JP4467329B2 - Drilling method - Google Patents

Description

  The present invention relates to a drilling method in the case of vertical drilling, for example, ground improvement, pile driving, or construction of a continuous wall in the ground.

  Conventionally, as an equipment for drilling, for example, it has a fully swivel casing excavator and a self-propelled crane, and it can be operated while moving work is easy and the stability of the equipment is good. A drilling facility that can improve the efficiency of the entire excavation work including the work has been proposed (see, for example, Patent Document 1).

  As a method for drilling, a technique is known in which a rod is used and a ground is drilled from the tip of the rod, for example, by jetting high pressure water.

In the technique of drilling the ground with the above-described excavation equipment or high-pressure water jet, drilling is performed by applying a thrust force vertically downward with a casing or a rod.
However, in the prior art in which a thrust is applied vertically by a casing or a rod to drill a hole, when a hard ground or the like hits a location eccentric from the center line of the casing or rod in the drilling hole A bending force may act on the casing or the rod, and the tip portion may be tilted in a direction “shifted” from the vertical direction (a direction different from the vertical direction).
When such a situation occurs, there is a problem that a hole is drilled in a direction different from the purpose.

  In order to deal with such a problem, the rear end (ground side) of the casing for drilling is suspended by, for example, a feed wire, and the rod is suspended in the air with a jet of high-pressure water from the tip of the rod. More specifically, there has been proposed a technique of drilling by a hanging digging method in which a drilling hole is drilled in a suspended state without applying thrust to the drilling rod from above.

However, even in such a suspension digging method, that is, a suspension digging method in which a hole is drilled in a suspended state without applying thrust to the drilling rod from above, when the tip of the drilling rod comes into contact with the hard ground (bottom) In such a case, the suspended rod leans against the wall surface of the drilled hole. As a result, the desired vertical accuracy cannot be maintained in the drilling direction.
Furthermore, since it is impossible to grasp the situation (a situation where the desired vertical accuracy cannot be maintained in the drilling direction) on the ground side, the ground drilling can be continued in the same drilling direction. There is a risk that.

As such, when the underground G is drilled in a state where the vertical accuracy in the drilling direction is not ensured, the ground is improved by creating an underground solid body particularly in the deep underground region (large depth region). In that case, there is a possibility that an underground solid body may be formed at a position different from the planned area to be formed.
Further, for example, in order to construct an underground connection wall, when drilling, for example, six holes H as shown in FIGS. 19 and 20, the fifth hole H from the left is inclined to the right. In such a case, a portion that is not drilled as indicated by the symbol D, that is, a so-called “gap (portion where the soil is left)” is generated, and there is a possibility that the water stop required for the continuous wall is not ensured. Then, when such a gap D has occurred, a work of filling the gap D, that is, a work of re-drilling the portion where the soil G is left, that is, a so-called “squeezing” operation, occurs. Had the problem of delaying.
Particularly in recent years, the required depth in construction has become deeper, and the vertical accuracy in the drilling direction has become stricter. However, no drilling method that can meet such strict requirements has been proposed.
JP 2001-032663 A

  The present invention has been proposed in view of the above-described problems of the prior art, and an object thereof is to provide a drilling method capable of increasing the vertical accuracy in the drilling direction and adapting to drilling at a deep depth.

  According to the present invention, there is provided a cylindrical casing (1C) and a monitor (1M) provided in the casing (1C) having a nozzle that is provided at the lower end of the cylindrical casing (1C) and injects a jet (J) of high-pressure water. In the drilling method for forming a vertical drilling hole by lowering at a constant speed while rotating in a suspended state, the rod (1) has a rod (1) provided with a tip of the rod (1) Is provided with determination means (8, 30) for determining that it has come into contact with a hard ground portion (K) that cannot be drilled when lowered at a constant speed, and the tip of the rod (1) is lowered while being lowered at a constant speed. Is determined to have come into contact with the hard ground portion (K) by the determination means (8, 30), and the jet (J) is ejected from the nozzle in a state where the lowering of the rod (1) is stopped and stopped. Drilling a hard ground part (K), When the ground portion (K) is drilled and the determination means (8, 30) determines that the tip of the rod (1) is no longer in contact with the hard ground portion (K), the rod (1) is again inserted. It is designed to be lowered.

