JP4474965B2 - Leg fixing method for building - Google Patents

Description

  The present invention relates to a method for fixing a leg of a building suitable for installing a leg such as a steel tower or a bridge pier.

  Conventionally, as described below, as a method of installing steel towers and bridge piers, steel pipes are buried in the ground, and after the legs are inserted into the steel pipes, concrete is placed in the steel pipes. A method of fixing a leg material to concrete is known.

  That is, in the conventional leg fixing method of a building, as shown in FIG. 24, the hole 51 is provided while inserting the earth retaining casing 52 into the ground 50. Then, the reinforcing bar 53 and the steel pipe 54 are inserted into the casing 52.

  The reinforcing bar 53 and the steel pipe 54 are fixed by welding, or a flange portion (not shown) is provided at the upper end of the reinforcing bar 53, and the steel pipe 54 is placed and fixed on the flange portion.

  Next, as shown in FIG. 25, concrete 55 is placed in the casing 52 using a tremy tube (not shown) or the like. The concrete 55 is placed up to the vicinity of the lower end of the steel pipe 54.

  Next, as shown in FIG. 26, the concrete 55 containing slime floating above the concrete 55 is removed by suction, and the upper surface of the concrete 55 is made to substantially coincide with the lower end of the steel pipe 54.

  Next, as shown in FIG. 27, after the casing 52 is pulled out and the concrete 55 is hardened, a natural ground around the steel pipe 54 is excavated to provide a recess 56 around the steel pipe. Subsequently, a mold frame 57 is installed around the steel pipe 54 in the recess 56.

  If there is a possibility that the groundwater 58 may flow into the recess 56, as shown by the wavy line in FIG. 27, the sheet pile 59 is driven around the steel pipe 54 at an appropriate interval, and the groundwater accumulates in the recess 56 prevent.

  Next, as shown in FIG. 28, the concrete 60 is placed up to the gap between the mold frame 57 and the steel pipe 54 and the vicinity of the leg installation planned position in the steel pipe 54.

  Next, as shown in FIG. 29, after the concrete 60 is hardened, the formwork 57 is removed, and the recesses 56 around the steel pipe 54 are backfilled with earth and sand 61.

  Next, as shown in FIG. 30, a leg member 62 in a building such as a steel tower or a bridge girder is inserted into the steel pipe 54 and installed on the concrete 55. Then, concrete 63 is placed in the steel pipe 54. Thereby, the fixing work of the leg material 62 is completed.

  Note that the leg member 62 is provided with a plurality of support plates 65 projecting from each other at an appropriate interval on the outer peripheral side thereof. When these support plates 65 are locked to the concrete 63, the fixing force of the legs 62 increases.

  However, in the conventional fixing method for the legs of the building, it is necessary to provide a recess 56 around the steel pipe 54 in order to install the formwork 57, and it is necessary to refill the recess 56 with earth and sand when the work is completed. For this reason, there is a problem that the number of work steps increases.

  Further, when the groundwater level 58 is high, the groundwater 58 flows out into the recess 56, and therefore, a large number of sheet piles 59 must be driven around the steel pipe 54 to prevent this, and the work man-hours further increase. was there. Further, when the sheet pile 59 is temporarily installed, there is a problem that when the sheet pile 59 is removed, a space is generated after the sheet pile 59 is pulled out, leading to a decrease in the pulling-out resistance of the pile and an increase in the horizontal displacement.

  This invention is made in view of such a problem, and makes it a subject to provide the leg fixing method of the building which can reduce an operation man-hour.

