JP7204228B2 - Underground beam construction method - Google Patents

Description

The present invention relates to an underground beam construction method.

Conventional underground beam construction methods include, for example, as disclosed in Patent Document 1, after performing earthwork for excavating the ground, reinforcement work for placing reinforcing bars of the underground beam, It is common to perform formwork construction, etc. to assemble the formwork at Earthwork, reinforcement work, and formwork are carried out according to the order of construction by specialists in earthwork, reinforcement work, and formwork. Vehicles such as trucks are used to carry out the excavated soil.

JP-A-10-195886

However, in the foundation work for arranging underground beams over a wide area, excavation of the ground tends to restrict the passage of vehicles to the construction site, making it difficult to bring in materials. As a result, earthwork, reinforcement work, and form work cannot be carried out efficiently, and a large crane vehicle is required to bring in and move materials, which may increase the construction period and construction costs. was there. In addition, large crane trucks not only have the risk of overturning, but also pose problems such as reduced work efficiency due to slow movement, restrictions on installation space, road traffic restrictions, etc., and require advanced driving skills. Therefore, there is a growing need for construction without the use of large crane vehicles.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an underground beam construction method that enables safe construction while shortening the construction period and reducing construction costs.

The above-mentioned object of the present invention includes a storage trench forming step of excavating the ground to form a storage trench, and an underground beam construction step of placing an underground beam reinforcing bar in the storage trench to construct an underground beam. In the method for constructing a center sill, the accommodation groove forming step includes a narrow width portion forming step of forming a narrow width portion having a narrower opening width than other portions in a part of the accommodation groove in a longitudinal direction; a passage forming step of placing a floor plate above the narrow portion to form a temporary passage through which construction vehicles can pass, wherein the narrow portion forming step includes forming a narrow portion in a space formed by excavating the ground. A step of placing a forming formwork, filling improved soil obtained by mixing earth and sand with a solidifying material around the narrow part forming formwork and solidifying it, and then removing the narrow part forming formwork. In addition, in the accommodation groove forming step, after arranging the bottom plate so as to be supported by the portion of the narrow portion where the improved soil is solidified, the other portion communicating with the narrow portion is excavated and the This is achieved by the method of constructing underground beams that form a containment ditch .

According to the underground beam construction method of the present invention, safe construction can be performed while shortening the construction period and reducing the construction cost.

It is a top view for demonstrating 1 process of the construction method of the underground beam which concerns on one Embodiment of this invention. FIG. 4 is a plan view for explaining another step of the underground beam construction method according to the embodiment of the present invention; FIG. 4 is a plan view for explaining still another step of the underground beam construction method according to the embodiment of the present invention; 2 is a process cross-sectional view corresponding to the process of FIG. 1; FIG. FIG. 3 is a process cross-sectional view of a process performed subsequent to the process of FIG. 2 ; It is a cross-sectional view of the constructed underground beam.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. 1 and 2 are plan views for explaining each step of a method for constructing an underground beam according to an embodiment of the present invention. The underground beam construction method of the present embodiment includes a storage groove forming step of excavating the ground at a location where the underground beam that will be the foundation of the building is to be constructed and forming a storage groove.

As shown in FIG. 1, in this accommodation groove forming step, a narrow portion 12 having an opening width smaller than that of the other portion of the accommodation groove 10 is previously formed in a part of the intended formation location of the accommodation groove 10 indicated by the dashed line. Later, as shown by solid lines in FIG. 2, by forming other portions of the housing groove 10, the housing groove 10 extending linearly is formed so as to include a narrow portion 12 in a part of the longitudinal direction thereof. be. The narrow portion 12 is a space portion having a minimum width necessary for constructing an underground beam, and serves as a side formwork when placing concrete. As shown in FIG. 2, by arranging a floor plate 14 such as a steel plate in the narrow portion 12, a temporary passageway through which construction vehicles such as unic vehicles, trucks, and heavy machinery can pass can be formed. By providing such a passage forming process, it is possible to quickly and easily perform an underground beam construction process for constructing an underground beam by arranging the underground beam reinforcing bars 20 in the accommodation groove 10 as shown in FIG. The length of the narrow portion 12 in the longitudinal direction (horizontal direction in FIGS. 1 to 3) is sufficient as long as it can secure a passage for construction vehicles, and is, for example, about 3.0 m.

The locations where the narrow width portions 12 are formed in the accommodation groove 10 are not necessarily limited. is preferably formed. For example, in FIG. 2, the narrow portion 12 and the bottom plate 14 are arranged at a plurality of locations so that a construction vehicle entering in the direction of arrow A from a road (not shown) can access the entire storage groove 10 . As a result, it is possible to easily carry in materials and carry out earth and sand in the vicinity of each construction site. Reinforcement work, formwork work, etc. can be carried out simultaneously and continuously at various locations, shortening the construction period and reducing construction costs.