  Further, in the drilling method of the present invention, the determination means (8, 30) includes a hook (21) attached to an attachment (2) provided at an upper end of the rod (1), and the hook (21) has a hanging hook. (12) is engaged with a ring-shaped lifting tool (9), and the tip of the rod (1) is in contact with the hard ground portion (K) at the top of the attachment (2). A switch (8) that is pressed when the hanger (9) comes down is provided, and an electric wire block (10) that moves up and down the hanger (9) in response to a signal from the switch (8). It is comprised by the control panel (30) to control.

  The jet (J) ejected from the nozzle constitutes a cross jet (Jc).

  According to the drilling method of the present invention having the above-described configuration, drilling is performed using a high-pressure water jet (J). Therefore, when drilling is normally performed, the drilling means (1 ) Is always floating in the air, and the hole can be drilled in a state where only gravity is applied without giving any thrust that causes bending to the hole drilling means.

  If the drilling means (1) sinks under its own weight before the high-pressure water jet (J) is not sufficiently drilled, the drilling means (casing or rod: 1) is placed on the bottom surface of the drilling hole (H). There is a risk that the accuracy of drilling (accuracy with respect to the vertical) may deteriorate due to contact (bottoming). However, in the present invention, by setting the settling speed of the drilling hole in advance, the drilling means (1) balances the drilling speed with the settling speed of the drilling means (casing or rod: 1). It is possible to prevent the bottoming as much as possible.

In addition to this, the present invention deals with a case where the speed of drilling by the jet (J) becomes slower than the settling speed of the drilling means (casing or rod: 1) by the above method. I can do it.
In such a case, if it is detected by the bottom switch (8) that the hole drilling means (1) has bottomed, the descent of the hole drilling means (1) is stopped by the judging means (bottom switch: 8). The hole drilling means (1) is rotated at the same depth to jet a jet (J) from the tip. Therefore, in a stage before the suspended drilling means (1) is in a state of leaning against the wall surface of the drilled hole (H), the lower part of the drilling means (1) is jet (J). It is possible to prevent the drilling means (rod: 1) from leaning against the hole wall of the drilling hole at the bottom of the drilled hole (H).

  At the end of drilling, the lower part of the drilling means (jet injection part, monitor: 1M) is pulled out by pulling means such as a wire (in the example shown, the monitor 1M is lifted using the monitor removing device P). For example, a chemical solution injection tube can be built in the hole drilling means (casing: 1C).

  In addition, it can respond to the change of the drilling target ground and the wear of the nozzle part (not shown) at the tip of the drilling means (rod: 1) by replacing the lower part (monitor part: 1M).

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  First, a first embodiment will be described with reference to FIGS.

In FIG. 1, a rod 1 as a hole drilling means is composed of a cylindrical casing 1C and a monitor 1M having a nozzle for injecting high-pressure water provided at its lower end, and the monitor 1M is shown in FIG. As shown in FIG. 4 (FIGS. 3 and 4 will be described later), the inner periphery of the casing 1C is constrained so that the rotational direction is restricted via a spline, for example, and the vertical direction is movably locked. .
Returning to FIG. 1, an attachment 2 to which a high-pressure water supply line Lw is connected is attached to the rear end side, which is the ground side of the rod 1, so as to be relatively rotatable.

  In the middle of the rod 1, a boring machine 3 that surrounds the rod 1 and applies a rotational force to the rod 1 is installed by a support member (not shown).

  As shown in FIGS. 7 and 8, a pair of guide rollers 5 having a rotation shaft 51 and a guide roller support for supporting the guide rollers 5 are provided in an area between the boring machine 3 and the ground surface 4 of the rod 1. A casing (rod) rotating jig 7 composed of the member 6 is provided.

  The guide roller support member 6 includes a box-like body 61 whose lower side is open, and a rotary bearing member that extends downward from four corners at the lower end of the box-like body 61 and rotatably supports the rotary shaft 51 of the guide roller 5. 62, a pair of bolts 63 and a pair of nuts 4 that engage with the lower end of the rotary bearing member 62 of the opposing guide roller 5 and a pair of nuts 4 are welded above the box-shaped body 61 to surround the rod 1. It is comprised with the cover member 65. FIG.

