JP3586500B2 - Excavation method for large section arched tunnel - Google Patents

Description

[0001]
[Industrial applications]
The present invention is particularly even in relatively thin unconsolidated Yuichi mountain like soil breaking, a large cross-section tunnel (large section (drilling sectional area 100-150 ²⁾ to very large cross-section (larger than the excavation cross-sectional area 150 meters ²⁾ The present invention relates to a method for excavating a large-section arched tunnel that enables safe and short-term excavation.
[0002]
[Prior art]
As a method for excavating the large-section arch-shaped tunnel, a proposal by Japanese Patent Publication No. 4-63198 has already been disclosed. In this case, as clearly shown in FIGS. The large-section tunnel 2 to be excavated is driven by the arch-shaped tunnel excavator 5 running on the rail 4 on the lower part 3 to drive the through-groove-excavating chain cutter 6 to form an arch-shaped guide frame. 7, an arched see-through groove 8 is formed in the soft ground 1 a or the like, and a curable material injection pipe 9 separately provided therein is used to form a curable material 9 a as shown in FIG. Is injected, the prelining concrete 10 as an arched support plate is surrounded, and a large-section face 1b surrounded by the prelining is excavated at a time by the full-section method.
[0003]
[Problems to be solved by the invention]
When due to excavation method of the conventional large cross section arcuate tunnels for efficient mechanized construction, but takes the entire cross-section method, in the case of interruption plane tunnel (drilling sectional area 100 m ² or less), the total Although the cross section method is a general method, in the case of a tunnel with a large cross section, it is difficult to secure the independence of the face 1b by ordinary reinforcing works such as mirror spraying and mirror bolts, and the mirror Large-scale reinforcement work will be required for piles and the like. Moreover, since the tunnel cross section is large, the amount of earth and sand to be carried out by one excavation increases, so that the traveling speed of the face 1b is also delayed.
[0004]
Further, a serious problem in the conventional method is that it is considered that the larger the cross-section, the more the stress concentration given to the ground by the lower leg portions on both sides of the prelining concrete 10 is increased. In addition to frequent occurrences of unavoidable situations, it is also anticipated that a situation in which the entire prelining concrete 10 sinks if the implementation time of the reinforcement work is lost late.
[0005]
Therefore, as the reinforcement, invert concrete is cast on the ground near the face 1b, whereby the bases of the two legs of the prelining concrete 10 are continuously provided, whereby a large section is formed between the invert concrete and the prelining concrete. Although it is conceivable that the closing operation is performed earlier by using the step 10, the progress of excavation of the face 1b is further impeded by such a process, and the construction period of the large-section tunnel is prolonged.
[0006]
The present invention is the light of the difficulties of the prior art method, the In the claim 1 without by total cross-sectional method, preliminarily to excavation early advanced central pilot tunnel of tunneling speed, prior on its lower plate portion Invert concrete is cast and if the pre-lining concrete that defines the area in the subsequent large section tunnel is erected, the arch-shaped concrete formed between this and the advanced central shaft Without excavating this pit face once again, once one half was excavated, one base leg of pre-lining concrete and the preceding invert concrete were continuously connected with one side invert concrete. In the same way, after excavating the other half in the same way, the pre-lining concrete, the base of the other side and the preceding inverted concrete were converted to the other side inverted concrete. Ri is to continuously provided.
[0007]
According to the above-described excavation process, in claim 1, by applying the advanced central shaft and the preceding invert concrete, the self-sustainability of the main shaft face in the subsequent prelining concrete forming process is ensured, and the arch is shaped. The first object is to improve the excavation efficiency by reducing the amount of excavated soil of the main shaft face.
[0008]
Furthermore, in the said claim 1, this digging face is not excavated at once by the full-section method, but is excavated in each of the right and left side halves, and the one side invert concrete and the other side invert concrete are cast each time. A second object of the present invention is to make it possible to close the large section as soon as possible, and to complete the large section arched tunnel in a short time without any trouble even in soft ground.
