JP3480183B2 - Reaming excavation management construction method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reaming excavation management and construction method, and more particularly to a management and construction method for reaming excavation in which a pilot hole is drilled after rock drilling and then the pilot hole is expanded.

[0002]

2. Description of the Related Art As one of the reaming excavation methods for expanding a pilot hole after drilling it, a vertical shaft of a mine rising from a horizontal shaft, a vertical shaft such as various headrace shafts, an inclined shaft or a horizontal shaft, especially in a rocky area. Raise boring applied when excavating a mine is known. This raise bowling
Generally, the procedure is as follows. That is, a drill unit is installed above a horizontal shaft, a pilot bit is attached to a drill rod, and a small-diameter pilot shaft is excavated toward the horizontal shaft. After excavating the pilot hole, the pilot bit is replaced with a reaming bit, and the reaming excavation is performed in which the pilot hole is expanded while pulling up the drill rod.

By the way, various cracks (fractures) having different formation timings and origins develop in the rock mass, and crush zones exist, and it is impossible to avoid these cracks and crush zones in rock excavation. . In particular, in the case of reaming excavation in which large-diameter holes are excavated in rock where the free surface is increased by excavating pilot holes, the presence of further cracks and fracture zones has various adverse effects on the excavation tools and the like. For example,
As will be described in detail later, an unbalanced load acts on the bit, which causes fatigue fracture due to repeated bending moments in the main stay of the bit, induces vibration and hole bending of the drill string, and causes collapse of the pilot hole wall.

[0004]

The present invention has been made based on the above technical background, and achieves the following objects.

An object of the present invention is to provide a reaming excavation management construction method capable of safely performing reaming excavation subsequent to pilot excavation without adversely affecting the excavation tools and the like.

[0006]

SUMMARY OF THE INVENTION The inventors of the present invention have
Focusing on drilling pilot holes prior to reaming,
Rotation speed, drilling torque,
By analyzing various excavation data such as bit load,
We came to remember that it is possible to accurately understand the properties of the bedrock that will be expanded around the pilot hole, that is, by reaming excavation. Further, it was further found that, under certain conditions, there is a close relationship between fluctuations in excavation torque and excavation rate, and cracks or fracture zones occurring in rock.

That is, regarding the rock conditions to be excavated, from the existing information such as the geological map, (1) the type of rock is constant. (2) The rock is relatively homogeneous and has no significant change in strength. Regarding the excavation conditions for pilot excavation, (1) rotation speed, bit load, and excavation fluid flow rate are kept constant from the characteristics of rotary excavation using a roller bit. (2) Regarding the properties of the rock to be excavated, consider a simple model as much as possible in order to clarify the relationship with the excavation data, and assume that the rock at the excavation site has no or very few cracks, and compressive fracture strength and pressure. It is assumed that the fracture strength does not change much.

Under these conditions, Table 1 shows the relationship between changes in the excavation data during pilot excavation and the rock mass condition.

[0009]

[Table 1]

From Table 1, the following can be considered. a) If the bedrock is uniform and stable, there will be no significant change in the excavation data unless the bit is worn or damaged. b) If the rock enters a portion where a crack is developed, the rotation of the bit becomes irregular and the excavation speed changes. That is, generally, the torque indicated by the excavation data largely fluctuates, and the excavation speed tends to increase. c) There are no factors other than cracks that can cause excavation torque fluctuations.

From the above consideration, if the excavation conditions are constant, there is a close relationship between the excavation torque fluctuation (amplitude) and the excavation rate and the rock mass crack, and the development of the rock mass crack causes the excavation torque fluctuation. Can be regarded as

[0012] This means that the more the cracks develop in the rock, the more the free surface of the rock increases, and the chipping action of the cutting edge of the bit and the large crushing force cause large crushing. It is thought to be due to hindering smooth rotation.

In this case, the cuttings are promptly removed if the hole bottom cleaning ability of the drilling fluid has a surplus.
The excavation is promoted more than when there is no crack, and the excavation rate increases. On the contrary, if the drilling fluid does not have sufficient cleaning ability, recutting by the bit occurs, the rate of excavation sharply decreases, the bit is consumed more, and the drilling torque abnormally increases.

