JPH11247597A - Excavation method of tunnel boring machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid inconveniences in excavation resulting from differences of strength of a natural ground and effectively excavate the ground continuously. SOLUTION: When a procedure starts, a natural ground is actually excavated. In this time, the revolution number R and the excavation speed V are adjusted and the ground is excavated so that a torque and a thrust force acting on a cutter head are kept lower than a limit value. Then, measured values of respective sensors are input and the strength σ of the natural ground being actually excavated is estimated and whether the strength σ is in between strengths σ1 and σ2 preset in advance or not is judged. If the strength σ is not in between σ1 and σ2, the ground is excavated in a synchronous excavation mode in which two sets of main grippers and thrust jacks are simultaneously stretched and contracted. When the strength σ is in between σ1 and σ2, the cutting head is advanced by making use of the reaction in the main gripper of one of sets. The other set of main gripper and thrust jack are contracted to prepare the excavating operation during the advancing process, and the ground is excavated in a continuous excavation mode repeating these motions alternately.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for excavating a tunnel boring machine (hereinafter abbreviated as a TBM machine), and more particularly to a method for excavating a tunnel boring machine (hereinafter abbreviated as a TBM machine), comprising two sets of independent thrust jacks and grippers. During the excavation, the other set of grippers and thrust jacks are contracted to prepare for excavation, and the excavation method of the TBM machine for excavating in the continuous excavation mode in which the excavation and the excavation preparation are alternately repeated is improved. It is about technology.

[0002]

2. Description of the Related Art A basic method of excavating a TBM machine is to take a reaction force against a wall of an excavation pit with a gripper and advance a cutter head which is rotationally driven by a thrust jack.

A double gripper-type TBM machine includes two independent sets of thrust jacks and grippers. While excavating with one set of grippers and thrust jacks, the other set of grippers and thrust jacks is used. Excavation is performed in a continuous digging mode in which the digging and the digging preparation are alternately repeated by contracting the digging preparation.

When the excavation is performed in the continuous excavation mode, the time required to change the gripper in the ordinary TBM machine can be eliminated, so that the operation rate of the TBM machine (excavation operation time with respect to the total operation time) is 10 to 30. It is expected to improve by about%.

[0005] However, such a method of excavating a double gripper type TBM machine has the following technical problems to be solved.

[0006]

That is, the TBM machine is divided into a front body, a first rear body, and a second rear body, and a gripper is provided on each body, and the front body and the first rear body are provided. There are a shield type in which a thrust jack is arranged between the trunk and the second rear trunk and a shield jack is provided in the second rear trunk, and an open type in which these trunks and the shield jack are not provided.

However, when continuously excavating with a shield type TBM machine, for example, if the ground to be excavated is collapsible or expansive, the collapsible earth and sand will bite into the slide points between the trunks, and As a result, the thrust required for excavation and the reduction force at the time of refilling cannot be secured by one set of thrust jacks.

Further, even in the open type, the frictional force of the cutter head and each support portion increases, and similarly, a situation in which thrust thrust and the like cannot be ensured by one set of thrust jacks.

Further, in the case of a cemented rock in which the excavation speed is reduced by the excavation ground, the superiority of the continuous excavation mode of the double gripper TBM machine which eliminates the refilling time is reduced due to a large increase in the excavation speed.

