KR100977526B1 - Small dia. pile and constructure method for it - Google Patents

Abstract

PURPOSE: A small-diameter pile using a CFT is provided to increase frictional force between a steel pipe and mortar using a friction supporting and reinforcing unit. CONSTITUTION: A small-diameter pile using a CFT comprises a CFT pile(102) and friction supporting and reinforcing unit. The CFT pile is formed by filling a steel pipe with concrete. The friction supporting and reinforcing unit is attached on the outer surface of the CFT pile embedded in a rock layer. The friction supporting and reinforcing unit is composed of steel wires or reinforcing bars(103).

Description

Small-diameter file using CFC {SMALL DIA. PILE AND CONSTRUCTURE METHOD FOR IT}

The present invention relates to a small-diameter pile using a CFT, and more particularly, to a small-diameter pile using a CFT that can provide a small-diameter CFT usable in indoor construction, etc., and to increase frictional force outside the steel pipe.

The redevelopment and reconstruction of buildings may lead to poor urban living environment due to overcrowding, and it is in the stage of reconsideration as it wastes resources and unnecessary construction wastes by demolishing and reconstructing earlier than the building's own life.

In addition, in the past, it is now in the stage of selective volume rate adjustment, so that the new building needs to be recycled, to rebuild existing buildings, to increase asset value, and to increase the unit household area. There is a search for a way to create a structural form.

In view of the foregoing, some areas where reconstruction and redevelopment are nearing their limits have pointed out that the remodeling of buildings should be activated rather than reconstruction in the future. In other words, in case of multi-unit housing, there is no land for redevelopment and reconstruction, and environmental destruction and waste of resources are caused by redevelopment and reconstruction. Therefore, housing policy needs to turn to remodeling.

In particular, in modern life, cars have become an indispensable means of transportation, and at least one car, two generations of cars, which are means of transportation for each household, is presently causing serious parking shortages.

Therefore, there was a need for underground reinforcement work in order to construct a two-story or more underground parking lot in the basement of an existing building due to the parking shortage as described above.

On the other hand, if you look at the conventional underground reinforcement construction method, after drilling the ground to a certain diameter, the pillars are erected and the base concrete is made at the lower end of the pillar.

However, when the outer surface of the pillar in contact with the foundation concrete is smooth, the main surface friction of the pillar to the foundation concrete after curing is reduced, especially the factor that weakens the bearing capacity of the pile when the pillar is used in the place of the pile supporting the building Becomes

In order to solve the above problems, 10-1994-0005547 discloses a projection steel pipe pile method that can reinforce the main surface friction by forming a projection on the steel pipe pile by a hydraulic jack.

However, in the case of the patent, the use of Oga as the equipment for drilling the ground, this Oga equipment is a large equipment, it is impossible to construct in the interior construction of the narrow space and low floor.

The present invention has been made in view of the above point, to produce a small diameter CFT that can be used for indoor construction, and to weld the wire or reinforcing steel outside the small diameter CFT in advance to increase the friction performance between the steel pipe and the surrounding mortar. The purpose of the present invention is to provide a small diameter file using a CFT.

The above object is a small diameter file using a CFT,

CFT pile embedded in the ground and rock layers to a certain depth, filled with concrete in the steel pipe; And friction support reinforcement means attached to an outer surface of the CFT pile embedded in the rock layer, wherein concrete is poured on the outer surface of the CFT pile, and frictional force between the CFT steel pipe and the surrounding concrete is provided through the friction support reinforcement means. It is achieved by a small diameter pile using a CFT, characterized in that the pile is frictionally supported by the rock layer.

Preferably, the friction support reinforcing means is a steel wire or reinforcing bar, characterized in that the steel wire or reinforcing bar is welded to the outer surface of the CFT pile.

In addition, the CFT file is characterized in that it has a small diameter of the size that can be drilled by small drilling equipment usable in indoor construction.

