JP2010229709A - Foundation structure of temporary support and method for constructing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foundation structure of a temporary support, can decrease the amount of waste, which can reduce costs by reducing the labor and time for construction and demolition and noise problems, and can secure desired strength; and to provide a method for constructing the foundation structure. <P>SOLUTION: In precast concrete units 10 and 20, a plurality of segments 11-14 and 21-24 molded in a pre-split shape are closely arranged in a separable state in advance in the length direction of the precast concrete unit; and a tendon with predetermined prestress is extractably arranged in the length direction of the precast concrete unit in such a manner that first insertion holes 2 formed in the respective segments communicate with one another. In the segment, a first protrusion 31 or a first recess 32 is formed on a surface facing the length direction of the precast concrete unit; and the first recess or the first protrusion, which is fitted to the first protrusion or the first recess, is formed on a surface where the segments adjacent to each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a foundation structure of a temporary support column using a precast concrete unit and a construction method thereof.

  In civil engineering work, temporary struts may be constructed as necessary. The temporary support column is constructed to support, for example, a temporary bridge or a floor slab such as a road. After the temporary bridge or road is disassembled, the temporary support column is also dismantled and removed. Further, for example, in a long-span bridge composed of a plurality of members, the temporary support columns are dismantled and removed when the joining portions of the members are temporarily supported and the weight can be supported after the joining is completed. The foundation of such a temporary support column is installed on the ground without requiring a pile or the like, and reinforced concrete on-site casting is mainly applied in its construction.

  For example, Patent Document 1 is known as a method for constructing a temporary bridge constructed between a left bank and a right bank having a difference in ground height using a precast concrete foundation material.

  The construction method of the temporary bridge of Patent Document 1 is to install a precast concrete foundation material with a height corresponding to the difference in height on the discarded concrete on the lower shore after hardening of the discarded concrete placed in the ground on both banks is doing. And place the girder on the precast concrete foundation material and the abandoned concrete on the higher shore, install several main girder between these girder, and lay the lining board on these main girder Yes.

JP-A-7-292618

  The foundation of the temporary support column installed in the above-mentioned reinforced concrete site is destroyed and removed by a breaker or the like after the temporary support column is dismantled. In building and dismantling the foundation, it took time and labor to make the cast-in-place concrete. In particular, dismantling has become a cause of noise and vibration, and a large amount of waste such as concrete trash is generated, which is extremely irrational in terms of environment and economy.

  As a means for solving such irrationality, there is a method of introducing a precast concrete member into a concrete foundation portion as in Patent Document 1 described above. However, temporary bridges such as temporary bridges and roads are heavy, and the foundations supporting them are also heavy. In this case, there has been a problem that it takes a lot of labor to carry in and carry out the integrated precast concrete member produced in a factory or the like and to assemble it on site, which increases costs. Furthermore, there was a request to increase the strength when supporting a heavy temporary column. Further, for example, when a precast concrete member is divided and molded into a plurality of units in advance, these are carried in, a joining reinforcing bar or the like is inserted between the units, and grout is injected to be integrated. For this reason, it takes time and effort to integrate the precast concrete members, and dismantling takes time and labor similar to the cast-in-place concrete, which increases costs, and a large amount of waste is generated. It was.

  The present invention was devised in view of the above-described conventional problems, and can reduce the amount of waste, reduce the labor and time of construction and dismantling, noise problems, and reduce costs. An object of the present invention is to provide a foundation structure of a temporary support column and a method for constructing it, which can ensure a desired strength.

  The foundation structure of the temporary support column according to the present invention is a foundation structure of a temporary support column using a precast concrete unit, and the precast concrete unit is divided into a plurality of pieces formed in advance in the length direction. The segments are closely arranged in a separable state, and the precast concrete unit is connected to a first insertion hole formed in each of the segments in the length direction thereof, and has a predetermined prestress. Are disposed in a removable manner, and the first convex portion or the first concave portion is formed on a surface of the segment facing the length direction of the precast concrete unit, and the adjacent segments are opposed to each other. The surface is formed with a first concave portion or a first convex portion that is fitted into the first convex portion or the first concave portion.

