Column end joint structure
09828773 · 2017-11-28
Assignee
Inventors
Cpc classification
E04C3/36
FIXED CONSTRUCTIONS
E04B2001/2692
FIXED CONSTRUCTIONS
E04H9/021
FIXED CONSTRUCTIONS
International classification
E04C3/36
FIXED CONSTRUCTIONS
Abstract
In a column end joint structure for joining an end of a column made of flat wooden material having a rectangular cross-section to a joining member, splitting generation at the end of the column is controlled. An expansion of crack is controlled when splitting generated. A cutout portion is provided in each of ends in a longitudinal direction of a column end face, and a joint fitting is coupled inside the cutout portion by a joint bolt. The joint fitting is coupled to a foundation by an anchor bolt. Joint fittings are arranged in the longitudinal direction of the end face inside each cutout portion. One joint fitting is located contacting or close to a surface of the column inside the cutout portion such that the joint fitting side face and the surface of the column inside the cutout portion restrain a displacement orthogonal to the column axis.
Claims
1. A column end joint structure comprising: a column made of a flat wooden material having a substantially rectangular cross-section, a length of one side of the column being larger than a length of an adjacent another side of the column; a joining member to which an end portion of the column is joined; a plurality of joint fittings for joining the column to the joining member; and a plurality of joint bolts for coupling the joint fittings to the column; wherein a cutout portion is provided in each of both ends in a longitudinal direction of an end face of the column; the joint fittings are coupled to the column by the joint bolts inserted in an axial direction of the column inside the cutout portion; the joint fittings are coupled to the joining member; two of the joint fittings are arranged apart from each other in the longitudinal direction of the end face of the column inside each of the cutout portions; one of the two joint fittings is located at a position in contact with or close to a surface in the axial direction of the column inside at least one of the cutout portions such that a side face of the joint fitting and the surface in the axial direction of the column inside the at least one of the cutout portions restrain a relative displacement in a direction orthogonal to the axis of the column, at the end portion of the column, screws are threaded from a short side face of a column cross-section into the longitudinal direction of the cross-section; a tip of each of the screws passes through a space between the joint bolts and a wider side face of the column and aside by the joint bolts inserted in the axial direction of the column and reaches a position exceeding positions of the joint bolts, and the tip of each of the screws being pointed so that each of the screws can be self-threaded into the wooden material.
2. A column end joint structure comprising: a column made of a flat wooden material having a substantially rectangular cross-section, a length of one side of the column being larger than a length of an adjacent another side of the column; a joining member to which an end portion of the column is joined; a plurality of joint fittings for joining the column to the joining member; a plurality of joint bolts for coupling the joint fittings to the column; and a plurality of screw members, wherein a cutout portion is provided in each of both ends in a longitudinal direction of an end face of the column; the joint fittings are coupled to the column by the joint bolts inserted in an axial direction of the column inside the cutout portion; the joint fittings are coupled to the joining member; two of the joint fittings are arranged apart from each other in the longitudinal direction of the end face of the column inside each of the cutout portions; one of the two joint fittings is located at a position in contact with or close to a surface in the axial direction of the column inside at least one of the cutout portion such that a side face of the joint fitting and the surface in the axial direction of the column inside the at least one of the cutout portion restrain a relative displacement in a direction orthogonal to the axis of the column, each of the screw members has a spiral blade body on an outer peripheral surface of a rod-shape shaft portion and a hole in the axial direction from an end face of the shaft portion; two of the screw members are threaded into the axial direction of the column from inside each of the cutout portions; each joint bolt is inserted into the respective hole in each of the respective screw members; each joint bolt is threaded into an internal thread formed in a bottom portion of each respective hole; at the end portion of the column, screws are threaded from a short side face of a column cross-section into the longitudinal direction of the cross-section; a tip of each of the screws passes through a space between the screw member and a wider side face of the column and aside by the joint bolts inserted in the axial direction of the column and reaches a position exceeding positions of the joint bolts; and the tip of each of the screws is pointed so that each of the screws can be self-threaded into the wooden material.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(17) Description is hereinafter made of embodiments of the present invention with reference to the drawings.
