Cutting face evaluation device

Abstract

To provide a working face evaluation device that can easily and accurately evaluate a state of a working face using a breaker.SOLUTION: A working face evaluation device according to one embodiment is a working face evaluation device 1 for evaluating a tunnel working face K using a backhoe 10 having a base 11 and a breaker 15. The working face evaluation device 1 comprises: a sensor 2 for collecting evaluation indicators at the time of striking of the breaker 15 to the working face K; and a strength calculation unit for calculating the strength of the working face using the evaluation indicators. The evaluation indicator is acceleration, and a vibration acceleration collecting unit of the sensor 2 is an accelerometer.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a face evaluation device for evaluating a face. [Background technology]

[0002] Patent Document 1 describes a method for evaluating the geological quality of the excavation surface, which corresponds to the tunnel face. In this evaluation method, a geophone and a microphone are installed at a predetermined position within the tunnel shaft, a predetermined distance behind the face. Elastic waves and sound waves are generated by striking the excavation surface with various devices, including a breaker or hammer. The geophone measures the elastic waves that propagate through the natural ground when generated by vibration. The microphone receives and measures sound waves that propagate through the air.

[0003] The elastic waves measured by the geophone and the sound waves measured by the microphone are recorded on a computer that starts recording before the vibrations occur. The computer calculates the power spectrum frequencies of the elastic waves and the sound waves from the elastic wave data and the sound wave data. The geological conditions of the excavation surface are then estimated and evaluated based on these frequency characteristics.

[0004] Patent Document 2 describes a method for evaluating the geological features of an excavation surface. In this method, a microphone is installed at a predetermined position a predetermined distance behind the tunnel face. A personal computer is connected to the microphone via a communication cable. A certain crushing force is applied to the tunnel face to generate crushing sounds, and the crushing sounds propagating through the air are collected by the microphone.

[0005] The above-mentioned crushing sounds are recorded on a computer that starts recording before the sound is generated. The computer records sound wave data of the crushing sounds of multiple types of tunnel faces. The computer calculates the frequency characteristics of the sound waves from the sound wave data, and estimates and evaluates the geological conditions of each tunnel face based on the frequency characteristics of the sound waves for each tunnel face. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-197389 [Patent Document 2] Patent Publication No. 2021-96140 Summary of the Invention [Problem to be solved by the invention]

[0007] For example, in ground construction, in order to rationally select a support pattern, it may be necessary to easily and accurately evaluate the mechanical properties of the excavated ground (such as deformation properties or ground strength). In construction involving hard rock ground, the mechanical properties of the ground may be evaluated from machine data obtained during drilling with a jumbo drill. However, there are currently cases where drilling work using a jumbo drill is not performed, or where there is no equipment to evaluate mechanical properties from machine data obtained using a jumbo drill, and in construction involving mechanical excavation of soft rock or soil, there is a lack of methods for evaluating mechanical properties. Therefore, there is a need to be able to easily and accurately evaluate the condition of the face using a breaker for simple ground excavation.

[0008] The present disclosure aims to provide a face evaluation device that can easily and accurately evaluate the condition of a face using a breaker. [Means for solving the problem]

[0009] A tunnel face evaluation device according to one aspect of the present disclosure is a tunnel face evaluation device that evaluates the tunnel face using heavy machinery equipped with a base and a breaker, and is equipped with an evaluation index collection unit that collects evaluation indexes when the breaker strikes the tunnel face, and a strength calculation unit that calculates the strength of the tunnel face using the evaluation indexes, wherein the evaluation index is acceleration, and the evaluation index collection unit is an accelerometer. The apparatus further includes a breaker impact angle detection unit that detects the impact angle of the breaker, and the strength calculation unit calculates the strength of the face using the acceleration and the impact angle of the breaker.

[0010] In this tunnel face evaluation device, the tunnel face is evaluated using heavy machinery equipped with a base and a breaker. The tunnel face evaluation device is equipped with an evaluation index collection unit and a strength calculation unit, and the evaluation index collection unit, which is an accelerometer, collects acceleration when the breaker strikes the tunnel face. The strength calculation unit calculates the strength of the tunnel face from the acceleration collected by the accelerometer. Strength such as the hardness of the tunnel face can be obtained with high precision from the acceleration generated when the breaker strikes the tunnel face. Therefore, the strength of the tunnel face can be evaluated with high precision by the strength calculation unit calculating the strength from the acceleration. Furthermore, this tunnel face evaluation device can evaluate the strength of the tunnel face by collecting acceleration when the breaker strikes the tunnel face. Therefore, the condition of the tunnel face can be evaluated easily and with high precision using a breaker.

