JP2013053871A - Quality evaluation method and quality evaluation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quality evaluation method and a quality evaluation device, capable of facilitating the quality evaluation of an underwater base rock or rock.SOLUTION: A quality evaluation method for evaluating the quality of an underwater base rock R that comes from nature includes: an acceleration data acquisition process for allowing a hitting surface 11d of a hammer 11 having an acceleration sensor 11b and the spherical hitting surface 11d to collide with the base rock R existing on the sea bottom to acquire acceleration data to be obtained with the acceleration sensor 11b; a deformation characteristic calculation process for allowing a computer 23 to calculate the deformation characteristics of the base rock R by using the elastic contact theory of Hertz on the basis of the acceleration data; and a quality determination process for allowing the computer 23 to determine the quality of the base rock R on the basis of the deformation characteristics acquired in the deformation characteristic calculation process.

Description

  The present invention relates to a quality evaluation method and a quality evaluation apparatus for evaluating the quality of rocks or rocks derived from nature in water.

  Conventionally, natural rocks or rocks have been used for various purposes in construction projects. For example, naturally derived rock mass plays an important role as a foundation support layer that supports the loads of various structures. Although there are several types of foundations, especially for direct foundations or caisson foundations, in order to support the load from the foundations, appropriate rock mass with strength and rigidity suitable for this is required. For this reason, it is necessary to appropriately carry out surveys and tests by the method defined by JIS during construction for the strength and hardness of the rock mass. As such an investigation method and a test method, those described in Non-Patent Document 1 below are known. That is, according to the judgment criteria as described in Non-Patent Document 1, the geological engineer determines whether the rock or rock is based on the visual judgment of the rock or rock, the sound of hitting by the rock hammer, and the surrounding topography and geological composition. Judge the quality.

JP 2004-150946 A

Japan Dam Association, “Construction of Phil Dam”, pp.239, Table 3.5.1

  However, this method requires a skilled geological engineer and may cause individual differences in judgment. Further, for example, in construction work such as a quay in a harbor, there is a case where a rock or rock to be determined is on the seabed. In this case, it is conceivable to transport rocks and the like to the surface of the water for the judgment of the quality, but it is troublesome and lacks quickness. In addition, it is conceivable that a geological engineer dives and makes a visual judgment of rock or rock on the sea floor, but since there are few engineers who have both high skills as divers and high skills as geological engineers, this is also easy It lacks sex.

  In view of such a problem, an object of the present invention is to provide a quality evaluation method and a quality evaluation apparatus capable of easily performing quality evaluation of a rock or rock existing in water.

  The inventors focused on the fact that the quality of rock or rock can be determined based on the deformation coefficient, and Hertz's elastic contact theory can be used to measure the deformation coefficient. That is, according to Hertz's elastic contact theory, a hammer is made to collide with the target rock or rock, and the deformation characteristics of the rock or rock can be known based on the acceleration waveform of the hammer at the time of collision. Then, the present inventors have found that Hertz's elastic contact theory is established even when a rock or rock and a hammer collide in water, and have completed the present invention.

  The quality evaluation method of the present invention is a quality evaluation method for evaluating the quality of rocks or rocks derived from nature in water, and the impact of a hammer having an acceleration sensor and a spherical impact surface on the rocks or rocks existing in water. An acceleration data acquisition step of colliding surfaces and acquiring hammer acceleration data with an acceleration sensor, and a deformation characteristic calculation step of causing a calculation device to calculate the deformation characteristics of a rock or rock using Hertz's elastic contact theory based on the acceleration data; And a quality determination step of determining the quality of the rock mass or rock based on the deformation characteristics obtained in the deformation characteristic calculation step.

  In this quality evaluation method, the deformation characteristics of a rock mass or rock are calculated by calculation using Hertz's elastic contact theory based on acceleration data when a hammer collides with the target rock mass or rock. Then, based on the deformation characteristics, the quality of the rock mass or rock is determined. Therefore, according to this quality evaluation method, in order to collect acceleration data, for example, in the underwater site such as the seabed, a simple operation such as causing a diver to collide with a rock or rock can be performed. In other words, it is not necessary to have a rare engineer who has the skills of both a geological engineer and a diver, and the quality of the rock mass or rock can be easily evaluated in the underwater site.

  Specifically, in the quality assessment process, engineering classification of the rock mass or rock is performed based on a predetermined correspondence table showing the correspondence between the deformation characteristics of the rock mass or rock and the rock mass grade, and the rock mass grade of the rock mass or rock quality is determined. It is good also as obtaining information about. By classifying the target rock mass or rock according to the rock mass grade, it is possible to evaluate whether or not the rock mass or rock can be used as the support layer of the structure foundation.

  Further, in the quality determination step, the water absorption rate of the rock mass or rock may be obtained as quality-related information based on a predetermined water absorption rate correlation that represents the correlation between the deformation characteristics of the rock mass or rock and the water absorption rate. Further, in the quality determination step, the density of the rock mass or rock may be obtained as information on the quality based on a predetermined density correlation representing the correlation between the deformation characteristics of the rock mass or the rock and the density.

  The present inventors have found that the water absorption rate and density of a rock mass or rock have a correlation with the deformation characteristics of the rock mass or rock. Therefore, the water absorption rate and density can be obtained based on the deformation characteristics of the rock mass or rock. By obtaining the water absorption rate and density of the target rock or rock, it can be used as a judgment material for the use of the rock or rock.

  The quality evaluation apparatus of the present invention is a quality evaluation apparatus for evaluating the quality of rocks or rocks derived from nature in water, a hammer having an acceleration sensor and a spherical collision surface, and the collision surface of the hammer exists in water Acceleration data acquisition means to acquire acceleration data obtained by the acceleration sensor when it collides with rock or rock to be deformed, and deformation characteristics calculation to calculate the deformation characteristics of rock or rock using Hertz's elastic contact theory based on the acceleration data And a quality judgment means for judging the quality of the rock mass or the rock based on the deformation characteristics obtained by the deformation characteristic calculation means.

  In this quality evaluation apparatus, the deformation characteristics of a rock or rock are calculated by calculation using Hertz's elastic contact theory based on acceleration data when a hammer collides with a target rock or rock. Then, based on the deformation characteristics, the quality of the rock mass or rock is determined. Therefore, according to this quality evaluation apparatus, for example, in an underwater field such as the seabed, a simple operation such as causing a diver to collide with a rock or rock to collect acceleration data may be performed. In other words, it is not necessary to have a rare engineer who has the skills of both a geological engineer and a diver, and the quality of the rock mass or rock can be easily evaluated in the underwater site.

