JP2006045847A - Soil improvement method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a soil improvement method for improving soil by constructing an underground consolidated body along an arbitrary path inclusive of a curved portion or a region extending in the horizontal direction, in a manner dispensing with drilling of a breakthrough in the ground. <P>SOLUTION: According to the soil improvement method, a drill hole h is drilled by means of an excavation rod 2 having flexibility, and an annular casing 4 is inserted into the drill hole h along the same while housing therein the excavation rod 2 having flexibility, by excavating the ground G around the excavation rod 2. Then the excavation rod 2 is drawn out, and a solidifier injection means 5 is inserted into the annular casing 4 to inject cutting fluid in the same. Thereafter the solidifier injection means 5 is moved toward the ground E while carrying out injecting operation of the solidifier C. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a ground improvement method for constructing a consolidated body in the ground to improve the ground. More specifically, the present invention relates to a ground improvement method for constructing an underground consolidated body having a portion extending in a horizontal direction (including a substantially horizontal direction).

  Conventionally, it has been said that the construction method to build the underground solid body in the horizontal direction cannot be constructed directly from the ground surface.

About such a construction method, when construction is performed from the ground surface, it is common to excavate the starting vertical hole and the reaching vertical hole and build an underground solid body between the starting vertical hole and the reaching vertical hole It is. That is, in order to carry out the construction method to build the underground solid body in the horizontal direction, excavate the start vertical hole and the reaching vertical hole, and drill the bore hole in the horizontal direction between them to fill the consolidated material There is no construction that directly drills a boring hole in the horizontal direction directly from the ground surface without excavating the starting and reaching holes.
Moreover, in the above-mentioned conventional technique performed by excavating the starting vertical hole and the reaching vertical hole, curve construction cannot be performed, and it is difficult to set a path for excavating and filling the solidified material along an arbitrary path.

Here, in recent years, a technique capable of excavating a predetermined curved path using a flexible excavation rod has been proposed (so-called “curved boring”). When such a technique is used, excavation is performed. Unless the rod tip is exposed (penetrated) to the ground side, it is difficult to build an underground solid body.
In other words, even if a predetermined curved path is drilled using a flexible excavation rod, in the so-called “blind hole” state, the drilled curved path is expanded to increase the underground solid body. Could not be created.

As another conventional technique, there is a technique for performing horizontal excavation and filling with a solidified material using an auger (see, for example, Patent Document 1).
However, with such a technique, it is impossible to excavate and fill the solidified material along a curved path.
Japanese Patent Laid-Open No. 10-183599

  The present invention has been proposed in view of the above-described prior art, and it is possible to improve the ground by building an underground solid body along an arbitrary path including a curved portion and a region extending in the horizontal direction. The purpose of the present invention is to provide a ground improvement method that does not require drilling of through holes.

The ground improvement method of the present invention uses a flexible excavation rod (excavation rod 2 used in so-called “curved boring”) (along a curved portion and an arbitrary path including a region extending in the horizontal direction). ) Drilling the boring hole (h) (a drilling process using the flexible rod 2; FIG. 1), and an excavating rod (2) in which the annular casing (sheath tube, special casing 4) is flexible. A step of inserting along the borehole (h) while excavating the ground (G) around the excavation rod (2) while accommodating the excavation rod (2), and flexibility A step of pulling out the excavation rod (2) having the shape (FIG. 4) and a step of inserting the solidification material filling means (monitor 5) into the annular casing (sheath tube, special casing 4) (solidification material filling means erection step) FIG. 5) and a cutting fluid (eg for cutting) And a step of moving the solidification material filling means (monitor 5) to the ground side (E) while injecting the water and injecting the solidification material (C) (solidification material filling step; FIG. 6). Item 1).
In the present specification, the term “horizontal direction” is used as a term including “substantially horizontal direction”.