[0009]
Next, in claim 2, in addition to the step of claim 1, after the preceding invert concrete is cast on the lower part of the advanced central shaft, the work is performed by pouring from the advanced central shaft. In forming the pre-lining concrete that defines the large-section tunnel area in the next step, the pre-reinforcement processing with mortar or the like is performed around the foot ground on which both bases of the legs are placed. By laying the bases of the two legs of the prelining concrete on the ground of the reinforcing legs as described above, it is attempted to more effectively prevent the undesired subsidence of the prelining concrete.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, an advanced central shaft is dug by a desired length at a central bottom of a large-section tunnel region to be dug into a required ground. After performing the shaft support or shaft support and pre-assembly auxiliary work for the advanced central shaft, placing the pre-inverted concrete on the lower part of the advanced central shaft, and then on the pre-inverted concrete A rail is laid, and the arched tunnel excavator for the main tunnel face, which is the large section tunnel area, is guided on the rail, and the operation of the arched tunnel excavator causes the arc-shaped through groove excavation to be performed. Using a chain cutter, an arch-shaped see-through groove with an arc-shaped cross section is excavated and filled with hardening material to harden, so that the pre-lining concrete, which is an arch-shaped support plate with an arc-shaped cross section, is formed into an arch shape. Set up Later, after excavating and removing one half of one side of the arched main shaft face between the prelining concrete and the advanced central shaft, the space between the preceding invert concrete and the monopod base of the prelining concrete was removed. Then, one side of the invert concrete is connected continuously, then the other half of the face of the main shaft is excavated and removed, and the preceding invert concrete and the other base of the prelining concrete are connected by the other side invert concrete. In addition, the process from the erecting of the pre-lining concrete to the continuous installation of the other-side invert concrete was repeated, and the inner lining of the pre-lining concrete was appropriately cast with a secondary lining arch concrete. To provide an excavation method for a large arched tunnel characterized by the following features: A.
[0011]
Furthermore, in the method for excavating a large-section arched tunnel according to claim 2, in addition to the configuration according to claim 1, after the preceding invert concrete is cast on the lower part of the advanced central shaft. The advanced central shaft was subjected to a pre-reinforcement process by an injection operation from the advanced central shaft to the periphery of both legs in the large-section tunnel area, and in advance, the ground portion where the prelining concrete should be erected was hardened, Its contents.
[0012]
[Action]
First, when the excavation method of the large section arch type tunnel according to claim 1 is used, the leading advanced central shaft can be excavated in a relatively short time by the free section excavator, and the leading invert concrete is cast therein. By doing so, part of the large-section tunnel is reinforced early in the section. Rails are laid on the preceding invert concrete, thereby guiding the arched tunnel excavator to travel, and by its operation, efficiently filling and curing the curable material in the arched see-through groove. The above-mentioned pre-lining concrete, which is an arch-shaped support plate having an arc-shaped cross section, can be erected so as to be arch-shaped.
[0013]
The next excavation work will be carried out on the arched main shaft face, so the excavated soil volume will be less than the excavated soil volume of the advanced central shaft, and the excavation speed will be quite high. Since the speed of the operation is increased and the pit face is performed for each of the right and left halves, efficient work can be performed. In addition, the invert concrete on one side and the invert concrete on the other side are cast each time, and the large-scale closing of the section is carried out at an early stage. In addition, it becomes possible to efficiently excavate an arched tunnel having a large cross section.
[0014]
According to claim 2, furthermore, after the leading invert concrete is poured into the advanced central shaft, the mortar or urethane can be safely transferred from the advanced central shaft to the ground around the legs of the prelining concrete. , The pre-reinforcement processing is performed on the ground without delay of the process, so that the settlement of the prelining concrete can be more reliably prevented.
[0015]
【Example】
An excavation method for an arched tunnel with a large cross section according to the present invention will be described in detail below with reference to the drawings according to an embodiment. First, as shown in FIG. The large section tunnel 2 is excavated to the required ground 1. The free section excavator (not shown) is advanced by 100 m ahead of the main tunnel face 2 a by the standard method of mountain tunnel excavation (NATM). The advanced central shaft 11 having a cross section of a two-lane road tunnel is excavated by using. This advanced central shaft 11 is to be excavated in the large-section tunnel 2 to be constructed, and at a position which is the central lower part thereof as understood from FIGS. 1 (B), 2 and 3. .
[0016]
Here, as for the above-mentioned advanced central shaft 11, a shaft support must be formed as necessary, and as a means for this, a steel support 12 is built on the inner surface or spraying is performed. It is sufficient to form concrete or drive in a rock bolt. In this case, it is preferable to use a fiber bolt for the lock bolt in consideration of excavation of the main shaft 2a described later.