  The quality evaluation apparatus of the present invention includes at least a hammer, is movable in water, and obtains information related to acceleration data, and predetermined information on the water based on the information obtained by the underwater movement unit. You may provide the water treatment part which processes. According to this configuration, it is possible to separate an underwater moving unit that collects information in the vicinity of an underwater rock or rock in the quality evaluation device and an overwater processing unit that processes the information on water.

  The quality evaluation device of the present invention is obtained by a GPS device that acquires position information of the water treatment unit by GPS, a relative position information acquisition unit that acquires relative position information of the underwater moving unit with respect to the water treatment unit, and a GPS device. The absolute position information acquisition unit for acquiring the absolute position information of the underwater moving unit based on the position information and the relative position information, and when the hammer and the rock or rock collide, An information storage unit that stores the information in association with each other. According to this configuration, the absolute position of the rock or the rock estimated from the absolute position of the underwater moving part can be associated with the quality of the rock or the rock obtained from the information on the acceleration data.

  The hammer hitting portion may be a sphere, and the mass of the hammer may be less than 10 kg. If the mass of the striking part is less than 10 kg, it is easy to carry and handle.

  ADVANTAGE OF THE INVENTION According to this invention, the quality evaluation method and quality evaluation apparatus which can perform the quality evaluation of the bedrock or rock which exists in water easily can be provided.

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 usage pattern of the quality evaluation apparatus of FIG. It is a figure which shows the structure of the computer of the quality evaluation apparatus of FIG. 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 seabed excavation construction using the quality evaluation method of this invention. It is a figure which shows the method of the investigation for re-digging depth determination. It is sectional drawing which shows the front-end | tip part of the striking instrument of FIG. It is a figure which shows the structure of the computer of the quality evaluation apparatus of 2nd Embodiment. (A) is an example of the graph which shows the correlation with the elastic modulus of a rock, and a water absorption rate, (b) is an example of the graph which shows the correlation with the elastic modulus of a rock, and an absolute dry density. It is a flowchart which shows 2nd Embodiment of the quality evaluation method of this invention. It is a figure which shows 3rd Embodiment of the quality evaluation apparatus of this invention.

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

(First embodiment)
In FIG. 1, the quality evaluation apparatus 1 of this embodiment is shown. The quality evaluation apparatus 1 is an apparatus for performing quality evaluation of naturally derived rocks or rocks existing in water. Underwater natural rocks include, for example, seabed rocks, and underwater natural rocks include, for example, rocks (drilling) generated by excavating the seabed rocks.

  In FIG. 2, an example of the usage pattern of the quality evaluation apparatus 1 is shown. As shown in the figure, the quality evaluation apparatus 1 is used for investigating a bedrock R on the seabed for use as a support layer for the caisson foundation C. In the region shown in FIG. 2, the foundation rubble layer 101 is provided on the rock mass R that appears by excavating the seabed, and the caisson foundation C is further placed on the foundation rubble layer 101, and the upper part of the caisson foundation C is the sea level H. Exposed above. The caisson foundation C functions as an upright bank that reflects wave energy. Since the construction method of the caisson foundation C is a well-known method, detailed description is abbreviate | omitted. During excavation work of the rock mass R, the quality assessment of the rock mass R using the quality evaluation apparatus 1 and the quality assessment method of the present embodiment is performed, and whether or not the rock mass R can be used as a support layer for the caisson foundation C. Be investigated. Specifically, as shown in FIG. 2, the diver D has an underwater moving part 1 a that is a part of the quality evaluation device 1 and dives on the seabed, and performs data collection work on the rock mass R. The water treatment unit 1b, which is another part of the quality evaluation apparatus 1, is mounted on the ship B, and the underwater movement unit 1a and the water treatment unit 1b are connected by a cable 12. Although details will be described later, the surface treatment unit 1b performs predetermined information processing based on data collected by the underwater movement unit 1a.

  As shown in FIG. 1, 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, a computer (computing device). ) 23, an acoustic sounding device (relative position information acquisition unit) 25, and a GPS device 27. Among them, the hammer 11 belongs to the underwater moving unit 1a, and the charge amplifier 13, the DC power supply device 15, the terminal panel 19, the AD converter 21, the computer 23, the acoustic sounding device 25, and the GPS device 27 are described above. It belongs to the water treatment section 1b.

  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 striking the rock R which is a quality evaluation target. The diver D 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 striking portion 11a constitutes a spherical striking surface (collision surface) 11d that actually collides with the rock mass R. Since the hammer 11 is used in the sea, for example, it is preferable that the hammer 11 is made of stainless steel to prevent rust.

  The mass of the hammer 11 is preferably less than 10 kg from the viewpoint of facilitating carrying and handling on the seabed. 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 strikes the rock R with the hammer 11, the acceleration sensor 11b detects an impact waveform generated by a collision between the striking surface 11d and the rock as an acceleration waveform (acceleration data). The detected acceleration waveform is transmitted as an acceleration signal to the water treatment unit 1b on the ship B through the cable 12. In the surface treatment unit 1 b, an acceleration signal is input to the charge amplifier 13 and further transmitted to the computer 23 via 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 the evaluation result of the rock R. Since the computer 23 is preferably small and lightweight from the viewpoint of easy carrying and handling, it is preferable to employ a laptop computer.

  A GPS (Global Positioning System) device 27 calculates the current position (absolute position) of the surface processing unit 1 b based on radio waves received from GPS satellites, and transmits the current position information to the computer 23. The acoustic sounding device (relative position information acquisition unit) 25 emits sound waves toward the seabed, analyzes the reflected waves, and measures the position of the diver D on the seabed or the position of the underwater moving unit 1a. The measurement data obtained by the acoustic sounding device 25 indicates the three-dimensional relative position of the underwater moving unit 1a with respect to the surface processing unit 1b, and the relative position information is transmitted to the computer 23. Since the GPS device 27 and the acoustic sounding device 25 having such functions are known, further detailed description is omitted.

