JP7393240B2 - Rock evaluation method using drilling energy - Google Patents

Description

The present invention relates to a method of evaluating the ground in front of a tunnel face using drilling energy measured by a drill jumbo during excavation of a mountain tunnel.

In the past, when excavating mountain tunnels, understanding the strength of the ground at the face in advance not only leads to more efficient blasting and the reduction of over-excavation, but also prevents sudden hollowing due to unexpected geological changes. This is important to prevent deformation and collapse of the face. Therefore, it has traditionally been possible to drill one or more (about 2 to 3) long holes with a drill and use the drilling data (drilling energy) to predict the properties of the ground in front of the face. (hereinafter referred to as drilling logging). Note that the length of the long drilled hole is approximately 20 to 40 m.

For example, in Patent Document 1 below, a hole is drilled with a hydraulic percussion drill, and the drilling depth obtained by drilling, the cumulative drilling time at each depth, instantaneous drilling speed, piston impact energy, feeding force, torque, and water supply pressure are described. A drilling data file of This method uses drilling data from a hydraulic drill, which is characterized by mapping, performing rock evaluation using fracture energy, performing image processing using a computer, grasping the distribution of fracture energy, and predicting the geology in front of the face. A method for evaluating the rock mass and predicting the geology in front of the face has been proposed.

However, it has been difficult to obtain a detailed and accurate understanding of the ground conditions in front of the face using drilling data for one to three holes per face. Therefore, in recent years, computer-controlled drill jumbo machines have been used to automatically acquire drilling data, including the drilling position during drilling, as well as drilling energy during blast drilling and rock bolt drilling, and process this drilling data.・A system has been developed to analyze and understand the nature of the ground in front of the face.

For example, in Patent Document 2 listed below, there is a task of acquiring image data near the face, a task of three-dimensionally acquiring drilling data of the ground around the face, and a task of creating a geological development image based on the image data. and creating a contour map of drilling energy based on the drilling data, the method for evaluating the ground around a tunnel, which evaluates the ground condition at the back of the tunnel and in front of the tunnel face using the geological development image and the contour map. is proposed.

In addition, in the following non-patent document 1, the construction data (drilling energy of blast holes and rock bolt holes) of a drill jumbo used for excavating mountain tunnels is used to quantitatively and A rock evaluation system capable of detailed three-dimensional evaluation has been disclosed (see FIG. 9).

Special Publication No. 11-174046 JP 2017-201074 Publication

Masayuki Yamashita and two others, “Development of a three-dimensional rock evaluation system (DRISS-3D) using drill jumbo drilling data,” Nishimatsu Construction Technical Report VOL.41, Internet <URL: https://www.nishimatsu. co.jp/solution/engineering.php＞

In Patent Document 2 and Non-Patent Document 1, numerical values of drilling energy measured by a drill jumbo are stored in a storage device, and based on these numerical values, a two-dimensional contour diagram of the face or a three-dimensional contour diagram of the entire bird's-eye view is created. A diagram is now created.

At this time, since the drilling energy measurement points exist discretely, the drilling energy at locations other than the measurement points is calculated using geostatistical methods (spatial data interpolation processing method) in order to draw the contour map. The contour diagram is drawn based on the estimation.

Specifically, the inverse distance weighted averaging method (IDW method) or the Kriging method is exclusively used as the spatial data interpolation processing method. The former method, the inverse distance weighted averaging method, calculates estimated values using a weighted average using the reciprocal of the distance as a weight, based on the rule that the closer the point is to the point to be estimated, the greater the influence on the averaging process, while the latter method, the Kriging method, Estimates a linear, unbiased spatial interpolation value at any point within the analysis area using the maximum likelihood method, least squares method, etc., based on the rule that the closer the distance, the higher the similarity. It is.

However, since the inverse distance weighted average method and the Kriging method perform spatial interpolation using data of the entire target face, there is a problem in that it is difficult to reproduce locations where the rock properties change. In other words, the numerical value for the estimated location uses the measured drilling energy value in the circumferential direction, but if there is a fracture zone or weak layer, the geology will be completely different inside and outside this boundary line. First, when predicting estimated values near this boundary line, data from strata beyond the boundary line is taken into consideration, which causes the problem that the boundary line, where the geology changes rapidly, becomes ambiguous and difficult to represent.

Therefore, the main problem of the present invention is to accurately identify the boundaries where the drilling energy changes rapidly when creating a two-dimensional contour diagram of the face or a three-dimensional contour diagram of the entire bird's-eye view using the drilling energy measured by the drill jumbo. The purpose of this paper is to propose a method for evaluating rock formations using drilling energy that can be expressed.

