JP2009114662A - Concrete solid permanent sub-substructural column - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent sub-substructural column with a capability by which the construction of a ground skeleton can be started by inserting the permanent sub-substructural column into a pile even if an underground skeleton is multistory when a function of suppressing the deformation of the permanent sub-substructural column during a process of inserting the column into the pile is provided to the permanent sub-substructural column used in an inverted construction method. <P>SOLUTION: The permanent sub-substructural column 1 comprises a core 2 having a length obtained by adding the length for fixing to the pile 4 to the length of the all stories of the underground skeleton and a concrete 3 surrounding the district near a lower story among the districts excluding the fixing length of the core 2. A length equal to or longer than that of one story near the lower story of the underground skeleton is given to the concrete 3. The upper end side district of the core 2 is exposed from the concrete 3 by an amount of one or more story. The shape and size of the cross section of the concrete 3 are same as those of the column when the underground skeleton is completed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a concrete-integrated structural column that is used in a reverse driving method and that suppresses deformation in the insertion process.

  In the reverse striking method that inserts the construction pillar into the pile built in advance in the ground, discharges the earth and sand around the construction pillar after hardening the pile, and constructs the ground structure in parallel with the construction of the underground structure, In order to accurately insert the structural column into the pile, one of the problems is to suppress the inclination and deformation of the structural column during the insertion of the structural column.

  The verticality of the true pillar is ensured by adding a guide for insertion to a pedestal installed on the ground (see Patent Document 1), but as the full length of the true pillar increases, torsional rigidity and bending are increased. Since the rigidity is lowered and the structure is easily deformed, there is a limit to the length given to one structural column when the structural column is made of only a steel frame.

  If concrete is preliminarily integrated around the steel frame, it is possible to compensate for the lack of rigidity of the structural pillar (see Patent Documents 1 to 5). The length of one structural pillar is larger than that of the steel frame alone. It is possible to do.

JP-A-7-82892 (Claim 1, paragraphs 0004 and 0009, FIG. 1) JP 62-86242 A (Claim 1, FIG. 1, FIG. 2) JP-A-6-101244 (Claim 1, FIG. 1, FIG. 2) JP-A-8-68057 (Claim 1, paragraphs 0007 to 0008, FIG. 2) JP-A-8-296243 (Claim 1, paragraphs 0013 to 0023, FIGS. 1 and 2)

  However, as disclosed in Patent Document 1, a steel frame for insertion into a pile is embedded at the lower end of a concrete structural column having a length extending over multiple layers, and the upper end is connected to an underground frame or a ground frame beam. In a structure in which steel frames are embedded for joining, the pillars of the underground frame are reinforced concrete structures, so that it is not possible to have the same strength as a structure in which concrete is integrated around the steel frames (steel reinforced concrete structures).

  When the total length of the timber is made of steel and concrete as in Patent Documents 2 and 3, the column of the underground frame is made of steel reinforced concrete, and the proof strength of the column is improved from Patent Document 1, so It is possible to start the construction of the ground frame from the point when the pile is inserted and the strength of the pile is developed. On the other hand, since the mass per unit length of the structural pillar increases when the structural pillar spans multiple layers, the mass of a single structural pillar increases. It becomes difficult to give the column a length extending over a plurality of layers.

  The same applies to Patent Documents 4 and 5 in which a steel pipe is used as a steel frame and concrete is filled in the steel pipe. In these structural pillars, when the underground structure has two or more layers, it is difficult to construct the underground structural pillar by inserting only one structural pillar. I need it.

  In this way, if the total length of the structural column is made of steel-framed reinforced concrete, the strength of the column of the underground frame will increase, so that the structural column can be inserted into the pile and the construction of the ground frame can be started from the point when the pile is cured Although there is an advantage, there is an inconvenience that a structural pillar must be added when the underground structure spans multiple layers.

  In view of the above background, the present invention proposes a concrete-integrated concrete column having the ability to start construction of a ground frame by inserting a frame column into a pile even when the underground frame spans multiple layers.