According to another embodiment of the present invention, a cross plate is attached to the bottom inner diameter surface of the CFT pile to protrude, and the cross plate protruding from the bottom of the CFT file is characterized in that the front end is supported on the rock layer before concrete casting.

In addition, the cross-shaped surface is characterized in that the studs are vertically attached at regular intervals.

Accordingly, according to the small-diameter file and the construction method using the CFT according to the present invention, by producing a small-diameter file, and drilled through the hole of the small-diameter with a small equipment to work even in indoor construction with a narrow place and low floor height There are possible advantages.

In addition, by using a small-diameter CFT pile filled with high-strength concrete in the steel pipe, it can withstand the high load of the building, and by increasing the frictional force between the steel pipe and the surrounding concrete by welding steel wire or reinforcing steel outside.

In addition, since the lower end of the steel pipe is frictionally supported by the weathered rock (rock layer), there is an advantage that the main surface support is excellent.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a small diameter file using a CFT and a construction method thereof, and in particular, to provide a small diameter CFT file that can be used in indoor construction, and to pre-processing and welding a steel wire or reinforcing steel outside the steel pipe in a circular shape, The present invention relates to a small-diameter pile and a construction method using the CFT with improved frictional performance.

In general, the pile (PILE) refers to a pillar that is embedded in the ground to support the building, the pile is embedded in a rock bed (weathered rock) to a certain depth to secure the support of the foundation ground, if the pile is classified according to the material , Wood piles, concrete piles, reinforced concrete piles, prestressed concrete piles, steel piles, etc., and classified according to the nature of the pile, divided into support piles and friction piles. The support pile means that the tip of the pile reaches and supports the hard ground, and the friction pile supports the load by the surrounding ground, pile and frictional force.

However, large-scale equipment cannot be used in narrow construction and low-floor indoor construction, so small equipment should be used. Among the small equipments, the equipment used in the indoor construction is a drill of the small diameter drilling equipment.

Here, the present invention has a structure that resists the high-strength force of the building using a concrete-filled steel tube (CFT) column filled with concrete in the steel pipe as the material of the pile, in particular, after drilling with a chroma drill in indoor construction Small-diameter CFT pile is used to improve the friction performance between steel pipe and surrounding mortar by processing and welding steel wire or reinforcing bar on the outside of steel pipe.

Moreover, the CFT structure can secure rigidity and strength by filling high-strength concrete inside the steel pipe, not only has strong properties such as deformation and buckling, but also shows excellent performance in various aspects such as fire resistance and construction, and thus is very excellent as a structural material. Has

Hereinafter, the small-diameter file 102 and the construction method using the CFT according to the first embodiment of the present invention will be described. 1 is a perspective view illustrating a small diameter CFT file according to an embodiment of the present invention, and FIG. 2 is a process diagram illustrating a construction method of the small diameter CFT file of FIG. 1.

CFT pile 102 according to the present invention is made of a small diameter (for example about 200mm). This is because the size of the hole that can be drilled by small equipment (Crawler drill) that can be used in indoor construction is small.

The CFT pile 102 is a pile filled with high-strength concrete in the steel pipe, and welds the steel wire or reinforcement 103 in a circular shape to the outside of the steel pipe to increase friction between the steel pipe and the surrounding mortar. The portion where the steel wire or rebar 103 is welded to the CFT pile 102 is a portion where the CFT pile 102 is embedded in the rock layer 101.

Therefore, the CFT pile 102 is embedded in the rock layer 101 or more by a predetermined depth, and the bottom of the CFT pile 102 is frictionally supported by the rock layer 101, thereby making the foundation very strong.

The iron wire or reinforcement 103 is processed into a circle and welded along the circumferential surface of the CFT pile 102, it is pre-fabricated to reduce the number of processes in the field. Since the depth of the pile 102 embedded in the rock layer 101 is legalized according to the bearing capacity, it is possible to know in advance how much the CFT pile 102 is embedded in the rock layer 101, and thus, the wire or rebar 103. You can set the installation location of.

