JP4913547B2 - Geological prediction method of natural ground - Google Patents

Description

  The present invention relates to a geological evaluation method for natural ground.

  Conventionally, in mountain tunnel construction, the geological condition of the face has been determined in order to appropriately select the excavation method and support pattern. To determine the geological condition of the face, the “face evaluation method” has been used in which an experienced engineer observes the face rock and scores the observation results.

In addition, the geological situation ahead of the face has been predicted. Jumbos commonly used for tunnel excavation are equipped with hydraulic percussion drills. Prediction of geological conditions has been performed by drilling from the face to the front by about 30 to 50 m using this drill and obtaining various drilling data according to the drilling depth.

As a prediction method of geological situation using drilling data, (1) Calculate “Fracture energy coefficient” from drilling data (instant drilling speed, hitting energy, number of hits, hole cross-sectional area at drilling depth), There was a method of estimating the rock mass by associating the rock mass grade with the failure energy coefficient by a probabilistic and statistical method, and predicting the geology ahead of the face. (For example, refer to Patent Document 1).

  In addition, as a similar technology, (2) a lot of drilling data (feed pressure, impact pressure, bit wear, etc.) is measured, and the “standard drilling speed” and “standard rotational pressure” are obtained. There has been a method of obtaining a converted elastic wave velocity by correlation with the above and quantitatively evaluating the natural ground based on the conventional natural ground classification (see, for example, Patent Document 2).

In addition, (3) the hardness of the geology is determined by plotting the average value of “bit rotation speed” obtained by drilling on the ground strength judgment chart. From the result of analyzing the frequency components generated by small fluctuations in the rocks, it is possible to judge the amount of gravel in soft rock, and if there is little gravel, there is a method to judge whether it is muddy or sandy from the turbidity of drilling water (For example, see Patent Document 3).

Furthermore, (4) there is also a method of predicting geological properties by calculating “drilling energy” according to the drilling depth from the drilling data (blowing energy, number of hits per unit time, drilling speed, hole cross-sectional area). (For example, see Patent Document 4).

JP-A-4-161588 JP-A-8-144682 Japanese Patent Laid-Open No. 10-252051 JP 2002-13381 A

However, in the conventional method (1), there are many examples in which the natural ground situation cannot be evaluated appropriately. FIG. 7 is a graph of the prediction result of the geological situation by the method (1). In FIG. 7, the horizontal axis indicates the distance, and the vertical axis indicates the face evaluation point and the fracture energy coefficient. Although the fracture energy coefficient is obtained for each drilling depth, it is more accurate to represent the geological condition of the natural ground if it is handled as data with a certain width. ing.

In the result shown in FIG. 7, the variation of the fracture energy coefficient 201 is large, the correlation coefficient with the face evaluation point 203 is 0.3, and it seems that the actual ground condition is not properly evaluated. In the method (1), the formula combining the individual drilling data is uniquely defined as the “fracture energy coefficient” to evaluate the natural ground, and the difference in contribution of each data due to geology It is thought that it is not considered.

This invention is made | formed in view of such a problem, The place made into the objective is to provide the geological evaluation method of the natural ground which can predict the geological condition ahead of a face with high precision.

In order to achieve the above-described object, the present invention provides a step (a) of acquiring a plurality of types of drilling data ahead of a face in a ground excavated portion, and acquiring geological information in the ground excavated portion. Step (b), analyzing the drilling data by multivariate analysis, creating a first geological prediction formula, the geological information calculated using the first geological prediction formula, and the Adjusting the fluctuation range with the geological information acquired in the step (b) to create a second geological prediction formula, and in the unexcavated portion of the natural ground, drilling data ahead of the face Using the step (e) to be acquired, the first geological prediction formula and the second geological prediction formula, and the drilling data acquired in the step (e), the geological information in the unexcavated portion of the natural ground geological prediction method of the natural ground, characterized by comprising a step (f) to predict the A.