Further, the ground improvement method of the present invention uses a flexible excavation rod (excavation rod 2 used in so-called “curved boring”) (in an arbitrary path including a curved portion and a region extending in the horizontal direction). Along the borehole (h) and the ground (G) around the excavation rod while the annular casing (sheath tube, special casing 4) accommodates the excavation rod (2) having flexibility. ) Is drilled along the boring (h) hole (the drilling step with the flexible rod 2 shown in FIG. 1 and the sheath tube inserting step shown in FIGS. 2 to 3 are simultaneously performed. Step), a step of pulling out the flexible excavation rod (2) (FIG. 4), and a step of inserting the solidification material filling means (monitor 5) into the annular casing (sheath tube, special casing 4), , Spraying cutting fluid (eg cutting mud) Solidifying material filling means while injecting hardening material the (C) (monitor 5) the ground side (E) a step of moving the (hardened material filling process; FIG. 6), and a city (claim 2).
In this case, a boring hole (h) drilled using a flexible excavation rod (excavation rod 2 used in so-called “curved boring”) accommodates the flexible excavation rod (2). On the other hand, an annular casing (sheath tube, special casing 4) is inserted along the bore (h) hole while excavating the ground (G) around the excavating rod, but slightly ahead.

  In the present invention, in the step of moving the solidifying material filling means (monitor 5) to the ground side (E) (solidifying material filling step; FIG. 6), the solidifying material filling means (monitor 5) is moved by a predetermined angle (for example, It is preferable that the rotation and the reverse rotation are repeated (for example, every 180 ° or 360 °, the rotation in the clockwise direction and the rotation in the counterclockwise direction are alternately repeated: swinging). 3).

Here, in the step of moving the solidification material filling means (5) to the ground side (E) (solidification material filling step; FIG. 6), the solidification material filling means (monitor 5) is moved by a predetermined angle (for example, 180 °). 360 °, etc.) Repeated rotation and reverse rotation (for example, every 180 ° or 360 °, alternately rotating clockwise and counterclockwise rotating: oscillating) without rotating clockwise or counterclockwise You may rotate to either one of the clockwise direction.
However, in that case (when rotating clockwise or counterclockwise), the rod (50) provided with the solidifying material filling means (5) at the tip, the solidifying material (cement milk) supply pipe (For example, a hose 6) and a cutting fluid (for example, muddy water, air) supply pipe (for example, a hose 7) so that the rod (50) and the hoses (6, 7) are not twisted. Etc.) must be provided.

  In the present invention, when the solidifying material filling means (monitor 5) is moved to the ground side (E) (solidifying material filling step; FIG. 6), the solidifying material filling means (monitor 5) is moved to the ground side (E). Each time, the annular casing (sheath tube, special casing 4) is preferably moved to the ground side by a distance that moves the solidifying material filling means (5) to the ground side (E).

  In carrying out the present invention, an annular casing (sheath tube, special casing 4) accommodates a flexible excavation rod (2) and drills the ground (G) around the excavation rod (2). In the step inserted along the hole (h) (sheath tube insertion step; FIGS. 2 to 3), a cutting fluid (for example, from the face side) of the annular casing (sheath tube, special casing 4) (for example, An area corresponding to a cross section of the annular casing (4) (a plane perpendicular to the traveling direction of the annular casing 4) is jetted (toward the front side of the annular casing). Is preferably excavated (claim 4).

  In the present invention, when a cutting fluid (for example, the cutting mud water J and Jc) is ejected from the solidifying material filling means (5), a predetermined portion (for example, a working face) of an annular casing (sheath tube, special casing 4) The slurry discharge fluid (for example, muddy water, air Ja, etc.) is ejected toward the ground side (E) from the side tip part, a part separated from the face side tip part by a predetermined distance to the ground side. (Claim 5).

According to the ground improvement method of the present invention, a flexible excavation rod (excavation rod 2 used in so-called “curved boring”) is used for any path including a curved portion and a region extending in the horizontal direction. Along the borehole (h) (drilling step with the flexible rod 2; FIG. 1), and the annular casing (sheath tube, special casing 4) is a flexible excavation rod ( 2) is inserted along the borehole (h) while excavating the ground (G) around the excavating rod (2) while accommodating (sheath tube inserting step; FIGS. 2 to 3). Once the casing (sheath tube, special casing 4) is arranged, even if the excavating rod having flexibility (the excavating rod 2 used in so-called “curved boring”) is recovered to the ground side (drawn), Drilled borehole (h Depending annular casing (sleeve pipe, special casing 4), it is protected from collapse or the like of the natural ground. Further, the solidifying material filling means (monitor 5) can be easily and reliably inserted.
Furthermore, in the course of the construction outward path, the borehole (h) protected by the annular casing (4) is expanded in diameter and filled with the solidified material, so that it is an underground solid body extending in the horizontal direction. In addition, a so-called “blind” underground solid body can be formed without opening the tip to the ground surface side.

