JPS6073911A - Tension test method and tension test device for ground anchor - Google Patents

Abstract

PURPOSE:To provide accurate and high reliability, by a method wherein elongation is continuously measured by measuring the moving distance of a wire material on which a specified tension is applied, while a pressure is continuously measured, and a relation between a tension power and elongation is continuously checked. CONSTITUTION:When a projection 1a of a tensional material 1 is moved toward a pulley 9, since a weight 10 is attached to the other end of a wire material, attached to the projection 1a by means of a locking tool 7, through the medium of the pulley 9, the wire material 8 is moved in the direction of the weight 10. Thereafter, the pulley 9 is rotated by a full amount, equivalent to the moving distance, motivated by friction between the wire material 8 and the pulley 9. From the rotary angle of the size of the pulley 9, elongation of the stretched material 1 can be easily measured, and based on the tension force of the tensional material and measurements of elongation, tension test data are made. This completes a report simultaneously with completion of a tension test, the drawn up report has accurate and high reliability, and can contribute to the construction management immediately.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a tension testing method and tension testing device for tendons used for construction management of ground anchors.

Ground anchors are made by inserting a tension material such as a steel rod or steel 61 wire into the ground, wrapping the predetermined length of its tip with cement paste or cement mortar, and fixing it integrally to the ground to form an integrated anchor. The other end of the tension material protruding from the ground surface is tensioned using a hydraulic jab, using the ground surface as a reaction force, and the tension material other than the anchor is caused to elongate due to the elasticity of the scraps in proportion to the tension force. By fixing it to the ground surface, it applies compressive force to the ground and prevents loosening of the ground and landslides.

In the above-mentioned ground anchor, the relationship between the tension and elongation generated in the tendon material has a significant influence on the compressive force applied to the ground, so accuracy and high reliability are required in the tension test.

However, in conventional tension tests, changes in the pressure of the pressure oil supplied to the hydraulic jack are stopped at appropriate time intervals, the pressure at that time is measured, and a ruler is fixed to the tension material protruding from the hydraulic jack. Measure the elongation of the tension material using a measuring trundle foot, and after the test is completed, create a table of the relationship between the tension force and elongation of the tension material based on the above measured values, and create a graph from this table to display the data of the tension test. There is a lot of manual work such as making
Furthermore, there are drawbacks such as errors caused by individual differences, making it difficult to obtain accurate and reliable data.

The object of the present invention is to provide a vi tension test method and a tension test device that eliminate the above-mentioned drawbacks,
The tension test method of the present invention, which meets the above objectives, involves tensioning a tension member anchored in the ground using a hydraulic jack, and using the elongation that occurs in the tension member as described above, the movement of a wire attached to the tension member to which a constant tension is always applied. The method is characterized in that the relationship between tension and elongation of the tendon material is continuously investigated by continuously measuring the amount by measuring the amount, and by continuously measuring the pressure applied to the hydraulic jack with a pressure detector. , the tension test device includes an elongation measuring device that continuously measures the elongation of the tension material in the ground anchor, a pressure detector that continuously measures the pressure applied to the hydraulic jack, and the elongation measuring device and pressure detector described above. a microcomputer that processes the data from the computer, a setting device that presets numerical values necessary for the calculation process, a plotter that records the data processed by the microcomputer, and a plotter that displays the data. It is characterized by being equipped with a display.

The present invention will be described in detail below with reference to embodiments of the accompanying drawings.

Figure 1 shows the cross-section of the ground anchor in the ground and the state of measurement of the elongation of the tendon during tension, Figure 2 is an enlarged view of the part where the elongation of the tendon is measured, and Figure 3 shows the pressure oil in the hydraulic jack. Figure 1 shows a circuit diagram of an example of a hydraulic system for supplying .