[0011] The face evaluation device may include a breaker impact angle detection unit that detects the impact angle of the breaker on the face, and the strength calculation unit may calculate the strength of the face using the acceleration and the breaker impact angle. The impact force on the face depends on the impact angle of the breaker on the face. For example, a more appropriate impact force can be applied to the face when the breaker is facing downward relative to the direction perpendicular to the face than when the breaker is facing upward relative to the direction perpendicular to the face. Therefore, by having the breaker impact angle detection unit detect the breaker impact angle and having the strength calculation unit calculate the strength of the face using the breaker impact angle, the condition of the face, such as its strength, can be evaluated with higher accuracy.

[0012] A tunnel face evaluation device according to another aspect of the present disclosure is a tunnel face evaluation device that evaluates the tunnel face using heavy machinery equipped with a base and a breaker, and is equipped with an evaluation index collection unit that collects evaluation indexes when the breaker strikes the face, a breaker strike angle detection unit that detects the strike angle of the breaker on the face, and a strength calculation unit that calculates the strength of the face using the evaluation index at the time of strike and the breaker strike angle, wherein the evaluation index is sound and the evaluation index collection unit is a microphone.

[0013] In this tunnel face evaluation device, an evaluation index collection unit, which is a microphone, collects the sound when the breaker strikes the tunnel face, and a breaker strike angle detection unit detects the strike angle of the breaker on the tunnel face. The strength calculation unit calculates the strength of the tunnel face from the sound at the time of impact collected by the microphone and the breaker strike angle. The strength calculation unit calculates the strength of the tunnel face from the sound at the time of impact, taking into account the breaker strike angle, so the strength of the tunnel face can be calculated with high accuracy. Furthermore, this tunnel face evaluation device can collect the sound when the breaker strikes the tunnel face and evaluate the strength of the tunnel face. Therefore, the condition of the tunnel face can be evaluated easily and with high accuracy using a breaker.

[0014] The breaker impact angle detection unit may include a mechanism for detecting the extension direction of the breaker relative to the base as an impact angle. In this case, the extension direction of the breaker relative to the base of the heavy equipment is detected as the impact angle, so the condition of the face can be evaluated with higher accuracy from the detected impact angle.

[0015] This face evaluation device may further include a face angle detection unit that detects the angle of the face of the face, and the breaker impact angle detection unit and face angle detection unit may detect the angle of the extension direction of the breaker relative to the direction perpendicular to the face as the impact angle. In this case, the impact angle is detected from the direction of the breaker relative to the face of the face. Therefore, the state of the face can be evaluated with higher accuracy based on the impact angle detected with high accuracy.

[0016] When an upward angle is a positive angle and a downward angle is a negative angle relative to the orthogonal direction of the cutting face, θ1 is a negative real number, and θ2 is a positive real number, the strength calculation unit may calculate the strength of the cutting face from the evaluation index when θ, the breaker's impact angle relative to the orthogonal direction, satisfies θ1≦θ≦θ2. In this case, the strength of the cutting face is calculated from the evaluation index when the breaker's impact angle relative to the orthogonal direction of the cutting face is within a certain angle range. Therefore, since it is possible to exclude evaluation values ​​where the impact angle is outside the certain angle range, the cutting face strength can be calculated with higher accuracy.

[0017] In the case where an upward direction is a positive angle direction and a downward direction is a negative angle direction relative to the orthogonal direction of the cutting face of the tunnel cutting operation, the strength calculation unit may calculate an evaluation value from the evaluation index and correct the evaluation value by multiplying the evaluation value by a correction coefficient A (where A is a positive real number). The correction coefficient A may be smaller as the absolute value of the impact angle θ of the breaker relative to the orthogonal direction increases. In this case, the smaller the absolute value of the impact angle θ of the breaker relative to the orthogonal direction of the tunnel cutting operation, the larger the correction coefficient A by which the evaluation value is multiplied. Therefore, the accuracy of the evaluation value can be further improved by multiplying an evaluation value with a large absolute value of the impact angle θ relative to the orthogonal direction and low accuracy by a small correction coefficient A, and by multiplying an evaluation value with a small absolute value of the impact angle θ relative to the orthogonal direction and high accuracy by a large correction coefficient A. As a result, the condition of the tunnel cutting operation, such as strength, can be evaluated with higher accuracy. [Effects of the Invention]

