JP2005248428A - Foundation structure for construction - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foundation structure for a construction, which can positively and inexpensively prevent the construction from overturning and lifting due to buoyancy. <P>SOLUTION: According to the construction 1 having its foundation portion 11 constructed in the ground 20 enclosed by an earth retaining walls 12, the foundation portion 11 of the construction 1 is connected to the earth retaining walls 12, and by virtue of the self-weight W of the construction 1 and frictional resistance F between the earth retaining walls 12 and the ground 20, the construction 1 resists lifting force T applied thereto, including drawing force due to overturning of the construction at the time of an earthquake and buoyancy occurring when a groundwater level is high. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a basic structure of a structure that prevents lifting.

  The foundation of a structure is required to have a structure that suppresses overturning due to a load applied to the structure or the foundation and prevents lifting due to buoyancy when the groundwater level is high. Therefore, at the time of design, in order to build a foundation that resists each of these stresses, it is possible to take measures such as expanding the area of the foundation plate, increasing the foundation weight, increasing the number of piles, increasing the pile diameter / pile length, etc. Many. However, such treatment increases the construction cost, takes time for construction, and may limit the construction on a limited site.

  For this reason, various basic structures have been developed and put into practical use for the purpose of increasing the resistance to falling and buoyancy applied to the structure.

  For example, in Patent Document 1, as shown in FIG. 3 (a), floor slab concrete is constructed in order from the top by a reverse driving method while excavating the ground 120 surrounded by the mountain retaining wall 112, and the floor slab is In the structure 101 for constructing a pillar (not shown) to be supported, the foundation structure of the structure 101 for constructing the foundation column 111 in which the pillar and the bottom plate 113 of the structure 101 are integrated and the bottom is widened. Is described. With this foundation structure, a sufficient pulling resistance force F is exerted against the lifting force T acting on the structure 101 without requiring a permanent anchor or additional concrete, and the bottom plate 113 of the structure 101 is completed. It is possible to secure a sufficient support strength for the pillars up to.

In addition, as shown in FIG. 3B, the present applicant attaches a permanent anchor 213 for preventing lifting due to falling and buoyancy to the underground wall or outermost support column 212 constructed integrally with the structure 201. Develops a structure to prevent overturning and buoyancy of the structure 201 that increases the resistance to buoyancy in the event of an earthquake, etc., or when the groundwater level is high, and minimizes the reinforcement associated with the permanent anchor 213 installation However, it has been put to practical use (see Patent Document 2).
JP-A-8-3986 ([0008]-[0017], FIG. 1) Japanese Unexamined Patent Publication No. 5-44221 ([0005]-[0009], FIG. 1)

However, the former method of constructing the foundation struts 111 requires labor and cost for drilling and concrete placement for constructing the plurality of foundation struts 111, and hinders short-term construction and reduction of construction costs. There's a problem.
On the other hand, in the latter structure for preventing overturning and lifting by the permanent anchor 213, the permanent anchor 213 is installed on the underground wall or the column 212 which is a part of the foundation of the structure 201. There is a concern that a reinforcement work may be required, and in these base portions 211, it is necessary to arrange the reinforcing bars and permanent anchors 213 required by the base portion 211 of the structure 201 in a limited cross section, There was a problem that the work might be time-consuming.

  The present invention aims to solve the above-described problems, and provides a foundation structure of a structure and a method for constructing the structure that reliably and inexpensively prevent the structure from overturning and lifting due to buoyancy. The task is to do.

  In order to solve the above problems, the basic structure of the structure according to the present invention is a structure in which a foundation is constructed on the ground surrounded by a mountain retaining wall, and the foundation of the structure and the mountain retaining wall are The structure is characterized in that the structure is prevented from being lifted by its own weight and the frictional resistance between the mountain retaining wall and the ground.

  With the basic structure of such a structure, the lift force generated by the fall of the structure or the buoyancy of groundwater is reduced by the frictional resistance force between the mountain wall and the ground, so that the structure is prevented from being deformed. Can do.

  According to the present invention, by using a mountain retaining wall that has been provided as a temporary structure in the past as a foundation part integrated with the structure, a pull-out generated by a fall during an earthquake or the like without adding or newly installing a foundation member It is possible to build a basic structure that prevents lifting due to buoyancy in the ground with high strength and groundwater level at a low cost and in a short period of time.

  Preferred embodiments of the present invention will be described with reference to the drawings. In the description, the same reference numerals are used for the same elements, and duplicate descriptions are omitted.