〔文献〕菊地宏吉ら、「ダム基礎岩盤の耐荷性に関する地質工学的総合評価」、応用地質、日本応用地質学会、１９８４年、特別号、ｐ．１０３−１１８． As shown in FIG. 3, the computer 23 includes an information storage unit 30, a calculation unit 40, an information storage unit (information storage unit) 50, and a display 60. The information storage unit 30 stores a rock grade table (correspondence table) 31 and a usage standard 33. As illustrated in Table 1 below, the rock grade table 31 is information indicating the correspondence between the rock deformation coefficient (proportional constant between stress and strain) and the rock grade, and is described in, for example, the following documents. A well-known table is employed. Table 1 also shows the correspondence between the static elastic modulus of the rock mass and the rock mass grade. Both the deformation coefficient and the static elastic modulus are evaluation indexes representing the deformation characteristics of the rock mass or rock. However, when the rock mass is deformed by an external force such as loading, there is a difference that the deformation coefficient takes into account the displacement associated with the closing of the crack existing in the rock mass, whereas the static elastic modulus does not consider it. That is, it can be said that the deformation coefficient is an evaluation index that represents the deformation characteristics of the rock that contains the crack, and the static elastic coefficient is an evaluation index that represents the deformation characteristics of the rock and the rock that does not have the crack.

[Literature] Hirokichi Kikuchi et al., "Geotechnological comprehensive evaluation of load resistance of dam foundation rock", Applied Geology, Japan Society of Applied Geology, 1984, Special Issue, p. 103-118.

  The usage standard 33 is information indicating a grade for which the rock mass R can be used as a support layer of the caisson foundation C. For example, information such as “the rock that can be used as the support layer of the caisson foundation C has a rock grade of B grade or CH grade” is stored in the information storage unit 30 as the use standard 33. The usage standard 33 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 30 and the information storage unit 50 are storage areas of a storage device built in the computer 23, for example.

  The calculation unit 40 includes a deformation coefficient calculation unit (acceleration data acquisition unit, deformation characteristic calculation unit) 41, a grade determination unit (quality determination unit) 43, a usability determination unit 45, and an evaluation position calculation unit (absolute position information acquisition). Part) 47. The deformation coefficient calculation unit 41, the grade determination unit 43, the usability determination unit 45, and the evaluation position calculation unit 47 read a predetermined quality evaluation program on hardware such as the CPU and RAM of the computer 23. These are components realized by software by operating a communication module, an input device, an output device, and the like under the control of a CPU, and reading and writing data in a RAM and an auxiliary storage device.

The deformation coefficient calculation unit 41 calculates the deformation coefficient of the rock mass R using Hertz's elastic contact theory based on the acceleration signal obtained from the acceleration sensor 11b. According to Hertz's elastic contact theory, the contact time _Tc between the sphere and the elastic body plane when the sphere collides with the surface of the elastic body 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 deformation coefficient of the rock mass R, Hertz's elastic contact theory is applied. That is, in this embodiment, in the Hertz elastic contact theory, the striking portion 11a of the hammer 11 is applied to the sphere, and the rock mass 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 mass R, a value of about 0.2 may be used as the Poisson's ratio of a general rock. Further, T _c and V ₀ can be calculated from an impact waveform (acceleration data) represented by an 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. Here, since the hit object is the rock mass R, E ₂ indicates a “deformation coefficient” which is a proportional constant between the stress and strain of the rock mass R.

The grade determination unit 43 performs engineering classification of the rock mass R based on the deformation coefficient E ₂ of the rock mass R obtained by the deformation coefficient calculation unit 41. The engineering classification of the rock mass refers to, for example, determining the rock mass grade of the target rock mass according to Table 1 described above. That is, the grade determining unit 43 reads the rock grade table 31 stored in the information storage unit 30, the rock grades corresponding to the value of the deformation coefficient E _2, obtained as grade rock R.

  The evaluation position calculation unit 47 calculates the absolute position (hereinafter referred to as “evaluation position”) of the location of the rock mass R evaluated by hitting. Specifically, the evaluation position calculation unit 47 is based on the absolute position information of the surface treatment unit 1b obtained by the GPS device 27 and the relative position information of the underwater movement unit 1a obtained by the acoustic sounding device 25. The absolute position of the underwater moving unit 1a is calculated. By calculating the absolute position of the underwater moving part 1a at the time of striking the rock R (including immediately before striking or immediately after striking), the absolute position of the location of the rock R evaluated by striking is acquired. Can do.

  The usability determination unit 45 compares the grade of the rock mass R obtained by the grade determination unit 43 with the use standard 33 read from the information storage unit 30. When the grade of the rock mass R satisfies the use standard 33, it is determined that the rock mass R can be used as a support layer for the caisson foundation C. On the other hand, when the grade of the bedrock R does not satisfy the use standard 33, it is determined that the bedrock R cannot be used as the support layer of the caisson foundation C.

  Thereafter, the usability determination unit 45 displays the determination result (whether the rock mass R can be used) on the display 60 of the computer 23 together with the grade of the rock mass R, for example. Further, the usability determination unit 45 associates the availability of the rock mass R, the rock mass grade, and the evaluation position information obtained from the evaluation position calculation unit 47 and accumulates them in the information accumulation unit 50.

  Furthermore, the usability determination unit 45 compares the grade of the rock mass related to the previous evaluation accumulated in the information accumulation unit 50 with the grade of the rock mass R related to the current evaluation, thereby determining whether or not the quality of the rock mass has changed. May be determined.

  Then, the quality evaluation method of the rock mass R performed using the above-mentioned quality evaluation apparatus 1 is demonstrated with reference to FIG.

[Correspondence table preparation process]
A rock grade table 31 indicating the correspondence between the rock deformation coefficient and the rock grade is stored in the information storage unit 30 of the computer 23 (S101). Specifically, for example, the above-described Table 1 is stored in the information storage unit 30 as electronic data.

[Hitball exploration process]
First, the evaluation position of the rock mass R is selected on the seabed (S103). Next, the deformation coefficient of the rock mass R is calculated by the hitting ball exploration method. Specifically, the diver D hits the selected rock mass R with the hitting surface 11 d of the hammer 11. The acceleration generated in the hammer 11 at the time of hitting is detected by the acceleration sensor 11b, and the acceleration signal is input to the computer 23 and input to the deformation coefficient calculation unit 41 of the calculation unit 40 (acceleration data acquisition step). And the deformation coefficient calculation part 41 calculates the deformation coefficient of the rock mass R from the above-mentioned Formula (1) based on an acceleration signal (S105: deformation characteristic calculation process).

