JP2006188862A - Construction method of structure, and foundation structure used for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To propose a construction method of a structure, and a foundation structure suitably used for the construction method for constructing a skeleton abreast with the construction of the foundation structure. <P>SOLUTION: The construction method of the structure comprises processes of constructing a settlement reducing pile 20 in the ground, erecting a column 40 directly above the settlement reducing pile 20 through an intermediate member 30, constructing a spread foundation 10 joined to the column 40, and constructing an upper structure (skeleton) 2 using the column 40 abreast with the process of constructing the spread foundation 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a construction method for a structure in soft ground and a foundation structure suitably used for the method.

  Friction piles, etc. that are used for the ground where the bearing capacity can be satisfied by the direct foundation but which may cause harmful subsidence to the structure. A piled raft foundation that is used in combination with other subsidence reduction piles is known, for example, as shown in Patent Document 1.

Such a conventional piled raft foundation is to construct foundation members such as foundation slabs and foundation beams after constructing settlement settlement piles, and then construct a frame. In addition, these foundation members are generally constructed from on-site reinforced concrete.
Japanese Patent No. 3401567 ([0009]-[0014], FIGS. 1-2)

  Therefore, in a structure using a conventional piled raft foundation, after construction of settlement settlement piles, a series of operations such as reinforcement of the foundation structure, formwork installation, concrete placement, concrete curing, formwork dismantling, etc. are completed. Until then, construction of the frame could not be started, and the construction period was prolonged. In particular, when the frame is constructed using steel structures, precast members, etc., the period required for building the foundation structure is longer than the period required for building the frame, preventing the construction period from being shortened. It was.

  The present invention was made in order to solve such problems, and regarding the construction of a structure employing a piled raft foundation, a construction method for constructing a structure in parallel with the construction of the foundation structure It is an object of the present invention to propose a foundation structure suitably used for this.

  In order to solve the above problems, the present invention provides a process of constructing a settlement-reducing pile in the ground, a process of erecting a column directly above the settlement-reducing pile, and a frame using the installed pillar. And a method of constructing a structure including a step of constructing a direct foundation joined to the pillar, wherein the construction of the frame and the construction of the direct foundation are performed at the same time. It is a feature.

The construction method for such a structure is that the foundations are completed directly because it is possible to bear the load at the time of building the building by the settlement-reducing pile by standing the pillars that make up the structure directly above the settlement-reducing pile. Before, it becomes possible to proceed with the construction of the housing. Therefore, since it is possible to proceed directly with the foundation construction and the housing construction in parallel, the construction period can be greatly reduced. In addition, after the direct foundation is completed, the direct foundation supports the frame, and the settlement reduction piles reduce uneven settlement, and so a stable foundation structure is constructed. Here, the settlement settlement pile and the column are not joined together, but if the necessary degree of fixation is secured for the load during the construction until the foundation construction is completed directly Good.
“Establishing a column directly above a settlement-reducing pile” means that a column is erected in the axial direction of the settlement-reducing pile, and another member is interposed between the settlement-reducing pile and the column. The case where it does not do is included. Further, the “frame” indicates a main part of the structure such as a column, a beam, or a wall, and the material thereof is not limited.

  In addition, if the pillar is erected on the upper part of the settlement reduction pile via an intermediate member that constitutes at least a part of the direct foundation, the foundation constructed for the exposed column base is also used. It is possible to promote the construction of the frame before the structure is completed, which is preferable.

  In addition, if the intermediate member is a prefabricated member and constitutes the footing foundation of the structure, the footing foundation is completed simply by placing the prefabricated member on the settlement subsidence pile, enabling early construction. It is suitable. Moreover, the construction of the frame can be stably performed by the support force by the prefabricated member and the support force by the settlement reduction pile. Here, the prefabricated member refers to a member formed in advance in a predetermined shape by, for example, concrete or steel, and the material is not limited.

  Further, the present invention is a foundation structure comprising a direct foundation constructed so as to be able to support a structural frame, and a settlement reduction pile provided immediately below the pillar of the structural body to reduce the settlement of the structure. Thus, the pillar is mounted on the settlement reduction pile, and the settlement reduction pile bears a part of the load of the chassis at the time of building the chassis.

In such a foundation structure, the settlement reduction pile bears the load of the chassis, and the construction of the foundation and the chassis can be performed at the same time, so that the construction period can be greatly shortened.
Here, “directly under the pillar” is to construct a settlement reduction pile in the axial direction of the pillar, and includes cases where other members are interposed between the settlement reduction pile and the column.

  Further, if the pillar is mounted on the settlement settlement pile via an intermediate member constituting at least a part of the direct foundation, the construction of the structure by the exposed column base is also performed in parallel with the construction of the direct foundation. Thus, it is possible to construct a housing, which is preferable.

Here, if the subsidence reduction pile and the pillar or the intermediate member have a separable structure, the degree of fixation of the pile head is relaxed, and compared with the case where the pile head and the pile head are fixed, This is preferable because the acting bending moment is reduced. Thereby, the stress which generate | occur | produces in a foundation member is reduced, and reduction of the dimension of a foundation member, the amount of reinforcing bars, concrete strength, etc. is attained, and it is suitable.
Moreover, what is necessary is just to perform with respect to the pulling-out force of a housing | casing by a well-known method, such as resisting with an anchor bolt, an intermediate member, or the stud formed in the pillar.

  With the foundation structure of the present invention, regarding the construction of the structure adopting the piled raft foundation, it becomes possible to construct the frame in parallel with the construction of the foundation structure, and by the construction method of the structure using this foundation structure, The construction period required to construct the structure can be shortened.

  Preferred embodiments of the present invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.