In any case, the developed portion of the rock crack is
It is possible to select by the phenomenon of fluctuation of excavation torque and fluctuation of excavation rate. Therefore, if the development position of the rock crack can be detected in advance by the pilot excavation, it is possible to prevent the trouble from occurring by limiting the bit load, the rotation speed, and the like during the reaming excavation accordingly. Note that, as shown in Table 1, if a crack develops in the rock mass, uneven rotation may occur in response to fluctuations in the excavation torque, the rotation speed may slightly decrease, and the excavation fluid pressure may increase. However, noise such as pulsation of the piston pump is large, and it is difficult to select these changes remarkably as the development of rock cracks.

The present invention was made on the basis of the above-mentioned viewpoints and findings, and employs the following means.

That is, according to the present invention, in a method of performing reaming excavation for expanding the pilot hole after excavating the pilot hole, a step of collecting excavation data when the pilot hole is excavated, and the pilot hole from the excavation data. A reaming excavation construction management method comprising: a step of evaluating a rock property around the rock and a step of setting an excavation condition at the time of reaming based on the rock property.

The present invention also relates to a reaming excavation construction management method characterized in that the rock property is evaluated from the torque fluctuation during excavation of the pilot hole and the excavation rate.

Further, the present invention is the reaming excavation construction management method, wherein the excavation rate includes the excavation rate per unit load.

Further, the present invention is the reaming excavation construction management method, wherein the excavation rate includes the excavation rate per unit rotational speed.

Further, the present invention is characterized by comprising a step of collecting excavation data at the time of the reaming excavation and a step of evaluating the properties of the entire rock mass from the excavation data of the pilot and the reaming excavation. Reaming excavation construction management method.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the embodiment of the present invention, a raise drill is used for reaming drilling, and FIG. 1 is a front view showing the drill unit. A drill unit 1 of a raise drill includes a drill head 2 which is guided and supported by a guide rod (not shown) so as to be able to move up and down. The drill head 2 is moved up and down by an operation of a thrust cylinder 5 having a piston rod 3 fixed to a base 4.

The drill head 1 is provided with a spindle 7 on which a drill rod 6 is mounted, and the spindle 7 rotates in the forward and reverse directions by the operation of a hydraulic motor 8. At the time of excavation, the drill rod 6 is given a pushing force or a pulling force by the travel cylinder 4, and a rotational force is given by the hydraulic motor 7.

FIG. 2 is a view for explaining the procedure of raise boring using a raise drill. The drill unit 1 has a space above the lower horizontal shaft 9, for example, an upper horizontal shaft 10.
Is installed in. The pilot bit 12 is attached to the tip of the drill rod 6 via the spiral stabilizer 11, and the pilot bit 12 is rotated while pushing the drill rod 6 into the bedrock to excavate the pilot hole toward the lower horizontal shaft 9 ((a)). ).

When reaching the lower horizontal shaft 9, the pilot bit 12 is replaced with a reaming bit 14 having a larger diameter ((b)), and the reaming bit 14 is rotated while pulling out the drill rod 6 to expand the pilot hole. Reaming excavation with a hole is performed ((c)).

FIG. 3 is a functional block diagram showing an apparatus for collecting excavation data. The drill unit 1 is provided with the following various sensors. Pressure detector 2
Reference numerals 1 and 22 are for detecting the thrust pressure of the travel cylinder 5. One pressure detector 21 is forward (pushing) pressure, and the other pressure detector 22 is backward (pulling out) pressure.
Detect each pressure.

The displacement detector 23 is for detecting the displacement of the drill head 2, the rotary encoder 24 is for detecting the rotational speed (bit rotational speed) of the drill rod 6, and the electromagnetic flow meter 25 is for excavating. The pressure detector 26 is for detecting the fluid flow rate, and the pressure detector 26 is for detecting the drilling fluid pressure. Further, the pressure detectors 27 and 28 provided in the power unit 30 are for detecting the hydraulic oil pressure of the hydraulic motor 8. One pressure detector 27 is a forward rotation pressure and the other pressure detector 28 is a reverse rotation pressure. Detect each pressure.

The detection signals of the sensors 21 to 28 are output to the arithmetic processing unit 3 including a programmable controller or the like.
Input to 1. That is, the detection signal is the pressure transducer 3
2, converted into an electric signal through the displacement converter 33 or the frequency-voltage converter 34, digitized by the A / D converter 35, and input to the CPU 36. The CPU 36 performs arithmetic processing based on the detection signal to calculate excavation data. Excavation data includes the following. a) Time b) Rotational speed (bit rotation speed) c) Excavation torque ... Calculated from hydraulic oil pressure of hydraulic motor 8 and motor performance curve d) Bit load ... Calculated from thrust pressure of travel cylinder 5 and cylinder cross-sectional area e) Excavation depth ... Calculated from displacement of drill head 2 and number of drill rods used f) Excavation speed ... Calculated from displacement of drill head 2 and time g) Excavation fluid pressure f) Extrusion fluid flow rate , And is read by the memory card read / writer 38 and written in the non-contact type memory card 39.

