JP5827158B2 - Underground structure - Google Patents

Description

  The present invention relates to an underground structure.

  In the basement of subway platforms and buildings formed in underground spaces, it is required to provide a middle pillar with a small cross section in order to make effective use of the space. However, since the axial proof stress obtained with the middle pillar having a reduced cross section is reduced, it is required to make the middle pillar as small as possible while ensuring the required axial proof strength.

  Conventionally, as a central pillar of this type of underground structure, a reinforced concrete structure or a concrete-filled steel pipe structure is known. The middle column of the reinforced concrete structure is made up of reinforced concrete. In the concrete-filled steel pipe structure, a hollow steel pipe is filled with concrete, and this steel pipe is erected to form a middle pillar.

  However, in a reinforced concrete structure, when it is used as a middle column of an underground structure subjected to high axial compressive stress, if bending deformation occurs in the middle column during an earthquake, it may be caused by compressive failure of the concrete or buckling of the axial rebar. There was a problem that the yield strength was likely to be lowered and it was difficult to ensure sufficient deformation performance. Furthermore, there is a problem that the bar arrangement work becomes difficult because the bar arrangement structure of the joint with the upper and lower beams becomes complicated when the middle column is used.

  On the other hand, in the concrete-filled steel pipe structure, the upper and lower beams have a steel structure or a steel reinforced concrete structure from the viewpoint of the proof stress and the workability of the joint with the middle column. Further, when joining the middle column of a concrete structure-filled steel pipe and a beam of reinforced concrete structure, there is a problem that a work such as making a hole in the steel pipe is necessary, and the work of arranging the bars is troublesome. Furthermore, the middle column main body has a problem that durability is lowered because the steel material is exposed on the surface.

  In contrast to these techniques, there is a steel pipe column for a structure that is a middle column combining a concrete-filled steel pipe structure and a cast iron bearing plate (see, for example, Patent Document 1). This structural steel pipe column has a structure in which cast iron widened bearing plates are arranged at the upper and lower ends of a concrete-filled steel pipe and are erected between upper and lower beams.

JP-A-2-183039

  Since the steel pipe column for a structure disclosed in Patent Document 1 uses a concrete-filled steel pipe, it has a high axial load-bearing performance and a high earthquake deformation performance, and enables RC members to be arranged on the upper and lower beams. It is something that can be done. Furthermore, because it is a structure that only fills high-strength mortar between the bearing concrete and the bearing plate without fixing the upper and lower ends, there is no need for complicated reinforcement between the middle column and the beam. There are advantages.

  However, the structural steel pipe column disclosed in Patent Document 1 has a structure in which the steel pipe is exposed, like the concrete-filled steel pipe structure. For this reason, the problem of the concrete-filled steel pipe structure that the exposed steel pipe is highly likely to corrode and has low durability has not been solved.

  Furthermore, the member using steel materials, such as a steel pipe and a cast iron bearing plate, has the problem that it is expensive compared with the member made from a reinforced concrete.

  Therefore, the problem of the present invention is that it has high axial strength performance and seismic performance, and can exhibit high durability while requiring no special restrictions on the upper and lower beams, and can be manufactured at low cost. It is to provide an underground structure that can be used.

An underground structure according to the present invention that has solved the above problems is an underground structure including a middle pillar member that connects beam members arranged in an underground space, and the middle pillar member is a middle pillar body made of reinforced concrete. And a pair of bearing plates arranged at both ends of the middle column main body , each of the bearing plates is fixed to the beam member, and the middle column body is supported by the bearing plate. between the plates, along the longitudinal direction of the center post body has a plurality of reinforcing bars are Haisuji, the ends of a plurality of reinforcing bars, binding structure to improve the lateral cohesion of the reinforcing bars are provided, bundling structure, a plurality The ends of the reinforcing bars are converged and formed at a position corresponding to the central portion of the cross section of the middle column main body in the bearing plate .
The bundling structure includes high-strength spiral bars provided around the ends of a plurality of reinforcing bars in the bearing plate, and high-strength concrete in which the ends of the plurality of reinforcing bars are embedded inside the high-strength spiral bars. You may make it have.

