Method for estimating the strength ratio of rocks, deformation analysis device for ground, deformation analysis method and program for ground.

Abstract

To provide a method for estimating a strength ratio of rocks, capable of accurately estimating the decrease in strength of rocks.SOLUTION: In a first test step, the strength of a first specimen, which is a rock specimen, is determined. In a second test step, the specimen is dried to prepare a second specimen, and a saturation degree of the second specimen is determined. In a third test step, the specimen is dried in the same way as the second specimen, and then is submerged in water to prepare a third specimen, and a strength ratio of the third specimen is determined. In a strength degradation model creation step, a strength ratio of the second specimen is assumed to be 1, and a saturation degree of the third specimen is assumed to be 1. Then, a strength degradation model showing a relation of a change in a saturation degree due to drying and submersion of rocks with a strength ratio of the rocks is created based on the saturation degrees and the strength ratios of the second specimen and the third specimen. In a strength ratio estimation step, the change in the saturation degree due to drying and submersion of the rocks is input into the strength degradation model to estimate the strength ratio of the rocks.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to a method for estimating the strength ratio of rock, a deformation analysis device for ground, a deformation analysis method for ground, and a program. [Background technology]

[0002] When conducting numerical analysis model studies on countermeasures against deformation in mountain tunnels, it is necessary to represent the deformation of the surrounding ground. Regarding ground deformation, analysis methods have been proposed in Non-Patent Literature 1 and Non-Patent Literature 2, which represent the deformation by reducing the strength of the ground. Non-Patent Literature 3 proposes a method in which the strength of the ground material is set according to the degree of saturation obtained by seepage flow analysis, and deformation analysis is performed. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Tsuyoshi Matsunaga, Hiroo Kumasaka, Yoshiyuki Kojima, and Toshihiro Asakura: A Study on Prediction and Countermeasures for Tunnel Deformation Considering the Time-Deterioration of Ground Strength, Transactions of the Japan Society of Civil Engineers, No. 799, III-72, pp. 75-88, 2005. [Non-Patent Document 2] Shimamoto, K., Noshiro, K., Kojima, Y., Tsukada, K., Asakura, T.: A Study on Subgrade Uplift Phenomena in Mountain Tunnels Considering the Effects of Construction and Countermeasures, Journal of Japan Society of Civil Engineers, Series F1, Vol. 69, No. 2, pp. 105-120, 2013. [Non-Patent Document 3] Yoshiya Hata, Koji Ichii: Dynamic analysis of embankment slopes that can consider the effects of rainfall, Journal of the Japan Landslide Society, Vol. 48, No. 4, pp. 187–197, 2011. [Non-Patent Document 4] Shimamoto, K., Kawagoe, K., Noshiro, K., Kobayashi, H., Isoya, A.: Inference of the tunnel ground swelling mechanism focusing on changes in water content, Journal of Japan Society of Civil Engineers, Series F1, Vol. 76, No. 1, pp. 34-48, 2020. [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, the models for ground strength reduction described in Non-Patent Documents 1 and 2 have not been sufficiently validated through rock tests and other methods. The method described in Non-Patent Document 3 only considers the strength reduction associated with increasing saturation. Therefore, there were issues regarding the validity of these models.

[0005] The problem that this invention aims to solve is to provide a method for estimating the strength ratio of rocks, a deformation analysis device for ground, a deformation analysis method for ground, and a program that can accurately estimate the decrease in rock strength and the deformation of the ground. [Means for solving the problem]