The drilling data acquired in step (a) drilling data and process acquired in (e) is the same kind, drilling speed, striking hammer pressure, torque, that a number of Chi sac feed pressure or the like desired . Moreover, it is desirable that the geological information acquired in the step (b) is any one of a face evaluation point, uniaxial compressive strength, elastic modulus, elastic wave velocity, and the like. The geological information predicted in the step (f) is the same type as the geological information acquired in the step (b).

  In the present invention, a plurality of types of drilling data ahead of the face are acquired in an already excavated part of a natural ground. Also, before and after the drilling data is acquired, the geological information in the already excavated part of the natural ground is acquired. And after analyzing the drilling data in the existing excavation part by multivariate analysis and creating the first geological prediction formula, the geological information calculated using the first geological prediction formula and the geological information in the existing excavation part The second geological prediction formula is created by adjusting the fluctuation range. Furthermore, in the unexcavated part of the natural ground, drilling data in front of the face is obtained, and the ground data is obtained by using the first geological prediction formula and the second geological prediction formula and the drilling data in the unexcavated part of the natural ground. Predict geological information in unexcavated parts of the mountain.

  ADVANTAGE OF THE INVENTION According to this invention, the geological evaluation method of the natural ground which can predict the geological condition ahead of a face with high precision can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a cross-sectional view of the natural ground 1 around the tunnel 3 during excavation, FIG. 2 is a hardware configuration diagram of the server 31, and FIG. 3 is a flowchart of the geological evaluation method for natural ground according to the present embodiment. Show.

  In the present embodiment, the geological evaluation method shown in the flowchart of FIG. 3 uses the system shown in FIG. 2, and the geological situation of the ground 1 around the tunnel 3 shown in FIG. Predict geological conditions.

  Next, the hardware configuration of the server 31 will be described. The server 31 is configured by connecting a control unit 33, a storage unit 35, a media input / output unit 37, a communication control unit 39, an input unit 41, a display unit 43, a printing unit 45, and the like via a system bus 47.

The control unit 33 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random).
Access Memory).

The CPU calls and executes a program stored in the storage unit 35, ROM, recording medium or the like to a work memory area on the RAM, and drives and controls each device connected via the system bus 47. The ROM is a non-volatile memory and permanently stores programs, data, and the like. The RAM is a volatile memory, and temporarily holds a program, data, and the like loaded from the storage unit 35, ROM, recording medium, and the like, and includes a work area used by the control unit 33 for performing various processes.

The storage unit 35 is an HDD (hard disk drive), and stores a program executed by the control unit 33, data necessary for program execution, an OS (operating system), and the like. Each program code is read by the control unit 33 as necessary, transferred to the RAM, read by the CPU, and executed as various means.

The media input / output unit 37 (drive device) performs data input / output, for example, floppy disk drive, PD drive, CD drive (-ROM, -R, -RW, etc.), DVD drive (-ROM, -R, etc.). -RW etc.) and media input / output devices such as MO drives.

The communication control unit 39 includes a communication control device, a communication port, and the like, and is a communication interface that mediates communication between the server 31 and the network 49. Via the network 49, the server 31 and a client terminal (not shown) Control communication between the two.

The input unit 41 includes, for example, a keyboard, a pointing device such as a mouse, and an input device such as a numeric keypad. An operation instruction, an operation instruction, data input, and the like can be performed on the server 31 via the input unit 41. The display unit 43 is a display device such as a CRT monitor or a liquid crystal panel. The printing unit 45 is a printer and performs print output processing. The system bus 47 is a path that mediates transmission / reception of control signals, data signals, and the like between the devices.

As shown in FIG. 3, the geological evaluation method includes steps for analyzing the already excavated portion 5 of the tunnel 3 (steps 101 to 105) and steps for predicting the unexcavated portion 7 (steps 106 to 106). Step 108). Steps other than Step 101, Step 103, and Step 106 shown in FIG. 3 are performed by the control unit 33 of the server 31 according to an execution program stored in the storage unit 35 and the like.

