JP2015101920A - Prediction method of anchor pull-out strength and anchor driving method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently predict the pull-out strength of anchors to be driven accompanied by the driving work of the anchors at each anchor, to decide the arrangement of the anchors on the basis of the prediction, and to surely lock, for example, a weed-proof sheet on the soil.SOLUTION: A prediction method of anchor pull-out strength includes: a step S104 for driving anchors by using an electric drill; a step S105 for measuring a current value which is consumed by the electric drill during the driving work of the anchors while making the value correspond to a time necessary for the driving work; and a step S106 for comparing at least either of a time necessary for the finish of the driving after a start of the driving of the anchors, and a cumulative value of the measured current value with a preset reference value, and predicting the pull-out strength of the anchors which are driven into driving positions. The pull-out strength of the anchors is predicted on the basis of the current value and the time necessary for the driving, the anchors are driven at intervals based on the prediction, and a weed-proof sheet is locked to the soil.

Description

  The present invention relates to a method for predicting the pullout strength of an anchor driven in, for example, the pullout strength of an anchor driven into the soil from above the grassproof sheet in order to lock the weedproof sheet covering the surface of the soil to the soil, and The present invention relates to an anchor driving method.

In civil engineering and construction, construction to drive anchors is common.
As such construction, there is, for example, fixing by an anchor of a weedproof sheet.
Specifically, if the soil is exposed and there is no traffic of people or vehicles, such as an idle land under a bridge or an unpaved shoulder, if we leave it in a small place, weeds will grow, Becomes vulnerable and the prospects worsen, causing maintenance and security problems.
For this reason, various weed countermeasures have been proposed for such soil surfaces.
One of the measures against weeds is the construction of covering the soil surface with a weedproof sheet.

In this case, as disclosed in Japanese Patent Laid-Open No. 6-248652, an anchor is driven toward the soil from above the weedproof sheet covering the surface of the soil, and the weedproof sheet is locked to the surface of the soil.
Such anchors are typically driven into the soil using a power drill, such as a vibrating drill.

  Thus, when the weedproof sheet is locked to the surface of the soil via the anchor, the locked state of the weedproof sheet is the degree of force required when the anchor is pulled out from the soil, that is, the soil of the anchor. Depends on the pullout strength against.

On the other hand, the nature of the soil into which the anchor is driven varies, and even in the same area, the strength of the ground is uneven.
For this reason, when anchors are driven at equal intervals, the locking strength of the herbicidal sheet with respect to the soil decreases in places where the anchor pulling strength is weak, and the sward or strong wind causes the weeding sheet to roll up from the soil surface, There is a risk of peeling.

In order to prevent such turning and the like, it is necessary to narrow the interval at which the anchor is driven or to increase the driving density.
However, if the distance between all anchors is narrowed in order to prevent peeling of the herbicidal sheet, unnecessary anchors are driven in places where the pullout strength of the anchors is high, resulting in a problem that construction costs increase.

In order to cope with this problem, it is only necessary to narrow the interval at which the anchors are driven or increase the density at which the anchors are driven, in a place where the anchor pull-out strength is low.
However, conventionally, the anchor pull-out strength is often determined based on the experience and intuition of the worker, and the construction result, that is, the quality, varies depending on the skill level of the worker, and an unnecessarily large amount. There was a problem that the anchor was driven in or the locking strength of the grass protection sheet was insufficient.

  In addition, using various measuring machines and measuring the properties and strength of the soil in advance for each anchor placement location can suppress variations in quality due to the ability of the workers. It is not realistic to perform various measurement operations in parallel because the construction burden is very large and the construction period is greatly extended.

  In the past, when the anchor was driven, it was impossible to predict the pullout strength of the anchor that was driven without lowering the work efficiency. Therefore, the anchor was passed at an appropriate density according to the situation of the anchor driving position. It was not possible to lock the surface of the soil on the surface of the soil at a low cost, simply and reliably with a certain quality.

