JP5479213B2 - Underfloor inspection structure - Google Patents

Description

  The present invention relates to an underfloor inspection structure. More specifically, the present invention relates to an improvement of an underfloor inspection structure including a reinforced concrete foundation slab or the like.

  Conventionally, in a building where a reinforced concrete cloth foundation is formed in a grid and the floor is supported at the top of the foundation, in order to check the space under the floor, the floor of each grid (each area divided by the cloth foundation) It is necessary to provide an inspection port. When the inspection port is not provided, a person through hole may be provided in the rising portion so that the inspector can go back and forth between the grids (see, for example, Patent Document 1).

  On the other hand, in the foundation in which the rising portion is replaced with a steel beam, the height of a member (such as a bundle) that supports the steel beam can be increased to enable the inspector to move the underfloor space (for example, Patent Documents). 2).

JP 2001-081904 A JP 2001-262586 A

  However, if a person through hole is provided in the rising portion so that the inspector can go back and forth between the grids, there is a problem that large reinforcement is required around the person through hole.

  In addition, if the height of the member that supports the steel beam is increased, the underfloor space can be moved by the inspector, but the floor height of the first floor is increased and the approach is inconvenient, and the overall height of the building There is a problem that becomes larger and it becomes easier to violate the oblique line limitation. On the other hand, if the steel beam is made smaller in order to suppress the height of the floor, there is a problem that the rigidity of the steel beam is lowered.

  It is an object of the present invention to provide an underfloor inspection structure that can move the separated underfloor spaces without applying significant reinforcement and without increasing the first floor height. .

  In order to solve such a problem, the present inventor examined an underfloor inspection structure in a building including a foundation slab, a bundle, a beam, and a floor panel. In order for the inspectors to go back and forth between the grids, a through hole is necessary, but this will affect the basic rigidity or its design. Therefore, the present inventor has made various studies on reconciling these, which are so-called conflicting elements, and has obtained new knowledge that leads to the solution of the problem.

  The present invention is based on such knowledge, and includes a reinforced concrete foundation slab, a bundle installed on the upper surface of the foundation slab, a beam supported by the bundle, and a floor panel supported by the beam. An underfloor inspection structure in a building, which has two beams arranged in a straight line or in a T shape with discontinuous portions having a predetermined interval, and spanned between the two beams at the discontinuous portions. A connecting member and a bundle that supports the end of the beam facing the discontinuous portion, and a space is provided between the foundation slab and the connecting member so that an inspector can move between the base slab and the connecting member. A through portion is formed.

  According to such an underfloor inspection structure, it is possible for the inspectors to move between the underfloor regions separated by the beams without increasing the height of the bundle.

  In such an underfloor inspection structure, it is preferable that a detachable stiffening member is spanned below the connecting member. According to such a structure, a beam having a discontinuous portion is normally connected (by a general purpose other than inspection) with a beam stiffening member, so that it functions like a continuous beam and suppresses bending of the beam. It is also possible to suppress a decrease in yield strength due to discontinuity of the beam when a strength element such as bracing is installed on the beam.

  Further, in one of the two underfloor regions that can move to each other at the pedestrian section, an opening may be provided in the upper floor, and a detachable lid may be provided in the opening. In such a case, the number of openings (inspections) for entering the floor can be reduced, which is advantageous in terms of design and cost. In addition, restrictions on plans and furniture layout due to the presence of inspection ports can be reduced.

  The connecting member preferably includes a plate portion having a flat center. In such a case, it is easy to ensure the height of the area where the inspectors pass, especially the height.

  According to the underfloor inspection structure according to the present invention, it is possible to move the divided underfloor spaces between each other without performing large-scale reinforcement and without increasing the first-floor floor height.