  The underground structure according to the present invention includes a bearing plate fixed to the beam member and a middle column main body supported by the bearing plate, and extends along the longitudinal direction of the middle column main body between the pair of bearing plates. A binding structure for increasing the lateral binding force of the reinforcing bars is provided at the ends of the plurality of reinforcing bars. By providing this binding structure, the lateral binding force of the reinforcing bars is increased. For this reason, the middle column member can exhibit high axial strength performance and seismic performance. Furthermore, the middle pillar body is made of reinforced concrete. For this reason, since it can be made not to be in the state where steel materials are exposed to the surface, high durability can be exhibited. Moreover, the middle column body is supported by the bearing plate. For this reason, since it is not necessary to extend the reinforcing bar of the middle column main body to the beam member, it is possible to prevent the upper and lower beams from requiring special restrictions. Furthermore, since the middle column body and the bearing plate are made of reinforced concrete, the middle column body can be inexpensive compared to the case where the bearing plate is made of steel.

Further, the bundling structure includes a high-strength spiral bar provided around the ends of the plurality of reinforcing bars in the bearing plate, and a height for embedding the ends of the plurality of reinforcing bars inside the high-strength spiral bar. You may make it have strong concrete.

  In addition, the outer periphery of the beam member connecting surface that is in contact with the beam member in the bearing plate is greater than the outer periphery of the middle column body contact surface that is in contact with the middle column body in the bearing plate or the cross section near the contact surface. Can also be made larger.

  In this way, the outer periphery of the beam member connection surface of the bearing plate is larger than the outer periphery of the cross section in the vicinity of the middle column main body contact surface, so that the maximum acting between the bearing plate and the beam member is achieved. Bending stress can be reduced. For this reason, it is possible to prevent the support plate from floating from the beam member.

  Further, a sealing material can be interposed between the bearing plate and the middle column member.

  Thus, since the sealing material is interposed between the bearing plate and the middle column member, it is possible to prevent water from entering the middle column member from between the bearing plate and the middle column member. For this reason, rust prevention of steel materials, such as a reinforcing bar provided inside the middle pillar member, can be aimed at. Here, as the sealing material, for example, rubber such as silicone rubber, EPDM rubber (ethylene propylene rubber), and butyl rubber can be suitably used.

  And at least one of the upper end part and lower end part of a middle pillar main body can be reinforced with the steel pipe or the resin pipe.

  In this way, at least one of the upper end and the lower end of the middle column body is reinforced by a steel pipe or a resin tube, thereby suppressing buckling of the axial rebar in the middle column body and compressive failure of the internal concrete. can do. Therefore, it is possible to further increase the axial strength and the deformation performance during an earthquake.

  According to the underground structure according to the present invention, it has high axial strength performance and seismic performance, and can exhibit high durability while requiring no special restrictions on the upper and lower beams, and further manufactured at low cost. can do.

It is a figure which shows the outline | summary of the underground structure which concerns on embodiment of this invention. (A) is a sectional side view of the middle pillar, (b) is a front sectional view of the middle pillar. It is the III-III sectional view taken on the line of Fig.2 (a). It is a sectional side view of a bearing plate. It is the VV sectional view taken on the line of FIG. It is process drawing which shows the process of manufacturing a middle pillar. FIG. 7 is a process diagram illustrating a process following the process in FIG. 6. (A)-(c) is a figure which shows the outline | summary at the time of standing up a center pillar.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In each embodiment, portions having the same function are denoted by the same reference numerals, and redundant description may be omitted.

  FIG. 1 is a diagram showing an outline of an underground structure according to an embodiment of the present invention. As shown in FIG. 1, the underground structure M according to the present embodiment is provided in the underground space, is a subway platform, and is provided with a plurality of middle pillars H that are middle pillar members of the present invention. . In addition, in the underground structure M, bearing concrete B serving as a beam member is provided in the lower floor and the ceiling, and the middle pillar H is composed of the bearing concrete B in the lower floor and the bearing concrete B in the ceiling. It is erected in between and joined with bearing concrete B. Above the underground structure M, various underground buried objects R and the like are buried.

  2A is a side sectional view of the middle pillar, FIG. 2B is a front sectional view of the middle pillar, and FIG. 3 is a sectional view taken along line III-III in FIG. As shown in FIG. 2, the middle column H includes a middle column body 1 and a pair of bearing plates 2 and 3, and an upper bearing plate 2 and a lower column are provided at both ends of the middle column body 1. A pressure plate 3 is provided. The bearing plates 2 and 3 are fixed laterally with respect to the bearing concrete B by a frictional force generated by a vertical axial force acting between the bearing concrete B and the bearing plates 2 and 3. ing.

