JP4281983B2 - Tunnel excavation method using advanced shaft - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tunnel excavation method that improves the efficiency of excavation of main shafts and eliminates congestion of construction machinery by using an advanced guide shaft excavated in front of the face in the cross section of the main shaft.
[0002]
[Prior art]
Conventionally, the excavation method of a mountain tunnel includes a full-section excavation method that excavates a design section at once, a full-section method with an auxiliary bench, a long bench cut that excavates into an upper half section and a lower half section of the design section, Bench cut methods such as short bench cut, mini bench cut, etc., and the side wall shaft advanced method that excavates the upper half section after the side wall shaft is advanced on the side wall in the design section (hereinafter collectively referred to as the conventional method). ), And a suitable excavation method is appropriately selected according to the natural ground properties and the cross-sectional shape of the tunnel.
[0003]
On the other hand, in tunnels with a large amount of spring water, it is difficult or impossible to secure high-quality construction of spray concrete and rock bolts as support members. May be excavated in advance. The pilot shaft is a small section of a tunnel formed prior to the main shaft excavation inside and outside the design cross section of the tunnel main shaft for both drainage and geological surveys, and the side wall shaft also serves as the pilot shaft May be adopted.
[0004]
[Problems to be solved by the invention]
In the conventional method, the excavation procedure basically includes face drilling, charge, blasting, slipping, spraying (in some cases, steel arch support is also built), rock bolt drilling and punching. Drilling is carried out sequentially according to the installation procedure. Each of these processes is difficult to carry out in parallel due to the fact that the construction machines used differ depending on the type of work and that it is difficult to parallel the construction machines at many tunnel cross sections except large cross sections. It was a factor that shortened the cycle process time and consequently could not improve the efficiency of tunnel excavation.
[0005]
Also, in large-section tunnels, etc., rock bolt drilling / placement and face drilling / charging are performed simultaneously with the drill jumbo aligned in front of the face, but the installation interval of construction machines is limited. In the case of a narrow space, there has been a concern that a contact accident such as a boom or an accident involving an operator due to congestion between machines may occur.
[0006]
Furthermore, in the case of unsatisfactory ground such as collapsible ground, it is desirable to construct a support by blowing and rock bolting (in some cases, a steel arch support is also provided) at an early stage after blast excavation. However, since the work space is occupied by the slip loading machine and the dump truck, there is a problem that it is impossible to enter the face until the slip is finished.
[0007]
Therefore, the main problem of the present invention is that in a tunnel excavation method in which an advanced guide shaft is formed in the main shaft design section prior to main shaft excavation, the spraying operation or the rock bolt operation can be performed in parallel with the slipping operation. To shorten the excavation cycle time, and to be able to quickly respond to defective ground by making it possible to start supporting construction work immediately after blasting, and further, congestion between construction machines This is to eliminate the accidents of contact between machines and injury to workers and to enable safe excavation.
[0008]
[Means for Solving the Problems]
In the first invention for solving the above-mentioned problem, after forming an advanced guiding shaft in the design section of the main shaft prior to the face excavation of the main shaft, a sprayer is installed in the advanced guiding shaft. ,
After the blasting of the main mine, in parallel with the slippage work in the main mine, the spraying machine located in the advanced guiding mine is positioned at the wellhead of the advanced guiding mine, and on the tunnel wall of the main mine newly exposed by the blasting On the other hand, the spraying work is performed.
[0009]
In addition, the second aspect of the present invention is that after forming an advanced guide prior to the face drilling of the main shaft in the design cross section of the main shaft, a drill jumbo equipped with a drilling boom is installed in the advanced guide shaft,
After blasting Honko, after spraying the spray device located on the downhole, and parallel to the muck working with the underground, the drilling jumbo the advanced pilot tunnel wellhead located in the developed conductive downhole It is positioned, and rock bolt drilling and driving work is performed on the tunnel wall surface of the main mine.
The operation of the sprayer or the drill jumbo installed in the advanced guide shaft is preferably a remote operation because it is difficult for workers to enter.
