JPH0748846A - Construction method for synthetic underground wall utilizing soil cement column line wall - Google Patents

Abstract

PURPOSE:To utilize the core material of a soil cement column line wall as part of the permanent underground wall of a synthetic underground skeleton. CONSTITUTION:A short threaded bolt 3 is fitted by welding on the inside face of the core material 2 of an underground wall in advance, and a protective cap 4 is fitted to the bolt 3. After the construction of a soil cement column line wall 1 is completed, soil cement is removed to the inside face of the core material 2. The protective cap 4 of the threaded bolt 3 is removed, and a threaded connector 5 is screwed to the threaded bolt 3 via a joint coupler 6. Horizontal/vertical bars 7 are arranged in an underground wall portion, a formwork 8 is installed at the inner position of the underground wall, and concrete 9 is placed. Since the short threaded bolt 3 is fitted to the core material 2 in advance, the execution quality of the weld portion is improved, a large- diameter connector can be employed via the joint coupler 6, and this contributes to the construction of the soil cement column line synthetic underground wall having high execution property and reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a core material (usually H-shaped steel) of a soil cement column wall adopted as one of the mountain retaining wall construction methods as a part of a main underground wall of a synthetic underground wall. To do
A method of constructing a synthetic underground wall.

[0002]

2. Description of the Related Art Conventionally, the soil cement column wall construction method has been widely adopted as a mountain retaining wall construction method for constructing an underground wall. In this construction method, the core material of the mountain retaining wall is generally used only as a temporary construction, and it is uneconomical because it remains buried during the main construction. Therefore, a so-called soil cement column composite underground wall construction method has been studied and adopted, in which a core material and an underground wall are integrated (synthesized) by a connector such as a stud connector to form a permanent underground wall (for example, Japanese Patent Publication 48-116
07, refer to the construction method described in JP-A-58-29922, etc.).

To describe a general example in detail, a core material 2 is built and installed in a soil pillar to construct a soil cement pillar row wall 1, and at the time of root cutting of the ground after its completion, up to the inner surface of the core material 2. Remove soil cement (see Figures 1A, B). After that, the inner surface of the core 2 which is to be joined to the connector is ground by a grinder or the like to remove rust, and then the stud connector 10 having a predetermined length shown in FIG. 3 is welded to the joining position in a horizontal position (FIG. 1C). reference). And the horizontal and vertical stripes 7 on the basement wall
Are reinforced and integrated with the core material 2, the formwork 8 is installed at the inner surface position of the underground wall, and the concrete 9 is placed (Figs. 1D and 1E).
This is a construction method for constructing a soil cement composite underground wall (Fig. 3).

[0004]

The above-mentioned conventional method for constructing a synthetic underground wall has the following problems. Since the work posture when welding the stud connector 10 to the core material 2 is horizontal (see FIG. 3), the workability is poor as compared with the case of working in the downward posture. In particular, when the depth of the underground wall becomes large and a stud connector having a large diameter is used due to its design, the molten metal flows down and welding work is very difficult, and therefore the quality of the welded portion is also deteriorated. By the way,
When using a stud connector, the thickness (shaft diameter) is φ according to the “Guidelines for Composite Structure Design” established by the Japan Institute of Architecture.
It is stipulated that welding up to 16 is permitted in a horizontal posture, and welding of larger diameter studs beyond that is performed downward. Therefore, the method of using a large-diameter connector and quality control are issues to be solved. In order to solve the above-mentioned problem, a method of pre-welding a connector, in particular, the large-diameter and long connector 10 to the core material 2 in a factory is as shown in FIG. The hole wall surface of the pillar and the connector 10 may come into contact with each other, which may cause a situation in which the construction cannot be performed. According to the "Various Composite Structure Design Guidelines", L≥4.0d, where L is the length of the stud connector and d is the shaft diameter. Therefore, a large-diameter stud connector having a large shaft diameter (d) has a proportionally long overall length (L), and contact with the hole wall surface of the soil column cannot be avoided. on the other hand,
If the diameter of the soil cement column 1 is increased in order to avoid the contact, the construction cost will be reduced. In addition, when the connector 10 is welded in advance, the root cutting operation for removing soil cement on the inner surface of the core material 2 (see FIG.
(See B), there is a risk that the connector 10 may be damaged by an excavating machine or the like. Therefore, if the work is carefully performed, the work efficiency may be reduced. In addition, the stud connector 1 can be used on-site as in the conventional case.
When welding 0 ..., the work of polishing the inner surface (surface) of the core material 2 with a grinder or the like before the welding is very troublesome and troublesome. On-site connector welding work requires large-scale wiring to the power generation equipment and work place. Further, there is a problem in that the welding work of the connector is performed in duplicate with the excavation work, which is dangerous.

