JPH0684686B2 - Standing method for precast concrete columns - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method of standing precast concrete columns for making the concrete columns self-supporting when constructing a multi-storey building.

(Prior Art) Conventionally, a method has been developed in which a precast concrete column is erected, and a precast concrete beam is rigidly connected to this to sequentially construct a multi-storey building. In this type of conventional method, a method of standing a precast concrete column on an existing concrete foundation, inserting a PC steel material from the concrete foundation into the precast concrete column, and fixing the PC steel material at the upper end of the precast concrete column by tension fixing Has been taken.

(Problems to be solved by the invention) In such a conventional standing method of a precast concrete column, the precast concrete column is hoisted vertically and installed at a predetermined position, and a diagonal member is pulled from three or more directions. There is a problem that the diagonal member is an obstacle because it makes it self-supporting, inserts the PC steel material and is tensioned, then hangs the beam horizontally and stabilizes it, and then removes the diagonal member, which deteriorates workability. .

As a solution to such a problem, it is conceivable to temporarily bolt precast concrete columns to make them self-supporting, but if a recessed portion for bolting is provided in the precast concrete columns, that part becomes weaker due to cross-section loss. However, in order to prevent this, it is necessary to make the whole precast concrete column thick so that sufficient strength can be obtained even if a cross-section defect occurs, which is a problem of being uneconomical.

In view of such a problem, the present invention does not cause a problem in the strength of the precast concrete column even if the concave portion for bolting is formed. Therefore, it is not necessary to make the entire precast concrete column thick, and the provisional bolt The purpose is to provide a method of standing precast concrete columns that can be stopped and can be constructed without the need for diagonal members for self-standing.

(Means for Solving the Problem) The feature of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose is that a precast concrete column is erected on the existing concrete structure part constructed earlier. , In the standing method of the precast concrete column to insert the PC steel material continuously to the precast concrete column and the existing concrete structure part, to tension the PC steel material and integrate the existing concrete structure part and the precast concrete column, On the side surface of the lowest floor of the precast concrete column, the concave portion is provided at the inflection point position of the bending moment due to the vertical load applied to the beam connected to the precast concrete column, and from the concave portion to the lower end surface. Temporary installation by opening a temporary steel material insertion hole continuously and projecting from the preceding concrete structure into the hole Steel inserted through the screwed nut at the steel material of the tip in the recessed portion is temporarily fixed, and then inserting the PC steel in tension caused Sarukoto.

(Operation) In a precast concrete column that is erected by this method, when a beam is laid across it to form a rigid gate structure, the precast concrete column when the recessed portion for temporary fixing is subjected to vertical load It is at the inflection point of the bending moment applied to the pillar, and since no bending moment occurs at this position,
Even if a cross-section loss occurs, the strength does not decrease under a vertical load.

(Example) Next, an example of an embodiment of the present invention will be described with reference to the drawings. First, at the construction site, by a conventional method, the foundation concrete 1 which is an existing concrete structure portion for erecting the precast concrete columns is placed. This foundation concrete 1
, The pillar connecting steel materials 2, 2 ... and the PC steel materials 3, 3 for prestressing are embedded and fitted to the lower ends, and these are projected to the upper end surface.

Next, the pedestal block 4 is installed on the foundation concrete 1. The pedestal block 4 has a PC steel material 3 in its square portion,
Further, steel material through-holes 5, 5, ... For penetrating the column-connecting steel materials 2, respectively, are pre-opened inside the central portions of the four sides, and the respective steel materials 2, 3 are made to penetrate through the respective holes 5.

When installing the pedestal block 4, the pedestal block 4 is hoisted horizontally, the steel materials 2 and 3 are inserted into the holes 5 and lowered, the liner is laid on the foundation concrete 1, and the high-strength mortar 6 is laid in layers. , Adjust the level and install it with the top surface horizontal.

The precast concrete pillars 7 are erected on the pedestal block 4 thus installed. This pillar 7 is made by integrally molding in advance to a length of about two floors of the building, and a concave portion 8 is formed in each central portion of the four faces around the lower end portion thereof, and the concave portion is formed. A connecting steel material insertion hole 9 is formed from 8 to the lower end surface.