It is a perspective view which shows the first process example (root cutting, PC board installation, anchor bolt installation) at the time of construction of a building. It is a perspective view which shows the bar arrangement process of a basic slab. It is a perspective view which shows the process of installing a bundle in an anchor bolt. It is a perspective view which shows the process of installing a steel frame beam. It is a perspective view which shows the process of installing a horizontal brace. It is a perspective view which shows the process of installing a plate-shaped heat insulating material etc. in the outer peripheral part of a foundation slab. It is a perspective view which shows the process of placing concrete. It is a perspective view which shows the process of installing a beam upper part frame. It is sectional drawing which shows an example of the foundation of the constructed building. It is sectional drawing which shows an example of the foundation of the state in which the horizontal brace was installed. It is a top view which shows the structural example of the steel beam of the part in which the horizontal brace was installed through the hit. It is a perspective view which shows the form example of an outer periphery bundle | flux. It is a perspective view which shows the other example of an outer periphery bundle | flux. It is a top view which shows the example of the form of the underfloor inspection structure concerning this invention. It is sectional drawing which shows the example of a form of the underfloor inspection structure containing a traffic part.

  Hereinafter, the configuration of the present invention will be described in detail based on an example of an embodiment shown in the drawings.

  FIG. 15 shows an embodiment of the present invention. The building A exemplified in the present embodiment is a two-story steel frame industrialized house by a beam winning method having a flat module of 305 mm. However, this is only a preferable application example, and the scope of application of the present invention is not limited thereto.

  In the building A, the foundation slab 10, a bundle 20 (see FIG. 3 and the like) placed and fixed on the upper surface of the foundation slab 10, a beam (hereinafter also referred to as a first-floor floor beam) 30 supported by the bundle 20 ( (See FIG. 4 etc.) A pillar (hereinafter also referred to as a first floor pillar) 40 (see FIG. 8) placed and fixed on the first floor beam 30 is arranged to connect the upper ends of the first floor pillars 40. 2nd floor beams (not shown) 2nd floor pillars (not shown) placed on the 2nd floor beams, R floor large beams (not shown), members such as load bearing elements installed between two adjacent pillars The basic frame is arranged corresponding to a plurality of selected reference lines (X-direction reference line, Y-direction reference line) respectively (set to be an integer multiple of the module). It is configured. Furthermore, in the building A, each floor is composed of floor panels made of ALC (Autoclaved Light-weight Concrete) supported by each floor beam, and each floor is constructed using the outer peripheral beam. An outer wall panel or an opening panel made of ALC or the like is attached to form an outer wall.

  In the present embodiment, the foundation slab 10 is entirely solid. In the foundation slab 10, a range of a predetermined width along the street (a range in which the load from the bundle 20 is dispersed, for example, a diagonal line drawn at an angle of 45 degrees from the edge of the lower flange of the bundle 20 (see FIG. 9 (refer to the broken line in FIG. 9) and the range of the intersection of the bottom surface of the foundation slab 10), the bar arrangement amount is calculated as a foundation beam that opposes the ground reaction force (see FIGS. 9 and 10). For other areas, the amount of bar arrangement is determined by regarding the slab as a fixed four side that receives ground reaction force. In this embodiment, the solid foundation type foundation slab 10 is illustrated, but is not limited to such a solid foundation type, for example, has a desired width according to the ground strength along the street. A footing type can also be used. The level of the upper end of the foundation slab 10 of the present embodiment is set higher than the ground surface (see FIGS. 9 and 10).

  The bundle 20 is placed on the upper surface of the foundation slab 10, protrudes from the upper end surface of the foundation slab 10, and supports the above-mentioned first floor beam 30 (see FIG. 4 and the like). In the present embodiment, anchor bolts (anchor frames) 11 are embedded in the foundation slab 10 in advance (see FIG. 1 and the like), and the bundle 20 is joined to the upper end portion of the anchor bolts 11 with, for example, nuts and fixed (see FIG. 1). (See 3 etc.). The bundle 20 has a role of efficiently transmitting the load transmitted from the pillar (first floor pillar 40) to the foundation slab 10, and is directly below the first floor pillar 40 standing on at least the floor beam 30 (on the street). Is installed using a bolt hole in the lower flange of the middle part of the joint box 21 or the first floor beam 30 and supports the first floor beam 30.

  The bundle 20 has a lower flange 20b joined to the upper end portion of the anchor bolt 11, an upper flange 20a joined to, for example, the joint box 21, and a cross section (horizontal section) connecting these flanges 20a and 20b, for example, a cross. (Including a cross-shaped web) 20c. The upper flange 20a is provided with an upper bolt hole 20d for joining the joint box 21, and the lower flange 20b is provided with a lower bolt hole 20e for joining the bundle 20 to the upper end of the anchor bolt 11. (See FIGS. 12 and 13).

