JPH10288522A - Displacement amount detecting method of auger excavated hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a displacement amount detecting method of an auger excavated hole, capable of making improvements in excavating accuracy by grasping an amount of displacement to an ideal vertical hole of the auger excavation at a real time during operations, and correcting the excavating direction and the like. SOLUTION: An inclinometer 20 capable of measuring a tilt angle to the vertical direction is installed in a tip auger rod 11, and in a first measuring point P1 where this tip rod 11 exists underground, an amount of displacement T1 =L1 sinθ1 is grasped from a tilt angle θ1 and tip rod length L1 by the inclinometer 20, and in a second measuring point P2 where the tip rod 11 + a second rod 12 exist underground, and amount of horizontal displacement T2 =L2 sinθ2 to the first measuring point P1 is grasped from a tilt angle θ2 and another rod length (second rod length) L2 entered underground anew, and then an equation T1 +T2 =L1 sinθ1 +L2 sinθ2 is grasped as the displacement at the second measuring point P2 . Likewise, the amount of displacement T in the current depth is additively calculable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting the amount of displacement of an auger excavation hole, and more particularly to how much the tip of a hole being excavated by a uniaxial auger is displaced from an ideal vertical hole in a horizontal plane. Etc. during excavation work.

[0002]

2. Description of the Related Art Although a single-axis auger excavates the ground vertically downward from the starting point of excavation on the ground, the excavation hole is inevitably slightly displaced with respect to an ideal vertical hole passing through the excavation starting point,
It is known that this displacement increases as the excavation depth increases. The auger is also known to bend slightly in the ground from the seam between each auger rod that is added as the excavation progresses, so that the shape of the excavation hole is slightly concentric rather than concentric cylindrical. . Therefore, when constructing a foundation pile or the like at a large depth, when the displacement amount or the bending exceeds a permissible range in the uniaxial auger, a problem occurs that the pile cannot cope with a predetermined stress. Also, when constructing a water impervious wall with a soil cement wall in the basement, in order to increase the construction accuracy of the soil cement wall on large depth walls,
It is common practice to first drill a hole with a single-axis auger and then build a soil cement wall using this hole as a guide.In this case, the drilling accuracy of the single-axis auger is important. If the amount of displacement or bend exceeds the allowable range, the soil cement walls cannot be accurately adjacent to each other, and there is a problem that the water cannot be blocked.

At present, the conventional measurement of the excavation accuracy of a single-axis auger is carried out by inserting a leak-type inclinometer at the center of the auger at the end of excavation, which takes time and effort. The auger is left in the ground during the measurement, so if the ground is bad, the auger may not come out of the ground after the measurement, and this is a measurement after drilling, so it is impossible to correct it. If the amount is out of tolerance,
It had to go through the process of backfilling, digging again, and measuring again.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to grasp, for example, the amount of displacement of an auger drilling hole in real time during the drilling operation. Measures such as correcting the direction of auger excavation at the beginning of turning to improve the auger excavation accuracy and thereby provide an auger excavation hole displacement detection method that enables the auger to build a large depth continuous wall Is to do.

[0005]

According to the present invention, there is provided a method of detecting a displacement of an auger drilling hole according to the present invention, which comprises detecting a displacement of a hole being drilled with respect to an ideal vertical hole by a single-axis auger. A tilt angle measuring means capable of measuring a tilt angle with respect to the vertical direction is provided in the auger rod at the tip, and the displacement amount is calculated from the tilt angle measured by the tilt angle measuring means.

The ideal vertical hole is an ideal virtual hole having a vertical axis passing through the excavation starting point (center of the surface opening) of the actual excavation hole as a hole axis, and the displacement amount of the excavation hole is the same horizontal plane. Is detected as the distance between the tip of the auger and the vertical axis. That is, based on the inclination angle θ obtained by the inclination angle measuring means provided inside the tip auger rod and the underground auger length L, the displacement amount T of the auger tip part is calculated as T = L sin
The inclination direction in the horizontal plane is defined in advance by defining the X-Y plane and the X-axis and the Y-axis inside the auger with the center (vertical axis) of the ground surface opening as the origin. , Y axis can be determined by measuring the tilt angle at the auger rotation position where the X axis and the Y axis coincide with the XY plane.

As the inclination angle measuring means, a known inclinometer, a gyro or the like can be used, and it is desirable to install this at the end of the auger rod core.