  According to the present invention, since a flexible excavation rod (excavation rod 2 used in so-called “curved boring”) is used, it is not necessary to excavate the start vertical hole and the reaching vertical hole.

Further, as described above, since it is not necessary to expose the boring hole and the tip of the underground consolidated body to the ground surface side, it is possible to perform construction even at a site where such a through hole cannot be drilled.
Furthermore, even if the area | region extended in a horizontal direction is long, it can construct.

  In the step of moving the solidification material filling means (monitor 5) to the ground side (E) (solidification material filling step; FIG. 6), the solidification material filling means (monitor 5) is moved by a predetermined angle (for example, 180 °, 360 °). If rotation and reverse rotation are repeated (for example, every 180 ° or 360 °, the rotation in the clockwise direction and the rotation in the counterclockwise direction are alternately repeated: swinging) (claim 2) A rod (50) provided with a solidifying material filling means (5) at its tip, a solidifying material (cement milk) supply pipe (for example, hose 6), a cutting fluid (for example, muddy water, air) supply pipe (for example, hose 7) Will not twist.

  Further, in the present invention, a cutting fluid (for example, a cutting mud jet Jw2) is sprayed (toward the front side of the annular casing) from the tip (on the face side) of the annular casing (sheath tube, special casing 4). If the region corresponding to the cross section of the annular casing (4) is excavated (Claim 3), a flexible excavation rod (excavation rod 2 used in so-called "curved boring") ) Even if the boring hole (h) is excavated over a longer distance, the annular casing (sheath tube, special casing 4) that reliably protects the boring hole (h) from the collapse of the natural ground is It can arrange | position around the excavation rod (2) which has property.

Here, if the region extending in the horizontal direction is long (for example, 100 m or more), the slurry generated at the time of excavation is not discharged well to the ground side, so that there is a possibility that the construction becomes difficult.
However, in the present invention, if the slurry discharging fluid is jetted toward the ground side (Claim 4), the slurry is surely discharged even when the region extending in the horizontal direction extends over a long distance. Therefore, it is possible to create an underground solid body extending in the horizontal direction.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1-6 is process drawing explaining the construction process of the ground improvement construction method of embodiment. Based on the same figure, the structure and process of the equipment and machine which are required for construction are explained in order.

FIG. 1 shows a drilling process using a flexible rod (a drilling rod used in so-called “curved boring”).
The excavator 1 is disposed on the ground side E. The state shown in FIG. 1 is a flexible rod (excavation rod used in bending boring) 2 that is fed out from the excavator 1 at a predetermined angle, and digs obliquely forward to a predetermined depth. A state where the ground region G is dug horizontally and a borehole (boring hole) h is dug up to the reaching point is shown. Here, the drilling of the excavation hole (boring hole) h by the flexible rod (excavation rod used in bending boring) 2 can be performed along a desired path.

  2 and 3, in the sheath tube insertion step, the sheath tube (annular casing, special casing) surrounding the flexible rod 2 with the flexible rod 2 shown in FIG. 1 as a guide. ) 4 is inserted.

As shown in detail in FIG. 7, the annular casing 4 is configured by engaging element pipes 40 having protruding joint members 41 at both ends with the protruding connection members 41. The tip of the annular casing 4 cuts the element tube 40 at the center in the longitudinal direction (the remaining half of the element tube is indicated by reference numeral 42), and details are shown in FIG. 8 and FIG. The nozzle member 43 shown is attached.
In addition, the annular casing 4 is configured to transmit tension and torque. In addition, it can replace with the cyclic | annular casing said here, and can also use a more flexible raw material, for example, the sleeve-shaped casing made from resin.

