JP2000248875A - Long end support construction method for tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a long end support construction method using a long end support member wherein while the merit thereof is being maintained, the ground around the support member is surely strengthened so that the safety of the construction can be improved. SOLUTION: Prior to a tunnel boring operation, long end support members 1a-1c each provided with a self-boring bit at its end are successively driven into the vicinity of the profile of a tunnel at proper intervals to strengthen it. As the tunnel boring operation progresses, short injection tubular members 15, 18 are successively driven so as to reach the vicinity of the driven member 1b to inject a hardening filler into the ground around the member 1b to strength it, while the operation is being performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prior art excavation operation, in which a long receiving member made of a long steel pipe or the like is sequentially cast around a section of a tunnel in front of a cutting face to loosen or sink the ground. The present invention relates to a method for receiving long tunnels in tunnels to prevent construction and improve construction safety. More specifically, the present invention relates to a long precedent receiving method for tunnels which improves construction safety while combining an elongate precedent elongate member of, for example, 10 to 20 m and a short injection tubular member of about 2 to 4 m.

[0002]

2. Description of the Related Art Conventionally, as this kind of long precedent receiving method, a large number of long precedent long members made of a long steel pipe or the like are cast around a tunnel cross section, and the cast long precedent long member is used. 2. Description of the Related Art A tunnel excavation method is known in which a hardening filler is injected through an inner hollow portion to solidify the periphery, thereby performing excavation work while reinforcing the ground. As for the method of driving the long receiving member, there is known a method of driving the long member to a predetermined depth while drilling the hole by a drill bit attached to the distal end. In such a case, an appropriate number of tubular members may be added as needed to be used as an elongate member for pre-receiving having a desired length.
Then, when the placing operation of the long member for receiving on the ground is completed, for example, the drilling bit is reduced and taken out together with the rod for drilling through the inner hollow portion of the long member for receiving. Thereafter, a method of injecting a curable filler from the distal end portion to the periphery through the inner hollow portion of the long receiving member is generally adopted. Further, a mouth injection pipe is provided in a gap between the mouth of the elongated member for receiving and the hole wall around the mouth, and a curable filler is injected also from the mouth. That is, the injection of the curable filler into the periphery of the elongated member for receiving is, depending on the geology of the ground, the injection from the distal end portion performed through the inner hollow portion of the elongated member for receiving. Injection from the mouth, which is performed via a mouth injection tube.

[0003]

However, since the long member for receiving is long, for example, 10 to 20 m, even if the filler is injected from both the front end and the mouth,
It is not technically easy to accurately inject the intermediate portion. For this reason, there may be a portion where the reinforcement by the filler is not sufficiently spread in the intermediate portion. Moreover, depending on the geology of the ground, the hole wall formed by drilling of the drill bit may collapse, and it may be difficult to insert the mouth injection pipe into the mouth portion of the long receiving member.
In such a case, the insufficiently injected portion of the filler material further spreads from the middle portion of the long member for pre-receiving to the mouth portion, and there is a serious problem in the ground reinforcement state necessary for ensuring the safety of construction. Will be.

[0004] The present invention has been made in view of the above-described conventional circumstances, and while maintaining the advantages of a long precedent receiving method implemented by using a long precedent elongate member, the present invention is not limited thereto. It is an object of the present invention to provide a method for receiving a long point of a tunnel in which the ground around the receiving long member can be properly strengthened and safety of construction can be improved.

[0005]

