JPH0312633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shield tunnel construction method that does not require a starting shaft.

``Prior Art'' Conventionally, in order to construct a shield tunnel from a predetermined location underground to another predetermined location, a starting shaft is required to transport the shield machine to the underground excavation starting location.

That is, in the conventional example shown in FIG. 1, 2 is a starting shaft for transporting the shield machine 1 to the underground excavation starting place P, 3 is a retaining shaft for the starting shaft 2, 4 is a raised shaft, and 5 is a strut. , the shield machine 1 is located in the starting shaft 2
It is assembled on a starting platform 6 provided at the bottom of the tunnel, and excavates the planned tunnel excavation location T.

``Problems to be Solved by the Invention'' However, in the conventional example that requires this starting shaft 2, the construction period and cost for constructing the starting shaft 2 increase, and when the starting shaft 2 is constructed, noise and noise are generated. This has the disadvantage that it may cause pollution such as vibration.

For example, if the outer diameter of the shield machine 1 is 3 m, the total length of the shield machine 1 is about 5 m.
Behind the shield machine 1, there is also an inlet/outlet for materials, workers, excavated soil, etc. (provided at the top of the segment rings S, S, S, not shown) and the shield machine 1. In addition, a space for installing the reaction force receiver 20' is required on the side of the shield machine 1 for work such as assembly of the shield machine 1, and the starting shaft 2 has a wide area of 100 m ² or more. There is a limit to the required reduction in construction period and construction cost.

Furthermore, it is of course possible to construct the starting shaft 2 without noise and vibration, but if a continuous underground wall is used for the earth retaining 3, which is conventionally a common noiseless and vibrationless construction method, the construction period will be increased. , which will lead to an increase in construction costs.

Furthermore, it is known that the above-mentioned conventional method is accompanied by a particularly large risk at the beginning of tunnel excavation. The initial launch of the shield machine 1 from the starting shaft 2 until it penetrates the ground by penetrating the earthworks 3 is called Kagami-kiri. The ground deep underground with high pressure and water pressure,
This is due to the fact that the outer circumferential side of the shield machine 1 is adjacent to atmospheric pressure with only a small area being able to be sealed.To prevent this danger, a large amount of water is poured into the starting ground 8 near the tunnel excavation starting point P from the bottom of the starting shaft 2. Supplementary methods such as injecting soil improvement agents will become necessary.

``Purpose'' The present invention was developed in view of the above-mentioned drawbacks, and by omitting the starting shaft and excavating directly from the ground, it reduces the construction period and cost required for constructing the starting shaft, and also eliminates the dangers of Kagami-kiri. The purpose is to avoid this and reduce construction costs.

``Means for Solving the Problems'' In accordance with the above-mentioned object, the structure of the present invention, which is summarized in the above-mentioned claims, is to solve the above-mentioned problems. and a reaction force receiver 20 having an entrance/exit 21 with a smaller diameter than the inner diameter of the shield machine 1 in the center are installed on the ground, and the shield machine 1 starts excavating downward and excavates inside the excavation part to the rear end side. The above reaction force receiver 20
The tunnel is lined with a lining ring segment S1 connected to the edge of the entrance/exit 21, and as the excavation progresses, the lining is sequentially connected with the lining ring segment S2, S3, S4, etc. on the ground side. ,
An approach tunnel T2 is constructed while changing the direction of excavation to the underground tunnel excavation starting location P, and then the shield machine 1 is used to excavate the planned tunnel excavation location T in the usual manner to form the above-mentioned approach tunnel T2. This technical means is characterized in that a continuous tunnel T1 is constructed.

``Operation'' Therefore, the shield tunnel construction method of the present invention that does not require a starting shaft has a shield machine 1 in an inverted state with the cutter facing downward, and an entrance/exit 21 in the center that is smaller in diameter than the inner diameter of the shield machine 1. Since the reaction force receiver 20 is installed on the ground, this shield machine 1 is maintained in a stable state by pressing the built-in shield jack (not shown) against the edge of the entrance/exit 21 of the reaction force receiver 20. Expansion of the shield jack provides a propulsive force for the shield jack 1, and the entrance/exit 21 functions to allow workers and materials to enter and exit.

