JPH05287722A - Method of ground improvement - Google Patents

Abstract

PURPOSE:To execute ground improvement in a comparatively short term by a simple quick safe operation and obtain a ground having stable bearing power and the column load thereof is being dispersed. CONSTITUTION:The ground 14 is excavated and a foundation ground 11 is formed, a space truss 12 is constructed on the foundation ground, and the foundation ground 11 is filled back or improved. A structure is built while column load is received at the contacts of the space truss.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method for improving the ground on which a structure is installed so that a stable bearing force can be obtained.

[0002]

2. Description of the Related Art The foundation for safely transmitting the load of a structure to the ground is the most important part in the construction of the structure. Furthermore, to build this foundation, support of the foundation ground below the bottom of the foundation is required. It is necessary to increase the force sufficiently, and it is important to devise it so that uneven settlement does not occur.

Therefore, conventionally, as shown in FIG.
For example, a method of driving 60 PC piles 1 each having a diameter of 700 mm and a length of 33 meters into the ground 2 at a constant distance, and building a structure 3 on these PC piles 1 as a foundation. Alternatively, as shown in FIG. 5, concrete 5 is placed on a foundation ground 4 formed by excavating the ground 2 to a certain depth to improve the ground and construct a structure 3 on the concrete 5. A method for doing so has been proposed.

[0004]

However, according to such a conventional ground improvement method, in the case of using the PC pile, the long and expensive PC pile 1 is transported to the site, and the large-scale pile driving machine is used. However, there is a problem that the work is large-scale, a large work space is required, the construction cost is extremely high, and noise pollution is caused.

Further, in the method of placing concrete 5, if the construction scale is the same as the above, the construction cost is, for example, 1 /
Although it was 6 and it was cheap, there were problems such as poor durability. The present invention has been made by paying attention to the conventional problems as described above, and the ground can be easily and inexpensively formed by a simple and quick assembling work, and the ground having a desired sufficient proof strength. It is an object of the present invention to provide a ground improvement method for constructing a structure capable of forming a ground.

[0006]

In the ground improvement method according to the present invention, the ground on which a structure is installed is excavated to a certain depth to form a foundation ground, and a steel material (steel pipe or H
After building a space truss with steel or PC members,
By filling back the foundation ground or improving the ground, the structure can be constructed on the space truss so as to receive the column load at the contact point of the space truss.

[0007]

In the space truss according to the present invention, for example, the column load of the structure is applied to the apexes of the pyramids, which are the upper points of the plurality of diagonal members, and the column loads are distributed to the plurality of diagonal members and are evenly distributed on the foundation ground. Extend to. This makes it possible to effectively prevent uneven settlement of the foundation with a simple and inexpensive assembly.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a construction process diagram showing a ground improvement method for a three-dimensional truss according to the present invention. In FIG. 1, 11 is a foundation ground formed by excavating a ground 14 on which a structure is installed to a certain depth, and 12 is In this space truss for ground improvement established by assembling steel pipes and PC members on this foundation ground 11, the load from the pillars received at the apex of the pyramid which is the upper point is dispersed through the steel pipes which are diagonal members, Evenly spread over the foundation ground 11.

In addition, 13 is after setting the space truss 12 and after performing backfilling or ground improvement by concrete,
It is a structure constructed on the space truss 12.

Further, as shown in FIG. 2, the space truss 12 is formed by assembling a plurality of steel pipes and PC members so as to form a plurality of continuous cubes or rectangular parallelepipeds, which is the upper grade. A plurality of diagonal members 12a having the contact points P as vertices are arranged in a pyramid shape, and the upper chord members 12 are provided between the vertices P.
The lower chord member 12c of the lower portion is connected to the lower end of the diagonal member 12a. In addition, 12d is a vertical member for reinforcing the truss.

Next, the ground improvement method using the three-dimensional truss 12 will be described. First, the ground 1 where the structure is installed
4 is excavated to a certain depth and solidified to form a foundation ground 11 as shown in FIG. 1a. The foundation ground 11 is hardened as described above in order to sufficiently increase the supporting force, and prevents the foundation and the structure from being affected by the uneven settlement of the ground.

Next, the foundation ground 11 solidified in this way
A space truss 12 as shown in FIG. 2 which fits the bottom shape of the structure is installed on the top as shown in FIG. 1b. At this time,
Each contact point P of the space truss 12 is arranged at a position to receive the pillar of the structure. Also, each lower chord member 2c is firmly fixed on the foundation ground 11, and subsequently, the soil is refilled on the foundation ground 11 again to improve the ground. If necessary, instead of this backfilling, ground improvement may be performed by placing concrete or a ground improvement material. Therefore, the space truss 12 is partly or entirely buried in the earth and sand or concrete.

Subsequently, the structure 13 is constructed on the space truss 12 thus established on the foundation ground 11 so that each pillar is located at the contact point P, as shown in FIG. 1c. It

Therefore, each contact point P supports the pillar of the structure 13, and the entire structure 13 is supported on the space truss 12 as shown in FIG. 3, and at this time, one contact point from one pillar. If the load received by P is 70 tons, for example, a load of about 18 tons is distributed to each of the four diagonal members 2a extending downward from the contact point P in a quadrangular pyramid shape, and further, this load is passed through the lower chord member 12c. The entire foundation ground 11 is evenly burdened.

As described above, by simply using the space truss assembled with an inexpensive steel pipe or the like, it is possible to easily and inexpensively construct a ground having a sufficiently large strength and proof strength without using a large-scale pile driving machine as in the past. It can be formed, and by combining it with concrete pouring, a more stable supporting force can be obtained. Then, according to the space truss 12, it is easy to confirm the supporting force of the space truss 12, and in order to supplement the proof strength, it is optional to use pile driving together.

[0016]

As described above, according to the present invention, the ground on which the structure is installed is excavated to a certain depth to form the foundation ground, and the three-dimensional truss is formed on the foundation ground by the steel pipe or the PC member. After construction, backfilling to the upper foundation ground or improvement of the ground was performed, and it was made possible to construct the above structure on the above-mentioned space truss so as to receive the column load at its contact point. It is possible to obtain a stable bearing force that cannot be obtained by conventional ground improvement, and to realize this with inexpensive equipment and construction costs, simply by installing a simple three-dimensional truss.

[Brief description of drawings]

FIG. 1 is a construction process diagram showing a ground improvement method for a space truss according to an embodiment of the present invention.

FIG. 2 is a perspective view showing an embodiment of a space truss used in the present invention.

FIG. 3 is a structural diagram showing a relationship between a space truss and a structure according to the present invention.

FIG. 4 is a structural diagram showing a conventional ground improvement method.

FIG. 5 is a structural diagram showing another conventional ground improvement method.

[Explanation of symbols]

 11 Foundation Ground 12 Space Truss 13 Structure P Contact

Claims (1)

[Claims] 1. A foundation ground is formed by excavating the ground on which a structure is installed to a certain depth, and a steel material or P is formed on the foundation ground.
After constructing a three-dimensional truss with C members, backfilling the foundation ground or improving the ground, and improving the ground so that the structure can be constructed on the three-dimensional truss so that a column load is received at its contact point. Construction method.