The invention according to claim 1 is a built-up column used in a reverse driving method for building an underground frame while discharging the earth and sand around the built-up column after inserting the built-up column into a pre-built pile. And
A core material having a length obtained by adding a fixing length to the pile to the length of all layers of the underground frame;
Of the section excluding the fixing length of the core material, comprising concrete surrounding the section closer to the lower layer,
The concrete has a length of one layer or more near the lower layer of the underground frame,
The section on the upper end side of the core material is exposed to one layer or more from the concrete.

  The core material is a single steel frame or a combination of multiple steel frames, and the concrete is cast as precast concrete in a formwork assembled around the core material before the structural pillar is inserted into the ground. (Filled). The total length of the structural pillar is divided into a steel-framed reinforced concrete (SRC) section (concrete section) closer to the lower layer, and a steel-framed section (core exposed section) above it.

  The structure, form, and construction method of the piles are not limited, but they are constructed while forming excavation holes at the site, such as on-site creation piles and ground improvement piles, and piles with material fluidity are constructed immediately after construction. The pile does not complete the hardening until the steel frame protruding from the lower end of the structural pillar, that is, the lower end of the concrete, is inserted into the pile, and then hardens and exhibits a supporting force.

  Since the core material has the length of all layers of the underground frame, the concrete has a length of one layer or more, and the core material is exposed from the concrete by one layer or more, Corresponds to underground structures with a depth of at least two layers. The height (floor height) of each layer of the underground frame and the ground frame is not necessarily the same. For example, the floor height of each layer (each floor) of the underground frame may differ depending on the depth and usage.

  Since the section (concrete section) near the lower layer of the structural pillar is an SRC structure made of core material and concrete, the core material at the tip of the structural pillar is inserted into the pile, and the pile is cured. Since the section functions as a pillar of SRC structure, it is possible to bear the vertical load of the underground structure and the ground structure above it. For the concrete section, as in the case where the structural pillar is only a steel frame, the work of placing concrete around the structural pillar is not required after insertion.

  Although the section where the core material is exposed (core material exposed section) of the total length of the structural pillar is a steel frame, the core material is also exposed in the core material exposed section because the lower end of the structural pillar is supported by the pile. Since it has the ability to bear a vertical load within the loadable range, it is possible to start construction of the ground frame above the core material from the time when the built-up column is inserted into the pile and the pile is hardened. Therefore, it is not always necessary to wait for the construction of the ground frame until the concrete has been placed around the core. Until the concrete is placed around the core in the exposed area of the core material, the concrete of the structural pillar constrains the core material in that area, so the buckling length of the core material is set to the exposed area of the core material. The core material has a function of preventing the core material from bending and buckling due to the compressive load.

  Both the concrete section of the concrete pillar and the exposed section of the core have a certain vertical load bearing capacity, so that the structural pillar is at least the lower floor part of the ground frame when the pile develops bearing capacity due to hardening. Demonstrate the ability to bear the load of. For the lower floors of the ground frame, after the piles are hardened, construction of the ground frame on the ground starts, and concrete is placed in the core exposed section above the concrete section of the structural pillar. Until SRC is built, it refers to the floor of the ground frame that can be borne by the structural pillar (Figs. 3- (b) and (c)).

  If concrete is placed around the core in the exposed section of the core in parallel with the construction of the ground frame, the column of the underground frame can be completed, and then the column of the underground frame bears the total load of the ground frame Since it becomes possible (FIG. 3- (e)), construction of the ground frame is not interrupted until the ground frame is completed. After the underground pillars are completed, the underground pillars will be SRC, so the underground pillars have the ability to support high-rise ground.

  Although the concrete has a length of one layer or more near the lower layer of the core material, the core material is exposed from the concrete near the upper layer of the structural pillar, so that the total length of one structural pillar is longer than that of the SRC structure. Since the mass is reduced, it is possible to keep the mass within the lifting capacity of the hoisting machine while the structural column has the length of all layers of the underground frame. Inserting only one structural pillar per underground pillar into the underground will complete the insertion work, so there is no need to add the structural pillar, making construction more efficient than adding it. Is planned.

  As described above, the column of the underground frame is completed by placing concrete around the core material in the core material exposed section of the built-up column. Here, as described in claim 2, if the shape and size of the cross section of the concrete is the same as the shape and size of the cross section of the column when the underground frame is completed, the concrete around the core material is made to be concrete on the lower layer side (structure). It is possible to complete the pillar of the underground frame only by placing it until it hits the true pillar (concrete).