  The precast concrete units are arranged side by side in a state in which at least two or more can be separated in the width direction, and these precast concrete units communicate with the second insertion holes formed in these segments in the width direction, A tension material having a predetermined pre-stress is detachably disposed, and the segment is formed with a second convex portion or a second concave portion on a surface facing the width direction of the precast concrete unit, and adjacent to the segment. The precast concrete unit that is opposed to each other is formed with second concave portions or second convex portions that are fitted into the second convex portions or the second concave portions.

  A lid portion that seals the first insertion hole or the second insertion hole from the outside is detachably disposed.

  Further, in the method for constructing the foundation structure of the temporary support column according to the present invention, the precast concrete unit is preliminarily divided into segments in the length direction, and then the plurality of segments are opposed to each other at the installation position. In a state where the surfaces can be separated while being separable, they are connected to the precast concrete unit, and the precast concrete unit is connected to the first insertion hole formed in each of the segments in the length direction thereof. It is characterized in that a material is removably inserted, a predetermined prestress is applied to the tension material, the precast concrete unit is integrated, and a temporary support column is installed on the precast concrete unit.

  At the installation position, the precast concrete units are arranged in parallel in at least two or more in the width direction, in a state where they can be separated while closely facing the opposing surfaces. A plurality of precast concrete units arranged side by side are connected through a second insertion hole formed in the segment, the tension material is removably inserted, and a predetermined prestress is applied to the tension material. And a temporary support column is installed on the plurality of precast concrete units.

  After dismantling the temporary struts installed on the one or more precast concrete units, after unloading the prestress of the tendon, the tendon is removed, and the one or more precast The concrete unit is separated into the segments so as to be divertable.

  In the foundation structure of the temporary support according to the present invention and the construction method thereof, the amount of waste can be reduced, the labor and time of construction and dismantling, noise problems can be reduced, and the cost can be reduced. The desired strength can be ensured.

It is a top view which shows suitable one Embodiment of the foundation structure of the temporary support | pillar concerning this invention. It is a side view of the foundation structure of the temporary support | pillar of FIG. It is a front view of the foundation structure of the temporary support | pillar of FIG. In FIG. 1, it is a principal part expanded side sectional view which shows the penetration hole by which the tension material is not arrange | positioned, and an insertion port periphery. FIG. 5 is a front view of FIG. 4. In FIG. 1, it is a sectional side view which shows the penetration hole and the insertion port periphery in the state by which the tension material was arrange | positioned. FIG. 7 is a front view of FIG. 6. In FIG. 1, it is a perspective view which shows A segment. It is the plane sectional view and side sectional view showing the bar arrangement state of A segment of FIG. In FIG. 1, it is a perspective view which shows B segment. In FIG. 1, it is a perspective view which shows C segment. In FIG. 1, it is a perspective view which shows D segment. In FIG. 1, it is a perspective view which shows E segment. In FIG. 1, it is a perspective view which shows F segment. In FIG. 1, it is a perspective view which shows G segment. In FIG. 1, it is a perspective view which shows H segment. In FIG. 4, it is a sectional side view which shows the other example of a cover part. It is a front view which shows the cover part of FIG.

  Hereinafter, a preferred embodiment of a foundation structure of a temporary support column and a construction method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a plan view of a foundation structure 1 of a temporary support column according to the present embodiment. 2 is a side view of FIG. 1, and FIG. 3 is a front view of FIG. FIG. 4 is an enlarged side cross-sectional view of the main part showing the insertion hole and the vicinity of the insertion opening where no tendon material is disposed. FIG. 5 is a front view of FIG. FIG. 6 is a side cross-sectional view showing the vicinity of the insertion hole and the insertion port in a state in which the tendon is disposed. FIG. 7 is a front view of FIG. In this embodiment, let the long side direction of the precast concrete units 10 and 20 formed in the rectangular shape shown by FIG. 1 be a length direction, and let a short side direction be the width direction. Further, as for the directions such as left and right, unless otherwise noted in the sentence, FIG. 1 is used as a reference.

