JPH073063B2 - Construction method of steel true pillar in reverse driving method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a method of erection of a true steel column in a reverse driving method applied to foundation construction of a high-rise building.

[Prior art]

The construction method of the steel true pillar in the reverse driving method has been conventionally performed by using various methods, but generally, a jig using Yatco is installed on the ground near the excavation hole and connected on the ground. The steel true pillar and Yatco are inserted into the excavation hole through a jig and suspended by a crane, held in place by the jig, and the sand around the steel true pillar is backfilled with rough sand, gravel, etc. After hardening, the worker enters the excavation hole, removes the bolt connecting the steel true column and the yatco, and then recovers the yatco.

[Problems to be Solved by the Invention]

Therefore, in the conventional steel pillar building method,
It takes time and effort to insert the steel true pillar into the drill hole, and when removing the Yatco joined to the steel true pillar, the worker enters the drill hole and performs the work, which is dangerous and requires work. There was a problem that the efficiency was lowered.

[Means to solve the problem]

In order to solve the problems of the conventional steel true-column erection method in the reverse driving method of the present invention, the steel true-column erection method was assembled in a cross beam shape at the upper end of the stand pipe inserted into the drill hole. A gantry is installed, steel true columns are hung in this excavation hole, and after temporarily placing it on the gantry, Yatco is lifted and placed at the upper end of the steel true column temporarily placed on the gantry and the lower end of the Yatco. The integrated steel true columns and Yatco are hung as they are in the excavation hole as they are, and the steel true columns are inserted into the specified positions of the concrete, and the concrete After the hardening, the gist is that the engaging device is operated from the ground to separate the steel true pillar and the yatco so that the yatco is collected.

〔Example〕

In order to prevent the collapse of the ground near the surface layer of the excavation hole B by excavating the excavation hole B, which is a pile hole of the required search, by the reverse construction method and the earth construction method in the cast-in-place pile construction method. The stand pipe (or surface layer casing) A is inserted along the inner peripheral surface of the excavation hole. And even if a load is applied to the stand pipe A, the stand pipe A
The settling prevention bracket 4 is welded to the outer peripheral surface of the stand pipe A so that the required grounding pressure can be obtained so that the settling does not settle, and the bracket 4 is grounded to the ground to install the stand pipe A.

Further, on the upper part of the stand pipe A, as shown in FIGS. 7 and 8, a gantry 3 having I-beams 6 assembled in a cross beam shape is installed. When assembling this I-beam 6, each I-beam
The Bulman jig 7 shown in FIG. 9 is used to connect between the 6 and 6, that is, between the I beams 6 and 6 that intersect with each other. Like this 4
1 beam 6 of the book is assembled in a cross beam shape, and the pedestal 3 is lightened and easily assembled by the connection with the Bullman jig 7.
The Bulman jig 7 is used to reduce the weight of the gantry 3 and to easily assemble and disassemble it.

In addition, the lower surface of the lower I-beam 6 assembled in the shape of a cross beam has a fifth
As shown in FIG. 7 and FIG. 7, the gantry mounting jig 5 is arranged, and the gantry mounting jig 5 and the I-beam 6 are coupled by the Bulman jig 7. The gantry mounting jig 5 includes a plate 51 extending along the lower surface of the I-beam 6 and a sandwiching piece 5 vertically installed to face the lower surface.
2, 53, and the upper end of the stand pipe A is inserted between the two sandwiching pieces 52, 53 facing each other, and a fixing bolt 5 is attached to one or both of the sandwiching pieces 52, 53.
4, 55 are screwed together, and the gantry mounting jig 5 is fixed to the stand pipe A by fastening the bolts 54, 55. In this way, the cross-shaped mount 3 is fixed on the stand pipe A through the mount mounting jig 5 and the Bullman jig 7,
The steel true pillar 1 is built in the excavation hole B using this mount 3.

As shown in detail in FIG. 1, the steel true pillar 1 has a required diameter and length, and its lower end is embedded in the upper portion of the concrete pile D placed in the excavation hole B. Further, the upper end is closed by the upper steel plate 8, and the inside is airtight.

Then, four bolt holes 9a are preliminarily drilled in the upper steel plate 8 of the steel true pillar 1, a nut 9 having the same hole as the bolt hole 9a is welded to the lower surface of the upper steel plate 8, and the box cover 10 is welded. It is watertight so that water does not enter the inside of the true column 1 through the bolt hole 9a.

When this steel true pillar 1 is built in the excavation hole B, FIG.
The Yatco 2 shown in the figure is used. The Yatco 2 is detachably mounted on the upper part of the steel true pillar 1. The structure of this Yatco 2 is an I-beam 21 having the same shape as the steel true pillar 1 as a spindle and four rods at its upper end. A Yatco steel plate 11 having a pipe insertion hole 13 is welded thereto, and a Yatco lower steel plate 12 having a bolt hole 9a into which four special engagement bolts 14 can be inserted is welded to the lower end thereof to obtain a Yatco upper steel plate 11 A hanging metal fitting 15 is welded to the upper end of the center of the to form a frame.