In addition, the method of the present invention has the effect of being able to carry the shield machine 1 to the underground excavation starting place without building a shaft, but since the shield machine 1 starts excavation directly from the ground, ,
The excavation work is not a discontinuous work of excavating a shaft, carrying in a shield machine 1, and starting excavation by the shield machine 1 as in the past, but can be performed by a series of continuous works by a series of shield machines 1, and the most notable effects are: When excavating deep underground where water pressure is high, the lining with segment rings has already been continued and the contact area between the outer circumference of the existing segment ring and the inner peripheral surface of the tail of the shielding machine 1 is sufficiently secured. Because of this, the sealing can be done satisfactorily using conventional methods, and the dangers associated with conventional mirror splitting are of course avoided, and the risk of landslides, etc. can be avoided in advance.

"Embodiments" Next, embodiments of the present invention will be described below with reference to the accompanying drawings.

First, in the method of the present invention, a shielding machine 1 in an inverted state with a cutter facing downward, and a reaction receiver 20 having an entrance/exit 21 having a smaller diameter than the inner diameter of the shielding machine 1 in the center are installed on the ground.

In the illustrated embodiment, the starting platform 10 is constructed on the ground prior to installing the reaction force receiver 20.

In the illustrated example, this launching pad 10 is formed by pouring reinforced concrete, and as most clearly shown in FIG. The area is filled with gravel or the like and compacted sufficiently to support the weight of the shield machine 1. Depending on the construction method adopted, a rubber gasket 12 is attached around the starting port 11 if the muddy water shield construction method is used. Also,
This starting platform 10 is fixed by earth anchors 13, 13, 13, . . . unless it has an extremely large weight, or is fixed by being integrated with other existing structures. Note that, different from the illustrated example, the starting port 11 may not be provided and the cutter of the shield machine 1 may also excavate the starting platform 10 during the initial excavation. It goes without saying that it should be made of a material that can be excavated with a cutter.

The reason for constructing this starting platform 10 is that it is assumed that the shield machine 1 cannot stand up on its own due to poor ground when it is to be inverted, and it is also connected to the reaction force receiver 20 to fix the reaction force receiver 20. If the ground is sufficiently strong, or if you dig a hole to insert this shield machine 1 and make it stand on its own as described later,
It goes without saying that the reaction force receiver 20 may be omitted if it is separately fixed on the ground.

Further, the shield machine 1 may be a conventionally known one, but the operator's cab or driver's seat (not shown) provided in the shield machine 1 may adjust the angle with respect to the central axis of the shield machine 1 by, for example, the action of gravity. The shield machine 1 is changeable so that even if the shield machine 1 is tilted or horizontal, the driver does not have to lie face down, and the shield machine 1 is provided within the shield machine 1. It is desirable that the operating equipment (also not shown) be moved at a different angle together with the driver's cab or driver's seat so that the shield machine 1 can be operated in a comfortable posture.

To invert the shield machine 1 on the ground, assemble the shield machine 1 in sequence from the cutter side at a predetermined position on the ground, or invert the shield machine 1 assembled near that location or in a factory at a predetermined position. That's fine. However, the cutter side of the shield machine 1 does not necessarily have to be in contact with the top surface of the starting platform 10; instead, a hole into which the shield machine 1 is inserted is provided at a certain depth in advance on the ground surface. The shield machine 1 may be inserted into the hole, or the hole may be made to substantially match the overall length of the shield machine 1, so that the shield machine is inserted into the ground from the beginning. Further, the shield machine 1 may be inverted before the starting platform 10 is fixed, and then the starting platform 10 may be fixed. Further, the above-mentioned shielding machine 1 does not necessarily have to be inverted vertically, and may be installed obliquely.