JP-A-6-248652

The present invention has been made in order to solve the above-mentioned problem, and it is possible to efficiently predict the pullout strength of the anchor to be driven for each anchor in accordance with the operation of driving the anchor. The purpose is to determine the placement of anchors to be driven according to the strength and properties of the target to which the anchors are driven, and to ensure stable construction quality.
Further, according to the present invention, when the herbicidal sheet is locked to the surface of the soil by the anchor, the pattern of driving the anchor is determined according to the predicted pullout strength, so that the herbicidal sheet is engaged with the surface of the soil. The purpose is to keep the stopping strength above a certain level, to maximize the effect of the weedproof sheet, to ensure that the weedproof sheet can be locked to the soil, and to reduce the burden of maintenance work after construction.

To achieve the above object, the anchor pullout strength predicting method according to the first aspect of the present invention comprises:
A method for predicting the pull-out strength of an anchor driven into soil in order to lock the herbicidal sheet to the surface of the soil,
Using an electric drill to drive the anchor into the soil;
A step of measuring the current value consumed by the electric drill during the driving operation of the anchor in correspondence with the time required for driving;
Comparing at least one of the time required from the start of driving the anchor to the end of driving and the accumulated value of the measured current value with a predetermined reference value, the pullout strength of the anchor driven into the driving position is predicted. And a step.

Moreover, the prediction method of the pullout strength with respect to the soil of the anchor which concerns on 2nd invention in 1st invention,
The step of predicting the pulling strength is
The peak value of the current at the end when the driving of the electric drill motor stops by the end of anchor driving,
A high load cumulative value that is a cumulative value of a current value that is equal to or greater than a predetermined current value, excluding the time when motor driving is started, among the measured current values during anchor driving,
The total cumulative value that is the cumulative value of the current value measured from the start of driving the motor of the electric drill by the start of anchor driving until the end of the driving,
And obtaining a high load maintenance time indicating a time during which a current value equal to or greater than the predetermined current value is measured, and predicting a pull-out strength.

によって特定されることを特徴とする。
なお、前記式（１）において、Ａはピーク値、Ｂは高負荷累積値、Ｃは全体累積値、Ｓは高負荷維持時間とする。 Moreover, the prediction method of the pulling-out strength with respect to the soil of the anchor which concerns on 3rd invention in 2nd invention,
The predicted value N of the pullout strength is the following formula (1)

It is specified by.
In the formula (1), A is a peak value, B is a high load accumulated value, C is an overall accumulated value, and S is a high load maintaining time.

Moreover, the prediction method of the pullout strength with respect to soil of the anchor according to the fourth invention is the second or third invention,
The predetermined current value is 3.0 A.

In order to achieve the above object, the anchor driving method according to the fifth aspect of the present invention includes:
When the pullout strength predicted by the method for predicting the pullout strength of the anchor according to any one of the first invention to the fourth invention is equal to or less than a predetermined pullout strength, an interval between anchors driven around the anchorage is determined. It is characterized in that it is narrower than the interval between the anchors driven around the anchors exceeding the predetermined pulling strength, and the anchor driving density is changed according to the predicted pulling strength.

  In the first to fourth inventions described above, by measuring the current value of the electric power consumed by the electric drill used for the anchor driving operation in correspondence with the passage of time, the driving operation is performed simultaneously with the anchor driving operation. Without carrying out any other work, the pullout strength of the anchor to be driven in can be predicted, and the state of the soil can be easily and reliably grasped at a low cost without any time loss.

  Further, in the fifth invention, with reference to the predicted pullout strength, the anchor can be driven without excess or deficiency corresponding to the state of the soil, so that the herbicidal sheet can be easily and reliably fixed with a certain quality. Can be locked to the soil surface at low cost.