The roller surfaces of each of the pair of guide rollers 5 are integrally connected with a plurality of disk-like bodies having different outer diameters so that the centers of the disks coincide with each other so as to be in contact with the outer peripheral surface while surrounding the outer periphery of the rod (casing) 1. It is configured as follows.
With such a configuration, the rod 1 can be hung downward without rotating from the vertical line while rotating.

  Referring again to FIG. 1, an inverted U-shaped hook 21 is attached to the upper end of the attachment 2 for suspending the attachment 2, and a bottoming switch 8 is attached to the center of the upper end of the attachment 2. It has been. The bottoming switch 8 and a control panel 30 described later constitute a determining means.

  A ring-shaped lifting tool 9 is engaged with the hook 21 on the attachment 2 side. The lifting tool 9 is engaged with a hook 12 on the wire block 10 side, and the hook 12 is attached to the tip of a lifting wire (or chain) 11, and the wire (or chain) 11 is wound up by the electric wire block 10. Alternatively, the hook 12 can be raised and lowered by unwinding.

  As shown in FIG. 5, the bottom switch 8 includes a switch main body 81 having a switch function and a movable portion 83 attached to the upper portion of the switch main body via a coil spring 82. And when the said ring-shaped hanging tool 9 comes down and presses the movable part 83, it has a structure which switches on.

  A case is assumed in which, for example, the tip of the rod 1 comes into contact with a hard ground while the rod 1 is being lowered while drilling. If the elevating wire 11 continues to be lowered as it is, the rod 1 whose tip is in contact with the hard ground has stopped descending, so that the suspension 9 and the upper surface of the attachment 2 at the upper end of the rod 1 that has stopped descending are stopped. The upper end of the movable portion 83 of the bottoming switch 8 is close to the positional relationship as shown in FIG. Then, the hanger 9 and the upper end of the movable portion 83 of the bottom switch 8 come into contact with each other, the movable portion 83 is pressed, the spring 82 is bent, and the bottom switch 8 is in an ON (actuated) state (FIG. 6). It becomes.

In FIG. 1, the ON / OFF signal of the bottom switch 8 is sent to the control panel 30 installed on the ground via the signal line Li. If the switch 8 is in the ON state, the control signal line Lo is sent to the electric wire block 10. To stop the operation of the electric wire block 10.
On the other hand, if the hanging tool 9 is separated from the movable portion 83 of the switch 8 (the state shown in FIG. 5), the switch 8 is turned off, and the control panel 30 that has detected the off state sends a control signal to the electric wire block 10, The electric wire block 10 is operated again.

In the construction method, as described above, the high-pressure water jet J is jetted from the tip of the rod 1 in the illustrated direction in the downward direction to drill the ground G. In the drilling, Ground) Muddy water, which is a mixture of G and drilling water, overflows from the drilled hole.
A moat N is dug around the hole H, for example, in an annular shape, and muddy water overflowing from the hole H is collected in the moat N.

  A sand pump 40 is installed in the moat N, and the muddy water sucked up by the sand pump 40 is temporarily stored in the return tank 41 through the drain line Lh, and the muddy water is sucked up from the return tank 41 again. The mud screen 42 separates the solid content and water, and the water portion is temporarily stored in the muddy water tank 43 via the drain line Lh.

  The water temporarily stored and filtered in the muddy water tank 43 is again given high pressure by the high-pressure pump 44, and is pumped as high-pressure water for drilling to the attachment 2 at the rear end of the rod 1 via the high-pressure water supply line Lw. Is done.

  Next, with reference to FIGS. 9-11, the process of drilling by the construction method which concerns on 1st Embodiment is demonstrated in order of a process.

First, in FIG. 9, a high-pressure water jet J is jetted downward from the nozzle of the monitor 1 </ b> M located at the tip of the rod 1. At the same time, while turning the rod 1 by the boring machine 3, the rod 1 is gradually lowered using the electric wire block 10 (see FIG. 1; not shown in FIG. 9) to drill the ground.
The state shown in FIG. 9 assumes that the ground G is a soil having a hardness that is relatively easy to drill, for example, clay, and the distance from the tip of the rod 1 to the bottom of the excavation hole H is a certain interval or more. A gap is maintained.

