JP2007063911A - Technique for reforming and constructing underfloor portion around column leg portion of existing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for constructing a new beam and a new slab with high quality reliably integrated with an existing floor even in work for reinforcement at the underfloor side and performing safe reforming work such as base isolation or earthquake-proof reinforcement for an underfloor portion while keeping an overfloor portion around a column leg portion of an existing structure in an usable condition. <P>SOLUTION: The technique comprises a step of excavating the underfloor portion 8, a step of assembling a formwork in the underfloor portion 8, filling concrete in the formwork to construct the new beam 1 integrated with an existing floor 3 with no gap, curing the new beam 1 until developing its predetermined strength, and then removing the formwork therefrom, a step of assembling a formwork in a position adjacent to the new beam 1, and filling concrete in the formwork to construct the new slab 2 integrated with the existing floor 3 and the new beam 1 with no gap, and a step of curing the new slab 2 until developing its predetermined strength, removing the formwork therefrom, and performing reforming work such as base isolation or earthquake-proof reinforcement for the underfloor portion 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention belongs to the technical field of a construction method for reconstructing the underfloor portion around the column base of an existing structure, and more specifically, while keeping the above-floor portion of the existing structure usable (so-called This is related to a method that can reliably reinforce the existing floor so that it can safely perform seismic isolation or seismic retrofitting in the lower part of the floor.

  Conventionally, when performing seismic isolation (so-called seismic isolation retrofit work) or retrofitting work such as seismic reinforcement in the lower floor area around the column base of an existing structure, the existing foundation is temporarily used as a construction method. Generally, a method of supporting a load of an existing structure by installing a support pile under the foundation beam in the vicinity of is adopted. At that time, it is assumed that the existing frame such as the existing foundation beam to be temporarily received has sufficient strength, or that the existing frame such as the existing foundation beam is reinforced in advance. In addition, when expanding an existing structure, it may be necessary to reinforce an existing frame such as an existing foundation beam in advance.

  As a method for reinforcing the existing casing, for example, there are techniques as shown in FIGS. 10 to 13 of Patent Document 1 and FIG. 5 of Patent Document 2 described below. These technologies commonly dismantle and remove the bottom floor slab, root the surrounding ground of the foundation beam, and reinforce it by newly installing the foundation beam (for details, see [ 0003] to [0005] and paragraph [0003] of the document 2). In this case, the reinforcement work for the existing frame has been carried out by dismantling and removing the floor slab in advance, so that the work can be carried out using a wide work space without any restrictions on the work space. As a result, existing foundation beams can be reinforced with high-quality concrete.

  However, the existing floor is left as it is in the case of renovation work such as seismic isolation or seismic reinforcement in the lower part of the existing structure while keeping the upper part of the floor around the column base part usable. Reinforcement work must be performed from under the floor in the state, and there is a problem that the work space is restricted.

  Therefore, conventionally, in order to reinforce the existing frame in the lower floor portion in a state where the upper floor portion around the column base portion of the existing structure can be used, as shown in FIG. The new beam 1 and the new slab 2 were constructed at the same time and integrated with the existing floor 3. Or the existing floor 3 was reinforced using steel instead of concrete. In addition, a technique according to Patent Document 1 has been proposed.

  By the way, in Patent Document 1, as shown in FIGS. 1 to 9 of the same document 1, a floor base plate adjacent to the foundation 2 is supported by a support 15 without removing the soil concrete floor (existing floor) 11. Is excavated and deleted partially, and after excavation, the foundation beam 14 is reinforced to extend the excavation of the floor foundation to the center while receiving the interstitial concrete floor 11 by the steel frame 19 and hitting the foundation beam 14 to the side A technology is disclosed in which a reinforcing foundation beam 14 is temporarily received by a bottom plate reinforcing pile 22 that is reinforced with concrete that has been press-fitted, and the floor foundation plate is dug down together with the foundation foundation plate so as to be seismically isolated (the same document 1). See summary).

JP 2001-317217 A JP 2001-311314 A

  By placing concrete from the lower floor side to the lower floor part, the new beam and the new slab are simultaneously constructed and integrated with the existing floor. That is, it is extremely difficult to confirm whether or not a new beam and a new slab that are securely integrated with an existing floor can be constructed, and there is a problem in quality. The technique according to Patent Document 1 has a similar problem. In addition, there are problems that the number of members and the construction process are large, and the work has a long period of time, which increases the cost.

