JP6912803B2 - Pile penetration measurement method and pile penetration measurement tool - Google Patents

Description

The present invention relates to a method for measuring a pile penetration amount and the like.

Conventionally, the intrusive amount of piles has been used as a management index for judging the support layer at the time of pile construction. For example, when the amount of penetration (PR value) into the ground per rotation of the pile is equal to or less than the predetermined control value, it is determined that the support layer has been confirmed and the stop is determined.

Patent Document 1 describes a method for detecting the intrusion amount for obtaining the intrusion amount from the relationship between the rotation speed of the rotating pile and the depth of the rotating pile. In this method, the penetration amount is calculated based on the rotation speed of the rotating pile and the depth of the rotating pile in the control device to which the measured value of the detector is transmitted.

Japanese Patent No. 5575589

By the way, in the detection method described in Patent Document 1, the penetration amount is calculated by using a computer, but it cannot be said that the digital data that can be tampered with is highly reliable. Therefore, it may be required to leave the measurement result of the penetration amount in a format other than digital data. In such a case, conventionally, after wrapping the recording paper around a yat corod connected to the stake, the stake is rotated and penetrated while pressing the tip of the writing instrument against the recording paper, and the handwriting for determining the penetration amount is recorded. Leave in. However, in this case, there is a problem that the work of drawing on the recording paper with a writing tool is not easy and the work is difficult when it rains because the pile is not a little shaken when the pile is rotated and penetrated.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a measuring method for measuring the intrusion amount of piles, which facilitates the measurement work of the intrusion amount regardless of the weather.

In order to solve the above-mentioned problems, the first invention is a method for measuring the amount of penetration of a pile that rotates and penetrates into the ground, and when the pile or a rod connected to the pile is used as a winding object, the pile is wound. A preparatory step and a preparatory step of fixing the end of a linear body such as a thread or a string to the outer peripheral surface of the object and holding the linear body extended from the wound object on the side of the pile driving location. Later, a penetration step in which the pile is rotated and penetrated with the linear body stretched, and the linear body unwound from the side of the casting location is wound around the outer peripheral surface of the object to be wound at a substantially constant height. In the penetration step, a measurement step of measuring the axial length of the pile is executed for a predetermined section in which the linear body is wound around the outer peripheral surface of the object to be wound.

In the second invention, in the first invention, a magnet is attached to the end of the linear body, and in the preparation step, the magnet is attached to the outer peripheral surface of the object to be wound to attach the end of the linear body. Fix.

The third invention is a tool for measuring the amount of penetration used in the method for measuring the amount of penetration of a pile according to the first or second invention, which is a reel around which a linear body such as a thread or a string is wound and a linear body. It is equipped with a magnet attached to the end on the unwinding side of the above.

The fourth invention includes, in the third invention, a height adjusting portion which is attached to the same instrument as the reel and has a hole or a groove formed through which a linear body unwound from the reel passes.

In the first invention, the end of the linear body is fixed to the object to be wound and a pile is rotated and penetrated, the linear body is wound around the object to be wound at a substantially constant height, and the linear body is wound. The amount of penetration of the pile is measured by the method of measuring the length of the pile in the axial direction for the predetermined section. Therefore, it is not easily affected by the shake of the pile at the time of rotational penetration, and is also not easily affected by rainfall. Therefore, it is possible to provide a measuring method that facilitates the measurement work of the intrusion amount regardless of the weather.

Further, in each of the second and third inventions, since the magnet is attached to the winding object to fix the end portion of the linear body, it is easy to fix the end portion of the linear body to the winding object. Is.

In the fourth invention, a height adjusting portion having a hole or groove formed through which a linear body unwound from the reel is passed is attached to the same instrument as the reel. Therefore, for an instrument or part (in the fourth invention, the height adjusting portion) for winding the linear body around the outer peripheral surface of the object to be wound at a substantially constant height, an instrument or the like having the same function is used as the ground. It can be made smaller than when it is installed.