The engagement device E used for engaging the steel true pole 1 and the yanko 2 is arranged along the longitudinal direction of the yanko 2 as shown in detail in FIG. 3 and FIG. And the engaging bolt 19. A circular nut 17 having the same shape as the rod pipe 16 having a lever insertion hole 17a is welded to the upper end of the rod pipe 16, and a special engagement bolt 14 can be detachably fitted to the lower end of the rod pipe 16. The engagement box 18 thus formed is welded, and bolt holes 19a into which the engagement bolts 19 can be easily inserted are formed on both side surfaces of the engagement box 18, and the special engagement bolt 14 is formed by the nut 2
0, the insertion hole 20a of the engagement bolt 19 and the threaded portion 21, and the threaded portion 21 of the special engagement bolt 14 is screwed into the nut 9 previously welded to the lower surface of the upper steel plate 8 of the steel true pillar 1. With the engagement bolt 19, the bolt insertion hole 19a of the engagement box 18 and the bolt insertion hole 20a of the special engagement bolt 14 are penetrated to connect the upper steel plate 8 of the steel true pillar 1 to the steel plate 12 of the bottom moat Then
The upper end of the rod pipe 16 is inserted into a rod pipe insertion hole 13 provided in the upper steel plate of the Yatco 11 to be integrated.

Next, a method for building a steel true pillar using the steel true pillar, the gantry, and the Yatco configured as described above will be described.

First, after placing concrete in the excavation hole B, the pedestal 3 is placed on the stand pipe A while the concrete is not yet hardened.
, The steel true pole 1 is inserted into the excavation hole B by a crane, and the Yatco 2 is lifted after being temporarily placed on the pedestal 3, and the upper steel plate 8 and the Yatco lower steel plate 12 of the steel true pole 1 are lifted. , The special engagement bolt 14 is screwed into the nut 9 of the upper steel plate 8 and the engagement box 18 welded to the lower end of the rod pipe 16 is fitted and inserted.
The steel plate 8 and the lower steel plate 12 of the steel true pillar 1 are connected to each other by penetrating the steel true pillar 1 to be integrated, and the integrated steel true pillar 1 and the yatco 2 are suspended in the drill hole B as they are by a crane. Lower it and insert the steel true pillar 1 into the specified position of the placed concrete, and let the bracket 22 of the Yatco 2 stand still on the upper end of the height-adjusted small jack 23 arranged on the pedestal 3, The insertion of the pillar 1 is completed.

After the concrete is hardened, it is backfilled to the upper end of the steel true pillar 1 using rough sand or the like, and then the engaging device E is operated from the ground, that is, the lever hole 17a provided at the upper end of the rod pipe 16 is leveraged. When the rod pipe 16 is inserted and the rod pipe 16 is rotated in the reverse direction, the special engagement bolt 14 is disengaged from the nut 9 provided on the lower surface of the upper steel plate 8 of the steel true pillar 1 to separate the steel true pillar 1 from the yatco 2 and the yatco 2 Is picked up by a crane and collected.

〔The invention's effect〕

As described above, the present invention has the above-described configuration, and therefore has the following effects.

Since the I-beam is assembled on the standpipe in a cross beam shape to form a gantry, the assembly is easy and a special jig is not required to be manufactured. Therefore, the manufacturing cost, the transportation cost, etc. are reduced.

Since the steel true pillar and Yatco are separately connected on the hoisting stand, work can be performed even with a small crane having a short boom.

After inserting the steel true pillar, the yatco can be collected by operation on the ground, so that safety and work efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view of a steel true column of the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a sectional view of Yatco, FIG. 4 is a plan view of the same, and FIG. FIG. 6 is an explanatory view of an engaging device for engaging the steel true pillar and the Yatco, FIG. 7 is an explanatory view of the gantry assembly, and FIG.
FIG. 9 is a plan view of the gantry, and FIG. 9 is an explanatory view of the Bullman jig. A is a stand pipe, B is a drill hole, C is a stabilizing liquid, D is a concrete pile, E is an engaging jig, D1 is a steel true pillar, 2 is a Yatco, 21 is an I beam, 3 is a pedestal, 4 is settling prevention Bracket, 5 is a frame mounting jig, 6 is an I-beam, 7 is a Bullman jig, 8 is an upper steel plate, 9 is a bolt nut, 9a is a bolt hole,
10 is a box cover, 11 is a Yatco upper steel plate, 12 is a Yatco lower steel plate, 13 is a rod pipe insertion hole, 14 is a special engagement bolt, 15 is a hanging fitting, 16 is a rod pipe, 17 is a circular nut, and 17a is Lever insertion hole, 18 is engagement hole, 19 is engagement bolt, 19a is bolt insertion hole, 20 is nut, 20a is bolt insertion hole, 21 is threaded portion, 22 is bracket, 23 is small jack

Claims (1)

[Claims] 1. A gantry assembled in the shape of a cross girder is installed on the upper end of a stand pipe inserted into an excavation hole, a steel true pillar is suspended in this excavation hole, and the tentacle is lifted after being temporarily placed on the gantry. , The upper ends of the steel true columns temporarily placed on the gantry and the lower ends of the yatcoes are connected to each other through an engagement device to be integrated, and the integrated steel true columns and the yatco are directly in the drill hole. Then, the steel true pillar is inserted into a predetermined position of the cast concrete, and after the concrete hardens, the engaging device is operated from the ground to separate the steel true pillar and the yatco, and the yatco is collected. The construction method of steel true columns in the reverse driving method characterized by the above.