JP3749374B2 - Building construction method using existing piles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a building construction method using existing piles.
[0002]
[Prior art]
Cast-in-place piles are widely used in urban areas because they can be constructed with low noise and vibration. When rebuilding such a building, avoiding the core of the existing pile, placing a new pile, or dismantling the existing pile by the method shown in FIG. In the future, it is expected that the demand for rebuilding buildings using such cast-in-place piles 10 will increase more and more.
[0003]
[Problems to be solved by the invention]
However, when rebuilding a building as described above, avoiding the core of the existing pile and placing a new pile, or dismantling the existing pile using the method shown in FIG. However, environmental problems such as noise, vibration and waste associated with dismantling occurred.
[0004]
The present invention has been made in view of such problems, and the purpose of the present invention is to, when rebuilding a building, avoid the core of existing piles, place new piles, or dismantle existing piles. Without building a building.
[0005]
[Means for Solving the Problems]
Means for solving the above problems is that the invention according to claim 1 is that the head of a predetermined existing pile in an existing building is cut to a predetermined length to be edge-cut from the foundation slab, and the edge-cut foundation slab and the existing pile are After installing a jack between the foundation slabs and performing a loading test to confirm the supporting force of the existing piles, the upper frame including the foundation slabs was removed and the ground was excavated to a predetermined depth. Pile head processing of piles is performed, and a mat slab having a predetermined thickness is constructed on these existing piles to construct a new building.
[0006]
According to the invention of claim 1, since existing piles can be used effectively, resources can be used effectively, cost and energy can be reduced by dismantling existing piles, and vibration, noise, waste, etc. associated with dismantling existing piles Can prevent environmental degradation. In addition, by constructing a new building by constructing a mat slab of a predetermined thickness on an existing pile, the positional relationship between the pillar and the pile becomes free.
[0007]
The invention of claim 2 is characterized in that, in claim 1, a new pile is driven in the vicinity of the existing pile.
[0008]
According to the second aspect of the present invention, when the supporting force is insufficient, the necessary supporting force can be obtained by a simple method while keeping the cost low by increasing the number of new piles.
[0009]
The invention of claim 3 is characterized in that, in claim 1, the head of the existing pile is installed with a jack each time a part is cut and removed, and the head is temporarily received by the jack.
[0010]
According to invention of Claim 3, a jack is easily installed by cut | disconnecting a pile head part by cutting one by one, and cutting a pile head part at a time.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a cross-sectional view of the foundation of an existing building, (1) in FIG. 2 is a cross-sectional view in which the heights of the pile heads of existing piles are aligned, and (2) in the same figure is a cross-section in which a mat slab is formed on the pile head. The figure (3) is a sectional view in which a new building is constructed on the mat slab.
[0012]
The building shown in Fig. 1 is an existing building supported by cast-in-place concrete piles (hereinafter referred to as existing piles). The upper frame is dismantled, but the existing piles are used without being dismantled to construct a new building. To do.
[0013]
First, as shown in FIG. 1, the ground 2 is excavated from the foundation slab 1 to about 2 m, and the pile heads 3a of predetermined existing piles (several places) 3 are exposed. Then, a portion of the pile head 3a is cut with a wire saw and cut off with the foundation slab 1, and the jack 4 is installed at the cut edge. The jack 4 scrapes a part of the pile head 3a, that is, about half in plan view and installs one, and scrapes the other half and installs another to temporarily receive the upper casing 5. At this time, the existing pile 3 and the foundation slab 1 are cut off, and the upper part of the jack 4 is in contact with the foundation slab 1.
[0014]
When the jack 4 is thus installed on the pile head 3a, a reaction test is performed on the foundation slab 1 to check the supporting force of the existing pile 3. Since the existing pile 3 is buried in the ground, the compressive strength is almost the same as that of the new pile even if it is a long-term pile after construction, for example, 30 years or more, and the neutralization depth is only 1mm. There are almost no cracks, so it can be confirmed that sufficient support force is maintained. By carrying out such a loading test with an appropriate number of existing piles 3 and assuming that all the existing piles 3 have sufficient supporting force, it is estimated that the entire supporting force is maintained as a whole. .
[0015]
And if it confirms that the existing pile 3 has hold | maintained sufficient support force, as shown to (1) of FIG. 2, the upper frame 5 will be dismantled and removed. At this time, if the supporting force of the predetermined existing pile 3 is insufficient, as shown in the figure, the additional pile 6 is driven in the vicinity of the existing pile 3 to supplement the insufficient supporting force.
[0016]
Next, as shown to (2) of the figure, while excavating the ground 2 to predetermined depth, the pile head process of the existing pile 3 is performed and the height is arrange | equalized. And the mat | matte slab 7 of predetermined thickness is built on these pile heads 3a, and rigidity is strengthened. In addition, when the heights are not aligned, it can be aligned using a wire saw or the like, so that the design can be easily handled.
[0017]
And as shown to (3) of the figure, although the new building 8 is constructed | assembled on the mat slab 7, since it is supported by the existing pile 3 via the mat slab 7, the pillar 9 and the existing pile 3 of The force is transmitted to the existing pile 3 through the mat slab 7 having rigidity and proof strength even if the positional relationship is free, that is, shifted.
[0018]
As described above, the present invention is a much simpler method compared to the case where the existing piles 3 are all removed or the new piles are driven away from the cores of the existing piles 3 as they are. Can be rebuilt.
[0019]
【The invention's effect】
Since existing piles can be used effectively, resources can be used effectively, costs and energy can be reduced by dismantling existing piles, and environmental degradation such as vibration, noise, and waste associated with dismantling existing piles can be prevented. it can.
[0020]
By building a mat slab of a predetermined thickness on an existing pile and building a new building, the positional relationship between the pillar and the pile becomes free.
[0021]
When the supporting force is insufficient, by increasing the number of new piles, the necessary supporting force can be obtained in a simple manner while keeping costs low.
[0022]
When the pile bearing force test is performed, the jack can be easily installed by cutting the pile heads one by one and installing the jacks without cutting the pile head at a time. Moreover, the height of the pile head can be set freely according to the underground depth, so the design is easy to handle.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a state where a jack is installed between a pile head and a foundation slab.
FIGS. 2A and 2B are cross-sectional views in which a newly built pile is added, FIG. 2B is a cross-sectional view in which a mat slab is built on the pile head, and FIG. 3C is a cross-sectional view in which a new building is built on the mat slab. .
FIGS. 3A to 3C are cross-sectional views showing a conventional method of rebuilding a building.
[Explanation of symbols]
1 Foundation slab 2 Ground 3 Existing pile 4 Jack 5 Upper frame 6 Additional pile 7 Mat slab 8 Building 9 Column

Claims (3)

The head of a pre-existing pile in an existing building is cut to a predetermined length and edged with the foundation slab, and a jack is installed between the foundation slab and the existing pile, and the loading test is performed using the foundation slab as a reaction force. After confirming the bearing capacity of the existing piles, the upper frame including the foundation slab is removed and the ground is excavated to a predetermined depth to perform pile head treatment of the existing piles. A building construction method using existing piles, characterized by building a mat slab and building a new building. The building construction method using the existing pile according to claim 1, wherein a new pile is driven in the vicinity of the existing pile. 2. The building construction method using an existing pile according to claim 1, wherein a head is installed every time the head of the existing pile is cut and removed, and the jack is temporarily received by the jack.

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