The CFT pile 102 is manufactured to a constant length and is constructed from the ground surface to the depth of the rock layer 101, so that several steel pipes are combined in a straight line. When the steel pipes are joined, the ends of the steel pipes and the steel pipes are welded, or A screw portion is formed at both ends, and the steel pipe can be joined by a coupling with a tab formed therein.

In order to embed the small-diameter CFT file 102 prepared in advance into the ground 100 and the rock layer 101, a hole for mounting the CFT is drilled with a claw drill. The CFT mounting holes are drilled into the ground 100 and the rock layer 101 at a predetermined depth slightly larger than the diameter of the small diameter CFT pile 102.

Next, the small-diameter CFT pile 102 is placed in the hole for mounting the CFT. At this time, the bottom portion of the CFT pile 102 is poured from the bottom of the inside of the CFT pile 102 using the tremi tube 12 in a state where the bottom surface of the CFT installation hole formed in the rock layer 101 floats by a predetermined height. .

That is, the concrete is poured into and out of the pile at the same time from the bottom of the CFT pile 102 through the bottom of the CFT installation hole formed in the rock layer 101 and the gap between the CFT pile 102.

When the concrete casting is completed to the upper end of the CFT pile 102, before the concrete is hardened, hitting the CFT pile 102 downward with a hammer or the like, so that the lower end of the CFT pile 102 is placed on the bottom of the rock layer 101. Complete pile construction of the building by touching and aligning it vertically.

The small diameter file 102 and the construction method using the CFT according to the second embodiment of the present invention will be described as follows.

3 is a perspective view showing a small-diameter CFT file according to another embodiment of the present invention, Figure 4 is a process chart showing a construction method of the small-diameter CFT file of FIG.

The lower end of the pile is preferably supported by the rock layer 101 so that the CFT pile 102 can effectively withstand the load of the building. In the above-described first embodiment, the steel wire or reinforcement 103 of the CFT pile 102 Mounted on the lower end to improve the principal friction between the steel pipe and the surrounding mortar, in the second embodiment, the cross plate 110 is installed on the lower end of the CFT pile 102 so that the CFT pile 102 is the bottom surface of the rock layer 101 In this case, the tip bearing capacity is improved. Of course, in the first embodiment, the lower end of the CFT pile 102 is supported by the rock layer 101 in principle, but it is difficult to check whether the lower end of the CFT pile 102 touches the rock layer 101. According to the second embodiment, the tip support of the CFT pile 102 is secured.

As described above, in order to place concrete in and out of the CFT pile 102 in the first embodiment, the concrete is filled up to the upper end of the CFT pile 102 with the CFT pile 102 slightly raised from the bottom of the hole for installing the CFT. The bottom of the CFT pile 102 is hit to reach the bottom of the hole for mounting the CFT.

However, it is not easy to check whether the lower end of the CFT pile 102 touches the bottom of the hole for installing the CFT, that is, the bottom of the rock layer 101. Because the depth of the rock layer 101 is, for example, more than 4m deep and the diameter of the CFT pile 102 is small as 200mm, it is impossible to check by ducts, and the CFT to know whether it touches the rock layer 101 by sense. Unloading the file 102 is cumbersome, and it is also inefficient to unload the CFT file 102 several times to verify this each time.

Thus, while maintaining the principal surface friction of the CFT pile 102, the lower end of the CFT pile 102 contacts the rock layer 101, that is, the CFT pile 102 is tip-supported to the rock layer 101. In an embodiment, a cruciform plate 110 is attached to the lower end of the CFT pile 102 so that the cruciform plate 110 contacts the bottom surface of the rock layer 101 of the hole for installing the CFT.

The second embodiment is to construct a pile using a small-diameter CFT, the steel wire or reinforcement (103) on the outer surface of the steel pipe embedded in the rock layer 101 to increase the friction force between the steel pipe and the concrete filled in the rock layer 101 ) Machining and welding in advance are similar to those of the first embodiment.