[0008] As described in the prior art, it is known that the underground auger is slightly bent from the joint of the auger rod. Therefore, in the present invention, the measurement of the inclination angle by the inclination angle measuring means is performed by each auger rod. It can be performed for each long excavation depth. That is, the extension line of the axis of the tip auger rod may significantly deviate from the origin on the ground surface. In this case, the inclination angle obtained by the inclination angle measuring means provided on the tip rod indicates the inclination of the tip rod. However, this cannot represent the inclination of the entire auger. Therefore, the measurement point of the inclination angle is determined by the length of each auger rod (L ₁ , L ₂ ,
L ₃ · · ·) worth of sets for each excavation depth, in the first measurement point that only the tip rod is in the ground, the inclination angle theta ₁ and the tip rod length displacement T ₁ in the measurement point from L ₁ = L ₁
Sin θ ₁ is grasped, and at the second measuring point where the tip rod and the second rod are underground, the inclination angle θ ₂ and the rod length (the second rod length) L ₂ that has newly entered the ground are first determined. First
The horizontal displacement amount T ₂ = L ₂ sin θ ₂ with respect to the measurement point can be grasped, and T ₁ + T ₂ = L ₁ sin θ ₁ + L ₂ sin θ ₂ can be grasped as the displacement amount at the second measurement point, and so on. Then, the displacement amount at the current depth can be calculated additively.

At the second measurement point, the inclination angle θ _{1 at} the first measurement point has already slightly changed, and therefore, the displacement L ₁ sin θ ₁ + L ₂ sin θ _{2 at} the second measurement point.
Has an error, and this error may accumulate in a measurement value at a subsequent measurement point. In order to eliminate such adverse effects, according to the present invention, the inclination angle measuring means can be provided in each auger rod. In this way, the inclination angle at each measurement point can be measured at the same time, and therefore, it is possible to avoid the above-described accumulation of errors when the displacement amount at the current measurement point is grasped based on the measurement result of the front side point. In addition, there is no need to set a measuring point in rod length depth units.

[0010]

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

FIG. 1 is an explanatory view showing a single-axis auger 10 for convenience such as omitting a screw portion.
Numeral 0 indicates that the ground is excavated while being rotated and driven by the auger driving device 15, and the auger rods are added together with the excavation. In FIG.
_1, L _2, L _3, first to fourth rod L is ₄ 11,1
2, 13, and 14 are connected. Each rod is manufactured as a double tube, and a communication cable and a rod-to-rod transmitter / receiver for taking in the inclination angle measuring means and the measurement result into a computer of a base machine (not shown) via an electrode extraction slip ring 16 at the auger base in the inner tube. And so on. On the other hand, outside the inner tube in the auger, a hardening liquid such as cement milk or a water supply passage is provided as in the conventional case.

An inclinometer (CA-940-0505) 20 manufactured by Macome Laboratories as an inclination angle measuring means is provided at the tip of the innermost tube of the auger rod 11 together with a battery, a control board (not shown) and the like. Will be installed. The inclinometer 20 includes a pendulum with a magnet and an XY magnetic sensor (not shown), and can measure a slight tilt of the pendulum with respect to the vertical direction as tilt angles in the X-axis direction and the Y-axis direction which are defined and set in advance. Things.

Prior to excavation, ground surface GL (see FIG. 2)
The center of the planned borehole (and the vertical axis A passing through this center)
Is defined as the origin O, and the X axis and the Y axis corresponding to the XY magnetic sensor of the inclinometer 20 are also set for the auger 10 so that the X axis and the Y axis in the auger are Auger 1 coinciding with the X-axis and Y-axis of the XY plane
The measurement of the tilt angle is performed at the zero rotation position. The rotation position of the auger 10 is managed and detected by a rotation position detector 17 at the base of the auger, and the length of the underground auger is managed and detected by a depth gauge 18.

Next, the use state of the present invention will be described.
FIG. 2 schematically shows a vertical axis A passing through the origin point O, that is, an axis of an ideal vertical hole, and an excavation hole (axis) A ′ in the middle of excavation that has been excavated to the first to fourth rods 11, 12, 13, and 14. , The displacement of the excavation hole A ′ with respect to the vertical axis A is exaggerated for convenience.

