JPS59100811A - Method for measuring horizontal displacement by using inclinometer - Google Patents

Abstract

PURPOSE:To find out precise horizontal displacement from which zero drift is erased by reading out the multiplied value between the angle of inclination of the positive/negative direction of an inclinometer and a half value of a reference point distance directly by an indicator and adding the difference between these multiplied values. CONSTITUTION:The sensitivity of the inclinometer 2 is set up so that the multiplied value between the angle of inclination of the inclinometer 2 and a half value DELTAl/2 of the reference point distance DELTAl can be read out directly as a value of the indicator. The inclinometer 2 is moved along the main moving surface of the guide pipe 1, an indication value X+ of the inclinometer 2 is read out and recorded for every prescribed measuring pitch from reference depth, and after turning the inclinometer 2 around the axis by 180 deg., an indication value X- is read out and recorded in the same manner. Thus, the horizontal displacement erasing zero drift included by the inclinometer 2 and the indicator is obtaind by finding out the difference (X+-X-) of the recorded indication values at the same depth of the inclinometer 2.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for measuring horizontal displacement using an inclinometer, and more specifically, the present invention relates to a method for measuring horizontal displacement using an inclinometer, and more specifically, the invention relates to a method for measuring horizontal displacement using an inclinometer. The present invention relates to a method of measuring horizontal displacement corresponding to the inclination of the inclinometer using an inclinometer that measures deformation of a guide pipe and an indicator that receives the output of the inclinometer and indicates a measured value.

In the past, horizontal displacement measurement using an inclinometer was performed as follows. In other words, a so-called roller-type inclinometer is supported by a plurality of rollers rolling on the inner wall surface of the guide pipe, and is moved through the guide pipe while always aligning with the center of the guide pipe. The angle of inclination was measured using an indicator that indicated the measured value of , and a predetermined calculation was performed based on the angle of inclination to determine the horizontal displacement.

Measuring deformation in structures, underground, etc. is an indispensable task for verifying the stability, or safety, of structures, etc. Especially in structures, etc., it is necessary to measure deformations over several months or years. is necessary.

The problem with long-term measurements like this is that the zero point indication (vertical line indication) that the meter has during the measurement period
The problem was that there was a slight fluctuation (zero drift) due to ambient environmental conditions such as humidity, temperature, and vibration. For example, when determining a ground deformation curve using a roller-type inclinometer, if a drift occurs in the instrument, the amount of drift is accumulated for each cumulative calculation, resulting in a large measurement error at the final point. Therefore, to measure the inclination angle, first place the inclinometer on the main moving surface of the guide pipe and read the positive direction indication value, then turn the inclinometer to 18
A method has been used to eliminate the zero drift h by inverting it by 0°, applying it to the passive surface, reading the indicated value in the negative direction, and taking the difference between the two readings.

The principle will be explained below.

When the measured value of the active surface of the guide pipe is Ra, the measured value of the passive surface is Rp+the actual inclination angle at that time is d, and the zero drift is β, the following relational expression holds true.

几a-α+β (1) Rpconi-+β (2) na-Rp=2α (3) 几a 10Rp = 2β (4) Here, conventionally, the inclination angle itself is measured, and in addition, in this measurement, It is a necessary condition that both surfaces of the guide pipe are parallel over each measurement depth, and that the zero drift β is constant at least at the same measurement point during the measurement.

In this way, the actual inclination angle α is determined using equation (3). Set the pointer scale of the indicator to 001°, and set the indicated value to 1.
The angle of inclination can be determined by dividing by 00.

By setting the measurement pitch of the inclinometer using the inclination angle α obtained as described above, the section displacement of the guide pipe from the vertical line at the measurement pitch, that is, the horizontal displacement δ can be obtained.

Furthermore, by sequentially accumulating this horizontal displacement δ for each measurement pitch, it is possible to grasp the shape of the guide pipe and, by extension, the entire deformation of the object to be measured.

Furthermore, by testing the value of zero drift β in equation (4), if this value fluctuates significantly, it can be determined that it is an inappropriate value.