  In claim 2, since the concrete section of the structural pillar constitutes the pillar of the underground frame as it is, there is no need to lay concrete on the concrete section, so the concrete is placed around the core in the exposed core section. The pillar of the underground frame can be completed only by the installation.

  Further, in the second aspect, the concrete around the core material in the core material exposed section is independent of the concrete in the concrete section and is placed at the time of construction of the underground frame, so that the section closer to the upper layer of the construction pillar (core material) Since the section of the exposed section) can be given a section different from the concrete section in the concrete section, it is possible to meet the demand to make the section of the lower floor pillar of the underground frame different from the section of the upper floor pillar. Is possible.

  The structure column has a length that is the length of all layers of the underground frame plus the anchoring length to the pile, and the section of one layer or more closer to the lower layer of the total length is made of SRC. The upper section of one layer or more is a steel core, so that the total length of the steel frame is less than the SRC structure, while the steel structure section can bear the compressive force while reducing the mass of the column. You can start building.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a core material 2 having a length obtained by adding a fixed length to a pile 4 constructed in advance to the length of all layers of the underground frame, and a section excluding the fixed length of the core material 2. And a concrete 3 surrounding a section near the lower layer, the concrete 3 has a length of one layer or more near the lower layer of the underground frame, and a section on the upper end side of the core material 2 is one layer or more from the concrete 3 The construction example of the exposed concrete-integrated structural pillar (hereinafter referred to as the structural pillar) 1 and its construction state are shown.

  In FIG. 1 and subsequent figures, an example in which the underground frame has four layers (fourth floor) is described. However, the concrete pillar 1 has a length of concrete 3 longer than one layer of the underground frame, and the core material 2 has one layer. Since it is only necessary to be exposed from the concrete 3 or more minutes, the number of layers is not limited as long as the underground structure has two or more layers. In the drawing, concrete 3 has a length corresponding to two layers, core 2 is exposed from concrete 3 for two layers, and the number of layers in the section of concrete 3 and the exposed section of core 2 is equal. Yes.

  The floor height of each layer of the underground building is not necessarily the same. Corresponding to the usage of the 3rd to 4th floors and the 1st to 2nd floors in the drawing, the floor height of the 3rd to 4th basement (section of concrete 3) is 1st to 2nd floor (exposed section of core material 2). Although the floor height is smaller than the floor height, the floor heights of all the floors may be the same, or conversely, the floor heights of the third to fourth basements may be larger than the floor heights of the first and second basements. In the case shown in the drawing, the concrete pillar 1 is lighter than the case where the concrete 3 section and the core material 2 exposed section are equal because the section of the concrete 3 is shorter than the exposed section of the core material 2.

  The core material 2 is fixed to the pile 4 and has a length obtained by adding the length of all layers of the underground frame to the fixing length necessary to be supported. As shown in FIG. 1, the concrete 3 is the lowermost floor of the underground frame or the level of the foundation (bottom slab), or the vicinity thereof, and the length of the section from the vicinity to the floor level of the first floor or higher, or the vicinity thereof. Have The core material 2 apparently has a length to which a support length necessary for being supported by the gantry 5 at the time of inserting the structural pillar 1 is added, and this support length is secured by an attachment 21 described later.

  A protrusion 2 a for adhering to the pile 4 is formed or provided in a section of the core material 2 fixed to the pile 4. A rebar, a gibber, or the like is used for the protrusion 2a. An attachment 21 for suspending and supporting the entire construction pillar 1 is detachably connected to the upper end of the core material 2, and a receiving portion 21 a that is engaged with the gantry 5 is attached to a portion of the attachment 21 that is supported by the gantry 5. Is formed or protruded. An intermediate member in the lengthwise direction in the exposed section of the core material 2 is formed or protruded with a beam of an underground frame or a slab or the like, and a beam of the ground frame is formed at the upper end, or A joining member 2b for joining with a slab or the like is formed or provided.

