JPS58204227A - Foundation work of structure - Google Patents

Abstract

PURPOSE:To effectively utilize excavated soil by a method in which usual concrete is placed to the bottom of an excavated pit to form the bottom of foundation to fix steel skeletons, and a concrete mixed with soil generated at the site as aggregate is placed around the steel skeletons. CONSTITUTION:Usual concrete is placed to the bottom reinforced with iron bars of an excavated pit 1 to form the bottom of foundation. Also, steel skeletons 2 are hung down into the excavated pit 1, the fixing part 21 is set on the lower part 31 of the foundation bottom, and concrete is placed until the fixing part 21 is buried to form the upper part 32 of the foundation bottom. In forming the excavated pit 1 on the foundation bottom 3, the aggregate is selected from the excavated soil and packed on the foundation bottom 3 and then cement mortar is poured by a prepacked concrete method to form the intermediate portion 4 of the bottom. Then, the ordinary concrete is placed on the foundation intermediate portion 4 to form the bottom 5 of the foundation. Thus, the foundation of a structure is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a foundation construction method for structures such as iron baths, bridges, and buildings.

Must be. Another issue that is attracting attention is the effective use of soil generated on-site. This is due to the fact that there is less land available for disposal of excavated soil, etc., and transportation costs are rising.

When constructing a foundation for a tower-shaped structure, etc. in a mountainous area,
1) Loading and unloading routes are often not maintained, and 2) Since they are subject to large lifting forces, foundation weight is required to support this. S) Mountainous areas are characterized by the fact that they are often bedrock areas.

Therefore, the method of on-site construction of deep foundation piles is often adopted, but even in this case, a large amount of excavated soil still needs to be carried out.
It will also be necessary to bring in concrete materials, etc.

This invention makes it possible to greatly reduce the amount of excavated soil to be carried in and the amount of concrete materials brought in by sorting the soil generated on site and using it as aggregate. The purpose is to provide a highly reliable foundation construction method for structures that can sufficiently resist

Next, the foundation construction method for a structure according to the present invention will be described in detail in accordance with the construction order based on an example using prepacked concrete shown in FIG.

(1) Excavation Ground is excavated manually or mechanically to form the excavation hole 1. In the figure, OA indicates the topsoil, B indicates the middle layer, and C indicates the supporting layer.

(2) Steel frame members 2 produced at a steel frame assembly factory or the like are assembled on the ground. At the lower end of the steel frame member, there is a fixing section 21 that protrudes in the direction perpendicular to the axis, and a smooth reinforcing bar or the like can be attached to this fixing section 21. Further, a protrusion for enhancing adhesion to concrete, a protrusion for holding an injection pipe, etc. may be provided at any position on the steel frame member 2.

Note that depending on the ground conditions, the condition of the coarse aggregate, etc., rust prevention treatment may be performed by applying hot-dip galvanizing or mortar to the steel frame members.

(3) Formation of the bottom of the foundation Reinforcing bars are placed at the bottom of the excavated hole 1 and ordinary concrete is placed. Furthermore, a concrete slab is poured to such an extent that the support part 21 is fully buried to form the foundation bottom upper part 32, and the formation of the foundation bottom part B is completely completed. As a result, the steel frame member 2 reaches the foundation bottom 3 and is truly integrated, so that compressive force and lifting force can be reliably transmitted to the foundation bottom.

Further, the shape of the base bottom 6 may form a stepped locking portion 35 to effectively counter the lifting force.

(4) Formation of the intermediate part of the foundation A foundation intermediate portion 4 is formed on the foundation bottom portion 3.

The intermediate portion 4 of the foundation is formed by filling aggregate selected from excavated soil and injecting a fixing agent such as mortar using a prepacked concrete method.

In addition, when filling the coarse aggregate 41, reinforcing bars may be placed around the outer periphery of the steel frame member 2 in advance, and an injection pipe 42 for filling with mortar or the like and an inspection pipe for checking the state of mortar filling are also installed. Install. And... out of the excavated soil, diameter 15
Gravels of ~75-y size and larger rock pieces crushed with a crusher etc. are used as coarse aggregate 41, and fine particles with a diameter of about 2.5 mm or less are used as fine aggregate for mortar.
use.

(6) In addition, if the steel frame member 2 is a steel pipe, there are injection holes 22 on the outer periphery.
It is possible to inject mortar etc. through the steel member and around it.

(5) Formation of the foundation head The foundation bottom 5 is formed by pouring ordinary concrete on the foundation middle part 4. In addition, concrete placement for this part is
The injection may be performed either before or after the injection of Sertal into the basal intermediate region 4.

Other Examples: As shown in Fig. 2, when the steel frame member 2 is made of a large diameter steel pipe, it is also possible to fill the steel frame member 2 with coarse aggregate 41 and inject mortar. It is also possible to fill with generated soil.

Since the foundation construction method for a structure according to the present invention has the above configuration, it is possible to obtain the following effects.

(b) Since the excavated soil discharged after forming the excavated hole is used as aggregate, the amount of carrying in construction materials for multiple lids and the carrying out of excavated soil is extremely reduced, which can reduce construction costs.

(b) The foundation head and foundation bottom are made of dense, conventionally used concrete, and pre-packed concrete, etc., which is constructed in the middle of the foundation, is sandwiched from above and below to create a highly reliable foundation structure. In other words, the legs of the structure are securely anchored to the base bottom, and the compressive force applied to the legs is evenly received within the bottom.

(c) Prepacked concrete formed by injecting mortar into the intermediate part of the foundation can resist the lifting force applied to the foundation along with the weight of the foundation due to the friction generated between it and the inner peripheral surface of the excavation hole. becomes. Additionally, since the mortar permeates into the surrounding ground, it is possible to integrate it with the surrounding ground.

(d) Steel members! ! By reaching the bottom of the foundation and integrating it with concrete, the compressive and uplifting forces from the superstructure can be reliably transmitted to the bottom of the foundation. Therefore, even with a large uplifting force, a large tensile stress does not occur in the prepacked concrete in the intermediate part of the foundation, and even with prepacked concrete whose strength is slightly reduced, a highly reliable foundation structure is possible.

Furthermore, the steel frame members will also serve as shear and bending reinforcement for the middle part of the foundation, improving the strength of the entire foundation.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of one embodiment of the construction state of the foundation construction method for a structure according to the present invention, and FIG. 2 is a longitudinal cross-sectional view of another embodiment. DESCRIPTION OF SYMBOLS 1... Excavation hole, 2... Steel frame member, 6... Foundation bottom, 4... Foundation intermediate part, 5... Foundation bottom. 21... Support part, 22... Injection hole, 31... Lower part of foundation bottom, 62... Upper part of base bottom, 41... Coarse aggregate. 42... Injection pipe, M... Topsoil, B... Middle layer. C...No support. (7) Figure 1 Figure 2 Procedural amendment October 15, 1981 1, Indication of the case, 1982 Patent Application No. 87470 2, Name of invention Method of foundation construction for structures 5, Date of amendment order Voluntary action Amendment Showa year, month, day (shipment date) 6, number of inventions increased by the amendment t The description, page 5, line 7, "base bottom" is amended to "base head". 2. In the specification, page 7, line 5, "5...base bottom" is corrected to "5...base head".

Claims (1)

[Scope of Claims] The ground is excavated to form an excavation hole, and a steel frame member to be constructed is fixed at the bottom of the excavation hole. A dense ordinarily used concrete is poured to form the bottom of the foundation, and the foundation is The soil generated on site, such as excavated soil, is sorted onto the bottom and used as aggregate. A foundation construction method for structures in which the foundation head is formed by pouring concrete.