(A) Schematic diagram for explaining one step of the preparation step in the method for measuring the intrusion amount of piles, (b) Schematic diagram for explaining another step of the preparation step in the method for measuring the intrusion amount of piles. (A) Schematic diagram for explaining the penetration step in the method for measuring the penetration amount of the pile, (b) Schematic diagram for explaining the measurement step in the method for measuring the penetration amount of the pile. Top view showing the arrangement of tripods, etc. when measuring the penetration amount of piles (A) A diagram for explaining an intrusive amount measuring tool in another embodiment, and (b) a diagram for explaining another intrusive amount measuring tool in another embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 4. The following embodiments are examples of the present invention, and are not intended to limit the scope of the present invention, its applications, or its uses.

[1. Outline of pile construction method]
First, the construction method of the pile (steel pipe pile) 10 will be described. In the construction of the pile 10, one or a plurality of piles 10a and 10b are used depending on the driving length of the pile 10. When using a plurality of piles 10a and 10b, first, the lower pile 10a is rotationally penetrated and buried, and then the joint pile 10b (middle pile or upper pile) is joined to the lower pile 10a by welding or a mechanical joint, and the joint is joined. The pile 10b is rotated and penetrated.

As the lower pile 10a, as shown in FIGS. 1 and 2, a pile having a spiral blade 11 at the tip thereof is used. The piles 10a and 10b are rotationally penetrated (rotary press-fitted) by the pile driver 25 after being built into the pile driver 25. When the piles 10a and 10b are rotated by the pile driver 25, the piles 10a and 10b are press-fitted by the propulsive force generated by the rotation of the spiral blade 11.

In the construction of the steel pipe pile 10, when a predetermined number of piles 10a and 10b are buried, the yat corod 10c shown in FIG. 1A is built, and the yat corod 10c is rotated by the pile driver 25 to rotate the pile 10a. , 10b is further rotated and penetrated. The yat corod 10c is connected to the top pile 10b. Then, when the lower end of the lower pile 10a reaches a depth slightly before the driving completion depth, the driving of the piles 10a and 10b is temporarily stopped and the penetration amount is measured. Details of the measurement of the penetration amount will be described later. Then, when the support layer can be confirmed from the measurement result of the penetration amount, the decision of stopping is made. After determining that the pile 10 is to be stopped, the yat corod 10c is pulled out.

[2. How to measure the amount of pile penetration]
Next, a method of measuring the penetration amount of the pile 10 will be described in detail. In the method for measuring the amount of penetration according to the embodiment, the preparation step, the penetration step, and the measurement step are performed in this order.

In the preparation step, the operator installs the tripod 15 on the side of the driving position of the pile 10 to be measured for the penetration amount, and as shown in FIG. 1A, the reel is attached to the leg head 15a of the tripod 15. 16 (measurement tool for penetration amount) is installed. The reel 16 is fixed on the leg head 15a so as to be horizontally rotatable. Specifically, as shown in the enlarged view surrounded by the wavy line in FIG. 1A, the rod-shaped member 17 is passed through the inside of the tubular portion (body portion) 16a of the reel 16 and is formed through the through hole of the leg head 15a. The reel 16 is installed in a posture in which the rotation axis faces in the vertical direction while passing through the rod-shaped member 17. A water thread 20 is wound around the tubular portion 16a of the reel 16, and a magnet 18 is attached to an end portion (end portion on the unwinding side) of the water thread 20. As the water thread 20, a color (for example, red) that stands out when wound on the outer peripheral surface of the yat corod 10c is used. Further, in order to prevent the reel 16 through which the rod-shaped member 17 is passed from moving from above the leg head 15a, the rod-shaped member 17 may be pressed against the reel 16 by a weight.

Further, in the preparation step, the operator provides a threading member 19 between the place where the pile 10 is driven and the tripod 15 so that the height at which the water thread 20 is wound around the yat corod 10c is constant. In the present embodiment, as the threading member 19, a rod-shaped pile (peg) having a threading portion 19a having a hole at the end is used. Further, the threading portion 19a having a hole is provided so that the entire hole is below the lower end of the tubular portion 16a of the reel 16 or above the upper end of the tubular portion 16a. Instead of the threading member 19, a tripod may be separately installed and the threading portion 19a may be mounted on the tripod.