The reaming excavation management construction method according to the present invention including the excavation data collection as described above is carried out as follows. FIG. 4 is a flowchart of pilot excavation. The construction of the pilot excavation itself is performed by the procedure as described in FIG. 2, and the excavation data is collected by the device shown in FIG. 3 at the time of excavating the pilot hole (step S
1). After completion of the pilot excavation, the excavation data is analyzed (step S2). The sampling of the excavation data is performed every 1 cm of the excavation depth as the minimum unit, the values for the excavation depth corresponding to about 1/3 of the excavation hole diameter are averaged, and the data for each 1 m of the excavation depth is used for the analysis.

FIG. 5 is a block diagram of equipment for analyzing excavation data. The excavation data recorded in the memory card 39 is read by the memory card reader 40, transmitted to a personal computer 41 as an analysis means, and analyzed.

Here, as preconditions for associating the torque fluctuation and excavation rate during excavation with the development of rock cracks,
The conditions for excavation, that is, the rotation speed, the bit load, and the excavation fluid are constant, as described above. However, in actual pilot excavation, if the excavation torque fluctuates significantly, in order to prevent adverse effects on the excavation, the bit load should be reduced to control the excavation speed and operate to stabilize the rotation of the bit. There is. in this case,
Both the bit load and the rotation speed, which are changed by the control of the excavator, directly affect the excavation rate.

Therefore, in the analysis, the following method is adopted. That is, in order to correct the changes in bit load and rotation speed, the digging rate per unit bit load (hereinafter, load digging rate) and the digging rate per unit rotation (hereinafter, rotary digging rate) are used for the digging rate. To do. The load excavation rate and the rotary excavation rate can be expressed by the following equations. PW = DL / t / W PN = DL / t / N Where, PW: load excavation rate, PN: rotational excavation rate, DL: excavation length, t: excavation time W: bit load, N: bit rotation speed is there.

The use of two data, the load excavation rate and the rotary excavation rate, as the excavation rate is as follows. The bit load data used to calculate the load excavation rate is calculated from the thrust pressure of the travel cylinder as described above, but the vibration of the drill bit in the direction of the rotation axis causes the load cylinder to vibrate through the drill pipe through load vibration. Is occurring.
As a result, the bit load data constantly changes, and the calculated load excavation rate often shows a value different from the actual value. On the other hand, since the bit rotation speed is less affected by the vibration of the excavation bit in the rotation axis direction, the calculated rotation excavation rate shows a value that is close to the actual value.

As described above, in rock excavation such as reaming excavation, since the influence of the bit load on the excavation speed is larger than that of the bit rotation speed, data of both the load excavation rate and the rotary excavation rate are obtained. Accurate bedrock information can be obtained by using it. That is, in the analysis, when the variation of the load excavation rate and the variation of the rotary excavation rate show the same tendency, it is considered as a true value, and when not, it is considered as false.

Excavation depth, excavation torque and excavation rate obtained as a result of data analysis (including load excavation rate and rotary excavation rate)
Is output to the display unit of the personal computer 41 or the printer 42, and further recorded on a recording medium such as the floppy disk 43.

FIG. 6 exemplifies a chart showing changes in the excavation torque and the excavation rate with respect to the excavation depth. Based on this, the rock mass properties are evaluated for each excavation depth (step S3).
At the time of evaluation, in order to assume a rock crack condition, the fluctuation width (amplitude) of the excavation torque is compared with the excavation rate, and the change in the excavation torque amplitude and the excavation rate are synchronized. Judgment is made according to such judgment criteria. (1) When the excavation torque amplitude is small, the rock crack is inferior. (2) When the amplitude of excavation torque is large, the rock crack is predominant. (3) When the excavation torque has a large amplitude for a certain length of time, it is a fracture zone. Table 2 shows the rock mass property evaluation results regarding the data exemplified in FIG. 6 and possible troubles during reaming excavation.