Furthermore, as most clearly shown in FIG. It is provided with an entrance/exit 21 (of the inner diameter) and is placed on the inverted shield machine 1. In the illustrated example, this reaction force receiver 20 is connected to the starting platform 10 and the steel wires 15, 15, 15.
... etc., so that the shield jack (not shown) of the shield machine 1 acts on the circumference of the entrance/exit 21 of the reaction force receiver 20 to obtain the thrust of the shield machine 1, or the steel wire 15, 15, 15... are inserted through the insertion holes 15a, 15a, 15a... of the reaction force receiver 20 and arranged on the reaction force receiver 20.
The thrust of the shield machine 1 may be obtained by pulling the steel wires 15, 15, 15, etc. at 7 and pushing down the reaction force receiver 20. Note that the reaction force receiver 20 is not limited to the illustrated example shape, and may be constructed of H steel or the like in an appropriate shape, or may be constructed integrally with the starting platform 10. In the case where it is buried in the ground and inverted, a starting platform 10 and a reaction force receiver 20 may be integrally constructed as shown in FIG. 6. In addition, in FIGS. 3 and 4, 13a is the head of the earth anchor 13,
Reference numeral 15b indicates a hole through which the steel wire 15 is inserted.

Then, the shielding machine 1 starts to excavate downward, and the inside of the excavated portion is lined at the rear end side of the excavation with a lining ring segment S1 connected to the edge of the entrance/exit 21 of the reaction force receiver 20, Furthermore, as the excavation progresses, the lining is sequentially lined with lining ring segments S2, S3, S4, etc. that connect with the lining ring segments on the ground side, and the approach tunnel T2 is continued while changing the excavation direction until reaching the underground tunnel excavation starting location P. Build.
This process will be explained in more detail with reference to FIGS. 5 to 8.

First, as described above, the shield machine 1 is placed upside down on the ground as shown in FIG. Then, the shield machine 1 starts digging vertically downward. Until the state shown in FIG. 6 where all of the shield machine 1 goes underground, the thrust of the shield machine 1 is obtained by the jacks 17, 17, 17... or the shield jack, but when using this shield jack, When the shield machine 1 descends a certain distance, the shield jack is returned and the fixed position of the reaction force receiver 20 is lowered by that amount repeatedly.

After excavating to the point shown in FIG. 6, the reaction force receiver 20 is fixed onto the starting platform 10 using a fixture 18 or an appropriate means such as welding.

Next, the shield machine 1 further excavates, but during this excavation, first, the edge of the entrance/exit 21 of the reaction force receiver 20 is used as a reaction force receiver of the shield jack of the shield machine 1. Then, when the reaction force receiver 20 is dug from the lower surface of the reaction force receiver 20 by the length of the segment ring, the shield jack is retracted and the rear end side (upper end side) of the shield jack is retracted and dug into the space. The lining is carried out by the lining ring segment S1 which is thus supported.

Then, as the excavation progresses, the tunnel is lined with lining ring segments S2, S3, S4, etc. that are connected to the lining ring segments on the ground side, and the approach tunnel is continued while changing the excavation direction until reaching the underground tunnel excavation starting point P. This is to build T2.

The above lining ring segments S1, S2, S3...
is assembled within the tail of the shield machine 1 and has a smaller diameter than the diameter excavated by the shield machine 1.
During excavation, the shield jack pushes the bottom ends of the lining ring segments S1, S2, S3, etc., but when inserting a new lining ring segment, the shield jack pushes the bottom ends of the lining ring segments S1, S2, S3, etc. Therefore, the uppermost lining ring segment S1 is fixed to the starting platform 10 or reaction force receiver 20, etc., and the following lining ring segments S2, S3, S
4... are sequentially connected to the upper ones so that the lining ring segments S1, S2, S3... are suspended.

Then, this excavation is carried out vertically or diagonally downward, and until reaching the tunnel excavation starting point P,
Attitude control is performed to maintain the angle of the shield machine 1 at a predetermined level. This posture control of the shield machine 1 is performed by making the shield machine 1 curve while excavating underground, and attaching the lining ring segment S1,
Tapered ones may be used as S2, S3, . . . .

In addition, lining ring segments S1, S2, S3
When the number of installations of... increases, backfill injection Q can be made on the back surface of the lining ring segments S1, S2, S3..., so the starting platform 10 and the reaction force receiver 20 become unnecessary.

Next, in the method of the present invention, the shield machine 1 is used to excavate the planned tunnel excavation site T in a conventional manner to create a tunnel T1 that is continuous with the above-mentioned entry tunnel T2.
Build. After tunnel excavation is carried out by the above method to the tunnel excavation start point P, the reaction force of the shield machine 1 is applied to the already assembled lining ring segments S1 and S.
2, S3... is sufficient, and it is possible to excavate in exactly the same way as the conventional construction method.