[Grading process]
Subsequently, the grade determination unit 43 determines the grade of the rock mass R based on the deformation coefficient calculation value obtained by the hitting ball exploration process and the rock mass grade table 31 (S107). Specifically, the grade determination unit 43 reads the rock mass grade table 31 from the information storage unit 30 and obtains the rock mass grade corresponding to the above-described deformation coefficient calculation value as the grade of the rock mass R (quality determination step).

[Usability determination process]
Subsequently, the usability determining unit 45 compares the obtained grade of the rock mass R with the usage standard 33 to determine the availability of the rock mass R. Specifically, the usability determining unit 45 reads the usage standard 33 from the information storage unit 30 and compares it with the grade of the rock mass R (S109). If the grade of the rock mass R satisfies the usage standard 33, the rock mass R is determined to be usable (S111), and if the grade of the rock mass R does not satisfy the usage standard 33, the rock mass R is determined to be unusable (S113). Thereafter, the usability determination unit 45 displays the determination result (whether the rock mass R can be used) on the display 60 of the computer 23 together with the grade of the rock mass R, for example.

[Evaluation position acquisition process]
Subsequently, the evaluation position calculation unit 47 calculates the current absolute position of the underwater movement unit 1a based on the information obtained from the GPS device 27 and the information obtained from the acoustic sounding device 25 (S123). . Note that the evaluation position acquisition step may be performed before the hit ball exploration step.

[Data recording process]
Subsequently, the availability determination unit 45 associates the availability of the rock mass R, the grade of the rock mass R, and the evaluation position information obtained in the evaluation position acquisition process, and accumulates them in the information accumulation unit 50 (S125). Thereafter, when the quality evaluation of the rock mass R is continued (Yes in S127), the process returns to S103, and in other cases (No in S127), the process is terminated. If the diver D moves the seabed and changes the evaluation position of the rock mass R, the above processing is repeated, and the deformation coefficients at the multiple locations of the rock mass R that are naturally derived and have variations can be investigated. Survey accuracy can be improved and mapping can be performed.

  In the quality evaluation device 1 and the quality evaluation method, the deformation coefficient of the rock mass R is calculated by calculation using Hertz's elastic contact theory based on the acceleration data when the hammer collides with the rock mass R. Based on the deformation coefficient, the rock mass grade of the rock mass R is determined. Therefore, at the seafloor site, the diver D may perform a simple operation such as hitting the rock R with the hammer 11 in order to collect acceleration data. That is, it is possible to easily evaluate the quality of the rock mass R in the underwater site without requiring a rare engineer who has both the skills of a geological engineer and a diver.

  In addition, according to the quality evaluation apparatus 1 and the quality evaluation method, the work performed by the diver D is mainly only the striking of the rock mass R by the hammer 11, so that one quality evaluation can be performed in a short time, for example, about 30 seconds. This makes it possible to quickly determine whether or not the bedrock R can be used. Therefore, the operation of frequently checking the quality of the rock mass R during the seabed excavation work is also possible. In addition, it is possible to collect a lot of data and perform statistical processing, thereby improving the accuracy of evaluation. In addition, the degree of skill of the diver D has little influence on the accuracy of evaluation. Further, since the mass of the hammer 11 is less than 10 kg, the hammer 11 can be easily carried and handled, and measurement can be easily performed on the seabed. As a result, the bedrock R can be evaluated quickly, and the caisson foundation C can be constructed efficiently.

  Here, the point that Hertz's elastic contact theory is applicable to the collision between the hammer 11 and the rock mass R in water will be examined.

  The present inventors performed deformation coefficient measurement using the quality evaluation apparatus 1 for three types of rock samples, granite, andesite, and quartz andesite. In the measurement, each rock sample was struck with a hammer 11 in a state placed in the air and in a state placed in water, and a deformation coefficient was obtained. The hitting part 11a of the hammer 11 is a sphere having a radius of 2.5 cm and a mass of 600 g made of steel, and a rock block having a diameter of about 30 cm was selected as each rock sample. As shown in FIG. 5, the measurement results showed almost the same measured values of deformation coefficient in the air and in the water regardless of the type of rock. As a result, Hertz's elastic contact theory is valid for underwater collisions as well as in the air, and according to the quality evaluation apparatus 1, it is confirmed that the deformation coefficient of the rock mass R can be obtained in the water as in the air. It was done.

The conclusion that Hertz's elastic contact theory holds even in underwater collisions is estimated as follows. The contact time T _{c in the} above formula (1) depends only on the specific physical characteristics (particularly, the deformation coefficient or the elastic coefficient) of the two objects that are instantaneously touched by the collision, and the collision occurs in the air or underwater. It is considered that it is not affected by the conditions such as Moreover, since water is considered to be an inviscid fluid from an engineering viewpoint, it is considered that the water does not intervene between the contact surfaces at the moment of collision of the two objects. In addition, since water does not intervene between the contact surfaces of the two objects, the influence of the presence of water on the acceleration at the collision of the two objects is small, and as a result, V ₀ (collision speed) obtained from the acceleration waveform. However, it is considered that there is no significant difference in engineering between air and water.

Also, E ₁ (elastic coefficient of the striking portion 11a of the hammer 11), μ ₁ (Poisson's ratio of the striking portion 11a), R (radius of the striking portion 11a), M (mass of the striking portion 11a) in the formula (1) Is a characteristic of an object and does not change between the air and water. Regarding the rock mass R, it is considered that the rock mass that is the target in the civil engineering field is also saturated in the air due to the influence of rainfall and groundwater, just as the void of the rock mass R is saturated in the water. . In other words, under normal natural conditions, it is almost impossible for the air gaps in the rocks to reach a dry state. In other words, μ ₂ (Poisson's ratio of the rock mass R) is also considered to be almost the same for the underwater rock mass and the atmospheric rock mass. As described above, parameters that are significantly affected by water are not included in Equation (1), and Hertz's elastic contact theory expressed by Equation (1) is considered to hold in the air and in water as well. .

  Next, an example of excavation work for the seabed rock R using the above-described quality evaluation method will be described with reference to FIG. The rock R in this example is a support layer for the caisson foundation C described above.

