JPH1114476A - Earth pressure measuring method using clinometer and safety managing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the safe, speedy, and accurate prediction of danger by computing the tension of an anchor line from a measured value obtained by the measurement of the inclination displacement of a solder pile or an anchor supporting part to compute earth pressure. SOLUTION: A soldier pile 1 is vertically planted, and the tip end side of a PC steel wire 3 (anchor line) derived at an angle 45 deg. from an anchor 2 is tightened and fixed to the supporting part 4 of the soldier pile 1. Then an inclination detector 6 is provided on the bracket 5 of the soldier pile 1, and the output of the inclination detector 6 is connected to a control unit by a cable. As the soldier pile 1 is moved backward when the soldier pile 1 receives the earth pressure 10 of a slope 9, the inclination of the soldier pile 1 is measured by the inclination detector 6, and its output is inputted into the control unit. Then the tension of the anchor line is computed in the control unit and is displayed. Therefore, in the case that a computed numeric value is smaller than a predetermined safety value, it is safe. In the case a computed numeric value is larger than the safety value, an alert is immediately issued to ensure safety measures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an earth pressure using an inclinometer for measuring an earth pressure applied to a parent pile or an anchor supporting portion by measuring an inclination displacement of the portion. It relates to a measurement method and a safety management system.

[0002]

2. Description of the Related Art Conventionally, there has been disclosed a technique in which an inclinometer is buried in an inclined portion of cut and embankment to prevent or predict the collapse of the incline (Japanese Patent Laid-Open No. 6-116964).

[0003] In order to prevent a collapse accident of the portion by a soil retaining method or the like, a measuring instrument such as an earth pressure gauge using a cinder or a center hole type load cell is used.

[0004]

Among the above prior arts, the disclosed invention is effective for predicting natural collapse, etc., but if there is a landslide work in that part, the landslide may cause a collapse accident. It has been difficult to determine whether it can be prevented or is within a tolerable amount range. When an earth pressure gauge using a cinder or a center hole type load cell is used, it has its own characteristics, but also has the following problems. That is, since the amount of earth pressure is enormous, handling is difficult, and the load varies from site to site (for example, 50 tons, 100 tons, 150 tons, etc.),
You must prepare the equipment corresponding to each.

[0005] In addition to the load being directly applied to the measuring instrument, the direction in which the load is applied is unlikely to be a right angle, and the measuring instrument may be degraded or damaged due to the unbalanced load.

[0006] Many measuring instruments need to be installed before tensioning of an anchor wire or the like, and it is necessary to go to an installation place for measurement. Therefore, it is often difficult to detect the occurrence of an abnormality beforehand, and there have been problems such as an installation place being at a high place and other places having poor workability.

[0007]

However, according to the present invention, since the earth pressure is calculated by measuring the inclination displacement of the parent pile or the anchor support used for the earth retaining, the danger prediction can be performed safely, promptly and accurately. This solves the conventional problem.

That is, the invention of the method is characterized in that a measured value obtained by measuring the inclination displacement of the parent pile or the anchor support portion is input, the tension of the anchor wire is calculated, and the earth pressure is calculated thereby. This is a method of measuring earth pressure.

Further, the invention of the system is characterized in that the inclination displacement of an arbitrary number of parent piles determined under certain conditions is centrally managed, and whether the amount of inclination displacement is within an allowable set value is centrally managed. Is a safety management system using an inclinometer, the tilt displacement converts the measured value of the tilt angle detector into an electric signal,
The output is input to a management device to manage the tension at each measurement point.

[0010] According to the invention, the installation of the inclination angle detector can be easily performed at the time of earth retaining work, and the output of the inclination angle detector can be converted into an electric signal and centrally managed at a remote place.
Therefore, it is possible to easily monitor a vast earth retaining site at one place, and also to easily monitor a large earth retaining site at a plurality of earth retaining sites. In addition, if an automatic recording device is attached to a display or the like, continuous recording can be accumulated unattended, and if an automatic transmission device is attached, part or all of the continuous recording can be transmitted to any place and monitored. Of course, grasp the actual state of tilt displacement,
In addition to being able to predict dangers, it is possible to accumulate materials for safe and secure earth retaining work, and to provide appropriate materials for various conditions (for example, soil quality, slope angle of slope, rainfall, etc.).

In the above invention, if the inclination angle detector is set on the mounting base of the parent pile, the inclination of the parent pile can be accurately captured, and no external force can be applied. There is no risk of deterioration, breakage or loss of accuracy.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is characterized in that the inclination displacement of a parent pile or an anchor supporting portion is measured, the input is calculated, the tension of the anchor wire is calculated, and thereby the earth pressure is calculated. It is.

[0013] Further, there is provided a safety management system in which safety management can be performed by centrally managing the inclination displacement of the parent pile and centrally monitoring whether or not the amount of inclination displacement is within an allowable set value.