As shown in detail in FIG. 8, the nozzle member 43 has a cutting fluid ejection nozzle 44a with the direction of the injection hole directed forward, and the direction of the injection hole on the back surface of the cutting fluid injection nozzle 44a. A mud discharge fluid ejection nozzle 44b is attached in a direction away from the direction of the nozzle hole of the nozzle 44a.
The cutting fluid ejection nozzle 44a is connected to ground cutting fluid supply means (not shown) by a cutting fluid supply hose 45. Moreover, the fluid discharge nozzle 44b for waste mud is connected via, for example, a compressor (not shown) on the ground side and an air hose 46, and is configured to be supplied with high-pressure air.

  When the annular casing 4 is inserted, a cutting fluid (for example, cutting mud Jw2) is ejected from the cutting fluid injection nozzle 44a at the tip of the annular casing 4 so that the ground around the flexible rod 2 is moved to the annular casing 4. The cross section, that is, the surface perpendicular to the traveling direction of the annular casing 4 is excavated in an annular shape, and the annular casing 4 is inserted into the excavated portion.

Here, the annular casing 4 is necessary for securing the boring hole h drilled by the flexible rod 2 from collapse or the like.
Even if a large-diameter boring hole is drilled at the tip of the flexible rod 2, a cutting fluid jet nozzle (jet nozzle) 44 a, a mud discharge fluid jet nozzle 44 b and a drilling mud at the tip of the annular casing 4. The supply hose 45 and the drainage fluid (for example, high pressure air) supply hose 46 are necessary.
There is a possibility that the hole h drilled by the flexible rod 2 is not in a state where the annular casing 4 can be inserted due to collapse or the like. Therefore, excavation is performed at the tip of the annular casing 4 in accordance with the cross-sectional shape of the annular casing 4 so that the annular casing 4 can be inserted even if collapse occurs.
If the annular casing 4 is inserted, a solidification material filling means (monitor 5) described later can be inserted into the annular casing 4 and moved to the face side.

When excavation by the annular casing 4 and insertion of the annular casing 4 are completed, the flexible rod 2 is extracted to the ground side as shown in FIG. 4 (flexible rod extraction step).
Here, when the flexible rod 2 is pulled out, since the annular casing 4 has already been inserted, there is no possibility that the boring hole h cut by the flexible rod 2 will be blocked due to collapse or the like. .
In FIG. 4, for clarity of illustration, the annular casing 4 shows only a reference numeral, and the flexible rod 2 in the annular casing 4 is indicated by a solid line.

In the step of installing the solidifying material filling means (so-called “monitor”) in FIG. 5, the solidifying material filling means (hereinafter, the solidifying material filling means is referred to as a monitor) is inserted into the annular casing 4 and inserted to the tip.
As shown in the detailed view of FIG. 9, the monitor 5 is attached to the tip of the monitor operating rod 50, discharges the solidified material (cemented milk) C from the tip of the monitor 5, and is straight and parallel to the axis center on the side surface. It is configured to form a so-called cross jet Jcw in which a jet fluid Jw of cutting fluid (muddy water, air) sprayed from a pair of spray holes N, N formed on a line intersects at one point (described later) 11 and 12).
Alternatively, the jet J is ejected from the nozzle Ns formed on the side surface of the monitor 5 (FIG. 13).
The monitor 5 is connected to a hose 52 for supplying a solidified material (cement milk) and a hose 54 for supplying a cutting fluid (for example, muddy water or muddy water and air).

When the monitor 5 reaches the tip of the expanded borehole, the soil G around the hole is cut by the cutting fluid (muddy water or muddy water and air) sprayed from the monitor 5, and the solidified material C The annular casing 4 is pulled out to the ground side by a length L corresponding to a region filled with (an amount including a margin) (arrow Y1).
Depending on the state of the ground G, a tool (not shown) may be used for further drilling or excavation.

