JPH11141126A - Processing method of driving joining part in reversely driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the processing of the driving joining part of the lower end of a preceding concrete wall and the upper end of a rise concrete wall in a reversely driving method. SOLUTION: If a first story floor 6 and a preceding concrete wall 8 are constructed, excavation downward of the floor 6 is performed as the floor 6 is made a supporting, and an underground first floor and a rise concrete wall 12 are constructed. After a reinforcing bar 18 is arranged in a space between an earth retaining wall 4 and a form 20, the rise concrete wall 12 is formed by placing concrete in the space. Thereby a gap S is produced between the lower end of the preceding concrete wall 8 and the upper end of the rise concrete wall 12. The gap S is cleaned to spray concrete of small water containing rate from a nozzle 2202 and filled with it. The surface of concrete is leveled with a ruler and push finishing is performed by a trowel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of treating a spliced portion in a reverse construction method in which a floor is constructed, and then the underground root is cut off using the floor as a support to construct an underground frame.

[0002]

2. Description of the Related Art In a reverse striking method in which a first-floor floor is constructed and then this floor is used as a support to perform underground excavation to construct a basement floor frame, the underground excavation is performed below the floor. The rising concrete wall to be formed casts concrete from above in the formwork, so the lower end of the pre-cast concrete wall (the concrete wall formed around the floor together with the construction of the floor) and the upper end of the rising concrete wall And a gap of about 10 cm to 20 cm is generated between them. On the other hand, after the building is completed, the concrete wall receives the weight of the ground floor and functions as one of the basic building elements supporting the building on the basement floor and the ground floor. Therefore, the joint between the lower end of the precast concrete wall and the upper end of the rising concrete wall needs to be securely connected and integrated with each other. It is extremely important.

[0003] Conventionally, the processing of the spliced portion of the concrete wall is performed as follows. First, a formwork plate is attached between the lower end surface of the pre-cast concrete wall and the upper end surface of the rising concrete wall to close a gap between the lower end of the pre-cast concrete wall and the upper end of the rising concrete wall. An injection port is provided at the lower end of the form plate, and an air vent hole is provided at the upper end. Next, non-shrinkable mortar is injected into the gap from the inlet while discharging air from the air vent hole, and a predetermined filling pressure is applied to fill the gap with the non-shrinkable mortar.

[0004]

However, in the conventional processing method as described above, in order to fill the gap with the non-shrinkable mortar, it is necessary to mount and remove the form plate.
There was a problem that those operations were troublesome. Further, there is a problem that it is difficult to control the pressure when filling the non-shrink mortar. That is, if the filling pressure is too high,
The formwork is deformed. On the other hand, if the filling pressure is low, the non-shrink mortar does not spread sufficiently, and a gap is formed between the non-shrink mortar and the pre-cast concrete wall. Furthermore,
In the conventional processing method, there is also a problem that air is entrapped at the time of filling the non-shrink mortar and air bubbles are generated between the non-shrink mortar and the pre-cast concrete wall. The present invention has been devised in view of the above circumstances, the object of the present invention,
Disclosed is a method of treating a spliced portion in a reverse striking method, which can simplify the processing of a spliced portion between a lower end of a pre-cast concrete wall and an upper end of a rising concrete wall, and can surely integrate both concrete walls. It is in.

[0005]

In order to achieve the above-mentioned object, the present invention relates to a reverse striking method for constructing a floor, constructing an underground skeleton by cutting the underground using the floor as a support, In the gap between the lower end of the pre-cast concrete wall formed around the floor with the construction of the floor and the upper end of the rising concrete wall formed after the underground root cutting below the floor, put concrete with a small moisture content in the gap. It is characterized by being sprayed and filled, and the surface of the sprayed concrete is finished with an iron. Also, the present invention
Particle size is 1-2 as the aggregate of the concrete to be sprayed
It is characterized in that a diameter of about mm is used.

According to the present invention, both concrete walls are efficiently connected by a simple operation of spraying concrete having a low water content into a gap between the lower end of the precast concrete wall and the upper end of the rising concrete wall. Can be integrated. In addition, since the gaps are filled with concrete having a low water content, there is no occurrence of surface dripping, breathing, or concrete settling. Further, concrete having a small water content does not involve air bubbles, which is advantageous in the strength of the concrete wall.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view of a state in which concrete is sprayed into a gap between a lower end of a pre-cast concrete wall and an upper end of a rising concrete wall, and FIG. 2 is an explanatory view of a state in which the gap is filled with concrete and the surface is finished with an iron. Show. Reference numeral 2 denotes underground, and 4 denotes a retaining wall made of H-shaped steel. In the reverse striking method, first, a floor 6 on the first floor and a wall 8 projecting downward from the periphery thereof are constructed inside the retaining wall 4. First floor wall 8, ie, pre-cast concrete wall 8
At the time of constructing, the formwork is arranged via the separator 16 in opposition to the retaining wall 4, and after reinforcing bars 18 are arranged in the space between the retaining wall 4 and the formwork, concrete is poured. It is formed.