  In addition to the problem that strength is inferior to concrete compared to concrete, the technique of reinforcing the existing floor using the steel material is restricted in terms of the work space, and therefore, a restriction is imposed on the carry-in size of the steel material. There was a risk that steel could not be carried in.

  The purpose of the present invention is to construct high-quality new beams and new slabs that are securely integrated with the existing floor, even for reinforcement work from below the floor, and use the upper part of the floor around the column base of the existing structure It is to provide a construction method that can safely perform reconstruction work such as seismic isolation and seismic reinforcement in the lower part of the floor while keeping it in a possible state.

As a means for solving the above-mentioned problem, the construction method for renovating the underfloor portion around the column base portion of the existing structure according to the invention described in claim 1 is to remodel the underfloor portion around the column base portion of the existing structure. In the construction method,
Excavating the underfloor portion;
The formwork is assembled in the lower part of the floor, a concrete beam is filled into the same formwork to construct a new beam that is integrated with the existing floor without a gap, and after the new beam is cured until it exhibits a predetermined strength, the formwork Demolding, and
Building a formwork at a position adjacent to the new beam, filling the same formwork with concrete, and constructing a new slab that is integrated with the existing floor and the new beam without gaps;
After the new slab is cured until it exhibits a predetermined strength, the mold is removed from the mold, and a renovation work such as seismic isolation and seismic reinforcement is performed on the lower part of the floor.

The method of reconstructing the underfloor portion around the column base of the existing structure according to the invention described in claim 2 is a method of reconstructing the underfloor concrete floor portion around the column base of the existing structure,
Excavating the lower floor portion and installing a support material at the excavation site to support the existing floor;
The formwork is assembled in the lower part of the floor, a concrete beam is filled in the same formwork to construct a new beam that is integrated with the existing floor without any gap, and after the new beam is cured until it exhibits a predetermined strength, the formwork is Demolding, and
Constructing a formwork at a position adjacent to the new beam, filling the same formwork with concrete, and constructing a new slab that is integrated with the existing floor and the new beam without gaps;
After the new slab is cured until it exhibits a predetermined strength, the mold is removed from the mold, the support material is removed, and the underfloor part is subjected to reconstruction work such as seismic isolation and seismic reinforcement. A construction method for reconstructing the underfloor part around the column base of an existing structure, characterized by

  According to a third aspect of the present invention, in the construction method for reconstructing the lower floor portion around the column base portion of the existing structure described in the first or second aspect, a new beam or a new slab is provided on the existing floor. It is characterized by providing a hole for confirming that it is integrated with no gap.

  The invention described in claim 4 is a construction method for reconstructing the underfloor portion around the column base portion of the existing structure according to any one of claims 1 to 3, wherein a new beam is provided at the upper end of the formwork, Or it is characterized by providing a notch or a confirmation sleeve for confirming that the new slab is integrated with the existing floor without any gap.

  The invention described in claim 5 is a method for reconstructing the underfloor part around the column base part of the existing structure according to any one of claims 1 to 4, after demolding the formwork of the new beam When there is a gap between the new beam and the existing floor, the new beam and the existing floor are integrated without gaps by injecting a filler such as grout with high fluidity into the gap. It is characterized by doing.

  The invention described in claim 6 is a method of remodeling the underfloor part around the column base part of the existing structure described in any one of claims 1 to 5, after demolding the formwork of the new slab In the case where a gap is formed between the new slab and the existing floor, or the new slab and the new beam, by injecting a filler such as grout having high fluidity into the gap, It is characterized by unifying existing floors and new beams without gaps.

  The invention described in claim 7 is a construction method for reconstructing an underfloor portion around the column base portion of the existing structure according to any one of claims 1 to 6, wherein the new beam includes a PC steel bar, a PC steel It is characterized by using a PC steel material such as a wire to increase the strength and rigidity by introducing prestress.

  The invention described in claim 8 is a construction method for reconstructing the underfloor portion around the column base portion of the existing structure according to any one of claims 1 to 7, wherein the new slab is made of a PC steel bar, PC steel It is characterized by using a PC steel material such as a wire to increase the strength and rigidity by introducing prestress.

  According to the construction method for renovating the underfloor part around the column base part of the existing structure according to the invention described in claims 1 to 6, the on-floor part around the column base part of the existing structure is made usable. In addition, it is possible to construct and reinforce high-quality new beams and new slabs that are securely integrated with the existing floor, so it is necessary to safely perform reconstruction work such as seismic isolation and seismic reinforcement under the floor. Can do.

  According to the construction method in which the underfloor part around the column base part of the existing structure according to the inventions according to claim 7 and claim 8 is renovated, in addition to the above effects, the reinforcement with higher strength and rigidity can be performed. it can.

