JP2017025637A - Tunnel excavation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To propose a tunnel excavation method capable of efficient excavation.SOLUTION: There is provided a tunnel excavation method for excavating the natural ground by repeating a swing cycle several times for cutting the natural ground by moving a cutter wheel 3 while rotating it. In the tunnel excavation method, a penetration amount of a cutter 31 and a moving speed of the cutter wheel 3 in the swing cycle of this time are set on the basis of the penetration amount of the cutter 31, the moving speed of the cutter wheel 3 and a current value of a cutter motor with respect to the natural ground in the swing cycle of the last time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tunnel excavation method using a tunnel excavator.

A tunnel excavator (free-section excavator) used for a mechanical excavation method includes an excavator body, a boom rotatably provided on the excavation body, and a cutter wheel (cutter head, cutter drum, etc.) supported by the boom. Are generally provided (see, for example, Patent Document 1).
In tunnel construction using a tunnel excavator, excavation of natural ground is performed by moving the boom holding the cutter wheel up and down and left and right while rotating the cutter wheel in a certain direction. At this time, the cutter (disc cutter, pick, etc.) provided on the cutter wheel is penetrated into the rock using the expansion / contraction function of the boom or the thrust function of the excavator body.

Japanese Patent No. 3362794

Conventionally, the amount of penetration of the cutter into the rock mass and the moving speed of the cutter wheel are generally set by the experience and sense of the operator.
However, since the natural ground changes from time to time, if the amount of penetration of the cutter does not follow the change of the natural mountain, the amount of penetration may be excessive or excessive.
When the amount of penetration of the cutter is excessive, a load exceeding the rating acts on the cutter motor, so that the cutter motor stops or the tunnel excavator is damaged.
In addition, when the amount of penetration of the cutter is too small, the excavation cycle time is extended due to useless movement such as the cutter wheel swinging idle.

Further, if the moving speed of the cutter wheel is too fast, an unexcavated portion may be generated. Conversely, if the moving speed of the cutter wheel is too slow, the excavation cycle time is affected.
Further, the moving speed of the cutter wheel is generally set to a constant speed regardless of the load acting on the cutter wheel. Therefore, the travel time in the excavated part becomes a loss time.

  From such a viewpoint, an object of the present invention is to propose a tunnel excavation method using a tunnel excavator that enables efficient excavation.

  In order to solve the above-mentioned problem, the present invention is a tunnel excavation method for excavating a natural ground by repeating a swing cycle in which the cutter wheel is rotated while moving to cut the natural ground a plurality of times. Based on the amount of cutter intrusion to the ground in the swing cycle, the moving speed of the cutter wheel, and the current value of the cutter motor, the amount of cutter penetration and the moving speed of the cutter wheel in the current swing cycle are set.

  The cutter penetration amount and the cutter wheel moving speed are set by, for example, a first threshold value in which the current value is lower than the rated current upper limit value of the cutter motor (for example, 80% of the rated current upper limit value of the cutter motor). If it is less than this, at least one of the amount of penetration of the cutter and the moving speed of the cutter wheel in the current swing cycle is made larger than that in the previous swing cycle. Further, when the current value is equal to or higher than a second threshold value (for example, 95% of the rated current upper limit value of the cutter motor) higher than the first threshold value, the amount of cutter penetration and the cutter in the current swing cycle At least one of the moving speeds of the wheels is made smaller than the previous swing cycle.

  According to such a tunnel excavation method, since the penetration amount of the cutter and the moving speed of the cutter wheel are set based on the result of the previous swing cycle, the natural ground can be cut with the optimum current value of the motor. Therefore, efficient excavation is possible.