In order to solve the above problems, the present invention according to claim 1 is such that when a drill jumbo drills a charging hole in a face, the drilling location and the drilling energy are automatically measured, and based on this, the two-dimensional contour of the face is measured. When evaluating the ground in front of the face by creating a map or 3D contour map of the ground,
A first step of organizing the drilling energy of the drilling locations, extracting locations where the drilling energy suddenly changes, and determining the line as a boundary line of geological properties if there are consecutive locations of sudden changes;
a second step of dividing the area into areas divided by the boundary line;
The third step is to divide the target rock range into meshes of a predetermined shape, and estimate the estimated drilling energy of the mesh belonging to each area by a spatial data interpolation method based only on the measured drilling energy in that area. ,
A fourth step of creating a two-dimensional contour map of the face or a three-dimensional contour map of the rock based on the drilling energy values of each of the meshes is provided.

In the invention as claimed in claim 1, first, the drilling energies of the drilling locations are sorted out, and the locations where the drilling energy suddenly changes are extracted, and if the sudden changes are continuous, that line is determined to be the boundary line of the geological properties. (first step). If boundaries of geological properties are confirmed, then divide the areas into areas divided by the boundaries (second step), then divide the target geological range with a mesh of a predetermined shape, The drilling energy estimation value of each mesh belonging to each area is estimated by the spatial data interpolation processing method based only on the drilling energy measurement value within that area (third step). Then, a two-dimensional contour map of the face or a three-dimensional contour map of the ground is created based on the drilling energy value of each mesh (fourth step).

Conventionally, the drilling energy at an arbitrary point was estimated using a spatial data interpolation method using the drilling energy measurement value of the entire face, but in the present invention, first of all, there is a fault (boundary line) where the geological properties suddenly change. In this case, the area is divided into areas divided by this boundary line, and the estimated drilling energy value of each mesh belonging to each area is estimated using a spatial data interpolation processing method based only on the drilling energy measurement value within that area. By doing so, the drilling energy measurements in areas other than the area including the mesh are not used as reference data for the spatial data interpolation processing method. In other words, the geological properties of each area divided by the boundary line differ greatly, but in the past, estimates were made by also referring to the drilling energy measurements of the area beyond the boundary line. In the case of such a method, the numerical values at places with sudden geological changes were relaxed, making it difficult to express the boundaries of rapidly changing geology, but in the case of this method, basically the same or similar geological strata are set as one area. , estimated by a spatial data interpolation process based only on the drilling energy measurements within this area. Therefore, the numerical values of drilling energy will differ greatly between the areas near the inside and outside of the boundary line, making it possible to accurately represent boundaries where geological properties change rapidly.

As the present invention according to claim 2, a plurality of boreholes are logged in advance from the face to the ground in front to obtain a rough three-dimensional distribution of drilling energy, and the method according to claim 1 is used. A rock formation based on drilling energy, characterized in that when a two-dimensional contour map of a face or a three-dimensional contour map of a rock is obtained, the rough three-dimensional distribution of the drilling energy is overwritten and updated accordingly. An evaluation method is provided.

The invention as set forth in claim 2 provides that, when excavating a mountain tunnel, a plurality of boreholes are normally logged in advance from the face to the ground in front of the mountain to obtain a rough three-dimensional distribution of drilling energy. put. However, although this rough three-dimensional distribution of drilling energy contributes to rough geological predictions, it has not reached the point where it is possible to quantitatively and accurately evaluate the properties of the rock. Therefore, if a two-dimensional contour map of the face or a three-dimensional contour map of the ground is obtained by the method according to claim 1 using the drilling energy obtained by drilling the charge hole performed in each excavation cycle, the By overwriting and updating the rough three-dimensional distribution of the drilling energy, it becomes possible to predict the ground in front of the face with higher accuracy.

The present invention according to claim 3 is characterized in that the first to fourth steps described in claim 1 are applied to rock bolt drilling by a drill jumbo to obtain a three-dimensional contour diagram of drilling energy. A method for evaluating rock formations using drilling energy is provided.

The invention as set forth in claim 3 above obtains a three-dimensional contour diagram of drilling energy by applying the first to fourth steps as set forth in claim 1 to rock bolt drilling using a drill jumbo. It is.

As described in detail above, according to the present invention, when creating a two-dimensional contour diagram of a face or a three-dimensional contour diagram of the entire bird's-eye view using the drilling energy measured by a drill jumbo, boundaries where the drilling energy rapidly changes are detected. You will be able to express yourself clearly.

FIG. 2 is a side view of a tunnel showing the procedure for excavation using a drill jumbo. FIG. 3 is a perspective view of the working face showing the location of borehole logging. This is an example of a schematic three-dimensional distribution map of drilling energy obtained by drilling well logging. FIG. 3 is a front view of the face showing an example of a charging hole drilling pattern of the face. FIG. 3 is a front view of a face showing an example of area division when there is a location where drilling energy suddenly changes. It is a front view of a face in which the ground is divided into meshes. It is a face contour diagram of drilling energy. FIG. 3 is a diagram illustrating how to overwrite and update a schematic three-dimensional distribution map. It is a three-dimensional display diagram of the drilling energy of the rock evaluation system according to Non-Patent Document 1.