  The foundation structure 1 of the temporary support column according to the present embodiment mainly includes a plurality of segments 11 to 14 in which the precast concrete units 10 and 20 and the precast concrete units 10 and 20 are divided and molded in advance in the length direction. 21 to 24, the first insertion hole 2 and the second insertion hole 3 formed in each of the segments 11 to 14 and 21 to 24, and a tension material. In the example of illustration, the two precast concrete units 10 and 20 are arranged in the width direction in the installation position. The precast concrete units 10 and 20 are composed of a plurality of segments 11 to 14 and 21 to 24 which are divided and molded in advance in the length direction, and these segments 11 to 14 and 21 to 24 are in a separable state. Closely arranged in a precast concrete unit. Here, “the plurality of segments 11 to 14 and 21 to 24 are closely arranged in a separable state” means that the opposing surfaces of the segments 11 to 14 and 21 to 24 are simply placed in close contact with each other. That is. That is, the adjacent segments do not pass through an adhesive material such as mortar at the time of arrangement, so that the segments 11 to 14 and 21 to 24 can be immediately separated if the tension material described later is pulled out. . Note that close does not mean that there is no gap between the opposing surfaces (the same applies hereinafter).

  Specifically, in the first precast concrete unit 10, the A segment 11 is arranged at the left end, the D segment 14 is arranged at the right end, and the B segment 12 and the C segment 13 are alternately arranged between them. Yes. On the other hand, in the second precast concrete unit 20, the E segment 21 is disposed at the left end, the H segment 24 is disposed at the right end, and the F segments 22 and the G segments 23 are alternately disposed therebetween.

  A first insertion hole 2 is formed in each of the segments 11 to 14 and 21 to 24 arranged in a precast concrete unit shape so as to penetrate in the length direction of the precast concrete units 10 and 20. In the example of illustration, the 1st penetration hole 2 is formed in three places at appropriate intervals in the long side direction of each segment 11-14, 21-24.

  At both ends 4 in the length direction of the precast concrete units 10 and 20, there are formed insertion ports 6 that are communicated with the first insertion hole 2 and into which the tension material is removably inserted. In the illustrated example, the insertion port 6 has a larger diameter than the first insertion hole 2 and is formed in a substantially square shape, and the tension member is fixed inside the insertion port 6 so that the tension member is fixed inside the insertion port 6. It is formed to be depressed toward the direction. In the first insertion hole 2 around the insertion opening 6, as shown in FIG. 4, substantially lattice-like grit bars 7 (fixing reinforcement reinforcing bars) are arranged.

  In the precast concrete units 10 and 20, the first insertion holes 2 formed in the segments 11 to 14 and 21 to 24 are communicated with each other in the length direction so that the prestressed tension material is detachable. Established. In the illustrated example, the tendon is formed of a well-known PC steel strand 8. After a predetermined prestress is applied to the PC steel stranded wire 8, both ends 8a thereof are fixed in the insertion port 6 with nuts 8b.

  A lid portion 9 that seals the insertion holes 2 and 3 from the outside is detachably disposed in the insertion port 6. The lid portion 9 is formed in such a size as to cover water in order to prevent water from entering the insertion holes 2 and 3 through the lid portion 9, for example. In the illustrated example, the lid portion 9 is made of metal and is formed in a substantially square shape that is slightly larger than the insertion port 6, and the bolts 9 a are tightened by using the inserts 9 b arranged at the four corner portions thereof. It is fixed to the insertion slot 6. Specifically, the segments 11 to 14 and 21 to 24 are fixed to the holes 52 formed around the insertion openings 6 via bolts 9a.

  Moreover, the 2nd penetration hole 3 is formed in a predetermined segment so that it may penetrate in the width direction of the precast concrete units 10 and 20. In the illustrated example, the second insertion holes 3 are formed in the A, C, D, E, G, and H segments 11, 13, 14, 21, 23, and 24. At both ends 5 in the width direction of the precast concrete units 10 and 20 arranged side by side in the width direction, there are formed insertion ports 6 that communicate with the second insertion holes 3 and into which the tension material is removably inserted. . The shape of the periphery of the insertion port 6 and the insertion port 6 is the same as that of the insertion port 6 formed to communicate with the first insertion hole 2.

  The two precast concrete units 10 and 20 arranged side by side in the width direction communicate with the second insertion hole 3, and a PC steel wire 8 as a tension material is detachably disposed. After the PC steel strand 8 is pulled, both end portions 8a thereof are fixed in the insertion port 6 with nuts 8a, thereby having prestress.

  In order to prevent water from entering the insertion holes 2 and 3 through the insertion hole 6, a metal lid portion 9 is formed in such a size as to cover the insertion opening 6. The member, shape, and the like around the lid portion 9 fixed to the insertion port 6 are the same as described above.

