JPS6051221A - Stagewise soil improvement work involving excavation and chemical grouting - Google Patents

Abstract

PURPOSE:To additionally inject chemical grout as needed by confirming the injecting range of chemical grout by a method in which a swivel for multiple tube having an electric signal terminal, a rod incorporated with a cable conduit, and a rod having outer wall with electrodes are connected to one another. CONSTITUTION:A rotary rod for connection with electrodes, provided with a swivel for multiple tube having an electric signal terminal 1, a rotary rod for connection in which a cable conduit is provided in the multiple tube, and a cable conduit in which electrodes are provided to the outer wall, is connected to a drilling and chemical grouting monitor 23. When a conductor 26 comes into contact with the ground excavated, an excavating fluid in the inside flow path 28 is jetted to the direction of excavation. When the rod is pulled up after a given depth is reached, the fluid in the inside flow path 28 and the fluid in the outside flow path are mixed in a discharge path 35, and the chemical grout is injected from all-around slits 36. The injecting range of chemical grout is confirmed from the lowering of electric resistance by flowing electric current in the terminal 1, and chemical grout is additionally injected as needed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method for confirming the range of chemical injection in ground stabilization work by chemical injection (hereinafter referred to as chemical injection), and adding additional chemical at a desired location at any time when the chemical injection condition is insufficient. This is a ground improvement method that allows free digging and chemical pouring.

The method of pouring chemicals into the ground is rapidly developing because it is an effective method for increasing the strength of soft ground or stopping water.

Various ground improvement methods have been used for a long time, but currently, the single pipe method uses medium pipe rods or single pipe strainers, and the double pipe double packer injection or double pipe or sextuple pipe method. It can be broadly divided into multiple pipe construction methods that use rod injection.

These methods are easy to work with because drilling and pouring are done using the same iron. 7. Starting with the single-tube rod injection method, which is said to be the cheapest method, various purposes have been successively added to it, or complexity has been added in hopes of achieving a specific purpose or effect.

On the other hand, various proposals have actually been made, including the investigation of injection pipes, in pursuit of simplification or reliability of the drilling of the ground to be improved and the subsequent chemical injection work.

However, because various factors such as the complexity of the ground layer to be constructed, groundwater trends, type of injection storage agent, injection pressure, injection method, and differences in gel time are intertwined, -
The only way to accurately judge the injection status is to quietly check the injection/situation] ~ There is still no perfected technology for dealing with it.

In view of this point, the inventors of the present invention have conducted extensive studies, and have carried out the excavation of the ground and chemical injection work using a combination of a specific chemical injection pipe device, and also measured the chemical injection area during the construction period. We have established a construction method that allows additional chemical injection for areas where construction is insufficient.

That is, the present invention provides a multi-pipe swivel having electrical signal terminals, a connecting rotary rod in which cable conduits are arranged in the multi-pipe tubes, and a connecting rotary rod with electrodes in which cable conduits are arranged on the outer wall. Connect the required number of each and secure a flow path at the tip to send the two liquids separately at least until they reach the mixing area, and keep the inner pipe fluid open to the discharge flow path at all times, and the flanged conductor will be able to absorb its own weight in the longitudinal direction of the shaft. A chemical feed pipe monitor includes a piston disposed within the piston so as to be able to be drawn out and locked by a flange, and when the conductor is pushed into the piston, the inner pipe fluid flows out from the tip of the monitor as drilling water; When the conductor is drawn out, the piston is pushed down by the increase in internal pipe pressure, opens the small hole connecting the piston chamber and the discharge passage, and guides the conductor into the discharge passage, where both liquids are brought into contact and mixed, all around the circumference. This relates to a ground improvement method in which drilling and chemical injection are carried out in stages while measuring the electrical resistance in the ground by installing a drilling and chemical injection monitor that discharges the chemical to the outside of the pipe through a slit.

The configuration of the excavation/chemical injection pipe device used in the construction method of the present invention will be specifically explained below with reference to the drawings.