(18)
(19) This structural framework includes a Rahmen frame 10 in which a wooden column 1, a wooden beam 2, and a foundation 3 are joined such that a bending moment is transmittable between the wooden column 1 and the wooden beam 2, as well as between the wooden column 1 and the foundation 3. This structural framework is formed by combining a plurality of Rahmen frames 10 on the concrete foundation 3. Each Rahmen frame 10 has a so-called beam-priority frame structure in which the wooden beam 2 is placed on the wooden column 1 to be joined thereto. A cross-sectional shape of the column 1 which configures each Rahmen frame 10 is flat and rectangular, long on a side in an axial direction of the beam 2 supported thereby and short on a side in a direction orthogonal to an axis of the beam 2. In addition, a cross-sectional shape of the beam 2 is also flat and rectangular, long in a vertical direction and short in a horizontal direction. Accordingly, a joint portion between the column 1 and the beam 2 in each Rahmen frame has such a structure where the joint portion mainly resists bending in only one direction which generates a compression region and a tensile region in a longitudinal direction of the cross-section. In addition, as to a Rahmen frame 10a and another Rahmen frame 10b, an end face of a beam 2a of the one Rahmen frame 10a abuts a side face of a beam 2b of the other Rahmen frame 10b to be joined therewith, and thus a three-dimensional Rahmen structure is obtained.
(20)
(21) This joint structure is for joining a lower end of the column 1 to the foundation 3, as a joining member of the column 1, via a joint fitting 30.
(22) A cutout portion 1a is provided on each of both ends in the longitudinal direction of a lower end face of the column 1, and two screw members 11 are threaded into the column 1 in the axial direction thereof from each cutout portion 1a. These cutout portions 1a are formed by cutting out portions that are substantially shaped as rectangular parallelepipeds from both ends in the longitudinal direction of the end face of the column 1 into the axial direction of the column 1. In other words, both corners at ends on a wider side face of the column 1 are cut out rectangularly. The two screw members 11 are threaded into the column 1 from a surface substantially orthogonal to the axis of the column inside the cutout portions into the axial direction, the two screw members 11 being arranged in the longitudinal direction of the cross-section of the column 1. Further, the two joint fittings 30 are arranged in the longitudinal direction of the cross-section of the column in each cutout portion 1a, and each of these joint fittings is coupled to the respective screw members 11 with joint bolts 13.
(23) As shown in
(24) On the one hand, anchor bolts 12 in the vertical direction are embedded in the foundation 3 at positions corresponding to the positions into which the respective screw members 11 of the column 1 are threaded. Head portions of the anchor bolts 12 are protruding from an upper surface of the foundation 3. The upper surface of the foundation 3 is finished to be flat by a surface preparation material 3a, and the joint fittings 30 are supported thereon via steel base plates 4. Further, the joint fittings 30 are fixed to the foundation 3 by fastening nuts 18 threadedly engaged with the anchor bolts 12. Accordingly, the foundation 3 and the column 1 are joined via the four sets of anchor bolts 12, the joint fittings 30, the joint bolts 13, and the screw members 11. Here, reference numeral 5 denotes an elastic member interposed between the column 1 and the foundation 3, and reference numeral 6 denotes a base fixed to the foundation 3.
(25) Between the column 1 and the foundation 3, out of the four joint fittings 30 arranged in the longitudinal direction of the cross-section of the column 1, the two joint fittings 30a arranged on a side closer to the center of the column 1 are arranged such that each joint fitting 30a is in proximity to a surface 1b in the axial direction inside the cutout portion 1a of the column 1. A gap between the joint fitting 30a and the surface 1b is approximately 1.5 mm. In other words, by providing the cutout portions 1a on both ends in the longitudinal direction of the cross-section of the column 1, the center portion of the column 1 protrudes at the end thereof. Side faces of this protruding portion 1c face the side faces of the joint fittings 30 in proximity thereto. The gap between the column 1 and the joint fitting 30 can be arbitrarily set in accordance with the purpose, scale, or the like of the structure. The column 1 and the joint fitting 30 may even be in contact with each other.
(26) As shown in
(27) The internal thread 11c is provided at the substantially center portion of a total length in the axial direction of the screw member 11. The tip of the joint bolt 13 is threadedly engaged with the substantially center portion in the axial direction of the screw member 11. Accordingly, force transmitted from the raised portion 11a provided on the screw member 11 to the column 1 is distributed to a wide range in the axial direction of the screw member 11. Thus, concentration of a large stress on the column 1 can be avoided. Here, reference numeral 11d denotes a small hole that penetrates through the screw member from the bottom of the hollow hole 11b to an opposite end face of the screw member 11. This small hole provides ease of processing such as anti-corrosion treatment of the screw member 11.