  In the drawing, the concrete 3 is given the length from the lowermost floor, or the top of the foundation to the upper floor, the beam, or the capital (branch). From the lower end of the concrete 3, the column main reinforcement 3 a protrudes for fixing to the floor, the beam (capital), the foundation or the like of the lowermost layer. The upper end of the column main reinforcement 3a protrudes from the upper end of the concrete 3 due to the anchorage to the floor and beams (capital) of the intermediate floor of the underground frame. Alternatively, it is placed around the core material 2 and protrudes from the upper end of the concrete 3, which is fixed to the concrete constituting the columns 91 and 92 on the upper floor side of the underground frame. In the drawing, the underground structure is constructed with a flat slab structure consisting of columns and slabs, but the structure form of the underground structure is not limited.

  2- (a)-(e) demonstrates the insertion procedure to the underground of the stem pillar 1 in the ground. Prior to insertion of the true pillar 1, a pile 4 for supporting the lower end of the true pillar 1 is constructed. The pile 4 is formed by excavating the ground while excavating the earth 6 while forming the excavation hole 6 by earth drilling method, deep mixing processing method, etc., or by compacting the earth and sand to the surrounding ground of the excavation hole 6. It is constructed by supplying concrete, mortar, solidified material, etc. to the section. Before supplying concrete, mortar, or the like, a reinforcing bar, which is a tensile resistance material, may be inserted into the construction position of the pile 4 at the lower end of the excavation hole 6.

  FIG. 2- (a) shows a state when the construction pillar 1 is inserted after the pile 4 is constructed and before the pile 4 is hardened. When inserting the true pillar 1, a gantry 5 that supports the true pillar 1 is installed around the excavation hole 6 on the ground (on the ground surface). As shown in FIGS. 4A and 4B, the gantry 5 basically has a lower support member 51 assembled in the horizontal two directions on the ground or on the base plate 50, and an intermediate laid in two directions on the lower support member 51. It comprises a support member 52 and an upper support member 53 laid on the support member 52.

  Between the lower support member 51 and the intermediate support member 52, or between the intermediate support member 52 and the upper support member 53, the level of the upper support member 53 is secured, and the verticality of the structural pillar 1 is increased. A plurality of jacks 54 for securing are installed. The jack 54 and the intermediate part supporting member 52 secure the distance from the ground surface to the receiving part 21a of the attachment 21 so that the protruding length of the attachment 21 from the ground surface can be obtained when the stem column 1 is inserted, and the core is visually observed. It also has the role of making it easy to check the verticality of the material 2.

  As shown in FIG. 2- (a), the structural pillar 1 is suspended and supported by a lifting machine (not shown) and dropped into the center portion of the gantry 5 and is left as it is as shown in (b) to (d). It is gradually lowered while maintaining sex. Here, as shown in FIG. 4- (b), if the dimension of the inner periphery of the upper support member 53 in the two directions is set so as to enclose the concrete 3 exactly, the upper support member 53 is guided by the guide pillar 1. Therefore, the positioning work when the structural pillar 1 is lowered is facilitated, and the verticality during the descent is easily secured.

  The length of the attachment 21 and the protruding position of the receiving portion 21a are as shown in FIG. 2- (e). The core 2 protruding downward from the concrete 3 at the lower end of the construction pillar 1 is fixed in the pile 4. When the necessary section is inserted, the receiving portion 21 a is set to be locked to the upper support member 53 of the gantry 5.

  The structural pillar 1 is maintained in a state of being supported (locked) on the gantry 5 until the pile 4 is cured in the state of FIG. 2E in which the core material 2 is inserted into the pile 4. The construction after the pile 4 has hardened and exhibits the supporting force is performed according to the procedure shown in FIGS. After the pile 4 exhibits the supporting force, the structural pillar 1 is released from the support of the gantry 5. FIG. 3A shows a state in which the frame pillar 1 is separated from the gantry 5 and the attachment 21 is detached from the frame pillar 1.

  In the state of FIG. 3- (a), the upper end part of the core material 2 protrudes from the ground surface, and the joining member 2b of the part is exposed. From here, as shown in (b), construction of the ground frame is started, and as the progress proceeds, construction of the underground frame is performed toward the lower layer side. First, the bottom layer (for the first floor) pillars and beams (capital) of the ground frame are joined to the joining member 2b of the core member 2 protruding from the ground surface, and then the slab 71 of the floor is constructed.