Further, if the moving speed of the cutter wheel is changed in accordance with the current value of the cutter motor during excavation, excavation corresponding to changes in natural ground becomes possible, which is efficient.
Furthermore, when the current value of the cutter motor during excavation is equal to or less than a third threshold value set lower than the first threshold value (for example, 20% of the rated current upper limit value of the cutter motor), the tunnel excavator If the cutter wheel is moved at the maximum mechanical capacity speed, the moving time of the cutter wheel can be shortened, and consequently the cycle time of the swing cycle can be shortened.

  According to the tunnel excavation method using the tunnel excavator of the present invention, efficient tunnel excavation is possible.

It is a figure which shows the tunnel excavator which concerns on embodiment of this invention, Comprising: (a) is a top view, (b) is a side view, (c) is an A arrow view of (a). (A) And (b) is a schematic diagram which shows a swing cycle. It is a graph which shows the relationship between the penetration amount of a cutter, and the electric current value of a cutter motor.

In the present embodiment, a tunnel excavation method using the tunnel excavator 1 will be described.
The tunnel excavator 1 of the present embodiment is a so-called free section excavator, and includes an excavator body 2, a cutter wheel 3, and a boom 4, as shown in FIG.

As shown in FIG. 1B, the excavator main body 2 is provided with a crawler 21, a boom support portion 22, a thrust jack 23, and a gripper 24.
The crawler 21 is a traveling unit of the tunnel excavator 1. In this embodiment, the crawler type tunnel excavator 1 is adopted, but the traveling means of the tunnel excavator 1 is not limited and may be, for example, a tire type (wheel type). Moreover, the tunnel excavator 1 may run on a rail laid in the tunnel.

  The crawler 21 is driven by a hydraulic motor (not shown) mounted on the excavator body 2, and the hydraulic motor is driven by the hydraulic pressure of a hydraulic pump (not shown) mounted for excavation. The hydraulic pump is driven by an electric motor (not shown), and the electric motor is driven by electric power transmitted via a cable from a generator or a commercial power source disposed on the wellhead side. A cable handler 25 for moving the cable is provided at the rear part of the excavator body 2.

The boom support portion 22 includes a protruding portion 221 that protrudes from the front end of the excavator main body 2, and the boom 4 is rotatably supported by the protruding portion.
The boom support portion 22 is slidably supported by the excavator body 2, and moves along the traveling direction of the tunnel excavator 1 when the thrust jack 23 is expanded and contracted.

The thrust jack 23 is interposed between the boom support portion 22 and the excavator body 2 as shown in FIGS. 1 (a) and 1 (b).
In the present embodiment, four thrust jacks 23 are provided, but the number and arrangement of the thrust jacks 23 are not limited.
Although the thrust amount (stroke length) of the thrust jack 23 of this embodiment is 1.2 m, the thrust amount of the thrust jack 23 is not limited. For example, you may set suitably in the range of 0.7m-1.2m.

As shown in FIG. 1C, the excavator body 2 is fixed by the gripper 24 coming into contact with the inner wall of the tunnel.
In the present embodiment, grippers 24 are provided on the front, rear, left and right of the excavator body 2 (see FIGS. 1A and 1B). The gripper 24 is attached to the excavator main body 2 via an extendable support member 26. As the support member 26 extends, the gripper 24 comes into contact with the inner wall of the tunnel.
The support member 26 is attached to the excavator body 2 so as to be rotatable in a direction intersecting the moving direction of the tunnel excavator 1.
In the present embodiment, four grippers 24 are provided, but the number and arrangement of the grippers 24 are not limited.

As shown in FIGS. 1A and 1B, the cutter wheel 3 is a member that cuts natural ground, and is disposed in front of the excavator body 2.
The cutter wheel 3 has a circular shape in a side view and is rotatably held at the tip of the boom 4. The cutter wheel 3 of the present embodiment has a diameter of 2.7 m, but the dimensions of the cutter wheel 3 are not limited.

  A plurality of cutters 31, 31,... Are attached to the peripheral surface of the cutter wheel 3. In the present embodiment, a disk cutter is employed as the cutter 31, but the configuration of the cutter 31 is not limited. The cutter wheel 3 may be a drum type, and the shape of the cutter wheel 3 is not limited.