[0010]
In these cases, it is desirable to form the advanced guide shaft at a substantially upper center position in the cross section of the main shaft design, and it is desirable to construct it by a tunnel boring machine from the viewpoint of construction efficiency. The excavation of the main mine may be blast excavation or mechanical excavation. However, mechanical excavation excludes full-section excavators such as tunnel boring machines and applies to free-section excavators called boom headers and cutter heads. In this machine excavation, the gaps are sequentially discharged from the gap conveyor on the back of the machine at the same time as excavation, but especially in large section tunnels, the face is divided into an excavation area and a spray or rock bolt work area to prevent interference between machines. In addition, the efficiency of the excavation work can be improved by performing the spraying work or the rock bolt drilling and driving in parallel with the slipping work performed simultaneously with the excavation.
[0011]
In the present invention, an advanced guide shaft that has not been used at all in the past is used to perform a spraying operation or a rock bolt driving operation on the tunnel wall surface of the main shaft. In other words, a support construction machine such as a sprayer or drill jumbo is installed in the advanced guiding pit excavated prior to the main mine excavation for the purpose of drainage pits and geological surveys. At the time of slipping out, in parallel with this slipping out work, the support construction by the spraying or lock bolt is performed by the supporting construction machine. As a result, the spraying work or rock bolt drilling / placement work that was previously only possible after waiting for slippage can be performed in parallel with the slippage, thus shortening the drilling cycle time and excavation efficiency. Will improve.
[0012]
Conventionally, support construction work such as spraying and rock bolts could not be done unless the work of slipping out was completed after blast excavation, but it was possible to construct support immediately after blasting, resulting in bad ground, collapse Even if it is a natural ground, etc., it will be possible to construct efficiently while suppressing the loosening of the ground quickly.
[0013]
Furthermore, conventionally, in the mini-bench cut method for large-section tunnels, for the sake of efficiency, two drill jums are placed in parallel in the main mine, and rock bolt drilling / placement and face drilling / charging are performed in parallel. Or two sprayers are arranged in parallel, but when the installation interval of these construction machines is narrow, there is concern about interference between machines or accidents involving workers. It had been. However, in the present invention, drill jumbo for drilling and setting of spray machines and rock bolts is located in the advanced guide shaft, so there is no congestion between construction machines and it is possible to work safely and efficiently. . Of course, even if the tunnel space is large, for example, even if two construction machines are installed and construction can be performed while ensuring contact accidents and safety, it is possible to use a sprayer or drill jumbo installed in the advanced shaft. The work can be efficiently performed by assisting the spraying or drilling work.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the embodiment of the present invention is divided into a first embodiment in which the spraying operation is performed in parallel with the slipping out and a second embodiment in which the lock bolt drilling / placement operation is performed in parallel with the slipping out. Will be described in detail.
[First embodiment]
FIG. 1 is a construction flow diagram of a tunnel excavation method according to the present invention, and FIG. 2 is a cross-sectional view of the tunnel.
[0015]
As shown in FIG. 2, the tunnel targeted by this tunnel excavation method is a tunnel in which an advanced guiding shaft P such as a pilot shaft is formed in the design section of the main shaft 1 prior to the main shaft excavation. . The advanced guide pit P is a small-section tunnel excavated prior to the main mine 1 for the purpose of draining water and geological surveys, and the excavation position is in a state where a sprayer 7 described later is located. Is preferably formed at the approximate center position of the upper half X, and at the center upper position when viewed from the tunnel cross section, so that the excavation method is for the purpose of efficiency other than the conventional blasting method. It can be formed by a tunnel boring machine or the like. The bottom plate portion of the advanced guiding pit P is leveled with earth and sand 11 so that the sprayer 7 can travel.
[0016]
On the other hand, in the main mine 1, a support is constructed by spraying material 2 such as mortar or concrete sprayed on the wall surface during excavation and rock bolts 3, 3. . In some cases, a steel arch member is used in combination.
[0017]
In this example, a large-section tunnel, specifically a construction example of 100 m ² or more, particularly 140 m ² or more, is shown. Therefore, the excavation method has a design section of upper half X, lower half large back Y, and lower Divided into semi-horizontal Z and Z, the upper half X and lower half large back Y are constructed with two drill jums, and the lower half flat Z and Z are constructed with other drill jums (not shown) ) The advantage of this excavation method is that when blasting out the upper half X and lower half large back Y, the lower half soils Z and Z are left on both sides, so it collapses even on unstable ground It is in the point that it is possible to perform the tunnel excavation safely without causing. Of course, there are cases where excavation is carried out without making the lower half flats Z, Z, etc., even if the ground is good even with a large cross section. The excavation method can be applied to a full-section excavation method, a long bench cut method, a short bench cut method, and the like in addition to the mini bench cut method.