  FIG. 1 shows a cross-sectional view of a structure 1 having a foundation structure 10 according to the present invention. The structure 1 is subjected to a pulling-out force caused by a fall during an earthquake or the like and a lifting force T due to the buoyancy of groundwater. ing. FIG. 2 is a schematic view showing the relationship of the frictional resistance force F between the mountain retaining wall 12 and the ground 20.

  As shown in FIG. 1, the structure 1 according to the present embodiment is a building constructed on the ground having a high groundwater level, and the foundation structure 10 of the structure 1 includes a foundation portion 11 and a foundation of the structure 1. It is comprised from the mountain retaining wall 12 joined to the part 11. FIG.

Here, the mountain retaining wall 12 is an underground continuous mountain retaining wall installed for constructing the foundation part 11 and is trenched so that the excavation surface does not collapse using a stabilizing liquid such as bentonite water. After excavation, the bentonite water is mixed with cement or other solidified material, and H-shaped steel (hereinafter sometimes referred to as “stress material”) is cast as a core material at predetermined intervals. It is.
The foundation 11 is constructed after excavating the ground surrounded by the mountain wall 12. In addition, the foundation part 11 and the mountain retaining wall 12 are joined by fastening or welding the steel member of the foundation part 11 and the core material of the mountain retaining wall 12 with a bolt or the like.

  The installation position, depth, strength, and cross-sectional shape of the mountain retaining wall 12 and the stress material are appropriately determined so that the lifting force T generated in the structure 1 can be resisted. And the foundation structure 10 of this Embodiment resists the lifting force T with the frictional resistance force F of the mountain retaining wall 12 and the ground 20, and the dead weight W of a structure, and shows to Formula 1. As described above, the sum of the frictional resistance force F and the own weight W is configured to be larger than the lifting force T.

  T <W + F (Formula 1)

  As shown in FIG. 2, an upward lifting force T is applied to the structure 1 between the mountain retaining wall 12 and the ground 20, thereby causing a downward frictional resistance force (hereinafter referred to as “solidified ground friction force”). F1 occurs. At the same time, in the interior of the retaining wall 12, a downward frictional resistance force between the stress member 13 and the retaining wall solidified body 14 (hereinafter sometimes referred to as "stressed material solidified body frictional force") F2 (See FIG. 2).

  Then, the lifting force T applied to the structure 1 is borne by the smaller frictional resistance force F of these solid body ground friction force F1 and stress material solid body friction force F2 (see Formula 2). .

  F = MIN (F1, F2) (Formula 2)

  According to the foundation structure of the structure described above, by using the mountain retaining wall 12 that has been conventionally used as a temporary structure as a part of the foundation structure 10 of the structure 1, an additional permanent anchor or foundation concrete is provided. It is possible to resist by the frictional resistance force F of the mountain retaining wall 12 without performing special processing to resist the lifting force T. Therefore, it is possible to reduce labor and material costs required for the above-mentioned special processing, so that the construction period can be shortened and the construction cost can be reduced.

Heretofore, an example of a preferred embodiment has been described for the present invention. However, the present invention is not limited to the above-described embodiment, and the design of each of the above-described components can be appropriately changed without departing from the spirit of the present invention.
For example, in the above-mentioned embodiment, the underground continuous mountain retaining wall having the core material is used as the mountain retaining wall. However, the configuration of the mountain retaining wall is not limited, and the reinforced concrete structure or the steel sheet pile method is used. However, it may be determined appropriately in consideration of the ground conditions, the workability of the foundation part, the bondability with the foundation part, the economy, the workability, and the like.
In the above embodiment, the foundation and the retaining wall are joined by joining the steel member of the foundation and the core of the retaining wall. However, the present invention is not limited to this. Instead, for example, in the case of a reinforced concrete structure, a structure may be adopted in which one main reinforcing bar is extended so as to enter the other cross section to be integrated.

It is sectional drawing which shows the structure which has a basic structure by this invention. It is the schematic which showed the relationship of the frictional resistance force of a mountain wall and the ground. It is sectional drawing which shows the conventional lifting prevention structure, (a) is a foundation support type foundation structure, (b) is an anchor type foundation structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Structure 10 Foundation structure 11 Foundation part 12 Yamadome wall 13 Stress material 20 Ground F Friction resistance T Lift force W Own weight

Claims (1)

In the structure where the foundation is built on the ground surrounded by the Yamato wall,
The foundation of the structure and the mountain retaining wall are joined,
A foundation structure of a structure, wherein the structure is prevented from rising by its own weight and a frictional resistance force between the mountain retaining wall and the ground.

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