  The middle column main body 1 has a reinforced concrete structure and is a PCa (precast concrete) column having a high rebar ratio. A plurality of reinforcing bars 11 along the height direction are arranged on the middle column main body 1. Further, as shown in FIG. 3, an upper mortar filling joint 12 is attached to the upper ends of the reinforcing bars 11. Further, a lower mortar filling joint 13 is attached to the lower end of the reinforcing bar 11. The plurality of reinforcing bars 11 are arranged along the longitudinal direction of the middle column main body 1 between the bearing plates 2 and 3.

  Further, as shown in FIGS. 2A and 2B, the middle pillar H has a wide structure and has a cross-sectional shape or a substantially rectangular shape. When the middle pillar H is installed in the underground structure M, it is preferable that the wide surface is arranged along the rail of the track laid on the side of the platform.

  The upper bearing plate 2 and the lower bearing plate 3 have the same configuration, and both are arranged in a form in which the top and bottom are repeated. The structure will be described using the upper support plate 2. As shown in FIGS. 4 and 5, the upper bearing plate 2 includes a bearing plate body 21 having a substantially trapezoidal shape with a short side and a long side in cross-sectional shape. The taper which expands toward the bearing concrete side from the middle pillar main body 1 side is attached. For this reason, in the upper bearing plate 2, the outer periphery of the beam member connection surface that comes into contact with the bearing concrete B is larger than the outer circumference of the middle column body contact surface that comes into contact with the middle column body 1. Has been. Further, a bottom plate 22 is provided inside the bearing plate main body 21. The bottom plate 22 is made of a steel plate, and is disposed along a substantially horizontal plane.

  The middle pillar body 1 is disposed on the short side of the bearing plate body 21 with respect to the bottom plate 22. A hole portion 23 having a substantially cylindrical shape is formed on a surface of the bearing plate main body 21 facing the middle column main body 1, and the hole portion 23 is provided with a high-strength spiral line 24 that is a lateral restraint line. Yes. Further, a plurality of axial rebars 25 are disposed inside the high-strength spiral bars 24. The number of the axial reinforcing bars 25 is the same as the number of the reinforcing bars 11 provided in the middle column main body 1. The hole 23 constitutes a reinforcing bar accommodation hole of the present invention. In addition, reinforcing bars are arranged inside the high-strength spiral bars 24 and filled with concrete or mortar. Reinforcing bars and concrete arranged inside the high-strength spiral bars 24 are integrated with the middle column main body 1 and constitute end portions of the middle columns. For this reason, the cross section of the middle column end is smaller than the central portion in the longitudinal direction of the middle column main body 1.

  Furthermore, the outer periphery of the surface of the bearing plate main body 21 that comes into contact with the bearing concrete B is made larger than the outer periphery of the hole 23. The surface in contact with the bearing concrete B in the bearing plate main body 21 is the beam member connecting surface of the present invention. Further, the inner side surface of the hole portion 23 serves as a middle column contact surface of the present invention, and the outer periphery of the hole portion 23 serves as the outer periphery of the middle column contact surface.

  The axial rebar 25 extends along the height direction of the bearing plate main body 21 and is arranged. These axial reinforcing bars 25 are formed in a bent shape in which the end on the side of the bearing plate main body 21 is converged to the center of the hole 23, and the tip thereof is accommodated in the hole 23. . In addition, a lateral restraint reinforcing bar 26 that is a lateral restraint is arranged at the end of the axial rebar 25 on the side of the bearing plate main body 21. A plurality of axial rebars 25 are bundled by the lateral restraint reinforcing bars 26.

  Furthermore, a widened hole 27 having a taper that increases in diameter as it goes to the short side of the bearing plate main body 21 is formed on the short side of the bearing plate main body 21 in the hole 23. This taper is formed at least on the short side of the bearing plate main body 21. Further, for example, the widened hole 27 may be formed in a trumpet shape so that a taper is formed in all directions. By this widening hole 27, it is possible to allow the bending deformation behavior of the end portion of the middle column main body 1 during an earthquake or the like, and to control the curvature of the bending deformation of the end portion of the middle column main body 1. Note that the surface of the widening hole 27 that is not in contact with the middle column body 1 is a contact surface vicinity cross section in the present invention.