  As shown in FIG. 2, the first convex portion 31 or the first concave portion 32 is formed on each of the segments 11 to 14 and 21 to 24 on the surface facing the length direction of the precast concrete units 10 and 20. At the same time, the first concave portion 32 or the first convex portion 31 that fits into the first convex portion 31 or the first concave portion 32 is formed on the opposing surfaces of the adjacent segments. Further, as shown in FIG. 3, the precast concrete units 10 and 20 are formed with second protrusions 41 or second recesses 42 at appropriate intervals, and relative to adjacent precast concrete units 10 and 20. The second concave portion 42 or the second convex portion 41 that fits into the second convex portion 41 or the second concave portion 42 is formed on the facing surface. Below, with reference to FIGS. 8-16, the structure of each segment 11-14, 21-24 is demonstrated concretely.

  FIG. 8 is a perspective view of the A segment 11. A first recess 32 is formed in the A segment 11 on the surface facing the adjacent B segment 12. The 1st recessed part 32 is formed over the long side direction of the A segment 11, and an inclined surface is formed in the upper end and the lower end, respectively (the shape etc. of the 1st recessed part 32 formed in each segment hereafter) The same.) In the A segment 11, a second recess 42 is formed on the surface facing the E segment 21. The second recess 42 is formed over the short side direction of the A segment 11, and an inclined surface is formed at each of the upper end and the lower end thereof (hereinafter, the shape of the second recess 42 formed in each segment is The same.)

  A first insertion hole 2 is formed in the A segment 11 so as to penetrate in the short side direction. Three first insertion holes 2 are positioned approximately at the center in the vertical direction in the first recess 32, and three first insertion holes 2 are arranged in parallel in the long side direction of the A segment 11. The A segment 11 is a surface opposite to the surface on which the first recess 32 is formed, that is, the left end portion 4 of the first precast concrete unit 10 is communicated with each first insertion hole 2. Three insertion ports 6 are formed. The insertion port 6 has a larger diameter than the first insertion hole 2 and is formed in a substantially square shape (hereinafter, the shape of the first insertion hole 2 and the insertion port 6 formed in each segment is the same). .)

  A second insertion hole 3 is formed in the A segment 11 so as to penetrate in the long side direction. One second insertion hole 3 is formed below the second recess 42. The A segment 11 is a surface opposite to the surface on which the second concave portion 42 is formed, that is, the rear end portion 5 of the first precast concrete unit 10 is communicated with the second insertion hole. 6 is formed (hereinafter, the shape and the like of the second insertion hole 3 and the insertion port 6 formed in each segment are the same).

  On the upper surface of the A segment 11, suspension parts 51 for lifting the A segment 11 with a hoisting machine or the like are formed at two positions with appropriate intervals. Further, although not shown, a support part for supporting the temporary support column is also formed at an appropriate place. In addition, the suspension part 51 and the support part are formed in substantially the same manner on the B to E segments described below.

  9A is a plan sectional view of the A segment 11, and FIG. 9B is a side sectional view of the A segment 11. The A segment 11 is a reinforced concrete in which a rebar 53 assembled in a bowl shape is disposed, and is formed in a rectangular parallelepiped shape. The same applies to the B to H segments 12 to 14 and 21 to 24 described below, as well as the material and the saddle-shaped reinforcing bars 53 disposed therein.

  FIG. 10 is a perspective view of the B segment 12. In the B segment 12, a first convex portion 31 that fits into the first concave portion 32 is formed on the surface facing the A segment 11. The first convex portion 31 is formed over the long side direction of the B segment 12 so as to be closely fitted to the first concave portion 32, and faces the inclined surface of the first concave portion 32 at the upper end and the lower end thereof. (Hereinafter, the shape and the like of the first protrusions 31 formed in each segment are the same). This facilitates positioning and fitting during placement.

  On the other hand, a first recess 32 is formed in the B segment 12 on the surface facing the right C segment 13 or D segment 14. Further, the B segment 12 is formed with a second recess 42 similar to that formed in the A segment 11 on the surface facing the F segment 22. Further, a first insertion hole 2 is formed in the B segment 12 so as to penetrate in the short side direction. The first insertion holes 2 are formed at the same position and number as the first insertion holes 2 formed in the A segment 11.