  First, the position of the caisson foundation C is determined (S201), and the seabed at that position is excavated to the planned depth (S203). Quality evaluation using the above-described quality evaluation method and quality evaluation apparatus 1 is executed for the rock mass R that appears in the excavation (S205). Here, for example, the evaluation positions are set in a lattice pattern on the rock mass R, and quality evaluation is performed on a plurality of locations on the rock mass R. If the result of the quality evaluation indicates that “can be used as a support layer for the caisson foundation C” is obtained (Yes in S207), the excavation work is terminated (S209). On the other hand, when the result of the quality evaluation indicates that “cannot be used as a support layer for the caisson foundation C” is obtained (No in S207), an investigation for determining the depth of re-excavation is performed (S211). After the re-excavation depth is determined, the process returns to S203 and the above-described processing is repeated.

  Next, an example in which the quality evaluation apparatus 1 is used in the investigation process for determining the re-digging depth in S211 will be described. First, the diver D having the underwater moving part 1a of the quality evaluation apparatus 1 and a core drill (not shown) descends on the bedrock R on the seabed. Next, as shown in FIG. 7, the diver D drills a vertical survey hole 103 having a predetermined depth in the rock mass R using a core drill. The hole diameter of the research hole 103 is about 100 mm or less, for example, and the depth of the research hole 103 is about 1 m, for example. The Thereafter, the diver D obtains acceleration data by hitting the bottom surface 103a of the investigation hole 103 with the hammer 11. The acceleration data is transmitted to the computer 23, and the evaluation result “available” or “unusable” is derived by the above-described calculation.

  Here, when an evaluation result of “available” is obtained, it is found that a high-quality rock is present at a deeper position from the current rock R surface. That is, it is possible to determine that there is a high possibility that a bedrock that can be used as a support layer of the caisson foundation C appears by re-digging the depth of the survey hole 103. Then, the depth corresponding to the depth of the bottom surface 103a of the survey hole 103 is adopted as the planned depth for re-digging.

  In addition, it is difficult to employ | adopt a large diameter core drill from a viewpoint of the ease of handling in the seabed, As a result, the hole diameter of the investigation hole 103 may be small. In this case, it is difficult for the hand of the diver D to enter the investigation hole 103, and the bottom surface 103a may not be hit appropriately. Therefore, when hitting the bottom surface 103a, a hitting instrument 51 as shown in FIGS. 7 and 8 is used.

  As shown in FIG. 8, the striking instrument 51 is configured such that the hammer 11 with the handle portion 11 c removed is attached to the tip of the rod body 53. The hitting instrument 51 includes a slide mechanism 61 and an urging portion 67 as a connecting portion that connects the rod body 53 and the hitting portion 11a. Hereinafter, the extending direction of the rod 53 is the front-rear direction, the end on the side where the hitting portion 11a is provided is the “front end”, and the words including the concepts “front” and “rear” are used to describe the positional relationship. Shall be used. The front surface of the striking portion 11a is a striking surface 11d, and the acceleration sensor 11b is attached to the rear surface of the striking portion 11a.

  The slide mechanism 61 is provided in a hollow portion at the front end of the rod 53, and includes a fixed rail 61b and a movable rail 61a engaged with the fixed rail 61b so as to move back and forth. The fixed side rail 61 b is fixed to the inner wall surface of the hollow portion of the bar 53, and the front end of the moving side rail 61 a protrudes forward from the front end opening of the bar 53. The striking portion 11a is attached to the front end of the moving rail 61a. With such a structure, the striking portion 11a can be translated in the front-rear direction (the extending direction of the rod 3) with respect to the rod 53. Further, in the slide mechanism 61, the forward / backward movement range of the moving rail 61a is limited by a predetermined stopper mechanism (not shown), and therefore there is a front end limit and a rear end limit in the movement range of the striking portion 11a. .

  As the slide mechanism 61, for example, a known slide rail part having a structure in which a ball is sandwiched between the fixed side rail 61b and the moving side rail 61a may be used. The slide mechanism 61 may have another structure as long as it supports the striking portion 11a so as to be movable back and forth.

  Furthermore, the striking instrument 51 includes a biasing portion 67 that biases the striking portion 11a forward. The urging portion 67 includes two arms 69 that can be opened and closed by hinge coupling, and a torsion spring 71 that urges the arms 69 in the opening direction. Since the distal ends of the two arms 69 are hinged to the moving rail 61a and the outer wall surface of the rod 53, the urging force of the torsion spring 71 acts as a force that urges the striking portion 11a forward. To do. The force generated by the torsion spring 71 is adjusted to be zero when the hitting portion 11a is at the front end limit position, and when the hitting portion 11a is retracted from the front end limit position, the torsion spring 71 is adjusted. Exerts a force to push the striking portion 11a forward.

  Based on the above configuration, as shown in FIG. 7, the diver D inserts the tip of the striking instrument 51 into the investigation hole 103, grips the rod body 53, and thrusts downward, thereby causing the bottom surface to hit the bottom portion 11 a. 103a can be hit. As described above, by using the striking instrument 51, the bottom surface 103a can be hit with the hitting portion 11a even when the hand of the diver D is difficult to enter the investigation hole 103.

  In order to obtain appropriate acceleration data applicable to Hertz's elastic contact theory, it is necessary to hit the bottom surface 103a in a state where the movement of the hitting portion 11a due to repulsion at the moment of hitting is allowed. That is, at the moment of hitting, the movement of the hitting part 11a elastically rebounding from the bottom surface 103a must not be hindered. Here, a structure in which the striking portion 11 a is simply fixed to the front end portion of the rod body 53 will be considered. According to the apparatus of this structure, when the diver D performs an operation of piercing the bottom surface 103a, it is easy to perform an operation of pushing forward further for a certain time immediately after the collision between the striking portion 11a and the bottom surface 103a, that is, the striking portion 11a. It tends to be in a state where the movement of bouncing back is hindered. Further, since the hitting portion 11a is in the investigation hole 103 and is difficult to see, it is difficult for the diver D to finely adjust the hitting state of the hitting portion 11a. Therefore, with the structure in which the striking portion 11a is simply fixed to the front end portion of the rod body 53, it is difficult to obtain appropriate acceleration data applicable to Hertz's elastic contact theory.

  On the other hand, according to the striking instrument 51, the striking portion 11 a employs a configuration that is supported so as to be movable in the collision direction (front-rear direction) with respect to the rod body 53. Therefore, at the moment of hitting, the rearward movement of the hitting portion 11a due to repulsion from the bottom surface 103a is allowed. Accordingly, appropriate acceleration data applicable to Hertz's elastic contact theory can be obtained.