<First Embodiment>
Fig.1 (a) is a front view which shows the whole structure based on 1st Embodiment, FIG.1 (b) is a top view which shows the basic structure based on 1st Embodiment. 2 is a sectional view showing a part of the foundation structure according to the first embodiment, and FIG. 3 is an exploded perspective view showing a part of the foundation structure of FIG. Moreover, Fig.4 (a)-(e) is sectional drawing which shows the construction procedure of the structure based on 1st Embodiment. Furthermore, Fig.5 (a)-(c) is a front view which shows the modification of the basic structure of 1st Embodiment.

  As shown in FIG. 1 (a), the structure 1 according to the first embodiment includes an upper structure 2 that is a casing of the structure 1, and a base structure 3 that supports the upper structure 2. A soft ground S2 having a small N value is deposited thickly under the surface support ground S1 having an N value of about 10 to 20, and a ground having a supporting ground S3 having an N value of 30 or more deeper than the soft ground S2. Since the structure 1 has a deep depth to the supporting ground S3, and the pile foundation type using the supporting pile has a large pile specification and is uneconomical, the direct foundation form (pile raft foundation) is adopted. Here, the upper structure 2 refers to a housing constructed on the foundation structure 3.

  The foundation structure 3 includes a direct foundation 10 constructed so as to be able to support the upper structure 2, and a settlement reduction pile 20 that is provided below the column 40 of the upper structure 2 in the axial direction to reduce the settlement of the structure 1. This is a so-called piled raft foundation, and a pillar 40 is mounted on the settlement settlement pile 20 via an intermediate member 30 (see FIG. 2).

  As shown in FIGS. 1A and 1B, the direct foundation 10 includes a plurality of (9 in the first embodiment) footings 11 arranged at predetermined positions with respect to the structure 1, and each footing 11. Each footing 11 is provided with one settlement-reducing pile 20. Here, in 1st Embodiment, although the continuous footing foundation comprised from the footing 11 and the foundation beam 12 was employ | adopted as the direct foundation 10, the form of the direct foundation 10 of the foundation structure 3 which concerns on this invention is limited. For example, a solid foundation or an independent footing foundation may be employed. Further, the number of footings 11 and the number of settlement reduction piles 20 are not limited, and are appropriately set according to the scale of the structure 1 and the ground condition.

The planar dimension of the footing 11 is large enough to obtain a sufficient ground support force 10a that can support the load transmitted from the structure 1 according to the ground constant such as the N value and shear strength of the surface support ground S1. Say it. In addition, when the surface support ground S1 is deep or when there is no clear surface support ground S1, the support ground is created artificially by improving the surface ground.
In addition, the specifications of the footing 11 and the foundation beam 12, such as the member dimensions, the amount of reinforcing bars, and the concrete strength, are determined in consideration of the effect on the stress generated in the foundation structure 3 of the settlement reduction pile 20 described later. A protruding portion having the same height as the upper surface of the foundation beam 12 is formed at a position corresponding to the central column 40 of the footing 11 with the intermediate member 30 disposed therein. Has a shape (so-called inverted T-shape) obtained by rotating a substantially T-shape up and down 180 ° (see FIG. 2).

  As shown in FIGS. 1 and 2, the settlement reduction pile 20 is made of a mixture of soil and cement in the local ground (hereinafter sometimes referred to as “soil cement”) 22 and a core material 21 such as H-shaped steel. A soil cement pile in which a steel material is arranged, the lower end of which has a length arranged in the soft ground S2, a circumferential friction force 20a between the circumferential surface of the settlement reduction pile 20 and the ground, and a tip support force This is a so-called friction pile that reduces the settlement of the structure 1 by 20b. The specifications such as the diameter, length, and arrangement interval of the settlement reduction pile 20 are determined by the prediction result of the settlement amount by an analysis method such as a finite element method in consideration of the ground conditions, the scale of the structure 1 and the construction process. . In the first embodiment, a soil cement pile is adopted as the settlement reduction pile 20, but the pile type of the settlement reduction pile 20 is not limited. For example, a ready-made concrete pile, a cast-in-place concrete pile, What is necessary is just to select suitably from well-known pile formats, such as a steel pipe pile and a steel pipe soil cement pile, and to employ | adopt.

  An upper end plate 23 made of a steel plate having the same shape as the specifications (web height, flange width) of the H-shaped steel constituting the core member 21 is integrally joined to the upper end of the core member 21 of the settlement reduction pile 20. Four mounting screws 25 project upward on the upper surface of the plate 23 (see FIG. 3).

  As shown in FIG. 2 or FIG. 3, the intermediate member 30 is made of a steel material in which an upper steel plate 32 made of a flat steel plate and a lower steel plate 33 are joined to upper and lower ends of a member body 31 made of H-shaped steel, and the footing 11 It has the same height as the total thickness of the foundation beam 12. Further, as the H-section steel constituting the member main body 31, the specifications (web height, flange width) equivalent to the specifications of the square steel pipe constituting the column 40 are used. Moreover, the steel material which comprises the main body member 31 is not limited to H-section steel, What is necessary is just to select and employ | adopt suitably from well-known steel materials, for example using a square steel pipe.

  As shown in FIG. 3, a convex portion 34 formed in a cross shape in a plan view is formed at the center of the upper surface (surface on the column 40 side) of the upper steel plate 32, and the lower end of the column 40 and the intermediate member 30 are formed. The installation area with the upper end of the column is reduced, and the column 40 is rotatably mounted. Here, the shape dimension of the convex part 34 should just have the width | variety, thickness, and shape which can stand the pillar 40 vertically with respect to the construction error of the settlement reduction pile 20, and is cross-shaped. It is not limited. Moreover, the material of the convex part 34 will not be limited if it has sufficient proof stress with respect to the mounting load loaded on the intermediate member 30. FIG.