[0006] The present invention provides a method for estimating the strength ratio of rock, comprising a first test step, a second test step, a third test step, a strength reduction model creation step, and a strength ratio estimation step. In the first test step, the strength of a first specimen, which is a rock specimen, is determined. In the second test step, the first specimen is dried to create a second specimen, and the saturation of the second specimen is determined assuming that the saturation of the first specimen is 1. In the third test step, the first specimen is dried in the same manner as the second specimen, and then immersed in water to create a third specimen, and the strength of the third specimen is determined, as well as the strength ratio of the third specimen to the strength of the first specimen. In the strength reduction model creation step, the strength ratio of the second specimen to the strength of the first specimen is assumed to be 1, and the saturation of the third specimen is assumed to be 1. Then, using the saturation and strength ratio of the second and third specimens, a strength reduction model is created that shows the relationship between the change in saturation due to drying and immersion of the rock and the strength ratio of the rock to the strength of the first specimen. In the strength ratio estimation process, the change in saturation due to rock drying and water infiltration is input into a strength reduction model to estimate the strength ratio of the rock.

[0007] By creating a strength reduction model based on rock testing, the strength reduction of rocks can be estimated with high accuracy. Furthermore, a strength reduction model is created that shows the relationship between changes in saturation due to rock drying and immersion and the rock's strength ratio. This allows for accurate estimation of the strength reduction of rocks exhibiting slaking properties.

[0008] In the second testing step, the specimens are dried to multiple degrees of dryness to create multiple types of second specimens, and the degree of saturation of these multiple types of second specimens is determined. In the third testing step, the specimens are dried in the same manner as the multiple types of second specimens, and then immersed in water to create multiple types of third specimens, and the strength ratio of these multiple types of third specimens is determined. In the strength reduction model creation step, the strength ratios of the first specimens and the multiple types of third specimens are linearly interpolated, and the strength ratios of the second specimens and third specimens that have undergone similar drying are also linearly interpolated to create a strength reduction model.

[0009] By linearly interpolating the strength ratios between the first specimen and multiple types of third specimens, the decrease in rock strength can be estimated according to any degree of saturation after drying. Similarly, by linearly interpolating the strength ratios between the second and third specimens that have undergone similar drying, the decrease in rock strength can be estimated according to any degree of saturation after immersion.

[0010] The deformation analysis apparatus for ground according to the present invention comprises an analysis model creation unit, a seepage flow analysis unit, an intensity ratio estimation unit, and a deformation analysis unit. The analysis model creation unit creates an analysis model of the ground. The seepage flow analysis unit performs a seepage flow analysis of the analysis model to determine the change in saturation due to drying and infiltration of the elements of the analysis model. The intensity ratio estimation unit inputs the change in saturation of the elements of the analysis model into the intensity reduction model in the rock intensity ratio estimation method described above to estimate the intensity ratio of the elements of the analysis model. The deformation analysis unit performs a deformation analysis of the analysis model using the intensity ratio of the elements of the analysis model.

[0011] The analysis model creation unit, seepage flow analysis unit, and intensity ratio estimation unit can estimate the intensity distribution based on changes in the saturation of the ground. The deformation analysis unit can accurately estimate the deformation of the ground due to groundwater flow, etc.

[0012] The deformation analysis unit uses the strength ratio of the elements of the analysis model to determine the cohesive force of the elements of the analysis model and then performs deformation analysis of the analysis model. This allows for accurate estimation of ground deformation.

[0013] In the ground deformation analysis method of the present invention, the computer of the ground deformation analysis device performs the following steps: analysis model creation step, seepage flow analysis step, intensity ratio estimation step, and deformation analysis step. The program of the present invention causes the computer of a ground deformation analysis device to perform the following steps: an analysis model creation step, a seepage flow analysis step, an intensity ratio estimation step, and a deformation analysis step. In the analysis model creation process, an analysis model of the ground is created. In the seepage flow analysis process, seepage flow analysis is performed on the analysis model to determine the change in saturation due to drying and infiltration of the elements of the analysis model. In the strength ratio estimation process, the change in saturation of the elements of the analysis model is input into the strength reduction model in the rock strength ratio estimation method described above to estimate the strength ratio of the elements of the analysis model. In the deformation analysis process, deformation analysis of the analysis model is performed using the strength ratio of the elements of the analysis model.