The present invention has been made in view of such a problem, and an object of the present invention is to select a digging mode according to the strength of a digging target ground to thereby increase the thrust for digging. It is an object of the present invention to provide a method of excavating a TBM machine that can ensure that the advantages of the continuous excavation mode can be used effectively.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention comprises two independent sets of thrust jacks and grippers. In the method of excavating a tunnel boring machine in a continuous excavation mode in which the other pair of grippers and thrust jacks are contracted to perform excavation preparation and the excavation and the excavation preparation are alternately repeated, in addition to the continuous excavation mode, A synchronous excavation mode for simultaneously driving the two sets of grippers and thrust jacks is provided, and one of the continuous excavation mode and the synchronous excavation mode is selected according to the strength of the ground to be excavated. According to the excavation method of the TBM machine configured as described above, for example, the excavation ground is a collapsible ground, an expansive ground,
The synchronous excavation mode can be selected in the case of a cemented rock mass, and the continuous excavation mode can be selected in the other masses.
When excavating in the collapsible ground and the expansive ground in the synchronized excavation mode, for example, even if the collapsed sediment is caught between the trunks, the required thrust and contraction force can be secured with a shield type TBM machine. it can. In addition, when the cemented rock mass is excavated in the synchronized excavation mode, a decrease in excavation speed can be reduced. Further, in the ground other than the collapsed ground, the expansive ground, and the hard rock ground, the excavation is performed in the continuous excavation mode, so that the superiority of this excavation method can be effectively used. In the present invention, the ground strength is determined by installing sensors for measuring a cutter torque, a thrust, a digging speed, and a cutter rotation speed in a tunnel boring machine, and excavating a unit volume based on a detection value of the sensors. Can be estimated based on the unit excavation energy consumed.
When this configuration is employed, the strength of the ground actually excavated by the TBM machine can be estimated with practical accuracy.
More specifically, the estimation of the ground strength is performed by determining the rotational torque obtained from the cutter torque sensor as T, the thrust thrust obtained from the thrust sensor as W, the digging speed obtained from the stroke sensor as V, The cutter rotation speed obtained from the rotation speed sensor is R, the excavation time is t,
Assuming that the excavation length is 1 and the face area of the tunnel boring machine is A, the total energy E consumed for excavating rock with the tunnel boring machine is as follows:
The unit excavation energy e is obtained by the following equation: e = E / (Al) = (Wl + 2πTRt) / (Al) = W / A + 2π (TRt) / (Al) = W / A + 2π (T / A) (R / V) Based on the unit excavation energy e obtained from this equation, the ground strength at the time of excavation by the tunnel boring machine can be estimated. Further, the present invention can be applied to any of a shield type or an open type TBM machine.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG.
1 shows a shield type double gripper TBM machine to which a method of excavating a TBM machine according to the present invention is applied.

The TBM machine shown in FIG.
The main body 10 includes a front body 11 and two independent first and second rear bodies 12 and 13.

At the front end of the front body 11, a cutter head 15 for excavating the ground is arranged. Also, the front torso 11
Is provided with a drive motor (hydraulic or electric drive, not shown) that rotationally drives the front gripper 16 and the cutter head 15 that extend and contract toward the excavated ground tunnel wall.

The front gripper 16 includes a plurality of front grippers 16 arranged at predetermined intervals along a circumferential direction, and has a built-in jack for expanding and contracting the gripper plate toward the excavated pit wall. An electromagnetic relief valve R3 for controlling pressure is provided.

Two independent first and second rear body parts 1
The two extensible first and second main grippers are independent of each other and take up a reaction force by pressing against the inner surface of the pit wall when excavating the ground with the cutter head 15. 17 and 18 are provided.

First and second main grippers 17, 18
In the same manner as the front gripper 16, a jack for expanding and contracting the gripper plate toward the excavated pit wall is built in, and first and second electromagnetic relief valves R1, R2 for controlling the pressure of each jack are provided. Is provided.

At the rear end of the second rear body portion 18, when the ground level is bad, a shield hook for excavating the main body portion 10 by taking a reaction force against a support (not shown) installed behind the shield portion when the ground is bad. 21 are provided.

Between the front body 11 and the first rear body 12,
A first thrust jack 19 for advancing the front body 11 is provided, and a second thrust jack 20 for advancing the front body 11 is provided between the front body 11 and the second rear body 13. .

The drive motor of the cutter head 15 measures a supplied current to obtain a cutter torque sensor S1 for obtaining a rotation torque T of the cutter head 15, and a cutter rotation speed sensor S2 for measuring a rotation speed R of the cutter head 15. Are provided.

The reference numeral 30 in FIG. 1 is a control circuit for the drive motor. The first and second thrust jacks 19 and 20 are provided with hydraulic pressure supplied to the jacks.
Thrust sensors S3, S5 for obtaining thrust W by the respective thrust jacks 19, 20;
Jack stroke sensors S4 and S6 for obtaining the excavation length l from the movement amount of 0 are provided, and the excavation speed V is obtained from the excavation length l per unit time.

The shield jack 21 has a thrust Ws by the shield jack 21 from the hydraulic pressure supplied to the jack.
Is provided, and a jack stroke sensor S8 for obtaining the excavation length ls from the movement amount of the shield jack 21 is provided. The excavation speed Vs is obtained from the excavation length ls per unit time.

However, the excavation by the shield jack 21 is limited to the case where the excavation by the thrust jacks 19 and 20 is difficult or impossible because the ground is particularly bad. in this case,
In the double gripper TBM machine of the present embodiment, when a part of the reaction force to the thrust thrust is shared by the invert or the all-around liner installed at the rear of the main body 10, the thrust at the time of pulling of the rear trunks 12 and 13 is increased. In some cases, the jacks 19 and 20 and the shield jack 21 are used in synchronization with each other, and the reaction force can be measured by the shield jack thrust sensor S7.

