JPH1193597A - Tunnel support selection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To select supports to be installed on an excavated wall from among multiple kinds of supports on the basis of the number of rock pieces of a prescribed diameter or larger per prescribed length of boring when a rock mass is excavated. SOLUTION: A rock mass is excavated with a cutter blade 1, the number of excavated rock pieces of a prescribed diameter or larger is counted by processing an image projected on a monitor camera 32 while advancing a tunnel excavator, and the number of rock pieces of a prescribed diameter or larger appearing per prescribed length of boring is obtained. When the number of excavated rock pieces is large, on the assumption that the rock mass is soft, strong supports are selected, and selected supports are installed at an excavated wall 20. When the number of excavated rock pieces is small, on the assumption that the rock mass is hard, ring supports 21 are selected and installed at the excavated wall 20. Therefore, appropriate supports can be selected at once for the excavated wall without confirming the excavated wall visually immediately after excavation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method of selecting a tunnel support used for holding a tunnel wall excavated by a tunnel excavator.

[0002]

2. Description of the Related Art Conventionally, in the construction of a tunnel in a collapsed ground, a tunnel excavator (TBM) having a skin plate as an outer shell for supporting an excavation wall surface is used.
Tunnel excavation is taking place. As the support for holding the tunnel wall surface excavated by this tunnel excavator, an appropriate tunnel support is selected in view of the state of cracks and the like on the excavation wall surface exposed behind the skin plate.

[0003]

By the way, according to the above-mentioned method of selecting a tunnel support, when the excavated wall surface has collapsed immediately after excavation until it is exposed behind the skin plate, or immediately after exposure, the above-described method is used. If the support was selected by looking at the state of the excavated wall after exposure, it was not possible to keep the excavated wall in time. It is necessary to take measures to prevent collapse such as bolting, which causes a problem that the entire excavation process is delayed. To solve this,
It is conceivable that several types of support means (ring support, shotcrete casting, sheet pile, rock bolting, etc.) are prepared in advance, and measures are taken immediately after the wall surface is exposed. If it has already collapsed, it cannot be dealt with, and the above-mentioned support means must always be prepared and kept at the site, which hinders the removal of excavated waste and the loading and unloading of equipment, traffic at the time of unloading, It is also unfavorable in construction and working environment.

Accordingly, an object of the present invention is to provide a tunnel support capable of promptly selecting an appropriate support for a wall immediately after excavation without visually checking the excavated wall exposed behind a tunnel excavator to be excavated. It is to provide a selection method.

[0005]

In order to achieve the above object, a method of selecting a tunnel support according to the first aspect of the present invention is characterized in that when rock is excavated by a tunnel excavator, excavated rock fragments having a diameter equal to or more than a predetermined diameter per predetermined excavation length are obtained. On the basis of the number of appearances, a support installed on the excavation wall is selected from a plurality of types of supports.

According to the method for selecting a support for a tunnel according to the first aspect of the present invention, as the rock excavated by the tunnel excavator is softer and the number of excavated rock pieces having the predetermined diameter or more increases, the harder the rock is, The number of excavated rock fragments having a diameter equal to or larger than the predetermined diameter is reduced. Therefore, when the number of excavated rock fragments having the predetermined diameter or more is large, the rock is assumed to be soft, a strong support is selected, and the selected support is installed on the excavation wall surface. When the number of appearances is small, it is assumed that the rock is solid, and a non-support or a ring-support, which is weaker than the strong support, is selected, and the selected support is installed on the excavation wall surface except in the case of no support. Therefore, it is possible to quickly select an appropriate support for the wall immediately after excavation without visually confirming the wall excavated by the tunnel excavator, and it is not necessary to prepare all types of supports on site.

According to a second aspect of the present invention, there is provided a method for selecting a support for a tunnel, wherein a plurality of types of supports are provided by observing an excavated wall surface exposed behind the tunnel excavator when the rock is excavated by a tunnel excavator. A first step of installing the support selected from the above on the excavation wall surface and obtaining the number of appearances of excavated rock fragments having the predetermined diameter or more per the predetermined excavation length, and a result of repeating the first step a plurality of times. A second step of creating a table that defines the relationship between the type of the selected support and the number of excavated rock fragments having a diameter equal to or greater than the predetermined diameter, and the tunnel excavator based on the created table. And selecting a support to be installed on the excavation wall according to the number of excavated rock pieces having the predetermined diameter or more per the predetermined excavation length obtained by excavation. That.

