JPS6113048B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ground improvement method using a two-component mixed ground improvement chemical.

Conventional construction methods of this type are, for example,
As stated in the publication, a discharge port that independently communicates with the outside from the inner pipe and the outer pipe is provided at a predetermined height position of a double pipe consisting of both an inner and outer pipe, and a discharge port is provided on the outer periphery of the part where the discharge port is installed. An injection tube in which an annular elastic plate is integrally wrapped is used, and a discharge port fitting equipped with the annular elastic plate and an outer tube connecting cylinder protrude from the outer periphery of the injection tube. cannot be directly press-fitted into the ground, and is inserted into a pit excavated into the ground by pressurized water injection or other excavation means, or a pit protected by a casing pipe,
Not only is the construction complicated, but the surrounding ground is disturbed as the shaft is excavated, and the ring-shaped elastic plate is simply fitted to the discharge port hardware so as to cover the discharge hole of the same. Because it is not fixed to the same hardware,
The soil improvement chemical solution pressed out from the discharge port is injected into the outer peripheral ground through the gap formed between the elastic plate bulged in the outer circumferential direction by the discharge pressure and the peripheral surface of the discharge port hardware, and the injection directionality is Therefore, construction reliability is poor.

The present invention has been proposed in view of the above circumstances, and is arranged concentrically with an outer tube for injecting liquid A and an inner tube for injecting liquid B of a two-component mixed ground improvement chemical solution, and the outer tube is The upper tube has an annular recess on its outer peripheral surface, and the upper tube continues into the upper pipe and has a cutting blade at its lower end, and an annular protrusion that surrounds the outer peripheral surface of the lower end of the annular recess is protruded from the upper end edge. It consists of a lower tube with the same diameter as the upper tube, and the annular concave cavity is connected to the hollow parts of the outer tube and the inner tube through liquid A injection holes and liquid B injection holes, respectively, and rubber, etc. are connected to the annular concave cavity. An elastic annular body made of the above-mentioned outer tube is fitted so as not to protrude from the outer circumferential surface of the outer tube, and a lower end of the annular body is clamped between the outer circumferential surface of the recess and the annular protrusion of the lower tube. After the injection pipe is press-fitted to a predetermined depth in the ground to be improved in an anhydrous state, the chemical solution for ground improvement is injected into the ground to be improved through the injection pipe with the injection pipe and the outer ground in close contact with each other. The purpose of this ground improvement method is to create a new and useful ground in which a two-component mixed ground improvement chemical can be efficiently and accurately injected into the required ground without disturbing the surrounding ground. The point is that it provides an improved construction method.

The present invention will be described below with reference to the illustrated embodiments.

The outer tube for injecting liquid A of the two-component mixed ground improvement chemical solution is composed of an upper tube 1 and a lower tube 3. An annular recess 2 is provided on the outer circumferential surface of the upper tube 1, and an outer circumferential screw thread is provided in the lower part of the outer tube. A lower tube 3 having the same diameter as the upper tube 1 is screwed onto the portion 1a, and a shoe 4 having a digging blade 4a on the outer peripheral surface of the tip is screwed onto the lower end of the tube 3.
The hollow part of the lower tube 3 is closed by the shoe 4. Further, from the upper end edge of the lower tube 3, an annular protrusion 3a that surrounds the outer periphery of the lower half of the annular recess 2 is protruded.

An inner tube 5 is disposed concentrically within the upper tube 1 of the outer tube, and the outer periphery of the lower end thereof is a stepped portion 1b provided at the inner periphery located in the middle of the annular recess 2 in the upper tube 1. The inner tube 5 is screwed onto the inner circumferential thread portion 1c disposed further downward, and the inner tube 5 communicates with the hollow portion of the lower tube 3 via the lower hollow portion of the upper tube 1. On the other hand, the hollow portion in the upper tube 1 above the step portion 1b is closed at its inner periphery and lower end by the outer circumferential wall of the inner tube 5 and the step portion 1b.

A liquid injection hole 6 and B that communicate the annular recess 2 with the hollow part a of the upper pipe 1 and the hollow part b of the inner pipe 5
A liquid injection hole 7 is formed in the peripheral wall of the upper tube 1, and an elastic annular body 8 made of rubber or the like is provided in the recess 2 so that the outer peripheral surface thereof does not protrude from the outer peripheral surface of the upper tube 1 and the lower tube 3. The lower end of the tube is fitted into the annular recess 2 and the annular protrusion 3a of the lower tube 3.