[0036]

[Table 2]

FIG. 7 is a flowchart of reaming excavation subsequent to pilot excavation. The construction of reaming excavation itself is performed by the procedure as described in FIG. Preparations are made for reaming excavation (step S4), and reaming excavation conditions are set for each depth based on the rock mass property evaluation performed in step 3 of FIG. 4 (step S5). That is,
The maximum value of the bit rotation speed, the maximum value of the excavation torque, and the maximum value of the bit load that are allowed for each excavation depth are set. Corresponding to the rock mass property evaluation with respect to the data illustrated in FIG.
Reaming excavation conditions are shown in Table 2.

Reaming excavation is started and excavation data is collected in the same manner as in the case of pilot excavation (step S
6). During the reaming excavation, it is monitored whether or not the excavation data is within the normal range (step S7), and if not within the normal range, step 5 is executed again to reexamine the excavation conditions.
If the excavation data is within the normal range, excavation is continued.

During excavation Furthermore, it is determined whether or not the setting change depth of the reaming excavation condition has been reached (step S8),
If it has reached, step 5 is executed again to change the setting of the excavation condition. If the set change depth is not reached, excavation continues. Then, it is further determined whether or not the reaming end depth has been reached (step S9), and if not reached, the process returns to step 6. If the reaming end depth has been reached, the reaming is terminated (step S10), the excavation data collected by the reaming excavation and the pilot excavation data already collected are analyzed, and the properties of the entire rock mass are predicted.

Although the present invention has been described in the above embodiment by taking the case of reaming excavation using a raise drill as an example, the present invention is applicable not only to a raise drill but also to other excavators. Further, it is needless to say that the device for collecting the excavation data and the unit of sampling are merely examples, and the device configuration and timing different from those of the above-described embodiment can be adopted.

[0041]

As described above, according to the present invention, the reaming excavation subsequent to the pilot excavation can be safely carried out without adversely affecting the excavation tools and the like.

[Brief description of drawings]

FIG. 1 is a front view showing a drill unit of a raise drill used for reaming excavation.

FIG. 2 is a diagram illustrating a procedure of reaming excavation using a raise drill.

FIG. 3 is a functional block diagram showing an apparatus for collecting excavation data.

FIG. 4 is a flow chart of pilot excavation under the control construction method according to the present invention.

FIG. 5 is a device configuration diagram for excavation data analysis.

FIG. 6 is a diagram illustrating the relationship between the excavation torque and the excavation rate with respect to the excavation depth.

FIG. 7 is a flow chart of reaming excavation under the control construction method according to the present invention.

[Explanation of symbols]

1 ... Raise drill unit 2 ... drill head 5 ... Travel cylinder 6 ... drill rod 7 ... Spindle 8 ... Hydraulic motor 12, 13 ... Pilot bit 14 ... Reaming Bit 30 ... Power unit 31 ... Arithmetic processing unit 38 ... Memory card read / write 39 ... Memory card 40 ... Memory card read 41 ... Personal computer

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masao Akiyama 1-29-15 Chuo, Nakano-ku, Tokyo Minken Kogyo Co., Ltd. (72) Inventor Masa-Cho Aoyama 1-29-15 Chuo, Nakano-ku, Tokyo Within Mining & Industry Co., Ltd. (56) References Japanese Patent Publication No. 3-7796 (JP, B2) J. Sho 54-1441 (JP, Y2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) E21B 7/00-7/30 E21D 9/00 E21D 9/08

Claims (5)

(57) [Claims] 1. A method of performing reaming excavation for expanding the pilot hole after excavating the pilot hole, collecting excavation data at the time of excavating the pilot hole, and A reaming excavation management construction method comprising: a step of evaluating rock mass properties; and a step of setting excavation conditions at the time of reaming excavation based on the rock mass properties. 2. The reaming excavation method according to claim 1, wherein rock mass properties are evaluated based on a torque fluctuation during excavation of the pilot hole and an excavation rate. 3. The reaming excavation management construction method according to claim 2, wherein the excavation rate includes an excavation rate per unit load. 4. The reaming excavation management construction method according to claim 2, wherein the excavation rate includes an excavation rate per unit rotational speed. 5. The method according to claim 1, further comprising a step of collecting excavation data at the time of the reaming excavation, and a step of evaluating a property of the entire rock mass from the excavation data of the pilot and the reaming excavation. The reaming excavation management construction method according to 2, 3, or 4.