  Further, two joining screws 35 for joining to the pillars 40 protrude upward on the upper surface of the convex portion 34. In the first embodiment, the joining screw 35 is formed by welding to the upper surface of the convex portion 34. However, the joining screw 35 may be formed by a bolt penetrating the upper steel plate 32 and the hole penetrating the convex portion 34, etc. The method for forming the screw 35 is not limited.

  Moreover, the bolt hole 37 is penetrated by the predetermined position in the lower steel plate 33, and the attachment screw 25 formed in the upper end of the settlement reduction pile 20 is formed so that insertion is possible.

  As shown in FIG. 3, a base plate 42 made of a rectangular steel plate having a width larger than the width of the column main body 41 is integrally joined to the column 40 at the lower end of a column main body 41 made of a square steel pipe. Bolt holes 47 are formed at positions corresponding to the joining screws 35 of the intermediate member 30 of the base plate 42. The base plate 42 is formed with four anchor holes 44 on the outer side of the column main body 41, and the anchor 45 directly embedded in the foundation 10 and resists the pulling force of the upper structure 2 passes through the anchor hole 44. The nut 46 is fixed by being fastened. In addition, an opening 43 is formed at the lower end of the column main body 41 so that a tool or the like can be inserted in order to screw the nut 36 into the joining screw 35 inserted through the bolt hole 47. Here, the arrangement, specifications, and the like of the anchor 45 and the joining screw 35 are appropriately determined according to the degree of fixation expected for the column base, the magnitude of the extraction force, and the like. Here, the length of the anchor 45 disposed in the footing 11 is set to a length that can secure fixing that exhibits sufficient resistance against the pulling force acting on the column 40.

Then, the construction method of the structure 1 is demonstrated with reference to FIG.
The structure 1 is joined to the column 40, a first step of constructing the settlement subsidence pile 20 in the ground, a second step of standing the column 40 directly above the settlement subsidence pile 20 via the intermediate member 30, and It is constructed by a third process for constructing the foundation 10 directly and a fourth process for constructing the upper structure 2 using the upright pillars 40.

[First step]
First, as shown to Fig.4 (a), the subsidence reduction pile 20 and the intermediate member 30 are arrange | positioned by the well-known construction method directly under the location where the pillar 40 of the structure 1 is going to stand. At this time, the settlement reduction pile 20 is constructed so that the upper end thereof protrudes slightly from the flooring surface 14 of the foundation 10 directly. Moreover, the circumference | surroundings of the settlement reduction pile 20 are excavated directly to the flooring surface 14 of the foundation 10 so that the construction is possible. The intermediate member 30 is installed at the upper end of the settlement reduction pile 20 after the settlement reduction pile 20 is installed at a predetermined position even if the intermediate member 30 is installed at the upper end of the settlement reduction pile 20 in advance at the time of construction of the settlement reduction pile 20. May be. In addition, the intermediate member 30 is joined to the settlement reduction pile 20 after being suspended so that the mounting screw 25 of the settlement reduction pile 20 is inserted into the bolt hole 37 of the intermediate member 30 from above the settlement reduction pile 20. This is done by fastening with a nut 24 (see FIG. 3).

[Second step]
Subsequently, as illustrated in FIG. 4B, the column 40 is joined to the upper end of the intermediate member 30. The pillar 40 is joined to the intermediate member 30 from above the intermediate member 30 by a lifting machine such as a crane so that the joining screw 35 of the intermediate member 30 is inserted into the bolt hole 47 (see FIG. 3) of the base plate 42. After suspending by a not-shown), the nut 36 is used for fastening. At this time, even if the settlement reduction pile 20 is inclined at the time of construction, the column 40 is erected vertically by rotating the lower end of the column 40 using the convex portion 34 of the intermediate member 30. In addition, in 1st Embodiment, although the adjustment at the time of the construction of the pillar 40 shall be performed in the upper end of the intermediate member 30, by forming a convex part in the upper end of the settlement reduction pile 20, of the settlement reduction pile 20 is demonstrated. It may be performed at the upper end.

[Third step]
When the joining of the column 40 to the intermediate member 30 is completed, the foundation 10 is directly constructed in parallel with the construction of the upper structure 2. As shown in FIG. 4 (c), the direct foundation 10 is constructed by first performing a flooring operation for expanding the ground around the intermediate member 30 to the extent that the footing 11 can be constructed. In addition, ground work such as shingle gravel 15 and discarded concrete to improve the familiarity between the lower surface of the footing 11 and the ground is performed.

  Next, after placing reinforcements and formwork (not shown) of the footing 11, concrete placement is performed to construct the footing 11. At this time, the anchor 45 having a length that can secure a predetermined fixing length in the footing 11 is fixed to the base plate 42 (see FIG. 4D). In the first embodiment, the tip of the anchor 45 is hooked in order to fix the anchor 45 inside the footing 11 having a limited thickness.

  In the first embodiment, the footing 11 is constructed in two stages. First, concrete is placed to the lower surface of the foundation beam 12 to construct the lower part of the footing 11, and the footing immediately below the remaining pillar 40. As for the construction of the upper part of 11, it will be performed simultaneously with the concrete placement of the foundation beam 12. By performing construction according to this procedure, it becomes possible to omit a part of the formwork of the footing 11 and to simplify the reinforcement work of the foundation beam 12. Needless to say, the footing 11 may be completed by placing concrete around the intermediate member 30 at this stage.

After curing the lower part of the footing 11, as shown in FIG. 4D, the formwork is removed and the dug portion around the footing 11 is refilled. Then, the reinforcing bars 13 of the foundation beam 12 are arranged and a formwork (not shown) is installed, and then concrete is placed to construct the foundation beam 12.
When the construction of the foundation beam 12 is completed, as shown in FIG. 4E, the base mortar 16 is filled in the gap between the intermediate member 30 and the column 40 formed by the convex portion 34, thereby directly 10 and the column 40 are joined.