Then, the operator pulls the water thread 20 laterally from the reel 16 on the leg head 15a, passes the water thread 20 through the threading portion 19a as shown in FIG. 1 (b), and then passes the water thread 20. A magnet 18 is attached to the outer peripheral surface of the 10c to fix the end portion of the water thread 20. The operator keeps the water thread 20 stretched substantially horizontally between the threading portion 19a and the attachment portion of the magnet 18. That is, on the outer peripheral surface of the yat corod 10c, the magnet 18 is fixed at substantially the same height as the hole of the threading portion 19a. Then, the penetration step is performed in this state.

In the penetration step, as shown in FIG. 2A, the pile driver 25 rotates the yat corod 10c to restart the driving of the pile 10. During the rotation of the Yatco rod 10c, tension is applied to the water thread 20. Then, the water thread 20 is unwound from the reel 16, and the water thread 20 is wound around the outer peripheral surface of the yat corod 10c. Since the water thread 20 is passed through the threading portion 19a and the yat corod 10c side is substantially horizontal, the height at which the water thread 20 is unwound from the reel 16 changes, but the water thread 20 is the outer circumference of the yat corod 10c. The height around the surface is almost constant. When the yat corod 10c is rotationally penetrated, the water thread 20 spirally winds around the yat corod 10c.

Further, after the pile 10 is restarted, one worker looks into the level surveying instrument (not shown) and keeps visually observing the penetration amount of the pile 10 after the pile 10 is restarted. At the timing when the penetration amount after resumption becomes, for example, 20 cm, the operator of the pile driver 25 is notified of "the end of driving" and the rotation of the yat corod 10c by the pile driver 25 is stopped.

Note that FIG. 3 is a plan view showing the arrangement of the tripod 15 and the like when measuring the penetration amount of the pile. 1 and 2 show the pile driver 25, the yat corod 10c and the tripod 15 from the left side for convenience so that the tripod 15 and the yat corod 10c do not overlap with each other. As shown in the above, a tripod 15 is installed on the driver's seat 25a side of the pile driver 25. In this way, the level surveyor and its workers are placed in front of or to the left of the driver's seat 25a where the operator of the pile driver 25 is located, and the operator of the pile driver 25 is asked to "end the driving". This is to make it easier to convey the signal. The plane arrangement at the time of measuring the penetration amount of the pile is not limited to the arrangement shown in FIG.

Next, a measurement step is performed. As shown in FIG. 2B, the operator 30 uses a length measuring tool 21 for measuring the length of a convex (tape measure), a ruler, etc., to wind the water thread 20 around the outer peripheral surface of the yat corod 10c. The measurement length L in the axial direction of the yat corod 10c is measured for the last one turn (predetermined section) of all the sections. This measurement situation is photographed by another worker.

Here, the measurement length L measured by using the length measuring tool 21 is equal to the penetration length of the pile 10 which has been rotationally penetrated in the last rotation immediately before the end of driving. Therefore, by measuring the axial length of the last roll, the measurement result of the penetration amount (PR value) per rotation can be obtained. When the operator can confirm the validity of the PR value measurement result by comparing the PR value measurement result with the digital measurement value of the penetration amount in the pile driver 25 (the measurement value of the last rotation), the support layer Is judged to have been confirmed.

[3. Effects of embodiments, etc.]
In the present embodiment, the end of the water thread 20 is fixed to the yat corod 10c, the pile 10 is rotationally penetrated, the water thread 20 is wound around the yat corod 10c at a substantially constant height, and the water thread 20 is wound around the yat corod 10c. The penetration amount of the pile 10 is measured by a method of measuring the axial length of the pile 10 for the section. Therefore, it is not easily affected by the shaking of the pile 10 at the time of rotational penetration, and is also not easily affected by rainfall. Therefore, it is possible to provide a measuring method that facilitates the measurement work of the intrusion amount regardless of the weather. Further, when measuring the penetration amount, the pile may be rotated in the reverse direction because the ground is hard, but even in such a situation, the measurement work can be easily repeated.

Further, since the magnet 18 is attached to the yat corod 10c to fix the end portion of the water thread 20, the work of fixing the end portion of the water thread 20 to the yat corod 10c is easy.