  Further, the widened hole 27 is provided with an inner rubber mold 28. The inner rubber mold 28 is disposed around the high-strength spiral line 24, and the outer shape thereof is substantially the same as the inner shape of the widening hole 27. The inner rubber mold 28 may be used in an embedded state, or may be removed from the inner rubber mold 28 merely as a gap. Examples of the material constituting the inner rubber mold 28 include rubber, silicone, paraffin, and clay.

  An intermediate concrete member 29 that covers the axial rebar 25 and the lateral restraint rebar 26 is provided on the short side of the bearing plate main body 21. Further, a gap is formed between the bearing plate main body 21 and the intermediate concrete member 29. A sealing material 30 having water tightness and hardly transmitting stress when deformed by an earthquake is disposed in the gap. The sealing material 30 plays a role of rust prevention of internal steel materials (spiral rebar, axial rebar, steel pipe). Furthermore, the material constituting the sealing material 30 is preferably a non-combustible material that does not easily burn in the event of a fire.

  Furthermore, as shown in FIG. 5, the hole 23 formed in the bearing plate main body 21 is filled with high-strength concrete or high-strength mortar 31. A reinforcing bar 32 is housed inside the bearing plate main body 21. By filling the hole 23 with the high-strength concrete 31, the lateral binding force of the axial rebar 25 accommodated in the hole 23 is enhanced. The high-strength spiral muscle 24 and the high-strength concrete 31 in the hole portion 23 constitute the binding structure of the present invention.

  In the underground structure M according to the present embodiment having the above configuration, the end portions of the plurality of reinforcing bars 11 arranged along the longitudinal direction of the middle column main body 1 between the pair of bearing plates 2 and 3. In addition, a hole 23 serving as a bundling structure that enhances the lateral bundling force of the reinforcing bar 11 and a high-strength spiral bar 24 and a high-strength concrete 31 provided in the hole 23 are provided. For this reason, in the middle column H, the lateral binding force of the reinforcing bars 11 is increased through the axial rebar 25, so that the middle column H can exhibit high axial strength performance and seismic performance.

  Further, a lateral restraint reinforcing bar 26 is provided at an end of the axial reinforcing bar 25. By providing the laterally restrained reinforcing bars 26, the buckling of the axial reinforcing bars 25 can be suppressed. Further, the axial rebar 25 includes an arc constraining portion 23A above the hole 23 corresponding to the widening hole 27 and a linear constraining portion 23B below the hole 23 in the hole 23 formed in the bearing plate main body 21. It is restrained by. For this reason, buckling of the axial rebar 25 is further suppressed.

  In addition, since the middle column main body 1 is made of reinforced concrete, it is possible to prevent the steel material from being exposed on the surface, so that high durability can be exhibited. Furthermore, since the middle column main body 1 is made of reinforced concrete, it can be made cheaper than the case where the middle column main body 1 is made of steel.

  Further, the ends of the plurality of reinforcing bars arranged in the bearing plates 2 and 3 are formed to converge at the center of the cross section of the middle column main body 1, and the middle column end in the middle column main body 1 is the middle column. The cross section is made smaller than the central part. For this reason, the bending moment which arises in a middle pillar edge part can be made small. In addition, since the bending moment generated between the end of the middle column and the bearing plate 2 and the bending moment generated between the bearing plate 2 and the bearing concrete B are in a proportional relationship, the bending generated at the end of the middle column. By reducing the moment, the bending moment affecting the bearing concrete B can be reduced. As a result, the bending compressive stress acting on the bearing concrete during an earthquake can be reduced. Therefore, compression failure of the bearing concrete can be prevented.

  However, if the cross section of the end portion of the middle column is made small, the concrete is apt to be fractured and buckling of the reinforcing bars 11 extending in the axial direction of the middle column main body 1 is likely to occur. In this respect, a binding structure for increasing the lateral binding force is formed at the end of the reinforcing bar extending in the axial direction of the middle column main body 1, and a high-strength spiral bar 24 and a laterally restrained reinforcing bar 26 are provided. By this lateral binding force, it is possible to prevent the concrete from being compressed and buckling of the axial rebar 25 extending in the axial direction of the middle column body 1. As a result, high shaft strength performance and seismic performance can be exhibited.

  In particular, the amount of rebar can be increased by using the high-strength spiral bars 24 as a binding structure that enhances the lateral binding force of the reinforcing bars extending in the axial direction of the middle column main body 1. For this reason, the binding force in the lateral direction of the reinforcing bar extending in the axial direction of the middle column main body 1 can be increased more suitably. For example, even if a large strain occurs, the compressive stress is not greatly reduced. can do.