According to the method for selecting a support for a tunnel according to the second aspect of the present invention, when a rock is excavated by a tunnel excavator,
By observing the excavation wall surface exposed behind the excavating tunnel excavator, an appropriate support is selected from a plurality of types of supports, the selected support is installed on the excavation wall, and a predetermined excavation at this installation position is performed. The number of occurrences of excavated rock fragments of a predetermined diameter or more per length is obtained, and the number of occurrences of excavated rock fragments of a predetermined diameter or more per predetermined excavation length is repeatedly determined a plurality of times while the support is installed. A table is created that defines the relationship between the type of rock and the number of excavated rock fragments having a diameter equal to or more than a predetermined diameter per predetermined drilling length at the installation position of the support. Then, based on the table created above, select a support to be installed on the excavation wall according to the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length obtained by excavating the tunnel excavator. Then, install the selected support on the excavation wall. At this time, when there is a large number of excavated rock pieces having a diameter equal to or more than the predetermined excavation length, the rock is soft and a strong support is selected, whereas the rock having a diameter equal to or more than the predetermined diameter per excavation length is selected. When the number of excavated rock fragments is small, the rock is hard and a non-support or a ring support, which is weaker than the strong support, is selected. Therefore, it is possible to quickly select an appropriate support for the wall immediately after excavation without visually confirming the wall excavated by the tunnel excavator, and it is not necessary to prepare all types of supports on site.

A third aspect of the present invention provides a method of selecting a tunnel support according to the second aspect.
In the first and second steps, a plurality of the tables are prepared for each type of rock, and in the third step, the rock surface is observed by observing the excavated wall surface exposed behind the excavating tunnel excavator. The type is determined, the table corresponding to the determined rock type is selected from the plurality of tables, and the predetermined table obtained by excavating the tunnel excavator based on the selected table is selected. The present invention is characterized in that a support corresponding to the number of appearances of excavated rock fragments having the predetermined diameter or more per excavation length is selected.

According to the third aspect of the present invention, in the first step, the excavation wall surface is visually inspected in the first step.
By observing with a blow (waveform or sound) and a probe (penetration), the type of rock is determined based on characteristics such as hard / soft, sticky / friable, etc. The number of the excavated rock pieces having a diameter not less than a predetermined diameter is obtained, and the type of the support selected at the time in the second step and the number of the excavated rock pieces having the predetermined diameter or more per the predetermined excavation length at the installation position of the support are determined. Create a table that defines the relationship with each rock type. Then, a table corresponding to the type of rock is selected, and a support to be installed on the excavation wall is selected based on the number of appearances of excavated rock pieces having a predetermined diameter or more per predetermined excavation length based on the selected table. I do. In other words, in the case of a type of hard rock (or sticky rock), the number of excavated rock fragments with a predetermined diameter or more per specified excavation length decreases,
In the case of the type of soft rock (or fragile rock), the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length increases, so the type of support to be selected differs depending on the characteristics of the rock. Therefore, by using the table selected according to the type of rock, a more appropriate support can be selected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for selecting a tunnel support according to the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 is a cross-sectional view of a tunnel excavator in which a method of selecting a tunnel support according to an embodiment of the present invention is shown. Reference numeral 1 denotes a circular cutter plate having a plurality of roller cutters 10 mounted on a front surface thereof. Reference numeral 2 denotes a front gripper that is disposed behind the cutter plate 1 and protrudes upward and downward.
Reference numeral 4 denotes a circular partition wall disposed on the rear surface side of the front gripper 2, and 4 denotes a cylindrical skin plate having one end fixed to the partition wall 3. Reference numeral 5 denotes a motor fixed to the partition wall 3 for driving the cutter plate 1 to rotate. Reference numeral 6 denotes a beam member having one end fixed to the partition wall 3 and extending rearward from the skin plate 4. 6, a sliding frame slidably supported in the front-rear direction; 8, a propulsion jack having one end fixed to the sliding frame 7 and the other end fixed to the partition 3; It is a rear gripper that protrudes and protrudes horizontally on both sides. Reference numeral 11 denotes a belt conveyor support frame fixed substantially at the center of the beam body 6,
Reference numeral 12 denotes a belt conveyor whose substantially center is supported by the belt conveyor support frame 11, and which carries out the excavated waste backward from the cutter plate 1 side. In addition, the tunnel excavator includes:
The apparatus includes a stroke meter 31 for measuring a stroke of the propulsion jack 8 and a monitor camera 32 for photographing a shift carried by the belt conveyor 12.