[0014] The analysis model creation process, seepage flow analysis process, and intensity ratio estimation process allow for the estimation of the intensity distribution based on changes in the saturation of the ground. The deformation analysis process using the estimated intensity distribution allows for the accurate estimation of ground deformation due to groundwater flow, etc. [Effects of the Invention]

[0015] The rock strength ratio estimation method of the present invention allows for accurate estimation of the decrease in rock strength. The deformation analysis device, deformation analysis method, and program for ground formation of the present invention enable accurate estimation of ground formation deformation.

Brief Description of the Drawings

[0016] [Figure 1] A graph showing the relationship between air drying time and uniaxial compressive strength. [Figure 2] A graph showing the relationship between the saturation of the specimen after drying and the strength ratio after immersion in water. [Figure 3] A graph of the rock strength reduction model. [Figure 4] A block diagram of the in-situ deformation analysis device. [Figure 5] A flowchart of the in-situ deformation analysis method. [Figure 6] An explanatory diagram of the analysis model.

Modes for Carrying Out the Invention

[0017] Hereinafter, the rock strength ratio estimation method, in-situ deformation analysis device, in-situ deformation analysis method, and program according to the embodiments will be described with reference to the drawings. Some rocks fragmentize after being immersed in water after drying. This phenomenon is called slaking. It is known that Neogene argillaceous soft rocks are particularly prone to slaking. A mechanism has been proposed in Non-Patent Document 4 that deformation of the in-situ rock mass occurs due to a reduction in strength caused by slaking of the rocks constituting the in-situ rock mass.

[0018] In the embodiments, a rock test is performed on the rocks constituting the in-situ rock mass. Hereinafter, as an example of the rock test results (referred to as test examples), the test results of rocks collected from a Neogene mudstone in-situ rock mass are shown. Based on the results of the rock test, a strength reduction model for the target rock is created. Next, numerical analysis is performed using an analysis model that simulates the target in-situ rock mass. The numerical analysis consists of seepage flow analysis and deformation analysis. Some of the physical property values used in the deformation analysis are determined from the output results of the seepage flow analysis and the strength reduction model. This series of numerical analysis is loaded into a computer with a monitor or the like as a numerical analysis program executable by a computer, and functions under the control of the computer.

[0019] (Rock testing, rock strength degradation model) To conduct rock testing, rock specimens are prepared. The rock is collected from the ground that will be the subject of the deformation analysis. The rock collected should be in its natural water content state and approximately saturated. By collecting the rock from a position below the groundwater level, it is possible to collect rock that is approximately saturated. From the collected rock, cylindrical specimens are prepared.

[0020] For the first test specimen, a first test is performed to determine the uniaxial compressive strength (sometimes simply referred to as strength) (first test process). In measuring the uniaxial compressive strength, a compressive load is applied to the axial end face of the specimen using a compression testing machine. The uniaxial compressive strength is determined by dividing the maximum load applied until the specimen breaks by the area of ​​the end face of the specimen. Figure 1 is a graph showing the relationship between air-drying time and unconfined compressive strength. Specimen 1 represents the case with natural moisture content and no immersion. In this test example, the unconfined compressive strength of specimen 1 is 4.8 MPa.

[0021] The water content of the first specimen is determined. The water content is calculated by dividing the mass of water contained in the specimen by the mass of rock in the specimen. The mass of water contained in the specimen is obtained by subtracting the mass of rock in the specimen from the total mass of the specimen. The mass of rock in the specimen is the mass of the specimen after it has been almost completely dried (absolutely dried). The total mass of the first specimen and the mass after absolute drying are measured using the first specimen after the uniaxial compressive strength measurement. Alternatively, the total mass and the mass after absolute drying may be measured using a different first specimen than the one used for the uniaxial compressive strength measurement.

[0022] A second specimen is prepared by drying the test specimen. For example, the test specimen is kept in a predetermined temperature and humidity environment for a predetermined time to dry (air-dry) it. Multiple types of second specimens are prepared by drying the test specimen to multiple degrees of dryness. In the test example shown in Figure 1, three types of second specimens are prepared by drying the test specimen to three different degrees of dryness. The three degrees of dryness are air-drying for 8 hours, air-drying for 72 hours, and oven-drying.