  Such a bundle 20 is appropriately arranged on the outer peripheral portion (that is, the portion near the outer wall) and the inner peripheral portion (that is, the portion near the inside of the building A) of the building A. Among these, a bundle (also referred to as an outer circumferential bundle in this specification) 20 arranged along the edge of the foundation slab 10 in the outer peripheral portion (outer street) is outside the building (a portion near the outer periphery of the building A). The edge positions of the upper flange 20a and the lower flange 20b coincide, and on the inner side of the building (the side facing the interior of the building A), the lower flange 20b extends toward the inner side of the building than the upper flange 20a. The web 20c has a shape (offset shape) formed in a divergent shape from the end edge of the upper flange 20a to the end edge of the lower flange 20b (see FIG. 9, FIG. 12, etc.). In addition, at the entrance corner and the exit corner of the building A, the lower flange 20b extends from the upper flange 20a in two directions along the outer wall, and the extended web 20c extends from the edge of the upper flange 20a to the lower flange. The outer peripheral bundle 20 formed so as to spread toward the end edge of 20b is employed (see FIGS. 3 and 13).

  By using such an offset-shaped outer peripheral bundle 20, the load is distributed and transmitted to a wider range of the foundation slab 10, and the range that can be regarded as the first-floor beam 30 corresponds to the offset direction of the outer peripheral bundle 20. It can be offset inward. That is, in the present embodiment, the amount of reinforcing bars is set by regarding the range of the width according to the contact dimension of the lower flange 20b of the outer peripheral bundle 20 of the foundation slab 10 as the beam 30 that opposes the ground reaction force, More specifically, the arrangement of the intersection between the oblique line drawn at an angle of 45 degrees from the edge of the lower flange 20b of the outer peripheral bundle 20 and the bottom surface of the foundation slab 10 is regarded as a foundation beam that opposes the ground reaction force. The amount is calculated. Therefore, when the offset outer peripheral bundle 20 in which the lower flange 20b extends more than the upper flange 20a is used, the intersection with the bottom surface of the foundation slab 10 by the length L (see FIG. 9) that the lower flange 20b extends. (See FIG. 10 etc.). According to this, by flowing the building load transmitted from the first floor column 40 in the building inner direction, it is possible to distribute and transmit the building load while keeping the extension dimension of the foundation slab in the building outer direction small. The width that can be regarded as a beam against the ground reaction force can be narrowly estimated, and the overcrowded arrangement of reinforcing bars can be prevented. Thus, since it becomes possible to suppress the extension dimension of the foundation slab 10 in a building outer peripheral part small, without being disadvantageous on a structural plan, for example, it is a case where sufficient separation dimension is not ensured between adjacent land boundaries. However, the construction can be performed without hindering the arrangement of the drain pipe and the like. Furthermore, such a structure is also suitable when performing a water stop treatment for rust prevention of the internal steel member. To give a specific example, by raising the cover material (as an example, a plate-like heat insulating material) in advance instead of the formwork (dam plate) before placing concrete, and improving the adhesion with the foundation slab 10, Even if it does not perform special water stop treatment, it is possible to obtain a state in which a certain level of water stop effect can be expected if not complete. Furthermore, it is possible to prevent the appearance of the building A from becoming unfavorable by preventing the RC portion and the water stop treatment portion from being exposed from the ground surface. For example, by arranging a cover material (for example, a plate-like heat insulating material) so as to cover the lower end of the basic slab 10, it is possible to obtain a design-preferable configuration that is a single material and has no steps. It becomes.

  Moreover, the anchor bolt 11 installed in the foundation slab 10 to fix the lower flange 20b of the outer peripheral bundle 20 to the outer peripheral bundle 20 as described above is connected to the outer periphery of the building A (the first floor floor beam 30, the first floor). The center position of the pillar 40, specifically, the outer shape (the outer shape of the horizontal cross section) may be offset closer to the inside of the building A than the center of the substantially square pillar (centroid). In such a case, the position of the anchor bolt 11 is closer to the inside of the building A, and the marginal dimension from the anchor bolt 11 (dimension from the anchor bolt 11 to the end edge of the foundation slab 10) is sufficiently ensured. It is preferable in terms of strength.

