing underground structure that interferes with the true pillar of the new building. Then, the existing underground structure that interferes with the true pillar of the new building is removed.

  According to the underground demolition method with the above configuration, an auxiliary retaining wall will be temporarily installed outside the construction surface while allowing the prior construction of the construction pillars etc. of the new building by removing the existing underground structure that will obstruct pile driving. Thus, the existing underground outer wall with the required strength against earth pressure can be used as a retaining wall.

  The underground demolition method according to claim 3 of the present invention is the underground demolition method according to claim 2, wherein a reinforcing concrete is provided at a lower end portion of the auxiliary retaining wall temporarily installed outside the surface of the existing underground frame. To cast.

  According to the underground demolition method with the above-described configuration, the required strength against earth pressure acting via the existing underground outer wall can be obtained even if the auxiliary retaining wall is not surrounded by the existing underground frame.

  The underground demolition method according to claim 4 of the present invention is the underground demolition method according to claim 2 or claim 3, wherein the retaining wall and the auxiliary retaining wall are temporarily installed using a discarded formwork.

  According to the underground dismantling method with the above configuration, since the discarded formwork is used, the work of removing the retaining wall and the auxiliary retaining wall becomes unnecessary, and the workability is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the underground demolition construction method which can improve the workability of existing underground structure demolition can be provided, supporting the existing underground outer wall.

It is the whole sectional view showing the existing underground structure concerning the embodiment of the present invention. It is the perspective view which showed the state which constructed | assembled the retaining wall and the auxiliary retaining wall in the existing underground structure which concerns on embodiment of this invention. It is the perspective view which showed the prior dismantling completion state of the existing underground structure which concerns on embodiment of this invention. It is sectional drawing which showed the formwork of the retaining wall of the existing underground structure which concerns on embodiment of this invention, and an auxiliary retaining wall. (A)-(E) It is process drawing which showed the dismantling process of the existing underground structure which concerns on embodiment of this invention.

  An example of the dismantling method for the existing underground structure according to the embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, an existing underground structure M that is a target of the dismantling method according to the present embodiment is a four-floor structure, and includes RC columns, beams, and slabs. In this embodiment, the existing underground structure M is opened and dismantled while the existing underground outer wall 12 is left as a retaining wall, and the underground floor of the new building is constructed by the reverse driving method.

  In the process related to the demolition method of the existing underground structure M according to the present embodiment, as shown in FIG. 1, the underground fourth floor portion is backfilled by the dismantling gala G that is generated when the ground portion of the existing underground structure M is dismantled. . By refilling, the ground below the 3rd floor will be used as the ground for removing obstacles and building the structural pillar.

  Next, as shown in FIG. 2, in the existing frame 10 (existing pillar 10A and existing beam 10B) that does not interfere with the true pillar 40 of the new building, the underground outer walls 12 along the second and third basements The retaining wall 14 is constructed (temporary) in the construction surface of the frame 10 at the position. Further, the auxiliary retaining wall 18 is constructed at a position where the existing frame 16 interferes with the true pillar 40 of the newly-built building, etc., at a position (outside the structure) that avoids the interference location.

  Here, the construction method of the retaining wall 14 constructed in the frame of the frame 10 will be described.

As shown in FIG. 4, first, a plurality of holes are made in the existing column 10A and the existing beam 10B, the adhesive anchor 17 is inserted, and a reinforcing bar 22 (main reinforcing bar) is connected to the adhesive anchor 17 with a binding wire. To do. Further, the reinforcing bars 22A (distribution reinforcing bars) are arranged in a grid pattern with the reinforcing bars 22.

  Next, two lath mold units 30 comprising a metal mesh 26 (lass net) and a lattice-shaped mold 28 (lass mold frame) that supports the metal net 26 are suspended from a plurality of hooks 24 attached to the existing beam 10B. Lower. The two lath formwork units 30 are arranged so as to sandwich the reinforcing bars 22 in the construction surface of the frame 10, and are fixed to the angle 19 fixed to the existing beam 10B by welding. Further, the two lath mold units 30 are fixed with a separator 32 at a predetermined interval so as not to be deformed outward by the flow pressure of concrete.

  A plurality of openings for placing concrete (not shown) are formed in the existing beam 10 </ b> B, and the retaining wall 14 is constructed by placing concrete into the mold from these openings. Since the lath form unit 30 is a discarded form, it is not necessary to remove it from the concrete surface after the concrete placement is completed.

  When the auxiliary retaining wall 18 is constructed outside the frame 16, there is no existing column 10 </ b> A for fixing the lath mold unit 30, so a form panel is arranged on one side of the lath mold unit 30. Thereafter, concrete is cast into the mold from the opening of the lath mold unit 30 to construct the auxiliary retaining wall 18.

  Further, when the auxiliary retaining wall 18 is constructed outside the frame 16, as shown in FIG. 2, the anchor is taken from the slab 21 and is reinforced by the wrinkle concrete 34 provided on the lower surface of the slab 21. The wrinkle concrete 34 is straight and has a rectangular parallelepiped shape. The width of the upper surface is thicker than the width of the lower surface of the auxiliary retaining wall 18, and the length of the upper surface is the same as the length of the lower surface of the auxiliary retaining wall 18.

  Next, as shown in FIG. 3, the structures on the first basement floor to the third basement floor are dismantled and removed. At this time, all the slabs 20 from the first-floor slab 20A to the second-floor slab 20C are dismantled, leaving the underground outer wall 12, the retaining wall 14, the auxiliary retaining wall 18, and the frame 10 surrounding the retaining wall 14. Further, the frame 16 that interferes with the true pillar 40 of the new building is removed, and the through-hole 11 is formed in the slab 21 on the third basement floor. In addition, the depth of the third basement and below including the third basement slab 21 is the construction ground.