[0014]

EXAMPLE A parent pile 1 is vertically planted and an anchor 2
The tip end side of the PC steel wire 3 drawn in the 45-degree direction from it is fastened and fixed to the support portion 4 of the parent pile 1, and the inclination angle detector 6 is installed on the bracket 5 of the parent pile 1, The output of the angle detector 6 is connected to a management device 8 for management by a cable 7 (FIG. 2).

In the above embodiment, when the earth pressure on the sloped land 9 is applied to the parent pile 1 as shown by an arrow 10 (in this case, the earth pressure is applied to the earth retaining plate 11, and the earth retaining plate 11 is supported and applied to the parent pile 1). Transmitted), the parent pile 1 retreats to the position indicated by the chain line 1a, so that the inclination angle detector 6 measures the inclination of the parent pile 1a, and the output is input to the management unit 8, and the management unit 8 It is calculated and displayed within and recorded as necessary. Therefore, if the calculated numerical value is smaller than a predetermined safety value, it is safe. If it is larger than the safe value, an alarm is immediately issued and a measure is taken to establish a means for ensuring safety.

The safety value indicates the permissible limit of the PC steel wire. When the safety value is exceeded, the PC steel wire breaks, the parent pile breaks, and the inclined soil moves in the direction of arrow 12. There is a risk of catastrophic migration.

The calculation by the calculator built in the management unit 8 is based on the following equation, for example.

First, in FIG. 2, assuming that the displacement of the parent pile Δd and the displacement angle of the parent pile are θ ₃ ,

(Equation 1) The elongation of PC steel wire is

(Equation 2) Here, A indicates the cross-sectional area of the PC steel wire. E is a Young's modulus. Therefore,

(Equation 3) From the equations (1), (2), and (3),

(Equation 4) Becomes

Since several PC steel wires are used in a bundle, the number of PC steel wires is N, and the cross-sectional area per one is A.
_If it is set to ₀ , the cross-sectional area of the PC steel wire will be A = N · A ₀ . Therefore, the above equation (4) becomes

(Equation 5) In addition, since “θ ₁ is almost the same as θ ₄ ”, the following equation can be used.

[0020]

(Equation 6) And the load value applied to the PC steel wire is the displacement angle θ _{3 of the} parent pile.
Can be calculated by measuring

Therefore, the PC steel wire is referred to as “7 strands wire B type12.
7 mm "(JISG 3536), the nominal cross-sectional area is A ₀ = 98.71 mm ² , and the Young's modulus E =
22 × 10 ³ kgf / mm ² and the driving angle θ
_{If 1} = 45 °, from equation (6), F = N · 98.71 · 22 × 10 ³ (H / L ₁ ) · co
sθ ₁ · sin θ ₃

(Equation 7) Becomes N in the, H, L ₁ is be measured at the construction site, because a numerical value can be seen, it is possible to calculate the load value by measuring the displacement angle.

That is, according to the present invention, if the displacement angle of a parent pile or the like is measured on site, N, H, and L ₁ are numerical values known in advance and can be input as data of a calculator. Since it is possible (or input on site), the tension can be calculated immediately.

The embodiment shown in FIG. 3 is an example of a state in which a tilt angle detector installed on each parent pile and a management device are connected by a cable. In this manner, the earth pressure of the slope land on each parent pile can be immediately notified by looking at the display of the management device. Therefore, the degree of security in terms of management is immediately known.

[0024]

According to the present invention, if the inclination displacement angle of the parent pile is measured and inputted and calculated, the load value applied to the PC steel wire can be accurately calculated. Also, if this calculated value is digitally displayed on the management device, there is an effect that the earth pressure on each slope can be immediately grasped.

Further, since no external force is applied to the tilt angle detector, there are various effects such as deterioration, deformation, and instability of measured values even when used for a long time.

According to the present invention, the measured value of the tilt angle detector is converted into an electric signal and transmitted to the management device. Therefore, the measured value is recorded continuously or intermittently and monitored if necessary. Can be sent to the center. Therefore, not only can one construction site be monitored, but also many construction sites can be easily and unmannedly monitored, and there are various effects such as comprehensive and intensive safety management.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing inclination displacement of a parent pile according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing displacement angles.

FIG. 3 is an explanatory diagram of an embodiment of the same security management.

[Description of Signs] 1 Parent pile 2 Anchor 3 PC steel wire 4 Support section 5 Bracket 6 Incline angle detector 7 Cable 8 Manager 9 Inclined ground 11 Earth retaining plate

Claims (3)

[Claims] 1. An earth pressure measurement method comprising: inputting a measurement value obtained by measuring a tilt displacement of a parent pile or an anchor support portion; calculating a tension of an anchor wire; and calculating an earth pressure by the calculation. Method. 2. An inclinometer characterized by centrally managing the inclination displacement of an arbitrary number of parent piles determined under certain conditions and centrally managing whether or not the amount of inclination displacement is within an allowable set value. Safety management system using. 3. The tilt displacement is characterized in that a measured value of the tilt angle detector is converted into an electric signal, an output thereof is input to a management device, and a tension at each measurement point or a total tension is displayed. A safety management system using the inclinometer according to claim 2.