Although not shown in the figure, a pitching meter and a rolling meter for grasping the posture of the main body 10, a gyro compass for grasping the azimuth or position, a level meter, an encoder, a laser transit, an automatic tracking total station, etc. , A sensor capable of continuously grasping the posture and position of the TBM, an instrument, a sequencer for controlling the instrument, a computer, and the like.

On the rear side of the main body 10, a computer 32 for excavation control is provided.
While the measurement values of the sensors S1 to S8 are input,
The computer 32 receives the measured values of the sensors S1 to S8, calculates the strength σ of the ground to be excavated, and excavates with one set of grippers and thrust jacks based on the ground strength σ. In between, the other set of grippers,
Select one of a continuous excavation mode in which the thrust jack is contracted to perform excavation preparation and the excavation and excavation preparation are alternately repeated, or a synchronized excavation mode in which two sets of grippers and a thrust jack are simultaneously driven. And a program for sending a control signal to each of the relief valves R1 to R3 and the first and second thrust jacks 19 and 20.

FIG. 2 shows another double gripper TBM machine to which the excavation method of the present invention is applied, and the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals.

The machine shown in FIG. 1 is an open type machine. Reference numeral 10 denotes a main body of the machine, and the main body 10 includes a main beam 14. Parts are placed.

At the tip of the main beam 14, a cutter head 15 for excavating the ground is arranged. In addition, the two sides of the center and the rear side of the main beam 14 are two independent two sides which come into contact with the inner surface of the pit wall and take a reaction force by pressing this when excavating the ground with the cutter head 15. Telescopic first and second main grippers 17, 18 are provided.

First and second main grippers 17, 18
Has a built-in jack for expanding and contracting the gripper plate toward the excavated pit wall, and first and second electromagnetic relief valves R for controlling the pressure of each jack.
1, R2 are provided.

A rear part (not shown) for supporting the main beam 14 when the first and second main grippers 17 and 18 are drawn is provided at the rear portion of the main beam 14.

Main beam 14 and first main gripper 1
7, a first thrust jack 19 for advancing the main beam 14 is provided.
A second thrust jack 20 for advancing the main beam 14 is provided between the fourth main gripper 18 and the support portion.

The drive motor of the cutter head 15 is provided with a cutter torque sensor S1 for obtaining the rotation torque T of the cutter head 15, and a cutter rotation speed sensor S2 for measuring the rotation speed R of the cutter head 15.

The reference numeral 30 in FIG. 2 is a control circuit for the drive motor. The first and second thrust jacks 19 and 20 are provided with hydraulic pressure supplied to the jacks.
Thrust sensors S3, S5 for obtaining thrust W by the respective thrust jacks 19, 20;
Jack stroke sensors S4 and S6 for obtaining the excavation length l from the movement amount of 0 are provided, and the excavation speed V is obtained from the excavation length l per unit time.

Although not shown in FIG. 2, a pitching meter, a rolling meter for grasping the attitude of the main body 10, a gyro compass for grasping the bearing or position, a level meter, an encoder, a laser transit, an automatic tracking total station, etc. , A sensor capable of continuously grasping the posture and position of the TBM, an instrument, a sequencer for controlling the instrument, a computer, and the like.

A computer 32 for excavation control is provided on the rear side of the main body 10.
While the measurement values of the sensors S1 to S6 are input,
The computer 32 receives the measurement values of the sensors S1 to S6, calculates the strength σ of the ground to be excavated, and excavates with one set of gripper and thrust jack based on the ground strength σ. In between, the other set of grippers,
Select one of a continuous excavation mode in which the thrust jack is contracted to perform excavation preparation and the excavation and excavation preparation are alternately repeated, or a synchronized excavation mode in which two sets of grippers and a thrust jack are simultaneously driven. And a program for transmitting a control signal to each of the relief valves R1 to R3 and the first and second thrust jacks 19 and 20 are incorporated.

FIG. 3 shows an example of a control procedure performed by the excavation control computer 32. When the procedure starts, the ground is actually excavated. At this time, excavation is performed by adjusting the cutter rotation speed R and the excavation speed V so that the cutter torque T and the thrust thrust W acting on the cutter head 15 are respectively equal to or less than preset limit values (step s100).

In the following step s101, each sensor S
The measured values of 1 to S8 are input, and the cutter torque T, the cutter rotation speed R, and the excavation speed V obtained at the time of the excavation are calculated, and from the previously measured face area (excavation cross-sectional area) A, the actual value is calculated. Excavation ground strength σ is estimated (step s102).

