JPH03212596A - Tunnel excavation method and shield excavation machine used for excavation - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tunnel excavation method for excavating a tunnel while excavating the tunnel and performing primary lining at the same time, and a shield excavator used for the excavation.

(Conventional technology) As a conventional tunnel excavation method for excavating a tunnel, the shield method in which the tunnel is excavated using a shield excavator is generally adopted, and the tunnel is excavated while the inner wall of the tunnel immediately after being excavated by the shield excavator is initially lined with segments. The shield construction method used to do this is: - In boat fishing, excavation and segment assembly work are performed alternately, but in recent years, in order to shorten the construction period, there has been a need for a method that allows excavation and primary lining to be carried out at the same time. It has become.

As this means, there are two methods described, for example, in Japanese Patent Laid-Open No. 58-213993 and Japanese Patent Laid-Open No. 58-213994.

The former shield excavator has a shield jack that divides the shield body into two, front and rear, propels the shield body towards the rear shield, and a slide between the front and rear shields that slides the front and rear shields against the rear shield. It has a structure with a jack, and after the shield jack propels the shield body one ring of the segment, the front shield is further propelled by the slide jack, and the shield jack is partially returned during this time. A new segment is assembled in the space between the existing segment and the shield jack.
Since tunnel excavation and primary lining can be carried out at the same time, it has the effect of greatly improving excavation efficiency.

In addition, the latter type of shield tunneling machine has an annular sliding member installed inside the shield body, which has an integral structure, and a reaction force receiving jack on the sliding member, and a shield between the front part of the shield body and the sliding member. It has a structure with a jack, and the first reaction force receiving jack and the shield jack are extended alternately so that tunnel excavation and primary lining can be carried out at the same time.
Similar to the above embodiment, this has the effect of significantly shortening the construction period.

(Problem to be solved by the invention) However, in the former case where the shield main body is divided into two parts and the front shield is made to slide against the rear shield, when the front shield is propelled, the rear shield does not slide easily. Since the surface directly comes into contact with earth and water, it is necessary to provide a seal that is resistant to earth and sand abrasion and water pressure at the sliding fitting part to prevent sand and water from entering the sliding part. However, the seal structure is complicated, and if the seal is damaged, it requires a lot of time and money to repair or replace it.

In addition, in the latter case where an annular sliding member is provided inside the shield body, it is necessary to extend the shield jack after assembling one ring of segments, and then operate both jacks synchronously when shortening the reaction force receiving jack. However, because this synchronized operation is difficult, it can disturb the face, which causes the ground to collapse.

This problem also occurred with the former shield excavator, which had the main body of the shield divided into two.

This invention was made with the aim of improving the above-mentioned conventional problems, and aims to provide a tunnel excavation method that can simultaneously perform tunnel excavation and primary lining without disturbing the face, and a shield tunneling machine used for the excavation. It is.

(Means and Effects for Solving the Problems) In order to achieve the above object, the present invention has a shield body having a cutter head at the front part, which receives a propulsive reaction force through two sets of sliding rings and a shield jack. Then, the shield jack is extended to support the propulsion reaction force acting on the shield body, and then the thrust cylinder is shortened and one sliding ring is advanced to move the shield 9th. When the other sliding ring is moved forward together with the jack cylinder to receive the propulsion reaction force acting on the thrust cylinder, the shield main body is propelled by the thrust cylinder again, and the rear piston rod of the shield jack is gradually shortened. By assembling the segments into a ring shape, tunnel excavation and primary lining can be carried out at the same time.

In addition, two sets of sliding rings are provided inside the shield body having a canter head at the front so as to be movable in the front and back direction of the shield body, and one of the sliding rings is provided with a shield jack consisting of a double-acting cylinder. The tips of the front piston rod and the rear piston rod that protrude forward and backward of the shield jack can be brought into contact with the shield body and the segments, respectively, and
A thrust cylinder is provided between the other sliding ring and the shield body, and the two sets of sliding rings and shield jacks carry the thrust reaction force when the shield body is propelled by the thrust cylinder. Excavation and primary lining can be carried out simultaneously by sequentially expanding and contracting the thrust cylinder.This allows tunnel excavation without disturbing the face, and also eliminates the need for complicated sealing devices, making it safe and reliable. Simultaneous construction of excavation and primary lining becomes possible.