  The present invention employs the following means in order to solve the above problems. That is, the present invention provides a hole in the ground while inserting a cylindrical member for earth retaining in the ground, a reinforcing bar is provided on the bottom side in the cylindrical member, and a cylindrical shape for concrete restraint on the reinforcing bar A member is provided, and a building leg is arranged in the concrete-constraining tubular member, between the earth retaining tubular member and the concrete-constraining tubular member, and for the concrete restraint. A method for fixing a leg of a building, wherein concrete is placed in a cylindrical member, and the leg member is fixed to the concrete in the cylindrical member for restraining the concrete by removing the cylindrical member for earth retaining. When placing the concrete, the concrete is placed in the concrete-constrained tubular member in a state where the concrete is placed to the vicinity of the lower end of the concrete-constrained tubular member. Providing an inner lid for preventing the rise, closing the upper opening of the concrete-constraining tubular member with an outer lid, placing concrete from the outer lid, and Fill concrete between the concrete-constrained tubular member, remove the earth retaining tubular member and the outer lid, and after the concrete has hardened, remove the inner lid, The legs are fixed to the concrete in the concrete-constrained tubular member by inserting the legs into the tubular member and placing concrete in the concrete-constrained tubular member. It is characterized by that.

  In the present invention, when the upper opening of the concrete-constraining tubular member is closed with an outer lid and concrete is placed from above, the concrete does not enter the concrete-constraining tubular member, and the concrete-constraining tubular shape It flows down into the gap between the member and the tubular member for earth retaining.

  Therefore, the concrete can be filled easily and reliably in a relatively narrow gap between the concrete-constraining tubular member and the earth retaining tubular member.

  Here, after placing the concrete up to the upper side of the outer lid, the guide member is formed by removing the tubular member for earth retaining by removing the tubular member for earth retaining. It can be filled with the concrete placed on the upper side of the outer lid.

  In this case, since it is not necessary to post-cast concrete into the gap generated by removing the soil retaining tubular member, the number of work steps can be further reduced.

  The outer lid is preferably conical. In this case, the concrete cast from above the outer lid flows down along the inclined surface of the outer lid, so that the concrete can be reliably filled between the tubular member for earth retaining and the tubular member for concrete restraint. .

The above-described configurations can be combined with each other without departing from the spirit of the present invention.

  As described above, according to the present invention, it is possible to eliminate the need to install the sheet frame in the recessed portion by the mold frame, the recessed portion, and the groundwater in the leg fixing portion, so that the number of work steps can be greatly reduced.

  In addition, since the concrete can be easily and surely filled into a relatively narrow gap between the soil retaining tubular member and the concrete restraining tubular member, the number of work steps can be greatly reduced.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In the building leg fixing method according to the present invention, first, as shown in FIG. 1, a steel pipe casing 12, which is a cylindrical member for earth retaining, is inserted into the ground 10, and a hole 11 is formed in the ground 10. Is provided.

  Next, a steel bar 14 which is a reinforcing bar, in this example, a reinforcing bar 13 and a cylindrical member for constraining concrete, is inserted into the casing 12. As shown in FIG. 2, the reinforcing bar 13 and the steel pipe 14 are welded in advance by a welding portion 15 in advance. Then, the reinforcing bar 13 and the steel pipe 14 are integrated into the casing 12 in an integrated state. An appropriate reinforcing bar may be used instead of the reinforcing bar 13.

  As shown in FIG. 3, a plurality of ring-shaped concrete locking members 16 are provided on the inner peripheral surface of the steel pipe 14 at appropriate intervals.

  When an upward load is applied to the leg member 30 (see FIG. 21) installed in the steel pipe 14, the concrete 31 fixed around the leg member 30 is pulled upward. It is borne by the member 16.

  In place of fixing the reinforcing bar 13 and the steel pipe 14 by welding as described above, a flange portion 17 is provided at the upper end of the reinforcing bar 13 as shown in FIG. Can be mounted and fixed.

  In this case, after inserting the reinforcing bar 13 into the casing 12, the steel pipe 14 is inserted into the casing 12 and placed on the flange portion 17 of the reinforcing bar 13 to connect the reinforcing bar 13 and the steel pipe 14.

  As described above, after inserting the reinforcing bar 13 and the steel pipe 14 into the casing 12, as shown in FIG. 6, while gradually raising the casing 12 using a tremy pipe (not shown) or the like, Concrete 18 is placed.