In the geological evaluation method shown in FIG. 3, first, the already excavated portion 5 of the tunnel 3 is analyzed. In the analysis of the already excavated part 5, first, the drilling speed 11 and the striking pressure 13 of the already excavated part 5 of the natural ground 1 are obtained (step 101). In step 101, the drilling speed 11 and the striking pressure 13 are obtained for the already excavated portion 5 of the tunnel 3 being excavated according to the distance. The drilling speed 11 and the impact pressure 13 are drilling data when the hole 10a is drilled in the face 9a. In step 101, the drilling speed 11 and the striking pressure 13 are stored in the storage unit 35, for example, by an operator inputting via the media input unit 37, the input unit 41, or the like.

Then, the average value, standard deviation, and ratio of the drilling speed 11 and the impact pressure 13 are calculated (step 102). In step 102, the control unit 33 uses the drilling speed 11 obtained in step 101 to calculate the average value, standard deviation, and ratio between the average value and the standard deviation of the drilling speed 11. Also, using the striking pressure 13 obtained in step 101, the average value, standard deviation, and ratio of the mean value and standard deviation of the striking pressure 13 are calculated.

In parallel with Step 101 and Step 102, a face evaluation score 15 of the already excavated portion 5 of the tunnel 3 is obtained (Step 103). In step 103, the face evaluation point 15 is obtained by observing the face 9 a of the already excavated portion 5 using the conventional face evaluation point method. The face evaluation score 15 is geological information of the already excavated part 5. In step 103, for example, the face evaluation score 15 is stored in the storage unit 35, for example, by an operator inputting via the media input unit 37, the input unit 41, or the like.

Next, multivariate analysis is performed to create a prediction formula (Formula 1) of the natural ground evaluation point (A) (Step 104). In Step 104, the control unit 33 calculates the average value μ _Vp of the drilling speed 11 calculated in Step 102, the standard deviation σ _Vp , the ratio between the average value and the standard deviation (μ / σ) _Vp , and the average value μ of the impact pressure 13. Multivariate analysis is performed using _Pp , standard deviation σ _Pp , ratio of average value and standard deviation (μ / σ) _Pp, and a prediction formula (Formula 1) of the natural ground evaluation point (A) is created. The prediction formula (Formula 1) of the natural ground evaluation point (A) is a first geological prediction formula. In the example of the natural ground 1 around the tunnel 3 shown in FIG. 1, the following (Formula 1) was obtained.

Evaluation point of natural ground (A) = − 0.261 × μ _Vp + 0.270 × σ _Vp + 0.9549 × (μ / σ) _Vp + 0.009 × μ _Pp + 0.230 × (μ / σ) _Pp + 16.643 ......... (Formula 1)

In step 104, the control unit 33 calculates a natural ground evaluation point (A) according to the distance of the already excavated unit 5 using (Equation 1). FIG. 4 shows the evaluation result of the geological situation of the natural ground 1 calculated in step 104. In step 104, the control unit 33 outputs the evaluation result of the geological situation shown in FIG. 4 to the display unit 43 and the printing unit 45 as necessary.

The horizontal axis in FIG. 4 indicates the distance, and the vertical axis indicates the natural ground evaluation point. In FIG. 4, the face evaluation score obtained in step 103 is the actual natural ground evaluation score 23. As shown in FIG. 4, the natural ground evaluation point (A) 21 calculated in step 104 and the actual natural ground evaluation point 23 have a correlation coefficient of 0.5, and are predicted by the conventional method shown in FIG. It turns out that the situation of natural ground 1 can be predicted with a higher correlation than the result.

However, in FIG. 4, when comparing the standard deviation of the actual natural ground evaluation point 23 with the standard deviation of the calculated natural ground evaluation point (A) 21, the standard deviation of the actual natural ground evaluation point 23 is 10. The standard deviation of the calculated natural ground evaluation point (A) 21 is as small as 4.579. For this reason, the calculated natural ground evaluation point (A) 21 only varies in the vicinity of the average value, and it cannot be said that the situation of the natural ground 1 is accurately evaluated.