When the floor 6 on the first floor and the pre-cast concrete wall 8 are constructed, the floor 6 is used as a support to cut off the lower part of the floor 6, and then the floor and the wall 12 on the first basement are connected. Made.
The wall 12, that is, the rising concrete wall 12 is opposed to the retaining wall 4, and the formwork 20 is disposed via the separator 16. After the reinforcing bar 18 is arranged in the space between the retaining wall 4 and the formwork 20, this space is formed. Is formed by casting concrete from above. Thereby, a gap S of about 10 cm to 20 cm is generated between the lower end of the pre-cast concrete wall 8 and the upper end of the rising concrete wall 12.

In the present embodiment, first, the gap S is cleaned, and then concrete is sprayed from the nozzle 2202 to the gap S using a spraying machine 22 to fill the gap S. When the gap S is filled with concrete, the surface of the concrete is leveled with a ruler, pressed down with a trowel, and after the concrete is hardened, as shown in FIG. The gap S between the upper end of the wall 12 and the wall S is connected and integrated by sprayed concrete. In FIG. 2, reference numeral 24 denotes concrete filled in the gap S and having a finished surface.

In this case, a concrete having a low water content is used as the concrete to be used so as to prevent surface drooling, breathing and sedimentation of the concrete. In addition, the aggregate to be used, when considering the strength of the concrete wall, shrinkage during hardening of the concrete, and the filling property of the gap S,
It is preferable that the material has a size that cannot pass through a sieve of about 1 mm but can pass through a sieve of about 5 mm. In the present embodiment, an aggregate having a particle size of about 1 to 2 mm is used.

According to the present embodiment, the lower end of the pre-cast concrete wall 8 and the rising concrete wall 12
The concrete walls 8 and 12 can be efficiently connected and integrated by a simple operation of spraying concrete into the gap S between the upper end of the concrete wall and the concrete wall. This is advantageous in simplifying the work and reducing the construction cost by eliminating the work of attaching and removing the formwork plate. In addition, since the concrete having a small water content is sprayed and filled into the gap S, no surface drooping, breathing, and sedimentation of the concrete occurs, and therefore, pressure control of the mortar filled in the gap S as in the related art is not required, It is even more advantageous in reducing construction costs. In addition, concrete with a low water content is a semi-fluid intermediate between a fluid and a solid, and this semi-fluid is sprayed without air bubbles, and unlike the conventional method of filling the fluid with a conventional method. Bubbles are generated in the lower part of the cast concrete 8, which is advantageous in the strength of the concrete wall.

[0012]

As is clear from the above description, the present invention
After constructing the floor, in the reverse striking method to construct the underground skeleton by cutting the underground with this floor as a support,
In the gap between the lower end of the pre-cast concrete wall formed around the floor with the construction of the floor and the upper end of the rising concrete wall formed after the underground root cutting below the floor, put concrete with a small moisture content in the gap. The sprayed concrete was filled, and the surface of the sprayed concrete was finished with a trowel. Therefore, both concrete walls can be efficiently connected and integrated by a simple operation of spraying concrete having a low water content into the gap between the lower end of the pre-cast concrete wall and the upper end of the rising concrete wall, Since the gaps are filled with concrete having a low water content, there is no surface drooping, breathing, sedimentation of concrete, and no air bubbles. Therefore, it is possible to simplify the processing of the spliced portion in the reverse driving method, and it is possible to reliably integrate both concrete walls.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a state in which concrete is blown into a gap between a lower end of a pre-cast concrete wall and an upper end of a rising concrete wall.

FIG. 2 is an explanatory view showing a state in which a gap is filled with concrete and a surface is finished with an iron;

[Explanation of symbols]

 2 Underground 4 Mountain retaining wall 6 Floor 8 Precast concrete wall 12 Upstanding concrete wall S Gap

Claims (2)

[Claims] Claims: 1. A reverse-casting method in which a floor is constructed, and then the floor is used as a support to cut an underground and construct an underground frame. The gap between the lower edge of the wall and the upper edge of the rising concrete wall below the floor, which is formed after the underground excavation, is filled with low-moisture content concrete by spraying, and the surface of the sprayed concrete is A method of processing a spliced part in a reverse-casting method, characterized in that the joint is finished with: 2. The method for treating a spliced portion in a reverse-casting method according to claim 1, wherein the aggregate of the sprayed concrete has a particle size of about 1 to 2 mm.