  The beam 30 is made of, for example, an H-shaped steel (including a shaped steel called an I-shaped steel), and gusset plates 34 having ends bent into L-shapes and formed with bolt holes at both ends are joined by, for example, welding. (See FIG. 4 etc.). The beam 30 includes not only a large beam (first-floor floor beam) arranged on the street, but also a small beam spanned between opposed large beams to support the floor panel. Note that the small beam may be bridged between the large beam and another small beam.

  Further, the upper flange 30a and the lower flange 30b of the beam 30 have bolt holes 30d through which bolts for joining the module pillars are inserted at equal intervals based on the module (see FIG. 4 and the like). The bolt hole 30d is drilled so as to be located on the intersection of the plane-view reference line. In addition, bolt holes 30d through which bolts for joining other beams 30 are also inserted into the web 30c at regular intervals with a pitch based on the module. Furthermore, large diameter holes (for example, a diameter of 125 mm) 30e are formed in the web 30c of the beam 30 at predetermined intervals (see FIG. 4 and the like).

  When joining the ends of the beams (first floor beams) 30, the joint box 21 is used in this embodiment (see FIG. 4 and the like). The joint box 21 is configured by welding a square upper flange 21a and a lower flange 21b to upper and lower ends of a cross-shaped web 21c in plan view. When joining the beam 30 to the joint box 21, the two surfaces of the gusset plate 34 of the beam 30 are brought into contact with the two surfaces of the web 21c perpendicular to each other, the bolt holes in the bent portion of the gusset plate 34 and the corresponding joint box Bolts are inserted into 21 bolt holes and bolted together. It is possible to join the beam 30 from four directions to one joint box.

  Further, when joining the small beam (indicated by reference numeral 30 'in FIG. 4) to the intermediate portion of the other beam 30, the bent portion of the gusset plate 34 is brought into contact with the surface of the web 30c of the intermediate portion, Join the bolts. In addition, the said structure is common in the structure of the beam 30 in an upper floor.

  The column 40 is arranged at the intersection of the street and the reference line orthogonal to the street, and the upper and lower ends are joined using the bolt holes 30d of the upper and lower flanges 30a and 30b in the middle portion of the joint box 21 or the beam 30 (see FIG. 8).

  The load-bearing elements 41 are bolted to the inner surfaces of the two pillars 40 arranged at a predetermined interval (for example, 610 mm, 915 mm, etc.). The load-bearing element 41 is composed of, for example, a brace (cross frame) or the like (see FIG. 8).

  A horizontal brace (stiffener) 31 is installed on the floor structure of the first floor to suppress deformation of the beam 30 and the like during concrete placing work (see FIG. 5 and the like). The horizontal brace 31 installed on the floor construction surface is a member for securing the in-plane rigidity of the first floor after the building is completed. If such a horizontal brace 31 is attached in the vicinity of the upper end of the beam 30 directly or via a fire hitting 35, the deformation suppressing effect of the beam 30 and the like, and the workability and underfloor utilization at the time of foundation formation are further improved. (See FIGS. 10 and 11). In addition to the horizontal brace 31 exemplified here, it is also possible to use a fire beam (fired base, fired metal) or the like as a stiffener.

  Further, the first floor (indicated by reference numeral 70 in FIG. 15) has a dimension corresponding to the size of the floor panel (indicated by reference numeral 36 in FIG. 15) and has an opening (reference numeral in FIG. 14). 53), an underfloor inspection port 51 for underfloor inspection is provided (see FIG. 14). However, the underfloor space is divided into fine sections by the beams 30, and the height of the bundle 20 is, for example, about 100 mm. When the bundle 20 is made high, it becomes easy to violate legal restrictions such as height restriction and oblique line restriction. The inspectors cannot go under the beam 30. Therefore, it is necessary to provide an underfloor inspection port for each section. However, it is not desirable from the viewpoint of design that the underfloor inspection port itself or the metal edge of the lid can be seen in many places, and cannot be installed on the floor plan (or underfloor inspection port) Priority may be placed on the installation of the floor space to reduce the degree of freedom of the floor plan).