[Fourth process]
When the pillar 40 is erected on the upper end of the intermediate member 30, the construction of the upper structure 2 is continuously started using the pillar 40 before the foundation 10 is directly completed.

  As described above, the structure 1 according to the first embodiment waits for the foundation 10 to be completed directly in order to mount the column 40 on the settlement-reducing pile 20 via the intermediate member 30 after constructing the settlement-reducing pile 20. Therefore, it is possible to start construction of the upper structure 2 without performing the construction of the upper structure 2 in parallel with construction of the foundation 10 directly. That is, by supporting the supporting force at the time of construction of the superstructure 2 until the foundation 10 is completed directly by the peripheral friction force 20a and the tip supporting force 20b of the settlement reduction pile 20, without waiting for the completion of the foundation 10 directly. Construction of the superstructure 2 can be started. Moreover, since the settlement reduction pile 20 and the column 40 (intermediate member 30) are simply joined by the mounting bolt 25, safety against the sliding force associated with the construction of the upper structure 2 is also ensured.

  Further, the mounting screw 25 used for installing the intermediate member 30 on the upper end of the settlement reducing pile 20 should have a strength necessary for a load during construction of the superstructure 2 until the foundation 10 is completed directly. When an additional stress such as an earthquake after the construction of the structure 1 is applied, the mounting screw 25 yields and the foundation 10 and the settlement reduction pile 20 are separated directly. The bending moment acting on the joint is reduced. Therefore, since the stress which generate | occur | produces in the assumed direct foundation 10 is reduced, the reduction | decrease of the dimension of the direct foundation 10, a reinforcement amount, concrete strength, etc. is attained, and it is suitable. Note that the horizontal displacement during an earthquake or the like is reduced by the frictional resistance of the bottom surface of the footing 11.

In addition, since the foundation structure 3 can directly reduce the size of the foundation 10, the excavation depth becomes shallow accordingly, and the amount of excavated soil can be reduced.
Moreover, since the uneven settlement of the structure 1 is reduced by the settlement reduction pile 20, the safety of the structure 1 is also excellent.

Moreover, since the upper structure 2 is joined to the foundation structure 3 via the anchors 45, the upper structure 2 has a sufficient resistance against the pulling-out force of the column base generated due to the horizontal amount during an earthquake or the like. In addition, since the bending moment generated at the joint of the column base is also processed by the foundation beam 12, the structure 1 having excellent safety is constructed.
Moreover, since the joining of the upper structure 2 and the intermediate member 30 (direct foundation 10) is not integrally fixed, but joined in a state close to pin joining, transmission of bending moment is reduced, Damage to the column base and direct foundation 10 is prevented.

  The joining method and specifications of the intermediate member 30 are not limited to those described above, and may be set as appropriate. For example, as shown in FIG. 5A, a joining screw 35 ′ protrudes downward from the base plate 42 of the column 40, and a bolt hole (not shown) corresponding to the joining screw 35 ′ is formed in the upper steel plate 32 of the intermediate member 30. By forming the joining screw 35 'of the column 40 from above into the bolt hole of the intermediate member 30, the fastening screw 35 may be fastened to the upper steel plate 32 by the nut 36 on the lower surface. The direction of is not limited. Similarly, the direction of the mounting screw 25 used for joining the intermediate member 30 and the settlement reduction pile 20 is not limited, and may be set according to the situation as appropriate. Needless to say, a bolt may be used instead of the mounting screw 25 and the joining screw 35.

Further, as shown in FIG. 5 (b), by using a steel plate having a wide width as the upper steel plate 32 of the intermediate member 30, the joining screw is fastened outside the column main body 41. Fastening work becomes easy and workability is improved.
Moreover, the joining method of the settlement reduction pile 20 and the intermediate member 30 is not limited to the method using the attachment screw 25. For example, an H-section steel that constitutes a part of the settlement reduction pile 20 is a predetermined shape. The length (for example, about the foundation height) is protruded from the pile head, and the flange of the protruding portion of this H-shaped steel is cut from the pile head by a predetermined length (for example, 10 cm). It is good also as a structure which relieve | rotates the rotational rigidity of a pile head, transmitting axial force by carrying out thickening reinforcement.

  In addition, when the settlement reduction pile 20 is an off-the-shelf pile, a process that can be attached to the pile head, such as welding an attachment screw 25 to an end plate of the pile head of the settlement reduction pile 20 suffices. Similarly, when a cast-in-place pile is adopted as a settlement reduction pile, a process such as placing an anchor for a mounting screw on the pile head may be performed.

Second Embodiment
6 is a sectional view showing a part of the foundation structure according to the second embodiment, and FIG. 7 is an exploded perspective view showing a part of the foundation structure of FIG. Moreover, Fig.8 (a), (b) is a front view which shows the modification of the basic structure of 2nd Embodiment.

  In the second embodiment, in the structure 1 shown in FIG. 1A, the bending moment generated in the column base of the upper structure 2 is smaller than that in the structure shown in the first embodiment, and this bending moment is processed by the footing 11. Since it is possible, the structure 1 in which the foundation beam 12 is omitted will be described.

  As shown in FIG. 6, the foundation structure 3 according to the second embodiment is provided directly below the foundation 10 constructed to support the upper structure 2 and the column 40 of the upper structure 2 in the axial direction. 1 is a so-called piled raft foundation composed of a subsidence reduction pile 20 that reduces subsidence, and a pillar 40 is mounted on the subsidence reduction pile 20 via an intermediate member 30.