FIG. 1 shows a five-ply tube swivel, in which two terminals 1 are provided at the head of the swivel, insulated from the surroundings by an insulator 12. This terminal 1 is connected by a sliding brush 4 to a rotating terminal 6 provided on the outside of an electrode spindle which is rotatable around an axis and held watertight inside the tube part, and A lead wire (not shown) is drawn out from the inside and connected to a suitable connection terminal such as a cable connector at the lower end of the swivel via a cable conduit (not shown) provided at the center of the swivel shaft.

The middle tube 5 is intended to ultimately form a fluid flow path 7 between it and the swivel mantle g6, and its crown portion forms a closed path above the fluid intake port 8. .

A coaxial inner tube 9 is disposed inside the middle tube 5, forming a second fluid flow path 10 between it and the middle tube 5, and the top portion of the inner tube 9 is connected to the second fluid intake port 11. A closed circuit is formed at the ni part.

The middle tube 5 and inner duplex 9 are connected to the O-IJ ring 15 at appropriate locations. It is rotatably or integrally supported by a ball bearing 14, a U-cup 15, and an oil seal 16.

The ends of the swivel jacket tube, middle tube, and inner tube are each plugged or socketed for connection to the injection tube rod (triple tube).

If a slight margin is allowed in the length of the connecting portion at the end of the cable, such as a cable connector (not shown), it will be easier to connect the cable connector when connecting the injection pipe rod.

FIG. 2 shows the injection tube rod 17, but the cable conduit located at the center of the axis is omitted for the sake of simplification of the drawing. Outer tube 18, middle tube 19, and inner tube 20 that constitute injection tube rod 17
Both end edges are provided with sockets and plugs so that they can be connected to other members in a continuous manner.

FIG. 3 shows an injection tube rod 22 with an electrode provided with an electrode 21 on the outer wall of the tube.
As in FIG. 2, the illustration of the cable conduit is omitted. In this case too, is Rondo 4? ? The outer tube consists of
The ends of the middle tube and inner tube are processed into sockets and plugs in the same way as those shown in FIG. 2.

In the case shown in Fig. 5, one lead wire led out from the cable conduit passes through the ε dollar tube, extends to the outer tube, and is connected to the electrode 21 terminal on the outer wall of the outer tube. There is.

FIG. 4 shows a state in which the piston 27 of the drilling/chemical injection monitor 23 attached to the tip of the chemical injection pipe as described above is lowered (that is, a state in which the conductor 26 is in contact with the lowering seal body 37 due to its own weight). It is shown on the left side of the center line, and the time of drilling is shown on the right side.

To explain the functions of the device used in the present invention, the swivel,
Connect injection tube rod 1f, electrode to injection tube rod 22 and monitor 26] 7 First: tl! When excavating a + ground, the conductor 26 comes into contact with the excavated ground and slides inside the piston 27, resulting in the state shown on the right side of FIG. 4. Here, when the drilling fluid is passed through the inner flow path 28, the fluid flows through the conductor 26.
The piston 27 is
(At this time, the piston 27 is pushed up to the fourth right position by the expansion force of the spring 30.) It is ejected in the excavation direction through the gap 31, 32 between the piston 27 and the piston 27 to smoothly perform the excavation work.

Note that a very small portion of the liquid passing through the inner flow path 28 always flows out from the small hole 34 to the discharge flow path filter 4 through the minute gap 33, and of course always overflows from the circumferential slit 56. . As a result, external slime will not flow in and block the circumferential slit 56 during ground excavation and drainage.

When excavation is carried out to the specified legal level as described above,
When the rond's deposit and withdrawal are temporarily stopped, and on the contrary, the 11th do is raised at least a little more than the length of the conductor 26, the conductor 26 is paid out by its own weight, and its collar 29 comes into contact with the seal body 37 of the piston 27. , it can no longer pass through the gap 2.

If liquid continues to be pressurized into the inner flow path in this state, the piston 27 will act to compress the spring 50 as the internal pressure increases, and the wall of the piston 27 will eventually close to the small hole 58.
When opened, it becomes the state shown on the left side of Figure 4.