  Further, during the above-described piercing operation, the rod body 53 is quickly accelerated forward, so that the striking portion 11a tends to move backward with respect to the rod body 53 due to inertia. At this time, if the hitting portion 11a reaches the rear end limit, the backward movement of the hitting portion 11a at the moment of hitting is limited, and appropriate acceleration data applicable to Hertz's elastic contact theory is obtained. I can't.

  On the other hand, in the striking instrument 51, by providing the biasing portion 67, the striking portion 11a is biased forward by the biasing portion 67 when the rod 53 is accelerated. You can avoid reaching the limit. Therefore, even when the rod 3 is accelerated quickly, it is possible to ensure the backward movement of the hammer due to repulsion and obtain appropriate acceleration data applicable to Hertz's elastic contact theory. It should be noted that, at the moment of hitting, the forward biasing force by the biasing portion 67 is acting, and the rearward movement of the hitting portion 11a is slightly hindered, but the biasing force is the impact force of the hitting The effect of the urging force can be ignored.

(Second Embodiment)
Then, 2nd Embodiment of the quality evaluation apparatus and quality evaluation method of this invention is described. In the present embodiment, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  In the excavation work for the seabed rock as described above, rocks are generated as excavation gaps. Such rocks are lifted on the water by construction machines and used as embankment materials for roads, etc., and therefore, whether or not they satisfy a predetermined quality is evaluated and determined whether or not they can be used as materials. There is a need to. If this determination can be made at a stage where the excavation gap is on the seabed, it is possible to select an appropriate construction machine, to appropriately transport the excavation gap on land, and to efficiently use or discard the excavation gap. . Therefore, in the present embodiment, the diver D descends to the seabed site where the excavation occurs, and the diver D hits the rock on the seabed with the hammer 11.

  In general, it is often determined whether or not the excavated rock can be used for a desired purpose based on the water absorption rate or density of the rock. Therefore, in this embodiment, whether or not the rock can be used is determined based on the water absorption rate or density of the rock. For example, since there is a predetermined correlation between the water absorption rate of the rock and the elastic coefficient, the elastic coefficient of the rock is calculated by hitting the rock with the hammer 11, and the water absorption rate of the rock is calculated based on the calculated elastic coefficient. Is estimated.

  The quality evaluation apparatus according to the present embodiment is different from the quality evaluation apparatus 1 described above in that a computer 223 shown in FIG. The information storage unit 30 of the computer 223 stores a quality correlation (water absorption rate correlation) 231 and a quality reference value 233. According to the experiments by the present inventors, it has been found that there is a correlation represented by a curve as shown in FIG. 10A between the elastic modulus of the rock and the water absorption rate. The quality correlation 231 is information indicating a correlation between the elastic coefficient and the water absorption rate of the rock as described above. A quality correlation 231 is acquired by a water absorption rate correlation preparation step described later, and is stored in the information storage unit 30 in advance.

  The quality standard value 233 is information indicating the upper limit value of the water absorption rate for allowing the rock to be used for a desired application. For example, when rock is used as a rock material for a rockfill dam, the water absorption rate of the rock is required to be 3.0% or less, so the information that “water absorption reference value = 3.0%” is provided. It is stored in the information storage unit 30. The quality reference value 233 is set based on, for example, a special specification or construction plan, and is input in advance by a key operation of the computer 223 by the user. The information storage unit 30 and the information storage unit 50 are storage areas of a storage device built in the computer 223, for example.

  The calculation unit 40 includes an elastic coefficient calculation unit 241, a quality estimation unit 243, a usability determination unit 245, and an evaluation position calculation unit 47. The elastic coefficient calculation unit 241, the quality estimation unit 243, the usability determination unit 245, and the evaluation position calculation unit 47 read a predetermined quality evaluation program on hardware such as the CPU and RAM of the computer 223, thereby It is a component realized by software by operating a communication module, an input device, an output device, and the like under control, and reading and writing data in a RAM and an auxiliary storage device.

  The elastic coefficient calculation unit 241 calculates the elastic coefficient of the rock using Hertz's elastic contact theory based on the acceleration signal obtained from the acceleration sensor 11b. The quality estimation unit 243 estimates the water absorption rate of the rock based on the rock elastic coefficient obtained by the elastic coefficient calculation unit 241. That is, the quality estimation unit 243 reads the quality correlation 231 stored in the information storage unit 30 and obtains the water absorption value corresponding to the elastic coefficient value as the rock water absorption estimation value.

  The usability determination unit 245 compares the water absorption rate estimated value obtained by the quality estimation unit 243 with the quality reference value 233 read from the information storage unit 30. When the water absorption estimated value is equal to or less than the quality reference value 233, it is determined that the rock can be used for a predetermined application (for example, an application as a rock material for a rock fill dam). On the other hand, when the estimated water absorption rate is larger than the quality reference value 233, it is determined that the rock cannot be used for a predetermined application. Thereafter, the usability determination unit 245 displays the determination result (whether or not the rock can be used) on the display 60 of the computer 223 together with the estimated water absorption rate, for example. Furthermore, the usability determination unit 245 associates the availability of rock, the estimated water absorption value, and the evaluation position information obtained from the evaluation position calculation unit 47 and accumulates them in the information storage unit 50.

  Furthermore, the usability determination unit 245 compares the estimated water absorption rate of the rock according to the previous evaluation accumulated in the information storage unit 50 with the estimated value of the water absorption rate of the rock according to the current evaluation. The presence or absence of quality fluctuations may be determined.

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

[Water absorption rate correlation preparation process]
The water absorption correlation indicating the correlation between the elastic coefficient of the rock and the water absorption is stored in the information storage unit 30 of the computer 223 (S301). The water absorption correlation is based on the measurement of the elastic modulus and the 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 having a rock diameter of 15 cm or more is collected as a stone sample. “The medium diameter 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 “medium 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. In addition, the present inventors have obtained the knowledge that the correlation between the elastic coefficient of rock and the water absorption has almost the same relationship regardless of the rock type. In addition, the correlation between the elastic coefficient of the rock and the water absorption rate is confirmed as appropriate, and the correlation between the rock elastic coefficient and the water absorption rate becomes more accurate by plotting this relationship.