[0017]
Furthermore, in addition to the above-mentioned support, there is a possibility that the loosened area 13 caused by the excavation of the advanced central shaft 11 may spread out of the area of the large-section tunnel 2 as shown in FIG. Means that the pre-assembly method is to be applied. For this reason, ground improvement is to be performed by existing simple means, for example, mortar filling type fore polling (Fore Poling) using a fiber bolt 14, urethane injection type fore polling, or the like. become. In principle, this ground improvement is cast in the inside area of the prelining concrete 10, but it may be cast out of the area.
[0018]
Next, in the advanced central shaft 11 excavated in advance as described above, the preceding invert concrete 15 is cast behind the lower shaft portion 11a, as shown in FIGS. You do it. Next, in claim 2, by using a time lag of about several tens of days until the main shaft cutting face 2a described below approaches, the work from the advanced central shaft 11 is used. As shown in FIG. 3, the precedent reinforcement processing is performed on the periphery 16a, 16b of the leg ground at the lower left and right sides of the large-section tunnel 2.
[0019]
As the pre-reinforcement process, the reinforcing foot grounds 18a, 18b are formed by mortar injection or urethane injection using the injection pipes 17a, 17b shown in FIG. 3 inserted from the inner wall surface 11b of the advanced central shaft 11. . After this, the same process is performed in any of claims 1 and 2. First, the pre-lining concrete 10 is formed on the upper surface of the preceding inverted concrete 15 with respect to the main shaft 2a. For the above-mentioned arched tunnel excavator 5, the rail 4 to which the traveling is guided is laid.
[0020]
Next, the above-described arched tunnel excavator 5 is operated to form the prelining concrete 10 as described above with reference to FIGS. 5 to 8. Here, referring to FIG. Will be described in detail. In particular, as clearly shown in FIG. 8, the moving frame 19 supporting the arc-shaped see-through groove excavating chain cutter 6 is moved along the arc-shaped guide member 20 by the cutter advance / retreat driving device 21. After the forward movement, the movable boom 22 supporting the arc-shaped guide member 20 moves along the arch-shaped guide frame 7, whereby the chain cutter 6 for excavating the see-through groove moves the movable boom 22 in the longitudinal direction. The arched see-through groove 8 having an arc-shaped cross section whose middle portion is curved so as to protrude toward the outside of the large-section tunnel is excavated.
[0021]
Next, the curable material 9a is filled and cured in the arched see-through groove 8 through the curable material injection pipe 9, whereby the pre-lining concrete 10 which is an arc-shaped support plate having an arc-shaped cross section is obtained. 5 to 7, reference numeral 23 denotes a drive device of the chain cutter 6 for drilling a through-groove, 24 denotes an injection device for moving an injection pipe, and 25 denotes a movable frame 22. A driving device for movement, 20a is an arc-shaped rack of the arc-shaped guide member 20, 7a is an arc-shaped rack of the arch-shaped guide frame 7, 26 is a wheel running on the rail 4, and 27 is a running driving the wheel 26 8, 28, 29, 30, 31a, and 31b in FIG. 8 indicate a sprocket, a digging blade, a link, and a pair of connecting links in the arc-shaped see-through groove excavating chain cutter 6, respectively.
[0022]
Then, again, the step of forming the pre-lining concrete 10 which is the arch-shaped support plate having an arc-shaped cross section by the chain cutter 6 for excavating an arc-shaped see-through groove is repeatedly performed, and the steps are brought close to or joined to each other. Many pre-lining concretes 10 are sequentially constructed in the longitudinal direction.
[0023]
Here, of course, the rail 4 is laid on the lower base 3 in the conventional example, but is installed on the preceding inverted concrete 15 in the present invention. FIG. 9 relates to the above-described chain cutter 6 for excavating the circular see-through groove in relation to the above-mentioned Japanese Patent Publication No. 4-63198. Instead of providing only one of them, a pair of them is provided. A conventional example is shown (JP-A-2-167994).
That is, FIG. 9 proposes a double chain cutter mechanism that enables the formation of the prelining concrete 10 to be performed more efficiently. It is open in the groove cutting direction D in the through-shaped groove 8 and is movable with the double chain cutter in the longitudinal direction of the large-section tunnel 2.
[0024]
Further, in this groove-shaped cover 32, not only are a pair of chain cutters 6a and 6b for digging the see-through groove which can be driven in the environment arranged not only vertically but also vertically in the radial direction of the large-section tunnel 2, and groove cutting is performed. From the front part to the rear part in the direction D, the arrangement is inclined so as to approach the center of the width of the arched see-through groove 8, and only the front parts of these see-through groove excavating chain cutters 6a and 6b are provided. Are exposed from the channel-shaped cover 32, and the other portions are housed and protected in the channel-shaped cover 32.