Therefore, an object of the present invention is to solve the above-mentioned problems all at once, and even when a connector having a large diameter is used, the quality of the cement cement column can be ensured and a simple and reliable construction can be performed. It is to provide a method for constructing a synthetic basement wall using a wall.

[0006]

As a means for solving the above-mentioned problems of the prior art, a method of constructing a synthetic underground wall using a soil cement column wall according to the present invention is the construction of a soil cement column wall 1. At this time, a short threaded bolt 3 is attached to the inner surface of the core material 2 by welding in advance, a protective cap 4 is attached to the threaded bolt 3, and the core material 2 is installed and installed. After the construction of the wall 1 is completed, the soil cement is removed to the inner surface of the core material 2 along with the root cutting of the ground, the protective cap 4 of the threaded bolt 3 is removed, and the total length is required via the joint coupler 6. A threaded connector 5 having a length corresponding to the design stud length is screwed to the threaded bolt 3, vertical and horizontal bars 7 are arranged on the underground wall portion, and a form 8 is formed at the inner surface position of the underground wall.
Is installed and concrete 9 is placed.

[0007]

[Operation] Since the short threaded bolt 3 is preliminarily attached to the core material 2 at a factory in advance and the protective cap 4 is attached to the threaded bolt 3 (FIGS. 2A and 1A), when the core material 2 is to be built. Moreover, the threaded bolt 3 does not contact the hole wall of the soil cement column (see FIG. 4). Further, even when the soil cement is removed to the inner surface of the core material 2, the threaded bolt 3 is not damaged and the work can be smoothly performed (FIG. 1).
B). Then, the protective cap 4 is removed, and the threaded connector 5 is threadedly joined to the threaded bolt 3 through the joint coupler 6 to obtain a large-diameter threaded connector 5 having a predetermined stud length and high strength. It is easily installed (Fig. 2B) and improves the workability of synthetic underground walls.

[0008]

EXAMPLE An example of the present invention shown in the drawings will be described below.
1A to 1E sequentially show process diagrams of a method for constructing a synthetic underground wall according to the present invention. As is clear from FIGS. 1A and B, and further in FIG. 2A, in the H-shaped steel 2 that is the core material of the soil cement column wall 1, at a substantially intermediate position of the flange 2a on the inner surface (on the extension line of the web), The short threaded bolt 3 is attached by welding in advance as factory processing (or processing on-site, etc.). The threaded bolt 3 has a total length as short as a necessary minimum (about 50 mm), an outer diameter of φ22 or more and a thread ridge formed on the outer circumference, and is joined with a threaded connector 5 described later to form an overall thread. It constitutes a base forming a long stud connector. The short threaded bolt 3 is provided with a protective cap 4 which covers almost the entire surface and is large enough to protect it from dirt, rust and the like caused by earth and sand. The core material 2 having such a configuration is built in the center position of the drilled soil cement column to construct the soil cement column row wall 1 (FIG. 1A).