(28) As shown in
(29) A bolt hole 34 is provided in an upper-side horizontal plate portion 31. The joint bolt 13 is inserted into the bolt hole 34, and the fastening nut 17 is threadedly engaged with the joint bolt 13 to join the joint bolt 13 and the joint fitting 30.
(30) On the one hand, a lower-side horizontal plate portion 32 faces the upper face of the foundation 3 via the base plate 4. The lower-side horizontal plate portion 32 is fixed to the foundation 3 by the anchor bolt 12 a lower end of which is embedded in the foundation and by the fastening nut 18 threadedly engaged with the anchor bolt.
(31) A circular hole is formed in the lower-side horizontal plate portion 32, and a circular plate 36 is fitted into this circular hole from inside the joint fitting 30 having a box-like shape. Further, the circular plate 36 is rotatable in the circumferential direction in a state where the circular plate 36 is fitted in the circular hole. This circular plate 36 is provided with a slot like oblong hole 37 into which the anchor bolt 12 can be inserted. The oblong hole 37 has an axis in the radial direction from the center of the circular plate 36. Thus, by adjusting a position in the oblong hole 37 through which the anchor bolt 12 is inserted and by rotating the circular plate to adjust the direction of the axis of the oblong hole 37, relative positions of the anchor bolt 12 and the joint fitting 30 can be adjusted. Thus, the column 1 can be easily erected at a predetermined position.
(32) Here, preferably, the joint fitting 30 is set such that a large deformation does not occur when tensile force or compression force is exerted from the column 1 or such that breakage thereof does not occur before facture of the joint bolt 13. Setting of a member thickness and selection of a material is preferably carried out such that the joint fitting 30 has sufficient strength and rigidity.
(33) As shown in
(34) The tip-end external thread portion 15a is threadedly engaged with the internal thread 11c formed inside the hollow hole 11b of the screw member 11 to join the front shaft portion 15 with the screw member 11. Further, from the tip-end external thread 15a to the flange portion 14, an outside diameter of the front shaft portion 15 is formed smaller than an inside diameter of the hollow hole 11b. Thus, an outer peripheral surface of the front shaft portion 15 is separated from an inner peripheral surface of the hollow hole 11b of the screw member 11. As a result, expansion and contraction of a portion rearward of the tip-end external thread portion 15a of the front shaft portion 15 is permitted inside the hollow hole 11b.
(35) The flange portion 14 is formed to stretch out laterally from the outer peripheral surface of the front shaft portion 15 or the rear shaft portion 16. By inserting the front shaft portion 15 into the hollow hole 11b of the screw member, threading the tip-end external thread portion 15a into the internal thread 11c provided at the bottom of the hollow hole 11b, and tightly fastening thereto, the flange portion 14 is pressed against an end face of the screw member 11. In other words, the tensile force is introduced to a portion between the tip-end external thread portion 15a and the flange portion 14 of the joint bolt 13, resulting in generation of elastic elongation deformation.
(36) The rear shaft portion 16 is provided with the rear-end external thread portion 16a formed on the rear-end side and an expanded diameter portion 16b having a larger diameter than a diameter of the rear-end external thread portion 16a.
(37) The rear shaft portion 16 is inserted into the bolt hole 34 provided in the joint fitting 30, and the fastening nut 17 is threadedly engaged with the rear-end external thread portion 16a. Further, by sandwiching the upper-side horizontal plate portion 31 of the joint fitting 30 between the flange portion 14 and the fastening nut 17 and then fastening the fastening nut 17, the joint bolt 13 can be coupled with the joint fitting 30. Note that, reference numeral 14a denotes a recess for locking a tool from behind the joint bolt 13 and imparting rotational force thereto. Further, reference numeral 16b denotes an expanded diameter portion of the rear shaft portion.
(38) The joint bolt 13 is preferably made of a material such as mild steel having a large plastic deformation until fracturing. Material for the joint bolt 13 may be selected and the diameter may be set in accordance with portions to be provided with the joint structure in a structure and with dimensions or the like of the members that constitute the structure.