In the method of the present invention, the excavated earth and sand can be carried out using a mud drain pipe if the mud shield method is used, or by a wind pipe if it is not a mud water shield method, both of which are common transport methods. Therefore, it is not shown. Furthermore, it is of course possible to carry out the earth and sand using a cart 34, which will be described later. For people to enter and exit, it is preferable to attach rails 30 to the lining ring segments S1, S2, S3, . . . and use a climber cart 31 that runs along the rails 30 as a guide. This climber cart 31 has a person gauge 32 that always faces vertically due to the effect of the center of gravity. In addition, when carrying in materials, lining ring segments S1, S2,
A rail 33 is installed on the opposite side of the rail 30 of S3...
A trolley 3 is attached to the rail 33 and runs on the rail 33 as a guide.
4 should be prepared separately. Cart 34 for this material
A net 35 is attached to prevent falls, and
In the unlikely event that materials fall, it is desirable to install a net at the tail section of the shield machine 1 and behind it to catch the falling objects. Furthermore, surveying during construction can be performed by refracting laser light with a deflector or by using a gyroscope, and these are also common surveying methods.

The example in FIG. 9 is an example in which the shield machine 1 is launched diagonally from the ground, and a stand 40 for holding the shield machine 1 obliquely is provided on the ground, and a reaction force corresponding to the reaction force receiver 20 integrally protrudes from the stand 40. A force receiver 41 is provided, and the shield machine 1 pushes this reaction force receiver 41 with a shield jack to start digging diagonally underground. This diagonal start has the advantage that it does not require a sharp curve to position the shield machine 1 to reach the planned tunnel excavation location T compared to the above-mentioned vertical excavation, and is particularly effective for tunnel excavation shallower than ground level. be.

"Effects of the Invention" The shield tunnel construction method of the present invention that does not require a starting shaft is as described above, and constructs a vertical tunnel lined with lining ring segments S1, S2, S3, etc. from the ground. Start shaft 2
Since this can be omitted, the construction period and cost can be significantly reduced, and there is no pollution caused by the construction of the starting shaft 2.

In addition, the method of the present invention has a noteworthy effect that the mirror cutting work can be omitted and is superior to the conventional method in terms of safety.

Furthermore, the method of the present invention is advantageous in terms of safety, economy, and construction time because the assembly work of the shield machine 1, which was conventionally carried out in the starting shaft 2, is carried out in a wide space above ground. be.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the starting shaft of the conventional method, Fig. 2 is a front view of the shield tunnel construction method of the present invention at the start of excavation, which does not require a starting shaft, and Fig. 3 is a starting platform used in the method of the present invention. 4 is a front view of the reaction force receiver also used in the method of the present invention, FIGS. 5 to 7 are front views for explaining the initial excavation process of the method of the present invention, and FIG. 8 is a front view of the reaction force receiver used in the method of the present invention. A sectional view of a tunnel excavated by the method of the invention, and FIG. 9 is a front view of another embodiment of the method of the invention. 1 - Shield machine, 10 - Starting platform, 20 - Reaction force receiver, 13 - Earth anchor, 15 - Steel wire, P - Tunnel excavation start location, T - Tunnel excavation planned location,
S1, S2, S3 ~ Lining ring segment.

Claims (1)

[Scope of Claims] 1. A shield machine 1 in an inverted state with the cutter facing downward, and a reaction force receiver 20 having an entrance/exit 21 with a smaller diameter than the inner diameter of the shield machine 1 in the center are installed on the ground, The machine 1 starts digging downward, and the rear end of the excavated part is moved to the reaction receiver 20.
The tunnel is lined with a lining ring segment S1 connected to the edge of the entrance/exit 21, and as the excavation progresses, the lining is sequentially connected with the lining ring segment S2, S3, S4, etc. on the ground side. ,
An approach tunnel T2 is constructed while changing the direction of excavation until reaching the underground tunnel excavation start location P, and then the shield machine 1 is used to excavate the planned tunnel excavation location T in the usual manner to form the above-mentioned approach tunnel T2. A shield tunnel construction method that does not require a starting shaft, characterized in that a continuous tunnel T1 is constructed.