In the tunnel excavator, first, the rear gripper 9 is projected horizontally toward the excavation wall surface 20 to fix the sliding frame 7 to the excavation wall surface 20. When the propulsion jack 8 is extended, the partition 3 to which one end of the propulsion jack 8 is fixed is pushed forward, the cutter plate 1 is pushed forward, and the cutter plate 1 is rotated by the motor 5. Excavate the bedrock ahead. Then, when excavating for a predetermined distance, the extension of the propulsion jack 8 is stopped, the front gripper 2 is projected to the excavation wall surface 20, and the rear gripper 9 is immersed inside. Next, when the propulsion jack 8 is contracted, the sliding frame 7 moves forward together with the rear gripper 9. Next, after the rear gripper 9 is protruded and the front gripper 2 is immersed, the propulsion jack 8 is extended, and the cutter plate 1 is rotated by the motor 5 to excavate the front rock. As described above, while the front gripper 2 and the rear gripper 9 are alternately protruded and retracted, the propulsion jack 8 is moved.
Makes the tunnel excavator excavate. Then, while the tunnel excavator is excavating, the image captured by the monitor camera 32 is subjected to image processing by an image processing device (not shown), and the number of slips having a predetermined diameter or more is counted. Then, based on the excavated length converted from the stroke measured by the stroke meter 31 and the number of counted debris having a predetermined diameter or more, the appearance of debris (excavated rock fragments) having a predetermined diameter or more per predetermined excavation length is performed. Find the number.

The present applicant has examined the relationship between the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length and the type of a tunnel support installed at that position based on past tunnel excavation data. It was found that the larger the number of excavated rock pieces with a predetermined diameter or more per predetermined excavation length, the stronger the support was provided. This means that if a rock has no cracks, it will usually break into a thin plate when drilling with a tunnel excavator.However, the rock fragments are large and clumpy because the rock has cracks. It is. The appearance frequency of large rock fragments is
It is related to the number and depth of cracks. From the viewpoint of setting up the support of the frequency of occurrence of such rock fragments, a strong support is required where cracks are severe. In addition, this is considered to be relative when the type of rock is the same, and depending on the type of rock, the difference in the appearance frequency of large rock fragments due to its characteristics (hard / soft, sticky / fragile, etc.) May be present.

FIG. 3 shows the number of appearances of excavated rock fragments having a predetermined diameter or more per a predetermined excavation length at the time of tunnel excavation and the type of support selected at that time, obtained from actual construction results.
The horizontal axis in FIG. 3 indicates the excavation distance. The types of support to be selected are the following (1) to (4), and (1) to (4)
In this order, the support for holding the excavated wall surface becomes stronger. (1) Unsupported (2) Ring support A (pitch 1m) (3) Ring support B (pitch 0.5m) (4) Ring support + hanging sheet pile

In the ring support A of the above (2), ring supports 21 formed of a steel material having a H-shaped cross section in a ring shape are installed at intervals of 1 m in the direction of excavation, and the ring support B of the (3) Similar ring supports 21 are installed at intervals of 0.5 m. In the ring support and the hanging sheet pile of the above (4), a steel sheet pile 22 is installed on the excavation wall surface 20 above the ring support installed at a predetermined interval in the excavation direction. As described above, as the number of excavated rock pieces having a diameter equal to or more than a predetermined diameter per predetermined excavation length increases, a stronger support is selected to hold the excavated wall surface.

Hereinafter, a method of selecting a tunnel support when excavating by the tunnel excavator will be described.

While excavating with the tunnel excavator, the excavation wall surface 20 (shown in FIG. 1) exposed from the rear of the tail of the tunnel excavator is visually observed, struck (waveform or sound), and observed with a probe (penetration). , Select a support and place the selected support. At this time,
There is no support, ring support, hanging sheet pile, etc. In addition, the number of excavated rock fragments having a predetermined diameter or more per predetermined excavation length when excavating the ground at the installation position of the support is obtained. Then, during the excavation of the tunnel, the data of the selection of the support and the data of the number of the excavated rock fragments having the predetermined diameter or more per the predetermined excavation length are accumulated for a certain period.

