JP2014173229A - Placing joint part structure of concrete structure having wall part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent water leakage from the natural ground side, by enhancing water cut-off performance, in a placing joint part of a concrete structure having a wall part.SOLUTION: When constructing a concrete structure integrated by continuously placing a new concrete structure 10 in an upper part of the concrete structure 10 having the wall part, a projection part 20 of projecting upward is continuously provided in a substantially central part in the longitudinal direction of an upper surface of the existing concrete structure 10. A water cut-off member 30 is arranged on a side surface of the projection part 20. A chamfering part 40 is formed on a natural ground side upper surface of the concrete structure 10, and a caulking material 50 is filled in the chamfering part 40.

Description

  The present invention relates to a joint structure of a concrete structure having a wall portion, for example, a structure that can reliably prevent water leakage at a joint part of a caisson.

  Conventionally, the caisson method is widely used as a method for constructing a soft ground or a concrete structure (for example, a caisson) having walls in water. There are various caisson methods such as the open caisson method and the pneumatic caisson method. While excavating and discharging the earth and sand, the process of sinking the concrete structure into the ground is repeated a predetermined number of times to construct shafts and foundations.

  The technology related to the open caisson method is disclosed in, for example, Patent Literature 1 and the like, and the technology related to the pneumatic caisson method is disclosed in, for example, Patent Literature 2 and the like. In the technique described in Patent Document 1, the inside of the blade edge at the lower end of the caisson removes the adhering matter adhering to the concrete joining surface and closes the lower end of the cylindrical side wall, and the surrounding cylindrical side wall. The purpose is to prevent water leaking from between. In addition, the technique described in Patent Document 2 is intended to ensure the integrity of the joining surface by reducing the strength change in the depth direction with respect to the replacement wall and increasing the water stoppage. It is.

JP 2008-106468 A Japanese Patent Laid-Open No. 9-221864

  By the way, when constructing a concrete structure having a wall as in the conventional caisson method, it is common to cast a concrete structure of a plurality of stages in the vertical direction. There is a need to increase it. In this regard, in the conventional construction method, there is a method of blocking the groundwater infiltration path from the natural mountain side to the inner wall surface side by providing a water stop plate so as to be located at the substantially central portion in the width direction on the upper surface of the concrete structure. It was used. As the water stop plate, for example, water-expandable rubber, vinyl chloride, steel plate or the like is used. If the worker steps on or kicks it by mistake, the water stop plate may be bent or damaged in the worst case.

  In addition, a sealing material is applied to the jointed surface of the concrete, but when the worker steps on it, the applied sealing material may be peeled off.

  When a concrete structure with a general wall thickness (for example, about 1 m) is to be handed over, it is possible to install width stop bars or place form separators from both sides of the wall of the concrete structure. Therefore, it was not necessary for the worker to enter the wall and work. With such a wall-thickness concrete structure, there is no particular problem even with the water stop structure using the water stop plate described above.

  However, when a concrete structure having a thick wall (for example, about 2 m) is handed over, an operator may have to enter the wall in order to assemble a reinforcing bar and a formwork. Even though great care was taken, the waterstop was damaged. If the water stop plate is damaged, water stoppage at the joint surface may not be ensured.

  For such inconveniences, including the techniques described in Patent Document 1 and Patent Document 2 described above, the conventional method for constructing a concrete structure having a wall portion (for example, caisson method) has a large wall thickness. No consideration has been given to ensuring waterproofing at the joints of concrete structures.

  The present invention has been proposed in view of the above-described circumstances, and in a joint portion of a concrete structure having a wall portion, it is possible to enhance water stoppage and reliably prevent water leakage from a natural mountain side. An object is to provide a partial structure.

  The joint structure of a concrete structure having a wall according to the present invention has the following characteristics in order to achieve the above-described object. That is, the joint structure of a concrete structure having a wall portion according to the present invention is used when a new concrete structure is handed over a concrete structure having a wall portion to construct an integrated concrete structure. Further, a convex portion projecting upward is continuously provided at a substantially central portion in the longitudinal direction of the upper surface of the existing concrete structure.

  For example, in the case where the concrete structure is a rectangular hollow body such as a caisson, a convex portion (tenon) that is continuous in the four circumferential directions is provided on the upper surface (joint surface) of the caisson. The lower surface of the concrete that is driven into the upper portion becomes a concave portion with respect to the convex portion, and the convex portion and the concave portion engage with each other on the joint surface.