[0023] The uniaxial compressive strength of three types of second specimens is determined. In the test example shown in Figure 1, the second specimen is subjected to no water immersion. The uniaxial compressive strength of the second specimen is 5.7 MPa after air drying for 8 hours, 10.5 MPa after air drying for 72 hours, and 13.1 MPa after complete drying.

[0024] A second test is conducted to determine the moisture content of the second specimen (second test step). The moisture content is measured using the second specimen after the unconfined compressive strength measurement. Alternatively, the moisture content may be measured using a second specimen different from the one measured after the unconfined compressive strength measurement. The moisture content of the second specimen is normalized by dividing it by the moisture content of the first specimen. As mentioned above, the first specimen is approximately saturated, so the degree of saturation of the first specimen is assumed to be 1. In this case, the normalized moisture content of the second specimen can be considered as the degree of saturation. Therefore, the degree of saturation of the second specimen is determined by normalizing the moisture content of the second specimen by the moisture content of the first specimen.

[0025] The first specimen is dried in the same way as the second specimen, and then immersed in water to create the third specimen. During immersion, the specimen is kept in water for a long time until the change in mass of the specimen is almost negligible. The degree of saturation of the third specimen after immersion can be considered to be 1. Multiple types of third specimens are created by drying multiple types of second specimens in the same way, and then immersing them in water. In the test example shown in Figure 1, three types of third specimens are created by drying the specimens to three different degrees of dryness and then immersing them in water. The degrees of saturation of the three types of third specimens after drying (before immersion) can be considered to be the same as the degrees of saturation of the three types of second specimens.

[0026] A third test is conducted to determine the uniaxial compressive strength of the third specimen (third test procedure). In the test example shown in Figure 1, the third specimen is subjected to immersion in water. The uniaxial compressive strength of the third specimen is 0.7 MPa when immersed in water after 8 hours of air drying. The uniaxial compressive strength is 0.0 MPa when immersed in water after 72 hours of air drying and when immersed in water after complete drying.

[0027] The strength ratio of the third specimen to the strength of the first specimen is determined. The strength ratio of the third specimen is the value obtained by dividing the uniaxial compressive strength of the third specimen after immersion by the uniaxial compressive strength of the first specimen before immersion. As mentioned above, the uniaxial compressive strength of the first specimen before immersion in the test example is 4.8 MPa. The strength ratio of the third specimen after immersion is 0.15 after air drying for 8 hours, and 0.0 after air drying for 72 hours and after complete drying.

[0028] For comparison, the uniaxial compressive strength of the first specimen after immersion is determined. The first specimen was not dried at its natural moisture content, so it corresponds to the case where the specimen was air-dried for 0 hours. In the test example shown in Figure 1, the first specimen after immersion is the case with immersion at its natural moisture content. In the test example, the uniaxial compressive strength of the first specimen after immersion is 5.8 MPa. Since the uniaxial compressive strength of the first specimen after immersion is equivalent to the uniaxial compressive strength before immersion, we assume that the strength ratio of the first specimen after immersion is 1.

[0029] Figure 2 is a graph showing the relationship between the degree of saturation after drying of the specimen and the strength ratio after drying and immersion. Specimen 1 corresponds to being air-dried for 0 hours from a saturated state, so its degree of saturation after drying is 1. The degree of saturation after drying (before immersion) of specimen 3 is 0.8 after air-drying for 8 hours, 0.4 after air-drying for 72 hours, and 0.0 after complete drying.

[0030] Let w be the degree of saturation of the specimen after drying, and q be the strength ratio after drying and immersion. * As shown in Figure 2, (w,q * We assume that the plot of ) changes linearly. That is, we linearly interpolate between the intensity ratios of the first specimen and multiple types of third specimens. This allows us to * is a function of w q * It can be organized as (w).