After the construction of the soil cement column wall 1 is completed, ground excavation work is carried out by an unillustrated excavating machine or soil cement removing machine. As shown in FIG. 2. Remove soil cement up to the inner flange surface of 2. At this time, the protective cap 4 attached to the threaded bolt 3 protects the thread of the threaded bolt 3 and effectively prevents damage by an excavating machine or the like, and the soil cement of the joint portion of the threaded connector 5 Surely remove stains caused by. Then, as shown in an enlarged view in FIG. 2B, the protective cap 4 is removed, and the threaded connector 5 is threadedly joined to the threaded bolt 3 via the joint coupler 6 (FIG. 1C). More specifically, the threaded connector 5 has the same outer diameter as the threaded bolt 3 and a total length of about 100 mm. The threaded connector 5 has a screw thread at its head and a bearing plate 5a at its head. . Considering concrete bearing pressure resistance of the threaded connector 5, its length is sufficiently secured. The joint coupler 6 is a cylindrical body (sleeve nut) having a thread groove on the inner peripheral surface and having an inner diameter substantially the same as the outer diameter of the threaded bolt 3 (threaded connector 5). After screwing one side of the joint coupler 6 into the threaded portion of the threaded bolt 3, the threaded portion of the threaded connector 5 is screwed into the other side. Thus, the threaded bolt 3 and the threaded connector 5 are easily joined via the joint coupler 6, and the total joining length corresponds to the design stud length, and a large-diameter stud connector of φ22 or more with high strength is completed easily and quickly. To be done.

After that, the vertical and horizontal reinforcements 7 for the wall of the underground wall are laid out as double reinforcements inside and outside (Fig. 1D), and after all the reinforcement work is completed, the frame 8 is placed at the inner surface position of the underground wall. Assembly,
Concrete 9 is cast to construct a synthetic underground wall integrated with the soil cement column wall (Fig. 1E). Therefore, according to this embodiment, a large-diameter connector of φ22 or more can be installed easily, quickly and with high quality, and a high strength and highly reliable synthetic underground wall is constructed by using the soil cement column wall. (See Figure 3).

[0011]

The effect of the present invention The construction method of a synthetic underground wall using a soil cement column wall according to the present invention has the following effects. Since the short threaded bolt 3 is welded to the core material 2 in advance by factory processing, the construction quality and accuracy of the welded portion are improved. Moreover, since the threaded connector 5 is easily connected using the joint coupler 6, a large diameter stud connector can be adopted, which is excellent in workability and reliability, and has high accuracy.
Contributes to the construction of highly rigid soil cement column composite basement walls. Since the core material 2 to which the short threaded bolt 3 is attached is built in the soil column, the connector does not contact the hole wall of the soil column 1. When the soil cement on the inner wall surface of the core material 2 is removed, there is no possibility that the short threaded bolt 3 will be damaged by an excavator or the like, resulting in excellent workability. Since the threaded bolts 3 are attached in advance at the factory, it is not necessary to grind the surface of the core material 2 with a grinder or the like after cutting the roots. In addition, no on-site welding work or welding quality control is required. Since the work at the site is extremely simplified, the equipment and tools required at the site are extremely simple, and the construction cost is reduced. In addition, it does not require qualified personnel for stud welding, which contributes to saving labor costs and shortening the construction period. Duplicate work of excavation work and stud welding is reduced, and work safety is secured.

[Brief description of drawings]

1A to 1E are process diagrams showing the construction method of the present invention in the order of essential steps.

FIG. 2A and FIG. 2B are enlarged views showing a joining procedure of a threaded connector.

FIG. 3 is a cross-sectional view showing a conventional example.

FIG. 4 is an enlarged view showing a conventional core member and a stud connector.

[Explanation of symbols]

 1 Soil cement column wall 2 Core material (H-shaped steel) 3 Threaded bolt 4 Protective cap 5 Threaded connector 6 Joint coupler 7 Vertical and horizontal streaks 8 Formwork 9 Concrete

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroyuki Nishioka 2-5-14 Minamisuna, Koto-ku, Tokyo Incorporated Takenaka Corporation Technical Research Institute

Claims (1)

[Claims] 1. When constructing a soil cement column wall, a short threaded bolt is previously attached to the inner surface of the core material by welding, a protective cap is attached to the threaded bolt, and then the core material is installed and installed. After completing the construction of the soil cement column wall, remove the soil cement up to the inner surface of the core material along with root cutting of the ground, remove the protective cap of the threaded bolt, and through the joint coupler, Is to be threaded on the threaded connector with the required design stud length to the threaded bolt, and to arrange vertical and horizontal bars on the underground wall, install a formwork on the inner surface of the underground wall, and cast concrete. To set up,
Construction method of composite underground wall using soil cement column wall.