Conventionally, the drawback of the method of measuring the deformation of a measurement object using the above method is that the output of the indicator is an angle, so it is necessary to calculate the sine of this value or convert it to radians, and then The section displacement of the guide pipe with respect to the vertical line, that is, the horizontal displacement δ, is calculated by multiplying the measured pitch of
had to be calculated, and the calculation work was complicated because the number of measurement points was usually very large. Second, it is difficult to intuitively grasp the deformation of the guide pipe, and even if it were possible, it would depend heavily on experience.

The present invention has been made in view of the above circumstances, and uses an inclinometer that allows easy reading of the indication from the indicator and allows easy determination of the horizontal displacement value with zero drift eliminated by calculations that involve only addition and subtraction. The purpose is to provide a horizontal displacement measurement method.

The present invention will be described in detail below based on the drawings.

FIG. 1 is a schematic diagram for explaining one embodiment of the method of the present invention. In the figure, reference numeral 1 denotes a guide pipe buried in the object to be measured (in this case, underground), which has a certain degree of flexibility so that it deforms according to underground deformation, and has at least a circumference in which the inclinometer 2 slides. The walls are parallel to each other. The inclinometer 2 has two legs 3, 3 pivotally attached to the center of both ends thereof, and four hanging rollers 4 each pivotally supported at the tips of the legs 3, 3.
Therefore, it is fitted into the guide pipe 1 so as to be aligned with the axis of the guide pipe 1. Thus, the inclinometer 2 is raised and lowered by a winch installed on the ground via a rope 5, and the output of the inclinometer 2 is sent to an indicator installed on the ground via a cable (not shown). (not shown).

The section horizontal displacement δ of the inclinometer 2 from the vertical line 6 is the inclination angle θ
(radians) and gauge length △l, but in this example, the inclination angle θ (radians) of the inclinometer and gauge length △
The output sensitivity of the inclinometer is set so that the value multiplied by the half value Δl/2 of l can be directly read as the indicated value of the indicator. This setting is based on the value X+ when measuring the main moving surface (positive tilt angle measuring surface) of guide pipe 1 to eliminate the zero drift of the indicator, and the value
This is to read the value X- when the driven surface (negative direction inclination angle measurement surface) of the guide pipe 1 is inverted and to determine the horizontal displacement δ using the following equation.

2δ=X+-X-(5) In other words, when performing the above calculation to find the value of the horizontal displacement δ, there is no need to divide the difference between the measured values X0 and X- by 2, just add and subtract. This is to help my uncle survive. More specifically, the indication scale for both the positive and negative directions of the indicator is set to the 002-002 scale. However, the value displayed on the indicator 2 is multiplied by 100 to make it easier to read, so read it as it is and shift the decimal point by two places when organizing the data.

Next, the gauge length Δl is 500mm, and the measurement upper limit inclination angle θ is ±
5° (that is, a capacity of 5°) will be explained below.

If the gauge length △l is set to 500 dragons, the horizontal displacement δ = 0
．． The inclination angle θ for 02m1 is 4×10−′ radians. If the capacity of the inclinometer 2 is 5°, the output from the indicator is 4. When OX 10-' radian/1 scale, it becomes 2181.7 scales. Therefore, the rated output sensitivity of inclinometer 2 at capacity 5° is set to 2181.7 με (1 μ
By adjusting the output of the indicator to 1με/1 scale, that is, the indicator is set to o, o2+n/1 scale for the horizontal displacement δ in the section. can.

The above rated output sensitivity was determined by the capacity 5 in the prototype of this example.
It is extremely easy to reduce the sensitivity to 2181.7 με.Finally, in order to finely adjust the rated output sensitivity, it is necessary to use a strain gauge as a tilt sensing element. When a constant current power source is applied to the input end of the bridge circuit, adjustment can be easily made by inserting a variable resistor in parallel to the input side of the bridge circuit.

An example of measuring the deformation of the object to be measured using the inclinometer adjusted as described above will be described below. FIG. 2 is a chart arranging the read values and calculated values, and FIG. 3 is a graph plotted based on FIG. 2 to show the state of horizontal displacement with respect to each depth.