  In addition, a rock sample may be collected at the seafloor site where the excavation gap actually occurs, and a water absorption correlation may be obtained based on the rock sample and stored in the information storage unit 30 of the computer 223. In this case, it is possible to acquire a water absorption rate correlation peculiar to the seabed site where excavation slip occurs. 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 diver D selects and collects a rock for quality evaluation on the seabed (S303). In this case, a rock having a particle size of 15 cm or more is selected as the target rock. Next, the elastic modulus of the rock is calculated by the ball hitting method. Specifically, the diver D hits the selected rock with the hitting surface 11 d of the hammer 11. The acceleration generated in the hammer 11 at the time of hitting is detected by the acceleration sensor 11b, and the acceleration signal is input to the computer 223 and input to the elastic coefficient calculation unit 241 of the calculation unit 40. Then, the elastic coefficient calculation unit 241 calculates the elastic coefficient of the rock from the above equation (1) based on the acceleration signal (S305).

[Water absorption rate estimation process]
Subsequently, the quality estimation unit 243 estimates the water absorption rate of the rock based on the elastic coefficient calculation value obtained by the hit ball exploration process and the quality correlation 231. Specifically, the quality estimation part 243 reads the quality correlation 231 from the information storage part 30, and calculates | requires the value of the water absorption rate corresponding to the said elastic coefficient calculation value as a water absorption rate estimated value of a rock (S307).

[Usability determination process]
Subsequently, the usability determining unit 245 compares the estimated water absorption value with the quality reference value 233 to determine whether or not the rock is usable. Specifically, the usability determination unit 245 reads the quality reference value 233 from the information storage unit 30, and compares the water absorption rate estimated value with the quality reference value 233 (S309). When the water absorption rate estimated value is less than or equal to the quality standard value 233, it is determined that the rock is usable (S311), and when the water absorption rate estimated value is greater than the quality standard value 233, it is determined that the rock is unusable. (S313). Thereafter, the usability determination unit 245 displays the determination result (whether or not the rock can be used) on the display 60 of the computer 223 together with the estimated water absorption rate, for example.

[Evaluation position acquisition process]
Subsequently, the evaluation position calculation unit 47 calculates the current absolute position of the underwater movement unit 1a based on the information obtained from the GPS device 27 and the information obtained from the acoustic sounding device 25 (S223). . Note that the evaluation position acquisition step may be performed before the hit ball exploration step.

[Data recording process]
Subsequently, the usability determination unit 245 associates the availability of the rock, the estimated water absorption rate, and the evaluation position information obtained in the evaluation position acquisition process, and accumulates them in the information accumulation unit 50 (S325). Thereafter, when the quality evaluation of the rock is continued (Yes in S327), the process returns to S303, and in other cases (No in S327), the process ends.

  According to the quality evaluation method and the quality evaluation apparatus of the present embodiment, it is possible to perform the quality evaluation of the rock without moving the excavation gap generated on the seabed site from the site. If this evaluation can be performed at the stage where the excavation sludge is at the bottom of the sea, it will be possible to select an appropriate construction machine and appropriately transport the excavation sludge on land, so that the excavation sludge can be used or disposed of efficiently. .

  As described above, whether or not the rock can be used may be determined based on the density of the rock instead of the water absorption rate of the rock. According to the experiments by the present inventors, there is also a predetermined correlation as exemplified in FIG. 10B between the density of the rock and the elastic modulus, and therefore the elasticity of the rock by the hammer 11 hitting the rock. The coefficient is calculated, and the density of the rock is estimated based on the calculated value of the elastic modulus. Then, when the estimated density value of the rock is larger than the density reference value prepared in advance, it is determined that the rock can be used. Such availability determination can be performed following the availability determination based on the water absorption rate of the rock as described above. In this case, the quality correlation (density correlation) 231 stores information indicating the correlation between the elastic modulus and density of the rock as shown in FIG. The quality reference value 233 stores information indicating a lower limit value (density reference value) of the density for allowing the rock to be used for a desired application.

(Third embodiment)
Next, a third embodiment of the quality evaluation apparatus and the quality evaluation method of the present invention will be described with reference to FIG. In the present embodiment, the same or equivalent components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 12, the quality evaluation apparatus 301 of the present embodiment is different from the quality evaluation apparatus 1 described above in that an underwater movement unit 301a is provided instead of the underwater movement unit 1a. The underwater moving unit 301 a includes a cylindrical sheath tube 303 and is configured such that the hammer 11 with the handle portion 11 c removed is housed in the hollow portion of the sheath tube 303. The underwater moving part 301a is suspended from the ship B into the sea by the wire 305 and lowered onto the bedrock R on the seabed. And as shown in FIG. 12, the underwater moving part 301a is used in the state which landed on the rock mass R with the cylinder axis | shaft of the sheath pipe | tube 303 turned vertically. Hereinafter, when words including the concepts of “upper” and “lower” are used in the description, they are based on the attitude of the underwater moving unit 301a in the above-described use state.

  In the underwater moving part 301 a, the striking part 11 a is accommodated in the hollow part of the sheath tube 303. The inner diameter of the sheath 303 is slightly larger than the diameter of the striking portion 11a, and the striking portion 11a can move up and down within the hollow portion. The lower surface of the hitting portion 11a is the hitting surface 11d, and the acceleration sensor 11b is attached to the upper surface of the hitting portion 11a. An electromagnet 307 is provided on the outer upper portion of the sheath 303. The electromagnet 307 can be operated from the water treatment unit 1 b side, and the striking portion 11 a moves upward in the sheath tube 303 by the electromagnet 307 attracting the striking portion 11 a. The electromagnet 307 releases the striking portion 11a that has moved upward, so that the striking portion 11a falls within the sheath tube 303, and the striking surface 11d collides with the rock mass R. At this time, the striking portion 11a may be accelerated and collided with the rock mass R using a spring or the like. Further, it is more preferable that the striking portion 11a is moved to the upper portion in the sheath tube 303 with a wire that can be wound with an electromagnet attached to the tip, and the striking portion 11a is dropped by cutting off the current.

A drainage port 303a that communicates the inside and outside of the tube is provided at the lower part of the sheath tube 303, and when the striking part 11a is dropped, the water in the hollow part is pushed out through the drainage port 303a. Thereby, the resistance of the water which acts on the striking part 11a is reduced, and the striking part 11a falls smoothly in the sheath pipe 303.

  As described above, in the quality evaluation apparatus 301, the underwater moving part 301a can be lowered to the seabed with the wire 305, and the striking part 11a can collide with the bedrock R by the operation from the surface treatment part 1b. Operation without dispatch is also possible.