In FIG. 10, it is assumed that the tip of the rod 1 is in contact with the hard ground portion K. In the state shown in FIG. 10, the tip of the rod 1 can no longer travel by drilling deeper (downward in the vertical direction).
On the other hand, since the lifting / lowering wire 11 continues to descend, the lifting tool 9 is in contact with the movable part 83 of the bottoming switch 8 as shown in FIG. 83 is pressed.
Then, the switch 8 is activated (ON), and the activation signal is transmitted to the control panel 30 (not shown) via the signal line Li (not shown). The control panel 30 to which the operation signal is transmitted sends a control signal to the electric wire block 10 through the control signal line Lo (not shown) to stop the rotation of the electric wire block.
The electric wire block 10 that has received the control signal stops, but the high-pressure water jet J continues to be ejected from the tip of the rod 1 while the electric wire block 10 is stopped. If the state where the high-pressure water jet J is continuously injected and continues to collide with the hard ground K is continued, the hard ground K is also cut and drilled.

If the hard ground K is cut and a gap is formed between the tip of the rod 1 and the bottom of the hole H, the rod 1 starts to descend by its own weight as shown in FIG. The bottom switch 8 is turned off after moving away from (from the state shown in FIG. 5).
The control panel 30 that has detected the OFF state sends a control signal to the electric wire block 10 to operate the electric wire block 10 again. The electric wire block 10 that has received the control signal starts to rotate again, and the rod 1 is moved to a predetermined position. Descent at a speed.

  The drilling of the target hole H is completed by continuing the drilling while repeating the steps described with reference to FIGS.

  According to the first embodiment of the configuration and method as described above, since the high-pressure water jet J is used for drilling, the tip of the rod 1 is always in the air when drilling is normally performed. Since it is in a floating state and only the gravity acts on the casing 1C, it does not receive any force that causes the casing 1C to “shift” from the vertical direction (causes bending). Therefore, excavation can be continued accurately in the vertical direction in which gravity acts.

If the rod 1 moves downward due to its own weight before it is sufficiently drilled by the high-pressure water jet J (when it sinks), the casing 1C leans against the wall surface of the hole H, and drilling accuracy (accuracy with respect to the vertical). ) May be worse. However, as described above, when the front end of the casing 1C is bottomed, the lowering of the casing 1C stops, the drilling speed (or the settling speed of the casing 1C) becomes zero, and the high-pressure water jet is also in the meantime. Continue to inject J downward.
Therefore, the ground below the casing 1C is cut before the casing 1C leans against the wall surface of the hole H, and the direction of the hole is prevented from being “shifted” from the vertical direction.

  In other words, according to the first embodiment described above, the drilling speed of the hole H and the settling speed of the casing 1C can always be balanced to perform accurate drilling in the vertical direction.

At the end of drilling, as shown in FIGS. 3 and 4, the monitor detaching device P is suspended in the casing 1C, and the monitor 1M is pulled up while leaving the casing 1C. Can be built.
Here, it is possible to pull up the monitor 1M by attaching the monitor detaching device P to, for example, the lifting / lowering wire 11, rolling down the wire 11, holding the monitor M <b> 1 by the monitor detaching device P, and winding up the wire 11.

  It should be noted that the monitor unit 1M can be replaced at any time with respect to changes in the ground to be drilled and wear of the nozzle portion at the tip of the rod 1.

  Next, a second embodiment will be described with reference to FIG.

In the first embodiment shown in FIGS. 1 to 11, the high-pressure water jet J injected from a nozzle (not shown) at the tip of the rod 1 is jetted straight in a direction parallel to the central axis of the rod 1. Used.
On the other hand, in the second embodiment of FIG. 12, the rod tip is configured to inject a so-called “cross jet” from the monitor 1M, as shown in detail in FIG. That is, as shown in FIG. 13, a pair of nozzles is provided at the lower end of the monitor 1M, and the pair of high-pressure water jets Jc ejected from the paired nozzles have different ejection directions and have a predetermined distance. S is configured to collide with each other.

  In the second embodiment, by using the “cross jet”, it is possible to control the range in which the soil is cut and drilled or the reach of the water jet with high accuracy.