In the solidifying material filling step of FIG. 6, the monitor 5 is rotated 180 ° or 360 ° alternately in the clockwise and counterclockwise directions, and the counter rotation is repeated (the monitor 5 is rotated 180 ° or 360 °. Move).
The monitor 5 or the operation rod 50 is not rotated when the monitor 5 or the operation rod 50 is rotated, the cutting water or solidifying material (cement milk) supply hose 6, the cutting fluid supply hose 7 and the operation. This is because the use rod 50 is twisted.

In the illustrated embodiment, the monitor 5 is swung (turned) by 180 ° or 360 ° without rotating the monitor 5 or the operating rod 50. The angle of the swing or rotation, in other words, the swing (rotation) angle that reverses the rotation direction is determined so that a circular area can be excavated as described later. Although not shown, the swing angle is 120 ° when three pairs of nozzles N, N are provided on the monitor, and 90 ° when four pairs are provided.
However, the hose 6 for supplying cutting water or solidified material (cement milk), the cutting fluid supply hose 7 and the operation rod 50 are configured so as not to be twisted, or the rear end of the monitor 5 (ground It is also possible to attach the swivel joint to the side end) and rotate the monitor 5 or the operating rod 50.

  Thereafter, the annular casing 4 is pulled out to the ground side E by the length of the region determined by the construction procedure. Then, the special casing is pulled out by swinging (turning) the monitor 5 and pulling it out to the ground side E, that is, by repeating the swinging (turning) of the monitor 5 and the movement to the ground side E every predetermined distance. The ground G is cut with a cutting fluid around the annular casing 4 to increase the diameter, and the solidified material C is injected and stirred. Then, the expanded bore hole H is filled with the solidified material C. And the above-mentioned operation is repeated until a desired underground consolidated body is formed.

If the horizontal part is about 100 m, there is a risk that slurry (mud) will not be discharged to the ground side. Therefore, as shown in FIG. 10, a slurry discharge fluid (for example, air, for discharging slurry to the ground side from the above-described waste mud fluid injection nozzle 44b from the tip of the annular casing 4 toward the rear. Water).
FIG. 10 shows a state where a slurry discharge fluid (high-pressure air in FIG. 10) Ja for discharging the slurry to the ground side is jetted from the mud discharge fluid jet nozzle 44b.
The slurry is taken from the tip of the annular casing 4 to the discharge fluid (high pressure air) Ja and discharged to the ground side.
Note that an ejection mechanism for ejecting the slurry discharge fluid toward the ground side may be provided in the middle of the casing 4 (for example, a plurality of locations). Water may also be used.

  In FIGS. 11 to 13, while the monitor 5 is swung (rotated), a jet J (or a cross jet Jc) of a high-pressure cutting mud is ejected from a nozzle N provided on the side of the monitor 5. Shows a mode of excavating the surrounding soil.

In the embodiment of FIG. 11, the jet J jetted from the two pairs of nozzles N, N formed on the side surface of the monitor 5 is excavated with a cross jet Jc formed by crossing at a predetermined radial position. The swing (rotation) is configured to rotate in the opposite direction every time the rotation angle is rotated by 180 °, and as a result, swings by 180 °. In other words, in the embodiment of FIG. 11, if the rotation direction is reversed every time the monitor rotates (swings) by 180 °, an underground solid body having a circular cross section is formed.
In the embodiment of FIG. 12, the configuration is the same as that of FIG. 11, but since only a pair of nozzles N, N are formed on the monitor side surface, the monitor rocks for the formation of a cylindrical underground solid body. The movement (turning) is configured to reverse at 360 °.
FIG. 11 and FIG. 12 show an embodiment when it is necessary to accurately limit the excavation range (when the diameter of the excavation hole is improved).

  In the example of FIG. 13, unlike FIG. 11 and FIG. 12, an embodiment in which the jet J is injected from a single nozzle Ns instead of a cross jet, and it is not necessary to accurately limit the excavation range (comparison) This is an example of the case where the accuracy of the diameter of a general excavation hole is not questioned.

Here, the solidified material C sprayed from the tip of the monitor 5 is sprayed upward from the horizontal as shown in FIGS.
This is because the excavated hole formed in the ground is horizontal, so that the injected solidified material C is inclined in the lower part of the cross section of the hole, so that there is no gap in the upper part in advance. This is a result of considering the injection direction of the material C.

