JPH07259103A - Improving method for soft ground - Google Patents

Abstract

PURPOSE:To prevent a building on the soft ground from sinking unevenly, and to especially prevent sinking from going on, which has been occurring at a densely built-up area. CONSTITUTION:A long sleeve-shaped woven fabric bag 4 made so as to be turned to a pile formed in special shape by the expansion thereof is inserted into a hole drilled under a foundation 2 for a building 1, together with an injection pipe 5, and an infilling material 6 to be allowed to solidify as time goes by is forced into the woven fabric bag. The top part of the bag formed in the special shape by the injection of the infilling material 6 is integrally fastened to the foundation.

Description

[Detailed Description of the Invention] In an area where clay layers having a depth of several to several tens of US are mainly used, when building or installing a building or heavy object, the foundation of them is the composition of the ground, Designed and constructed in consideration of all soil properties such as clay type. That is, the ground on which the foundation acts must surely retain its proof stress. On soft ground, however, differential settlement often occurs in relation to groundwater and neighboring properties. The present invention has been devised to prevent such a phenomenon, and it will be explained with reference to the drawings. Fig. 1 is a schematic diagram of the construction method of the present invention, which is drilled directly under the foundation (2) of an existing building (1). A long tubular woven fabric bag (4) specially woven for use in the method of the present invention is inserted into the hole (3) together with the injection pipe (5). FIG. 2 shows an example of the woven bag (4) which is inflated by injecting the filling (6), and FIG. 3 shows the filling (6) of the woven bag (4) which solidifies with the passage of time. It is a schematic diagram showing a process of sequentially pulling out the injection pipe (5) while injecting and filling from the tip (lowest) through the injection pipe (5). Fig. 4 is a completed construction drawing of the proposed method. The top of the long tubular woven bag (4) with a special shape by press-fitting the filling (6) is designed to efficiently load the building (1). In order to receive it well, it is fixedly integrated (7) on the entire lower surface of the foundation (2). In Japan, where about 25% of the national land is dominated by soft ground, many ground improvement methods have been developed. However, the urban structure becomes complicated day by day, and a simple construction method in a narrower space is required. The present invention has been devised to meet this requirement, and is characterized in that after the construction of the present invention, it is possible to easily correct and restore the submerged portion, not just a slight amount that prevents subsequent subsidence.

[Brief description of drawings]

Fig. 1 Schematic diagram of the method of the present invention during construction Fig. 2 Schematic diagram of an example in which the woven bag used in the method of the present invention has a special shape when the contents are filled with filling material Fig. 3 Fig. 3 of the method of the present invention Schematic diagram of the process of pulling out the injection pipe while filling the woven bag with the filling in the course of the process. Fig. 4 Completed drawing of the present invention Detail 1, Building 2, Existing foundation 3, Constricted hole 4 Woven bag 5, filling material injection pipe 6, filling material that solidifies over time 7, solid integrated part

Claims (1)

[Claims] For uneven settlement of an existing building caused or that may occur due to soft ground, the ground just below the foundation of the building is pierced and woven in such a way that it swells into a special shape A method in which a tubular woven fabric bag is inserted, and a filling material that solidifies over time is pressed into the bag to improve the ground to resist the load of the building.