In Figure 1, 1 is a tendon of a ground anchor inserted into the ground 2, and 3 is a predetermined length of cement paste or cement mortar injected into the tip of the tendon 1 in the ground, rolled and solidified, and integrated into the ground. 4 is a jack seat for transmitting the reaction force of the hydraulic jack 5 to the ground; 6 is a fixed part for holding the tension material 1 stretched by the hydraulic jack 5; 1a is the hydraulic jack 5; A wire rod 8 for elongation measurement is attached to the projection portion 1a via a stopper T, and the wire rod 8
A weight 10 is attached to the other end via a pulley 9 so that a constant tension is always applied to the wire 8. As shown in FIG. 2, the rotation of the pulley 90 is configured to be transmitted to the rotation angle detector 11, and the pulley 9 and the rotation angle detector 11 are configured to transmit the rotation of the pulley 90 to the rotation angle detector 11. It is provided on a pulley stand 12 installed at a location that does not affect displacement.

Further, 5 in FIG. 3 is a hydraulic jack, 5a is the cylinder side, 5b is the piston side, 5c is the A boat which is the inlet of suppressing pressure oil, and 5d is the B boat on the pulling side.

The hydraulic jack 5 is provided with a pressure detector 13 via a port A) 5ct, and the hydraulic jack 5 is connected to the oil tank 1B.
In between, there is a switching valve 14 that operates the hydraulic jack 5, a hydraulic pump 15 that generates all the pressure oil, a pressure regulating valve 16 that adjusts the entire pressure, and a filter 17. and a throttle valve 19 are provided.

FIG. 4 shows the entire tension testing device, and 20 is an elongation measuring device 1 for measuring the elongation of the tension material 1 from the rotation angle and diameter of the pulley 9;
3 is a pressure detector for detecting the pressure which is basic data for measuring the tension generated in the tension member 1 by the hydraulic jack 5; 21 is a pressure detector for each IIi value necessary for the calculation processing performed by the microcomputer 22; The setting device 23 stores special data during the stress test in addition to the values set in the setting device 21, and sends this to the microcomputer 22 as needed.
24 is a plotter that continuously records and plots the relationship between tension and elongation of the tension material 1 from the start of the test to the end of the test. In addition to being used to confirm the setting data input from the setting device 21, this display is designed to display the tension and elongation during the test so that it can be read at any time.

In FIG. 1, when the tension member 1 anchored in the ground by the anchor unit 3 is tensioned via a holder (not shown) provided on the hydraulic jack 5, the tension member 1 between the anchor unit 3 and the holder is tensioned. 1 is stretched, and the protrusion 1a of the tendon 1 moves toward the pulley 9 by the length of the stretch.

In order to tension the tension material 1 with the hydraulic jack 5, the switching valve 14 is operated so that pressure oil flows from the A port 5c of the hydraulic jack 5 shown in FIG. 3, and the hydraulic pump 15 supplies the pressure oil. do.

At this time, either adjust the discharge amount of the hydraulic valve 15 or press the pressure a! 4 Adjustment valve 16fi - If you want to gradually lower the pressure of the tension changer 5, set the switching valve 14 to neutral to stop the flow of pressure oil to the hydraulic jack 5 and stop the hydraulic valve 15. and close the throttle valve 19. Next, when the switching valve 14 is operated to gradually open the throttle valve 19, the piston side 5b of the hydraulic jack 5 returns due to the expansion of the tension material 1, and the tension force decreases, so it is sufficient to observe the data t-U at this time. .

The tension force is measured by multiplying the value of the pressure detector 13 installed on the A-sc side of the hydraulic jack 5 by the pressure receiving area of the cylinder side 5a of the hydraulic jack 5. A load detector that can directly measure the tension force may be provided between the and the jack seat 4.

As described above, when the protrusion 1a of the tension member 1 moves toward the pulley 9, the weight 10 is attached via the pulley 9 to the other end of the wire 8 attached to the protrusion 1a by the stopper I. Therefore, the wire rod 8 moves toward the weight 10 as much as the tension member 1 extends.As shown in the diagram, since the rotation angle detector 110 is directly connected to the rotation shaft, the rotation angle detector 110 moves as much as the pulley i rotates. 11fr, the rotation angle detector 11 can output an electrical displacement corresponding to the rotation angle. This electrical displacement may be a digital type that outputs a pulse at every fixed angle, or an analog type that outputs a pulse in proportion to the rotation angle. If the rotation angle of the pulley 9 is known by the method described above, the amount of movement of the wire rod 8, that is, the elongation of the tension material 1 can be easily measured based on the rotation angle of the pulley 90 and the diameter.