  In order to cope with such a case, in this embodiment, instead of supporting both ends of some of the beams 30, the beams 30 are divided at intermediate portions to provide discontinuous portions with a predetermined width. Thus, a communication part 60 is formed (see FIG. 15). The width of the discontinuous portion is at least a width through which an inspector can pass. In addition, the ends of the divided beams 30 (strictly speaking, the joint box 21 coupled to the ends of the beams 30) are supported by the bundle 20, and the connecting member 37 is hung on the discontinuous portions (personnel portions 60). The floor panel 36 can be passed and supported so that the inspectors can pass through the space between the connecting member 37 and the foundation slab 10 (person passage section 60) (see FIG. 15). ).

  The connecting member 37 is a smaller member than the beam 30. In the present embodiment, the connecting member 37 is formed in a substantially arch shape with a flat plate portion 37a at the center and bracket portions 37b that cantilever-support both ends of the plate portion 37a (see FIG. 15). When the short side of the rectangular floor panel 36 is supported by the connecting member 37 (when the connecting member 37 is spanned in the short side direction of the floor panel 36 and a part of the floor panel 36 is supported by the connecting member 37). The central portion of the connecting member 37 is preferably disposed near the center of the floor panel 36. The reason for this will be briefly described below with examples.

  That is, the floor panel 36 made of ALC has a width of, for example, 610 mm (= twice that of a flat module), and is generally reinforced by reinforcing bars on the premise of support on two short sides. Further, the floor panel 36 is designed to be safely supported if it is supported at both ends of the short side by approximately a quarter of the length of the short side (for example, 152.5 mm). That is, it is designed so that safety is ensured even if the range of about 305 mm at the center of the short side is not supported. The width of the plate portion is about one half of the width of the floor panel 36 (short side length). The plate portion does not have strength and rigidity that can withstand the support of the floor panel 36, but the bracket portion has strength and rigidity that can withstand the support of the floor panel 36. Therefore, if the central portion of the connecting member 37 is disposed near the center of the floor panel 36, the floor panel 36 can be supported without any structural problem. In addition, when it is located on the long side of the floor panel 36 and does not support the short side, the connecting member 37 is unnecessary in the sense of supporting the floor panel 36, but the position accuracy of the divided beams is maintained (preventing collapse). It works effectively in the sense of

  Further, in addition to the connecting member 37 described above, a stiffening member 38 of the beam 30 that is detachable can be bridged over the discontinuous portion of the beam 30 by bolting or the like. Normally (generally, when inspection work is not performed), the beam 30 in which the connecting member 37 and the stiffening member 38 are separated in cooperation with each other is made to function like a continuous beam. The amount of deflection of the beam 30 can be reduced, and when the load bearing element 41 such as bracing described later is installed on the beam 30, A decrease in yield strength can also be suppressed. When inspection is necessary, the stiffening member 38 of the beam 30 can be removed for inspection. For example, in the present embodiment, a detachable stiffening member 38 is stretched below the connecting member 37 (see FIG. 15). Although not shown in detail, it is preferable that the stiffening member 38 and the beam 30 (or the joint box 21) be connected to each other as the rigidity is increased.

  Moreover, in this embodiment, the opening of the underfloor inspection port 51 is provided in the upper first floor 70 in one of the two underfloor regions that can be moved to each other by the pedestrian 60. In such a case, the number of openings (underfloor inspection port 51) for entering under the floor can be reduced, which is advantageous in terms of the design and cost in the room of the building A. In addition, the plan and furniture layout restrictions due to the presence of the underfloor inspection port 51 can be reduced. A removable cover 52 is provided at the opening of the underfloor inspection port 51 (see FIGS. 14 and 15). In addition, the 1st floor 70 provided with an opening is formed by laminating, for example, a moisture-proof sheet, a gypsum board, a plywood, a floor finishing material, and the like (see FIG. 15).