(Example) An embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a shield body having an integral structure, and a cutter head 2 rotated by a counterhead motor (not shown) is provided at the front part.

The earth and sand excavated by the hood 2 to the above cutter is transferred to the cutter head 2.
After being taken into a chamber lb provided between the shield body 1a and the partition wall 1a, the earth is taken out to the rear of the shield body 1 by an unillustrated earth removal device.

3 in the figure is a sliding ring provided inside the shield body 1, which is movable in the front-rear direction of the shield body 1 while slidingly contacting the inner surface of the shield body 1. A plurality of shield jacks 4 are provided at intervals.

The shield jack 4 is composed of a double-acting cylinder in which a plurality of pistons 4b and 4c are housed in a single cylinder 4a, and the center portion of the cylinder 4a is fixed to the sliding ring 3 by means such as welding. A front piston rod 4d projects forward from one piston 4b, and a rear piston rod 4e projects rearward from the other piston 4C.

Among the above piston rods 4d and 4e, the front piston rod 4d
The tip of the piston rod 4e can come into contact with the rear surface of the bulkhead 1a via the pole joint 5.
The tip of the segment 7 can come into contact with the end surface of the segment 7 via the ball joint 6.

On the other hand, a guide cylinder 1c is provided inside the shield main body 1, and another sliding ring 8 is slidably inserted into the outer circumference of the guide cylinder 1c.

The base end of a thrust cylinder 9 is pivotally attached to the sliding ring 8, and the tip of a piston rod 9a that projects forward from the thrust cylinder 9 is pivotally attached to the rear surface of the partition wall 1a.

The rear end of the guide tube ICO is attached to the shield body 1 side by a support frame 1d, and the support frame 1d has a segment erector for assembling the segments 7 in a ring shape along the inner wall of the tunnel immediately after the shield body 1 has excavated. 10 is installed.

In the figure, reference numeral 11 indicates a tail seal that prevents dirt and water from entering between the rear end of the shield body 1 and the outer peripheral surface of the segment 7.

Next, the tunnel excavation method and the operation of the shield excavator will be explained.

FIG. 1 shows a state in which the front and rear piston rods 4d and 4e are minimized, the rear piston rod 4e is in contact with the segment 7 that is being assembled, and the thrust cylinder 9 is extended to be propelled by the shield body 1. show.

At this time, the propulsive reaction force acting on the thrust cylinder 9 is transmitted by the sliding ring 8 to the shield jack 4 via the sliding ring 3, and is supported by the shield jack 4 using the segment 7 as a support.

Also, the front piston rod 4d side hydraulic chamber 4I and the rear piston rod 4e side hydraulic chamber 4 of the shield jack 4. Hydraulic pressure sufficient to counter the propulsive force of the thrust cylinder 9 is blocked in each of the cylinders.

Next, as shown in FIG. 2, when the thrust cylinder 9 is extended by one pitch by the width of the segment 7.

The assembly of one ring of segment 7 is also completed.

From this state, the hydraulic chamber 4 between each piston 4b, 4c. Hydraulic pressure is supplied to the hydraulic chamber 4 on the front piston rod 4d side.
When the hydraulic pressure of 1 is removed, the front piston rod 4d extends as shown in FIG. 3, and the ball joint 5 provided at the tip of the front piston rod 4d comes into contact with the partition wall 1a.

As a result, the shield body 1 is affected by the earth pressure and water pressure on the face side.
is supported by the shield jack 4 so that it is not pushed back. (See FIG. 3) Next, in this state, when the thrust cylinder 9 is shortened, the sliding ring 8 is advanced while slidingly contacting the outer peripheral surface of the guide cylinder IC, as shown in FIG.

At this time, since no reaction force is acting on the thrust cylinder 9, the sliding ring 8 can be smoothly advanced, and at the same time, the pressure in the hydraulic chamber 4□ of the shield jack 4 can be transferred from the face side to the shield body 1. By controlling according to the earth pressure and water pressure applied to the shield body l, it is possible to maintain the shield body l in a stable state.

After the thrust cylinder 9 is shortened by the above process, hydraulic pressure is supplied to the hydraulic chamber 4I on the front piston rod 4d side, and the rear piston rod 4. Remove the hydraulic pressure from the side.