  FIG. 11 is a perspective view of the C segment 13. In the C segment 13, a first convex portion 31 that fits into the first concave portion 32 of the B segment 12 is formed on the surface facing the left B segment 12. On the other hand, a first recess 32 is formed in the C segment 13 on the surface facing the right B segment 12. Further, a second recess 42 is formed in the C segment 13 on the surface facing the G segment 23. Further, a first insertion hole 2 is formed in the C segment 13 so as to penetrate in the short side direction. The first insertion holes 2 are formed at the same position and number as the first insertion holes 2 formed in the A segment 11. A second insertion hole 3 is formed in the C segment 13 so as to penetrate in the long side direction. One second insertion hole 3 is formed below the second recess 42. The C segment 13 is a surface opposite to the surface on which the second recess 42 is formed, that is, the rear end surface 5 of the first precast concrete unit 10 is communicated with the second insertion hole 3 and the insertion port 6 is formed.

  FIG. 12 is a perspective view of the D segment 14. In the D segment 14, a first convex portion 31 that fits into the first concave portion 32 of the B segment 12 is formed on a surface facing the adjacent B segment 12. Further, a second recess 42 is formed in the D segment 14 on the surface facing the H segment 24.

  The first insertion hole 2 is formed in the D segment 14 so as to penetrate in the short side direction. The first insertion holes 2 are formed at the same position and number as the first insertion holes 2 formed in the A segment 11. The D segment 14 is a surface opposite to the surface on which the first convex portion 31 is formed, and is inserted into the right end surface 4 of the first precast concrete unit 10 through the first insertion holes 2. Three 6 are formed.

  A second insertion hole 3 is formed in the D segment 14 so as to penetrate in the long side direction. One second insertion hole 3 is formed below the second recess 42. The D segment 14 is a surface opposite to the surface on which the second recess 42 is formed, that is, the rear end surface 5 of the first precast concrete unit 10 is communicated with the second insertion hole 3 and the insertion port 6 is formed.

  FIG. 13 is a perspective view of the E segment 21. In the E segment 21, a first recess 32 is formed on a surface facing the adjacent F segment 22. In the E segment 21, a second convex portion 41 is formed on a surface facing the A segment 11. The second convex portion 41 is formed over the short side direction of the E segment 21 so as to be closely fitted to the second concave portion 42, and the inclined surface that faces the inclined surface of the second concave portion 42 at the upper and lower ends thereof. (Hereinafter, all the shapes of the second convex portions 41 formed in each segment are the same). This facilitates positioning and fitting during placement.

  A first insertion hole 2 is formed in the E segment 21 so as to penetrate in the short side direction. The position and number of the first insertion holes 2 are the same as those of the A segment 11. The E segment 21 is the surface opposite to the surface on which the first recess 32 is formed, that is, the left end 4 of the second precast concrete unit 20 is communicated with the first insertion hole 6 through the insertion port 6. Are formed.

  Two insertion holes 3 are formed in the E segment 21 so as to communicate with the second insertion holes 3 formed in the A segment 11. The position and number of the second insertion holes 3 are the same as those of the A segment 11. The E segment 21 is a surface opposite to the surface on which the second convex portion 41 is formed, that is, the front end portion 5 of the second precast concrete unit 20 is communicated with the second insertion hole 3. The insertion port 6 is formed.

  FIG. 14 is a perspective view of the F segment 22. In the F segment 22, a first convex portion 31 that fits into the first concave portion 32 is formed on a surface facing the E segment 21 or the G segment 23 on the left side. On the other hand, a first recess 32 is formed in the F segment 22 on the surface facing the G segment 23 or H segment 24 adjacent to the right. A second convex portion 41 is formed on the F segment 22 on the surface facing the B segment 12. A first insertion hole 2 is formed in the F segment 22 so as to communicate with the first insertion hole 2 formed in the E segment 21.