  Further, in the underground structure M according to the present embodiment, a widening hole 27 having a taper is formed on the short side of the bearing plate main body 21. For example, when a large bending moment is applied to the middle column body 1, plastic deformation of the bending deformation of the middle column end member locally occurs due to the yield of the reinforcing bar 11 at the end of the middle column.

  Since the widened hole 27 is provided in the point bearing plate main body 21, the end of the middle column is allowed to swing during an earthquake or the like, so that the seismic performance can be further improved. Further, the widened hole 27 is provided with an inner rubber mold 28 that softly follows the air gap or seismic deformation. For this reason, the rocking | displacement displacement which arises when the high intensity | strength spiral muscle 24 rock | fluctuates can be absorbed suitably.

  In addition, the outer periphery of the beam member connection surface in contact with the bearing concrete B in the bearing plates 2 and 3 is more than the outer periphery of the hole 23 in contact with the middle column main body 1 in the bearing plates 2 and 3. Has also been enlarged. In this way, by making the outer periphery of the beam member connection surface larger than the outer periphery of the middle column body contact surface and making the cross section of the beam member connection surface larger than the cross section of the middle column body contact surface, the bearing plates 2, 3 And the maximum bending stress between the bearing concrete B can be reduced. For this reason, the maximum vertical direction stress which arises in the bearing concrete B can be suppressed as much as possible.

  Furthermore, the end of the axial rebar 25 is formed to converge toward the center of the cross section of the middle column main body 1. For this reason, the compression failure of the internal concrete in the middle pillar H can be suppressed, and the shaft strength and the deformation performance during earthquake can be further enhanced. In addition, the end of the axial rebar 25 is accommodated in the hole 23 in the bearing plate main body 21. For this reason, the shift | offset | difference to the horizontal direction of the center pillar main body 1 with respect to the bearing plates 2 and 3 can be suppressed. Therefore, a stable bending behavior at the time of an earthquake can be performed at the middle column end.

  In addition, since the gap is formed between the bearing plate main body 21 and the intermediate concrete member 29, the center column end portion is allowed to swing with respect to the bearing plate main body 21, so that the seismic performance can be further improved. it can. In addition, since the sealing material 30 is filled in the gap, it is possible to prevent water from entering the middle column body 1 from between the bearing plate main body 21 and the intermediate concrete member 29. For this reason, the rust prevention of steel materials, such as a spiral reinforcement provided in the inner side of the center pillar main body 1, an axial rebar, and a steel pipe, can be aimed at.

Furthermore, it is preferable to use the high-strength spiral muscle 24 as the lateral restraint muscle because the axial rebar ratio can be increased. Here, the axial rebar ratio refers to the ratio of the cross-sectional area of the rebar to the cross-sectional area in the cross section perpendicular to the axial direction of the middle column body 1. In order to have a high axial rebar ratio, for example, 30% or more, or even 40% or more, the high-strength spiral bars 24 having a yield point of 1275 N / mm ² or more are wound with no gaps or at a very small interval. do it.

  Further, the widening hole 27 outside the high-strength spiral muscle 24 forms an arc constraining arc portion 23A, and the lower portion of the hole 23 forms a linear constraining portion 23B. For this reason, when the high-strength spiral muscle 24 is bent and deformed, the high-strength spiral muscle 24 is restrained. Therefore, the deformation performance required for the underground structure can be realized even under ultra-high compressive stress.

  On the other hand, in the middle pillar H according to the present embodiment, the ends of the reinforcing bars 11 in the middle pillar body 1 are arranged on the bearing plates 2 and 3 and are not fixed to the bearing concrete B. . For this reason, the complicated reinforcement structure at the time of fixing the reinforcing bar 11 in the middle column H to the bearing concrete B can be eliminated. Further, the middle column body 1 is supported by the bearing plates 2 and 3. For this reason, since it is not necessary to extend the reinforcing bar 11 of the middle column main body 1 to the bearing concrete B, it becomes an up-and-down beam and it can be made not to require special restrictions for the bearing concrete B.

  Next, the construction procedure of the underground structure M according to this embodiment will be described. In the underground structure according to the present embodiment, the precast middle pillar body 1 and the bearing plates 2 and 3 are used. The middle column main body 1 and the bearing plates 2 and 3 are both made of precast, manufactured in a factory or the like, and carried into the construction site of the underground structure M.