According to the present invention, in order to solve the above-mentioned problems, prior to the excavation work of the tunnel, a long receiving member having a self-drilling bit at its tip is sequentially arranged at appropriate intervals around the tunnel cross section. In addition to strengthening the periphery of the tunnel cross-section by these pre-receiving long members, as the excavation work of the tunnel progresses, the vicinity of the perimeter of the pre-installed pre-receiving long members is reached. A technical means of sequentially casting short injection tubular members and performing excavation work while injecting and hardening a hardening filler around the long elongate receiving member through the injection tubular members and reinforcing the same. Adopted. With the adoption of this technical means, according to the present invention, while taking advantage of the fact that the ground can be effectively strengthened over a wide range of the long member for receiving, while excavating work proceeds,
The method of casting the filling material by pouring the injection tubular member into the part requiring reinforcement, so that the curable filler is accurately injected into the necessary part over the entire length of the long receiving member. The construction safety is improved because the periphery of the tunnel section is reinforced appropriately. Further, when the long receiving member is cast around the cross section of the tunnel, a curable filler is injected from the front end portion through the inner hollow portion of the long receiving member, Install a mouth filling pipe around the mouth of the long member, inject the curable filler from the mouth through the mouth filling pipe, and for those parts where the filler does not reach enough even by these injections Then, it is also possible to apply the above-mentioned method of casting a filler by casting an injection tubular member.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention can be widely applied to any construction method using a long receiving member having a self-drilling bit at the tip. As a specific form of the self-drilling bit, various types can be applied, and a type that is attached to the distal end of the long receiving member itself and driven to rotate through the tubular member can be used. Alternatively, it may be of a type that is mounted on the tip of a piercing rod inserted through the inner hollow portion of the long receiving member and is driven to rotate through the rod. In addition, a type for collecting the self-drilling bit or a type for leaving the bit buried may be used. Furthermore, as for the method of injecting the curable filler into the periphery of the long receiving member, a method of injecting all the fillers through the injecting tubular member which is sequentially driven exclusively according to the progress of the excavation work. It may be adopted, as in the embodiments described below, or filling the filler from the distal end portion through the inner hollow portion of the long receiving member, from the mouth portion through the mouth injection pipe. It is also possible to adopt a method in which a filler is injected, and a filler is supplied to a portion where the filler is likely to be insufficient even by the injection to replenish the filler. In addition, regarding the injection of the curable filler performed through the inner hollow portion of the first receiving long member, the curable filler may be injected using the inner hollow portion itself as a flow path, As in the embodiment described later, an injection tube may be inserted into the inner hollow portion and injected through the injection tube. As the curable filler, it is possible to use a cement-based filler or a resin-based resin having good permeability such as urethane. Further, it is also possible to add and use an appropriate number of the long members for pre-receiving as needed. In addition, the specific configuration and placement position of the short casting tubular member to be placed according to the progress of the excavation work, the placement method, and the like are not particularly limited, and the periphery of the long member for receiving first. What is necessary is just a form which can inject | pour a hardening filler.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view illustrating a state in which a long member for pre-receiving is used for the long pre-receiving method for a tunnel according to the present invention. In the figure, reference numeral 1 denotes an elongate receiving member, which in this embodiment is configured to inject a filler from a distal end portion through an inner hollow portion of the elongate receiving member 1 as described later. But it is not necessary. Long member for receiving first
Is constructed so that the entire length can be extended by adding an appropriate number of tubular members using the connecting member 2. An appropriate type of self-drilling bit 3 is screwed into the distal end portion of the long member 1 for receiving of the present embodiment via a male screw formed on the outer peripheral surface of the long member 1 for receiving as shown in the figure. Have been. Further, an injection pipe support member 4 is mounted inside the distal end portion of the long receiving member 1, and one end of the injection pipe 5 for the filler is fitted into a support hole formed in the axial center thereof. Thereby, the self-drilling bit 3 is configured to be supported in a state of being communicated with the passage 6 formed therein. In addition, this injection pipe 5
May be previously set in the inner hollow portion of the long receiving member 1 before the long receiving member 1 is cast on the ground 7 as described above, or may be set after the casting. You may do so. Further, if a tapered portion for guiding the end of the injection pipe 5 to the support hole is formed on the end face of the injection pipe support member 4 as shown in the figure, the setting operation of the injection pipe 5 can be simplified.

[0008] The long member 1 for pre-receiving is connected to the ground 7
In this embodiment, in the present embodiment, a turning force, a hitting force, or the like is applied to the self-drilling bit 3 at the distal end through the long receiving member 1 itself to cut the hole by itself. To the depth of. When the operation of placing the long receiving member 1 on the ground 7 is completed, the operation shifts to the operation of injecting the filler. In the present embodiment, the filling operation is performed through the injection pipe 5 and the passage 6 formed in the self-drilling bit 3, and at the same time, the mouth portion and the hole wall 8 of the long receiving member 1. This is performed via a mouth injection pipe 9 installed in a gap between the opening and the opening. By this injection work, a hardening filler is injected from the front end or the periphery of the self-drilling bit 3 through the passage 6 to the vicinity of the front end of the long receiving member 1. Then, the injected filler penetrates into the gap between the long receiving member 1 and the hole wall 8 and the surrounding ground 7 to be hardened and to strengthen the ground at the periphery. Similarly, the filler injected through the mouth injection pipe 9 is used for the first receiving long member 1.
And hardens by penetrating into the gap between the mouth portion and the hole wall 8 and the surrounding ground 7 to strengthen the ground at the periphery. However, as described above, the long member 1 for pre-receiving is, for example, 10-2.
Since it is as long as 0 m, even if the filler is injected from both the tip and the mouth, it is not technically easy to accurately inject the filler up to the intermediate portion of the long member 1 for receiving. There may be a case where parts are not sufficiently spread.
In addition, depending on the geology of the ground, the hole wall 8 formed by drilling the drill bit 3 is collapsed, and the mouth injection pipe 9 cannot be installed, so that the filling material is insufficiently injected. May extend to the mouth of the long member 1 for pre-receiving.