  FIG. 15 is a perspective view of the G segment 23. In the G segment 23, a first convex portion 31 that fits into the first concave portion 32 of the F segment 22 is formed on a surface opposite to the left adjacent F segment 22. On the other hand, a first recess 32 is formed in the G segment 23 on the surface facing the right F segment 22. A second convex portion 41 is formed on the G segment 23 on the surface facing the C segment 13. A first insertion hole 2 is formed in the G segment 23 so as to penetrate in the short side direction. The first insertion hole 2 is formed at the same position as the first insertion hole 2 formed in the E segment 21. A second insertion hole 3 is formed in the G segment 23 so as to communicate with the second insertion hole 3 formed in the C segment 13. The G segment 23 is a surface opposite to the surface on which the second convex portion 41 is formed, that is, the front end portion 5 of the second precast concrete unit 20 is communicated with the second insertion hole 3. The insertion port 6 is formed.

  FIG. 16 is a perspective view of the H segment 24. In the H segment 24, a first convex portion 31 that fits into the first concave portion 32 of the F segment 22 is formed on a surface facing the adjacent F segment 22. The second segment 41 is formed on the H segment 24 on the surface facing the D segment 14.

  A first insertion hole 2 is formed in the H segment 24 so as to penetrate in the short side direction. The first insertion hole 2 is formed at the same position as the first insertion hole 2 formed in the E segment 21. The H segment 24 is inserted on the surface opposite to the surface on which the first convex portion 31 is formed, that is, on the right end 4 of the second precast concrete unit 20 so as to communicate with the first insertion hole 2. Three mouths 6 are formed.

  A second insertion hole 3 is formed in the H segment 24 so as to communicate with the second insertion hole 3 formed in the D segment 14. Further, the H segment 24 is a surface opposite to the surface where the second recess 42 is formed, that is, the front end portion 5 of the second precast concrete unit 20 is communicated with the second insertion hole 3. Thus, the insertion port 6 is formed.

  Next, the construction method of the foundation structure 1 of the temporary support column according to the present embodiment will be described in detail.

  (1) First, the precast concrete units 10 and 20 are divided into A to D and E to H segments 11 to 14 and 21 to 24 in advance in the length direction and molded. Manufacture of each segment 11-14, 21-24 is performed in a factory, a field site, etc.

  (2) Next, level the installation position. Leveling is done according to the installation position, such as excavating the space where work can be performed if necessary, or laying a dumping container or iron plate.

  (3) The A to H segments 11 to 14 and 21 to 24 are carried in from a factory or the like. In addition, necessary items such as PC steel wires 8 are carried in.

  (4) The carried A to H segments 11 to 14 and 21 to 24 are lifted by a bulletin board via a suspension unit 51 from a state of being mounted on the carry-in vehicle, and installed at the installation position. Specifically, the A to D segments 11 to 14 are sequentially connected to the first precast concrete unit 10 by fitting the first concave portion 32 and the first convex portion 31 formed on the opposing surfaces, respectively. Let Next, the E-H segments 21 to 24 are sequentially connected to the second precast concrete unit 20 by fitting the first concave portion 32 and the first convex portion 31 formed on the opposing surfaces, respectively. At this time, the 2nd convex part 41 formed in the EH segment 21-24 is fitted and arrange | positioned to the 2nd recessed part 42 formed in the AD segment 11-14. At the time of installation, the adjacent segments 11 to 14, 21 to 24 and the precast concrete units 10 and 20 are installed in a state where they can be separated from each other, and the segments 11 to 14, 21 to 24 are installed. Be careful to check the position, height, level, etc. The order of installing the segments may be anything.

  (5) Next, the tendon is inserted into the insertion holes 2 and 3 through the insertion port 6. Specifically, the PC steel wire 8 is removably inserted into the first insertion hole 2 in the length direction of the first and second precast concrete units 10 and 20. In the illustrated example, three PC steel strands 8 are inserted through each of the precast concrete units 10 and 20. And pulling the wire 8 from these PC steel, fixing the both ends 8a of the PC steel wire 8 with the nut 8b in the insertion port 6 formed in the both ends 4 of each precast concrete unit 10, 20, Prestress. Thereafter, the PC steel wire 8 is detachably inserted into the second insertion hole 3 in the width direction of the first and second precast concrete units 10 and 20. In the illustrated example, one PC steel strand 8 is inserted through each of the A and E segments 11 and 21, the C and G segments 13 and 23, and the D and H segments 14 and 24. Then, as described above, predetermined prestress is applied to the PC steel wire 8, and both end portions 8 a of the PC steel wire 8 are fixed in the insertion port 6 with nuts 8 b. At this time, the tension material may not be the stranded wire 8 of PC steel. For example, another PC steel wire, a conventionally known PC steel rod, carbon FRP, or the like may be used.