[0025]
Therefore, if the above-described double chain cutter mechanism is used to cut the arched see-through groove 8 in the main shaft cutting face 2a as described above, the sediment collapsed at the time of the cutting will cause the see-through groove excavating chain cutter. The chain cutters 6a and 6b for excavating the see-through grooves are provided without being inclined without dropping into the return movement portions of the 6a and 6b and applying an excessive load, and as described above. Therefore, when excavating, the groove-shaped cover 32 does not hinder the excavation, so that it is possible to efficiently excavate the arched see-through groove 8.
In FIG. 9, reference numerals 29a and 29b denote excavating blades of the chain cutters 6a and 6b for excavating the see-through groove.
[0026]
Here, in practice, the central bottom of the arched tunnel excavator 5 can be understood from FIG. 7 and, as shown in FIG. It is preferable that the approach space S be formed under the above-mentioned condition. This makes it possible to cope with the face of the advanced central shaft 11 even when the arched tunnel machine 5 is in operation or at rest. In addition, the excavated earth and sand of the face can be carried out without interruption, and materials can be carried in, so that work efficiency can be improved.
[0027]
After the construction of the prelining concrete 10, as shown in FIG. 1 (B), the main pit face 2 a is excavated by a large-section free-section excavator. The height of the main shaft face 2a is considerably smaller than the height of the large-section tunnel 2 because the height of the main shaft face 2a is set between the shaft support and the prelining concrete 10, so that the face is stable. And the amount of excavated soil decreases.
[0028]
In the present invention, rather than resulting in excavating entire cross-section per the above Honko working face 2a, and of being drilled in advance one half portion 2a ₁ which is the right or left, the pre-lining In this state Since the monopod base 10a of the concrete 10 is located on the periphery 16a of the foot ground in claim 1, and is erected on the reinforcing foot ground 18a in claim 2, the prelining concrete 10 Is suppressed, and under this condition, the preceding invert concrete 15 and the monopod base 10a are continuously connected by the one-side invert concrete 15a.
[0029]
Then, per the other side half portion 2a ₂ in Honko working face 2a, performs the drilling, which between the other leg base 10b before preceding similarly invert concrete 15 and the pre-lining concrete 10 After completion, the other side invert concrete 15b, the entire inner peripheral surface of the large-section tunnel 2 to be excavated is covered with the prelining concrete 10, the preceding invert concrete 15, the one-side invert concrete 15a, and the other-side invert concrete 15b. Will be closed early.
[0030]
Here, in the final stage of the excavation cycle for the main shaft face 2a, since the above-mentioned arched tunnel excavator 5 moves forward to form the next prelining concrete 10, the above-mentioned guide shaft support is provided. The steel support 12 can be reused. Since the inner surface of the pre-lining concrete 10 is exposed in this manner, the secondary lining arch concrete 33 is applied thereto as appropriate, as shown in FIG. 1B.
[0031]
【The invention's effect】
Since the present invention can be carried out as described above, according to claim 1, after digging in advance an advanced central shaft and laying a rail on the preceding invert concrete poured into this, Since the pre-lining concrete is constructed in the large section tunnel area by the arched tunnel excavator running on the rail, the self-sufficiency of the main pit face for applying the pre-lining concrete can be secured and the safe work can be guaranteed, The amount of excavated soil at the time of excavation of the arch-shaped main face can be reduced, and the excavation efficiency can be improved.
[0032]
In addition, the excavation is divided into two parts on the left and right sides of the main shaft, and on the stairs after one excavation, each of the above-mentioned preceding invert concrete and prelining concrete leg bases is also connected to one side invert concrete and the other. Since the continuous inverting concrete is used, settlement of the prelining concrete can be prevented early without delay.
[0033]
Furthermore, in claim 2, in addition to the step of claim 1, since the advanced central shaft has been laid after the preceding invert concrete, the pre-reinforcement concrete for the periphery of the foot ground of the pre-lining concrete is performed. In addition, undesired settlement of the prelining concrete can be suppressed with a higher probability.
[Brief description of the drawings]
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (A) is a schematic view of a vertical cross-section of a ground showing a process of forming prelining concrete in a method of excavating a large-section arched tunnel according to the present invention, and FIG. FIG. 3 is a schematic cross-sectional front view of a ground in a state where concrete and other-side invert concrete are cast.