[0018]
The tunnel excavation method will be described in detail below according to the excavation procedure. In the following description, the excavation procedure for the lower half soils Z and Z follows the normal excavation procedure, and thus the description thereof is omitted.
[0019]
This tunnel excavation method is the conventional excavation cycle process shown in FIG. 13 in the order of charge drilling → charge → blasting → slipping → spraying → rock bolt drilling / placement in the order shown in FIG. As shown in the construction flow diagram, the spraying machine 7 installed in the advanced guiding pit P enables the parallel work of the slipping work and the spraying work after blasting.
[0020]
First, as shown in FIG. 3, two drill jumbo 4 are positioned in front of a mini bench (lower half large Y) of about 3 to 4 m in the tunnel direction existing below the face. And As the drill jumbo 4, it is desirable to use a drill jumbo provided with at least two charging gauges 6L and 6R as well as at least two drilling booms 5L and 5R in view of work efficiency.
[0021]
An operator who has entered the charging gauges 6L and 6R marks the upper half X with a blast hole, and after marking the lock bolt hole on the upper half tunnel wall, from the face of the upper half X While drilling the charge hole in the forward direction, the lock bolt hole is drilled.
[0022]
Next, as shown in FIG. 4, the drill jumbo 4 is set back by several meters, and the locking bolts 3, 3... In parallel, drilling of the charge hole is performed on the lower half large back Y. Thereafter, dynamite is charged to the blast hole of the upper half X, and dynamite is charged to the lower half large back Y.
[0023]
When the blasting preparation is completed, the dynamite loaded in the upper half X and the lower half large back Y is exploded to break the face and form a new upper half face and a lower half large face. After the blasting, as shown in FIG. 5, the sand load is removed by the wheel loader 8 and the dump truck 9 located in the main mine, and the sprayer 7 installed in the advanced mine shaft P is used as the advanced mine shaft. It is located in P wellhead part, turning while turning a nozzle toward the upper half, and spraying material 2 such as mortar or concrete is sprayed on the newly exposed tunnel wall surface. In addition, the steel arch member is installed together as necessary. The nozzle operation of the sprayer 7 is desirably remote operation because it is difficult for workers to enter, and since it is difficult to supply the spray material from the advanced guide shaft P, the lower half The spraying material is supplied from a spraying machine 20 with a pump for spraying the earth Z and the Z part, or is supplied by a spraying material pump (not shown) separately installed in the main mine.
One cycle of the excavation process is completed through the above steps. Thereafter, this excavation cycle is repeated, and the tunnel is extended sequentially.
[0024]
[Second embodiment]
Next, a detailed description will be given with reference to FIGS. 7 to 12 with respect to a second embodiment in which the slippage after blasting and the lock bolt drilling and driving work for the upper half tunnel wall surface are performed in parallel.
[0025]
As shown in the construction flow diagram of FIG. 7, the drill jumbo 4 performs only the drilling of the charge holes for the upper half X face and the lower half large back Y face, and the blasting machine located in the main mine after blasting After the spraying by 12, the slippage and the rock bolt drilling and placing work on the upper half tunnel wall surface are performed in parallel.
[0026]
First, as shown in FIG. 8, preferably one or two drill jumbo 4 are placed in front of a mini-bench (lower half large Y) having a length of about 3 to 4 m in the tunnel direction on the lower side of the face. The position is assumed to be set. An operator who has entered the charging gauges 6L and 6R marks the upper half X with a blast hole, and then drills the charge hole in the forward direction from the face of the upper half X.
[0027]
Next, as shown in FIG. 9, the drill jumbo 4 is in a state of being retracted by several meters, and the charging hole is drilled in the lower half large back Y. Thereafter, dynamite is charged to the blast hole of the upper half X, and dynamite is charged to the lower half large back Y.