  According to the ground improvement method using the annular casing 4 and the monitor 5 as described above, it is possible to perform the same construction as the above on the curved excavation hole Hc in which the entire excavation hole has a curvature as shown in FIG. It is.

According to the embodiment of the present invention, the excavation start hole and the reaching vertical hole are not excavated, the tip exists in the ground (the tip is not exposed to the ground surface side), and the underground solid body having the horizontal portion is provided. Can form a knot.
In addition, construction is possible even at sites where the through holes cannot be drilled.
Furthermore, even if the area | region extended in a horizontal direction is long, it can construct.
When the underground consolidated body is formed, a rod 50 provided with a monitor 5 at the tip, a solidifying material (cement milk) supply pipe (for example, a hose 6), a cutting fluid (for example, muddy water, air) supply pipe (for example, The hose 7) is not twisted.
In addition, the slurry is surely discharged even if the region extending in the horizontal direction of the borehole h (or the underground solid body to be formed) is long.

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

Process drawing which shows the drilling process in embodiment of this invention. Process drawing which shows the middle of the cyclic | annular casing insertion process in embodiment. Process drawing which shows completion of the cyclic | annular casing insertion process in embodiment. Process drawing which shows the extraction process of the flexible rod in embodiment. Process drawing which shows the solidification material filling means standing-up process in embodiment. Process drawing which shows the solidification material filling process in embodiment. The side view explaining the detail of the cyclic | annular casing used by embodiment. The side view explaining the detail of the cyclic | annular casing front-end | tip part used in embodiment, and the aspect which injects the fluid for cutting. The side view explaining the structure of the periphery of the solidification material filling means used in the embodiment. The side view explaining the aspect which injects the fluid for mud discharge from the cyclic | annular casing front-end | tip part used by embodiment. The side view of one Example which injects cutting fluid. The side view of the 1st modification which injects cutting fluid. The side view of the 2nd modification which injects cutting fluid. The aspect figure which shows the construction example of the excavation hole in which the whole has a curvature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Excavator 2 ... Flexible rod (rod for bending boring)
3 ... reel 4 ... sheath tube / special casing 5 ... solidifying material filling means / monitor 6 ... cutting water or solidifying material supply hose 7 ... cutting fluid supply hose 41 ... -Joint member 43 ... Nozzle member 45 ... Cutting fluid supply hose 46 ... Air hose N ... Nozzle Jc ... Cross jet

Claims (5)

  Drilling a boring hole using a flexible excavating rod, and an annular casing accommodating the excavating rod having flexibility while excavating the ground around the excavating rod along the boring hole A step of inserting, a step of pulling out a flexible excavation rod, a step of inserting a solidifying material filling means into an annular casing, and a solidifying material filling means while injecting the solidifying material by injecting a cutting fluid A ground improvement construction method characterized by comprising a step of moving to the ground side.   A boring hole is drilled using a flexible excavating rod, and an annular casing accommodates the excavating rod having flexibility while excavating the ground around the excavating rod along the boring hole. A step of inserting, a step of pulling out a flexible excavation rod, a step of inserting a solidifying material filling means into an annular casing, and a solidifying material filling means while injecting the solidifying material by injecting a cutting fluid A ground improvement construction method characterized by comprising a step of moving to the ground side.   The ground improvement method according to any one of claims 1 and 2, wherein in the step of moving the solidifying material filling means to the ground side, the solidifying material filling means is repeatedly rotated and reversely rotated by a predetermined angle.   In the step in which the annular casing accommodates the flexible excavation rod and is inserted along the borehole while excavating the ground around the excavation rod, the cutting fluid is injected from the tip of the annular casing. The ground improvement construction method according to any one of claims 1 to 3, wherein an area corresponding to a cross section of the annular casing is excavated.   The ground according to any one of claims 1 to 4, wherein when the cutting fluid is ejected from the solidifying material filling means, the slurry discharging fluid is ejected from a predetermined portion of the annular casing toward the ground side. Improved construction method.

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