Therefore, the liquid passing through the inner flow path 28 passes through the small hole 38 and reaches the discharge flow path 34, where it comes into contact with and mixes with the liquid from the outer flow path discharged from the small hole 34 in the discharge flow path 65, and then passes through the entire circumference slit. The chemical solution is uniformly injected from 36 in all directions.

After the desired chemical injection is completed in this manner, when the rond is pushed into the ground again, the conductor 26 slides inside the piston and rises, and its collar 29 separates from the seal body 57, opening the gap 62. The pressure inside the piston 27 decreases, the expansion force of the spring 60 is restored, the piston 27 is pushed up, the small hole 38 is closed, and the state button on the right side of FIG. 4 is pressed to reproduce the soil excavation position.

With the construction method of the present invention, the following construction can be performed using the above-mentioned equipment.

That is, first, excavation is performed without rotating the pipe, and each time (or continuously) a current with a voltage of about 6 to 12 V is applied from an external power source to terminal 1 of the swivel head to dig into the untreated ground. After measuring the electrical resistance of the area and injecting the chemical solution, measure the electrical resistance again and judge the injection area based on the degree of decrease in resistance value.If necessary, add additional injections to the area where the chemical was previously injected. By doing so, you can ensure that the construction work is complete.

Many of the conventionally proposed differential pressure valve type double-pipe chemical injection pipes perform chemical injection after excavating the ground; However, once the chemical solution has been injected, the operation of the spring system and other valve sliding parts may become sluggish, causing ground excavation.
In practice, it was difficult to repeat the process of chemical dosing, drilling, and chemical injection, but with the monitor used in the method of the present invention, the chemical liquid that comes into contact with the piston is substantially the same as water, and it is difficult to carry out repeatedly. , and since solidification of the chemical solution does not occur here, there is an advantage that the vertical sliding of the piston can be performed any number of times without any hindrance.

Water may be used as the liquid to be pumped out during excavation, but for example, a slow-hardening chemical solution with a long gel time of about 10 to 20 minutes may be used as the excavation medium to soften the soil around the excavated area. After preliminary curing and stabilization, chemical injection, which is the original construction process, can be performed.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the swivel according to the present invention, FIG. 2.6
The figure is a sectional view □ of the injection tube rod, and FIG. 4 is a sectional view of the monitor. 1...Terminal, 5...Middle tube, 8...Fluid intake port, 9...Inner tube, 11...Fluid intake port, 17...Injection tube Rondo, 22...Electrode number Injection tube rond, 26...Monitor, 26...Conductor, 27...Piston, 29...Brim, 60...Spring, 61-33...Gap, '55...Discharge channel , 66... Full circumference slit, 67... Seal body agent Patent attorney Sanro Kimura 1 Figure 2 Figure 3

Claims (1)

[Claims] A swivel for multiple pipes with terminals for electrical signals, a rotary rond for connection in which cable conduits are arranged in multiple pipes, and an i
Connect the required number of t-poles to the rotary connecting electrodes with cable conduits, and secure a flow path at the tip to send the two liquids separately at least until they reach the mixing area to keep the inner pipe fluid flowing. A piston is placed inside the drug injection pipe monitor so that the fine flow path is always open to the discharge flow path, and the flanged conductor is drawn out by its own weight in the direction of shaft extension and is locked by the flanges. In preparation for this, when the conductor is pushed into the piston, the fluid in the inner tube flows out from the tip of the monitor as drilling water, and when the conductor is paid out, the piston is pushed down by the increase in pressure in the inner tube, connecting the piston chamber and the discharge flow path. A small hole is opened and the liquid is guided into the discharge channel, where both liquids are brought into contact and mixed, and then discharged outside the pipe through a slit all around the circumference.The electrical resistance in the ground is measured by installing a drilling and chemical injection monitor. 5 Ground improvement method in which excavation and chemical injection are carried out in stages.