[0031] Incidentally, Figure 1 shows that the uniaxial compressive strength increases upon drying of the specimen. However, the decrease in uniaxial compressive strength due to immersion in water after drying is more significant. Therefore, we assume that the uniaxial compressive strength of the specimen after drying is equal to the uniaxial compressive strength of the specimen before drying (i.e., the first specimen with its natural moisture content). In other words, we assume that the strength ratio of the second specimen after drying is 1.

[0032] As mentioned above, the following assumptions (1) to (3) are made regarding the results of the obtained test examples. (1) The degree of saturation of the specimen before drying (first specimen) is 1. (2) The uniaxial compressive strength of the specimen after drying is equal to the uniaxial compressive strength of the specimen at its natural moisture content. (3) The degree of saturation of the specimen (third specimen after immersion) during the uniaxial compression test is 1.

[0033] By assumption (1), w can be considered as the degree of saturation after drying (0 ≤ w ≤ 1). Furthermore, by assuming (3) above, q * (w) can be considered as the strength ratio to the initial uniaxial compressive strength when the saturation of the specimen changes from 1 to w to 1.

[0034] Furthermore, we assume the following (4): (4) During the immersion process after drying, the uniaxial compressive strength decreases in proportion to the degree of saturation until the degree of saturation reaches 1. As mentioned above, the saturation degree of the second specimen after drying is less than 1, and the intensity ratio is 1. On the other hand, the saturation degree of the third specimen after immersion is 1, and the intensity ratio is less than 1. During the immersion process of the third specimen, the saturation degree rises from less than 1 to 1. During this time, we assume that the intensity ratio of the third specimen decreases linearly from 1 to less than 1. That is, we linearly interpolate between the intensity ratios of the second and third specimens that have undergone similar drying processes.

[0035] Here, Q(w,w') represents the strength ratio to the initial uniaxial compressive strength when a rock that was initially saturated dries to an arbitrary degree of saturation w, and then recovers to an arbitrary degree of saturation w' (w≦w'≦1) through subsequent flooding. Then, by assuming all of the above (1)~(4), the following relationship holds.

[0036]

number

[0037] Expanding equation 1, Q(w,w') can be expressed by the following equation 2.

[0038]

number

[0039] Equation 2 is a model equation that can estimate the degree of rock strength reduction for any change in saturation during drying and subsequent flooding. This strength reduction model shows the relationship between the minimum saturation of the rock during drying, the maximum saturation of the rock during flooding after drying, and the rock strength ratio.

[0040] Figure 3 is a graph of a rock strength reduction model. The horizontal axis of Figure 3 represents the degree of saturation w after drying, and the vertical axis represents the degree of saturation w' after water immersion following drying. In Figure 3, the intensity of the shading indicates the magnitude of the rock strength ratio Q(w,w'). The point (w,w')=(1,1) in the upper left of Figure 3 represents the initial state of the rock (natural water content), where the strength ratio Q is 1. For example, if the degree of saturation w after drying is 0.5 and the degree of saturation w' after water immersion is 0.85, it can be seen that the strength ratio Q decreases to approximately 0.4.

[0041] (Numerical analysis) By using this strength reduction model and executing a numerical analysis program consisting of seepage flow analysis and deformation analysis processes on a computer, the displacement of the ground whose strength has decreased in accordance with the change in saturation level can be determined.

[0042] Figure 4 is a block diagram of the ground deformation analysis device 1. The ground deformation analysis device 1 includes an analysis model creation unit 10, a seepage flow analysis unit 20, an intensity ratio estimation unit 30, a deformation analysis unit 40, and a memory unit 50.