  A cover material is attached to the outer periphery of the building A along the edge of the foundation slab 10 and the beam 30 on the outer periphery. In the case of the present embodiment, the cover material is made of a plate-like heat insulating material (foamed polystyrene foam or the like) 14 made of a synthetic resin foam, a resin mortar or the like applied to the surface of the plate-like heat insulating material 14. In the present embodiment, the upper end of the plate-like heat insulating material 14 is held by a holder (not shown) locked to the beam 30, and has a reaction force on the beam 30 against the side pressure caused by the concrete when placing the concrete. (See FIGS. 9 and 10). The plate-like heat insulating material (cover material) 14 can also serve as a formwork (dam plate) on the outer periphery of the basic slab 10. The holding tool may be a temporary member at the time of placing concrete or a permanent member. Reference numeral 32 denotes a metal receiver for the outer wall panel (see FIG. 9). The receiver 32 of this embodiment has an inverted T-shaped cross section, and the tip is bent obliquely downward so that the sealing material can be filled.

  The plate-like heat insulating material 14 also serves as a concrete formwork (dam plate) of the foundation slab 10, and is installed in advance before placing concrete (see FIG. 6). Therefore, the level of the lower end of this plate-shaped heat insulating material 14 is the same as the level of the lower end of the foundation slab 10 (see FIG. 9 etc.). By installing the plate-like heat insulating material 14 in advance, the degree of adhesion with concrete is increased, and the upper end level of the foundation slab 10 is set higher than the ground surface, so that it is possible to suppress the intrusion of water into the building A. it can. Moreover, since the edge part of the foundation slab 10 is not exposed, it is preferable in design. Furthermore, when penetrating equipment piping or the like, there is an advantage that it can be easily processed.

  In addition, the space | interval holder 15 which prevents the fall of the upper end part of the plate-shaped heat insulating material 14 to the building interior side is interposed between the plate-shaped heat insulating material 14 and the beam 30. As the distance holder 15, a member made of the same material as the plate-like heat insulating material 14 can be used.

  Then, it demonstrates below, giving an example about the construction procedure of the foundation of the building A. FIG.

  First, the ground is root-cut (root-cut), and crushed stone 17 is spread and rolled (see FIG. 1). A PC (precast concrete) plate 16 is installed at a bundle position (position where the bundle 20 is installed) on the bottom of the root cutting (see FIG. 1). When the anchor bolt 11 is fixed to the PC plate 16, the anchor bolt 11 is fixed to the fixing plate 18 (see FIG. 1).

  Subsequently, the reinforcing bars 12 are arranged (see FIG. 2). In the present embodiment, the reinforcing bars 12 are densely arranged in a portion (a range of a predetermined width along the street) regarded as a foundation beam according to the calculated arrangement amount.

  Thereafter, the bundle 20 is installed on the anchor bolt 11 (see FIG. 3). First, a lower nut for temporarily supporting the bundle 20 is screwed into the anchor bolt 11, and the level (height) of the bundle 20 is adjusted. Subsequently, the anchor bolt 11 is inserted into the bolt hole of the lower flange 20b of the bundle 20, and the upper nut is further screwed to fix the bundle 20 (see FIG. 9 and the like). In FIG. 9 and FIG. 10, the anchor bolt 11 and the lower flange 20b are joined differently. That is, in FIG. 9, since the position of the anchor bolt 11 with respect to the outer peripheral bundle 20 is offset from the case of FIG. 10, the anchor bolt 11 is a web 20c of the outer peripheral bundle 20 (a web orthogonal to the end-spread web 20c). 10), the anchor bolt 11 is inserted into the lower bolt hole 20e of the lower flange 20b and fastened with a nut from above the lower flange 20b as shown in FIG. Therefore, in such a case, a tap hole that does not penetrate through the lower flange 20b is provided, and the anchor bolt 11 is screwed and fixed thereto (see FIG. 9).

  Subsequently, the beam 30 is placed on the bundle 20 and fixed using bolts and nuts (see FIG. 4).

  Next, the plate-shaped heat insulating material 14 is erected on the outer periphery of the foundation. Further, a spacing holder 15 is provided along the outer surface of the plate-like heat insulating material 14 (see FIG. 6).