[0018] According to the present disclosure, the condition of the face can be easily and highly accurately evaluated using a breaker. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a cross-sectional view schematically showing a natural ground to which a face evaluation device according to an embodiment is applied. [Figure 2] 1 is a side view showing a heavy machine to which a face evaluation device according to an embodiment is applied. [Figure 3] FIG. 2 is a block diagram showing the functions of the face evaluation device according to the embodiment. [Figure 4] 1(a), (b), and (c) are schematic cross-sectional views of natural ground for explaining the impact angle of the breaker against the working face. [Figure 5] 10(a), (b), and (c) are graphs showing examples of the relationship between vibration acceleration level and frequency band. [Figure 6] FIG. 10 is a diagram showing an example of a method for classifying the position of a face in evaluation of the face. [Figure 7] 10 is a graph schematically illustrating an example of the relationship between acceleration level and intensity. [Figure 8]10 is a graph showing data on vibration acceleration levels obtained from a face evaluation device according to an embodiment. [Figure 9] 1 is a graph showing sound pressure level data obtained from a face evaluation device according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the face evaluation device according to the present disclosure will be described with reference to the drawings. In the description of the drawings, the same or corresponding elements are given the same reference numerals, and duplicate explanations will be omitted as appropriate. In addition, the drawings may be partially simplified or exaggerated for ease of understanding, and the dimensional ratios and the like are not limited to those shown in the drawings.

[0021] Fig. 1 is a cross-sectional view schematically showing the natural ground G to which the face evaluation device 1 according to this embodiment is applied. Fig. 2 is a side view showing a backhoe 10, which is an example of heavy machinery to which the face evaluation device 1 according to this embodiment is attached. The natural ground G has, for example, layers G1, G2, G3, and G4, which are arranged in this order from the surface of the natural ground G in the depth direction of the tunnel.

[0022] The strengths of layers G1, G2, G3, and G4 are known, for example, from existing literature data. Layer G4, which is farthest from the surface of the natural ground G, often has the highest strength, while layer G1, which is closest to the surface, has the lowest strength. However, when actually excavating the natural ground G, the strengths of layers G1, G2, G3, and G4 may be unknown. Therefore, it is important to evaluate the strength of the natural ground G along with the excavation. In this embodiment, "natural ground strength" refers to the resistance of the natural ground or a natural ground sample to deformation or fracture. For example, it may be the natural ground strength ratio, which may be a value evaluated by a uniaxial compressive strength test, a triaxial compressive strength test, or a point load tester. In this embodiment, the tunnel face refers to the tip of the excavation in tunnel construction, where the natural ground is exposed or covered with a thin layer of concrete. The face of the tunnel face (face surface) is generally vertical (plumb) or shaped at a predetermined angle.

[0023] For example, a backhoe 10 has a base 11 having a running body (a crawler as an example) and a cabin 11b, a boom 12 extending from the base 11, and an arm 13 attached to the boom 12 so as to be rotatable about an axis extending horizontally of the boom 12. The backhoe 10 further has a breaker 15 attached to the tip of the arm 13 (the end opposite the boom 12). The breaker 15 has a bracket 17 pivotally supported on the tip of the arm 13, and a chisel 16 (rod) attached to the inside of the bracket 17 so as to be reciprocatable, for drilling a face K of a tunnel in the ground G.

[0024] Fig. 3 is a block diagram showing the functions of the tunnel face evaluation device 1. As shown in Fig. 2 and Fig. 3, the tunnel face evaluation device 1 has a sensor 2 attached to a breaker 15, a cable 3 extending from the sensor 2, and an information terminal 4 provided at the end of the cable 3 opposite to the sensor 2.

[0025] The sensor 2 is disposed, for example, at a position closer to the chisel 16 on the bracket 17 of the breaker 15. In this case, the sensor 2 can acquire data with even higher accuracy. The sensor 2 includes various sensors. The sensor 2 has, for example, a vibration acceleration collection unit 2b that collects acceleration (including acceleration waveform) when the breaker 15 (chisel 16) strikes the face K, an impact sound collection unit 2c that collects sound (including sound waveform) when the breaker 15 strikes the face K, and a breaker impact angle detection unit 2d that is an angle detection sensor that detects the impact angle of the breaker 15 on the face K.

[0026] The vibration acceleration collecting unit 2b and the impact sound collecting unit 2c are each an evaluation index collecting unit that collects an evaluation index (an evaluation index of the strength of the working face K) when the breaker 15 strikes the working face K. The evaluation index collected by the vibration acceleration collecting unit 2b is acceleration (including acceleration waveform), and a vibration acceleration level, which is an evaluation value, is derived (calculated) from the acceleration. The evaluation index collected by the impact sound collecting unit 2c is sound (including sound waveform), and a sound pressure level, which is an evaluation value, is derived (calculated) from the sound. For example, the vibration acceleration collecting unit 2b is an accelerometer, and the impact sound collecting unit 2c is a microphone. These sensors 2 are attached to the bracket 17, for example, but may also be attached to the base 11, the boom 12, or the arm 13.

[0027] The cable 3 is, for example, a wired cable. The cable 3 is supported by, for example, the breaker 15, the arm 13, and the boom 12, and extends from the breaker 15 along the arm 13 and the boom 12 to the information terminal 4 arranged inside the cabin 11b. The information terminal 4 is, for example, a mobile terminal, and for example, a tablet terminal.

[0028] For example, data recording software is installed in the information terminal 4, and the operator of the backhoe 10 can record impact data on the ground G by operating the information terminal 4. The impact data on the ground G is at least one of a vibration acceleration level derived (calculated) from the acceleration collected by the vibration acceleration collecting unit 2b, and a sound pressure level derived (calculated) from the sound collected by the impact sound collecting unit 2c. For example, by operating the information terminal 4, a waveform analysis is performed on the impact data on the ground G, and the strength of the ground G is calculated.

[0029] The breaker impact angle detection unit 2d calculates the extension direction of the breaker 15 (chisel 16) relative to the base 11 as the impact angle. As shown in Figures 3, 4(a), 4(b), and 4(c), the device further includes a face angle detection unit 2f that detects the angle of the face K1 of the face K relative to the horizontal plane. The breaker impact angle detection unit 2d and the face angle detection unit 2f more accurately detect the impact angle θ as the angle of the extension direction of the breaker 15 (chisel 16) relative to the direction perpendicular to the face K1. The face K1 is generally formed vertically. Therefore, when detecting the angle of the breaker 15 (chisel 16) relative to the face K1, the breaker impact angle detection unit 2d may consider the face K1 to extend vertically and detect the impact angle θ by detecting the angle of the breaker 15 (chisel 16) relative to the horizontal. The breaker impact angle detection unit 2d is, for example, an inclinometer attached to the bracket 17. However, in this case, the fluctuation in the inclinometer's measurement value may become large, making the measurement of the angle of the breaker 15 unstable. The breaker impact angle detection unit 2d may be an inclinometer provided on the base 11, an angle meter capable of measuring the angle between the base 11 and the boom 12, an angle meter capable of measuring the angle between the boom 12 and the arm 13, or an angle meter capable of measuring the angle between the arm 13 and the bracket 17. In other words, the breaker impact angle detection unit 2d may include a mechanism that detects the extension direction of the breaker 15 relative to the base 11 as the impact angle θ. In this case, the fluctuation in the inclinometer's measurement value is small, allowing for more accurate angle detection. Furthermore, since the base 11 is often placed on a horizontal plane (or a plane perpendicular to the face), only a mechanism that detects the extension direction of the breaker 15 relative to the base 11 as an impact angle θ may be required (i.e., a goniometer that can measure the angle between the base 11 and the boom 12, a goniometer that can measure the angle between the boom 12 and the arm 13, or a goniometer that can measure the angle between the arm 13 and the bracket 17).

[0030] The face angle detection unit 2f that detects the angle of the face K1 may be, for example, an inclinometer that can measure the inclination by being installed along the face K1, or a laser scanner or total station that can measure the shape of the face K1. The inclinometer can detect the angle with respect to the direction of gravity. The inclinometer may also be capable of detecting the angle with respect to the horizontal direction.

[0031] The tunnel face evaluation device 1 has a strength calculation unit 5 that calculates the strength of the tunnel face K using the above-mentioned evaluation index. The strength calculation unit 5 is, for example, software installed in the information terminal 4. The strength calculation unit 5 calculates the strength of the tunnel face K using the evaluation index when the breaker 15 strikes the tunnel face K and the impact angle θ of the breaker 15. For example, the strength calculation unit 5 calculates the strength of the tunnel face K using the acceleration collected by the vibration acceleration collection unit 2b and the impact angle θ of the breaker 15. The strength calculation unit 5 may also calculate the strength of the tunnel face K from the sound collected by the impact sound collection unit 2c and the impact angle θ of the breaker 15.

[0032] The angle of the breaker 15 with respect to the cutting face K1 also has an effect on the calculation of the strength of the cutting face K. As shown in Figure 4(a), when the impact angle θ of the breaker 15 with respect to the direction perpendicular to the cutting face K1 is 0° (when the chisel 16 extends in the direction perpendicular to the cutting face K1), as shown in Figures 4(b) and 4(c), when the impact angle θ of the breaker 15 with respect to the direction perpendicular to the cutting face K1 is downward, and especially when the impact angle θ of the breaker 15 with respect to the direction perpendicular to the cutting face K1 is upward, the acceleration values ​​(vibration values) collected by the vibration acceleration collecting unit 2b and the sound pressure levels collected by the impact sound collecting unit 2c tend to be unstable and the sound pressure levels tend to be large.