Next, the fluctuation range is adjusted to create a prediction formula (Formula 2) for the natural ground evaluation point (B) (Step 105). In step 105, the control unit 33 matches the actual fluctuation range (standard deviation) of the natural ground evaluation point 23 shown in FIG. 4 with the calculated fluctuation range (standard deviation) of the natural ground evaluation point (A) 21. A prediction formula (Formula 2) of the geological evaluation point (B) is created. The prediction formula (Formula 2) of the geological evaluation point (B) is a second geological prediction formula. In (Expression 2), σ represents a standard deviation and μ represents an average value. Further, represents a (subscript) _real is an actual natural ground evaluation points (subscript) _multivariate natural ground evaluation points calculated by multivariate analysis (A).

Natural mountain evaluation point (B) = σ _real / σ _multivariate × (natural mountain evaluation point (A) −μ _multivariate ) + μ _real (Equation 2)

Below, each item of (Formula 2) is demonstrated. The (natural ground evaluation point (A) −μ _multivariate ) is a difference between the input value of the natural ground evaluation point (A) and the average value of the calculated natural ground evaluation point (A) 21, and is an example shown in FIG. 4. Then, it becomes (natural mountain evaluation point (A) -49.313).

σ _real / σ _multivariate is the ratio of the standard deviation of the actual natural ground evaluation point 23 and the standard deviation of the natural ground evaluation point (A) 21 calculated. Thereby, the fluctuation range from the average value of the calculated natural ground evaluation point (A) 21 can be matched with the fluctuation range from the average value of the actual natural ground evaluation point 23. In the example shown in FIG. 4, σ _real / σ _multivariate = 10.1047 / 4.579 = 2.216.

+ Mu _actual is the actual average value of the natural ground evaluation point 23. As shown in (Expression 2), a natural ground evaluation point (B) is obtained by adding this item to σ _actual / σ _multivariate × (natural ground evaluation point (A) −μ _multivariate ). In the example shown in FIG. 4, μ _real = 49.313.

  In step 105, the control unit 33 calculates a natural ground evaluation point (B) according to the distance of the already excavated unit 5 using (Equation 2). FIG. 5 shows the evaluation result of the geological situation of the natural ground 1 calculated using (Equation 2). In step 105, the control unit 33 outputs the evaluation result of the geological situation shown in FIG. 5 to the display unit 43 and the printing unit 45 as necessary.

In FIG. 5, the horizontal axis indicates the distance, and the vertical axis indicates the natural ground evaluation point. Also in FIG. 5, the face evaluation score obtained in step 103 is set as an actual natural ground evaluation score 23. As shown in FIG. 5, the natural ground evaluation point (B) 25 calculated by adjusting the fluctuation range according to (Equation 2) matches the actual natural ground evaluation point 23 very well.

After step 105, the unexcavated portion 7 of the tunnel 3 is predicted. In order to predict the unexcavated portion 7, first, the drilling speed 17 and the striking pressure 19 of the unexcavated portion 7 are obtained (step 106). In step 106, the operator drills a hole 10 in the unexcavated portion 7 of the tunnel 3 being excavated from the face 9 toward the front unexcavated portion 7. And according to distance, the drilling speed 17 and the impact pressure 19 which are drilling data are obtained. In step 106, the drilling speed 17 and the striking pressure 19 are stored in the storage unit 35 by, for example, an operator inputting via the media input unit 37, the input unit 41, and the like.

  Next, the ground evaluation point (A) of the unexcavated portion 7 is predicted using (Equation 1) (step 107). In step 107, the control unit 33 calculates an average value, a standard deviation, and a ratio between the average value and the standard deviation for the drilling speed 17 and the impact pressure 19 obtained in step 106, respectively. And the control part 33 estimates the natural ground evaluation point (A) of the unexcavated part 7 using the prediction formula (Formula 1) of the natural ground evaluation point (A) obtained at step 104. In step 107, the control unit 33 outputs the prediction result of the natural ground evaluation point (A) to the display unit 43 and the printing unit 45 as necessary.