  Except for the point of whether the water jet for drilling is a straight jet or a cross jet, the configuration and operational effects of the second embodiment are the same as those of the first embodiment.

  Next, a third embodiment will be described with reference to FIGS. 14 and 15.

  14 and FIG. 15 includes a plurality of rods 1B (three in the illustrated example) and driving means 3B responsible for rotational driving thereof.

  In FIG. 14, each of the three rods 1B is guided by the connecting means 5B so that the center does not move.

Each rod 1B is rotationally driven by the drive means 3B.
The driving means 3B is accommodated in the driving means container 300, and a bottom switch 8 is provided at the upper end of the driving means container 300.
Here, since the device shown in FIG. 14 (the hole drilling device used in the third embodiment) is very heavy, it is difficult to move up and down with only a single wire. Therefore, when the drilling device used in the third embodiment is moved up and down, means 302 composed of a plurality of pulleys showing only one part in FIG. 14 is arranged, and the weight is increased by the boosting action of the plurality of pulleys. Up and down drilling equipment.

A pair of brackets 310 are welded to the upper end of the drive means container 300, and a pair of brackets 312 are also welded to the lower end of the means 302.
The brackets 310, 310, 312, 312 are coupled by a connecting rod 314. That is, a long hole 316 is formed in each of the brackets 310 and 310 welded to the upper end of the driving means container 300, and each of the pair of brackets 312 welded to the lower end of the means 302 penetrates each other. A hole 318 is formed. The connecting rod 314 is inserted so as to pass through the long holes 316 and 316 and the through holes 318 and 318, thereby connecting the brackets 310, 310, 312 and 312.

  As in the first and second embodiments, when the tip of the rod 1B comes into contact with the ground, the drive means container 300 stops descending, while the means 302 and the connecting rod 314 descend. continue. As a result, as shown by an arrow B in FIG. 15, the connecting rod 314 descends relative to the bracket 310 and the long hole 316 and comes into contact with the switch 8 at the upper end of the drive means container 300.

  Regarding configurations and operations other than those described above, the third embodiment is substantially the same as the first embodiment or the second embodiment.

Next, FIG. 16 will be described.
FIG. 16 shows a state in which the equipment M below the lifting wire (the lifting cable 110 in the fourth embodiment) in the first embodiment of FIGS. .
The lifting cable 110 is configured to be lifted and lowered by the hoisting machine 120 of the crane C.

With such a configuration, when the drilling area covers a wide range at the construction site, it is only necessary to move the crane C as it is, and the work can be efficiently performed.
The equipment M below the lifting cable 110 is substantially the same as the equipment used in the above-described embodiments.

Instead of the bottom switch 8 shown in FIG. 1, FIG. 5, or FIG. 6, it is also possible to use a bottom switch of the type shown in FIGS.
The member corresponding to the attachment 2 in FIGS. 1, 5, and 6 is the swivel 152 in FIGS. 17 and 18, and the member corresponding to the inverted U-shaped hook in FIGS. It is the yoke-type end 154 in FIG.
17 and 18, a proximity sensor 162 is disposed on the inner end surface 162S of the yoke-type end 154, and this proximity sensor 162 corresponds to the bottoming switch 8 shown in FIG. 1, FIG. 5, or FIG.

  The end type yoke 154 and the swivel 152 are arranged by the rod 160. That is, the end type yoke 154 has through holes 158 and 158, the swivel 152 also has a through hole 160, and the rod 160 is inserted into the through holes 158, 160 and 158. The end type yoke 154 and the swivel 152 are connected.

In particular, as clearly shown in FIG. 18, the inner diameter of the through hole 158 of the end type yoke 154 is larger than the outer diameter of the rod 156 by the dimension indicated by the symbol A.
In addition, as shown in FIG. 17, the distance between the top surface 152S of the swivel 152 and the inner end surface 162S of the end type yoke 154 on which the proximity sensor 162 is provided is indicated by reference sign “A + ΔA”.