  The middle column main body 1 attaches the reinforcing bar 11 and then attaches the mortar filling joints 12 and 13 to both ends of the reinforcing bar 11. Thereafter, concrete is provided around the reinforcing bars 11 to form the middle column main body 1. The upper support plate 2 is manufactured by the following manufacturing procedure. FIG. 6 is a process diagram showing the manufacturing procedure of the upper support plate.

  As shown in FIG. 6A, when manufacturing the upper support plate, the high-strength spiral muscle 24 is fixed to the bottom plate 22. Next, the lateral restraint reinforcing bar 26 is arranged on the side portion of the axial reinforcing bar 25. Subsequently, the axial reinforcing bar 25 is accommodated in a state where it is disposed at a predetermined position inside the high-strength spiral bar 24. Thereafter, a mold frame is arranged outside the high-strength spiral muscle 24, the concrete 31 is filled in the mold frame, and cured for a predetermined period, whereby the middle column end portion is manufactured inside the high-strength spiral muscle 24. Moreover, it can replace with the concrete 31 and can also be filled with mortar. Then, as shown in FIG. 6B, an inner rubber mold 28 is provided at a substantially central portion in the longitudinal direction of the high-strength spiral muscle 24.

  After that, as shown in FIG. 6C, the first mold X <b> 1 for pouring the concrete for manufacturing the bearing plate main body 21 is attached around the high-strength spiral muscle 24. And as shown in FIG.6 (d), concrete is poured into the 1st mold X1, and the bearing plate main body 21 is manufactured by curing for a predetermined period.

  At this time, a hole 23 shown in FIG. 4 is formed in the bearing plate main body 21 by the high-strength spiral stripes 24, and a widening hole 27 shown in FIG. 4 is formed by the inner rubber mold 28. Further, the inner rubber mold 28 is interposed in the widening hole 27. At this time, the inner rubber mold 28 can be removed.

  Then, the mold X1 is removed, and as shown in FIG. 7A, the bearing plate main body 21 is rotated by 90 degrees so that the axial rebar 25 is oriented in the horizontal direction. Thereafter, as shown in FIG. 7B, the second formwork X <b> 2 is installed around the lateral restraint reinforcing bar 26 at the end of the axial reinforcing bar 25.

  And after pouring concrete into the 2nd formwork X2, curing for a predetermined time, the intermediate | middle concrete member 29 is manufactured as shown in FIG.7 (c) by removing the 2nd formwork X2. Thereafter, the non-combustible rubber 30 is filled in the gap between the intermediate concrete member 29 and the bearing plate main body 21 to produce the upper bearing plate 2 shown in FIG. The non-combustible rubber 30 is manufactured by filling the gap between the intermediate concrete member 29 and the bearing plate main body 21. In addition, a non-combustible rubber 30 grounded in advance in a plate shape is grounded at a corresponding position of the mold X1, and the bearing plate is used. The concrete of the main body 21 can be placed and disposed in the gap between the intermediate concrete member 29 and the bearing plate main body 21. Alternatively, the intermediate concrete member 29 can be placed and placed in a gap between the intermediate concrete member 29 and the bearing plate main body 21 by being installed at a corresponding portion of the second formwork X2.

  The middle column main body 1 and the upper and lower bearing plates 2 and 3 manufactured in this way are installed in the underground structure M using a small crane CS as shown in FIG. Specifically, the lower support plate 3 is placed on the support concrete B serving as the lower beam. At this time, the lower bearing plate 3 is fixed to the bearing concrete B by an anchor (not shown). Further, the small crane CS can be accommodated in the underground structure M, and the middle pillar H can be attached in the underground structure M.

  Next, the middle column body 1 is lifted by the small crane CS, and the middle column body 1 is arranged above the lower support plate 3. Then, the lower mortar filling joint 13 provided in the middle column body 1 is connected to the axial reinforcing bar 25 in the lower bearing plate 3, and the middle column body 1 is integrated with the lower bearing plate 3. At this time, the reinforcing bar 11 in the middle column main body 1 is in a state of being continuous with the axial reinforcing bar 25 in the lower support plate 3.

