JP2741643B2 - Liquefaction control ground and its construction method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved ground for suppressing liquefaction and a construction method thereof.

[0002]

2. Description of the Related Art The liquefaction of the ground is liable to occur in the sand ground, but such liquefaction countermeasures include a method of increasing the density of the sand ground, a method of changing the particle size distribution of the sand ground (replacement, etc.), There are methods of dissipating pore water pressure and methods of consolidating the ground.

[0003] Among them, the method of consolidating the ground is called a mixing treatment method, which includes consolidating the ground with a solidifying material such as cement. This mixing method is a surface mixing method in which the improvement material is extracted on soft ground and mixed with the surface soft soil to create solidified soil, and a mixing method and agitating blades that perform mixing by high-pressure jet injection. It is divided into the deep mixing processing method by the method of mechanically mixing and using.

[0004] These mixing methods are intended to solidify the entire ground so as not to cause liquefaction, and are economically relatively expensive, but are subject to a large earthquake in comparison with other methods. Can also be addressed.

[0005]

FIG. 6 shows a sandy ground 1 entirely solidified by using a solidifying material of cement. This is a reliable countermeasure against an earthquake, but is economical. It is very expensive.

For this reason, as shown in FIG. 7, a solidified wall body 2 which is continuous with a sand ground 1 to be liquefied is arranged in a lattice or polygonal shape when viewed from above, and the sand ground 1 is thereby formed. A method of restraining the occurrence of liquefaction by restraining the same has also been proposed.

[0007] However, if the space between the unsolidified grounds is too wide, or if the depth is too large, the wall thickness is thin and the strength is low, the ground will sway left and right in an earthquake or the like, the binding force will be lost, and the pore water pressure will increase. In addition, when the consolidated wall 2 is shaken in the lateral direction, cracks or distortion are generated, and the wall 2 is broken, and the intended prevention of liquefaction cannot be maintained.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned disadvantages of the prior art, and to prevent a liquefaction-inhibiting ground in which a solidified wall provided in the ground can reliably prevent liquefaction without shaking due to an earthquake or the like. To provide a construction method.

[0009]

According to the present invention, first, in order to achieve the above object, first, vertical solidification walls are formed at appropriate intervals in the ground, and the vertical solidification walls are provided between the vertical solidification walls. Arranging the plate-like diagonal compacts in a streak shape, and dividing the ground into small sections by these vertical consolidation walls and the plate-like diagonal compacts. Injecting the improved material at ultra high pressure from
The vertical solidified wall is machined at appropriate intervals in the ground by high-pressure jet injection mixing processing method that mixes and replaces the soil particles and grout at the same time as cutting the ground, and this vertical solidified wall By inserting a rod diagonally from the top of the ground into the ground, etc., the plate-like diagonal solidified body is streaked between the vertical solidified wall bodies by the same mechanized construction as that for the vertical solidification wall body. Thirdly, the vertical solidified walls are formed at appropriate intervals in the ground by a deep mixing method of solidifying a deep portion by mechanically stirring and mixing, and thirdly. The mechanized construction, such as inserting a rod diagonally into the ground from the top of this vertical compacted wall body, by the same mechanized construction as the construction of the vertical compacted wall body, a plate-shaped diagonal compacted body So as to be arranged between the vertical consolidation walls in a staggered manner. It is an Abstract that construction Te.

[0010]

According to the first aspect of the present invention, the vertical solidified wall itself partitions the ground and exhibits a water-blocking effect. Even if lateral flow occurs, the erected position can be maintained even if lateral flow occurs, and the solidified body in the oblique direction is plate-shaped, Since the ground between the solidified walls in the vertical direction is further partitioned, the restraining force on the ground between the vertical solidified walls is extremely high, and liquefaction can be completely prevented.

According to the second aspect of the present invention, a high-pressure jet injection / mixing method is used in which the improving material is jetted from the lower end of the rod at an ultra-high pressure, and the ground is cut and, at the same time, the soil particles and the grout are mixed and stirred or replaced. , And claim 3
According to the present invention described, by mechanical stirring and mixing, by the deep mixing processing method of solidifying the deep part, in any case, the construction of the vertically consolidated wall and the obliquely consolidated body Since the method is the same, the continuity of both constructions is good, which can contribute to shortening the construction period, and the finished product has the same material for the vertically consolidated wall and the obliquely consolidated body. As a result, the integrity and bonding strength are high, and the binding force of the entire wall to the ground can be increased, so that thorough measures against liquefaction can be taken.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of the joint structure of the liquefaction-inhibiting ground of the present invention.