The data of the above-mentioned support selection and the data of the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length are accumulated, and the type of the support and the number of appearance of excavated rock pieces having a predetermined diameter or more per predetermined excavation length are accumulated. When the relationship is determined, a table indicating the relationship is created. In this embodiment, as shown in FIG. 2, as the number of excavated rock fragments having a diameter equal to or more than a predetermined diameter per predetermined excavation length gradually increases, other means (for example, steel segments), ring support +
Select a hanging sheet pile (pitch 0.5m and 1m), ring support (pitch 0.5m and 1m) and no support.

Based on the table shown in FIG. 2, the tunnel excavator is used to hold the excavated wall surface from the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length obtained by excavation. Choose the right support.

In this manner, by the steps of
While installing the support while excavating the tunnel excavator, visually determine whether the support selected from the number of appearances of excavated rock fragments having a predetermined diameter or more per the predetermined excavation length is visually determined,
By sequentially correcting the table created by the above, it is possible to increase the accuracy of the support selection.

The above operations (1) to (4) are performed for each type of rock in the tunnel planning line, and a table is prepared according to the type of rock, and a table to be used is selected according to the type of rock to be excavated. For example, rock types include hard rock sandstone, slate and tuff, soft rock conglomerate, limestone and consolidated clay.

Further, in the past tunnel construction, a table is prepared in which the relationship between the type of the above-mentioned support and the number of the excavated rock fragments having a predetermined diameter or more per the predetermined excavation length is determined, and this table is used for new tunnel construction. It can also be applied.

As described above, when the number of the excavated rock pieces having a diameter not smaller than the predetermined diameter per predetermined excavation length is large, the rock is soft and a solid support is selected, and the excavation having the diameter not smaller than the predetermined diameter per predetermined excavation length is selected. If the number of rock fragments is small,
As a solid rock, a non-support or a ring support, which is weaker than the above-mentioned strong support, is selected. Therefore, it is possible to quickly select an appropriate support for the wall immediately after excavation without visually checking the wall excavated by the tunnel excavator, and prepare all types of supports on site. There is no need to provide necessary support according to the selection result.

Further, by observing the excavation wall surface by visual observation, impact (waveform or sound), probe (penetration), or the like, a table is selected from the plurality of tables according to the type of rock, and the selected table is selected. Based on the table, the support is selected according to the number of excavated rock pieces having a diameter equal to or more than a predetermined diameter per predetermined excavation length, so that a more appropriate support can be selected.

In the above embodiment, the type of the support is determined by other means (for example, a steel segment), a ring support and a sheet pile (pitch 0.5 m and 1 m), and a ring support (pitch 0.5 mm).
5m and 1m) and unsupported, but the type of support is of course not limited to these.

[0027]

As is clear from the above, the method of selecting a tunnel support according to the first aspect of the present invention is characterized in that when rock is excavated by a tunnel excavator, the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length is obtained. The support to be installed on the excavation wall is selected from a plurality of types of supports based on the above.

Therefore, according to the method for selecting a support for a tunnel according to the first aspect of the present invention, when the number of excavated rock pieces having a diameter equal to or more than the predetermined diameter is large, the rock is assumed to be soft and a strong support is selected. While the selected support is installed on the excavation wall surface, when the number of excavated rock fragments having a diameter equal to or greater than the predetermined diameter is small, the rock is assumed to be hard, and the unsupported or ring support is weaker than the strong support. Select
Since the selected support is installed on the excavated wall except in the case of no support, an appropriate support can be promptly selected for the wall immediately after excavation without visually confirming the excavated wall. In addition, since it is only necessary to prepare the selected support on site, it is not necessary to prepare all types of support on site.

In the method for selecting a tunnel support according to the second aspect of the present invention, when excavating a bedrock by a tunnel excavator, a plurality of types of excavation walls are exposed by observing an excavated wall surface exposed behind the excavating tunnel excavator. Along with installing the support selected from the supports on the excavation wall surface, and determining the number of excavated rock fragments having a predetermined diameter or more per the predetermined excavation length,
Based on the result of repeating the step of obtaining the number of excavated rock pieces having a diameter not less than a predetermined diameter per predetermined excavation length a plurality of times while installing the support, the type of the selected support and the excavation rock pieces having a diameter not less than a predetermined diameter per predetermined excavation length After creating a table that defines the relationship with the number of appearances, based on the table created above, the number of occurrences of excavated rock fragments with a predetermined diameter or more per predetermined excavation length obtained by excavating the tunnel excavator The support to be installed on the excavation wall is selected accordingly.