First, the inclinometer 2 is inserted into the guide pipe 1 provided in the object to be measured (underground in this case) up to the lowest end, that is, the reference depth. The depth M at this time is 2.0 m, and it is written at the bottom of M in FIG. 2, and each position at that time is set to 0. Next, pull the inclinometer upward by the same length as the measurement pitch 500■, that is, the gauge length Δl, and the depth M == 1.5
Enter the measured value X0 of the active surface and the measured value X- of the passive surface of the guide pipe l at m in the columns X0 and X- in Figure 2 as they are on the indicator, and calculate the section horizontal displacement δ-X+ -X- and cumulative displacement εδ are calculated and entered. Repeat this operation to create a table. Here, the measurement of X- is carried out by taking out the inclinometer 2 from the guide pipe 1 and inverting it by 180 degrees about the axis of the inclinometer 2 after all the measurements of X+ have actually been completed.

In Figure 2 tabulated in this way,
The value of - is multiplied by 0.02 to represent the actual value (including zero point drift of 1-), and the value of δ and εδ is multiplied by 001 to represent the actual value with zero point drift eliminated.

FIG. 3 shows the values of horizontal displacement δ plotted from the table created as described above. In the figure, the horizontal axis shows the horizontal displacement δ, and the vertical axis shows the depth M.

As a result, the horizontal displacement as a deformation of the measurement target (underground),
In other words, it is possible to detect the deformation of the ground.

According to the above method, the interval displacement δ can be sorted out only by subtraction, and the cumulative displacement tδ can be sorted out only by addition. Therefore, horizontal displacement can be grasped even by mental calculation, and underground deformation can be grasped intuitively.

The present invention is not limited to the above-described embodiments, and various modifications are possible.

For example, in the above description, the one with a capacity of 5° was shown, but it is possible to select the upper limit of the measurement inclination angle within the allowable range of the θ key 5irl and the inclinometer itself, and adjust the rated output sensitivity according to that value. By manufacturing the measurement pitch and the measurement pitch, it is possible to manufacture an inclinometer and an indicator that can directly read the multiplication value of the inclination angle θ (radian) and the half value of the gauge length Δl.

As detailed above, according to the present invention, the indicator directly reads the multiplication values X0 and X- of the positive and negative inclination angles θ of the inclinometer and the half value γ of the gauge length Δl, and By simply adding the difference between the multiplication values X+ and X-, zero drift 1
It is possible to provide a method for measuring horizontal displacement using an inclinometer that can easily determine accurate horizontal displacement in which - is eliminated.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram for explaining one embodiment of the present invention, Fig. 2 is a chart showing measurement results and calculation results, and Fig. 3 shows the relationship between horizontal displacement δ at each measurement depth M in Fig. 2. This is a graph showing. ■... Guide pipe, 2... Inclinometer, 3... Legs, 4... Roller,
5...Rope, θ...Inclination angle,
δ...Section horizontal displacement, △l...Gage length. Figure 1 Figure 2 Figure 3 A<Thousands of meals a8

Claims (1)

[Claims] (1) An inclinometer that is inserted into a guide pipe installed in an object to be measured such as a structure or underground and measures the deformation of the object as a deformation of the guide pipe, and measurement based on the output of the inclinometer. In a method of measuring a horizontal displacement corresponding to the inclination of the inclinometer using an indicator that indicates a value, the multiplication value of the inclination angle (radian) of the inclinometer and the half value of the gauge length ΔB is determined by the indicator. The output sensitivity of the inclinometer is set so that it can be directly read as an indicated value. Read and record the indicated value X0 of the inclinometer, then cross the inclinometer 180 degrees around the axis and place it along the passive surface of the guide pipe, and similarly record the indicated value of the inclinometer for each measurement pitch.
By reading and recording x- and determining the difference (X+1X-) between the readings thus recorded at the same depth of the inclinometer, the zero drift contained in the inclinometer and the indicator is eliminated. A method for measuring horizontal displacement using an inclinometer, characterized in that the horizontal displacement is determined.