The weight of the weight 10 is sufficiently small compared to the strength of the wire rod 8, and by making the weight so as not to cause the wire rod 8 to bend, the influence of elongation of the wire rod 8 can be ignored, and the hydraulic jack 5 By installing the pulley stand 12 in a place where it will not be affected by the displacement that occurs in the ground m2 due to the reaction force, the elongation of the tendon 1 can be accurately measured.

Next, a method of creating tension test data based on the measured values of the tension force and elongation of the tendon material will be explained with reference to FIG.

When the tension test is started by inputting data necessary for arithmetic processing into the storage unit 23 via the setting device 21 and the microcomputer in advance, the microcomputer 22 operates according to a predetermined program to measure elongation. The elongation data input from the device 20, the tension data input from the pressure detector 13, and the data stored in the storage unit 23 are processed, and numerical values for creating a test data table are stored in the storage unit 2.
3, and block 24 immediately and continuously draws a relationship diagram between tension and elongation. Then, after the test is completed, the plotter 24 plots a test data table based on the above-mentioned numerical values stored in the storage unit 23 for creating a test data table, and creates a tension test report using the above-mentioned relationship diagram between tension force and elongation. complete.

In FIGS. 1 and 2, the weight 1o is used to always apply a constant tension to the wire 8, and is used not only to hang the wire rod 8 from the pulley 9 as shown in FIGS. The wire rod 8 may be constructed so as to be convex and movable, or a special spring may be used to apply a constant tension to the wire rod 8 at all times. Furthermore, the method for measuring the elongation of the tendon material is not limited to the embodiments, and the data sent from the elongation measuring device 20 explained in FIG. 4 to the microcomputer 22 may be the elongation of the tendon material. It may also be the rotation angle of the pulley. When the data is the rotation angle of the pulley, the numerical value for calculating the total elongation based on the diameter and rotation angle of the pulley is set in the setting device, and the elongation is calculated by the microcomputer.

Since this invention is structured as shown in #, the report is completed at the same time as the test drive is completed, and there is no need to manually create the report each time, as in the past. These reports have many benefits, such as being accurate and highly reliable, and can be immediately used for construction management.

[Brief explanation of the drawing]

The attached drawings show embodiments of this invention, and the first
The figure shows the cross-section of the ground anchor in the ground and the state of measurement of the elongation of the tendon during tension. Figure 2 is an enlarged view of the measuring section for the elongation of the tendon. Figure 3 shows the application of pressure oil to the hydraulic jack. Figure 1 is a circuit diagram of an example hydraulic system for supplying a tension test device; 1... Tension material 2... Ground 5... Hydraulic jack 8... Wire rod 13... Pressure detector 20... Elongation measuring device 21... Setting device 22... Microcomputer-24 ... Plotter 25 ... Display 1st
Figure 3 Figure 8 Figure 4

Claims (2)

[Claims] (1) A tension member anchored in the ground is tensioned using a hydraulic jack, and the elongation that occurs in the tension member is continuously measured by measuring the amount of movement (t) of a wire attached to it and constantly under constant tension. A tension test on a ground anchor, characterized in that the pressure applied to the hydraulic jack is continuously measured with a pressure detector, and the relationship between the tension force and elongation of the tension material is continuously investigated. Law. (2) An elongation measuring device that continuously measures the elongation of the tendon in the ground anchor, a pressure detector that continuously measures the pressure applied to the hydraulic jack, and data from the elongation measuring device and pressure detector. It is equipped with a microcomputer that performs calculation processing, a setting device that presets numerical values necessary for the calculation processing, a plotter that records the data processed by the microcomputer, and a display device that displays the data. A tension testing device for ground anchors, which is characterized by: