JP2012173064A - Rock quality evaluation method and rock quality evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rock quality evaluation method and a rock quality evaluation device capable of being easily implemented at a quarry.SOLUTION: A rock quality evaluation method includes: a water absorption rate correlation preparation step (S101) which makes a calculation device store a correlation between an elastic modulus and a water absorption rate of a rock material as a water absorption rate correlation; a striking exploration step (S105) which makes the calculation device calculate the elastic modulus of the rock based on acceleration data obtained through an acceleration sensor when striking the rock with a metal hammer having the acceleration sensor and a spherical striking surface; a water absorption rate estimation step which makes the calculation device estimate the water absorption rate of the rock based on the calculated elastic modulus and the water absorption correlation; and a usability determination step (S109) which determines availability of the rock for a use of the rock based on comparison of a water absorption rate estimate obtained by the water absorption estimation step with a water absorption rate reference value preliminarily set in accordance with the use of the rock.

Description

  The present invention relates to a rock quality evaluation method and a quality evaluation apparatus.

  Traditionally, natural rocks have been used for various purposes in construction projects. For example, aggregates used for concrete are manufactured so as to satisfy the standards defined in JIS and the like using rocks collected at a quarry as raw materials. In addition, for example, in the construction of a rock fill dam, durability is required for the rock material at the outer periphery of the dam, and therefore, high quality rocks collected from the rough rocks near the construction site are used as the rock material. Since such rocks are derived from nature, in reality, various rock types are often mixed. Therefore, in order to efficiently collect rocks suitable for the purpose, it is necessary to confirm the rock type by a preliminary survey, and it is necessary to frequently confirm the rock type even during the collection. As techniques for evaluating the quality of rocks, for example, those described in Non-Patent Documents 1 and 2 below are known.

JP 2004-150946 A

Dam Technology Center, “Construction of Multipurpose Dam”, 2005 edition, Volume 5, Design II Japan Dam Association, “Construction of Phil Dam”, pp.239, Table 3.5.1

  The boring survey described in pp. 87 of Non-Patent Document 1 and Table 25-6 is conducted as a preliminary survey of Mt. The boring survey is carried out on a 50-100 m grid with respect to Harayama, and only point information can be obtained for the vast Haraishi. In addition, as a method of judging the rock type during rock collection, according to the judgment criteria described in pp. 116 of Non-Patent Document 1, Table 15-23 and Non-Patent Document 2, the rock is visually judged and used for rocks. Based on the hammering sound and knowledge of the surrounding terrain and geological composition, the geological engineer determines the rock type during rock collection. However, this method requires a skilled geological engineer and may cause individual differences in judgment. In addition, as described in pp. 119 of Non-Patent Document 1 and Tables 15-26, rocks that can be applied to rockfill dam rocks and concrete aggregates are generally defined by their density or water absorption rate. It is. There is JIS A 1100 “Coarse Aggregate Density and Water Absorption Test” as a method for measuring the density and water absorption rate, but this test takes a certain amount of time. Such operations are not possible.

  In view of such a problem, an object of the present invention is to provide a rock quality evaluation method that can be easily executed at a sampling site and a quality evaluation apparatus that executes the method.

  The present inventors have found that the water absorption rate and density of a rock have a correlation with the elastic modulus of the rock, and the elastic modulus is measured more easily in the field than the direct measurement of the water absorption rate and density. The present invention has been completed by paying attention to the existence of.

  The rock quality evaluation method of the present invention is a natural rock quality evaluation method, wherein the rock material obtained by the predetermined elastic modulus measurement method and the rock absorption coefficient obtained by the predetermined water absorption measurement method are used. The water absorption coefficient correlation preparation step for storing the correlation between the elastic coefficient of the rock material and the water absorption coefficient obtained based on the material water absorption coefficient in the arithmetic unit as the water absorption coefficient correlation, and the impact of the acceleration sensor and the spherical shape Hitting rocks with a metal hammer having a surface, and a ball hitting exploration process in which an arithmetic unit calculates the elastic modulus of the rock based on acceleration data obtained by an acceleration sensor; and an elastic coefficient calculated in the ball hitting exploration process; The water absorption rate correlation stored in the water absorption rate correlation preparation step, the water absorption rate estimation step for causing the arithmetic unit to estimate the water absorption rate of the rock based on the water absorption rate correlation, the water absorption rate estimation value obtained in the water absorption rate estimation step, and the rock Based on a comparison of the preset water absorption reference value depending on the application, characterized in that it comprises, and the usability determining step of determining the availability of the rock for applications.

  In this quality evaluation method, the correlation between the elastic coefficient of the rock material and the water absorption rate (water absorption rate correlation) is stored in the arithmetic unit. Then, the arithmetic device calculates the elastic coefficient of the rock based on the acceleration data when the rock is hit with a hammer. Further, the computing device obtains the water absorption rate estimated value based on the elastic coefficient and the water absorption rate correlation, and determines whether or not the rock can be used by comparing the water absorption rate estimated value with the water absorption rate reference value. it can. Therefore, according to this quality evaluation method, it is possible to determine on the spot whether or not the rock can be used at a rock collection site by a simple operation of hitting the rock with a hammer.

  Alternatively, the rock quality evaluation method of the present invention is a rock that is obtained based on the elastic modulus of the rock material obtained by a predetermined elastic modulus measurement method and the density of the rock material obtained by a predetermined density measurement method. The correlation between the elastic modulus and density of the material is stored as a density correlation in the computing device, the density correlation preparation step, the elastic coefficient calculated in the hit ball exploration step, and the density correlation stored in the density correlation preparation step A density estimation step for causing the arithmetic unit to estimate the density of the rock based on the relationship, and in the usability determination step, the density estimation value obtained in the density estimation step and a preset value according to the use of the rock Further, based on the comparison with the density reference value, it is possible to determine whether or not the rock can be used for the application.

  According to this configuration, the correlation (density correlation) between the elastic modulus and density of the rock material is also stored in the arithmetic unit. Then, the computing device can determine the density estimation value based on the elastic modulus and the density correlation, and can determine whether or not the rock can be used based on the comparison between the density estimation value and the density reference value. . Therefore, according to this quality evaluation method, it is possible to determine whether or not the rock can be used based on not only the water absorption rate of rock but also the density.

  The rock quality evaluation method of the present invention is a natural rock quality evaluation method, wherein the rock material obtained by a predetermined elastic modulus measurement method and the rock material obtained by a predetermined density measurement method A density correlation preparation step for storing the correlation between the elastic modulus of the rock material obtained based on the density of the rock material and the density in the arithmetic device as the density correlation, and a metal having an acceleration sensor and a spherical striking surface A striking ball exploration process in which a rock hammer is struck and the computing device calculates the elastic modulus of the rock based on the acceleration data obtained by the acceleration sensor, the elastic modulus calculated in the striking ball exploration process, and the density correlation preparation process Based on the density correlation stored in step 1, the density estimation step for causing the arithmetic unit to estimate the density of the rock based on the density correlation, the density estimation value obtained in the density estimation step, and preset according to the use of the rock The Based on the comparison between the density reference value, characterized in that it comprises, and the usability determining step of determining the availability of the rock for applications.

  In this quality evaluation method, the correlation (density correlation) between the elastic modulus and density of the rock material is stored in the arithmetic unit. Then, the arithmetic device calculates the elastic coefficient of the rock based on the acceleration data when the rock is hit with a hammer. Furthermore, it is possible to determine whether or not the rock can be used by calculating a density estimated value based on the elastic modulus and the density correlation, and comparing the density estimated value with the density reference value. Therefore, according to this quality evaluation method, it is possible to determine on the spot whether or not the rock can be used at a rock collection site by a simple operation of hitting the rock with a hammer.

  Further, the predetermined elastic modulus measurement method in the correlation preparation step may be a method in which the rock material is hit with a hammer and the elastic coefficient of the rock material is calculated with an arithmetic device based on the acceleration data. According to this method, it is possible to accurately obtain the water absorption rate estimated value or the density estimated value from the elastic coefficient of the rock obtained by hammering.

  Further, as a specific configuration, the hammer in the hit ball searching step may have a spherical hitting portion including a hitting surface.

  In the hit ball exploration step, the rock particle size may be 10 cm or more, and the hammer mass may be less than 3 kg. If it is a small rock having a particle size of less than 10 cm, the entire rock vibrates due to the impact of hammering, and good acceleration data that accurately reflects the elastic modulus of the rock cannot be acquired. In addition, if the mass of the hammer is less than 3 kg, it is easy to carry and handle and can be easily measured at the rock sampling site.

  The quality evaluation apparatus of the present invention is a quality evaluation apparatus for naturally occurring rocks, which is obtained by an acceleration sensor when a rock hammer is hit with a metal hammer having an acceleration sensor and a spherical hitting surface. An arithmetic device that processes acceleration data, and the arithmetic device includes an elastic coefficient of the rock material obtained by a predetermined elastic modulus measurement method, a water absorption rate of the rock material obtained by a predetermined water absorption rate measurement method, and The water absorption coefficient correlation storage means for storing the correlation between the elastic modulus of the rock material and the water absorption obtained as a function of the water absorption coefficient, and the elastic coefficient of the rock based on the acceleration data obtained by the acceleration sensor The water absorption rate of the rock is estimated based on the elastic coefficient calculation means, the elastic coefficient calculated by the elastic coefficient calculation means, and the water absorption correlation stored in the water absorption correlation storage means Based on the comparison between the water rate estimation means, the water absorption rate estimated value obtained by the water absorption rate estimation means, and the water absorption rate reference value set in advance according to the use of the rock, it is determined whether or not the rock can be used for the usage. And a usability determining unit.

  In this quality evaluation apparatus, the correlation between the elastic coefficient of the rock material and the water absorption rate (water absorption rate correlation) is stored in the water absorption rate correlation storage means of the arithmetic unit. Then, the elastic coefficient calculating means of the arithmetic unit calculates the elastic coefficient of the rock based on the acceleration data when the rock is hit with a hammer. Further, the water absorption rate estimation means obtains the water absorption rate estimated value based on the elastic coefficient and the water absorption rate correlation, and the usability determination means compares the water absorption rate estimated value with the water absorption rate reference value, thereby It can be determined whether or not it can be used. Therefore, according to this quality evaluation apparatus, it is possible to determine on the spot whether or not the rock can be used at a rock collection site by a simple operation of hitting the rock with a hammer.

  Further, the arithmetic unit calculates the elastic modulus and density of the rock material obtained based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the density of the rock material obtained by the predetermined density measurement method. Of the rock based on the density correlation storage means for storing the correlation as a density correlation, the elastic coefficient calculated by the elastic coefficient calculation means, and the density correlation stored in the density correlation storage means Density estimation means for estimating density, and the usability determination means also compares the density estimation value obtained by the density estimation means with a density reference value set in advance according to the use of the rock. Furthermore, it is good also as determining the availability of the rock with respect to a use.

  According to this configuration, the correlation (density correlation) between the elastic modulus and density of the rock material is also stored in the arithmetic unit. Then, the density estimating means obtains a density estimated value based on the elastic coefficient and the density correlation, and the usability determining means is further based on the comparison between the density estimated value and the density reference value to determine whether or not the rock is usable. Can be determined. Therefore, according to this quality evaluation apparatus, it is possible to determine whether or not it is usable based on not only the water absorption rate of rock but also the density.

  The quality evaluation apparatus of the present invention is a quality evaluation apparatus for naturally occurring rocks, which is obtained by an acceleration sensor when a rock hammer is hit with a metal hammer having an acceleration sensor and a spherical hitting surface. An arithmetic device that processes acceleration data, and the arithmetic device is based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measuring method and the density of the rock material obtained by the predetermined density measuring method. Density correlation storage means for storing the correlation between the elastic modulus and density of the rock material obtained as a density correlation, and an elastic coefficient calculation means for calculating the elastic coefficient of the rock based on the acceleration data obtained by the acceleration sensor Density estimation means for estimating the density of the rock based on the elastic coefficient calculated by the elastic coefficient calculation means and the density correlation stored in the density correlation storage means; Use determination means for determining whether or not the rock can be used for the use based on a comparison between the density estimated value obtained by the degree estimation means and a density reference value set in advance according to the use of the rock. It is characterized by.

  In this quality evaluation apparatus, the correlation (density correlation) between the elastic modulus and density of the rock material is stored in the density correlation storage means of the arithmetic unit. Then, the elastic coefficient calculating means of the arithmetic unit calculates the elastic coefficient of the rock based on the acceleration data when the rock is hit with a hammer. Further, the density estimating means obtains a density estimated value based on the elastic coefficient and the density correlation, and the usability judging means compares the density estimated value with the density reference value, thereby judging whether or not the rock can be used. It can be carried out. Therefore, according to this quality evaluation apparatus, it is possible to determine on the spot whether or not the rock can be used at a rock collection site by a simple operation of hitting the rock with a hammer.

  According to the rock quality evaluation method and the quality evaluation apparatus of the present invention, the rock quality can be easily evaluated at the sampling site.

It is a figure which shows the structure of 1st Embodiment of the quality evaluation apparatus of this invention. It is a figure which shows the structure of the computer of the quality evaluation apparatus of 1st Embodiment. It is an example of the graph which shows the correlation with the elastic modulus of a rock, and a water absorption. It is a flowchart which shows 1st Embodiment of the quality evaluation method of this invention. It is a graph which shows the result of the test which the present inventors conducted. It is a flowchart which shows an example of the rock sampling construction using the quality evaluation method of this invention. It is a figure which shows the structure of the computer of the quality evaluation apparatus of 2nd Embodiment. It is an example of the graph which shows the correlation with the elastic modulus and absolute dry density of a rock. It is a flowchart which shows 2nd Embodiment of the quality evaluation method of this invention. It is a figure which shows the structure of the computer of the quality evaluation apparatus of 3rd Embodiment. It is a flowchart which shows 3rd Embodiment of the quality evaluation method of this invention.

  Hereinafter, preferred embodiments of a rock quality evaluation method and a quality evaluation apparatus according to the present invention will be described in detail.

(First embodiment)
FIG. 1 shows a quality evaluation apparatus according to this embodiment. The quality evaluation apparatus 1 is an apparatus for performing quality evaluation of the naturally derived rock R. Naturally-occurring rocks include rocks produced by blasting from the bedrock of Mt. Since this type of rock is used as a rock material for rockfill dams or aggregates for concrete, for example, the quality evaluation device 1 evaluates whether or not a predetermined quality is satisfied and determines whether or not it can be used. The

  As shown in the figure, the quality evaluation apparatus 1 includes a metal hammer 11, a charge amplifier 13, a DC power supply 15 for the charge amplifier 13, a terminal panel 19, an AD converter 21, and a computer (arithmetic unit). 23, a digital camera 25, and a GPS device 27.

  The hammer 11 includes a rod-shaped handle portion 11c for a user to hold, a spherical hitting portion 11a attached to the tip of the handle portion 11c, a uniaxial acceleration sensor 11b attached above the hitting portion 11a, have. The hammer 11 is for hitting the rock R which is a quality evaluation target. The user of the quality evaluation apparatus 1 grips the handle portion 11c and causes the hitting portion 11a to collide with the rock R. The lower part of the surface of the hitting part 11a constitutes a spherical hitting face 11d that actually collides with rocks.

  The mass of the hammer 11 is preferably less than 3 kg from the viewpoint of facilitating carrying and handling at the rock collection site (raw stone mountain). The diameter of the hitting part 11a is, for example, about 5 cm. In order to execute the hit ball exploration method to be described later, it is not essential that the hitting portion 11a has a spherical shape, and at least the hitting surface 11d may have a spherical shape.

  The acceleration sensor 11b measures the acceleration in the collision direction between the striking surface 11d and the rock R. When the user hits the rock R with the hammer 11, the acceleration sensor 11b detects an impact waveform generated by a collision between the hitting surface 11d and the rock as an acceleration waveform. The detected acceleration waveform is transmitted as an acceleration signal to the computer 23 via the charge amplifier 13, the terminal panel 19, and the AD converter 21. The charge amplifier 13 amplifies the acceleration signal from the acceleration sensor 11b, the terminal panel 19 removes a noise component included in the amplified signal, and the AD converter 21 functions to AD-convert the signal after noise removal. Have

  As the computer 23, a commercially available personal computer storing a predetermined quality evaluation program can be used. By executing the quality evaluation program, the computer 23 performs a calculation based on the acceleration signal obtained from the acceleration sensor 11b, and outputs a rock evaluation result. As the computer 23, it is preferable to use a laptop computer because it is preferably small and lightweight from the viewpoint of facilitating carrying and handling at a rock collection site.

  A commercially available digital camera can be used as the digital camera 25. When the user takes an appearance photograph of the rock R with the digital camera 25, the appearance photograph data of the rock R and the quality evaluation result can be associated and recorded in the computer 23. A commercially available GPS device can be used as the GPS device 27. The GPS device 27 calculates the current position of the quality evaluation device 1 based on the radio wave received from the GPS satellite, and transmits the current position information to the computer 23. By performing the quality evaluation work of the rock R at the rock R sampling position, the rock R sampling position and the quality evaluation result can be correlated and recorded in the computer 23, and the rock quality evaluation result is managed for each sampling position. can do.

  As shown in FIG. 2, the computer 23 includes an information storage unit 30 a, a calculation unit 40 a, an information storage unit 50, and a display 60. The information storage unit 30a stores a water absorption rate correlation 31a and a water absorption rate reference value 33a. The water absorption rate correlation 31a is information indicating the correlation between the elastic coefficient of the rock and the water absorption rate, and is represented by, for example, a curve graph as shown in FIG. The water absorption rate correlation 31a is acquired by the water absorption rate correlation preparation step described later, and is stored in the information storage unit 30a in advance. The correlation between the elastic modulus of the rock and the water absorption rate is represented by a curve as shown in FIG.

  The water absorption reference value 33a is information indicating an upper limit value of the water absorption for the rock R to be used for a desired application. For example, when the rock R is used as a rock material for a rockfill dam, the water absorption rate of the rock R is required to be 3.0% or less, so that “water absorption standard value = 3.0%” Information is stored in the information storage unit 30a. The water absorption reference value 33a is set based on, for example, a special specification or construction plan, and is input in advance by a key operation of the computer 23 by the user. The information storage unit 30a and the information storage unit 50 are storage areas of a storage device built in the computer 23, for example.

  The calculation unit 40a includes an elastic coefficient calculation unit 41, a water absorption rate estimation unit 43a, and a usability determination unit 45a. The elastic coefficient calculation unit 41, the water absorption rate estimation unit 43a, and the usability determination unit 45a read a predetermined quality evaluation program on hardware such as the CPU and RAM of the computer 23, thereby controlling the CPU. It is a component realized by software by operating a communication module, an input device, an output device, and the like, and reading and writing data in a RAM and an auxiliary storage device.

The elastic coefficient calculation unit 41 calculates the elastic coefficient of the rock R using Hertz elastic contact theory based on the acceleration signal obtained from the acceleration sensor 11b. According to Hertz's elastic contact theory, the contact time between the sphere and the elastic plane when the sphere collides with the elastic surface is expressed by the following equation (1).

However,
E ₁ : Elastic coefficient of the sphere μ ₁ : Poisson's ratio of the sphere R: Radius of the sphere M: Mass of the sphere E ₂ : Elastic coefficient of the elastic body μ ₂ : Poisson's ratio of the elastic body V ₀ : Collision speed.

Patent Document 1 discloses that Hertz's elastic contact theory as described above is used for measuring the rigidity of a concrete structure. In this embodiment, when measuring the elastic coefficient of the rock R, Hertz's elastic contact theory is applied. That is, in this embodiment, in the Hertz elastic contact theory, the hitting portion 11a of the hammer 11 is applied to the sphere, and the rock R is applied to the elastic body. In this case, E ₁ , μ ₁ , R, and M are known in the equation (1). As the Poisson's ratio μ ₂ of the rock R, a value of 0.2 may be used as the Poisson's ratio of a general rock. Furthermore, T _c and V ₀ can be calculated from the impact waveform represented by the acceleration signal. Therefore, as long obtained acceleration signal, may be based on the equation (1) to calculate the elastic modulus E ₂ of the rock R is unknown amount.

Water ratio estimating unit 43a on the basis of the modulus of elasticity E ₂ of the rock R obtained by the elastic coefficient calculation unit 41, estimates the water absorption of the rock R. That is, the water absorption rate estimation unit 43a, reads the stored water absorption correlation 31a in the information storage unit 30a (FIG. 3), the value of water absorption corresponding to the value of the modulus of elasticity E _2, the water absorption of the rock R Obtained as an estimated value.

  The availability determination unit 45a compares the water absorption rate estimated value obtained by the water absorption rate estimation unit 43a with the water absorption rate reference value 33a read from the information storage unit 30a. When the estimated water absorption rate is equal to or less than the water absorption reference value 33a, it is determined that the rock R can be used for a predetermined application (for example, an application as a rock material for a rockfill dam). On the other hand, when the water absorption rate estimated value is larger than the water absorption rate reference value 33a, it is determined that the rock R cannot be used for a predetermined application. Thereafter, the usability determination unit 45a displays the determination result (whether the rock R can be used) on the display 60 of the computer 23 together with the estimated water absorption rate, for example. Furthermore, the usability determining unit 45a associates the availability of the rock R, the estimated water absorption rate, the current position information obtained from the GPS device 27, and the appearance photograph data of the rock R obtained from the digital camera 25. To be stored in the information storage unit 50.

  Furthermore, the usability determination unit 45a compares the estimated water absorption rate of the rock according to the previous evaluation accumulated in the information storage unit 50 with the estimated water absorption rate of the rock R according to the current evaluation, The presence or absence of rock quality fluctuations may be determined.

  Next, a rock quality evaluation method performed using the above-described quality evaluation apparatus 1 will be described with reference to FIG.

[Water absorption rate correlation preparation process]
A water absorption correlation indicating a correlation between the elastic coefficient of the rock and the water absorption is stored in the information storage unit 30a of the computer 23 (S101). The water absorption correlation is based on the measurement of the elastic modulus and water absorption of rocks at various sites (various rock types), and the correlation between the elastic coefficient and the water absorption is obtained. The obtained correlation.

  The water absorption correlation is obtained by the following procedure. First, a rock sample (rock material) is collected on site. In this case, a rock sample having a particle size of 15 cm or more is selected. “The particle size is 15 cm or more” means that the rock does not pass through a sieve having a mesh size of 15 cm. In the following description, the same definition is used when the term “particle size” is used. Subsequently, the elastic coefficient is calculated by hitting the collected rock sample by the hitting ball exploration method described later. On the other hand, the water absorption rate of the collected rock is measured by the test of JIS A 1100. Then, the relationship between the calculated elastic modulus and the measured water absorption is plotted. By performing the above for a large number of rock samples, the correlation between the elastic modulus of the rock and the water absorption is obtained.

  Note that a rock sample may be collected at a rock collection site where the rock is actually to be collected, a water absorption correlation may be obtained based on the rock sample, and stored in the information storage unit 30a of the computer 23. In this case, it is possible to acquire a water absorption correlation specific to the sampling site where the rock is to be collected. In addition, the water absorption rate correlation preparation step does not need to be performed at the collection site, and may be performed by bringing a rock sample into the room.

[Hitball exploration process]
First, the rock R subject to quality evaluation is selected and collected at the rock collection site (S103). In this case, a rock R having a particle diameter of 15 cm or more is selected. Next, the elastic modulus of the rock R is calculated by the ball hitting method. Specifically, the user strikes the selected rock R with the striking surface 11 d of the hammer 11. The acceleration generated in the hammer 11 at the time of impact is detected by the acceleration sensor 11b, and the acceleration signal is input to the computer 23 and input to the elastic coefficient calculation unit 41 of the calculation unit 41a. Then, the elastic coefficient calculation unit 41 calculates the elastic coefficient of the rock R from the above equation (1) based on the acceleration signal (S105).

[Water absorption rate estimation process]
Subsequently, the water absorption rate estimation unit 43a estimates the water absorption rate of the rock R based on the elastic coefficient calculation value obtained by the hitting ball exploration step and the water absorption rate correlation 31a. Specifically, the water absorption rate estimation unit 43a reads the water absorption rate correlation 31a from the information storage unit 30a, and obtains the water absorption rate value corresponding to the calculated elastic coefficient as the water absorption rate estimation value of the rock R (S107). ).

[Usability determination process]
Subsequently, the usability determination unit 45a compares the estimated water absorption rate with the water absorption reference value 33a to determine the availability of rock. Specifically, the usability determination unit 45a reads the water absorption rate reference value 33a from the information storage unit 30a, and compares the water absorption rate estimated value with the water absorption rate reference value (S109). When the water absorption estimated value is less than the water absorption reference value, it is determined that the rock R is usable (S111). When the water absorption estimated value is larger than the water absorption reference value, the rock R is not usable. Determine (S113). Thereafter, the usability determination unit 45a displays the determination result (whether the rock R can be used) on the display 60 of the computer 23 together with the estimated water absorption rate, for example.

[Appearance photo acquisition process]
Subsequently, the user takes an appearance photograph of the rock R using the digital camera 25. The obtained appearance photograph data is transmitted from the digital camera 25 to the computer 23 (S121). The appearance photograph acquisition process may be performed before the hit ball exploration process.

[Current location acquisition process]
Subsequently, the GPS device 27 calculates the current position of the quality evaluation device 1 based on the radio wave received from the GPS satellite, and transmits the current position information to the computer 23 (S123). In addition, you may perform a present location acquisition process before a hit ball search process.

[Data recording process]
Subsequently, the usability determination unit 45a determines whether or not the rock R can be used, the estimated water absorption rate, the current position information obtained from the GPS device 27, and the external photograph data of the rock R obtained from the digital camera 25. The information is accumulated in the information accumulation unit 50 (S125). Thereafter, when the quality evaluation of the rock is continued (Yes in S127), the process returns to S103, and in other cases (No in S127), the process ends.

  According to the quality evaluation method and the quality evaluation apparatus described above, the quality evaluation of the rock R can be performed by a simple operation of hitting the rock R with the hammer 11. Therefore, one quality evaluation can be performed in a short time of about 30 seconds, for example, and it becomes possible to determine whether or not the rock R can be used on the spot at the site where the rock R is collected. Therefore, it is possible to frequently check the quality of the collected rock. In addition, it is possible to collect a lot of data and perform statistical processing, thereby improving the accuracy of evaluation. In addition, the influence of the skill level of the user on the accuracy of evaluation is small. In addition, since the mass of the hammer 11 is less than 3 kg, the hammer 11 can be easily carried and handled, and measurement can be easily performed at the sampling site. As a result of the above, it is possible to evaluate rocks quickly, and the development of Mt.

  Moreover, in the hit ball exploration process, the particle size of the rock R is set to 15 cm or more. If the rock R is a small rock with a particle size of less than 15 cm, the entire rock vibrates due to the impact of hammering and an accurate acceleration signal cannot be obtained, but the rock R has a particle size of 15 cm or more. Therefore, it is possible to suppress the vibration of the entire rock due to the rocks and to obtain good acceleration data that accurately reflects the elastic coefficient of the rock. The particle diameter of the rock R is more preferably 30 cm or more.

  As another method for measuring the deformation characteristics of rocks relatively easily at the site, the so-called Rock Schmidt Hammer method (JGS 3411: Geotechnical Society standard) can be applied. The inventors of the present invention conducted a test comparing the method of obtaining the elastic modulus of rock in the hitting ball exploration process in this embodiment with the Rockschmitt hammer method. Since the Rockschmitt hammer method is a known method, detailed description thereof is omitted.

Three types of rocks with almost the same material and different sizes were prepared as specimens. A specimen having a size “large” has a particle diameter of 30 cm or more, a specimen having a size “medium” has a particle diameter of 15 cm or more and less than 30 cm, and a specimen having a size “small” has a particle diameter of 10 cm. More than 15 cm. For each of the three types of specimens, the static elastic modulus was measured by the Rockschmitt hammer method, and the elastic modulus was measured by the hitting ball exploration method in this embodiment. The diameter of the hitting portion 11a of the hammer 11 in the hit ball exploration method was 5 cm. The measurement results are shown in Table 1 together with the number of samples, standard deviation and coefficient of variation. Moreover, about the average value of a measured value, it has shown also as a graph of FIG.

  As can be seen from FIG. 5, in the Rockschmitt hammer method, the measured value is likely to vary depending on the size of the specimen. In other words, the three specimens of the same material are supposed to have the same deformation characteristics, but according to the Rockschmitt hammer method, the measured value of the static elastic modulus increases as the size of the specimen increases. Tended to be. On the other hand, according to the hit ball exploration method in the present embodiment, the measurement values of substantially the same elastic modulus are obtained for the specimen having the size “large” and the specimen having the size “medium”. Therefore, it has been found that the hitting ball exploration method in this embodiment is superior to the Rockschmitt hammer method in that the measurement value of the elastic modulus is not easily affected by the rock size.

  The Rockschmitt hammer method is originally an investigation / test method for rocks, and is not intended for rocks generated by blasting and the like that are targeted by the hit ball exploration method of this embodiment. Therefore, even if the Rock Schmidt Hammer method is used for rocks generated by blasting, etc., it is considered that the reliability of the evaluation result is low because it is not a usage method defined by the standard. In addition, the Rockschmitt hammer method stipulates that the rock surface having a size of 15 to 50 cm square is used as the measurement surface. not exist. Further, in the Rockschmitt hammer method, the unevenness of the measurement point is set to 1 mm or less, and when this is not satisfied, it is specified that the measurement point is smoothed with a grinder or a grindstone. However, in rocks generated by blasting and the like, there are hardly any irregularities within 1 mm, and it takes time to smooth the measurement points, so in practice it is difficult to evaluate rocks quickly.

  Further, the Rockschmitt hammer method stipulates that the plunger that is the striking portion is kept perpendicular to the measurement surface. However, at the rock collection site, it is difficult to keep the plunger vertical because the scaffold is not necessarily horizontal. The test standard JGS 3411 (Table-3.4.1) describes how to correct the hammer rebound according to the striking direction. This means that the hammer striking direction is downward (-90 degrees) and the horizontal direction (0 This is a correction method in the case of (degree) or upward (+90 degrees), and it is assumed that the plunger is perpendicular to the measurement surface. For the above reasons, it is difficult to apply the Rockschmitt hammer method to rocks generated by blasting.

  In addition, in the hit ball exploration method, it was impossible to measure the elastic modulus of the test piece of “small” size. Therefore, it was confirmed that the particle size of the rock R targeted by the quality evaluation method of the present embodiment needs to be 15 cm or more, and more preferably 30 cm or more.

  Note that the appearance photograph acquisition step may be omitted, and the digital camera 25 of the quality evaluation apparatus 1 may be omitted. Further, the current location acquisition step may be omitted, and the GPS device 27 of the quality evaluation device 1 may be omitted.

  Subsequently, as an example of the use of the above-described quality evaluation method, a sampling work for sampling a rock that will be a rock material of a rockfill dam from a raw stone mountain will be described with reference to FIG.

  First, the above-mentioned water absorption rate correlation preparation step is executed indoors or at the collection site for a rock sample collected from a mine ore by blasting or the like (S151). Subsequently, representative rocks having a particle size of 15 cm or more are selected as rocks for quality evaluation from the raw stone mountain (S153), and the use of the rocks as the rock material is determined using the above-described quality evaluation method (S155). ). It is preferable that five or more rocks are collected from the same sampling position and that the evaluation for the same rock is performed five or more times. If it is determined that the rock cannot be used, the rock is discarded (S157), the rock collecting position is changed (S159), and the process returns to S153.

  If it is determined in S155 that the rock can be used, the rock sampling work is executed at the sampling position (S161). The collection work is continued until the planned quantity of rock is collected (S163). During the continuation of the sampling work, when the predetermined quality confirmation quantity based on the specification or construction plan is reached (S167), the process returns to S153 and the rock quality is evaluated. In addition, when the rock type or formation of the collected rock is changed or the rock is changed (S169), the rock quality is evaluated again by returning to the process of S153. . The above is repeated, and when the planned number of rocks are collected (Yes in S163), the collection work is finished (S165).

(Second Embodiment)
Next, a rock quality evaluation method and quality evaluation apparatus according to a second embodiment of the present invention will be described with reference to FIGS. The equipment configuration of the evaluation apparatus of this embodiment is the same as that of the first embodiment (FIG. 1). In the present embodiment, the processing in the computer 23 is different from that in the first embodiment. Accordingly, the information stored in the information storage unit 30b of the computer 23 and the configuration of the calculation unit 40b are different from those in the first embodiment. Is different. In the present embodiment, the same or equivalent components and processes as those in the first embodiment are denoted by the same reference numerals in the drawings, and redundant description is omitted.

  As shown in FIG. 7, the information storage unit 30b stores a density correlation 31b and a density reference value 33b. The density correlation 31b is information indicating the correlation between the elastic modulus of rock and the absolute dry density (hereinafter simply referred to as “density”), and is represented by a curve graph as shown in FIG. 8, for example. The density correlation 31b is acquired by a density correlation preparation process described later, and is stored in the information storage unit 30b in advance. The correlation between the elastic modulus and density of rock is represented by a curve as shown in FIG.

The density reference value 33b is information indicating a lower limit value of the density for allowing the rock R to be used for a desired application. For example, when the rock R is used as a rock material for a rockfill dam, the density of the rock R is required to be 2.3 t / m ³ or more, so “density standard value = 2.3 t / m ³ ”. Is stored in the information storage unit 30b. The density reference value 33b is set based on, for example, a specification document or a construction plan, and is input in advance by a key operation of the computer 23 by the user. The information storage unit 30b and the information storage unit 50 are storage areas of a storage device built in the computer 23, for example.

  The calculation unit 40b includes an elastic coefficient calculation unit 41, a density estimation unit 43b, and a usability determination unit 45b. The elastic modulus calculation unit 41, the density estimation unit 43b, and the usability determination unit 45b communicate under the control of the CPU by reading a predetermined quality evaluation program on the hardware of the computer 23 such as the CPU and RAM. It is a component realized by software by operating a module, an input device, an output device, and the like, and reading and writing data in a RAM and an auxiliary storage device.

  The function of the elastic modulus calculation unit 41 is as described in the first embodiment.

Density estimation unit 43b, based on the elastic modulus E ₂ of the rock R obtained by the elastic coefficient calculation unit 41 estimates the density of the rock R. That is, density estimation unit 43b reads the stored density correlation 31b in the information storage unit 30b (FIG. 8), the value of the density corresponding to the value of the modulus of elasticity E _2, calculated as density estimates rock R .

  The usability determination unit 45b compares the density estimation value obtained by the density estimation unit 43b with the density reference value 33b read from the information storage unit 30b. When the estimated density value is equal to or higher than the density reference value 33b, it is determined that the rock R can be used for a predetermined application (for example, an application as a rock material for a rockfill dam). On the other hand, when the density estimated value is smaller than the density reference value 33b, it is determined that the rock R cannot be used for a predetermined application. Thereafter, the usability determination unit 45b displays the determination result (whether or not the rock R can be used) on the display 60 of the computer 23 together with the density estimation value, for example. Further, the usability determination unit 45b associates the availability of the rock R, the density estimation value, the current position information obtained from the GPS device 27, and the appearance photograph data of the rock R obtained from the digital camera 25. The information is stored in the information storage unit 50.

  Furthermore, the usability determination unit 45b compares the estimated density of the rock related to the previous evaluation accumulated in the information storage unit 50 with the estimated density of the rock R related to the current evaluation, thereby comparing the density of the rock. You may determine the presence or absence of quality fluctuation.

  Next, the quality evaluation method of the present embodiment performed using the above-described evaluation apparatus will be described with reference to FIG.

[Density correlation preparation process]
A density correlation indicating a correlation between the elastic modulus and density of the rock is stored in the information storage unit 30b of the computer 23 (S201). The density correlation is the correlation obtained by measuring the elastic modulus of the rock and measuring the density at various sites (various rock types) to obtain the correlation between the elastic modulus and the density, and combining these past data. It is a relationship.

  The density correlation is obtained by the following procedure. First, a rock sample (rock material) is collected at a rock collection site. In this case, a rock sample having a particle size of 15 cm or more is selected. Subsequently, the elastic coefficient is calculated by hitting the collected rock sample by the hitting ball exploration method described later. On the other hand, the density of the collected rock is measured by the test of JIS A 1100. Then, the relationship between the calculated elastic modulus and the measured density is plotted. By performing the above for a large number of rock samples, the correlation between the elastic modulus and density of the rock at the sampling site is obtained.

  Note that a rock sample may be collected at a rock collection site where the rock is actually to be collected, a density correlation may be obtained based on the rock sample, and stored in the information storage unit 30b of the computer 23. In this case, a density correlation peculiar to the sampling site where the rock is to be collected can be acquired. The density correlation preparation step does not have to be performed at the sampling site, and a rock sample may be brought into the room.

[Hitball exploration process]
Subsequently, a hit ball exploration process is performed (S103, S105). Details of the hit ball exploration process are as described in the first embodiment.

[Density estimation process]
Subsequently, the density estimation unit 43b estimates the density of the rock R based on the calculated elastic coefficient obtained in the hit ball exploration process and the density correlation 31b. Specifically, the density estimation unit 43b reads the density correlation 31b from the information storage unit 30b, and obtains the density value corresponding to the calculated elastic coefficient as the density estimation value of the rock R (S207).

[Usability determination process]
Subsequently, the usability determination unit 45b compares the estimated density value and the density reference value 33b to determine the availability of the rock. Specifically, the usability determination unit 45b reads the density reference value 33b from the information storage unit 30b, and compares the density estimated value with the density reference value (S209). When the estimated density value is equal to or higher than the density reference value, the rock R is determined to be usable (S111), and when the estimated density value is smaller than the density reference value, the rock R is determined to be unusable (S113). ). Thereafter, the usability determination unit 45b displays the determination result (whether or not the rock R can be used) on the display 60 of the computer 23 together with the density estimation value, for example.

[Appearance photo acquisition process]
Then, an appearance photograph acquisition process is performed (S121). The details of the appearance photo acquisition process are as described in the first embodiment.

[Current location acquisition process]
Subsequently, a current location acquisition process is performed (S123). The details of the current location acquisition process are as described in the first embodiment.

[Data recording process]
Subsequently, the availability determination unit 45b associates the availability of the rock R, the estimated density value, the current position information obtained from the GPS device 27, and the appearance photograph data of the rock R obtained from the digital camera 25. Is stored in the information storage unit 50 (S225). Thereafter, when the quality evaluation of the rock is continued (Yes in S127), the process returns to S103, and in other cases (No in S127), the process ends.

  According to the quality evaluation method and the quality evaluation apparatus described above, the quality evaluation of the rock R can be performed by a simple operation of hitting the rock R with the hammer 11. Therefore, the effect similar to 1st Embodiment is acquired also by the quality evaluation method of this embodiment.

(Third embodiment)
Next, a third embodiment of the rock quality evaluation method according to the present invention will be described with reference to FIGS. The equipment configuration of the evaluation apparatus of this embodiment is the same as that of the first embodiment (FIG. 1). In the present embodiment, the processing in the computer 23 is different from that in the first embodiment. Accordingly, the information stored in the information storage unit 30c of the computer 23 and the configuration of the calculation unit 40c are different from those in the first embodiment. Is different. In the present embodiment, the same or equivalent components and processes as those in the first or second embodiment are denoted by the same reference numerals in the drawings, and redundant description is omitted.

  As shown in FIG. 10, the information storage unit 30c stores a water absorption rate correlation 31a, a water absorption rate reference value 33a, a density correlation 31b, and a density reference value 33b. And the calculating part 40a is provided with the elastic coefficient calculation part 41, the water absorption rate estimation part 43a, the density estimation part 43b, and the usability determination part 45b.

  Subsequently, the quality evaluation method of the present embodiment performed using the above-described evaluation apparatus will be described with reference to FIG.

[Water absorption rate correlation preparation process]
First, a water absorption rate correlation preparation step is performed (S101). The details of the water absorption rate correlation preparation step are as described in the first embodiment.

[Density correlation preparation process]
Subsequently, a density correlation preparation step is performed (S201). Details of the density correlation preparation step are as described in the second embodiment. In addition, a water absorption rate correlation preparation process, a density correlation preparation process, and an execution order may be reverse.

[Hitball exploration process]
Subsequently, a hit ball exploration process is performed (S103, S105). Details of the hit ball exploration process are as described in the first embodiment.

[Water absorption rate estimation process]
Then, a water absorption rate estimation process is performed (S107). The details of the water absorption rate estimation step are as described in the first embodiment.

[Density estimation process]
Subsequently, a density estimation step is performed (S207). The details of the density estimation step are as described in the second embodiment. The water absorption rate estimation step, the density estimation step, and the execution order may be reversed.

[Usability determination process]
Subsequently, the usability determination unit 45c determines whether or not the rock can be used based on the comparison between the water absorption rate estimated value and the water absorption rate reference value 33a and the density estimated value and the density reference value 33b. Specifically, the usability determination unit 45c reads the water absorption rate reference value 33a from the information storage unit 30c, and compares the water absorption rate estimated value with the water absorption rate reference value. Furthermore, the usability determination unit 45c reads the density reference value 33b from the information storage unit 30c, and compares the estimated density value with the density reference value (S309). Here, when the condition that “the water absorption rate estimated value is equal to or less than the water absorption rate standard value and the density estimated value is equal to or greater than the density standard value” is satisfied, the rock R is determined to be usable (S111). Otherwise, it is determined that the rock R is unusable (S113). Thereafter, the usability determination unit 45c displays the determination result (whether or not the rock R can be used) on the display 60 of the computer 23 together with the estimated water absorption value and the estimated density value, for example.

[Appearance photo acquisition process]
Then, an appearance photograph acquisition process is performed (S121). The details of the appearance photograph acquisition process are as described in the first embodiment, and thus a duplicate description is omitted.

[Current location acquisition process]
Subsequently, a current location acquisition process is performed (S123). Since the details of the current location acquisition process are as described in the first embodiment, a duplicate description is omitted.

[Data recording process]
Subsequently, the availability determination unit 45b determines whether the rock R can be used, the estimated water absorption rate, the estimated density, the current position information obtained from the GPS device 27, and the appearance of the rock R obtained from the digital camera 25. The photograph data is associated and stored in the information storage unit 50 (S325). Thereafter, when the quality evaluation of the rock is continued (Yes in S127), the process returns to S103, and in other cases (No in S127), the process ends.

  According to the quality evaluation method and the quality evaluation apparatus described above, the quality evaluation of the rock R can be performed by a simple operation of hitting the rock R with the hammer 11. Therefore, the same effects as those of the first and second embodiments can be obtained by the quality evaluation method of the present embodiment. Moreover, according to the quality evaluation method and quality evaluation apparatus of the present embodiment, it is possible to determine whether or not the material can be used based on not only the water absorption rate of rock but also the density.

  DESCRIPTION OF SYMBOLS 1 ... Quality evaluation apparatus, 11 ... Hammer, 11a ... Hitting part, 11b ... Accelerometer, 11d ... Hitting surface, 23 ... Computer (arithmetic unit), 30a, 30b, 30c ... Information storage part (Water absorption rate correlation storage means, Density correlation storage means), 31a ... water absorption rate correlation, 31b ... density correlation, 33a ... water absorption rate reference value, 33b ... density reference value, 40a, 40b, 40c ... calculation unit, 41 ... elastic coefficient calculation unit, 43a ... water absorption rate estimation part, 43b ... density estimation part, 45a, 45b, 45c ... usability judgment part, R ... rock.

Claims (9)

A method for evaluating the quality of natural rocks,
The elastic modulus and water absorption rate of the rock material determined based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the water absorption rate of the rock material obtained by the predetermined water absorption rate measurement method. The water absorption rate correlation preparation step for storing the correlation in the calculation device as the water absorption rate correlation,
Hitting a rock with a metal hammer having an acceleration sensor and a spherical hitting surface, and a hitting ball exploration step for causing the arithmetic unit to calculate an elastic coefficient of the rock based on acceleration data obtained by the acceleration sensor;
Water absorption rate estimation step of causing the arithmetic unit to estimate the water absorption rate of the rock based on the elastic coefficient calculated in the hit ball exploration step and the water absorption rate correlation stored in the water absorption rate correlation preparation step When,
Usability to determine whether or not the rock can be used for the application based on a comparison between the estimated water absorption value obtained in the water absorption estimation step and a water absorption reference value set in advance according to the use of the rock. A determination process;
A rock quality evaluation method characterized by comprising: Correlation between the elastic modulus and density of the rock material obtained based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the density of the rock material obtained by the predetermined density measurement method Is stored in a computing device as a density correlation, a density correlation preparation step,
A density estimation step for causing the arithmetic unit to estimate the density of the rock based on the elastic modulus calculated in the hit ball exploration step and the density correlation stored in the density correlation preparation step; Prepared,
In the availability determination step,
Based on the comparison between the density estimation value obtained in the density estimation step and a density reference value preset according to the use of the rock, it is determined whether or not the rock can be used for the use. The rock quality evaluation method according to claim 1. A method for evaluating the quality of natural rocks,
Correlation between the elastic modulus and density of the rock material obtained based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the density of the rock material obtained by the predetermined density measurement method Is stored in a computing device as a density correlation, a density correlation preparation step,
Hitting a rock with a metal hammer having an acceleration sensor and a spherical hitting surface, and a hitting ball exploration step for causing the arithmetic unit to calculate an elastic coefficient of the rock based on acceleration data obtained by the acceleration sensor;
A density estimation step for causing the arithmetic unit to estimate the density of the rock based on the elastic modulus calculated in the hitting ball exploration step and the density correlation stored in the density correlation preparation step;
A use determination step for determining whether or not the rock can be used for the use based on a comparison between the density estimation value obtained in the density estimation step and a density reference value set in advance according to the use of the rock; ,
A rock quality evaluation method characterized by comprising: The predetermined elastic modulus measurement method in the correlation preparation step is:
4. The method according to claim 1, wherein the rock material is hit with the hammer and the arithmetic unit calculates an elastic coefficient of the rock material based on the acceleration data. 5. Rock quality evaluation method. The hammer in the hit ball exploration process is
The rock quality evaluation method according to any one of claims 1 to 4, further comprising a spherical hitting portion including the hitting surface. In the hit ball exploration process,
The rock quality evaluation method according to any one of claims 1 to 5, wherein a particle diameter of the rock is 15 cm or more, and a mass of the hammer is less than 3 kg. A quality evaluation device for natural rocks,
A metal hammer having an acceleration sensor and a spherical striking surface;
An arithmetic unit that processes acceleration data obtained by the acceleration sensor when the rock is hit with the hammer, and
The arithmetic unit is:
The elastic modulus and water absorption rate of the rock material determined based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the water absorption rate of the rock material obtained by the predetermined water absorption rate measurement method. A water absorption rate correlation storage means for storing the correlation of
An elastic coefficient calculating means for calculating an elastic coefficient of the rock based on the acceleration data obtained by the acceleration sensor;
Water absorption rate estimating means for estimating the water absorption rate of the rock based on the elastic coefficient calculated by the elastic coefficient calculating unit and the water absorption rate correlation stored in the water absorption rate correlation storage unit;
Usability to determine whether or not the rock can be used for the application based on a comparison between the estimated water absorption value obtained by the water absorption estimation means and a water absorption standard value set in advance according to the use of the rock A determination means;
A rock quality evaluation apparatus characterized by comprising: The arithmetic unit is:
Correlation between the elastic modulus and density of the rock material obtained based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the density of the rock material obtained by the predetermined density measurement method Density correlation storage means for storing
Density estimating means for estimating the density of the rock based on the elastic coefficient calculated by the elastic coefficient calculating means and the density correlation stored in the density correlation storage means;
Further comprising
The usability determining means includes
Further determining whether or not the rock can be used for the use based on a comparison between a density estimated value obtained by the density estimating means and a density reference value set in advance according to the use of the rock. The quality evaluation apparatus according to claim 7. A quality evaluation device for natural rocks,
A metal hammer having an acceleration sensor and a spherical striking surface;
An arithmetic unit that processes acceleration data obtained by the acceleration sensor when the rock is hit with the hammer, and
The arithmetic unit is:
Correlation between the elastic modulus and density of the rock material obtained based on the elastic modulus of the rock material obtained by the predetermined elastic modulus measurement method and the density of the rock material obtained by the predetermined density measurement method Density correlation storage means for storing
An elastic coefficient calculating means for calculating an elastic coefficient of the rock based on the acceleration data obtained by the acceleration sensor;
Density estimating means for estimating the density of the rock based on the elastic coefficient calculated by the elastic coefficient calculating means and the density correlation stored in the density correlation storage means;
Based on a comparison between the density estimation value obtained by the density estimation unit and a density reference value set in advance according to the use of the rock, a use determination unit for determining whether or not the rock can be used for the use; ,
A rock quality evaluation apparatus characterized by comprising:

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