Embodiments of the present invention will be described in detail below with reference to the drawings.

As shown in Figure 1, when excavating a mountain tunnel, heavy equipment for tunnel construction, such as a drill jumbo 5, a sprayer 6, and a wheel loader, is placed near the face.For example, the upper and lower halves are excavated simultaneously. Using the mini-bench construction method, the upper and lower halves are drilled for rock bolts and charged holes and charged at the same time, and then the upper and lower halves are cut down at once. Excavation is carried out in each cycle, following the steps of installation, erection of steel shoring, secondary spraying, and driving of rock bolts. In addition, a center will be placed behind the face, and construction of the lining and invert construction will be carried out.

[Drilling logging]
When excavating, it is important to predict the existence of fault fracture zones and local weak areas in advance and take countermeasures. For this purpose, in order to roughly predict the nature of the ground in front of the face, we performed drilling logging over a length range of approximately 30 to 50 m using the Drill Jumbo 5 rock drill, and The drilling energy is continuously measured along the The number of locations for drilling and logging is generally one or more. For example, as shown in FIG. 2, borehole logging is performed at three locations on both sides of the tunnel face and at the top using long holes 10, 10, . . . .

In recent years, many computer-controlled drill jumbo machines have become popular, making it possible to automatically obtain drilling data such as the drilling position, drilling energy, and angle data of the drilling direction during drilling. These excavation data are wirelessly communicated to the communication base station 2, then transmitted to the management computer 1 in the field office H via the communication cable 3 or wirelessly, and stored in the storage device. Of course, it is also possible to transmit the excavation data not only to the field office but also to the management computer 8 installed at the head office or the like by remote communication means such as the Internet or a dedicated line via the modems 7, 7.

The above-mentioned drilling energy indicates the amount of energy required to drill into the rock per unit volume, and the harder the rock, the more drilling energy is required, so this is used as an index to understand the properties of the rock. becomes possible. This drilling energy is determined by the following formula (1).

ここに、Ｅｄ：穿孔エネルギー(J/cm³)
Ｅｐ：打撃エネルギー(J)＜下式(2)による＞
Ｃｐ：打撃数(bpm)
Ｋ ：損失係数
Ｖｄ：穿孔速度(cm/min)
Ｓ ：孔断面積(cm²)

Here, Ed: drilling energy (J/cm ³ )
Ep: Impact energy (J) <according to formula (2) below>
Cp: Number of blows (bpm)
K: Loss coefficient Vd: Drilling speed (cm/min)
S: Hole cross-sectional area (cm ² )

ここに、Ｅｐ：打撃エネルギー(J)
Ａ ：ピストン受圧面積(cm²)
Ｌ ：ピストンストローク(m)
Ｐｐ：打撃圧(kgf/cm²)
削孔検層によって得た３箇所の穿孔エネルギーを用い、空間データ補間処理法によってそれらの中間領域の穿孔エネルギーを推測することにより穿孔エネルギーの概略的３次元分布を得るようにする。図３はその概略的３次元分布図の例を示したものである。

Here, Ep: Strike energy (J)
A: Piston pressure receiving area (cm ² )
L: Piston stroke (m)
Pp: Impact pressure (kgf/cm ² )
A rough three-dimensional distribution of drilling energy is obtained by estimating the drilling energy in the intermediate region using the drilling energy at three locations obtained through drilling logging and using a spatial data interpolation processing method. FIG. 3 shows an example of a schematic three-dimensional distribution diagram.

[Drilling energy measurement when drilling a charging hole]
In the excavation work for each cycle, first, the drill jumbo 5 drills a charging hole 11 in the face.

Generally, the formation of the charging hole 11 is performed by first forming a free surface by core blasting, and then by blowing the free surface formed by core core removal and sequentially expanding the circumference in a blasting pattern. The drilling is done by When drilling the charging hole 11, drilling data including the drilling position and drilling energy are automatically measured by computer control. Then, based on this drilling energy measurement value, a two-dimensional contour map of the face or a three-dimensional contour map of the ground is created to evaluate the ground in front of the face. The details will be explained below based on the drawings.

<First step>
Organize all the drilling energies of the drilling points formed on the face S, and extract the points where the drilling energy suddenly changes. If there are consecutive areas of rapid change, that line is determined to be a boundary line where the geological properties are rapidly changing. For example, in the drilling pattern diagram of the charging hole in the face shown in Figure 5, we compared the drilling energy at each drilling position and examined whether there were any places where the drilling energy suddenly changed. If a line can be assumed, that line is set as the boundary line 12 of the geological properties.