As shown in FIG. 4, when the girder 17, which will be described later, is erected to form a rigid structure, the concave portion 8 is
It is formed at a position that is the inflection point A of the bending moment due to the vertical load.

On the other hand, the square portion of the pillar 7 is vertically penetrated through the PC steel material insertion hole 10
Is formed, and a diameter-expanded portion 10a formed by a coupler sheath is formed at the lower end of the hole 10.

In this way, the steel materials 2 and 3 described above are inserted into the insertion holes 9 and 10 formed in the pillar 7 and the pillar 7 is erected on the pedestal block 4. Prior to this, the pedestal block 4 A strong epoxy resin adhesive is applied to the upper surface, and a coupler joint 11 is screwed onto the upper end of the PC steel material 3. In this way, the pillar 7 is lifted to stand.

In addition, the PC steel material insertion hole 10 of the pillar 7 is preliminarily inserted with the PC steel material 13 from the upper end, and the nut 14 is screwed to the upper end so as to be suspended in the hole 10, and then the pillar 7 is lifted to pedestal block. 4 Stand vertically by hanging it up. Then, the column 7 is fixed by screwing and tightening the nut 15 onto the connecting steel material 2 in the recessed portion 8, and the PC steel material 13 is swung from the upper end of the column 7 and the lower end thereof is screwed into the coupler joint 11. Then, both PC steel materials 3 and 13 are integrated.

After that, the PC steel material 13 is pulled from the upper end by a jack, and the end portion is fixed to the upper surface of the column 7 to give prestress. As a result, the pillar 7, the pedestal block 4, and the foundation concrete 1 have a cantilever structure that is mechanically integrated.

The girder receiving projection 16 is integrally formed in advance at a desired height position around the concrete pillar 7 which is erected in this way, and the end of the girder 17 is supported on the projection 16 to support the pillar 7. It will be installed between 7 and 7.

Further, the connection between the pillar 7 and the girder 17 is made by, for example, as shown in FIG. 5, a connecting portion 18 is projected on the lower surface of the end of the girder 17, and the connecting portion 18 and the pillar 7 are penetrated to form a PC steel material. Insert 19a and 19b, and fix it with tension at the end.

In addition, in the above-mentioned Example, although the case where the precast concrete pillar 7 is erected on the foundation concrete 1 is shown, in addition to this, the existing concrete structure part which erected the precast concrete pillar 7 is It may be a concrete pillar.

(Effect of the invention) As described above, in the standing method of the precast concrete pillar of the present invention, the precast concrete pillar is provided with the recessed portion for fixing the temporary fixing bolt, and the precast concrete pillar is fixed in the recessed portion. As a result, the pillar can be made to be self-supporting without using a tilt for tilting and the workability is improved, and the position of the recess for temporary fixing is the bending of the bending moment due to vertical load. Since it is located at the point position, there is no structural problem even if the strength is reduced due to the lack of cross section, and the structure can be constructed economically.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a vertical cross-sectional view of a pedestal block in an installed state, FIG. 2 is a plan view of the same, and FIG. 3 is a partially omitted cross-sectional view of a pillar in an upright state. FIG. 4 is a bending moment diagram with respect to a vertical load, and FIG. 5 is a partially omitted enlarged sectional view showing a connected state of a girder. 1 ... Foundation concrete, 4 ... Pedestal block, 6 ... High-strength mortar, 7 ... Column, 11 ... Coupler joint, 16 ... Large beam receiving projection, 17 ... Large beam, A ... Inflection point.

Claims (1)

[Claims] 1. A precast concrete column is erected on an existing concrete structure part constructed earlier, the precast concrete column and the existing concrete structure part are continuously inserted with a PC steel material, and the PC steel material is tensioned and installed. In a method of standing a precast concrete column that integrates a concrete structure part and a precast concrete column, in a side surface of a lowermost floor portion of the precast concrete column, by a vertical load applied to a beam connected to the precast concrete column. A concave portion is provided at a position opposite to the bending moment of the bending moment, and a temporary steel material insertion hole is formed continuously from the concave portion to the lower end surface, and the temporary steel material projecting from the preceding concrete structure is inserted into the hole. , A nut is screwed into the tip of the steel material in the recess to temporarily fix it, and then the PC steel material Stand 設方 method of precast concrete pillars made as characterized in that the insertion and, to tension.