[0043] Of the components of the deformation analysis device 1, all components except the memory unit 50 are realized by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of the functions of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), or GPU (Graphics Processing Unit), or by the cooperation of software and hardware. Some or all of the functions of these components may be realized by a dedicated LSI. The program may be stored in advance in a storage device (a storage device with a non-transient storage medium) such as an HDD (Hard Disk Drive) or flash memory provided by the deformation analysis device 1, or it may be stored in a removable storage medium (a non-transient storage medium) such as a DVD or CD-ROM, and installed in the storage device of the deformation analysis device 1 when the storage medium is mounted in a drive device provided by the deformation analysis device 1. The deformation analysis device 1 may be realized in a computer device or storage device such as a personal computer.

[0044] Figure 5 is a flowchart of the deformation analysis method for the ground. In the deformation analysis method for the ground, the computer of the deformation analysis device 1 executes the analysis model creation process S10, the seepage flow analysis process S20, the intensity ratio estimation process S30, and the deformation analysis process S40. The program causes the computer of the deformation analysis device 1 to execute the analysis model creation process S10, the seepage flow analysis process S20, the intensity ratio estimation process S30, and the deformation analysis process S40.

[0045] FIG. 6 is an explanatory diagram of the analysis model. First, the analysis model creation unit 10 creates an analysis model of the ground (analysis model creation step S10). Specifically, it simulates the target ground and creates an analysis model in which the analysis area is divided into a large number of elements. The analysis model creation unit 10 requests the operator to input information necessary for creating the analysis model. The analysis model creation unit 10 creates an analysis model according to the information input by the operator.

[0046] Next, the seepage flow analysis unit 20 performs seepage flow analysis (seepage flow analysis step S20). In the seepage flow analysis step, the change in saturation during the process of the target ground reabsorbing water after drying is obtained by saturated-unsaturated analysis. First, conditions such as physical property values, unsaturated characteristics, and analysis conditions are set for the analysis model (S22). The physical property values and unsaturated characteristics are set according to the type of rock. The physical property values are the saturated hydraulic conductivity, specific storage coefficient, porosity, etc. The unsaturated characteristics are the relationship between the relative hydraulic conductivity and the negative pressure head with respect to saturation. The analysis conditions are the initial conditions, boundary conditions, etc. Then, the analysis is executed (S24) and the results are output (S26). As the analysis results, for each element i of the analysis model (see FIG. 6), the saturation w i that decreases most due to drying i and the saturation w'

[0047] that increases most due to subsequent reabsorption i are output. i Next, the strength ratio estimation unit 30 estimates the strength ratio of each element i (strength ratio estimation step S30). In the storage unit 50 of the ground deformation analysis device 1 shown in FIG. 4, the above-described rock strength reduction model is stored. The strength ratio estimation unit 30 requests the operator to input information regarding the type of rock. The strength ratio estimation unit 30 reads out the strength reduction model corresponding to the input rock type from the storage unit 50. The strength ratio estimation unit 30 inputs the change in saturation (w i , w' i ) of each element i output by the seepage flow analysis into the strength reduction model. Thereby, the strength ratio Q i (w

[0048] Next, the deformation analysis unit 40 performs deformation analysis of the ground using the finite difference method or the like (deformation analysis process S40). First, conditions such as physical properties and analysis conditions are set (S42). The physical properties are set according to the type of rock. The physical properties include unit weight, elastic modulus, Poisson's ratio, cohesion, internal friction angle, and dilectancy angle. The analysis is performed under these conditions to determine the displacement of each element in the equilibrium state. Here, the cohesion c0 of the ground in a separately set natural water content state and the strength ratio Q obtained based on the results of the seepage flow analysis are used. i The product of this result in the decrease in the adhesion force c of each element i due to the change in saturation. i We will find the adhesive strength c. i These are input as the material properties of each element i in the deformation analysis. Then, the analysis is run again (S44), and the results are output (S46). As an analysis result, the displacement of the nodes of each element in the equilibrium state is output. This makes it possible to analytically obtain the displacement of the ground whose strength has decreased due to the change in saturation.