When the first rod (rod length L ₁ ) 11 enters the ground, the first measurement of the inclination angle θ ₁ is performed (actually, the inclination angles in the X-axis direction and the Y-axis direction are measured). that.), the displacement amount T ₁ in auger 10 tip or first measurement point P ₁ at this point T ₁ = L ₁
sin θ ₁ . Next, the second rod (rod length L ₂ ) 1
When the second measurement point 2 further enters the ground, the second measurement of the inclination angle θ ₂ is performed, and the horizontal displacement (section displacement) T ₂ = L of the _second measurement point P ₂ with respect to the first measurement point P ₁ . Calculate ₂ sin θ ₂ .
Therefore, the displacement amount with respect to the vertical axis A at the measurement point P ₂ becomes _{T 1 + T 2 = L 1} sinθ 1 + L 2 sinθ 2. The same applies to the third measurement point P _3, the displacement amount T in the fourth measurement point P ₄ is the current time is shown, T = T ₁ + T ₂
+ T ₃ + T ₄ = L ₁ sin θ ₁ + L ₂ sin θ ₂ + L ₃ sin
θ ₃ + L ₄ sin θ ₄ , and the same applies to the measurement work after the measurement point P ₄ .

As described above, since the inclination angle of each measurement point by the goniometer 20 is detected as the inclination angle in the X-axis direction and the Y-axis direction, the horizontal displacement between each measurement point is also in the X-axis direction. And the value in the Y-axis direction. Thus, for example, the fourth measurement point displacement of the X-axis direction in the P ₄ (the accumulation of the horizontal displacement of the X-axis direction between the measuring points) x, the displacement amount in the Y-axis direction (Y-axis between the respective measurement points Assuming that the horizontal displacement in the direction (accumulation of the horizontal displacement) is y, the displacement T can be obtained by the square root of x ² + y ² , and this state appears on the output display screen of the computer as shown in FIG.

A single-axis auger 40 shown in FIG. 4 has an angle meter 5 similar to that described above on each auger rod 41, 42, 43, 44.
1, 52, 53 and 54 are provided. In the above-mentioned auger 10, since the displacement amount at the present time is grasped based on the measurement result at the previous measurement point, there is a possibility that measurement errors may be accumulated. That is, taking the second measurement point as an example, at the time when the tip of the auger reaches the measurement point, the inclination angle θ _{1 at} the first measurement point has already slightly changed to θ ₁ ′. The displacement amount at the measurement point 2 is exactly L ₁ sin θ ₁ ′ + L ₂ sin θ ₂ . on the other hand,
In the auger 40, the inclination angle at each measurement point can always be simultaneously grasped as a value at the present time, so that the accumulation of the error can be removed, and the excavation accuracy can be further improved. Therefore, it is not necessary to set the measuring points in rod length units. For example, the measuring points can be set only when the rods 41, 42, 43, and 44 enter the ground.

[0018]

As described above, in the method for measuring the displacement of an auger excavation hole according to the present invention, the displacement of the tip of the auger relative to the ideal vertical hole is determined by the inclination angle measuring means provided in the auger rod. To detect the shape of the borehole at the current point in time,
For example, it is possible to improve the auger excavation accuracy by appropriately modifying the auger excavation direction etc. at the beginning of the hole bending, so that it is possible to construct a large depth continuous wall using a single axis auger, which was difficult conventionally. can do.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a single-axis auger provided with a goniometer at a tip end.

FIG. 2 is an explanatory diagram showing an implementation state of the method for convenience showing an axis of an ideal vertical hole and an axis of a borehole.

FIG. 3 is a plan view showing a screen in which a displacement of an actual excavation hole with respect to an ideal vertical hole at a fourth measurement point is displayed on a CRT.

FIG. 4 is an explanatory view showing a single-axis auger in which a goniometer is provided on each auger rod.

[Explanation of symbols]

10, 40 Single-axis auger 11, 12, 13, 14, 41, 42, 43, 44 Auger rod 20, 51, 52, 53, 54 Angle meter 15 Auger drive 16, 46 Electrode take-out slip ring 17 Rotational position detection axis P ₁ of the machine 18 depth gauge O origin a vertical axis a _{'borehole, P 2, P 3, P} 4 survey point _{θ 1, θ 2, θ 3} , θ 4 inclination angle _{L 1, L 2, L 3} , L ₄ rod length T displacement amount T ₁ of the present _{time, T 2, T 3, T} 4 sections displacement

Claims (3)

[Claims] 1. A method for detecting a displacement amount of a hole being excavated with respect to an ideal vertical hole by a single-axis auger, wherein an inclination angle with respect to a vertical direction can be measured in at least a tip of an auger rod of the auger. Providing means,
A displacement amount detection method for an auger excavation hole, wherein the displacement amount is calculated from the inclination angle measured by the inclination angle measuring means. 2. The displacement detection method for an auger excavation hole according to claim 1, wherein the inclination angle is measured by the inclination angle measuring means at each excavation depth corresponding to each auger rod length. 3. The method according to claim 1, wherein the inclination angle measuring means is provided in each auger rod.