On the other hand, after drilling the ground 100 and rock layer 101 to drive the small-diameter CFT pile 102, the soil in the ground 100 flows downward when the CFT pile 102 is inserted into the hole. As it descends, it accumulates in the hole of the rock layer 101.

However, if the soil is not removed, there is a problem in that the strength of the concrete that combines the steel pipe and the rock layer 101 is reduced by mixing the soil and concrete during concrete pouring.

Therefore, the CFT pile 102 should be completely removed after the soil accumulated at the bottom of the hole in a state in which a predetermined interval is jumped from the bottom of the hole of the rock layer 101, and then the CFT pile 102 should be constructed.

In the second embodiment, the cross-shaped plate 110 is welded to protrude in the axial direction at the bottom of the inner surface of the CFT pile 102 so that the small-diameter CFT pile 102 is supported at the bottom of the rock layer 101. The studs 111 are attached at regular intervals perpendicular to the cross plate 110. The stud 111 increases the friction between the cross plate 110 and the surrounding mortar, and serves to reinforce the strength of the cross plate 110.

At this time, the protruding length of the cross plate 110 to which the stud 111 is attached depends on the depth of the rock layer 101 on which the small-diameter CFT pile 102 is embedded. For example, the protruding length of the cross-shaped plate 110 is 20 ~ 30cm, the height welded to the inner surface of the lower end of the small diameter CFT pile 102 is about 2 ~ 3cm.

Before the small diameter CFT pile 102 is installed on the ground 100 and the rock layer 101, the cross plate 110 to which the studs 111 are attached is manufactured to be attached to the bottom of the small diameter CFT pile 102 in advance. In the state where the lower end of the cross plate 110 is supported on the bottom of the rock layer 101, concrete may be poured into and out of the small diameter CFT pile 102.

As a result, in the second embodiment, since the CFT pile 102 is supported on the bottom surface of the rock layer 101 by the cross plate 110, the CFT pile 102 and the cross plate (without lifting the CFT pile 102 by a certain height) Concrete may be poured from the bottom into and out of the CFT pile 102 through the openings between the 110.

Thus, the second embodiment ensures that the lower end of the CFT pile 102 is fully supported by the rock layer 101 by the cross plate 110, while lifting and hitting the CFT pile 102 for concrete placement. It has the advantage that it is easier to work by eliminating the hassle.

1 is a perspective view showing a small diameter CFT file according to an embodiment of the present invention,

2 is a process chart showing a construction method of the small-diameter CFT file of FIG.

3 is a perspective view showing a small diameter CFT file according to another embodiment of the present invention,

4 is a process chart showing the construction method of the small-diameter CFT file of FIG.

<Description of the symbols for the main parts of the drawings>

100: ground 101: rock layer

102: small diameter CFT file 103: steel wire or rebar

110: cross plate 111: stud

Claims (3)

In the small-diameter pile 102 using the CFT, It is attached to the ground 100 and the rock layer 101 at a predetermined depth and attached to the outer surface of the CFT pile 102 filled with concrete inside and outside the steel pipe and the CFT pile 102 embedded in the rock layer 101. A friction support reinforcement means, When placing concrete, the friction support reinforcement means can increase the friction between the CFT steel pipe and the surrounding concrete, The cross plate 110 protrudes from the bottom inner diameter surface of the CFT pile 102, and the cross plate 110 protruding from the lower end of the CFT pile 102 is supported by the rock layer 101 before concrete casting. Thus, through the opening between the CFT pile 102 and the cross plate 110, the concrete can be poured from the lower end in and out of the CFT pile, small diameter pile using a CFT. The method according to claim 1, The friction support reinforcement means is a steel wire or reinforcement 103, the steel wire or reinforcement 103 is a small diameter pile using a CFT, characterized in that welded to the outer surface of the CFT pile (102). delete

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