The ground strength σ has a close relationship with the unit excavation energy e. In general, the larger the energy e, the harder the rock, and the smaller the energy e, the softer the rock.

The unit excavation energy is e = W / Ac + 2
It can be obtained from the equation of π (T / Ac) (R / V). Note that the ground strength σ can be estimated by a load test or a pushing amount test using a gripper, in addition to being obtained from the above-described relational expression.

Next, it is determined in step s103 whether or not the obtained ground strength σ is between predetermined ground strengths σ1 and σ2. In this case, the ground strength σ1
Is a value corresponding to the strength of the collapsed ground and the expansive ground, and the ground strength σ2 is a value corresponding to the strength of the cemented rock ground.

If it is determined in step s103 that the ground strength σ is not between σ1 and σ2, in step s104,
First and second member grippers 17, 18 and first and second members
A control signal for simultaneously expanding and contracting the thrust jacks 19 and 20 is transmitted from the computer 32, and excavation is performed in the synchronous excavation mode.

On the other hand, if it is determined in step s103 that the ground strength σ is between σ1 and σ2, step s10
At 5, the first main gripper 17 takes a reaction force, and the first
The thrust jack 19 propells the second main gripper 18 and the second thrust jack 2 during the propulsion.
0 is contracted, the second rear trunk 13 is drawn toward the first rear trunk 12 to prepare for excavation, and a control signal for alternately performing such an operation is transmitted from the computer 32, and the continuous excavation mode is performed. Excavation is performed.

After the selection of the excavation mode, the process returns to step s101, and excavation is continued in the same procedure.

According to the above-described excavation method, the synchronous excavation mode is selected when the excavated ground is a collapsible ground, an expansive ground, or a cemented rock ground. , Since continuous excavation mode is selected, when excavation is carried out in synchronized excavation mode in collapsed ground and expansive ground, necessary thrust and contraction force can be secured even if collapsed sediment is caught between trunks. it can.

Further, when the excavation is performed in the coherent rock excavation mode in the cemented rock mass, a decrease in excavation speed can be reduced.

Furthermore, since the excavated ground, the expansive ground, and the hard rock ground are excavated in the continuous excavation mode, the superiority of this excavation method can be effectively used.

Table 1 below shows the results of trial calculations performed to confirm the effects of the excavation method of the present invention. In this calculation, the unit is not specified for each value.
Since each of these values changes depending on the rock condition and the excavation diameter of the TBM, it is indicated as an index that is easy to understand intuitively.

The excavation mode is assumed to be of three types: a hard rock excavation mode, a continuous excavation mode, and a soft rock excavation mode. The ground strength was 800 to 50 and a value for comparing each mode.

The unit digging speed thrust is expressed by the unit digging speed of TB
This is the thrust thrust at which the maximum value of the slip-out capability of M is 1 and the excavation speed is obtained. In this calculation, the ground strength is 10
When it is 0 or more, the unit excavation speed thrust is set to the same value as the ground strength, and when the ground strength is less than 100, it is set to 100. this is,
Consideration is given to the increase in thrust due to poor crushing and incorporation of soft rocks and poor uptake of shells.

In the continuous excavation mode, the front and rear thrust jacks operate independently and alternately.
It will be the same as one of the thrusts. In the hard rock excavation mode and the soft rock excavation mode, since the front and rear thrust jacks operate in synchronization, the total thrust of both is obtained.

The maximum thrust of one set of thrust jacks is
In the continuous excavation mode, the maximum value of the thrust during excavation is 400, and in the cemented rock excavation mode and the soft rock excavation mode, the maximum value is 800, which is twice as large.

However, even if a thrust higher than the unit excavation speed thrust is applied, the maximum value 1 of the slip-out ability cannot be exceeded. In the continuous excavation mode, the front and rear main gripper reaction forces independently and alternately act on the gripper, so that the value becomes equal to one of the values.

In the hard rock excavation mode and the soft rock excavation mode, since the front and rear main grippers operate in synchronization, the total of the two becomes the reaction force during excavation. The maximum value of the reaction force of one set of the main grippers is 1200, and the maximum value of the thrust at the time of excavation is 1200 in the continuous excavation mode, and 2400 times that of the maximum in the hard rock excavation mode and the soft rock excavation mode.
Becomes

However, with a set of main grippers, if a reaction force greater than that limited by the ground strength is applied, the main gripper collapses and cannot be applied to a predetermined value or more.