  Moreover, the connection member 37 is attached to the part (the discontinuous part formed by dividing the intermediate part of the beam 30) in which the traffic part 60 is formed (refer FIG. 14, FIG. 15). Further, a detachable stiffening member 38 is attached below the connecting member 37 (see FIG. 15).

  Further, a stiffener such as a horizontal brace 31 is attached to the first floor construction surface, and the diagonal position of the beam 30 is confirmed to adjust the beam position (distortion correction) (see FIG. 5). As described above, it is preferable to install the horizontal brace (stiffener) 31 at a high position on the construction surface. However, if the level of the upper flange 30a of the beam 30 is exceeded, it becomes an obstacle to laying the floor panel. It is. For example, a procedure of adjusting the beam position with a temporary horizontal brace and then fixing with a fire beam or the like may be adopted.

  Thereafter, concrete is placed (see FIG. 7). In the present embodiment, concrete is placed in accordance with the lower end level of the bundle 20 (see FIG. 9 and the like). After concrete curing, a beam upper frame (first floor column 40 etc.) can be installed (see FIG. 8).

  Prior to the concrete placing step, the work floor (road plate) 33 may be hooked using the beams 30 (see FIG. 7). By using the beam 30 to hang the work floor 33, it is not necessary for the operator to step into the concrete at the time of placing and finishing, and the work of removing the footprints at the time of finishing without making the site dirty. When the work floor 33 is stretched over the lower flange 30b of the beam 30, movement in the longitudinal direction is restricted by the web 30c, and the work floor 33 can be more reliably latched so as not to slip off.

  According to the construction method of the building A according to the present embodiment, the bundle 20 can be supported by the anchor bolt (anchor frame) 11 and the foundation can be formed by the bundle 20 in a pre-positioned state. With a structure that is not easily affected by bending or the like, the foundation can be constructed with high accuracy. According to such a construction method, the necessary work is reduced while maintaining the advantages of the steel foundation (easiness of adjusting the top end accuracy, high degree of freedom in the installation position of the pillars 40, etc., and shallow depth of installation). Construction accuracy can be improved while shortening the construction period.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the above-described embodiment, an example in which an intermediate portion of the beam 30 is divided to form a discontinuous portion (passing portion 60) (see FIG. 15) is shown, but this is only a preferable example. In addition, for example, a discontinuous portion (personnel portion 60) can be formed even in a portion where the beam 30 is joined to the other beam 30 in a T shape. In any case, the end of the beam 30 facing the discontinuous portion is supported by the bundle 20 (see FIG. 15 and the like).

  In the above-described embodiment, the building A having the structure in which the beam 30 is directly supported by the bundle 20 has been described as an example (see FIG. 8 and the like). The present invention can also be applied to a building A having a structure in which 30 is indirectly supported through another beam supported by the bundle 20.

  The present invention is suitable for application to all steel structure buildings.

DESCRIPTION OF SYMBOLS 10 ... Foundation slab, 11 ... Anchor bolt, 20 ... Bundle, 30 ... First floor beam (beam), 36 ... Floor panel, 37 ... Connection member, 37a ... Plate part, 38 ... Stiffening member, 51 ... Underfloor inspection port , 52 ... Lid, 60 ... Passenger part, 70 ... First floor (floor), A ... Building

Claims (4)

An underfloor inspection structure in a building comprising a reinforced concrete foundation slab, a bundle installed on an upper surface of the foundation slab, a beam supported by the bundle, and a floor panel supported by the beam,
Two beams arranged in a straight line or in a T-shape with discontinuous portions having a predetermined interval;
A connecting member spanned between the two beams in the discontinuous portion;
A bundle that supports the end of the beam facing the discontinuity,
An underfloor inspection structure characterized in that a space is provided between the foundation slab and the connecting member so that an inspector can move and a person passage portion is formed.   The underfloor inspection structure according to claim 1, wherein a detachable stiffening member is hung under the connecting member.   2. One of the two underfloor regions that can move to each other at the person-passing portion is provided with an opening in the upper floor, and a detachable lid is provided in the opening. Or the underfloor inspection structure described in 2.   The underfloor inspection structure according to any one of claims 1 to 3, wherein the connecting member includes a plate portion having a flat center.

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