  As shown in FIGS. 1A and 1B, the direct foundation 10 is configured by a plurality of (9 places in the second embodiment) footings 11 arranged at predetermined positions with respect to the structure 1. Each footing 11 is provided with a settlement reduction pile 20. Here, in 2nd Embodiment, although the independent footing foundation comprised by the footing 11 was employ | adopted as the direct foundation 10, the form of the direct foundation 10 of the foundation structure 3 which concerns on this invention is not limited. For example, a solid foundation may be employed.

The details of the footing 11 are the same as the contents shown in the first embodiment, and thus detailed description thereof is omitted. In the second embodiment, since the height of the intermediate member 30 is the same as the height of the footing 11, the cross-sectional shape of the footing 11 does not have a protruding portion as shown in FIG. Is formed. Here, the cross-sectional shape of the footing 11 is not limited. For example, the upper surface of the footing 11 has a taper that decreases in the outward direction from directly below the pillar 40, so that a trapezoid is placed in a rectangular shape. It may be formed in a hexagonal shape.
Moreover, since the same thing as the content shown in 1st Embodiment is used also about the settlement reduction pile 20, detailed description is abbreviate | omitted.

  As shown in FIG. 6 or 7, the intermediate member 30 is made of a steel material in which an upper steel plate 32 made of a flat steel plate and a lower steel plate 33 are joined to upper and lower ends of a member main body 31 made of H-shaped steel. It has the same height as the total thickness. Further, as the H-section steel constituting the member main body 31, the specifications (web height, flange width) equivalent to the specifications of the square steel pipe constituting the column 40 are used. Moreover, the steel material which comprises the main body member 31 is not limited to H-section steel, What is necessary is just to select and employ | adopt suitably from well-known steel materials, for example using a square steel pipe.

  A plurality of studs 38 (6 in each surface in the second embodiment) are formed on the side surface (outer surface of the flange) of the intermediate member 30 to resist the pulling force acting on the column 40. The degree of fixing with the footing 11 is increased.

  As shown in FIG. 7, a convex portion 34 formed in a cross shape is formed at the center of the upper surface (surface on the column 40 side) of the upper steel plate 32, and the lower end of the column 40 and the upper end of the intermediate member 30 are The installation area is reduced, and the column 40 is rotatably mounted. Here, the shape dimension of the convex part 34 should just have the width | variety, thickness, and shape which can stand the pillar 40 vertically with respect to the construction error of the settlement reduction pile 20, and is cross-shaped. It is not limited. Moreover, the material of the convex part 34 will not be limited if it has sufficient proof stress with respect to the mounting load loaded on the intermediate member 30. FIG.

  Further, four joining screws 35 for joining to the pillars 40 protrude upward on the upper surface of the convex portion 34. In the second embodiment, the joining screw 35 is formed by welding to the upper surface of the convex portion 34. However, a hole penetrating the upper steel plate 32 and the convex portion 34 is formed, and a bolt is inserted into the hole. The forming method of the joining screw 35 is not limited, for example, by forming. Further, the arrangement, specifications, and the like of the joining screw 35 are appropriately determined according to the degree of fixation expected for the column base, the magnitude of the pulling force, and the like.

  Moreover, the bolt hole 37 is penetrated by the predetermined position in the lower steel plate 33, and the attachment screw 25 formed in the upper end of the settlement reduction pile 20 is formed so that insertion is possible.

  As shown in FIG. 7, a base plate 42 made of a rectangular steel plate having a width slightly larger than the width of the column main body 41 is integrally joined to the column 40 at the lower end of a column main body 41 made of a square steel pipe. Bolt holes 47 are formed at positions corresponding to the joining screws 35 of the intermediate member 30 of the base plate 42. In addition, an opening 43 is formed at the lower end of the column main body 41 so that a tool or the like can be inserted in order to screw the nut 36 into the joining screw 35 inserted through the bolt hole 47.

  The construction method of the structure 1 according to the second embodiment includes a first step of constructing the settlement-reducing pile 20 in the ground, and a second method in which the column 40 is erected directly above the settlement-reducing pile 20 via the intermediate member 30. It is constructed by a process, a third process of constructing the direct foundation 10 joined to the pillar 40, and a fourth process of constructing the upper structure 2 using the pillar 40 installed upright. The construction method of the structure 1 according to the second embodiment is the same as the procedure shown in the first embodiment except that the construction of the foundation beam and the installation of the anchor in the third step are not required. Description is omitted.

  As described above, in the structure 1 according to the second embodiment, the extraction transmission bolt is provided on the intermediate member 30 in which the stud 38 that exhibits sufficient resistance against the extraction force of the column 40 acting on the column base is formed. Since it is joined via the (joining screw 35), the column base pulling force generated with the horizontal amount during an earthquake or the like is transmitted to the intermediate member by the joining screw 35 and resists. In addition, since the bending moment generated at the joint of the column base is also processed by the foundation beam 12, the structure 1 having excellent safety is constructed.

  Moreover, since the structure 1 which concerns on 2nd Embodiment constructs the settlement reduction pile 20 at the time of the construction, in order to mount the pillar 40 on the settlement settlement pile 20 via the intermediate member 30, the foundation 10 is directly completed. The construction of the upper structure 2 can be started without waiting, and the construction period can be greatly shortened by performing the construction of the upper structure 2 in parallel with the construction of the foundation 10 directly. That is, by supporting the supporting force at the time of construction of the superstructure 2 until the foundation 10 is completed directly by the peripheral friction force 20a and the tip supporting force 20b of the settlement reduction pile 20, without waiting for the completion of the foundation 10 directly. Construction of the superstructure 2 can be started. Moreover, since the settlement reduction pile 20 and the column 40 (intermediate member 30) are simply joined by the mounting bolt 25, safety against the sliding force associated with the construction of the upper structure 2 is also ensured.