[4. Other embodiments]
In the above-described embodiment, the reel 16 is not indispensable, and the operator holds the water thread 20 extending from the affixed portion on the outer peripheral surface of the yat corod 10c at a constant height during the rotational penetration of the yat corod 10c and tensions it. You may pay out the water thread 20 while applying. Further, the operator may hold the water thread 20 extending from the attachment portion on the outer peripheral surface of the yat corod 10c through the threading portion 19a.

Further, in the above-described embodiment, the water thread is used as the linear body 20, but the present invention is not limited to this, and other objects such as a string and a rope may be used.

Further, in the above-described embodiment, the water thread 20 is attached to the outer peripheral surface of the yat corod 10c by the magnet 18, but the water thread 20 may be attached by other means such as tape.

Further, in the above-described embodiment, the example in which the method for measuring the intrusion amount of the present invention is applied to a straight pile has been described, but the method for measuring the intrusion amount of the present invention may be applied to an oblique pile.

Further, in the above-described embodiment, the threading member 19 is provided on the ground, but as shown in FIG. 4, the water thread 20 unwound from the reel 16 is used as a component to be attached to the same instrument as the reel 16. A height adjusting portion 23 having a hole or groove for passing through may be provided in the penetration amount measuring tool 35. In FIG. 4A, the height adjusting portion 23 is fixed to the leg head 15a of the tripod 15 that does not rotate together with the reel 16. The height adjusting portion 23 is provided with a threading portion 23a having a hole. The water thread 20 unwound from the reel 16 is passed through a hole in the threading portion 23a. Further, in FIG. 4B, the rod-shaped member 17 is fixed to the leg head 15a, and the height adjusting portion 23 is fixed to the rod-shaped member 17. The height adjusting portion 23 is attached to the tripod 15 via a rod-shaped member 17. The height adjusting portion 23 is provided with a threading portion 23a having a groove. The water thread 20 unwound from the reel 16 is passed through a groove (a groove whose upper side is open) of the threading portion 23a.

Further, in the above-described embodiment, the axial length of the pile 10 is measured for the last one of the sections in which the thread 20 is wound around the outer peripheral surface of the yat corod 10c in the penetration step, but the pile 10 is wound a plurality of times. The length of the pile 10 in the axial direction may be measured for the section, and the measurement length may be divided by the number of windings to calculate the measurement result of the PR value.

The present invention can be applied to a method for measuring the amount of penetration of piles and the like.

10 Pile 10a Lower pile 10b Joint pile 10c Yatco rod (rod)
15 Tripod 16 Reel (Measuring tool for penetration amount)
18 Magnet 19 Threading member 20 Water thread (striatum)
21 Length measuring tool 25 Pile driver

Claims (4)

It is a method of measuring the amount of penetration of piles that rotate and penetrate into the ground.
When the pile or a rod connected to the pile is used as a winding object, the end of a linear body such as a thread or a string is fixed to the outer peripheral surface of the winding object, and the pile is placed at a place where the pile is placed. A preparatory step for holding the linear body extended from the winding object on the side of the
After the preparatory step, the pile is rotationally penetrated in a state where the linear body is stretched, and the linear body drawn out from the side of the driving portion is drawn out from the side of the driving portion at a substantially constant height to be the outer periphery of the winding object. The penetration step to wrap it around the surface and
In the penetration step, the penetration amount is characterized by executing a measurement step of measuring the axial length of the pile in a predetermined section in which the linear body is wound around the outer peripheral surface of the winding object. Measurement method. A magnet is attached to the end of the linear body,
The method for measuring the penetration amount according to claim 1, wherein in the preparation step, the magnet is attached to the outer peripheral surface of the winding object to fix the end portion of the linear body. A tool for measuring the amount of penetration used in the method for measuring the amount of penetration of a pile according to claim 1 or 2.
A reel around which a linear body such as a thread or string is wound,
A tool for measuring the amount of penetration, which comprises a magnet attached to an end portion of the linear body on the unwinding side. The penetration according to claim 3, wherein the penetration is attached to the same device as the reel and includes a height adjusting portion formed with a hole or a groove through which a linear body unwound from the reel passes. A quantity measuring tool.

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