[0033] Figure 5(a) shows vibration acceleration data when the impact angle θ of the breaker 15 relative to the perpendicular direction of the face K1 is 0°, Figure 5(b) shows vibration acceleration data when the impact angle θ of the breaker 15 relative to the perpendicular direction of the face K1 is 30° upward, and Figure 5(c) shows vibration acceleration data when the impact angle θ of the breaker 15 relative to the perpendicular direction of the face K1 is 30° downward.

[0034] In Figures 5(a), 5(b), and 5(c), "ground impact" indicates the vibration acceleration level when impacting the face K, and "spray impact" indicates the vibration acceleration level when impacting the face K on which concrete has been sprayed. Generally, the strength of a face K on which concrete has been sprayed is higher than the strength of a face K on which concrete has not been sprayed, so spray impact should result in a higher vibration acceleration level.

[0035] As shown in Figures 5(a) and 5(c), when the impact angle θ of the breaker 15 relative to the direction perpendicular to the face K1 is 0°, and when the impact angle θ of the breaker 15 relative to the direction perpendicular to the face K1 is 30° downward, the mirror blowing impact resulted in a higher vibration acceleration level in the frequency band of 1 kHz to 8 kHz.

[0036] In contrast, as shown in Figure 5(b), when the impact angle θ of the breaker 15 relative to the direction perpendicular to the face K1 is 30° upward, no significant difference was observed between the mirror blast impact and the natural ground impact. Therefore, it was found that when the impact angle θ of the breaker 15 relative to the direction perpendicular to the face K1 is 0° or 30° downward, the strength of the face K can be calculated with high accuracy, but when the impact angle θ is 30° upward, the strength of the face K cannot be calculated with high accuracy.

[0037] Taking the above trends into consideration, the strength calculation unit 5 calculates the strength of the cutting face K from the evaluation index when the impact angle θ satisfies θ1≦θ≦θ2, where θ1 is a negative real number and θ2 is a positive real number, relative to the orthogonal direction of the cutting face K1, with an upward angle being a positive angle direction and a downward angle being a negative angle direction. The absolute value of θ1 is greater than the absolute value of θ2. For example, θ1 is -30° and θ2 is 15°. In this case, the strength calculation unit 5 can calculate the strength by excluding the evaluation index when the impact angle θ is less than θ1 or greater than θ2, thereby enabling more accurate calculation of the strength.

[0038] Alternatively, the intensity calculation unit 5 may calculate an evaluation value from the evaluation index and correct the evaluation value by multiplying the evaluation value by a correction coefficient A (where A is a positive real number) that corresponds to the value of the impact angle θ. The larger the absolute value of the impact angle θ, the smaller the correction coefficient A. Specific examples of the magnitude of the correction coefficient A are described below. If θ1 is a negative real number, θ3 is a negative real number greater than θ1, θ4 is a positive real number, and θ2 is a positive real number greater than θ4, the value of the correction coefficient A when the impact angle θ satisfies θ3≦θ≦θ4 is larger than the value of the correction coefficient A when the impact angle θ satisfies θ1<θ<θ3 and the value of the correction coefficient A when the impact angle θ satisfies θ4<θ<θ2.

[0039] Furthermore, the value of the correction coefficient A when the impact angle θ satisfies θ1<θ<θ3 is greater than the value of the correction coefficient A when the impact angle θ satisfies θ4<θ<θ2. Thus, the correction coefficient A when the impact angle θ is close to 0° and the correction coefficient A when the impact angle θ is downward are greater than the correction coefficient A when the impact angle θ is upward.

[0040] Next, an example of a method for evaluating the strength of the tunnel face K by the strength calculation unit 5 will be described. Below, an example of the operation of the strength measurement software by the strength calculation unit 5, which is software installed in the information terminal 4, will be described. First, the measurement software is started up in the information terminal 4.

[0041] When the measurement software is started, a screen showing the face K in a split display is displayed on the information terminal 4, as shown in FIG. 6, for example. As an example, the screen is displayed to show the top end "1," upper left "2," upper right "3," lower left "4," and lower right "5" of the face K. Next, the location to be struck by the breaker 15 is selected from the screen. For example, on the screen, tap on any of the top end "1," upper left "2," upper right "3," lower left "4," and lower right "5."