In the present invention, the chemical injection pipe is press-fitted into the soil to be improved to a predetermined depth without using water by using a shoe 4 having a digging blade 4a provided at its lower end in an anhydrous state.

At this time, since the elastic annular body does not protrude from the surface of the outer pipe, it does not become an obstacle when the injection pipe is press-fitted, and the injection pipe is smoothly press-fitted into the ground, and the earth and sand are not inserted into the injection holes 6 and 7. Entry is prevented.

Furthermore, since the injection pipe is press-fitted into the ground under anhydrous conditions, it does not disturb the surrounding ground, and almost no gap is created between the injection pipe and the outer circumferential ground.

By immediately injecting liquids A and B from both the inner and outer pipes while the injection pipe is in close contact with the outer ground, each liquid passes through the injection holes 6 and 7 and moves through the elastic annular body 8 in the radial direction. It is pushed out and injected into the outer ground through the gap between the outer pipe and solidified, and when solidifying and improving the same ground, as there is no gap between the injection pipe and the outer ground as mentioned above, the injected chemical solution is not wasted. Injected into the surrounding ground.

At this time, since the lower end of the elastic annular body 8 is clamped by the annular recess 2 and the annular protrusion 3a of the lower tube 3, the elastic annular body 8 is able to hold the injectable drug. Due to the pressure of By being
Highly reliable construction becomes possible.

Furthermore, the A liquid and the B liquid pressed out from each of the injection holes 6 and 7 are sufficiently mixed while passing through the gap between the elastic annular body 8 and the upper pipe 1, and are reliably mixed when injected into the outer peripheral ground. The annular body 8 prevents the chemical liquid once injected into the outer ground from flowing back into the pipe, and there is no risk of solidification within the pipe.

As described above, according to the method of the present invention, the injection pipe for the two-component mixed ground improvement chemical is press-fitted into the ground to be improved in an anhydrous state, so the surrounding ground is not disturbed.
There is no gap between the outer tube and the ground, so there is no loss of the injected chemical solution, and the elastic annular body that covers the chemical injection hole is fitted into the annular recess provided in the outer tube so that it does not protrude beyond the outer circumferential surface of the outer tube. The lower end of the elastic annular body is connected to the annular recess and the upper end annular protrusion of the lower tube of the outer tube surrounding the recess. Since the chemical solution is clamped and fixed by the annular body, the chemical solution is injected into the outer ground only from the gap between the upper end of the annular body and the annular recess, giving directionality to the chemical solution injection and ensuring reliable construction. The invention has many advantages.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to these embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing one embodiment of a chemical injection pipe for ground improvement used in the method of the present invention. DESCRIPTION OF SYMBOLS 1... Upper pipe, 2... Annular recess, 3... Lower pipe, 3a... Annular protrusion, 4... Shoe, 4a... Excavation blade, 5... Inner tube, 6... A liquid injection hole ,7...B
Liquid injection hole, 8...Elastic annular body.

Claims (1)

[Claims] 1. An outer tube for injecting liquid A and an inner tube for injecting liquid B of a two-component mixed ground improvement chemical are arranged concentrically, and the outer tube has an upper tube having an annular recess on its outer circumferential surface, and It consists of a lower tube having the same diameter as the upper tube, which is connected to the upper tube and has a digging blade at the lower end, and has an annular protrusion projecting from the upper edge to surround the outer peripheral surface of the lower end of the annular recess. The recess is connected to each hollow part of the outer tube and the inner tube through a liquid A injection hole and a liquid B injection hole, respectively, and an elastic annular body made of rubber or the like is placed in the annular recess so as not to protrude from the outer peripheral surface of the outer tube. At the same time, the lower end of the annular body is clamped between the outer circumferential surface of the recess and the annular protrusion of the lower pipe, and the injection pipe is heated to a predetermined depth in the soil to be improved in an anhydrous state. A ground improvement method characterized in that after injection, a ground improvement chemical solution is injected into the ground to be improved through the injection pipe while the injection pipe and the outer peripheral ground are in close contact with each other.