In the present embodiment, a plurality of cutters 31, 31,... Are arranged in three rows on the peripheral surface of the cutter wheel 3. .. Are arranged at equal intervals in the central row, and four cutters 31, 31,... Are arranged at equal intervals in the left and right rows. Moreover, the cutters 31 in the left and right rows are inclined in a direction that spreads left and right.
The number, arrangement, and orientation of the cutters 31 are not limited and may be set as appropriate.

The boom 4 is attached to the boom support portion 22.
The boom 4 of the present embodiment includes a swing boom 41 and a pitching boom 42.
The swing boom 41 can turn horizontally in a plane parallel to the bottom plate.

  In the present embodiment, swing cylinders 43 are provided on the left and right of the swing boom 41. The swing cylinder 43 has one end attached to the swing boom 41 and the other end attached to the boom support portion 22. As one swing cylinder 43 expands and the other swing cylinder 43 contracts, the swing boom 41 rotates left and right.

The pitching boom 42 can rotate in the vertical direction around the tip of the swing boom 41. The cutter wheel 3 is rotatably supported at the tip of the pitching boom 42.
In the present embodiment, a pitching cylinder 44 is disposed along the upper surface of the pitching boom 42. One end of the pitching cylinder 44 is attached to the pitching boom 42, and the other end is attached to the swing boom 41. The pitching boom 42 rotates in the vertical direction when the pitching cylinder 44 expands and contracts.

Next, a tunnel excavation method using the tunnel excavator 1 will be described.
In the tunnel excavation method, a natural ground is excavated by repeating a swing cycle in which the cutter wheel 3 is moved while being rotated to cut the natural ground a plurality of times.
In the present embodiment, as shown in FIG. 2 (a) and (b), the working face K right (working face right) is divided into a K _R and the left side (working face left) K _L drilling alternately. That is, after the cutting face right K _R to a predetermined extension (e.g., 1m) excavating the tunnel boring machine 1, by moving the tunnel boring machine 1 performs the cutting of the cutting face left K _L. Incidentally, the cutting of the working face K may be performed from the working face left K _L. Further, the number of divisions at the time of cutting the face may be set as appropriate according to the shape of the tunnel cross section. May be.

When cutting the working face right K _R, by repeatedly performing the swing cycle, a predetermined extension (e.g., 1m) cutting. Hereinafter, an example of a swing cycle is shown. In the swing cycle shown below, the cutting start position is set at the center of the tunnel, but the cutting start position may be set at the left and right ends of the tunnel.
In each swing cycle, first, the cutter wheel 3 is disposed below the center of the face K (cutting start position), and the thrust jack 23 is extended while rotating the cutter wheel 3. By doing so, the cutter 31 penetrates the bedrock.

The amount of penetration of the cutter 31 into the rock and the moving speed of the cutter wheel 3 are set based on the amount of penetration of the cutter 31 with respect to the natural ground in the previous swing cycle, the moving speed of the cutter wheel 3, and the current value of the cutter motor. .
In this embodiment, when the current value of the cutter motor in the previous swing cycle is less than 80% (first threshold value) of the rated current upper limit value of the cutter motor, the amount of penetration of the cutter 31 in the current swing cycle And at least one of the moving speeds of the cutter wheel 3 is made larger than the previous swing cycle. On the other hand, if the current value of the cutter motor in the previous swing cycle is 95% or more of the upper limit value of the rated current of the cutter motor (second threshold), the amount of cutter penetration and the cutter wheel in the current swing cycle At least one of the moving speeds is made smaller than the previous swing cycle.
The setting method (reference) of the amount of penetration of the cutter 31 into the rock and the moving speed of the cutter wheel 3 is not limited. For example, the penetration amount of the cutter 31 may be calculated based on the relationship between the current value of the cutter motor and the rated current upper limit value of the cutter motor in the swing cycle.