Note that although the illustrated example shows an example in which there is one boundary line 12, it is naturally assumed that there are two or more boundary lines. Although the boundary line 12 is shown as a straight line, it is naturally assumed that the boundary line may be bent in the middle, be a curved line, or be a curved line.

<Second step>
Next, as shown in FIG. 5, areas are divided into areas divided by boundary lines 12. For example, as shown in the figure, an area on the lower left side of the boundary line 12 is set as area A, and an area on the upper right side of the boundary line is set as area B.

Note that although the illustrated example shows an example in which the area is divided into two, it is naturally assumed that the area is divided into three or more.

<3rd step>
As shown in FIG. 6, the area of the ground where the borehole has been drilled is targeted, and in the illustrated example, the entire face is targeted, and is divided into meshes of a predetermined shape. In the illustrated example, division is basically performed using a square mesh. At this time, the mesh that overlaps the outer edge of the face is a triangular or polygonal mesh. Furthermore, it is desirable that the mesh intersecting the boundary line 12 be a triangular or polygonal mesh that includes the boundary line as one side. Then, in estimating the drilling energy value of each mesh belonging to each area A, B, estimation is performed by a spatial data interpolation processing method based only on the drilling energy measurement value in the corresponding area. As the spatial data interpolation processing method, it is desirable to use the aforementioned inverse distance weighted average method (IDW method) or the Kriging method.

In addition, if there is a drilling energy measurement value inside the mesh, that measurement value is used as the drilling energy value, and if there is no drilling energy measurement value inside the mesh, spatial data interpolation is performed based only on the neighboring drilling energy measurement values. If estimation is performed using a processing method, processing time can be shortened.

<Fourth step>
Once the drilling energy values have been set for all meshes, a two-dimensional contour map of the face (or a three-dimensional contour map of the ground) is created based on the drilling energy values of each mesh. For example, as shown in FIG. 7, a two-dimensional contour diagram of drilling energy values for the face S is created.

<Fifth step (additional step)>
After obtaining a highly accurate drilling energy contour diagram for the entire face surface based on the drilling results of the jumbo drill, as shown in Fig. 8(A)(B), The rough three-dimensional distribution of drilling energy obtained through well logging is sequentially overwritten and updated.

At this time, the data on the drilling energy contour diagram of the face is for the length of the drilling of the charging hole 11, but the data on the tunnel length is determined by the rough three-dimensional distribution of drilling energy obtained by drilling logging. Since the trend of drilling energy along the direction can be grasped, it is possible to predict the ground in front of the face in detail and accurately based on the drilling energy contour map of the face and the rough three-dimensional distribution of the drilling energy. Become.

[Other form examples]
(1) In the above embodiment, the boundary line 12 is defined as a single line, but it can also be defined as a strip-shaped line having an arbitrary width.
(2) In the above embodiment, the drilling energy was measured for the charging hole 11, but it is also possible to measure the drilling energy in the same way when drilling the rock bolt, and to show the results as a three-dimensional contour diagram.

1.8... Management computer, 2... Communication base station, 3... Communication cable, 5... Drill jumbo, 6... Spraying machine, 7... Modem, 10... Long hole drilling, 11... Charge hole, 12... Boundary line , S... face

Claims (3)

When a drill jumbo drills a charging hole in a face, it automatically measures the drilling location and the drilling energy, and based on this, creates a two-dimensional contour map of the face or a three-dimensional contour map of the ground, and maps the area in front of the face. When evaluating the ground,
A first step of organizing the drilling energy of the drilling locations, extracting locations where the drilling energy suddenly changes, and determining the line as a boundary line of geological properties if there are consecutive locations of sudden changes;
a second step of dividing the area into areas divided by the boundary line;
The third step is to divide the target rock range into meshes of a predetermined shape, and estimate the estimated drilling energy of the mesh belonging to each area by a spatial data interpolation method based only on the measured drilling energy in that area. ,
A method for evaluating rock formations using drilling energy, comprising a fourth step of creating a two-dimensional contour map of the face or a three-dimensional contour map of the rock based on the drilling energy values of each of the meshes. In advance, a plurality of drilling logs are performed from the face to the ground in front to obtain a rough three-dimensional distribution of drilling energy, and a two-dimensional contour map of the face or the ground is obtained by the method according to claim 1. 1. A method for evaluating rock formations using drilling energy, characterized in that, once a three-dimensional contour map is obtained, the rough three-dimensional distribution of drilling energy is overwritten and updated accordingly. A rock formation evaluation method based on drilling energy, characterized in that the first to fourth steps according to claim 1 are applied to rock bolt drilling using a drill jumbo to obtain a three-dimensional contour diagram of drilling energy.

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