Therefore, according to the method for selecting a tunnel support according to the second aspect of the present invention, when the number of excavated rock pieces having a predetermined diameter or more per the predetermined excavation length is large, the rock is considered to be soft and the strong support is provided. Is selected and the selected support is installed on the excavation wall surface, but when the number of excavated rock pieces having a predetermined diameter or more per the predetermined excavation length is small, it is assumed that the rock is hard and the strong support is used. Since a non-support or a ring support, which is weaker than the support, is selected, an appropriate support can be promptly selected for the wall immediately after excavation without visually confirming the excavated wall. In addition, since it is only necessary to prepare the selected support on site, it is not necessary to prepare all types of support on site.

According to a third aspect of the present invention, in the method for selecting a tunnel support according to the second aspect of the present invention, a plurality of the tables are prepared for each type of rock.
The type of rock is determined by observing the excavation wall surface exposed behind the excavating tunnel excavator, and the table corresponding to the determined rock type is selected from the plurality of tables, and the selected table is selected. Based on the table, the support to be installed on the excavation wall is selected in accordance with the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length obtained by excavating the tunnel excavator. By using the selected table, a more appropriate security can be selected.

[Brief description of the drawings]

FIG. 1 is a sectional view of a tunnel excavator in which a method for selecting a tunnel support according to an embodiment of the present invention is used.

FIG. 2 is a diagram showing the relationship between the type of a support to be selected and the number of excavated rock fragments having a predetermined diameter or more per predetermined excavation length.

FIG. 3 is a diagram showing types of supports to be selected with respect to the number of excavated rock fragments having a predetermined diameter or more per a predetermined excavation length obtained from construction results.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cutter plate, 2 ... Front gripper, 3 ... Partition wall, 4 ...
Skin plate, 5 ... Motor, 6 ... Beam body, 7 ... Sliding frame, 8 ... Propulsion jack, 9 ... Rear gripper, 10 ... Roller cutter, 11 ... Belt conveyor support frame, 12 ... Belt conveyor, 20 ... Excavation wall surface, 21 ... Ring support, 22 ...
Yaita, 31: Stroke meter, 32: Monitor camera.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhide Backo 2-2-2 Matsuzakicho, Abeno-ku, Osaka-shi, Osaka Prefecture Okumura Gumi Co., Ltd. (72) Inventor Kamano, etc. 2-chome, Matsuzakicho, Abeno-ku, Osaka-shi, Osaka No. 2-2 Okumura Gumi Co., Ltd. (72) Inventor Shoji Inoue 2-2-2 Matsuzakicho, Abeno-ku, Osaka-shi, Osaka 2-2-2 Okumura Guminai Co., Ltd. (72) Inventor Yoichi Hiroshima 2-Matsuzaki-cho, Abeno-ku, Osaka, Osaka No. 2 No. 2 Okumura Gumi

Claims (3)

[Claims] When a rock is excavated by a tunnel excavator, a support to be installed on an excavation wall is selected from a plurality of types of supports based on the number of excavated rock pieces having a predetermined diameter or more per predetermined excavation length. A method for selecting a tunnel support, which is characterized in that: 2. When excavating rock by a tunnel excavator, a support selected from a plurality of types of supports is installed on the excavation wall by observing an excavation wall exposed behind the tunnel excavator to be excavated. And a first step of obtaining the number of excavated rock fragments having the predetermined diameter or more per the predetermined excavation length, and a type of the selected support and the predetermined number of times based on a result of repeating the first step a plurality of times. A second step of creating a table that defines the relationship between the number of appearances of excavated rock fragments having a diameter or more; and, based on the created table, the predetermined excavation length obtained by excavating the tunnel excavator. And selecting a support to be installed on the excavation wall in accordance with the number of excavated rock pieces having a predetermined diameter or more. 3. The method of selecting a tunnel support according to claim 2, wherein a plurality of the tables are prepared for each type of rock in the first and second steps, and in the third step, excavation is performed. The rock type is determined by observing the excavated wall surface exposed behind the tunnel excavator, and the table corresponding to the determined rock type is selected from the plurality of tables, and the selected table is selected. Selecting a support corresponding to the number of appearances of excavated rock fragments having the predetermined diameter or more per the predetermined excavation length obtained by excavating the tunnel excavator, based on the table, Method.