  After the construction of the slab 71 at the bottom of the ground frame, or in parallel with the construction, pillars 81 and the like are constructed on the slab 71 as shown in (c) and (d). Under the slab 71, after excavating to the level of the slab 101 on the first basement floor, the slab 101 and the column 91 of the underground frame are constructed. The construction of the ground frame pillar 81 and the like and the construction of the underground frame are performed in parallel or before and after. At the time of discharging excavated soil, the slab 71 at the lowest layer on the ground frame serves as a cutting beam. In FIG. 3, a column 81 having a length corresponding to two layers of the ground frame is constructed according to the vertical load supporting ability of the structural pillar 1, and the slab 73 on the third floor is constructed at a time. There is also a case where the pillar 81 and the slab 72 (73) are constructed upward one floor at a time.

  On the basement side, following the construction of the slab 101, as shown in (e), construction of the pillar 91 on the first basement floor, construction of the slab 102 on the second basement floor, and construction of the pillar 92 on the second basement floor are performed. On the ground frame side, the building of the frame toward the upper layer side or around the pillar 81 is advanced in parallel. As described above, the concrete 3 of the structural pillar 1 in the drawing constitutes the 3rd to 4th floor pillars of the underground structure, so when the construction of the pillar 92 on the 2nd floor is completed, the construction of the pillars of the underground structure is completed. Ends.

  Thereafter, as shown in (f) and (g), the construction of the slab 103 on the third basement floor and the construction of the slab 104 on the fourth basement floor are performed on the underground building side. In the drawing, since the 4th basement floor is the lowest floor, the slab 104 on the bottom floor is constructed on the head of the pile 4 as a bottom plate thicker than the slabs 101 to 103 on the other floors. The slab 104 on the lowermost floor is constructed so as to be integrated with the pile 4 around the core material 2 exposed from the pile 4.

  On the ground frame side, after the construction of the slab 73 on the third floor above the ground, the pillar 82 on the upper floor is constructed, and the construction is further advanced toward the upper layer side. In the drawing, the construction of the slab 73 on the third floor is preceded by the height of the excavator carried on the ground surface before the construction of the underground structure is started. In this case, the construction of the slab 72 on the second floor is after the excavation to the surface of the slab 104 on the fourth floor is completed and the excavator is absent.

(A) is the elevation which showed the mode at the time of insertion to the true pillar of this invention, and its pile, (b) is the sectional view on the AA line of (a). (A)-(e) is an elevation view which showed a mode until a stem pillar was inserted in a pile. (A)-(g) is the elevation which showed the example of the procedure of the construction of an underground frame and a ground frame after inserting a stem pillar in a pile and hardening a pile. (A) is the elevation which showed the structural example of the mount frame, (b) is the top view of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Concrete-integrated structure pillar 2 ... Core material, 2a ... Protrusion, 2b ... Joining member 21 ... Attachment, 21a ... Receiving part 3 ... Concrete, 3a ... Column main reinforcement 4 ... Pile 5 ... Base: 51 ... Lower support member, 52 ... Intermediate support member, 53 ... Upper support member, 54 ... Jack, 50 ... Base plate 6 ... Drilling holes 71-73 ... Slab 81, 82 for ground frame …… Ground pillars 91, 92 …… Underground pillars 101-104 …… Underground slabs

Claims (2)

After inserting the structural pillar into the pile built in advance, it is a structural pillar used in the reverse driving method to construct the underground frame while discharging the earth and sand around the structural pillar,
A core material having a length obtained by adding a fixing length to the pile to the length of all layers of the underground frame;
Of the section excluding the fixing length of the core material, comprising concrete surrounding the section closer to the lower layer,
The concrete has a length of one layer or more near the lower layer of the underground frame,
A section of the upper end side of the core material is exposed from the concrete for one layer or more. 2. The concrete-integrated built-up column according to claim 1, wherein a shape and a size of a cross section of the concrete are the same as a shape and a size of a cross section of the column when the underground frame is completed.

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