  Moreover, in the joint part structure of the concrete structure which has a wall part which has the structure mentioned above, it is preferable to arrange | position a water stop member on the side surface of a convex part. The water-stop member is made of, for example, a caulking material or a water-expandable rubber member, and is disposed by applying the caulking material to the side surface of the convex portion or attaching a water-expandable rubber member.

  Moreover, in the joint part structure of the concrete structure which has a wall part which has the structure mentioned above, it is preferable to form a chamfer part in the upper surface by the side of the ground of a concrete structure, and to fill the chamfer part with the caulking material.

  According to the joint portion structure of a concrete structure having a wall portion of the present invention, by providing a convex portion continuous in the longitudinal direction on the upper surface (joint surface) of the concrete structure, without providing a water stop plate. In addition, water can be accurately stopped at the concrete joint. Especially in the case of a concrete structure with a large wall thickness, even if an operator enters the wall part when assembling a reinforcing bar or formwork, the water stop plate does not exist, and the water stop plate may be damaged. There is no, and the water stoppage in the joint part of a concrete structure can be improved.

  In addition, a water-stopping member at the joint portion of the concrete structure is provided by arranging a water-stopping member on the side surface of the convex portion, or by forming a chamfered portion on the upper surface of the ground surface of the concrete structure and filling the caulking material Can be further increased.

Sectional drawing of the joint part structure of the concrete structure which has a wall part which concerns on embodiment of this invention. The perspective view of the joint part structure of the concrete structure which has a wall part which concerns on embodiment of this invention. The enlarged view of the convex part in the joint part structure of the concrete structure which has a wall part which concerns on embodiment of this invention. The enlarged view of the chamfering part in the joint part structure of the concrete structure which has a wall part which concerns on embodiment of this invention.

  Hereinafter, an embodiment of a joint structure of a concrete structure having a wall according to the present invention will be described with reference to the drawings. 1 to 4 illustrate a joint structure of a concrete structure having a wall according to an embodiment of the present invention. FIG. 1 is a sectional view of the joint structure, and FIG. 2 is a diagram of the joint structure. FIG. 3 is an enlarged view of a convex portion, and FIG. 4 is an enlarged view of a chamfered portion.

<Outline of joint structure>
The joint structure of a concrete structure having a wall according to an embodiment of the present invention is a technique used when constructing a concrete structure having a thick wall. In the following embodiment, a caisson method will be described as an example of a technique to which the present invention is applied. The caisson method generally forms a hollow concrete structure such as a rectangle, circle, or ellipse on the ground, and sinks the concrete structure into the ground while excavating and discharging the sediment inside the concrete structure. It is a method of constructing the foundations of shafts and structures by repeating the process a predetermined number of times.

  The present invention is a technique that can be applied to any structure as long as it is a concrete structure having a wall, and the application target is not limited to caisson. In addition, the explanation will be made by taking a rectangular hollow caisson as an example, but the present invention is not limited to the joint portion of the caisson having such a shape, and can be applied to caisson having other shapes. It is a technology that can be done.

  The joint structure of a concrete structure having a wall portion according to an embodiment of the present invention has a reinforcing member and a formwork particularly in a joint surface of a concrete structure having a thick wall portion (for example, about 2 m). Even if an operator enters the wall for assembly, the water-stopping performance is not impaired.

<Convex>
As shown in FIGS. 1 to 3, the joint structure of a concrete structure having a wall portion according to an embodiment of the present invention is used when a new concrete structure 10 is handed over an existing concrete structure 10. In addition, a convex portion 20 that protrudes upward is provided continuously at a substantially central portion in the longitudinal direction of the upper surface (joint surface 60) of the existing concrete structure 10. Although not shown in detail, in order to transfer the concrete structure 10 in the vertical direction, the upper part of the lower concrete structure 10 is arranged inside the mold, and the concrete is driven into the mold, The upper concrete structure 10 is formed. At this time, the convex portion 20 is formed using a floating mold. The width and height of the convex portion 20 can be appropriately changed according to the size of the concrete structure 10 and the like. For example, in the case of the concrete structure 10 having a wall thickness of about 2 m, the convex portion 20 having a width of about 20 cm and a height of about 20 cm is formed.

<Water stop member>
As shown in FIGS. 1 and 3, a water stop member 30 is preferably disposed on the side surface of the convex portion 20. The water stop member 30 may be any member as long as the permeated water from the natural ground side can be blocked at the joint portion. For example, the water stop member 30 formed of a water-expandable rubber, vinyl chloride or the like in a string shape may be attached along the longitudinal direction of the convex portion 20, or a silicone caulking material may be applied.