FIG. 1 is an explanatory diagram showing the configuration of an embodiment of a system used in the anchor pullout strength prediction method according to the present invention. FIG. 2 is a partial cross-sectional view showing a locked state of the weedproof sheet by the anchor driven by the system of FIG. FIG. 3 is a flowchart for explaining the process from anchor driving to prediction processing by the system of FIG. FIG. 4 is a flowchart for explaining the process of predicting the pulling strength by the system of FIG. FIG. 5 is a graph showing changes in current values obtained at three points with different pullout strengths by the system of FIG. FIG. 6 is an explanatory diagram showing arrangement items for generating analysis data in the graph of FIG.

In the present invention, when an anchor is driven into the soil, for example, when the anchor is driven into the soil, the current value consumed by the electric drill is used to pull out the anchor from the soil into which the anchor is driven. The strength is predicted, and the density and interval at which the anchor is driven are adjusted based on the prediction, so that the herbicidal sheet can be reliably locked to the soil surface by the anchor.
Hereinafter, based on an Example, this invention is demonstrated in detail.

  FIG. 1 is an explanatory view showing a configuration of an embodiment of a system used in a method for predicting the pullout strength of an anchor according to the present invention, and FIG. 2 shows a locking state of a weedproof sheet by an anchor driven by the system of FIG. It is a fragmentary sectional view shown.

First, an anchor driving system used in the anchor pullout strength prediction method according to the present invention will be described with reference to FIGS. 1 and 2.
In the figure, 1 is a driving system, 10 is an electric drill, 11 is a prediction processing device, 110 is a monitor, 111 is an operation panel, 2 is an anchor, 3 is a washer, 4 is a weed protection sheet, and 5 is soil.

In the driving system 1, an external prediction processing device 11 is attached to an electric drill 10.
The electric drill 10 is a general-purpose electric drill similar to a normal electric drill or a vibration drill, for example, and has at least an output terminal that can output a current value consumed in a driving operation. It is a thing.
For this reason, description about the structure and function of a general-purpose electric drill is omitted.

The prediction processing device 11 is provided with locking means (not shown), and is directly attached to the main body of the electric drill 10 via the locking means.
Moreover, the prediction processing apparatus 11 includes a monitor 110 and an operation panel 111, and further includes an input line (not shown) connected to the output terminal of the electric drill.
The monitor 110 displays a control screen necessary for operating the prediction processing device 11 and various screens corresponding to the operation.

The operation panel 111 is an input panel provided with various switches for operating the prediction processing device 11.
The details of the operation of the prediction processing device 11 will be described later, but the anchor that has been driven into the driving position based on the current value input from the input line in accordance with the setting information input from the operation panel 111 and various command information. The pullout strength is predicted, and the prediction result is displayed on the monitor 110.

Based on this display, the user of the electric drill 10 drives the anchor again in the vicinity of the anchor that has been determined to have low pullout strength.
The anchor 2 is an inverted L-shaped member that is driven into the soil 5 from the lower end.
The washer 3 is an annular member made of, for example, resin, and is disposed on a weedproof sheet 4 disposed so as to cover the surface of the soil 5 when the anchor 2 is driven. Penetrates.

The washer 3 prevents the upper end of the anchor 2 from directly biting into the weedproof sheet 4 and damaging the weedproof sheet 4.
The weedproof sheet 4 is for preventing weeds from growing on the soil 5, and is a general-purpose sheet that has already been put into practical use.
The soil 5 is a construction target that needs to prevent weeds from growing or thickening.

Next, a method of driving the anchor 2 into the soil 5 using the driving system 1 will be described with reference to FIG.
FIG. 3 is a flowchart for explaining the process from anchor placement to display of a prediction result by the system of FIG.
First, the prediction processing device 11 is attached to the electric drill 10, the input line is connected to the prediction processing device 11 to the output terminal of the electric drill 10, and the current value can be input to the prediction processing device 11. 11 is mounted on the electric drill 10 (S101).