As a result, as shown in FIG. 5, the cylinder 4a of the shield jack 4 is moved forward together with the sliding ring 3, and the sliding ring 3 is brought into contact with the sliding ring 8 on the thrust cylinder 9 side.

When the sliding ring 3 comes into contact with the sliding ring 8 and can support the propulsive reaction force acting on the thrust cylinder 9, the thrust cylinder 9 is extended again to propel the shield body 1 and the canter head 2 At the same time as the excavation, as shown in FIG. 6, a part of the rear piston rod 4e is shortened to form a space for one segment, and the segment erector 10 is used to assemble the segment 7 in this space.

Thereafter, the rear piston rod 4e is shortened one segment at a time, and the remaining segments 7 are assembled one after another, and the rear piston rod 4e is brought into contact with the segment 7 that has been erected again to bear a reaction force.

and segment 7 for one ring along the tunnel inner wall.
When the assembly of the shield main body 1 is completed, the state shown in FIG. 1 is reached again, and by repeating the above operations, the propulsion by the shield main body 1 and the assembly work of the segments 7 can be carried out at the same time.

Also, the operations in the steps shown in FIGS. 3 to 5 are as follows.

Since the only load factors are the extremely small sliding resistance of the sliding ring 3.8 and the hydraulic line resistance, this can be done smoothly in an extremely short period of time.

(Effects of the Invention) As described in detail above, the present invention allows the shield body to be propelled while simultaneously lining the inner wall of the tunnel excavated by the shield body with segments.
Tunnel excavation can be done quickly and efficiently.

In addition, a 2&l sliding ring that is slidable in the front and rear directions is provided inside the shield body, and a shield jack consisting of a double-acting cylinder is installed on one sliding ring, and a thrust cylinder is installed between the other sliding ring and the shield body. The front and rear piston rods and thrust cylinders of these shield jacks are expanded and contracted sequentially, and the 2M sliding ring carries the propulsive reaction force of the shield body, so the shield body is moved by earth pressure and water pressure from the face. is never pushed back.

This makes it possible to eliminate problems such as the face being disturbed and causing the ground to collapse.

By controlling the hydraulic pressure between the multiple pistons installed in the shield jack according to the earth pressure and water pressure at the face, the cutter head will not press too much against the face, causing deformation and damage to the cutter head components. Problems such as this can be prevented.

What's more, the shield body has a one-piece structure, so the sliding parts are not exposed to the outside. 3! It is not necessary to provide a sealing device with a complicated structure, and it is also possible to eliminate problems such as long-term interruption of work due to damage to the seal.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, with FIG. 1 being a sectional view and FIGS. 2 to 6 being process diagrams. 1... Shield body, 2... Cutter head. 3.8...Sliding ring 4...Shield jack, 7...Segment 9...
・Thrust cylinder.

Claims (2)

[Claims] (1) The shield body with a cutter head on the front is propelled by a thrust cylinder while receiving a thrust reaction force through two sets of sliding rings and a shield jack, and then the shield jack is extended and the shield body is attached to the shield body by the shield jack. The thrust cylinder is shortened to advance one sliding ring while supporting the acting propulsive reaction force, and then the other sliding ring is advanced together with the shield jack cylinder to receive the propulsive reaction force acting on the thrust cylinder. This tunnel excavation method is characterized by assembling the segments into a ring shape by sequentially shortening the rear piston rod of the shield jack while propelling the shield body again using the thrust cylinder. (2) 2 inside the shield body with cutter head at the front.
A set of sliding rings is provided so as to be movable in the front and back direction of the shield body, and one of the sliding rings is provided with a shield jack consisting of a plurality of cylinders, and a front piston rod and a rear piston rod that protrude back and forth of the shield jack are installed. The tip of the ring can be brought into contact with the shield body and the segment, respectively, and a thrust cylinder is provided between the other sliding ring and the shield body to reduce the propulsive reaction force when the shield body is propelled by the thrust cylinder. A shield excavator characterized by carrying out excavation and primary lining at the same time by sequentially expanding and contracting a shield jack and a thrust cylinder while being supported by a set of sliding rings and a shield jack.