  After Step 107, the ground evaluation point (B) of the unexcavated portion 7 is predicted using (Equation 2) (Step 108). In step 108, the control unit 33 uses the prediction formula (Equation 2) of the natural ground evaluation point (B) obtained in step 105 and the natural ground evaluation point (A) of the unexcavated portion 7 predicted in step 107. The fluctuation range of the face evaluation point 15 acquired in step 103 is adjusted, and the natural ground evaluation point (B) of the unexcavated portion 7 is predicted. In step 108, the control unit 33 outputs the prediction result of the natural ground evaluation point (B) to the display unit 43 and the printing unit 45 as necessary. The natural ground evaluation point (A) predicted in step 107 and the natural ground evaluation point (B) predicted in step 108 are geological information of the unexcavated portion 7.

  Thus, in this Embodiment, when analyzing the existing excavation part 5, the drilling speed 11 and the striking pressure 13 of the existing excavation part 5 are analyzed by multivariate analysis, and each data of the natural ground 1 is analyzed. The degree of contribution to the geology is quantitatively evaluated, and a prediction formula (Formula 1) of an appropriate natural ground evaluation point (A) is created. Furthermore, in order to adjust the fluctuation range between the natural ground evaluation point (A) calculated by (Equation 1) and the face evaluation point 15 of the already excavated part 5, a prediction formula (Equation 2) of the natural ground evaluation point (B) Create When the unexcavated portion 7 is predicted, the drilling speed 17 and the striking pressure 19 are acquired for the natural ground 1 of the unexcavated portion 7 and the ground of the natural ground 1 is obtained using (Expression 1) and (Expression 2). Predict mountain evaluation points (B).

Thereby, about the unexcavated part 7 ahead of the face 9, the actual face evaluation point 23 and the predicted natural ground evaluation point (B) 25 can be matched well. By predicting the geology of the ground 1 of the unexcavated portion 7 with high accuracy, it is possible to ensure the quality of the tunnel 3 and improve the safety of construction.

  The geological evaluation method is not limited to that shown in FIG. FIG. 6 is a diagram showing an outline of the geological evaluation method of the present invention. As shown in FIG. 6, the geological evaluation method of the present invention includes steps for analyzing the already excavated portion 5 of the tunnel 3 (step 201 to step 204) and steps for predicting the unexcavated portion 7 ( Step 205 to Step 207).

In this embodiment, as shown in FIG. 3, the drilling speed 11 and the striking pressure 13 are acquired as the drilling data of the already excavated part 5 in step 101, and the drilling data of the unexcavated part 7 is acquired in step 106. Although the hole speed 17 and the impact pressure 19 were acquired, in the geological evaluation method of the present invention, as shown in step 201 and step 205 in FIG. Some of speed, impact pressure, torque, feed pressure, etc. may be acquired. However, the drilling data acquired in step 201 and the drilling data acquired in step 205 are of the same type.

  Further, in the present embodiment, as shown in FIG. 3, the face evaluation score is acquired as the geological information of the already excavated portion 5 in Step 103, and the geological information of the unexcavated portion 7 is equivalent to the face evaluation score in Step 108. The natural ground evaluation point (B) has been predicted. However, in the geological evaluation method of the present invention, as shown in Step 202 and Step 207 in FIG. The geological information is any one of face evaluation points, uniaxial compressive strength, elastic modulus, elastic wave velocity, and the like. However, the geological information acquired in step 202 and the geological information predicted in step 205 are of the same type.

When analyzing the already excavated portion 5, in step 204, a first geological prediction formula (Formula 3) and a second geological prediction formula (Formula 4) are created. In step 204, first, a geological prediction formula (formula 3) for predicting the geological information (A) by performing multivariate analysis is created. Then, geological information (A) is calculated using (Equation 3). In (Expression 3), μ represents an average value, σ represents a standard deviation, and (subscript) _n represents a data type.