Next, the operation panel 111 of the prediction processing apparatus 11 is operated, and the setting information including the condition of the soil 5, for example, the ground type, is input (S102).
In order to prevent the prediction result from being uniformly biased according to the extreme strength and vulnerability of the ground 5, this setting information is preferably performed before the construction of a series of operations. The normal mode for construction with respect to construction may be set as default, and input may be made only when construction is performed on a specific ground.
(* Regarding the setting of ground information, it is better to explain the influence of the ground information setting on the prediction process more concretely. For example, in the case of ground where the average strength seems to be higher than the standard range Please give a specific explanation such as increasing the preset current value, which will be described later, and decreasing the current value if it is low.)

Next, the anchor 2 is mounted on the drill chuck of the electric drill 10 as shown in FIG. 1 (S103).
Next, the washer 3 is placed on the grass protection sheet 4 laid on the surface of the soil 5, the tip of the anchor 2 is pressed against the center hole of the washer 3, the electric drill 10 is operated, and the anchor 2 is moved to the soil 5. (S104).
As a result of this driving operation, the weedproof sheet 4 is fixed to the surface of the soil 5 by the anchor 2 via the washer 3 as shown in FIG.

Next, prediction processing by the prediction processing device 11 will be described.
The following processing operations are executed in accordance with a predetermined program by a control means (not shown) provided in the prediction processing device 11, and the prediction processing device 11 is operated by the input current value and prediction processing. It has a storage means (not shown) for recording various information such as obtained results.

As already described, the prediction processing device 11 receives an input of a current value consumed by the electric drill 10.
This current value is measured corresponding to the time required for driving and recorded in the prediction processing apparatus 11 (S105).
For this reason, the current value is measured from the start to the end of anchor driving.

The measured current value is stored in a storage means (not shown) corresponding to the driving work time.
When the anchoring operation of the anchor 2 is completed, the following values are calculated based on the information stored in the storage means, the information is read out, and the extraction strength is predicted (S106). .

Note that at least a part of the above calculation or the like may be directly acquired from input information from the electric drill 10 simultaneously with the driving operation, and in this case, the processing time can be shortened.
Next, based on FIG. 4, the prediction process shown in FIG. 3 is demonstrated concretely.
When the prediction process is started, the peak value of the current at the time when the driving of the motor of the electric drill 10 stops is read out.
Further, during the driving of the anchor 2, among the current values measured and stored, the accumulated value of current values equal to or higher than a predetermined current value among the current values excluding when the motor starts driving is calculated. Acquired as the accumulated load value.
In the present embodiment, the predetermined current value is, for example, 3.0A.

The current value is changed depending on the type, size, output, etc. of the electric drill, and when the prediction processing device 11 is mounted on the electric drill 10, an input is set via the operation panel 11. In addition, when the prediction processing device 11 is connected to the electric drill 10, the setting signal may be received from the electric drill 10, and the prediction processing device 11 is, for example, specified. When a dedicated product corresponding to the electric drill 10 is used, or when the prediction processing apparatus is integrated with the electric drill 10, a preset value that does not require setting may be used.
Further, the total accumulated value obtained by accumulating the current values measured from the start of driving of the motor of the electric drill 10 by the start of driving of the anchor 2 until the end of the driving is acquired.
Further, a cumulative value of a current value of 3.0 A or more which is the above-described predetermined current value, that is, a high load maintenance time indicating a time when the high load cumulative value is measured is acquired (S201).
In the above numerical values, when the peak value is A, the high load cumulative value is B, the total cumulative value is C, and the high load maintenance time is S, the predicted value N of the pullout strength is calculated by the following equation (1). (S202).

  When the calculated predicted value N of the pullout strength is equal to or less than a predetermined reference value, for example (please inform us of specific numerical values), the monitor 110 displays a display indicating that the pullout strength is insufficient, for example, “NG”. Is displayed, and when the reference value is exceeded, a display indicating an appropriate pulling strength, for example, “OK” is displayed (S203).

Next, a method for driving the anchor 2 using the prediction result obtained by the driving system 1 will be described.
When the anchor 2 is driven using this driving system 1, first, it is assumed that the anchor 2 is driven at a standard interval that is widely used for laying the grass prevention sheet 4.