(39) In such a column end joint structure, when horizontal force acts in the longitudinal direction of the cross-section of the column 1 and the bending moment is generated at the lower end of the column 1, compression force acts from the column 1 on the foundation 3 via the screw member 11 and the joint fitting 30 in the vicinity of one end edge in the longitudinal direction, while the tensile force acts from the screw member 11 on the joint bolt 13, the joint fitting 30, and the anchor bolt 12 in the vicinity of the other end edge in the longitudinal direction. Further, when a degree of tensile stress of the joint bolt 13 exceeds a degree of yield stress, plastic deformation is generated at the front shaft portion 15 of the joint bolt 13. When the tensile force and the compression force repeatedly act on the joint bolt 13 due to earthquake motion and plastic elongation and contraction are generated thereby, energy of the earthquake motion is absorbed by stress-strain hysteresis thereof, and thus vibration of the structure is damped.
(40) On the one hand, shearing force in the horizontal direction, in addition to the bending moment, acts on the lower end of the column 1, and the shearing force is transmitted from the screw member 11 to the foundation 3 via the joint bolt 13 and the joint fitting 30. At this time, force in the horizontal direction acts on the column 1 from a side face of the screw member 11, and force that causes a crack to form in a direction along the screw member is generated in the vicinity of the end of the column. Because the long screws 19 act against such force to control cracking and the four sets of the screw members 11, the joint bolts 13, and the joint fittings 30 are arranged, the horizontal force is transmitted in a distributed manner Thus, splitting is less likely to be generated.
(41) In addition, the splitting is likely to be generated at the position of the screw member 11 threaded into the vicinity of the both ends in the longitudinal direction of the end face of the column 1. When the splitting is generated, the screw member 11 is displaced with respect to the column 1, and a function of bearing the horizontal force is deteriorated. However, even if the splitting is generated in the vicinity of the ends in the longitudinal direction, the horizontal force is transmitted to the joint fitting 30 and the foundation 3 by the screw member 11 arranged on the center side of the column, and thus the displacement of the column 1 is limited to a small value. In addition, when the splitting is generated and the column 1 is displaced, the surface 1b in the axial direction inside the cutout portion of the column 1 contacts the joint fitting 30, and thus the displacement of the column 1 is restrained. Further, such a displacement as falling of the joint fitting 30 is also restrained.
(42) Thus, generation of the splitting at the lower end of the column 1 is controlled. Even if the splitting is generated, the column 1 is restrained from being displaced by a large amount. Thus, the resistance until breakage at the joint portion is improved, and displacement until breakage is controlled. Thus, safety of the structure is improved.
(43) The joint structure described above relates to joining the wooden column 1 to the foundation 3. However, as shown in
(44) In the structure for joining the upper end of the column 1 to the beam 2, a cutout portion 1d is provided in each of both ends in the longitudinal direction of an upper end face of the column 1, and the screw member 11 is threaded into the axial direction of the column 1 from inside the cutout portion 1d. In addition, the joint fitting 30 is coupled to the column 1 by the joint bolt 13 threaded into the screw member 11. Here, the same screw member 11, the joint bolt 13, the fastening nut 17, and the joint fitting 30 as those shown in
(45) A screw member 21 for beam is threaded into the beam 2 in the vertical direction at a position substantially on a same line as the screw member 11 threaded into the column 1. A screw hole is pierced in the axial direction from an end face of the screw member 21. Internal threads are cut on an inner peripheral surface of this screw hole, and a headless bolt 22 is threaded into this screw hole. Further, the headless bolt 22 is inserted into a bolt hole provided in the horizontal plate portion of the joint fitting 30, and a threadedly engaged fastening nut 23 is fastened such that the joint fitting 30 is fixed to the screw member 21 for beam threaded into the beam 2. In addition, using the screw member 21 for beam threaded into the beam 2, the column 7 of the upper floor may be joined on top of the beam 2 in a similar manner such that the bending moment is transmittable.
(46) With such a joint structure as well, similar to the case of joining the column 1 to the foundation 3, generation of the splitting in the column 1 by action of the shearing stress can be controlled. Even if the splitting is generated, a relative displacement of the column 1 with respect to the beam 2 can be controlled from becoming large.