Next, as shown in FIG. 2A, with the cutter 31 penetrating into the bedrock, the boom 4 is turned to the right toward the right end of the face K, and the face K is cut in the lateral direction ( Arrow S1).
When the cutter wheel 3 reaches the right end of the face K, the boom 4 is turned to the left and turned upward toward the center of the face K (arrow S2).
When the cutter wheel 3 reaches the center of the face K, the boom 4 is raised toward the top of the tunnel (arrow S3).
When the cutter wheel 3 reaches the top of the tunnel, the boom 4 is turned rightward and turned downward toward the right end of the face K (arrow S4).

The current value of the cutter motor during cutting is transmitted to the control device as needed and stored in the storage unit of the control device. The control device compares the current value of the cutter motor during cutting with the rated current upper limit value of the cutter motor, and changes the moving speed of the cutter wheel 3 according to the current value. Note that the current value of the cutter motor during cutting is desirably set in the vicinity of the upper limit of the rated current of the cutter motor.
That is, when the current value of the cutter motor is large (for example, when it is 95% or more of the rated current upper limit value of the cutter motor), the cutter wheel is moved slowly to perform cutting reliably, and the current value of the cutter motor Is small (for example, when it is less than 80% of the rated current upper limit value of the cutter motor), the moving speed of the cutter wheel 3 is increased to shorten the swing time.
Furthermore, when the current value of the cutter motor during excavation is equal to or less than a threshold value (in this embodiment, 20% of the upper limit value of the rated current of the cutter motor (third threshold value)) (when the load is not applied to the cutter motor) The cutter 31 is moved at the maximum mechanical capacity of the tunnel excavator 1. In the present embodiment, the third threshold value is set to 20% or less of the rated current upper limit value of the cutter motor. However, the third threshold value is not limited to this, and the rated current upper limit value of the cutter motor is 30%. What is necessary is just to set suitably so that it may become% or less.

When the cutter wheel 3 reaches the right end of the face K, the boom 4 is turned leftward (arrow S5) toward the lower side of the center of the face K (cutting start position).
At this time, since the cutter wheel 3 is in a so-called idling state, the cutter wheel 3 is moved at the maximum mechanical capacity speed.

While stretching the thrust jack 23 in the working face right K _R, Once the swing cycle performed plural times completed drilling of a predetermined extension, to move the tunnel boring machine 1 on the left side of the tunnel, perform cutting working face left K _L.
When cutting the working face left K _L, as well as the cutting of the cutting face right K _R, repeated swing cycle. Swing cycles Face left K _L, first, in a state where we arranged cutter wheel 3 to the central lower side (cutting start position) of the working face K, to extend the thrust jack 23 while rotating the cutter wheel 3. By doing so, the cutter 31 penetrates the bedrock.

Next, as shown in FIG. 2 (b), with the cutter 31 penetrating into the bedrock, the boom 4 is turned toward the left end of the face K to cut the face K laterally (arrow S6). ).
When the cutter wheel 3 reaches the left end of the face K, the boom 4 is turned rightward and turned upward toward the center of the face K (arrow S7).
When the cutter wheel 3 reaches the center of the face K, the boom 4 is raised upward toward the top of the tunnel (arrow S8).
When the cutter wheel 3 reaches the top of the tunnel, the boom 4 is turned leftward and turned downward toward the left end of the face K (arrow S9).
Then, when the cutter wheel 3 reaches the left end of the face K, the boom is turned rightward (arrow S10) toward the lower side of the center of the face K (cutting start position).

According to the tunnel excavation method of the present embodiment, the cutter penetration amount and the cutter wheel moving speed are set based on the result of the previous swing cycle, so that the optimum current value of the cutter motor according to the ground condition is set. Can be cut. Therefore, efficient excavation is possible.
In other words, based on the data of the previous swing cycle, the ground is cut with the optimum amount of penetration according to the ground condition, so that overload on the cutter motor and damage to the mechanical structure are suppressed and useless movement The cycle time can be shortened by minimizing the above.