In this estimation, the predetermined value is set to be three times the ground strength. In this calculation, the relationship between the thrust thrust and the gripper reaction force was determined to require three times the thrust thrust during excavation as the gripper reaction force.

The operation rate was set to 1 in the continuous excavation mode, and set to 0.8 in the cemented rock excavation mode and the soft rock excavation mode in consideration of the refilling time (jack drawing time).
Here, other operations such as the assembling time of the shoring work are not considered at all.

The excavation speed was set as follows: operation rate = thrust thrust / unit excavation speed thrust, and the results in each mode were compared using the operation rate × excavation speed.

[0058]

[Table 1] In Table 1 above, when the operating rate × the excavation speed is compared, it can be seen that the cemented rock excavation mode is larger than the continuous excavation mode at the ground strength 800, the same at 500, and smaller at 40.

Further, it can be seen that the continuous excavation mode is larger than the cemented rock excavation mode at the ground strength of 100, is the same at 80, and is smaller at 50.

That is, when the ground strength is 500 or more, the cemented rock excavation mode is efficient, and in the range of 500 to 80, the continuous excavation mode is efficient. It can be said that it is efficient.

Note that the trial calculations in Table 1 above are comparisons in the simplest case. In practice, many factors have a complex effect depending on the site conditions, and other than the pressure and selection timing of the thrust jack and the main gripper. In addition, it is necessary to consider the range of application of the cutter drive motor, cutter head opening, and roller cutter to the ground strength. In accordance with the synchronous excavation mode (hard rock excavation mode,
Excavation in the soft rock excavation mode) is certain to enable efficient excavation with economical TBM.

[0062]

As described above in detail in the embodiments,
According to the excavation method of the tunnel boring machine according to the present invention, by selecting the excavation mode according to the strength of the excavation target ground, while ensuring the thrust for excavation, and,
The advantage of the continuous excavation mode can be effectively used.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a double gripper type TBM machine in which a digging method according to the present invention is adopted.

FIG. 2 is an explanatory view showing another example of a double gripper type TBM machine employing the excavation method according to the present invention.

FIG. 3 is a flowchart illustrating an example of a procedure of a digging method performed by the TBM machine of FIGS. 1 and 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Main body part 11 Front trunk part 12 1st rear trunk part 13 2nd rear trunk part 14 Main beam 15 Cutter head 16 Front gripper 17 1st main gripper 18 2nd main gripper 19 1st thrust jack 20 2nd thrust jack 32 Excavation Control computer S1 Cutter torque sensor S2 Cutter rotation speed sensor S3 First thrust jack thrust sensor S4 First thrust jack stroke sensor S5 Second shield jack thrust sensor S6 Second shield jack stroke sensor

Claims (5)

[Claims] 1. An excavating preparation is provided by providing two sets of independent thrust jacks and grippers, and while excavating with one set of grippers and thrust jacks, contracting the other set of grippers and thrust jacks. A tunnel boring machine for excavating in a continuous excavation mode in which the excavation and the excavation preparation are alternately repeated. In addition to the continuous excavation mode, a synchronized excavation mode for simultaneously driving the two sets of grippers and thrust jacks And selecting one of the continuous excavation mode and the synchronous excavation mode in accordance with the strength of the excavation target ground. 2. The method for excavating a tunnel boring machine according to claim 1, wherein the synchronous excavation mode is selected in the case of a collapsed ground, an expansive ground, and a hard rock ground. 3. The soil strength is determined by installing sensors for measuring a cutter torque, a thrust, a digging speed, and a cutter rotation speed in a tunnel boring machine, and excavating a unit volume based on a detection value of the sensors. The excavation method for a tunnel boring machine according to claim 1 or 2, wherein a unit excavation energy consumed for the excavation is calculated and estimated based on the unit excavation energy. 4. The rotation torque obtained from the cutter torque sensor is T, the thrust thrust obtained from the thrust sensor is W, the excavation speed obtained from the stroke sensor is V, the cutter rotation speed obtained from the cutter rotation speed sensor. Where R is the excavation time, l is the excavation length, l is the face area of the tunnel boring machine, and A is the total energy E consumed by the tunnel boring machine to excavate rock. e is obtained by the following equation: e = E / (Al) = (W1 + 2πTRt) / (Al) = W / A + 2π (TRt) / (Al) = W / A + 2π (T / A) (R / V) The ground strength at the time of excavation by a tunnel boring machine is estimated based on the unit excavation energy e obtained from the above. Excavation method of the tunnel boring machine described. 5. The tunnel boring machine excavating method according to claim 1, wherein the tunnel boring machine is selected from a shield type or an open type.