[0028]
When the blasting preparation is completed, the dynamite loaded in the upper half X and the lower half large back Y is exploded to break the face and form a new upper half face and a lower half large face. Immediately after blasting, as shown in FIG. 10, the blasting material such as mortar or concrete is blown against the newly exposed upper half tunnel wall surface by the sprayer 12 located in the main mine. wear. In addition, the steel arch member is installed together as necessary. After that, when the spraying operation is completed, as shown in FIG. 11, the sand load is removed by the wheel loader 8 and the dump truck 9 located in the main mine, and the lock installed in the advanced guide pit P The bolt drill jumbo 10 is positioned at the advanced guide P pit, drilling the lock bolt hole while turning the boom, and the operator who has entered the charging cage performs the operation of driving the lock bolt. As shown in the figure, the rock bolt drill jumbo 10 is preferably provided with two drilling booms 13L and 13R so as to perform drilling while sharing the upper right half and the upper left half respectively. It is desirable to have a charging bolt 14 and preferably two to three charging gauges 14 for the purpose of driving a rock bolt. In addition, since the boom operation of the rock bolt drill jumbo 10 is difficult for an operator to enter, as in the case of the sprayer 7, it is desirable to perform the remote operation.
[0029]
If the installation work of the said rock bolt is completed, the excavation process of 1 cycle will be completed, and after that, this excavation cycle is repeated and a tunnel is extended sequentially.
[0030]
【The invention's effect】
As described in detail above, according to the present invention, in the tunnel excavation method in which the advanced guide shaft is formed in the main shaft design section prior to the main shaft excavation, the spraying operation or the lock bolt operation is performed in parallel with the slipping operation. This will allow the excavation cycle time to be shortened. In addition, support construction work can be started as soon as possible immediately after blasting, so that it is possible to quickly cope with defective ground. Furthermore, the congestion between the construction machines is eliminated, and there is no contact accident between the machines and no human injury.
[Brief description of the drawings]
FIG. 1 is a construction flow diagram of a tunnel excavation method according to the first embodiment.
FIG. 2 is a cross-sectional view of a tunnel.
FIG. 3 is a longitudinal sectional view showing a tunnel excavation procedure (part 1).
FIG. 4 is a longitudinal sectional view showing a tunnel excavation procedure (No. 2).
FIG. 5 shows a tunnel excavation procedure (No. 3), (A) is a longitudinal sectional view, and (B) is a plan view.
6 is a view taken in the direction of arrows VI-VI in FIG. 5;
FIG. 7 is a construction flowchart of the tunnel excavation method according to the second embodiment.
FIG. 8 is a longitudinal sectional view showing a tunnel excavation procedure (part 1).
FIG. 9 is a longitudinal sectional view showing a tunnel excavation procedure (No. 2).
FIG. 10 is a longitudinal sectional view showing a tunnel excavation procedure (No. 3).
FIG. 11 shows a tunnel excavation procedure (No. 4), (A) is a longitudinal sectional view, and (B) is a plan view.
12 is a view taken in the direction of arrows XII-XII in FIG.
FIG. 13 is a construction flow diagram of conventional tunnel excavation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Main mine, 2 ... Spraying material, 3 ... Rock bolt, 4 ... Drill jumbo, 7 ... Spraying machine, 8 ... Wheel loader, 9 ... Dump truck, 10 ... Drill jumbo for rock bolt, P ... Advanced guide shaft

Claims (4)

After forming the advanced guiding pit in advance of the main pit face excavation in the design cross section of the main mine, a spraying machine is installed in the advanced guiding mine,
After the blasting of the main mine, in parallel with the slippage work in the main mine, the spraying machine located in the advanced guiding mine is positioned at the wellhead of the advanced guiding mine, and on the tunnel wall of the main mine newly exposed by the blasting A tunnel excavation method using an advanced guideway characterized by spraying work. In the design section of the main mine, after forming the advanced guiding pit prior to the main pit face excavation, a drill jumbo equipped with a drilling boom is installed in the advanced guiding pit,
After blasting Honko, after spraying the spray device located on the downhole, and parallel to the muck working with the underground, the drilling jumbo the advanced pilot tunnel wellhead located in the developed conductive downhole A tunnel excavation method using an advanced guiding pit characterized in that it is positioned and performs rock bolt drilling and driving work on the tunnel wall of the main mine. The tunnel excavation method using the advanced guide pit according to claim 1, wherein the operation of the sprayer or the drill jumbo installed in the advanced guide mine is remote control. 4. The tunnel excavation method using an advanced guide shaft according to any one of claims 1 to 3, wherein the advanced guide shaft is formed at a substantially upper center side position in a main shaft design section.

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