  In addition, since the other effect of the structure 1 concerning 2nd Embodiment is the same as that of what was shown in 1st Embodiment, detailed description is abbreviate | omitted.

In addition, the joining method and specification of the intermediate member 30 according to the second embodiment are not limited to those described above, and may be set as appropriate. For example, as shown in FIG. 8A, a configuration may be adopted in which a pulling force is processed by the lower steel plate 33 and the stud 38 by using a wide steel plate as the lower steel plate 33 of the intermediate member 30.
Further, as shown in FIG. 8B, the lower steel plate 33 and the stud 38 are arranged by arranging the stud 38 on the lower lower steel plate 33 so that the protruding member is arranged upward around the member main body 31. It is good also as a structure which processes drawing force by.

<Third Embodiment>
3rd Embodiment demonstrates the case where the structure 1 shown in 1st Embodiment and 2nd Embodiment was constructed | assembled without using the intermediate member 30 by using the column 40 of the upper structure 2 as an embedded column base. Here, FIG. 9 is sectional drawing which shows the foundation structure 3 of 3rd Embodiment, (a) is based on a continuous footing foundation, (b) shows based on an independent footing foundation.

  As shown in FIG. 9A, the foundation structure 3 according to the third embodiment is provided below the direct foundation 10 constructed to support the upper structure 2 and the column 40 of the upper structure 2 in the axial direction. This is a so-called piled raft foundation composed of a settlement reduction pile 20 for reducing the settlement of the structure 1, and a pillar 40 is directly mounted on the settlement reduction pile 20.

  As shown in FIGS. 1A and 1B, the direct foundation 10 is configured by nine footings 11 arranged at predetermined positions with respect to the structure 1 and foundation beams 12 connecting the footings 11. Each footing 11 is provided with a settlement reduction pile 20. In addition, the number of the footings 11 shall be suitably set according to the scale of the structure 1 and the ground condition, and is not limited to nine places.

Here, since the structure of the direct foundation 10 is the same as the content shown in 1st Embodiment, detailed description is abbreviate | omitted.
Moreover, since it is the same as that of the content shown in 1st Embodiment also about the structure of the settlement reduction pile 20, detailed description is abbreviate | omitted.

  As shown in FIG. 9A, the column 40 is integrally joined to a lower end of a column main body 41 made of a rectangular steel pipe and a base plate 42 made of a rectangular steel plate having a width approximately equal to the width of the column main body 41. The base plate 42 is similarly formed with bolt holes at positions corresponding to the mounting screws 25 of the settlement reduction pile 20.

In addition, studs 45 are formed at a predetermined pitch on the outer peripheral surface of the portion embedded directly in the foundation 10 of the column 40, so that the structure can resist the pulling force acting on the column base.
In addition, the length of the pillar 40 is the length of one floor, and an erection piece (not shown) is installed on the upper side surface of the pillar 40 to adjust the inclination and the like when joining to the pillar 40 on the upper floor. .

  Since the construction method of the structure 1 according to the third embodiment is the same as that of the first embodiment except for the arrangement of the intermediate members, detailed description thereof is omitted.

  As described above, in the structure 1 according to the third embodiment, since a plurality of studs 25 are formed at a predetermined pitch on the outer periphery of the portion embedded directly in the foundation 10 of the column 40, the horizontal amount during an earthquake or the like can be obtained. It has sufficient resistance against the pull-out force of the column base. In addition, since the bending moment generated at the joint of the column base is also processed by the foundation beam 12, the structure 1 having excellent safety is constructed.

Moreover, since the structure 1 which concerns on 3rd Embodiment constructs the settlement reduction pile 20 at the time of the construction, in order to mount the pillar 40 on this settlement reduction pile 20, it is superstructure without waiting for completion of the foundation 10 directly. 2 can be started, and the construction period can be greatly shortened by constructing the upper structure 2 in parallel with the construction of the foundation 10 directly. That is, by supporting the supporting force at the time of construction of the superstructure 2 until the foundation 10 is completed directly by the peripheral friction force 20a and the tip supporting force 20b of the settlement reduction pile 20, without waiting for the completion of the foundation 10 directly. Construction of the superstructure 2 can be started. Moreover, since the settlement reduction pile 20 and the column 40 are simply joined by the mounting bolt 25, safety against the sliding force associated with the construction of the upper structure 2 is also ensured.
Since the other functions and effects are the same as those described in the first embodiment, detailed description thereof is omitted.

  The structure 1 according to the third embodiment can be applied to an independent footing foundation not having the foundation beam 12 as shown in FIG. 9B, for example, and the foundation structure is not limited. .

<Fourth embodiment>
4th Embodiment demonstrates the case where a prefabricated member is used as the footing 11 about construction | assembly of the structure 1 shown to Fig.1 (a).
Here, FIG. 10 is a cross-sectional view showing a part of the basic structure according to the fourth embodiment, where (a) shows the case of continuous footing and (b) shows the case of independent footing. 11A to 11D are a cross-sectional view and a plan view showing a construction procedure of the foundation structure of the fourth embodiment. Further, FIGS. 12A to 12D are diagrams showing a modification of the footing of the fourth embodiment, and FIGS. 13A to 13D also show a modification of the footing of the fourth embodiment. FIG.

  As shown in FIG. 10A, the foundation structure 3 according to the fourth embodiment is provided directly below the foundation 10 constructed so as to support the upper structure 2 and the column 40 of the upper structure 2 in the axial direction. This is a so-called piled raft foundation constituted by a settlement reduction pile 20 for reducing the settlement of the structure 1, and a precast concrete member (prefabricated member) is used as the footing 11 directly constituting the foundation 10.