[0042] Then, after aligning the breaker 15 horizontally with respect to the tunnel face K, the measurement button displayed on the information terminal 4 is pressed and the selected part of the tunnel face K is struck with the breaker 15. At this time, the sensor 2 collects evaluation indices. As a specific example, the vibration acceleration collecting unit 2b collects vibration acceleration levels, the impact sound collecting unit 2c collects sounds, and the breaker impact angle detecting unit 2d detects the impact angle θ.

[0043] The evaluation indexes collected by the sensor 2 are output to the information terminal 4 via the cable 3, for example, and recorded in the information terminal 4. The intensity calculation unit 5 calculates the strength of the working face K from the evaluation indexes recorded in the information terminal 4. For example, the intensity calculation unit 5 performs frequency analysis (FFT analysis, 1 / 3 octave band, as an example) on the vibration acceleration data collected by the vibration acceleration collection unit 2b, and calculates the maximum or average signal intensity in a predetermined frequency band (see FIG. 5(a)).

[0044] For example, the intensity calculation unit 5 calculates a partial overall value (POA) at this time. The POA is the sum of the squared values ​​of the amplitudes in a predetermined frequency band, and is a physical value used when monitoring the magnitude of the amplitude in a predetermined frequency band after FFT analysis. A higher POA indicates higher intensity (hardness), and a lower POA indicates lower intensity (softness).

[0045] For example, as shown in Fig. 7, an approximation formula showing the relationship between the POA and the natural ground strength (strength of the tunnel face K) is set in advance. After the strength calculation unit 5 calculates the POA as described above, the strength calculation unit 5 calculates the strength of the tunnel face K from the calculated POA and the approximation formula. For example, the calculated strength of the tunnel face K is divided into a plurality of categories (as examples, category 1, category 2, category 3, and category 4) in advance.

[0046] In this case, the strength calculation unit 5 displays the classification along with the calculated strength of the face K to evaluate the face K. For example, it shows that classification 4 is the highest strength, classification 3 is the second highest strength, classification 2 is the third highest strength, and classification 1 is the lowest strength. The operator of the backhoe 10 or the like can evaluate the face K by looking at the strength and classification of the face K calculated by the strength calculation unit 5.

[0047] Next, the effects obtained by the tunnel face evaluation device 1 according to this embodiment will be described in more detail. As shown in FIGS. 2 to 4, in the tunnel face evaluation device 1, the tunnel face K is evaluated by a backhoe 10 equipped with a base 11 and a breaker 15. The tunnel face evaluation device 1 includes a vibration acceleration collection unit 2b and a strength calculation unit 5. The vibration acceleration collection unit 2b, which is an accelerometer, collects acceleration data when the breaker 15 strikes the tunnel face K. The vibration acceleration level is then calculated from the acceleration data. The strength calculation unit 5 calculates the strength of the tunnel face K from the acceleration data collected by the vibration acceleration collection unit 2b. The strength of the tunnel face K, such as its hardness, can be determined with high accuracy from the acceleration data generated when the breaker 15 strikes the tunnel face K. Therefore, the strength of the tunnel face K can be evaluated with high accuracy by the strength calculation unit 5 calculating the strength from the acceleration data. Furthermore, the tunnel face evaluation device 1 can evaluate the strength of the tunnel face K by collecting acceleration data when the breaker 15 strikes the tunnel face K. Therefore, the condition of the tunnel face K can be easily and accurately evaluated using the breaker 15.

[0048] In this embodiment, the face evaluation device 1 includes a breaker impact angle detection unit 2d that detects the impact angle θ of the breaker 15 on the face K, and the strength calculation unit 5 calculates the strength of the face K using the acceleration and the breaker impact angle θ. The impact force on the face K depends on the impact angle θ of the breaker 15 on the face K. For example, a more appropriate impact force can be applied to the face K1 when the breaker 15 faces downward relative to the perpendicular direction of the face K1 than when the breaker 15 faces upward relative to the perpendicular direction of the face K1. Therefore, the breaker impact angle detection unit 2d detects the impact angle θ of the breaker 15, and the strength calculation unit 5 calculates the strength of the face K using the impact angle θ of the breaker 15, thereby making it possible to evaluate the condition of the face K, such as its strength, with higher accuracy.