In the bottoming switch (proximity sensor 162) shown in FIGS. 17 and 18, when the rod 1 (not shown in FIGS. 17 and 18) is drilled while coming into contact with the hard ground, the lifting wire 11 is used as it is. When the rod 1 (not shown in FIG. 17 and FIG. 18) is continuously lowered, the rod 1 whose tip is in contact with the hard ground stops descending, so that the swivel 152 and the rod 156 are replaced with the end type yoke 154 and the through hole. Relative to 158.
As a result, the distance between the top surface 152S of the swivel 152 and the inner end surface 162S of the end type yoke 154 is smaller than the distance A + ΔA, and the swivel top surface 152S is close to the proximity sensor 162. As a result, the proximity sensor 162 is activated and it is detected that the tip of the rod 1 has reached the bottom.

  Other configurations and operational effects are the same as those of the bottom switch 8 described with reference to FIGS. 1, 5, and 6.

  The illustrated embodiment is merely an example, and is not intended to limit the technical scope of the present invention. For example, the roller surface of the guide roller 5 in the first embodiment shown in FIGS. 1 to 11 may be formed of a smooth curved surface that partially or entirely contacts the outer peripheral surface of the rod 1.

The block diagram which shows the structure of the whole apparatus of embodiment of this invention. The figure which shows the detail of the rod of FIG. The figure which shows the insertion state of the apparatus for pulling up a monitor. The figure which shows the raising state of a monitor. The figure which showed the part enclosed with the circle | round | yen A of FIG. 1 in detail, and is a figure which shows a non-operation state. The figure which showed the part enclosed with the circle | round | yen A of FIG. 1 in detail, and is a figure which shows an operation state. The side view which showed the detailed structure of the casing rotation jig. Y arrow view of FIG. Process drawing which shows the initial stage of the drilling process in 1st Embodiment of this invention. The process figure which shows the state at the time of the drilling process in 1st Embodiment of this invention, when a rod front-end | tip contact | abutted the ground and the bottoming switch act | operated. The process figure which shows a state when the rod tip leaves | separates from the ground and the bottoming switch returns to non-operation in the drilling process in 1st Embodiment of this invention. The block diagram which shows the principal part of the apparatus used by 2nd Embodiment of this invention. The figure which shows the rod front-end | tip part of FIG. The block diagram which shows the principal part of the apparatus used by 3rd Embodiment of this invention. The A arrow partial enlarged view of FIG. The whole block diagram which shows an example of the apparatus used by this invention. The fragmentary sectional view which shows another example of a bottoming switch. The S arrow line view of FIG. The operation state figure explaining the crevice which arises when one of a plurality of excavated excavation holes is inclined and formed. XX sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rod 1C ... Casing 1M ... Monitor 2 ... Attachment 3 ... Boring machine 4 ... Ground surface 5 ... Guide roller 6 ... Guide roller support member 7 ... Casing Rotating jig 8 ... Bottoming switch 9 ... Hanging tool 10 ... Electric wire block 11 ... Lifting wire 12, 21 ... Hook 30 ... Control panel

Claims (3)

A rod (1) having a cylindrical casing (1C) and a nozzle (1M) provided at the lower end of the casing (1C) and having a nozzle for injecting a jet (J) of high-pressure water. ), And the rod (1) rotates in a suspended state and descends at a constant speed to form a vertical drilling hole, the tip of the rod (1) descends at the constant speed Determination means (8, 30) is provided for determining that the hard ground portion (K) that cannot be drilled when contacted, and the rod (1) is lowered at a constant speed, the tip of the hard ground portion ( K) When it is determined by the determination means (8, 30) that it has come into contact with the rod (1), the solid ground portion (K) Drilling the hard ground part (K) When it is determined that the tip of the rod (1) is no longer in contact with the hard ground portion (K) by the determination means (8, 30) after being drilled, the rod (1) is lowered again. Drilling method. The determination means (8, 30) includes a hook (21) attached to an attachment (2) provided at the upper end of the rod (1), and the hook (21) engages with a suspension hook (12) to form a ring. A rod-shaped hanging tool (9) is engaged, and the tip of the rod (1) comes into contact with the hard ground portion (K) on the top of the attachment (2), and the hanging tool (9) is lowered. A control panel (30) for controlling the electric wire block (10) which is provided with a switch (8) to be pressed when it is moved and which receives a signal from the switch (8) and moves the hanging tool (9) up and down. The drilling method according to claim 1, wherein: The drilling method according to claim 1, wherein the jet (J) ejected from the nozzle constitutes a cross jet (Jc).

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