Geological information (A) = a × μ ₁ + b × σ ₁ + c × (μ / σ) ₁ + d × μ ₂ + e × σ ₂ + f × (μ / σ) ₂ + (Equation 3)

In step 204, after calculating the geological information (A), a geological prediction formula (formula for predicting the geological information (B) by adjusting the fluctuation range between the geological information (A) and the geological information acquired in step 202 is calculated. Create 4). In (Equation 4), representative of the (subscript) _actual practice of natural ground evaluation points (subscript) _multivariate geological information calculated by multivariate analysis (A).

Geological information (B) == sigma _real / sigma _multivariate × (geological information (A) - [mu] _{Multivariate)} + mu _actual ......... (Equation 4)

  When the unexcavated portion 7 is predicted, in step 206, the geological information (A) is predicted using (Equation 3), and then the fluctuation range is adjusted using (Equation 4) to adjust the geological information (B ).

  As shown in FIG. 6, when drilling data and geological information other than those shown in FIG. 3 are used, the drilling data is analyzed by multivariate analysis when analyzing the already excavated portion 5. An appropriate first geological prediction formula (Formula 3) is created, and the second geological prediction for adjusting the fluctuation range between the geological information calculated by (Formula 3) and the geological information acquired by the already excavated part 5 Formula (Formula 4) is created. When the unexcavated portion 7 is predicted, the drilling data is obtained for the natural ground 1 of the unexcavated portion 7 and the geological information of the natural ground is predicted using (Equation 3) and (Equation 4). . Thereby, for the unexcavated portion 7 in front of the face 9, the geological information well matched with the actual geological information can be predicted.

  As mentioned above, although preferred embodiment of the geological evaluation method of the natural ground concerning this invention was described referring an accompanying drawing, this invention is not limited to this example. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

Cross section of natural ground 1 around tunnel 3 during excavation Hardware configuration diagram of server 31 Flow chart of geological geological evaluation method Evaluation result of geological condition of natural ground 1 calculated using (Equation 1) Evaluation result of geological situation of natural mountain 1 calculated using (Equation 2) The figure which shows the outline | summary of the geological evaluation method of this invention Graph of prediction result of geological situation by conventional method

Explanation of symbols

1 ......... Mt. 3 ......... Tunnel 5 ......... Excavated part 7 ......... Unexcavated part 9, 9a ......... Face 10, 10, a ......... Hole 11, 17 ......... Drilling speed 13, 19 ... …… Blowing pressure 21, 25 ... …… Predicted face evaluation score (A)
23 ……… actual face evaluation score

Claims (4)

In the already excavated portion of the natural ground, a step (a) of acquiring a plurality of types of drilling data in front of the face,
A step (b) of acquiring geological information in the already excavated portion of the natural ground;
Analyzing the drilling data by multivariate analysis and creating a first geological prediction formula (c);
(D) creating a second geological prediction formula by adjusting the fluctuation range between the geological information calculated using the first geological prediction formula and the geological information acquired in the step (b);
In the unexcavated portion of the natural ground, a step (e) of acquiring drilling data in front of the face,
Using the first geological prediction formula and the second geological prediction formula and the drilling data acquired in the step (e), predicting the geological information in the unexcavated portion of the natural ground (f); ,
The geological prediction method of the natural ground characterized by comprising. A homologous and drilling data acquired in the drilling data and the step (e) which is obtained in the step (a), the drilling rate, hitting hammer pressure, torque, is the feed pressure or the like sac Chinoikutsuka The geological prediction method of a natural ground according to claim 1 . The geological information acquired in the step (b) is any one of a face evaluation point, a uniaxial compressive strength, an elastic coefficient, an elastic wave velocity, and the like. Geological prediction method. The geological information predicted in step (f) is, geological prediction method of the natural ground according to claim 1, characterized in that the geological information of the same kind to be obtained in the step (b).

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