(47)
(48) In this joint structure, similar to the one shown in
(49) As shown in
(50) On the one hand, this joint fitting 40 is fixed to the foundation 3 by the anchor bolt 12 embedded in the foundation 3, more particularly, the one joint fitting 40 is fixed by the two anchor bolts 12 arranged in the longitudinal direction of the column end face.
(51) In such a joint structure, as to the bending moment that acts on the lower end of the column 1, the tensile force is transmitted from, among the four screw members 11 and the four joint bolts 13 threaded into the screw members 11, the screw member 11 located on one end edge side in the longitudinal direction of the column end face to the joint fitting 40 via the joint bolt 13. Further, the tensile force is transmitted from the joint fitting 40 to the foundation 3. In addition, the compression force is transmitted from the screw member 11 located in the vicinity of the opposite end edge to the foundation 3 via the joint fitting 40.
(52) Further, the shearing force acts on the four screw members 11 and the four joint bolts 13 in a distributed manner such that the splitting of the column 1 is controlled. In addition, even if the splitting is generated along the screw member 11 on the end edge side, the shearing force is transmitted to the joint fitting 40 and the foundation 3 mainly by the screw member 11 and the joint bolt 13 threaded into the center side. Also, while a displacement at the lower end of the column 1 due to the shearing force is increased when the splitting of the column 1 is generated, the vertical surface 1b located inside the cutout portion of the column 1 contacts a side face of the joint fitting 40 fixed to the foundation 3 in a stable state by the two anchor bolts 12 to be restrained thereby. As a result, expansion of the displacement can be controlled.
(53) While the joint fitting 40 used in the present embodiment includes the back plate portion 45 as shown in
(54) The column end joint structure using such joint fittings 40, 50 may be applied to a structure for joining the upper end of the column to the beam or to a structure for joining the lower end of the column onto the beam, similarly to the joint structure shown in
(55) The joint fittings 40, 50 shown in
(56) The present invention is not limited to the embodiments described above, and may be embodied in other forms within the scope of the present invention.
(57) For example, a form of the joint bolt and a joining form of the joint bolt and the screw member may be in other forms such as a form in which a short joint bolt is threaded into a screw hole cut from the end face of the screw member. And, the joining form may be such that a rod-shape member having a hollow hole or a screw hole in the axial direction is embedded into the column and fixed by adhesive or the like, without employing the screw member. Further, the joining form may be such that a joint bolt coupled to a joint fitting is inserted into a hole provided in the axial direction of the column and the joint fitting is fixed by threadedly engaging a nut to a tip end portion inside an intermediate cutout portion provided in the column, without employing the screw member or the rod-shape member. Further, the sizes and the like of the column, the cutout portion of the column, and the joint fitting may also be arbitrarily designed, and shapes and the like of the foregoing may also be arbitrarily designed within the scope of the present invention.
(58) All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.
(59) The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) is to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising”, “having”, “including” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
(60) Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.
DESCRIPTION OF REFERENCE NUMERALS AND SYMBOLS
(61) 1: column 1a: cutout portion 1b: surface in axial direction of column inside cutout portion 1c: protruding portion of column end 1d: cutout portion 2: beam 3: foundation 3a: surface preparation material 4: base plate 5: elastic member 6: base 7: column of upper floor 10: Rahmen frame 11: screw member 11a: raised portion 11b: hollow hole 11c: internal thread 12: anchor bolt 13: joint bolt 14: flange portion of joint bolt 14a: recess portion provided in flange portion 15: front shaft portion of joint bolt 15a: tip-end external thread portion 16: rear shaft portion of joint bolt 16a: rear end external thread portion 16b: expanded diameter portion 17, 18: fastening nut 19: long screw 21: screw member for beam 22: headless bolt 23: fastening nut 30: joint fitting 30a: joint fitting arranged on a side closer to center of column 31: upper-side horizontal plate portion 32: lower-side horizontal plate portion 33: side plate portion 34: bolt hole 36: circular plate 37: oblong hole (long hole) 40: joint fitting 41: upper-side horizontal plate portion 42: lower-side horizontal plate portion 43: side plate portion 44: intermediate plate portion 45: back plate portion 46: bolt hole 50: joint fitting 51: upper-side horizontal plate portion 52: lower-side horizontal plate portion 53: side plate portion 54: intermediate plate portion 56: bolt hole