  As shown in FIG. 7, the concrete 18 is filled in the vicinity of the lower end of the steel pipe 14, in this example, slightly above the lower end, but may be slightly below the lower end. Then, the slime 19 is generated on the upper side of the concrete 18. Therefore, as shown in FIG. 8, the slime 19 generated on the concrete 18 is removed by suction using a pipe 20 or the like.

  In addition, since the movement of the pipe 20 becomes easy by making the front-end | tip of the pipe 20 below the lower end part of the steel pipe 14 at the time of attraction | suction of the slime 19 etc., the attraction | suction work of the slime 19 etc. becomes easy.

When the steel pipe 14 is placed and connected on the flange portion 17 of the reinforcing bar 13 (see FIG. 4), after inserting the reinforcing bar 13 into the hole 11, the concrete 18 is struck before the steel pipe 14 is inserted. If the steel pipe 14 is inserted after the slime 19 and the like are sucked and removed, the pipe 20 can be easily moved when the slime 19 is sucked, so that the work of sucking and removing the slime 19 and the like is facilitated.

  Next, as shown in FIG. 9, concrete 21 is placed on the concrete 18 in the steel pipe 14 to a predetermined height. Thereafter, as shown in FIG. 10, the inner lid 22 is placed on the concrete 21 in the steel pipe 14 and fixed to the steel pipe 14.

  As shown in FIG. 11, the inner lid 22 has a circular first inner lid 23 and a second inner lid 24, and the first and second inner lids 23 and 24 are arranged so as to overlap each other. Yes.

  The first inner lid 23 is made of a material that can be reduced by a compressive force, such as wood. As shown in FIG. 12, the first inner lid 23 is divided into a plurality of parts by dividing lines 23a provided on the radial lines.

  In this example, the first inner lid 23 is equally divided into four blocks 25. Further, the diameter of the first inner lid 23 is slightly larger than the inner diameter of the steel pipe 14. A concrete stripping agent is applied to the inner surface of the first inner lid 23. Thereby, removal of the 1st inner lid 23 becomes easy.

  As shown in FIG. 13, the first inner lid 23 has four blocks 25 aligned in a circular shape and inserted into the steel pipe 14. If it does so, each block 25 will be compressed by the internal peripheral surface of the steel pipe 14, and the blocks 25 and the block 25 and the steel pipe 14 will closely_contact | adhere.

  As shown in FIG. 14, a plurality of fixing jigs 26 are provided on the outer peripheral side of the second inner lid 24. As shown in FIG. 15, these fixing jigs 26 are configured to be able to enter and exit from the outer periphery of the second inner lid 24. In this example, a screw member is used as the fixing jig 26.

  The diameter of the second lid 24 is smaller than the inner diameter of the steel pipe 14. When the second lid 24 is fixed in the steel pipe 14, the fixing jig 26 is extended and pressed against the inner surface of the steel pipe 14. The fixing jig 26 is preferably arranged below the concrete locking member 16 provided in the steel pipe 14. Further, as shown in FIG. 16, a hanging jig 27 is provided on the upper surface of the second inner lid 24.

  After attaching the inner lid 22 in the steel pipe 14, as shown in FIG. 17, an outer lid 28 is attached to the upper end of the steel pipe 14 to close the upper opening of the steel pipe 14. The outer lid 28 has a substantially conical shape, and has an outer diameter equal to or larger than the outer diameter of the steel pipe 14 and smaller than the inner diameter of the casing 12.

  In this example, the outer diameter of the outer lid 28 is substantially the same as the outer diameter of the steel pipe 14. A plurality of hanging jigs 33 are provided on the outer peripheral side of the outer lid 28.

  After the outer lid 28 is attached to the upper end of the steel pipe 14, as shown in FIG. 18, concrete 29 is placed in the casing 12 from the upper side of the outer lid 28, and the upper side of the outer lid 28, in this example, the outer lid 28 is placed. Concrete 29 is filled up to the vicinity of the upper end of.

  As a result, the concrete 29 placed on the outer lid 28 flows down along the inclined surface of the outer lid 28 and is surely filled into the gap between the steel pipe 14 and the casing 12. Further, the weight of the concrete 29 placed between the steel pipe 14 and the casing 12 acts on the concrete 18 in the steel pipe 14, but the concrete 18 is raised because the upper surface of the concrete 18 is sealed by the inner lid 22. Can be prevented.

Next, as shown in FIG. 19, before the concrete 29 hardens, the casing 12 is slowly pulled up and removed. At this time, a gap is formed in the portion occupied by the casing 12, but the concrete 29 filled above the outer lid 28 flows into the gap and is filled.

  After that, as shown in FIG. 20, the outer lid 28 is removed and the concrete 29 is cured. Then, after the concrete 29 is hardened, as shown in FIG. 21, the inner lid 22 is removed and a building leg member 30 is inserted into the steel pipe 14 and installed on the concrete 18. The leg member 30 is provided with a bearing plate 34. After that, as shown in FIG. 22, concrete 31 is cast and filled in the steel pipe 14.

  Next, as shown in FIG. 23, a footing 32 is provided at the upper end portion of the steel pipe 14 for corrosion protection of the steel pipe 14. Thereby, the fixing work of the leg member 30 is completed. By installing the legs 30 in this manner, the legs 30 are firmly installed in the ground 10, so that a heavy building such as a steel tower or a bridge girder can be attached and securely held on the legs 30.

  As described above, in the present invention, when placing concrete on the outer peripheral side of the steel pipe 14, the casing 12 is left and the concrete is placed between the casing 12 and the steel pipe 14, so that the steel pipe is conventionally used. There is no need to provide a formwork outside of 14. Therefore, work man-hours can be reduced.

  Further, since the mold assembly operation is not required, there is no need to provide a recess for the mold assembly operation around the steel pipe 14. Furthermore, even when the groundwater level is high, it is not necessary to provide a water stop wall such as a sheet pile around the steel pipe 14, so that the number of work steps can be greatly reduced.

  Further, the upper opening of the steel pipe 14 is closed with a substantially conical outer lid 28, and a concrete 29 is simply placed from above the outer lid 28 to form a relatively narrow gap between the steel pipe 14 and the casing 12. Since the concrete 29 can be reliably placed, the number of work steps can be further reduced.

  Furthermore, since the gap caused by the removal of the casing 12 can be automatically filled with the concrete 29 placed above the outer lid 28, the concrete post-working operation can be omitted.