[0049] As detailed above, the rock strength ratio estimation method of the embodiment comprises a first test step, a second test step, a third test step, a strength reduction model creation step, and a strength ratio estimation step. In the first test step, the strength of the first specimen, which is a rock specimen, is determined. In the second test step, the specimen is dried to create a second specimen, and the saturation of the second specimen is determined assuming that the saturation of the first specimen is 1. In the third test step, the specimen is dried in the same way as the second specimen and then immersed in water to create a third specimen, and the strength of the third specimen is determined, as well as the strength ratio of the third specimen to the strength of the first specimen. In the strength reduction model creation step, the strength ratio of the second specimen to the strength of the first specimen is assumed to be 1, and the saturation of the third specimen is assumed to be 1. Then, using the saturation and strength ratios of the second and third specimens, a strength reduction model is created that shows the relationship between the change in saturation due to rock drying and immersion and the strength ratio of the rock to the strength of the first specimen. In the strength ratio estimation process, the change in saturation due to rock drying and immersion is input into the strength reduction model to estimate the strength ratio of the rock.

[0050] By creating a strength reduction model based on rock testing, the strength reduction of rocks can be estimated with high accuracy. Furthermore, a strength reduction model is created that shows the relationship between changes in saturation due to rock drying and immersion and the rock's strength ratio. This allows for accurate estimation of the strength reduction of rocks exhibiting slaking properties.

[0051] In the second testing step, the specimens are dried to multiple degrees of dryness to create multiple types of second specimens, and the degree of saturation of these multiple types of second specimens is determined. In the third testing step, the specimens are dried in the same manner as the multiple types of second specimens, and then immersed in water to create multiple types of third specimens, and the strength ratio of these multiple types of third specimens is determined. In the strength reduction model creation step, the strength ratios of the first specimens and the multiple types of third specimens are linearly interpolated, and the strength ratios of the second specimens and third specimens that have undergone similar drying are also linearly interpolated to create a strength reduction model.

[0052] By linearly interpolating the strength ratios between the first specimen and multiple types of third specimens, the decrease in rock strength can be estimated according to any degree of saturation after drying. Similarly, by linearly interpolating the strength ratios between the second and third specimens that have undergone similar drying, the decrease in rock strength can be estimated according to any degree of saturation after immersion.

[0053] The deformation analysis device 1 of the embodiment includes an analysis model creation unit 10, a seepage flow analysis unit 20, an intensity ratio estimation unit 30, and a deformation analysis unit 40. In the deformation analysis method for the ground according to this embodiment, the computer of the ground deformation analysis device 1 performs the following steps: analysis model creation step, seepage flow analysis step, intensity ratio estimation step, and deformation analysis step. The program of this embodiment causes the computer of the ground deformation analysis device 1 to perform the following steps: analysis model creation, seepage flow analysis, intensity ratio estimation, and deformation analysis.

[0054] In the analysis model creation process, an analysis model of the ground is created. In the seepage flow analysis process, seepage flow analysis is performed on the analysis model to determine the change in saturation due to drying and infiltration of the elements of the analysis model. In the strength ratio estimation process, the change in saturation of the elements of the analysis model is input into the strength reduction model in the rock strength ratio estimation method described above to estimate the strength ratio of the elements of the analysis model. In the deformation analysis process, deformation analysis of the analysis model is performed using the strength ratio of the elements of the analysis model.

[0055] The analysis model creation process, seepage flow analysis process, and intensity ratio estimation process allow for the estimation of the intensity distribution based on changes in the saturation of the ground. The deformation analysis process using the estimated intensity distribution allows for accurate estimation of ground deformation due to groundwater flow, etc. The ground deformation analysis device 1, ground deformation analysis method, and program of this embodiment can be used for future prediction of deformation in mountain tunnels and design of countermeasures.

[0056] The deformation analysis unit uses the strength ratio of the elements of the analysis model to determine the cohesive force of the elements of the analysis model and then performs deformation analysis of the analysis model. This allows for accurate estimation of ground deformation.