  The construction method for reconstructing the underfloor portion around the column base portion of the existing structure according to the present invention is carried out as follows in order to achieve the effects of the above-described invention.

  FIGS. 1-5 has shown the construction method which renovates the underfloor part around the column base part of the existing structure which concerns on the invention described in Claim 2 in steps.

  In this method, while keeping the upper part 7 around the column base of the existing structure usable (so-called), the underfloor part 8 can be safely remodeled and seismically strengthened. In this method, the existing floor 3 is securely reinforced. First, the lower floor portion 8 is excavated, and a plurality of support members 6 are installed at the excavation site. 3 is supported (see FIG. 1).

  Although the existing floor 3 which concerns on the example of illustration is implemented with the soil concrete floor 3, it is not limited to this, It can implement also with a normal concrete floor substantially the same. Note that the support material 6 is not particularly required when the concrete floor is used (the invention according to claim 1).

  Next, necessary reinforcement is applied to the lower floor portion 8, a formwork is assembled, concrete is filled in the same formwork, and the new beam 1 that is integrated with the existing floor 3 without a gap is constructed (see FIG. 2). .

  As a method of constructing the new beam 1 that is integrated with the existing floor 3 without a gap, in this embodiment, as shown in FIG. 2, the new beam 1 to be constructed is separated from the existing floor 3 with a gap. A plurality of holes 9 for confirming that they are integrated are formed with a plurality of holes (the invention according to claim 3). The hole 9 also serves as an air vent hole for placing concrete. Using this hole 9, it is visually confirmed that the existing floor 3 and the new beam 1 to be constructed are reliably integrated. For example, based on the fact that the concrete is filled to the extent that it overflows from the hole 9, it is estimated that the concrete is filled densely and integrated with the existing floor 3. In addition, it is preferable to close the hole 9 with a material (for example, high-strength concrete) equal to or higher than the strength of the concrete immediately after the concrete is placed.

  In addition, when the hole cannot be drilled in the floor 3 due to the restriction of the upper floor portion 7, the shape of the formwork is devised so that the existing floor 3 and the newly constructed beam 1 are integrated. It is preferable. Specifically, although not shown, by providing a notch or a confirmation sleeve at the upper end of the mold (the invention according to claim 4), the concrete can be removed from the notch (or the confirmation sleeve). It is inferred that the concrete is filled densely and integrated with the existing floor 3 on the basis of filling to the extent that the overflowing.

  Next, after the new beam 1 is cured until it exhibits a predetermined strength, the mold is removed.

  Here, the adhesion state of the concrete between the existing floor 3 and the newly constructed beam 1 will be confirmed again. When it is confirmed that the concrete is densely filled and the existing floor 3 and the new beam 1 are integrated with no gap and the high-quality new beam 1 can be constructed, the process proceeds to the next step. However, when a gap is generated between the new beam 1 and the existing floor 3, the new beam 1 and the existing floor 3 can be obtained by injecting a filler such as grout having high fluidity into the gap. Are integrated without gaps (invention of claim 5).

  Next, necessary reinforcement is provided at a position adjacent to the new beam 1, a formwork is assembled, concrete is filled into the same formwork, and the existing floor 3 and the new beam 1 are integrated with no gap. A slab 2 is constructed (see FIG. 3).

  As a method for constructing a new slab 2 that is integrated with the existing floor 3 and the new beam 1 without a gap, as shown in FIG. 3, the new slab 2 to be constructed is also constructed on the existing floor 3. A plurality of holes 9 for confirming that the existing floor 3 and the new beam 1 are integrated with no gap are formed (invention according to claim 3). The hole 9 also serves as an air vent hole for placing concrete. Using this hole 9, it is visually confirmed that the existing floor 3 and the newly installed beam 1 and the newly constructed slab 2 are reliably integrated. For example, it is estimated that the concrete is densely filled and integrated with the existing floor 3 and the new beam 1 on the basis that the concrete is filled to the extent that it overflows from the hole 9. In addition, it is preferable to close the hole 9 with a material (for example, high-strength concrete) equal to or higher than the strength of the concrete immediately after the concrete is placed.

  If the hole cannot be drilled in the existing floor 3 due to the restriction of the upper floor portion 7, the shape of the formwork is devised to construct the existing slab 2 constructed with the existing floor 3 and the new beam 1. It is preferable to achieve integration. Specifically, although not shown, by providing a notch or a confirmation sleeve at the upper end of the mold (the invention according to claim 4), the concrete can be removed from the notch (or the confirmation sleeve). It is inferred that the concrete is solidly filled and integrated with the floor 3 and the newly installed beam 1 on the basis of filling to the extent that the water overflows.

  Next, after the new slab 2 is cured until it exhibits a predetermined strength, the mold is removed and the support material 6 is removed (see FIG. 4).

  Here, the adhesion state of the concrete between the existing floor 3 and the newly installed beam 1 and the newly constructed slab 2 will be confirmed again. If it is confirmed that the concrete is densely filled and the existing floor 3 and the new beam 1 and the new slab 2 are integrated with no gap, and a high-quality new slab 2 can be constructed, Proceed to step. However, when a gap is generated between the new slab 2 and the existing floor 3 or between the new slab 2 and the new beam 1, by injecting a filler such as grout with high fluidity into the gap, The new slab 2, the floor 3 and the new beam 1 are integrated without a gap (the invention according to claim 6).

  Next, the underfloor portion 8 is subjected to reconstruction work such as seismic isolation and seismic reinforcement (the inventions according to claims 2 and 1 above).

  The renovation work of the underfloor portion 8 is not limited to the case where the underfloor portion 8 is subjected to seismic isolation, and refers to the overall construction of the underfloor portion 8 such as seismic reinforcement work for the existing foundation 5. As an example, when the underfloor part 8 is to be seismically isolated, as shown in FIG. 5, a bottom concrete (pressure board) 11 is constructed on the ground, and a new construction that has been constructed by a temporary receiving device 12 such as a support jack. The reaction force is applied to the beam 1 and a thin laminated rubber (seismic isolation device) 13 is installed on the existing foundation 5. In addition, as shown in FIG. 9 and FIG. 13 of patent document 1, and FIG. 5e of patent document 2, you may implement in the position directly under the existing foundation, as the site | part which carries out seismic isolation is not limited to this. The floor 3 is integrated with the newly established high-quality new beam 1 and the new slab 3 without any gaps, and has sufficient proof strength to receive temporarily, so that seismic isolation work can be performed safely and reliably. It can be done.

  As described above, according to the construction method according to claim 2 (Claim 1) described above, the existing floor 3 and the existing floor 3 can be securely connected while the on-floor portion 7 around the column base portion of the existing structure is in a usable state. Since the high-quality new beam 1 and the new slab 2 that are integrated into the building can be constructed and reinforced, the underfloor portion 8 can be safely subjected to reconstruction work such as seismic isolation and seismic reinforcement. The invention described in claim 2 is preferably used when the floor 3 requires a support material 6 such as a soil concrete floor 3, whereas the invention described in claim 1 3 is suitably employed when a support material 6 such as a normal concrete floor is not required.

  6A and 6B schematically show a construction method for reconstructing the underfloor portion around the column base portion of the existing structure according to the invention described in claim 7. In short, this construction method is different from the first embodiment in that the PC steel rod 14 is placed on the new beam 1 and the existing column 4 is centered on the new beam 1 prior to the construction of the new slab 2. The main difference is that the prestress is introduced by being arranged in the form of a cross-beam and being tensioned. Therefore, since the strength and rigidity of the newly installed beam 1 can be further increased, higher-quality reinforcement work can be performed as compared with the first embodiment. In addition, although illustration is abbreviate | omitted, also about the said newly installed slab 2, the PC steel rod 14 can be arrange | positioned (or extended) similarly and can be tensioned and prestress can be introduce | transduced (invention of Claim 8).

  7A and 7B schematically show different examples of the construction method for renovating the underfloor part around the column base part of the existing structure according to the invention described in claim 7. In short, as compared with the first embodiment, this construction method is a sheath in which a PC steel wire 15 is embedded in the new beam 1 in the new beam 1 as seen from the plane direction prior to the construction of the new slab 2. The main difference is that the pipe (not shown) is bent and arranged in a hooked manner around the existing column 4 and is pre-stressed by tension. ). Therefore, since the strength and rigidity of the newly installed beam 1 can be further increased, higher-quality reinforcement work can be performed as compared with the first embodiment. In addition, although illustration is abbreviate | omitted, also about the said newly installed slab 2, the PC steel wire 15 can be arrange | positioned (or extended), can be strained, and prestress can be introduce | transduced (invention of Claim 8).

  Although the embodiments have been described with reference to the drawings, the present invention is not limited to the embodiments shown in the drawings, and design modifications and application variations that are usually performed by those skilled in the art are within the scope not departing from the technical idea thereof. Note that it includes the range.