[0049] Furthermore, in the tunnel face evaluation device 1, the impact sound collection unit 2c, which is a microphone, may collect the impact sound when the breaker 15 strikes the tunnel face K, and the breaker impact angle detection unit 2d may detect the impact angle θ of the breaker 15 on the tunnel face K. In this case, the strength calculation unit 5 calculates the strength of the tunnel face K from the sound at the time of impact collected by the microphone and the impact angle θ of the breaker 15. The strength calculation unit 5 calculates the strength of the tunnel face K from the sound at the time of impact, taking into account the impact angle θ of the breaker 15, so the strength of the tunnel face K can be calculated with high accuracy. Furthermore, the tunnel face evaluation device 1 can collect the sound when the breaker 15 strikes the tunnel face K and evaluate the strength of the tunnel face K. Therefore, the condition of the tunnel face K can be evaluated easily and with high accuracy using the breaker 15.

[0050] In this embodiment, the breaker impact angle detection unit 2d may include a mechanism for detecting the extension direction of the breaker 15 relative to the base 11 as an impact angle θ. In this case, the extension direction of the breaker 15 relative to the base 11 of the backhoe 10 is detected as the impact angle θ, so that the condition of the working face K can be evaluated with higher accuracy from the detected impact angle θ.

[0051] In this embodiment, the face evaluation device 1 may further include a face angle detection unit 2f that detects the angle of the face K1 of the face K, and the breaker impact angle detection unit 2d and the face angle detection unit 2f may detect the angle of the extension direction of the breaker 15 with respect to the orthogonal direction to the face K1 as the impact angle θ. In this case, the impact angle θ is detected from the direction of the breaker 15 with respect to the face K1 of the face K. Therefore, the condition of the face K can be evaluated with higher accuracy based on the impact angle θ detected with high accuracy.

[0052] As described above, the strength calculation unit 5 may calculate the strength of the cutting face K from the evaluation index when the impact angle θ of the breaker 15 with respect to the orthogonal direction satisfies θ1≦θ≦θ2. In this case, the strength of the cutting face K is calculated from the evaluation index when the impact angle θ of the breaker 15 with respect to the orthogonal direction of the cutting face K1 is within a certain angle range. Therefore, since it is possible to exclude evaluation indexes where the impact angle θ is outside the certain angle range, it is possible to calculate the strength of the cutting face K with higher accuracy.

[0053] As described above, the strength calculation unit 5 may calculate an evaluation value from the evaluation index and correct the evaluation value by multiplying the evaluation value by a correction coefficient A (where A is a positive real number). The correction coefficient A may be smaller as the absolute value of the impact angle θ of the breaker 15 relative to the orthogonal direction increases. In this case, the evaluation value is multiplied by a larger correction coefficient A as the absolute value of the impact angle θ of the breaker 15 relative to the orthogonal direction of the cutting face K1 decreases. Therefore, the accuracy of the evaluation value can be further improved by multiplying an evaluation value with a large absolute value of the impact angle θ relative to the orthogonal direction and low accuracy by a small correction coefficient A, and by multiplying an evaluation value with a small absolute value of the impact angle θ relative to the orthogonal direction and high accuracy by a large correction coefficient A. As a result, the condition of the cutting face, such as its strength, can be evaluated with even higher accuracy.

[0054] (Example) Next, examples of the face evaluation device 1 according to this embodiment will be described. Note that the present invention is not limited to the contents of the following examples. First, the face evaluation device 1 measured the vibration acceleration levels when three concrete specimens (hereinafter referred to as specimen 1, specimen 2, and specimen 3) with different mechanical properties were struck vertically downward with a constant pressure. In the face evaluation device 1, a vibration acceleration collecting unit 2b was installed in the breaker 15, and a sound level meter was installed in the cabin 11b to measure the sound pressure level. Each of specimens 1, 2, and 3 measured 2 m wide x 2 m deep x 1 m high. Uniaxial compression tests, impact testing, and elastic wave measurements were performed on them, and the mechanical properties shown in Table 1 below were obtained. [Table 1]

[0055] Furthermore, the vibration acceleration level and sound pressure level were measured for each of specimens 1, 2, and 3 by performing the strength evaluation method described above. Fig. 8 is a graph showing the measurement results of the vibration acceleration level, and Fig. 9 is a graph showing the measurement results of the sound pressure level. As shown in Figs. 8 and 9, it was found that the stronger the specimen 3, the stronger the signal obtained in the high-frequency band for both the vibration acceleration level and the sound pressure level. In this measurement, when the vibration acceleration level was in the frequency band of 800 Hz to 4 kHz and the sound pressure level was in the frequency band of 3 kHz to 6 kHz, the signal level changed depending on the mechanical properties of the specimen. Therefore, it was found that the mechanical properties of the specimen can be estimated by measuring the vibration acceleration or sound pressure.