  (6) The lid 9 is fixed to each insertion port 6 with a bolt 9a.

  (7) Finally, after confirming the shape and position of the foundation structure 1 of the installed temporary column, the foundation of the temporary column is placed on the upper surface of the connected precast concrete units 10 and 20 in the length direction, respectively. Install one by one through the support. Then, a temporary support column is installed on the base.

  (8) At the time of dismantling, after dismantling and removing the temporary support column and base, the lid 9 of the insertion port 6 is removed, and the nuts 8b at both ends 8a of the wires 8 are removed from each PC steel to remove prestress. It is loaded and pulled out while winding the wire 8 from the PC steel.

  (9) At this time, the precast concrete units 10 and 20 are separated into the segments 11 to 14 and 21 to 24 so as to be diverted. Here, “separated so as to be divertable” means that the segment is separated into the original state without being destroyed, and does not necessarily require reuse.

  (10) Unload the segments 11 to 14 and 21 to 24 from the installation positions and store them in a storage place for reuse. Then, the installation position is returned to the current state.

  In the temporary strut base structure 1 and the construction method thereof according to the present embodiment, the precast concrete units 10 and 20 are divided into segments 11 to 14 and 21 to 24 in advance, as described above. Even after the temporary support column is dismantled, it is not necessary to destroy and remove, and the amount of waste can be reduced. For this reason, CO2 is reduced, and noise on site is also reduced, which has an environmental effect. In addition, it is possible to reduce the labor and time required for construction and dismantling, and the overall construction cost can be reduced. In addition, it is possible to ensure a desired strength by applying prestress during installation.

  In addition, by connecting the segments 11-14, 21-24 previously molded in factory production etc. at the site, and applying prestress by inserting the tension material, the prestress is released after dismantling the temporary struts, If the tendon is pulled out, each segment 11-14, 21-24 can maintain the original state. As a result, it can be reused. In particular, the number of segments and the number of precast concrete units can be freely set according to the size of the installation position, so that it is easy to reuse and further cost reduction can be realized.

  Even if it is the foundation structure 1 of the temporary support | pillar in which accuracy is requested | required by manufacturing each segment 11-14, 21-24 in a factory, uniform quality can be maintained.

  In addition, by producing the segments 11 to 14 and 21 to 24 at the factory, space for placing materials and scraps after dismantling is not necessary, and work efficiency is increased, compared to the above-described background technology. It becomes possible.

  Furthermore, since the 1st recessed part 32 and the 1st convex part 31 fitted to this are formed in each segment 11-14, 21-24, each segment 11-14, 21-24 is connected, precast concrete If prestress is applied to the units 10 and 20, the first concave portion 32 and the first convex portion 31 are brought into close contact with each other, so that a load is applied to the precast concrete units 10 and 20 integrally, and an integral shearing force can be transmitted. It becomes like this. Further, when the plurality of precast concrete units 10 and 20 are connected, the second concave portion 42 and the second convex portion 41 are in close contact with each other and prestress is applied, so that the plurality of precast concrete units 10 and 20 are integrated with each other. As a result, a load is applied to the body and an integral shearing force can be transmitted.

  In this embodiment, the 1st convex part 31 and the 1st recessed part 32 are formed over the long side direction of each segment 1-14, 21-24, and an inclined surface forms in the upper end and lower end, respectively. It had been. However, the shape of the first convex portion 31 and the first concave portion 32 is not limited thereto, and may be any shape that can be fitted while being in close contact with each other. The same applies to the second convex portion 41 and the second concave portion 42.

  In this embodiment, since the stress from which the lower end surface in the width direction opens left and right due to the load from the temporary support column is applied from the shape of the foundation, the tension material on the length direction side of the precast concrete units 10 and 20 is The tension material on the side in the width direction is inserted below the center in the vertical direction. However, the vertical position at the time of disposing the tension material is not limited to this, and the direction side that is easily broken by the direction of the load applied from the temporary support column is disposed at the lower position so that the segment on the installation surface side is not broken. It can be changed as appropriate.