  Moreover, the water stop member 30 does not necessarily need to be provided on both side surfaces (surface on the natural ground side and surface on the ground side) of the convex portion 20, and particularly when sufficient water can be stopped only on the natural ground side. Alternatively, the water stop member 30 may be disposed only on the natural ground side. When the water stop member 30 is disposed only on one side of the convex portion 20, labor and cost can be reduced.

<Chamfered part>
As shown in FIGS. 1 and 4, the concrete structure 10 is preferably formed with a chamfered portion 40 on the upper surface (joint surface 60) on the natural ground side. And by filling the chamfered portion 40 with the caulking material 50, the groundwater infiltration path from the natural ground side can be blocked. The size and shape of the chamfered portion 40 can be appropriately changed according to the size of the concrete structure 10 and the like. For example, in the case of the concrete structure 10 having a wall portion having a thickness of about 2 m, the chamfered portion 40 having a side of about 1.5 cm and a cross-sectional shape of a U-shape (wedge shape) is formed.

  The caulking material 50 may be any member as long as the permeated water from the natural ground side can be dammed up at the joint portion. For example, the caulking material 50 made of silicone can be used. Further, when it is necessary to further increase the water stoppage, the chamfered portion 40 may be provided not only on the natural mountain side but also on the inner wall surface (vertical shaft) side.

<Comparison with conventional technology>
As described above, in a conventional joint portion of a concrete structure (for example, a caisson joint portion), on the upper surface of the concrete structure, a water stop plate is provided so as to be positioned at a substantially central portion in the width direction, A sealing material was applied to the joint surface to prevent the infiltration of groundwater from the natural ground side to the inner wall surface (for example, the resisting side). Even in the case of such a conventional joint portion, in the case of a concrete structure having a general wall thickness (for example, about 1 m), there is no need for an operator to enter and work on the upper part of the concrete structure. There was almost no problem with water stoppage.

  However, in the case of a concrete structure having a thick wall (for example, about 2 m), an operator may enter the upper surface of the concrete structure in order to assemble a reinforcing bar and a formwork when performing jointing. In addition, there was a risk that the water stop plate was damaged or the sealing material was peeled off.

  Moreover, it is common that latency is generated on the upper surface of a concrete structure formed by driving concrete. However, in the convex part 20 provided in the jointing part of the present invention, no latency is generated on the side surface, and the suspension work can be omitted when the water stop member 30 is disposed. For this reason, not only can the number of work steps be reduced and labor hours can be saved, but also the construction cost can be reduced.

  Moreover, the convex part 20 provided in the jointing part of the present invention has higher strength than a water stop plate made of water-expandable rubber or the like, and is damaged even if an operator steps on or kicks it by mistake. There is little fear. Therefore, it is possible to increase the water stoppage at the joint portion of the concrete structure (for example, caisson), and to significantly improve the quality of the concrete structure as compared with the conventional construction method using the waterstop. .

  Furthermore, the water stop member 30 is disposed on the side surface of the convex portion 20, and the chamfered portion 40 is formed on the upper surface on the ground mountain side to fill the caulking material 50. For this reason, it is possible to effectively prevent the intrusion of groundwater from the natural ground at the joint portion on the natural ground side, and to block the ingress of groundwater by the joint portion bent at the convex portion 20. Furthermore, since the water stop member 30 is disposed on the side surface of the convex portion 20, even if groundwater has entered the convex portion 20, the water stop member 30 can reliably prevent the ingress of groundwater. it can.

DESCRIPTION OF SYMBOLS 10 Concrete structure 20 Convex part 30 Water stop member 40 Chamfering part 50 Caulking material 60 Joint surface

Claims (3)

When constructing an integrated concrete structure by handing over a new concrete structure to the upper part of the concrete structure having a wall portion, in the substantially central portion in the longitudinal direction of the upper surface of the existing concrete structure, Convex parts that protrude upward are provided continuously.
A joint structure for a concrete structure having a wall.   The joint part structure of a concrete structure having a wall part according to claim 1, wherein a water stop member is disposed on a side surface of the convex part.   The joint structure of a concrete structure having a wall portion according to claim 1 or 2, wherein a chamfered portion is formed on the upper surface of the concrete structure on the ground mountain side, and the chamfered portion is filled with a caulking material.

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