  As shown in FIG. 10A, the direct foundation 10 is composed of a footing 11 made of a precast concrete member and a foundation beam 12 made of cast-in-place concrete that connects the footings 11. The settlement reduction pile 20 is disposed. Here, in 4th Embodiment, although the continuous footing foundation comprised from the footing foundation 11 and the foundation beam 12 was employ | adopted as the direct foundation 10, the form of the direct foundation 10 of the foundation structure 3 which concerns on this invention is For example, an independent footing foundation that does not have a foundation beam, such as a foundation structure 3 ′ shown in FIG. 10B, may be adopted.

  The planar dimension of the footing 11 is large enough to obtain a sufficient ground support force 10a that can support the load transmitted from the structure 1 according to the ground constant such as the N value and shear strength of the surface support ground S1. Say it. In addition, when the surface layer support ground S1 is deep, or when there is clearly no surface layer support ground S1, the support ground is artificially created by performing ground improvement on the surface layer ground.

  In addition, the specifications of the footing 11 and the foundation beam 12 such as the member dimensions, the amount of reinforcing bars, and the concrete strength are determined in consideration of the effect on the stress generated in the foundation structure 3 of the settlement reduction pile 20 described later. As shown in FIG. 10A, an anchor 45 for attaching the column 40 is embedded in the footing 11 in a state where its upper end protrudes in advance, and the cross-sectional shape of the footing 11 is directly below the column 40. , A protruding portion having the same height as the upper surface of the foundation beam 12 is formed, and is formed into a shape (so-called inverted T shape) obtained by rotating a substantially T-shape up and down by 180 °. Here, the cross-sectional shape of the footing 11 is not limited, and may be formed in a rectangular shape, for example, as shown in FIG. In addition, the length of the anchor 45 arranged in the footing 11 is set to a length that can secure fixing that exhibits a sufficient resistance against the pulling force acting on the column 40.

  The subsidence reduction pile 20 uses the same thing as what was shown in 1st Embodiment, and abbreviate | omits detailed description. In addition, although the footing 11 only mounts on the upper end of the settlement reduction pile 20, the contact surface of the footing 11 and the settlement reduction pile 20 is not joined, but between the footing 11 and the settlement reduction pile 20 as needed. An anti-slip anchor or the like may be arranged.

  As shown in FIG. 10A, the column 40 is integrally joined to a lower end of a column main body 41 made of a square steel pipe and a base plate 42 made of a rectangular steel plate having a width larger than the width of the column main body 41. The base plate 42 is formed with four anchor holes (not shown) outside the column main body 41. An anchor 45 is embedded in a position corresponding to the anchor hole of the base plate 42 of the footing 11 with its upper end protruding in advance, and this protruding portion is inserted into the anchor hole and fastened with a nut 46. Thus, the footing 11 and the column 40 are joined. Note that the method of joining the column 40 and the footing 11 is not limited to the method using an anchor. For example, as shown in FIG. 10B, the attachment member 45 ′ is embedded in the footing 11 in advance. An appropriate method may be selected as appropriate, such as fixing the base plate 42 of the column 40 to the mounting member 45 ′.

Then, the construction method of the structure 1 which concerns on 4th Embodiment is demonstrated with reference to FIG.
Such a structure 1 includes a first step of constructing a settlement-reducing pile 20 in the ground, a second step of placing a footing 11 made of a precast concrete member directly on the settlement-reducing pile 20, and an intermediate member above the footing 11. A third step of erecting the column 40 through 30, a fourth step of constructing the direct foundation 10 joined to the column 40, and a fifth step of constructing the upper structure 2 using the erect column 40 Built by the process.

[First step]
First, as shown to Fig.11 (a), the settlement reduction pile 20 is arrange | positioned by the well-known construction method directly under the location where the pillar 40 of the structure 1 is going to stand. At this time, the subsidence reduction pile 20 is constructed so that the upper end thereof is positioned directly above the flooring surface of the foundation 10 and on the thickness of the concrete 17 and the laid gravel 15. Moreover, the circumference | surroundings of the settlement reduction pile 20 are excavated directly to the flooring surface 14 of the foundation 10 so that the construction is possible.

[Second step]
Next, the excavation surface is widened so that the footing 11 can be placed around the upper end of the settlement reduction pile 20, and flooring work is performed, and the bottom surface of the footing 11 and the ground are made to conform to the floor mounting surface. For this purpose, groundwork such as shingle gravel 15 and discarded concrete 17 is performed (see FIG. 11B).
Then, as shown in FIG. 11C, the footing 11 is placed on the upper end of the settlement reduction pile 20.

[Third step]
Subsequently, as shown in FIG. 11 (d), the column 40 is joined to the upper end of the footing 11. The pillar 40 is joined to the footing 11 from above the footing 11 by a lifting machine (not shown) such as a crane so that the protruding portion of the anchor 45 embedded in the footing 11 is inserted into the anchor hole of the base plate 42. After being suspended by, the nut 46 is tightened.

[Fourth process]
When the joining of the column 40 to the footing 11 is completed, the foundation beam 11 is constructed in parallel with the construction of the upper structure 2. Construction of the foundation beam 12 is performed by first arranging reinforcing bars and installing a formwork (not shown) and then placing concrete (see FIG. 11 (d)).

[Fifth step]
When the pillar 40 is erected on the upper end of the intermediate member 30, the construction of the upper structure 2 is continuously started using the pillar 40 before the foundation 10 is directly completed.

  As described above, in the structure 1 according to the fourth embodiment, after the subsidence reduction pile 20 is constructed, the precast footing 11 is installed, and the column 40 is erected via the footing 11. Therefore, it is possible to start the construction of the upper structure 2 without waiting for the completion of the direct foundation 10, and if the construction of the upper structure 2 is performed in parallel with the construction of the direct foundation 10, the construction period can be greatly shortened. It becomes possible. That is, by supporting the supporting force at the time of construction of the superstructure 2 until the foundation 10 is completed directly by the peripheral friction force 20a and the tip supporting force 20b of the settlement reduction pile 20, without waiting for the completion of the foundation 10 directly. Construction of the superstructure 2 can be started.