It is sectional drawing which shows the installation state of the casing which concerns on embodiment, a reinforcing bar rod, and a steel pipe. It is sectional drawing which shows the coupling | bonding method of the reinforcing bar rod and steel pipe which concerns on embodiment. FIG. 3 is a view taken in the direction of arrow A in FIG. 2. It is sectional drawing which shows another joining method of the reinforcing bar rod and steel pipe which concerns on embodiment. It is a B arrow line view of FIG. It is sectional drawing which shows the method of placing concrete in the casing which concerns on embodiment. It is sectional drawing which shows the slime on the concrete which concerns on embodiment. It is sectional drawing which shows the method of carrying out the suction removal of the slime produced on the concrete which concerns on embodiment. It is sectional drawing which shows the placement height of the concrete in the steel pipe which concerns on embodiment. It is sectional drawing which shows the state which installed the inner cover in the steel pipe which concerns on embodiment. It is sectional drawing which shows the installation state of the inner cover which concerns on embodiment. It is a top view showing the 1st inner lid which constitutes the inner lid concerning an embodiment. It is sectional drawing which shows the contact | adherence state of the 1st inner cover and steel pipe which concern on embodiment. It is a top view which shows the 2nd inner cover which comprises the inner cover which concerns on embodiment. It is sectional drawing which shows the state which fixed the 2nd inner cover which concerns on embodiment to the steel pipe. It is a side view showing the 2nd inner lid concerning an embodiment. It is sectional drawing which shows the state which installed the outer cover in the upper end part of the steel pipe which concerns on embodiment. It is sectional drawing which shows the method of placing concrete in a casing from the upper direction of the outer cover which concerns on embodiment. It is sectional drawing which shows the removal method of the casing which concerns on embodiment. It is sectional drawing which shows the state which removed the outer cover from the upper end part of the steel pipe which concerns on embodiment. It is sectional drawing which shows the state which has arrange | positioned the leg part of the building in the steel pipe which concerns on embodiment. It is sectional drawing which shows the method of placing concrete around the leg material which concerns on embodiment. It is sectional drawing which shows the method of forming the footing for steel pipe corrosion prevention in the upper part side of the leg material which concerns on embodiment. It is sectional drawing which shows the installation method of the steel pipe which concerns on a prior art example, a reinforcing bar rod, and a casing. It is sectional drawing which shows the method of placing concrete in the casing which concerns on a prior art example. It is sectional drawing which shows the method of placing concrete in the steel pipe which concerns on a prior art example. It is sectional drawing which shows the method of providing a recessed part around the formwork which concerns on a prior art example. It is sectional drawing which shows the method of placing concrete between the formwork and steel pipe which concern on a prior art example. It is sectional drawing which shows the method of refilling earth and sand in the recessed part provided around the steel pipe which concerns on a prior art example. It is sectional drawing which shows the method of placing concrete around the leg part which concerns on a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Ground 11 Hole 12 Casing 13 Reinforcement rod 14 Steel pipe 16 Concrete locking member 15 Welding part 17 Flange part 18, 21, 29, 31, 55, 60, 63 Concrete 19 Slime 20 Pipe 22 Inner lid 23 First inner lid 24 First 2 Inner lid 25 Block 26 Fixing jig 27 Suspension jig 28 Outer lid 30 Leg material 32 Footing 33 Suspension jig 34 Bearing plate 50 Ground 51 Hole 52 Casing 53 Reinforcement rod 54 Steel pipe 56 Recess 57 Mold frame 58 Ground water 59 Sheet pile 61 Earth and sand 62 Leg material 65 Bearing plate

Claims (4)

While inserting a cylindrical member for earth retaining into the ground, a hole is provided in the ground, a reinforcing bar is provided on the bottom side in the cylindrical member for earth retaining, and a cylindrical member for concrete restraint is provided on the reinforcing bar. And placing a building leg in the tubular member for constraining concrete, between the tubular member for earth retaining and the tubular member for constraining concrete, and for the concrete constraining tube In the method of fixing a leg of a building, the concrete is placed in the member, and the leg member is fixed to the concrete in the cylindrical member for restraining the concrete by removing the tubular member for earth retaining,
When the concrete is placed, the concrete is prevented from rising into the concrete-constraining tubular member in a state where the concrete is placed to the vicinity of the lower end of the concrete-constraining tubular member. Provide an inner lid,
Close the upper opening of the concrete-constrained tubular member with an outer lid,
Placing concrete from above the outer lid, filling concrete between the tubular member for earth retaining and the tubular member for constraining concrete,
Remove the tubular member for earth retaining and the outer lid, after the concrete is cured, remove the inner lid,
The leg member is inserted into the concrete-constraining tubular member, and concrete is placed in the concrete-constraining tubular member, whereby the leg member is placed in the concrete-constraining tubular member. A method for fixing a leg of a building, characterized by being fixed to concrete.   After placing the concrete up to the upper side of the outer lid, by removing the tubular member for earth retaining, a gap generated by removing the tubular member for earth retaining is removed from the outer lid. The method for fixing a leg of a building according to claim 1, wherein the concrete is filled with the concrete placed on the upper side.   3. The leg fixing of a building according to claim 1 or 2, wherein the inner lid is a circular lid and has a fixing jig for installation at an arbitrary position in a cylindrical member for constraining concrete. Method.   4. The method for fixing a leg of a building according to claim 1, wherein the outer lid has a substantially conical shape.

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