First, the construction method will be described. As shown in FIG. 2, a vertical solidified wall 3 is constructed on a sand ground 1 at appropriate intervals. The vertical solidified walls 3 are combined so as to have a continuous lattice or polygonal shape when viewed from above as in the related art. The vertical consolidation wall 3 is generally used at present, and an improving material (grout) is sprayed from the lower end of the rod at an extremely high pressure to cut the ground and simultaneously mix and stir the soil particles and grout, or High-pressure jet injection mixing method to replace, mechanical stirring and mixing are performed, and mechanized construction is performed by the deep mixing method to solidify the deep part.

Next, as shown in FIG. 3, a rod is inserted obliquely from the upper part of the vertical solidified wall 3 into the ground, and the same mechanized construction as that of the vertical solidified wall 3 is performed. To form the solidified body 4 in the oblique direction. The diagonal solidified body 4 is a column-shaped solid body which is continuous in a plate shape. As shown in FIG.
Arrange them in a strut with a cross between them.

Therefore, the opposing vertical solidified walls 3
One of them joins the upper side of the obliquely compacted body 4 along the upper side thereof, and the other longitudinally consolidated wall body 3 forms the obliquely consolidated body of the lower side obliquely. 4 will be joined.

In this manner, the sand ground 1 is composed of the vertical solidified walls 3 and the bracing diagonal solidified bodies 4 disposed between the vertical solidified walls 3. A coupling structure is provided.

The vertical solidified wall 3 is formed as a wall by continuously forming columnar bodies.

The surface layer is provided with a ground improvement layer 5 or a pavement by a surface mixing treatment method.

When an earthquake or the like occurs, the sand ground 1 is subjected to horizontal and diagonal forces by the diagonally solidified body 4, and the vertically solidified wall 3 is greatly deformed. Never. As a result, the entire sand ground 1 can be sufficiently restrained.

[0020]

As described above, the liquefaction-inhibiting ground of the present invention and the method of construction thereof can reliably prevent liquefaction without shaking the solidified wall provided in the ground due to an earthquake or the like. Things.

[Brief description of the drawings]

FIG. 1 is a perspective view showing one embodiment of a liquefaction inhibiting ground according to the present invention.

FIG. 2 is a side view of a first step showing a method for constructing a liquefaction-inhibiting ground according to the present invention.

FIG. 3 is a side view of a second step showing a method for constructing a liquefaction-inhibiting ground according to the present invention.

FIG. 4 is a side view of a third step showing a method for constructing a liquefaction-inhibiting ground according to the present invention.

FIG. 5 is an explanatory diagram illustrating an operation of the liquefaction-preventing ground of the present invention at the time of an earthquake.

FIG. 6 is a perspective view showing a conventional example.

FIG. 7 is a perspective view showing another conventional example.

FIG. 8 is an explanatory diagram illustrating an operation at the time of an earthquake in a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sand ground 2 ... Solidified wall body 3 ... Vertically consolidated wall body 4 ... Diagonal solidified body 5 ... Ground improvement layer

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-181817 (JP, A) JP-B-56-37371 (JP, B2)

Claims (3)

(57) [Claims] 1. A vertical consolidation wall is constructed at an appropriate interval in the ground, and a plate-like diagonal consolidation body is arranged between these vertical consolidation walls in a streak shape. A liquefaction-inhibiting ground, wherein the ground is divided into small sections by a vertically consolidated wall and a plate-like obliquely consolidated body. 2. A high-pressure jet injection mixing method in which an improved material is jetted from the lower end of the rod at an ultra-high pressure to mix and agitate or replace soil particles and grout while cutting the ground, and to vertically separate the ground into the ground at appropriate intervals. The consolidation wall is mechanized, and a rod is obliquely inserted into the ground from above the vertical consolidation wall, and the plate-shaped diagonal is formed by the same mechanization as the construction of the vertical consolidation wall. A method for constructing a liquefaction-inhibiting ground, characterized in that a solidified body in one direction is arranged between the vertical solidified walls in a staggered manner. 3. A vertical solidification wall is machined at appropriate intervals in the ground by a deep mixing method in which a deep portion is solidified by mechanical stirring and mixing. By inserting a rod diagonally into the ground from the top of the body, the same mechanized construction as the construction of the vertical consolidation wall is performed, and a plate-like diagonal consolidation body is interposed between the vertical consolidation walls. A method for constructing liquefaction-inhibiting ground, characterized in that it is constructed so as to be arranged in a streak shape.