  The underwater moving unit 301a includes an underwater camera 309 that is attached to the outside of the sheath tube 303 and images the lower side, and a water ejection device 311 that is attached to the outside of the sheath tube 303 and ejects water downward. . Data captured by the underwater camera 309 is transmitted to the surface processing unit 1b, and an operator on the ship B can visually recognize the state of the bedrock R at the landing point through the monitor screen. Further, by the operation of the operator on the ship B, for example, before the sheath pipe 303 is landed, water can be ejected from the water ejection device 311 toward the rock mass R, and rocks and the like at the landing point can be removed. A cable (not shown) for transmitting / receiving the drive signal of the electromagnet 307, the imaging data of the underwater camera 309, the drive signal of the water ejection device 311, and the like is separately provided between the surface treatment unit 1b and the underwater moving unit 301a. Provided.

  As mentioned above, although each embodiment of this invention was described, this invention is not restricted to the said embodiment, You may change in the range which does not change the summary described in each claim.

  For example, in the embodiment, the acceleration data obtained by the underwater moving units 1a and 301a is transmitted to the surface processing unit 1b through the cable 12. However, the data storage for storing and accumulating acceleration data in the underwater moving units 1a and 301a. A part may be provided. For example, an electronic storage medium may be adopted as the data storage unit, and acceleration data obtained by hitting the rock mass R may be stored and accumulated as electronic data in the electronic storage medium. In this case, when the acceleration data accumulated in the electronic storage medium is collected on the ship B, an operation of performing batch processing by the surface processing unit 1b can be considered. As the electronic storage medium, a semiconductor memory, a hard disk device, or the like can be used.

  Moreover, it is good also as a system which the diver D brings into the seabed all the one sets (the underwater moving part 1a and the surface treatment part 1b) of the quality evaluation apparatus 1 shown in FIG. 1 as an underwater moving part. In this case, the diver D can confirm whether the bedrock R can be used on the seabed. In this case, the GPS device 27 and the acoustic sounding device 25 may be installed on the ship B as the water processing unit, and the absolute position of the diver D may be acquired on the ship B. Further, the determination result (usable or unusable) of whether or not the rock mass R can be used may be transmitted from the computer 23 on the diver D side to the computer on the ship B side in real time. Thereby, even on the ship B, the determination result can be known in real time. Note that an electronic device or the like that requires waterproofing / waterproof pressure in the underwater moving unit may be appropriately stored in a housing or the like.

DESCRIPTION OF SYMBOLS 1 ... Quality evaluation apparatus, 1a, 301a ... Underwater moving part, 1b ... Water treatment part, 11 ... Hammer, 11a ... Impacting part, 11b ... Acceleration sensor, 11d ... Impacting surface (collision surface), 23 ... Computer (arithmetic unit, (Acceleration data acquisition means), 25 ... (relative position information acquisition unit), 27 ... GPS device, 31 ... rock grade table (corresponding table), 41 ... deformation coefficient calculation unit (acceleration data acquisition means, deformation characteristic calculation means), 43 ... grade determination section (quality determination means), 231 ... quality correlation (water absorption rate correlation, density correlation), 241 ... elastic coefficient calculation section (deformation characteristic calculation means), 243 ... quality estimation section (quality determination means), 47: Evaluation position calculation unit (absolute position information acquisition unit), 50: Information storage unit (information storage unit), 231: Correlation (water absorption rate correlation, density correlation), R: Rock.

Claims (8)

A quality evaluation method for evaluating the quality of rocks or rocks derived from nature in water,
Acceleration data acquisition step of causing the collision surface of a hammer having an acceleration sensor and a spherical collision surface to collide with the rock or the rock existing in water, and acquiring acceleration data of the hammer with the acceleration sensor;
Based on the acceleration data, using a Hertz elastic contact theory, a deformation characteristic calculation step that causes the calculation device to calculate the deformation characteristics of the rock or rock,
Based on the deformation characteristics obtained in the deformation characteristics calculation process, a quality determination process for determining the quality of the rock mass or the rock,
A quality evaluation method characterized by comprising: In the quality judgment step,
Based on a predetermined correspondence table representing the correspondence between the deformation characteristics of the rock or the rock and the rock grade, the rock or the rock is subjected to engineering classification, and the rock mass or the rock grade of the rock is used as information on the quality. The quality evaluation method according to claim 1, wherein the quality evaluation method is obtained. In the quality judgment step,
The water absorption rate of the rock mass or the rock is obtained as information on the quality based on a predetermined water absorption rate correlation indicating a correlation between the deformation characteristics of the rock mass or the rock and the water absorption rate. The quality evaluation method according to 1. In the quality judgment step,
The density of the rock mass or the rock is obtained as information on the quality based on a predetermined density correlation that represents a correlation between the deformation characteristics and the density of the rock mass or the rock. Quality evaluation method. A quality evaluation device for evaluating the quality of rocks or rocks derived from nature in water,
A hammer having an acceleration sensor and a spherical impact surface;
Acceleration data acquisition means for acquiring acceleration data obtained by the acceleration sensor when the collision surface of the hammer collides with the rock or the rock existing in water;
Based on the acceleration data, a deformation characteristic calculation means for calculating the deformation characteristics of the rock or the rock using Hertz's elastic contact theory,
A quality evaluation apparatus comprising: quality judgment means for judging the quality of the rock mass or the rock based on the deformation characteristics obtained by the deformation characteristic calculation means. An underwater moving unit that includes at least the hammer, is movable in water, and acquires information on the acceleration data;
The quality evaluation apparatus according to claim 5, further comprising: a water processing unit that performs predetermined information processing on the water based on information acquired by the underwater moving unit. A GPS device for acquiring position information of the water treatment unit by GPS;
A relative position information acquisition unit that acquires relative position information of the underwater moving unit with respect to the surface treatment unit;
An absolute position information acquisition unit that acquires absolute position information of the underwater moving unit based on the position information and the relative position information obtained by the GPS device;
The quality according to claim 6, further comprising: an information storage unit that stores the absolute position information and the information related to the acceleration data in association with each other when the hammer and the rock or the rock collide with each other. Evaluation device.   The quality evaluation apparatus according to any one of claims 5 to 7, wherein the hitting portion of the hammer forms a sphere, and the mass of the hammer is less than 10 kg.

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