JPH0220764A - Construction method for square stressed concrete pole - Google Patents

Abstract

PURPOSE:To keep off any drop in an axial tension bearing capacity by installing a tension member in having it pierced through between opposite faces of a square steel pipe, removing a projecting part of the tension member after charging and solidification of concrete, and preventing any bulging of a skin plate from occurring. CONSTITUTION:A hole for piercing through a tension member 2 between both opposite faces of a square steel pipe 1 is bored at a required pitch P being conformed to internal pressure of charging concrete. Next, a rod with a double end screw as a tension member 2 is pierced through this through hole, and each butterfly nut 2 is clamped from both sides via a washer, thereby adding tension to a rod 2. Then, concrete is charged in the steel pipe 1. In addition, after the concrete is solidified, a projecting part to the outside of the tension member 2 is cut and removed and then a SC pole is erected.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of constructing a square SC column (a composite column of a square steel pipe and concrete).

[Prior Art] Many steel-framed reinforced concrete (SRC) columns have been used in the past as earthquake-resistant and fire-resistant structures, but the construction was complicated as it involved form work and reinforcing work.

Therefore, recently, attempts have been made to use SC columns that do not require formwork work.

[Problem to be Solved] However, in the case of a rectangular SC column with a large column diameter of several tens of meters in height, there is a problem that the steel pipe skin plate bulges due to the internal pressure of the concrete due to the press-in and filling of concrete.

When the skin plate swells, the column's ability to bear the axial force is significantly reduced, so some kind of solution is required.

[Means for Solving the Problems] The method for constructing a square SC column according to the present invention is to provide a tension member that prevents the steel pipe skin plate from bulging out between opposing faces of square steel pipes that are to be erected. After the concrete is filled and hardened, the protruding portion of the tension member is removed.

[Function] Since a tension member is provided between the facing sides of the square steel pipe,
It is possible to prevent the skin plate from bulging out due to the internal pressure of the concrete, and to prevent a decrease in the axial force bearing capacity.

Furthermore, since the tension member is provided to penetrate the steel pipe, the filling height during concrete filling can be monitored using this through hole. After construction, this through hole will function as a steam vent in the event of a fire.

[Example] Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

A hole through which a tension member is passed between the two faces of the square steel pipe 1,
The required pitch p is adjusted according to the internal pressure of the filled concrete.
I can open it. A rod with threads at both ends serving as a tension member 2 is passed through these through holes, and a wing nut 3 is tightened from both sides via washers to apply tension to the rod 2.

In this state, concrete is press-fitted or filled into the square steel pipe 1. In this case, even if the internal pressure of the concrete acts on the skin plate, the skin plate will not bulge out because the tension member 2 prevents the skin plate from bulging out. Furthermore, when press-fitting and filling concrete, the press-fitting and filling height can be monitored by checking the seepage of moisture from the through holes.

After the press-fitted and filled concrete has solidified, the protruding portion of the tension member 2 to the outside is cut and removed for fireproof covering work and finishing work.

In this way, it is possible to erect an SC column in which the steel pipe and concrete are integrated.

Furthermore, the two-legged through-hole functions as a steam vent in the event of a fire.

Note that the above embodiment has been described for the case where one tension member is provided for each height between facing steel pipes.
If the column diameter is large, a plurality of tension members 2 may be provided at the same height, as shown in FIG.

[Effect] The construction method of the rectangular SC column of this invention is as described above,
A simple method to prevent skin plate swelling,
It is possible to prevent a decrease in the axial force bearing capacity of the column.

In addition, the through-hole can be used to monitor the filling and press-in height of concrete, and after construction, the through-hole functions as a steam vent in the event of a fire.

[Brief explanation of the drawing]

1 and 2 are a plan view and a side view of a state in which tension members are attached, and FIG. 3 is a plan view when a plurality of tension members are attached at the same height. 1... Square steel pipe 2... Tension member Figure 1 Applicant's representative Patent attorney Takehiko Suzue Figure 2 Figure 3

Claims (1)

[Claims] A tension member is provided to prevent the steel pipe skin plate from bulging out between the opposing faces of the square steel pipes that are installed vertically,
A method of constructing a rectangular SC column, characterized in that the protruding portion of the tension member is removed after concrete is filled and solidified.