  In the present embodiment, the two precast concrete units 10 and 20 are arranged side by side. However, the present invention is not limited to this, and there may be one precast concrete unit or three or more precast concrete units. This can be appropriately changed according to the size of the installation position. Further, the number of segments constituting the precast concrete unit is not limited to that of the present embodiment.

  In the present embodiment, the lid portion 9 is made of metal, and is detachably fixed to the insertion port with a bolt 9a. However, the lid portion 9 does not have to be detachable. For example, as shown in FIGS. 17 and 18, a method such as fixing with a mortar 60 that is a conventionally known technique may be used. However, in this case, it is necessary to take measures such as tearing the mortar 60 in the insertion opening 6.

  In the present embodiment, mortar, grout or the like was not injected into the joint surfaces of the segments 11 to 14 and 21 to 24 and the first and second insertion holes 2 and 3. For this reason, a waterproof material is attached to the joint surface of each segment 11-14, 21-24, or a waterproof material is apply | coated around the 1st and 2nd insertion holes 2 and 3 according to a situation for rust prevention etc. May be. Further, a fixing material such as grout may be injected into the first and second insertion holes 2 and 3 in order to prevent rusting and loosening of the tension material. However, in this case, it is difficult to remove the tendon.

DESCRIPTION OF SYMBOLS 1 Foundation structure of temporary support | pillar 2 1st insertion hole 3 2nd insertion hole 6 Insertion opening 7 Grit muscle 8 PC steel strand 9 Lid part 9a Bolt 9b Insert 10 1st precast concrete unit 11 A segment 12 B segment 13 C segment 14 D segment 20 2nd precast concrete unit 21 E segment 22 F segment 23 G segment 24 H segment 31 1st convex part 32 1st recessed part 41 2nd convex part 42 2nd recessed part

Claims (6)

It is a foundation structure of a temporary support using a precast concrete unit,
The precast concrete unit has a plurality of segments that are preliminarily divided and molded in the length direction, and is closely arranged in a separable state.
In the precast concrete unit, in the length direction, a first insertion hole formed in each of the segments is communicated, and a tension material having a predetermined prestress is detachably disposed.
The segment has a first convex portion or a first concave portion formed on the surface facing the length direction of the precast concrete unit, and the first convex portion is formed on the opposing surface of the adjacent segment. Or the 1st recessed part or 1st convex part fitted to this 1st recessed part is formed, The foundation structure of the temporary support | pillar characterized by the above-mentioned. The precast concrete units are juxtaposed in the width direction in a state where at least two or more can be separated,
In these precast concrete units, in the width direction, the second insertion holes formed in these segments are communicated, and a tension material having a predetermined prestress is detachably disposed.
In the segment, a second convex portion or a second concave portion is formed on the surface facing the width direction of the precast concrete unit, and the second convex portion is formed on the opposing surface of the adjacent precast concrete unit. The foundation structure of the temporary support | pillar of Claim 1 in which the 2nd recessed part or 2nd convex part fitted to a part or this 2nd recessed part is formed.   The foundation structure of the temporary support column according to claim 1 or 2, wherein a lid portion that seals the first insertion hole or the second insertion hole from the outside is detachably disposed. After precast concrete unit is divided into segments in advance in the length direction,
In the installation position, the plurality of segments are connected in the form of the precast concrete unit in a separable state with the opposing surfaces in close contact with each other,
In the precast concrete unit, in the length direction, the first insertion holes respectively formed in these segments are communicated, and the tension material is removably inserted,
Apply a predetermined prestress to the tendon, and integrate the precast concrete unit,
A method for constructing a foundation structure for a temporary support, wherein a temporary support is installed on the precast concrete unit. At the installation position, the precast concrete units are arranged in parallel in at least two or more in the width direction in a state where they can be separated while bringing the opposing surfaces into close contact with each other.
In these precast concrete units, in the width direction, the second insertion hole formed in the segment is communicated, and the tension material is removably inserted,
A predetermined prestress is applied to the tendon, and the plurality of precast concrete units arranged side by side are integrated,
The temporary strut foundation construction method according to claim 4, wherein temporary struts are installed on the plurality of precast concrete units. After dismantling the temporary struts installed on the one or more precast concrete units,
After unloading the prestress of the tendon, the tendon is removed,
6. The method for constructing a foundation structure of a temporary support column according to claim 4, wherein the one or a plurality of precast concrete units are separated so as to be divertable to the segment.

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