  Moreover, since the settlement reduction pile 20 and the direct foundation 10 are not integrally coupled, the stress generated in the direct foundation 10 is reduced, and the dimensions, the amount of reinforcing bars, and the concrete strength of the foundation 10 can be directly reduced. Is preferable. Note that the horizontal displacement during an earthquake or the like is reduced by the frictional resistance of the bottom surface of the footing 11.

Further, since the foundation structure 3 can directly reduce the dimensions of the foundation 10, the excavation depth becomes shallow accordingly, and the amount of excavated soil can be reduced.
Moreover, since the uneven settlement of the structure 1 is reduced by the settlement reduction pile, the safety of the structure is also excellent.

  Moreover, since the upper structure 2 is joined to the foundation structure 3 via the anchors 45, the upper structure 2 has a sufficient resistance against the pulling-out force of the column base generated due to the horizontal amount during an earthquake or the like. In addition, since the bending moment generated at the joint of the column base is also processed by the foundation beam 12, the structure 1 having excellent safety is constructed.

  In the fourth embodiment, a prefabricated member that has been formed in advance is used as the footing 11. However, when the footing 11 is large and difficult to transport, the footing 11 is used as the footing 11. For example, as shown in FIGS. 12A and 12B, only the portion corresponding to the settlement reduction pile 20 and the column 40 is used as a prefabricated member 11a, and the remaining portion is footed by spotting. 11 may be constructed. In this case, construction of the on-site hit portion 11b is performed in parallel with the construction of the upper structure 2 constructed via the prefabricated member 11a, thereby shortening the construction period.

  Further, as shown in FIGS. 12C and 12D, the prefabricated member 11a is made only at the lower end of the footing 11 and the remaining portion is made on-site, thereby reducing the weight of the prefabricated member 11a and making it easy to convey. It may be.

  Further, as shown in FIGS. 13A and 13B and FIGS. 13C and 13D, the footing 11 is divided into a plurality of parts such as three or four, thereby transporting the prefabricated footing 11. It is good also as a structure which enables this.

As mentioned above, although preferred embodiment was described about this invention, this invention is not limited to the said embodiment, A design change is possible suitably in the range which does not deviate from the meaning of this invention.
For example, the subsidence reduction pile and the intermediate member, column, or footing may be joined to the foundation until the foundation is completed. You may isolate | separate by removing a mounting screw after completion.

Moreover, in each said embodiment, although it was set as the structure which bears the load of the housing of the ground part of a structure as a housing which a subsidence reduction pile bears a load during construction, when a structure has a housing also in an underground part It goes without saying that the settlement settlement piles also bear a part of the load of the underground frame.
Moreover, the structure which can apply the foundation structure which concerns on this invention is not limited to a building, It can apply as a foundation of all structures.
In the fourth embodiment, a precast concrete member is used as the prefabricated member. However, for example, a steel member may be used, and the material of the prefabricated member is not limited.

(A) is a front view which shows the whole structure concerning 1st Embodiment, (b) is a top view which shows the basic structure which concerns on 1st Embodiment. It is sectional drawing which shows a part of foundation structure concerning 1st Embodiment. It is a disassembled perspective view which shows a part of foundation structure of FIG. (A)-(e) is sectional drawing which shows the construction procedure of the foundation structure of 1st Embodiment. (A)-(c) is a front view which shows the modification of the basic structure of 1st Embodiment. It is sectional drawing which shows a part of foundation structure concerning 2nd Embodiment. It is a disassembled perspective view which shows a part of foundation structure of FIG. (A), (b) is a front view which shows the modification of the basic structure of 2nd Embodiment. It is sectional drawing which shows the foundation structure 3 of 3rd Embodiment, Comprising: (a) is based on a continuous footing foundation, (b) shows based on an independent footing foundation. It is sectional drawing which shows a part of foundation structure concerning 4th Embodiment, (a) is a continuous footing, (b) shows the case of an independent footing. (A)-(d) is sectional drawing which shows the construction procedure of the foundation structure of 4th Embodiment. (A), (c) is a sectional side view which shows the modification of the footing of 4th Embodiment, (b), (d) is the same top view. (A), (c) is a sectional side view which shows the modification of the footing of 4th Embodiment, (b), (d) is the same top view.

Explanation of symbols

1 Structure 2 Superstructure (Housing)
3 foundation structure 10 direct foundation 11 footing 12 foundation beam 20 settlement settlement pile 30 intermediate member 40 pillar S1 surface ground S2 soft ground

Claims (5)

A process of constructing subsidence reduction piles in the ground;
A step of erecting a column directly above the settlement settlement pile;
A step of constructing a frame using the standing pillar;
Constructing a direct foundation joined to the pillar, and a method of constructing the structure,
The construction method for a structure, wherein the construction of the frame and the construction of the direct foundation are performed at the same time.   The method for constructing a structure according to claim 1, wherein the column is erected on an upper portion of the settlement reduction pile via an intermediate member that constitutes at least a part of the direct foundation.   The construction method for a structure according to claim 2, wherein the intermediate member is a footing-based prefabricated member. A direct foundation constructed so as to be able to support the structural frame; and a settlement-reducing pile provided directly below the pillar of the structural body to reduce the settlement of the structural structure,
A foundation structure in which the pillar is mounted on the settlement-reducing pile, and the settlement-reducing pile bears a part of the load of the chassis at the time of building the chassis.   The foundation structure according to claim 4, wherein the pillar is mounted on the settlement reduction pile via an intermediate member constituting at least a part of the direct foundation.

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