JP4121412B2 - Surface contact type reinforcement structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a technique related to a surface contact type reinforcing structure particularly suitable for reinforcing a new structure foundation.
[0002]
[Prior art]
Conventionally, various reinforcement structures using sheet piles have been developed and provided (see, for example, Patent Documents 1 to 4).
[Patent Document 1]
Japanese Patent Laid-Open No. 11-200395 (see FIG. 1)
[0003]
[Patent Document 2]
Japanese Patent Laid-Open No. 9-158212 (see FIG. 1)
[0004]
[Patent Document 3]
JP 2001-214465 A (see FIG. 1)
[0005]
[Patent Document 4]
JP 2000-238881 A (see FIG. 1)
In any reinforcing structure, the footing and the sheet pile are rigidly coupled.
[0006]
[Problems to be solved by the invention]
However, it is very difficult and expensive to construct the sheet pile and the footing because it has to be done by footing or placing new concrete.
In addition, in the existing reinforcement structure, the footing and the sheet pile are rigidly connected, so the load sharing ratio changes before and after reinforcement, and the load that had been borne by the bottom of the footing is distributed to the sheet pile until then, so that an excessive axial force is applied to the sheet pile. There was a problem that the bending stress was applied and the allowable stress of the sheet pile was reduced by the residual stress. In addition, there is a problem that the resistance at the bottom of the footing is not sufficiently exhibited and the reinforcing effect is not efficient.
The present invention has been made in view of such problems, and an object thereof is to provide a technique capable of solving the above problems.
[0007]
In order to solve the above problems, the present invention has the following configuration.
The gist of the invention described in claim 1 is a method for constructing a surface contact type reinforcing structure that reinforces a structure foundation using a sheet pile, surrounding a footing to be constructed, and contacting a side surface of the footing. A sheet pile placing step for placing the sheet pile, a drilling step for excavating the inside of the sheet pile, a construction step for constructing the footing and a pier, and a portion excavated by the excavation step without combining the sheet pile with the footing. The present invention resides in a method for constructing a surface contact type reinforcing structure comprising a backfilling step.
Summary of the Invention of claim 2, wherein resides in claim 1, wherein, the construction method of surface contact type reinforcement structure, characterized by constructing the footing using the sheet pile which is pouring the mold.
Summary of the Invention of claim 3, wherein, when the footing is existing is the sheet pile, and Da設in contact with the side surface of the footing, according to claim 1, characterized in that it does not bind to said footing In the construction method of the surface contact type reinforcement structure.
SUMMARY OF THE INVENTION according to claim 4 is formed using a method of constructing the surface-contact type reinforcement structure according to any one of claims 1 to 3, is Da設in contact with a side surface of the footing, and the footing Lies in a surface contact type reinforcing structure for reinforcing the foundation of a structure , characterized in that it comprises unconnected sheet piles .
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
As shown in FIGS. 9 and 10, the reinforcing structure according to the present embodiment is provided such that the sheet pile 1 contacts the footing F. There is a gap between the side surface of the footing F and the sheet pile 1. Since the sheet pile 1 does not have a gibber or the like, the sheet pile 1 is cut off from the footing F by stress. The footing concrete 2 is placed from the lower surface to the upper surface of the footing F.
[0009]
Next, a construction method for newly installing the footing F will be described.
As shown in FIGS. 1 and 2, first, the sheet pile 1 is driven and connected so as to be in contact with the side surface of the footing F (shown in FIG. 10) to be constructed. The top of the sheet pile 1 reaches the ground surface.
[0010]
Next, as shown in FIG. 3 and FIG. 4, the inside of the sheet pile 1 is excavated and the beam 3 is formed. Abandoned beam concrete 4 is placed on the bottom of the footing F (shown in FIG. 10).
[0011]
Next, as shown in FIGS. 5 and 6, the lower cut beam 3 is disassembled, and the footing concrete 2 is placed using the sheet pile 1 as a frame. Further, leveled concrete 5 is placed on the bottom surface.
[0012]
Next, as shown in FIGS. 7 and 8, the upper cut beam 3 is disassembled, and the sheet pile 1 positioned above the upper surface of the footing concrete 2 is cut.
[0013]
Next, as shown in FIGS. 9 and 10, a footing F and a pier are constructed. The excavated portion is backfilled, and the cut upper sheet pile 1 is removed.
A reinforcing structure can be constructed by the above steps.
[0014]
Next, the operation of the reinforcing structure will be described.
In the present invention, by surrounding the foundation with the sheet pile 1, (1) the effect of compacting the ground by driving the sheet pile 1, and (2) the effect of suppressing the deformation of the foundation and the ground when a horizontal force is applied to the foundation by the enclosure of the sheet pile 1. (3) In addition to the shear resistance of the ground, the effect of exerting the large shear resistance of the sheet pile 1 structure itself, it is possible to increase the bearing capacity performance of the foundation compared with before placing. In addition, since the footing F and the sheet pile 1 are not coupled, the normal load is received only by the supporting force of the footing F direct base board, and almost no external force is applied to the sheet pile 1, but during an earthquake. Only when an excessive horizontal force or vertical force such as the above acts on the structure, an external force acts on the sheet pile 1 to exert its effect. Therefore, after fully exhibiting the resistance of the footing F, the reinforcement effect by the sheet pile 1 can be expected, and very efficient reinforcement is possible.
[0015]