FIG. 4 is a process cross-sectional view for explaining the narrow width portion forming process for forming the narrow width portion 12 shown in FIG. In the narrow width portion forming step, as shown in FIG. 4(a), the ground 30 is excavated and removed to form a groove-shaped space 31, and then, as shown in FIG. 4(b), excavation is performed. A small amount of improved soil 35 is prepared by mixing earth and sand such as soil and a solidifying material such as cement with water, and is supplied to the space 31. It is arranged at a predetermined position in the space 31 so as to sink. Although the size of the space 31 is not particularly limited, in this embodiment, it is the same size as the other parts of the accommodation groove 10, and the opening width of the upper part of the space 31 (the length in the left-right direction in FIG. 4) is about 2.4 m, the width of the base is about 1.0 m, and the depth is about 1.2 m.

When the improved soil 35 solidifies to some extent and the narrow portion forming formwork 34 is fixed, as shown in FIG. Add 35 to fill. After the improved soil 35 is solidified, the narrow portion 12 is formed by removing the narrow portion forming formwork 34 as shown in FIG. 4(d). The width of the opening of the narrow portion 12 (length in the left-right direction in FIG. 4) is large enough to accommodate an underground beam, and is, for example, about 250 to 500 mm. The opening width of the narrow portion 12 is preferably the minimum necessary width for constructing an underground beam, and is set smaller than the opening width (for example, about 2.4 m) of the other portions of the accommodation groove 10. .

By performing the narrow portion forming step as described above, the floor plate 14 arranged above the narrow portion 12 in the subsequent passage forming step shown in FIG. Since it can be supported, a construction vehicle can safely pass through the bottom plate 14, and the carrying in of materials, the carrying out of excavated soil, etc. can be carried out safely and efficiently without carrying out work with a large crane truck. It should be noted that the placement and removal of the sole plate 14 can also be carried out at any time by using an excavator, a unique car, or the like. The narrow portion forming process is not necessarily limited to that of the present embodiment. For example, gravel is spread in the space portion 31, dump concrete is placed, and the narrow portion forming formwork 34 is placed thereon. After that, a method of filling improved soil 35 around the narrow portion forming formwork 34 may be used.

As shown in FIG. 2, the accommodation groove 10 of the present embodiment is formed to include the narrow width portion 12 by excavating so as to communicate with both sides of the narrow width portion 12 in the longitudinal direction. FIG. 5 is a process cross-sectional view for explaining an underground beam construction process that follows the process of forming the accommodation groove 10 shown in FIG.

In the underground beam construction process, as shown in FIG. 5(a), gravel 32 is spread on the bottom surface of the housing portion 10 formed in the ground 30, and rolling compaction is performed. , the underground beam reinforcing bars 20 such as main reinforcing bars and ties are carried into the storage section 10 and assembled. Next, as shown in FIG. 5(b), the formwork materials are brought into the accommodation section 10 and assembled, and the underground beam formwork 36 is constructed so that the underground beam reinforcing bars 20 are arranged inside. . At this time, the floor plate 14 shown in FIG. 4(e) is removed, and the underground beam reinforcing bars 20 are arranged also in the narrow width portion 12, and are connected to the underground beam reinforcing bars 20 arranged on both sides of the narrow width portion 12. .

Next, as shown in FIG. 5(c), the ready-mixed concrete 37 is carried into the underground beam formwork 36 and the concrete is poured, whereby the underground beam reinforcing bars 20 and the concrete 37 are integrated. Then, an underground beam 40 is constructed. The inside of the underground beam formwork 36 communicates with the narrow width portion 12, and as shown in FIG. is constructed. Then, as shown in FIG. 5(d), after dismantling the underground beam formwork 36 and carrying out the formwork material, as shown in FIG. Construction of the underground beam 40 is completed by rolling.

In the construction method of the underground beam of the present embodiment, in the accommodation groove forming step, only the portion corresponding to the narrow width portion 12 of the ground is excavated to form the narrow width portion 12, and then the narrow portion 12 is communicated with. Although the storage groove 10 is formed by excavating the portion of , the space portion 31 may be formed by excavating a portion longer than the narrow portion 12 in advance as long as it does not hinder the construction. In this case, part of the space 31 can be closed with a mold or the like to form the narrow portion 12 , and the remainder of the space 31 can be used as the accommodation groove 10 .

10 Accommodating groove 12 Narrow part 14 Floor plate 20 Underground beam reinforcing bar 30 Ground 40 Underground beam 31 Space part 1 Formwork for forming narrow part

Claims (1)

an accommodation groove forming step of excavating the ground to form an accommodation groove;
An underground beam construction method comprising an underground beam construction step of placing underground beam reinforcing bars in the accommodation groove to construct the underground beam,
The accommodation groove forming step includes a narrow width portion forming step of forming a narrow width portion having a narrower opening width than other portions in a part of the accommodation groove in the longitudinal direction, and a bottom plate disposed above the narrow width portion. and a passage forming step of forming a temporary passage through which construction vehicles can pass,
In the narrow portion forming step, a narrow portion forming form is arranged in a space formed by excavating the ground, and improved soil obtained by mixing soil and sand with a solidifying material is applied around the narrow portion forming form. After filling and solidifying, removing the narrow part forming formwork,
In the accommodation groove forming step, after arranging the floor plate so as to be supported by the portion of the narrow portion where the improved soil is solidified, the other portion communicating with the narrow portion is excavated to form the accommodation groove. Construction method of underground beams that form

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