Further, since the moving speed of the cutter wheel 3 is changed in accordance with the current value of the cutter motor during excavation, excavation corresponding to changes in natural ground becomes possible, which is efficient.
Furthermore, when the cutting by the cutter wheel 3 is in a so-called idling state, the cutter wheel 3 is moved at the maximum speed of the tunnel excavator 1, so that the moving time of the cutter wheel 3 can be shortened. As a result, the cycle time of the swing cycle can be shortened.

Hereinafter, an example (Example) of a method for setting the amount of penetration of the cutter 31 into the rock and the moving speed of the cutter wheel 3 based on the current value of the cutter motor will be described. The rated current of the cutter motor is 141 (A).
In this example, the penetration amount of the cutter 31 is 6 mm (Example 1), 9 mm (Example 2), and 13 mm (Example 3) with respect to a standard rock, and the moving speed of the cutter wheel 3 is 14 m / The electric current value at the time of cutting by min was measured. FIG. 3 and Table 1 show the measurement results.

As shown in FIG. 3 and Table 1, the current values (average values) of the cutter motors in Examples 1 to 3 were 50.61 (A), 59.01 (A), and 71.68 (A), respectively. It was.
When the upper limit value of each example was calculated by Formula 1 based on the current value of each example, the upper limit values were 68.58 (A), 97.80 (A), and 141.96 (A), respectively. .
Upper limit value = average value + standard deviation × 2 Equation 1

Next, the ratio of the rated current to the actual value was calculated to be 2.06, 1.44 and 0.99, respectively.
Therefore, the corrected penetration amount may be a value obtained by multiplying the previous penetration amount by this ratio, and the corrected penetration amounts in Examples 1 to 3 may be 12.34 mm, 12.98 mm, and 12.91 mm, respectively. .

Although the embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.
For example, the tunnel to which the tunnel construction method of the tunnel excavator of the present embodiment can be applied may be a mechanical excavation type tunnel, and its scale and usage are not limited.
The method of determining the amount of cutter penetration and the cutter wheel movement speed at the current cutting using the current value of the cutter motor at the previous cutting is not limited to the methods (ratio and calculation method) described above. Absent.
Further, the speed of the cutter wheel at the time of cutting may be set at a preset speed, and does not necessarily have to be changed according to the current value of the cutter motor during excavation.

1 tunnel excavator 2 excavator body 3 cutter wheel 31 cutter 4 boom

Claims (4)

A tunnel excavation method for excavating natural ground by repeating a swing cycle of cutting the natural ground by moving the cutter wheel while rotating it,
Based on the amount of cutter penetration into the ground in the previous swing cycle, the cutter wheel movement speed, and the current value of the cutter motor, the cutter penetration amount and cutter wheel movement speed in the current swing cycle are set. How to tunnel. When the current value is less than a first threshold value lower than the upper limit value of the rated current of the cutter motor, at least one of the amount of cutter penetration and the cutter wheel moving speed in the current swing cycle is determined the previous time. Larger than the swing cycle,
When the current value is equal to or greater than a second threshold value that is higher than the first threshold value, at least one of the amount of cutter penetration and the cutter wheel movement speed in the current swing cycle is determined based on the previous swing cycle. The tunnel excavation method according to claim 1, wherein the tunnel excavation method is smaller.   The tunnel excavation method according to claim 1 or 2, wherein a moving speed of the cutter wheel is changed according to a current value of a cutter motor during excavation.   When the current value of the cutter motor during excavation is equal to or lower than a third threshold set lower than the first threshold, the cutter is moved at the maximum mechanical capacity of the tunnel excavator. The tunnel excavation method according to claim 2.

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