It is the elevation sectional view which showed the construction method which renovates the underfloor part around the column base part of the existing structure concerning the invention described in claim 2 in steps. It is the elevation sectional view which showed the construction method which renovates the underfloor part around the column base part of the existing structure concerning the invention described in claim 2 in steps. It is the elevation sectional view which showed the construction method which renovates the underfloor part around the column base part of the existing structure concerning the invention described in claim 2 in steps. It is the elevation sectional view which showed the construction method which renovates the underfloor part around the column base part of the existing structure concerning the invention described in claim 2 in steps. It is the elevation sectional view which showed the construction method which renovates the underfloor part around the column base part of the existing structure concerning the invention described in claim 2 in steps. A is an elevational sectional view showing a construction method for renovating the underfloor portion around the column base portion of the existing structure according to the invention described in claim 7, and B is a plan view thereof. A is an elevational sectional view showing a construction method for renovating the underfloor portion around the column base portion of the existing structure according to the invention described in claim 7, and B is a plan view thereof. It is the sectional elevation which showed the prior art.

Explanation of symbols

1 New beam 2 New slab 3 Existing floor (concrete concrete floor)
4 Existing pillar 5 Existing foundation 6 Support material 7 Floor part 8 Floor part 9 Confirmation hole 10 Concrete 11 Bottom concrete (pressure board)
12 Support jack (temporary receiving device)
13 Laminated rubber (Seismic isolation device)
14 PC steel bar 15 PC steel wire

Claims (8)

In the method of renovating the underfloor part around the column base of an existing structure,
Excavating the underfloor portion;
The formwork is assembled in the lower part of the floor, a concrete beam is filled into the same formwork to construct a new beam that is integrated with the existing floor without a gap, and after the new beam is cured until it exhibits a predetermined strength, the formwork Demolding, and
Building a formwork at a position adjacent to the new beam, filling the same formwork with concrete, and constructing a new slab that is integrated with the existing floor and the new beam without gaps;
The existing slab is cured until it exhibits a predetermined strength, and then the mold is removed from the mold, and the underfloor part is subjected to retrofitting work such as seismic isolation and seismic reinforcement. A method of renovating the underfloor area around the column base of the structure. In the method of renovating and constructing the lower part of the concrete floor around the column base of the existing structure,
Excavating the lower floor portion and installing a support material at the excavation site to support the existing floor;
The formwork is assembled in the lower part of the floor, a concrete beam is filled into the same formwork to construct a new beam that is integrated with the existing floor without a gap, and after the new beam is cured until it exhibits a predetermined strength, the formwork Demolding, and
Building a formwork at a position adjacent to the new beam, filling the same formwork with concrete, and constructing a new slab that is integrated with the existing floor and the new beam without gaps;
After the new slab is cured until it exhibits a predetermined strength, the mold is removed from the mold, the support material is removed, and the lower floor portion is subjected to reconstruction work such as seismic isolation and seismic reinforcement. A construction method for reconstructing the underfloor part around the column base of an existing structure, characterized by   3. The existing structure according to claim 1, wherein the existing floor is provided with a hole for confirming that the new beam or the new slab is integrated with the existing floor without a gap. A method of renovating the lower floor around the column base.   The upper end of the formwork is provided with a notch or a confirmation sleeve for confirming that the new beam or the new slab is integrated with the existing floor without any gap. Method of renovating the underfloor part around the column base of the existing structure described in any one of 3 above.   After removing the formwork of the new beam, if there is a gap between the new beam and the existing floor, by injecting a filler such as grout with high fluidity into the gap, The construction method for reconstructing the underfloor portion around the column base portion of the existing structure according to any one of claims 1 to 4, wherein the new beam and the existing floor are integrated without gaps.   After removing the mold of the new slab, if there is a gap between the new slab and the existing floor or between the new slab and the new beam, filling the gap with a highly fluid grout or the like By injecting a material, the new slab, the existing floor, and the new beam are integrated without gaps, and around the column base portion of the existing structure according to any one of claims 1 to 5, A method of renovating the underfloor part.   The new beam is tensioned by using a PC steel material such as a PC steel bar or a PC steel wire, and prestress is introduced to increase strength and rigidity, according to any one of claims 1 to 6. A method of reconstructing the underfloor area around the column base of the existing structure described.   The new slab is tensioned by using a PC steel material such as a PC steel bar or a PC steel wire, and prestress is introduced to increase strength and rigidity. A method of reconstructing the underfloor area around the column base of the existing structure described.

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