Next, the features of the present invention will be described. FIG. 2 to FIG. 4 are construction explanatory views schematically showing one cycle of a work cycle in the case where the long receiving member 1 is used. FIG. 2 shows a part of the excavation work.
0 shows the construction state in which the next advance long member 1a was advanced to the vicinity of the tip end of the previously installed long member 1a, and the next long member 1b for advance reception was cast and a hardening filler was injected. It is.
In the figure, 11 is the filler injected previously, 12 is the filler at the tip injected through the inner hollow portion of the long receiving member 1b that has been installed this time, and 13 is the same that has been installed this time. It shows the filler injected through a mouth injection pipe (not shown) installed at the mouth of the long receiving member 1b. The long receiving member 1b cast this time is in a state where both sides are supported by the filler 13 at the mouth and the filler 12 at the tip, but the filler does not reach the middle part. There is a part, and the effect of reinforcing the ground at that part is not sufficient. In addition, the long member 1b for receiving first
Is installed in a state of being inclined such that the front is slightly upward as shown in the figure.

FIG. 3 shows a construction state in which the excavation work has advanced to the intermediate face portion 14. In this case, in the process of proceeding from the construction state of FIG. 2 to the construction state of FIG. 3, as shown in FIG. A short injection tubular member 15 is cast into an intermediate portion or the like of the receiving long member 1b where the filler is insufficient, so as to reach near the periphery thereof,
A construction method is employed in which a filler 16 is injected through the injection tubular member 15 to advance the excavation work while reinforcing the ground. In the drawing, reference numeral 17 denotes a support made of steel or the like.

Further, as the excavation work advances, a short injection tubular member 18 is poured into a portion of the long receiving member 1b where the filler is likely to be insufficient, and the filler 19 is injected. When the reinforcing operation is repeated, the filler 12 injected from the distal end of the elongated member 1b for a long time is eventually formed.
, And the surrounding ground is properly strengthened over the entire length of the first receiving long member 1b. In this way, the excavation work proceeds, and when the face portion 20 advances to the vicinity of the distal end of the long receiving member 1b as shown in FIG. 4, the construction state similar to FIG. 2 is reached. That is, the work cycle according to the present invention is completed. Then, similarly to the above, a new next elongate member for first receiving 1c is cast and the above operation is repeated, whereby the tunnel excavation work is sequentially advanced. In the case where the hole wall 8 is easily collapsed due to the geology of the ground 7, the injection of the filler from the mouth may be omitted. Further, as described above, the injection of the filler material from the distal end portion and the mouth portion of the long member for pre-receiving 1 is omitted, and the filling is performed only through the injection tubular member that is sequentially driven in accordance with the progress of the excavation work. It is also possible to adopt a technique of injecting a material.

[0012]

According to the method of the present invention, it is possible to effectively strengthen the ground over a wide area of the long receiving method by using the long member for receiving. Meanwhile, according to the progress of the excavation work, a method of casting a short injection tubular member and injecting a filler material is employed, so that a necessary portion over the entire length of the long member for pre-receiving is hardened. Filling material can be injected accurately, and the periphery of the tunnel cross section is reliably reinforced, so construction safety is greatly improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal cross-sectional view illustrating a driving state of a long member for pre-receiving used in a long pre-receiving method for a tunnel according to the present invention.

FIG. 2 is a construction explanatory view exemplifying an outline of a work cycle when the long receiving member is used.

FIG. 3 is a construction explanatory view exemplifying the outline of the work cycle.

FIG. 4 is a construction explanatory view exemplifying the outline of the work cycle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Long member for receiving, 2 ... Connecting member, 3 ... Bit for self-drilling, 4 ... Injection tube support member, 5 ... Injection tube, 6 ... Passage, 7
... ground pile, 8 ... hole wall, 9 ... mouth injection pipe, 10 ... face, 1
1 to 13: Filler, 14: Face, 15: Injection tubular member, 16: Filler, 17: Shoring, 18: Injection tubular member, 19: Filler, 20: Face

Claims (3)

[Claims] 1. Prior to a tunnel excavating operation, a long receiving member having a self-drilling bit at its tip is sequentially driven around the cross section of the tunnel at an appropriate interval, and the tunnel cross section is formed by the long receiving member. Along with the progress of the excavation work of the tunnel, a short injection tubular member is sequentially cast to reach near the periphery of the previously installed long receiving member, and A long tunnel receiving method for a tunnel, wherein a digging operation is performed while a hardening filler is injected into the periphery of the elongated member for receiving via a tubular member to reinforce the filler. 2. The method according to claim 1, wherein when the long receiving member is cast around a tunnel cross section, a hardening filler is injected from a front end portion through an inner hollow portion of the long receiving member. 2. The method of claim 1, wherein the tunnel is long. 3. When the long member for reception is cast around the cross section of the tunnel, a mouth injection pipe is installed around the mouth of the long member for reception, and the mouth is inserted through the mouth injection pipe. 3. The method according to claim 1, wherein a curable filler is injected from the portion.