[0057] Although one embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and modifications, combinations, deletions, etc., of the configuration are also included without departing from the spirit of the present invention. [Explanation of Symbols]

[0058] 1...Ground deformation analysis device, 10...Analysis model creation unit, 20...Seepage flow analysis unit, 30...Strength ratio estimation unit, 40...Deformation analysis unit.

Claims

1. The first test process involves determining the strength of the first specimen, which is a rock specimen, and A second test step involves drying the aforementioned specimen to prepare a second specimen, and assuming the degree of saturation of the first specimen is 1, determining the degree of saturation of the second specimen. A third test step involves drying the aforementioned specimen in the same manner as the second specimen, then immersing it in water to create a third specimen, determining the strength of the third specimen, and determining the strength ratio of the third specimen to the strength of the first specimen. A strength reduction model creation step involves creating a strength reduction model that shows the relationship between the change in saturation due to drying and immersion of the rock and the strength ratio of the rock to the strength of the first specimen, based on the saturation and strength ratio of the second and third specimens, assuming that the strength ratio of the second specimen to the strength of the first specimen is 1, and assuming that the degree of saturation of the third specimen is 1. The system includes a strength ratio estimation step, which involves inputting the change in saturation due to drying and soaking of the rock into the strength reduction model to estimate the strength ratio of the rock. Method for estimating the strength ratio of rocks.

2. In the second test step, the specimen is dried to multiple degrees of dryness to create multiple types of second specimens, and the degree of saturation of the multiple types of second specimens is determined. In the third test step, the specimen is dried in the same manner as the multiple types of second specimens, then immersed in water to create multiple types of third specimens, and the strength ratio of the multiple types of third specimens is determined. In the process of creating the strength reduction model, the strength ratios of the first specimen and the multiple types of third specimens are linearly interpolated, and the strength ratios of the second specimen and the third specimen that have undergone similar drying are linearly interpolated to create the strength reduction model. The method for estimating the strength ratio of rocks according to claim 1.

3. The analysis model creation unit creates an analysis model of the ground, A seepage flow analysis unit performs seepage flow analysis on the aforementioned analytical model to determine the change in saturation due to drying and immersion of the elements of the analytical model, A strength ratio estimation unit that inputs the change in the degree of saturation of the elements of the analysis model into the strength reduction model in the rock strength ratio estimation method according to claim 1 or 2, and estimates the strength ratio of the elements of the analysis model, A deformation analysis unit that performs deformation analysis of the analysis model using the intensity ratio of the elements of the analysis model, A device for analyzing the deformation of natural ground.

4. The deformation analysis unit uses the strength ratio of the elements of the analysis model to determine the adhesive force of the elements of the analysis model and performs deformation analysis of the analysis model. The deformation analysis apparatus for ground according to claim 3.

5. The computer in the ground deformation analysis device, The process of creating an analytical model for the ground, A seepage flow analysis step is performed on the aforementioned analytical model to determine the change in saturation due to drying and immersion of the elements of the analytical model, An element strength ratio estimation step is performed by inputting the change in the degree of saturation of the elements of the analysis model into the strength reduction model in the rock strength ratio estimation method according to claim 1 or 2, and estimating the strength ratio of the elements of the analysis model. A deformation analysis step is performed, in which deformation analysis of the analysis model is performed using the intensity ratio of the elements of the analysis model. Methods for analyzing deformation of natural ground.

6. The computer in the ground deformation analysis device, The process of creating an analytical model for the ground, A seepage flow analysis step is performed on the aforementioned analytical model to determine the change in saturation due to drying and immersion of the elements of the analytical model, An element strength ratio estimation step is performed by inputting the change in the degree of saturation of the elements of the analysis model into the strength reduction model in the rock strength ratio estimation method according to claim 1 or 2, and estimating the strength ratio of the elements of the analysis model. A deformation analysis step is performed, in which deformation analysis of the analysis model is carried out using the intensity ratio of the elements of the analysis model. program.

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