[0056] Furthermore, measurements were conducted to calculate the uniaxial compressive strength of test specimen 2 while changing the impact angle θ of the breaker 15. The measurement details and results are shown in Tables 2 and 3 below. In Tables 2 and 3, the calculated values ​​of the uniaxial compressive strength of test specimen 2 are listed for Sample 1, Sample 2, Sample 3, Sample 4, and Sample 5, respectively. Table 2 shows the results of calculating the uniaxial compressive strength by correcting the acceleration collected by the vibration acceleration collecting unit 2b (evaluation value calculated from the evaluation index). Table 3 shows the results of calculating the uniaxial compressive strength by correcting the sound volume collected by the impact sound collecting unit 2c (evaluation value calculated from the evaluation index). In Table 2, the uniaxial compressive strength Y1 was calculated using the following formula (1). Y1 = (coefficient a1 × (acceleration X1 - coefficient b1)) × correction coefficient (1) In Table 3, the unconfined compressive strength Y1 was calculated from the following formula (2). Y2 = (coefficient a2 × (volume X2 - coefficient b2)) × correction coefficient (2) [Table 2] [Table 3]

[0057] As shown in Tables 2 and 3, it was found that if the correction coefficient when the impact angle θ is downward is set to be equal to or less than the correction coefficient when the impact angle θ is 0°, the correction coefficient when the impact angle θ is upward is set to be smaller than the correction coefficient when the impact angle θ is downward, and the correction coefficient is set to be larger when the impact angle θ is close to 0°, it is possible to calculate a value close to the value in Table 1 as the unconfined compressive strength of test specimen 2. It was found that by using multiple correction coefficients that differ from each other depending on the value of the impact angle θ as described above, it is possible to measure the unconfined compressive strength with high accuracy.

[0058] The above describes embodiments and examples of the cutting face evaluation device according to the present disclosure. However, the present disclosure is not limited to the above-described embodiments or examples, and can be modified as appropriate within the scope of the gist described in the claims. In other words, the configuration, function, shape, size, number, material, and arrangement of each part of the cutting face evaluation device can be modified as appropriate within the scope of the above-described gist.

[0059] For example, in the above embodiment, an example has been described in which the sensor 2 has the vibration acceleration collecting unit 2b and the impact sound collecting unit 2c. However, the sensor may have only one of the vibration acceleration collecting unit 2b and the impact sound collecting unit 2c. In other words, the face evaluation device may evaluate the face using only either acceleration or sound.

[0060] In the above-described embodiment, the face evaluation device 1 has been described in which the heavy machinery is the backhoe 10. However, the configuration of the backhoe is not limited to the backhoe 10 and can be changed as appropriate. Furthermore, the heavy machinery may be something other than a backhoe. In this way, the face evaluation device according to the present disclosure can be applied to various heavy machinery. [Explanation of symbols]

[0061] 1...face evaluation device, 2...sensor, 2b...vibration acceleration collection unit, 2c...impact sound collection unit, 2d...breaker impact angle detection unit, 2f...face angle detection unit, 3...cable, 4...information terminal, 5...strength calculation unit, 10...backhoe, 11...base, 11b...cabin, 12...boom, 13...arm, 15...breaker, 16...chisel, 17...bracket, G...ground, G1, G2, G3, G4...layer, K...face, K1...face, θ...impact angle

Claims

1. A tunnel face evaluation device that evaluates a tunnel face using heavy machinery equipped with a base and a breaker, an evaluation index collection unit that collects evaluation indexes at the time of impact of the breaker on the face; a strength calculation unit that calculates the strength of the face using the evaluation index; Equipped with the evaluation index is acceleration, and the evaluation index collection unit is an accelerometer; Further, a breaker impact angle detection unit is provided to detect an impact angle of the breaker, The strength calculation unit calculates the strength of the face using the acceleration and the impact angle of the breaker. Face evaluation device.

2. A tunnel face evaluation device that evaluates a tunnel face using heavy machinery equipped with a base and a breaker, an evaluation index collection unit that collects evaluation indexes at the time of impact of the breaker on the face; a breaker impact angle detection unit that detects an impact angle of the breaker; a strength calculation unit that calculates the strength of the face using the evaluation index at the time of impact and the impact angle of the breaker; Equipped with The evaluation index is sound, and the evaluation index collection unit is a microphone. Face evaluation device.

3. the breaker impact angle detection unit includes a mechanism that detects the extending direction of the breaker relative to the base as the impact angle. The face evaluation device according to claim 1 or 2.

4. Further, a face angle detection unit is provided to detect the angle of the face of the face, the breaker impact angle detection unit and the face angle detection unit detect, as the impact angle, an angle of the extension direction of the breaker with respect to a direction orthogonal to the face; The face evaluation device according to claim 3.

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