  Then, each time the anchor 2 is driven, the pullout strength of the anchor 2 is predicted for each anchor 2 driven by the above prediction process, and the operator determines whether the pullout strength related to the anchor 2 driven immediately before is appropriate. This is recognized through the display on the monitor 110.

  After the anchor 2 is driven, when the pullout strength of the anchor 2 is appropriate, that is, when “OK” is displayed on the monitor 110, the next anchor 2 is driven so that a predetermined standard interval is obtained.

On the other hand, after the anchor 2 is driven, if the pullout strength of the anchor 2 is equal to or less than a predetermined reference, the next anchor 2 is driven into the anchor 2 that has already been driven at an interval narrower than the standard interval. Like that.
This narrow interval is, for example, half of the standard interval.

More specifically, for example, if the standard interval is 1 m, the narrow interval is 0.5 m.
For this reason, around the anchor 2 having a weak pull-out strength, the driving density of the anchor 2 is increased, and a strong wind blows off the surface of the weedproof sheet 4 so that the weeding sheet 4 is turned upward or peeled off. Even if it acts, in the vicinity of the anchor 2 having a weak pull-out strength, the pull-out force acting on one anchor 2 is distributed to the adjacent anchor 2 driven at a narrow interval.

As a result, when the anchor 2 is driven using the system 1 described above, the weedproof sheet 4 can be reliably locked to the surface of the soil 5 as a whole.
For example, when the anchor 2 is driven onto the rectangular weedproof sheet 4, generally, the anchor 2 is driven in order one by one along one side from one corner of the weedproof sheet 4. .

When the driving of one row is finished and the driving of the next row is started, the interval between the previous row and the next row is a standard interval.
In the next row, the anchor 2 is driven in the same manner as the previous row.
When the front row anchors 2 positioned in parallel to the next row anchors 2 are driven at a narrow interval, the two anchors 2 and the next row anchors 2 are arranged in the middle as a result. It is recommended that another anchor 2 having a narrow interval with the anchor is driven in to increase the density at which the anchor 2 is driven.

In addition, as the standard interval, for example, depending on the type of soil, a predetermined default value, a general-purpose default value irrelevant to the type of soil, the result of conducting a pull-out test at a part of the construction site It is possible to select freely according to the construction environment, such as a set value set accordingly.
Further, the above-mentioned narrow interval may not be half of the standard interval, and can be freely set as long as it is narrower than the standard interval.

Next, using FIG. 5 and FIG. 4, the test conducted in order to specify said Formula (1) is demonstrated.
FIG. 5 is a graph showing transitions of current values obtained at three points with different pulling strengths by the system of FIG. 1, and FIG. 6 is an explanatory diagram showing arrangement items for generating analysis data in the graph of FIG.

First, current values were measured when the anchor 2 was driven at three points with different pullout strengths.
The pullout strength at each point was 0.5 kN, 1.1 kN, and 3.2 kN, and was obtained by performing a general-purpose pullout test on each anchor 2 driven for the test.

The measurement results are as shown in FIG.
From these graphs, it was found that the longer the time required for driving the anchor 2 or the larger the current value, the higher the resistance during driving and the higher the pull-out strength.

Therefore, the elements included in these graphs are organized into the following items shown in FIG. 6, and the correlation is specified using these organized items as explanatory variables for the drawing strength.
A: Peak value at the end (A)
B: Cumulative value (A) with a current value of 3.0A or more
C: Cumulative value from start to finish (A)
T: Time when current value is 3.0 A or more (S)

Based on the above, the transition of the current value and the pull-out strength were measured at a total of 51 locations as in the test of FIG.
Then, using the test results obtained at the 51 locations as analysis samples, multiple regression analysis was performed based on the above four explanatory variables, and the above formula (1) was specified.
The coefficients obtained by this multiple regression analysis are as shown in Table 1 below.

  Then, using the above analysis sample, the correlation between the predicted value of the pullout strength predicted by the above formula (1) and the pullout strength that is the true value was verified. As shown in FIG. 2, it was 0.937, and a very high correlation was confirmed.

  In the above embodiment, each time the anchor is driven, the pullout strength of the anchor that has been driven can be confirmed. Even in heterogeneous soil, the anchor is fixed at an optimum density for locking the weedproof sheet. You will be able to type in.

  In addition, information on the pullout strength of each anchor is presented to the worker objectively and uniquely immediately after the anchor is driven, and therefore depends on the skill level and ability of the worker. Without any problem, the proper locking of the weedproof sheet to the soil can be carried out easily, reliably and quickly.

  In addition, the herbicidal sheet constructed according to the above examples is excellent in wind resistance, hardly peels off or turns up even in strong winds, makes maintenance work extremely easy, and can reduce maintenance cost.

In the above embodiment, any type of electric drill may be used, and the prediction processing device may be integrated with the electric drill in advance.
Further, the order of obtaining the peak current value, the high load accumulated value, the overall accumulated value, and the high load maintenance time may not be the order described in the above-described embodiments.

Also, when the current value consumed by the electric drill is measured corresponding to the time required for driving, and at least one of the current value and time is lower than a predetermined reference value. It may be predicted that the pull-out strength is weak.
Moreover, the object into which the anchor is driven is not limited to soil.
Furthermore, the present invention can be freely modified within the scope of the present invention, and is not limited to the above embodiments.

  In the present invention, each time the anchor is driven, the pull-out strength of the anchor that has been driven is quickly predicted. For example, the herbicidal sheet can be efficiently and reliably locked to the soil, and the high-quality grass-proofing can be achieved. The sheet can be laid at low cost, so it is highly usable.

DESCRIPTION OF SYMBOLS 1 Driving system 10 Electric drill 11 Prediction processing apparatus 110 Monitor 111 Operation panel 2 Anchor 3 Washer 4 Weed prevention sheet 5 It is soil.

Claims (6)

A method for predicting the pullout strength of an anchor,
Using an electric drill to drive the anchor;
A step of measuring the current value consumed by the electric drill during the driving operation of the anchor in correspondence with the time required for driving;
Comparing at least one of the time required from the start of driving the anchor to the end of driving and the accumulated value of the measured current value with a predetermined reference value, the pullout strength of the anchor driven into the driving position is predicted. A method for predicting the pullout strength of the anchor, comprising: The step of predicting the pulling strength is
The peak value of the current at the end when the driving of the electric drill motor stops by the end of anchor driving,
A high load cumulative value that is a cumulative value of a current value that is equal to or greater than a predetermined current value, excluding the time when motor driving is started, among the measured current values during anchor driving,
The total cumulative value that is the cumulative value of the current value measured from the start of driving the motor of the electric drill by the start of anchor driving until the end of the driving,
The method for predicting the pullout strength of the anchor according to claim 1, wherein the pullout strength is predicted by obtaining a high load maintenance time indicating a time during which a current value equal to or greater than the predetermined current value is measured.   The anchor pull-out strength prediction method according to claim 1 or 2, wherein the anchor is driven into the soil in order to lock the herbicidal sheet to the surface of the soil. The method for predicting the pullout strength of an anchor according to claim 3, wherein the predicted pullout strength value N is specified by the following equation (1):

In the formula (1), A is a peak value, B is a high load accumulated value, C is an overall accumulated value, and S is a high load maintaining time.   The anchor pull-out strength prediction method according to any one of claims 2 to 4, wherein the predetermined current value is 3.0A.   When the pullout strength predicted by the anchor pullout strength prediction method according to any one of claims 1 to 5 is equal to or less than a predetermined pullout strength, an interval between anchors driven around the predetermined pullout strength is set to a predetermined pullout strength. An anchor driving method in which the distance between anchors driven around the anchor exceeding the strength is made narrower, and the density at which the anchors are driven is changed according to the predicted pullout strength.

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