Although the footing F side surface and the sheet pile 1 are not rigidly connected, they are in contact with each other at a width corresponding to the height of the footing F. As the footing F is horizontally displaced, the load is transmitted to the sheet pile 1 and passes through the sheet pile 1. Since the load is transmitted to the ground in a larger area than the footing F side area, a higher horizontal resistance than before reinforcement can be expected. Further, with the rotational displacement of the footing F, a moment is transmitted to the sheet pile 1 through the footing F contact portion of the sheet pile 1, and a rotational resistance force can be expected due to the bending resistance of the sheet pile 1 and the ground resistance associated therewith. Also, since the relative vertical displacement between the foundation (footing F) and the sheet pile 1 is resisted by sliding resistance, the sheet pile will slide for a long time against the load such as the dead load of the bridge girder. In addition to preventing excessive residual stress from being generated in Fig. 1, it is resistant to short-term loads such as earthquakes, and high damping performance can be expected by energy dissipation due to friction.
In addition, since the footing F and the sheet pile 1 are not joined together, the foundation (footing F) can be displaced (moved), so that an excessive stress can be prevented from being generated in the foundation (footing F) and the pier base. Expected to have the effect of eliminating the need for bar arrangement of connecting members because F and sheet pile 1 need not be combined, and the vibration control effect that reduces the ground motion input to the foundation since the foundation baseboard is surrounded and restrained by sheet pile 1 it can.
[0016]
Next, the effect will be described.
Since the footing F and the sheet pile 1 are not joined, the joining work can be omitted.
Further, there is no need to hook the footing F, and no cross-sectional defect occurs.
Moreover, since the footing F and the sheet pile 1 are not rigidly coupled, they can be vibrated slightly. As a result, when a large earthquake or the like occurs, even if a large acceleration amplitude occurs, it is possible to prevent excessive stress from being generated in the lower part of the pier.
Further, since the sheet pile 1 is used as a formwork, it is not necessary to separately install and remove the formwork and the excavation area can be reduced.
[0017]
Note that the number, position, shape, and the like of the above-described constituent members are not limited to the above-described embodiment, and can be set to a suitable number, position, shape, and the like in practicing the present invention.
Moreover, although the reinforcement structure which concerns on all the said embodiments was applied to the newly installed footing F, it is applicable also to the existing footing. In the existing case, the sheet pile is driven so as to contact the side surface of the footing and is not coupled to the footing.
Moreover, in the said embodiment, although applied to the rectangular footing, it is applicable also to polygons other than a rectangle, and circular footing.
Moreover, in the said embodiment, although the cutting and removal of the sheet pile above a footing upper surface were performed, you may backfill the whole sheet pile without performing them.
In addition, the shape of the horizontal cross section of the sheet pile itself may be a corrugate, a waveform, or the like.
Moreover, it is applicable not only to piers but also to the foundations of abutments and other structures.
In each figure, the same numerals are given to the same component.
[0018]
【The invention's effect】
Since the present invention does not connect the sheet pile and the footing as described above, the construction can be made very easy.
[Brief description of the drawings]
FIG. 1 is a plan view showing a method for constructing a reinforcing structure according to an embodiment of the present invention.
FIG. 2 is a side view of FIG.
FIG. 3 is a plan view showing a method for constructing a reinforcing structure according to an embodiment of the present invention.
4 is a side view of FIG. 3. FIG.
FIG. 5 is a plan view showing a method for constructing a reinforcing structure according to an embodiment of the present invention.
6 is a side view of FIG. 5. FIG.
FIG. 7 is a plan view showing a method for constructing a reinforcing structure according to an embodiment of the present invention.
FIG. 8 is a side view of FIG. 7;
FIG. 9 is a plan view showing a method for constructing a reinforcing structure according to an embodiment of the present invention.
10 is a side view of FIG. 9. FIG.
[Explanation of symbols]
1 Sheet pile 2 Footing concrete 3 Cut beam 4 Discard beam concrete 5 Leveling concrete F Footing

Claims (4)

It is a construction method of a surface contact type reinforcement structure that reinforces the structure foundation using a sheet pile,
Surrounding the footing to be constructed, a sheet pile placing step of placing the sheet pile so as to contact the side surface of the footing ,
An excavation process for excavating the inside of the sheet pile;
A construction process for constructing the footing and the pier;
A method for constructing a surface contact type reinforcing structure , comprising: a step of refilling a portion excavated by the excavation step without coupling the sheet pile with the footing . Of claim 1, the construction method of surface contact type reinforcement structure, characterized by constructing the footing with a pouring has been said sheet pile as formwork. Wherein when the footing is existing is the sheet pile, and Da設in contact with the side surface of the footing, according to claim 1, characterized in that it does not bind to the footings, the construction method of surface contact type reinforcement structure. It is formed using the construction method of the surface contact type reinforcement structure according to claim 1,
Wherein the Da設in contact with the side surfaces of the footing, the characterized in that it comprises a sheet pile which is not coupled to the footing, surface contact type reinforcement structure which reinforces the foundation of the structure.

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