  Then, the upper support plate 2 is lifted by the small crane CS. Thereafter, the upper mortar filling joint 12 in the middle column body 1 and the axial rebar 25 in the upper column pressure plate 2 are connected, and the upper column plate 2 is integrated with the middle column body 1. At this time, the reinforcing bar 11 in the middle column main body 1 is in a state of being continuous with the axial reinforcing bar 25 in the upper support plate 2. Thereafter, bearing concrete B serving as an upper beam is provided, and the middle pillar H is constructed. Thus, the middle pillar H according to the present embodiment is manufactured using the precast middle pillar body 1 and the bearing plates 2 and 3.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the middle column main body 1 is made of precast concrete, and any of them has a form in which concrete is exposed on the entire outer surface. On the other hand, it can also be set as the aspect by which at least one of the upper end part and lower end part of the center pillar main body 1 is reinforced with the steel pipe or the resin pipe. By suppressing at least one of the upper end portion and the lower end portion of the middle column body 1 with a steel pipe or a resin tube, the buckling of the axial rebar in the middle column body 1 and the compression failure of the internal concrete are suppressed. Can do. Therefore, it is possible to further increase the axial strength and the deformation performance during an earthquake.

  Moreover, in the said embodiment, although it is set as the precast concrete which is a different body from the middle column main body 1 and the bearing plates 2, 3, the precast concrete member with which the middle column main body and the bearing plate were integrated, You can also When an integrated middle column made of a precast concrete member in which the middle column main body and the bearing plate are integrated is installed in an underground structure, as shown in FIG. The integrated middle column 5 can be installed by hanging from the ground with the crane CB and hanging to the construction area of the underground structure M.

  Or as shown in FIG.8 (c), it can also be set as the aspect which conveys the integrated middle pillar 5 with the forklift F, and installs it in the underground structure M. FIG. When installing the middle pillar H or the integrated middle pillar 5, there are cases where work from the ground is possible and impossible. When the work from the ground is possible, the work using the large crane CB as shown in FIG. 8B is possible, and when the work from the ground is impossible, the works shown in FIGS. The work using the small crane CS and forklift F shown in FIG.

DESCRIPTION OF SYMBOLS 1 ... Middle pillar main body 2 ... Upper bearing plate 3 ... Lower bearing plate 5 ... Integrated middle column 11 ... Reinforcement 12 ... Upper mortar filling joint 13 ... Lower mortar filling joint 21 ... Bearing plate body 22 ... Bottom plate 23 ... Hole 23A ... Arc constraining part 23B ... Linear constraining part 24 ... High-strength spiral bar 25 ... Axial reinforcing bar 26 ... Lateral constraining bar 27 ... Widening hole 28 ... Inside rubber mold (or gap)
29 ... Intermediate concrete member 30 ... Sealing material 31 ... Concrete 32 ... Reinforcement B ... Bearing concrete CB ... Large crane CS ... Small crane F ... Forklift H ... Middle pillar M ... Underground structure R ... Underground structure X1 ... First type Frame X2 ... 2nd mold

Claims (5)

An underground structure including a middle pillar member for connecting beam members arranged in an underground space,
The middle column member includes a middle column main body made of reinforced concrete , and a pair of bearing plates arranged at both ends of the middle column main body ,
Each of the bearing plates is fixed to the beam member, and the middle column body is supported by the bearing plate.
Between the set of bearing plates, a plurality of reinforcing bars are arranged along the longitudinal direction of the central column body,
A binding structure for increasing the lateral binding force of the reinforcing bars is provided at the ends of the reinforcing bars ,
The bundling structure is
An underground structure in which end portions of the plurality of reinforcing bars are converged and formed at a position corresponding to a central portion of a cross section of the middle column main body in the bearing plate . The bundling structure is
High-strength spiral bars provided around the ends of the plurality of reinforcing bars in the bearing plate;
The underground structure according to claim 1, further comprising high-strength concrete in which end portions of the plurality of reinforcing bars are embedded inside the high-strength spiral bars . The outer periphery of the beam member connecting surface that is in contact with the beam member in the bearing plate is a cross-section in the vicinity of the middle column body contact surface or the contact surface that is in contact with the middle column body in the bearing plate. The underground structure of Claim 1 or 2 made larger than the outer periphery. The underground structure according to any one of claims 1 to 3 , wherein a sealing material is interposed between the bearing plate and the middle pillar member. The underground structure according to any one of claims 1 to 4 , wherein at least one of an upper end portion and a lower end portion of the middle pillar main body is reinforced by a steel pipe or a resin pipe.

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