  In order to dismantle the slab 20 from the first-floor slab 20A to the second-floor slab 20C, leaving only the basement outer wall 12, the retaining wall 14, the auxiliary retaining wall 18, and the frame 10 surrounding the retaining wall 14, the existing underground When the structure M is dismantled and when a new building is pre-constructed, a work space can be widened on the basement floor, and workability is improved. In addition, since the retaining wall 14 and the auxiliary retaining wall 18 are temporarily installed, the required strength against earth pressure can be provided even if the slab 20 is removed.

  Here, the reverse placement method will be described with reference to FIGS. As shown in FIG. 5 (A), the structure of the basement floor is dismantled and removed while leaving the retaining wall 14, the auxiliary retaining wall 18, and the frame 10 surrounding the retaining wall 14, and then shown in FIG. 5 (B). As described above, the built-in column 40 of the new building is built by the cast-in-place pile method, and the first floor beam 43 and the first floor slab 42A are newly built on the built column 40. By supporting the existing retaining wall 50 with the first floor beam 43 and the first floor slab 42A, earth pressure applied to the underground outer wall 12 can be transferred to the first floor beam 43 and the first floor slab 42A of the new building.

  Next, as shown in FIG. 5C, the existing retaining wall 50 is left, and the temporary retaining wall 14, the auxiliary retaining wall 18, the underground outer wall 12, and the frame 10 surrounding the retaining wall 14 are dismantled. Remove. Since the slab 20 has been removed in advance, the work space can be widened, and the dismantling work can be performed efficiently.

Next, the underground outer wall 46 of the new building is constructed, and as shown in FIG. 5D, the first basement slab 42B and the second basement slab 42C are newly constructed.

  Next, as shown in FIG. 5 (E), the underground 3rd floor slab 21 of the existing underground structure M is dismantled and the dismantled galley G deeper than the 3rd floor underground is dug up. And the basement floor of a new building is constructed by newly constructing the basement third floor slab 42D and the basement fourth floor slab 42E of the new building.

  In the dismantling method of the existing underground structure M according to the embodiment of the present invention, the existing underground outer wall 12 is used as a retaining wall in order to reinforce the underground outer wall 12 by constructing the retaining wall 14 in the construction surface of the frame 10. When used, it can be provided with the necessary strength against earth pressure.

  In addition, in the place where the structure pillar 40 of the new building and the frame 16 of the existing underground structure M interfere with each other, the auxiliary retaining wall 18 is constructed outside the surface of the frame 16, so the structure 16 at the interfered part is dismantled in advance. Therefore, it is possible to perform the prior construction of the construction pillar 40 of the new building. Further, since the reinforcing concrete concrete 34 is placed on the lower end portion of the auxiliary retaining wall 18 constructed outside the construction surface, even if the auxiliary retaining wall 18 is constructed outside the construction surface, The necessary strength can be provided.

  Further, the retaining wall 14 and the auxiliary retaining wall 18 are constructed at positions along the underground outer wall 12, and the slab 20 and the structural frame 16 are left, leaving the retaining wall 14, the auxiliary retaining wall 18, and the frame 10 surrounding the retaining wall 14. Therefore, the work space can be increased in the basement floor at the time of dismantling and construction, and workability is improved.

  Moreover, since the existing underground structure M is opened and dismantled, a large heavy machine can be used during dismantling, and the dismantling material can be easily separated and carried out, thereby improving the workability.

  Further, since the retaining wall 14 and the auxiliary retaining wall 18 are constructed using the lath mold unit 30 which is a discarded mold, the demolding work is not required, the construction period can be shortened, and the retaining wall 14 and the auxiliary retaining wall 18 can be constructed. Improves.

  In addition, although an example of embodiment was demonstrated about this invention, this invention is not limited to this embodiment, Other various embodiment is possible within the scope of the present invention.

For example, in the above embodiment, the existing underground structure M has a four-floor structure, and the fourth-floor portion is backfilled with the dismantling gala G. However, the existing underground structure M may be any number of floors, and the place to be backfilled may be the construction ground. What is necessary is just to determine suitably based on the required intensity | strength.

  Moreover, in the said embodiment, although the retaining wall 14 and the auxiliary retaining wall 18 were constructed | assembled in the basement 2nd floor and the underground 3rd floor part, if the intensity | strength which can endure earth pressure can be provided, the retaining wall 14, An auxiliary retaining wall 18 may be constructed.

10, 16 frame (existing underground frame)
12 underground outer wall (existing underground outer wall)
14 Reservation Wall 18 Auxiliary Reservation Wall 20 Slab 30 Lath Form Unit (Discard Form)
34 Wrap concrete (concrete)
40 Construction Pillar G Demolition Gala M Existing Underground Structure

Claims (4)

After temporarily installing a retaining wall in the construction surface of the existing underground frame orthogonal to the existing underground outer wall to be left as a retaining wall, and supporting the existing underground outer wall to the retaining wall,
Removing the slab between the existing underground structures ,
The construction pillar of a new building is built while supporting the existing underground outer wall with the retaining wall ,
Underground demolition method. An auxiliary retaining wall is temporarily installed outside the surface of the existing underground structure that interferes with the true pillar of the new building,
Then, the existing underground structure that interferes with the true pillar of the new building is removed.
The underground demolition method according to claim 1.   The underground demolition method according to claim 2, wherein concrete for reinforcement is placed on a lower end portion of the auxiliary retaining wall temporarily installed outside the surface of the existing underground frame.   The underground demolition method according to claim 2 or 3, wherein the retaining wall and the auxiliary retaining wall are temporarily installed using a discarded formwork.

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