FIG. 2 is a cross-sectional front view of the ground showing an auxiliary receiving method applied to a loosened area in the main shaft face as required in the excavation method according to the present invention.
FIG. 3 is an explanatory cross-sectional view of the ground showing the pre-reinforcement processing performed on the periphery of the foot ground of pre-lining concrete in the above-described excavation method according to claim 2;
FIG. 4 is a flowchart showing a process order of the above excavation method according to claim 2;
FIG. 5 is a schematic vertical sectional side view of a ground showing one mode of use of an arched tunnel excavator used for forming prelining concrete according to the present invention.
FIG. 6 is an explanatory plan view showing the arched tunnel excavator in FIG. 5;
FIG. 7 is a cross-sectional front view showing the arched tunnel machine shown in FIG. 5;
FIG. 8 is a partial perspective view of a chain cutter for drilling a seepage groove in the arched tunnel machine shown in FIG. 5;
FIG. 9 is a partial cross-sectional front view of the arched tunnel machine having a different color from that of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ground 2 Large section tunnel 2a Main pit face 2a ₁ One half 2a _{2 The} other half 4 Rail 5 Arch type tunnel excavator 6 Chain cutter for drilling a through groove 8 Arch through groove 9a Hardening material 10 Prelining concrete 10a Monopod base 10b Other leg base 11 Advanced central shaft 11a Lower base 15 Leading invert concrete 15a One side invert concrete 15b Other side invert concrete 16a Leg base periphery 16b Leg base periphery 18a Reinforcement leg ground 18b Reinforcement foot ground

Claims (2)

At the center of the large section tunnel area to be excavated to the required ground, an advanced central shaft is dug by a desired length, and if necessary, a shaft support or a shaft support for the advanced central shaft is required. After carrying out auxiliary work, placing the leading invert concrete on the lower part of this advanced central shaft, laying a rail on the leading invert concrete, and placing it on the main shaft The arch-shaped tunnel excavator for traveling is guided, and by the operation of this arch-shaped tunnel excavator, the arc-shaped through-groove having an arc-shaped cross-section is excavated by the arc-shaped through-groove excavating chain cutter. The pre-lining concrete, which is an arch-shaped support plate having an arc-shaped cross section, is erected by filling and hardening a curable material, and then the pre-lining concrete and the advanced central conductor are erected. After excavating and removing one half of one side of the arch-shaped pit face between the above, between the preceding invert concrete and the monopod base of the pre-lining concrete, one side invert concrete is connected, and then Excavating and removing the other half of the shaft face of the main shaft, connecting the base of the preceding invert concrete and the other leg base of the prelining concrete with the other side invert concrete, and starting from the erecting of the prelining concrete, The excavation of a large-section arched tunnel characterized by repeating the process of connecting the inverting concrete on the other side and placing the secondary lining arch concrete on the inner surface of the pre-lining concrete in a timely manner. Construction method. At the center of the large section tunnel area to be excavated to the required ground, an advanced central shaft is dug by a desired length, and if necessary, a shaft support or a shaft support for the advanced central shaft is required. After carrying out auxiliary work and placing inverting concrete on the lower part of this advanced central shaft, advance reinforcement processing by injection operation from the advanced central shaft to the periphery of both legs of the large section tunnel area is performed. Then, a rail is laid on the preceding invert concrete, and an arched tunnel excavator for the main tunnel face, which is the large section tunnel area, is guided on the rail, and the operation of the arched tunnel excavator is performed by operating the arched tunnel excavator. By using the chain cutter for excavating the arc-shaped see-through groove, an arch-shaped see-through groove having an arc-shaped cross section is excavated, and a hardening material is filled and hardened into the arch-shaped see-through groove, thereby forming an arch-shaped support plate having an arc-shaped cross section. After a certain prelining concrete is erected on the ground of the reinforcing leg formed by the preceding reinforcing treatment, one side of the arched main shaft face between the prelining concrete and the advanced central shaft is provided. After excavating and removing one half, the preceding invert concrete and the monopod base of the pre-lining concrete are continuously connected by one-side invert concrete, and then the other half of the main shaft is excavated and removed. The other side of the preinverted concrete and the base of the prelining concrete are continuously connected by the other side of the inverting concrete, and the steps from the erecting of the prelining concrete to the connecting of the other side of the inverting concrete are repeated. Timely placing secondary lining arch concrete on the inner surface of lining concrete Excavation method of large cross-section arcuate tunnel, characterized in that it has to be subjected.

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