JPH03212597A - 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 shield excavator that excavates a tunnel while simultaneously excavating the tunnel and performing primary lining.

(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 is: - Excavation and primary lining work are performed alternately in boat fishing, but in recent years, in order to shorten the construction period, there has been a demand for a method that allows excavation and primary lining work to be carried out at the same time. It has become.

Two such means are described, for example, in Japanese Patent Application Laid-open No. 58-213993 and Japanese Patent Application Laid-open No. 58-213994.

The former shield excavator has a shield jack that divides the shield body into two, front and rear, and propels the shield body toward the rear shield, and a slide that slides the front and rear shields against the rear shield between the front silt and the rear shield. It has a structure with a jack, and after the shield jack propels the shield body by one ring of the segment, the slide jack further propels the front and rear shields, and during this time, the shield jack 7 is partially returned. 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 knoll, when the front shield is propelled, the rear knoll slides. 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 allows tunnel excavation and primary lining to be carried out at the same time without disturbing the face, and a shield tunneling machine used for excavation. It is something.

(Means and Effects for Solving the Problems) In order to achieve the above object, the present invention provides a plurality of double-acting cylinders in a sliding ring that is slidable in the front and back direction with respect to a shield body having a cutter head in the front part. Set up a book shield jack,
The front piston rod and rear piston rod that protrude from the front and back of these shield jacks are expanded and contracted to simultaneously perform propulsion by the shield body and primary lining of the excavated tunnel inner wall. There is no need to provide a thrust cylinder and it can be implemented at low cost.

In addition, a sliding ring is provided inside the shield body having a cutter head at the front part so as to be slidable in the front and back direction of the shield body, and a plurality of cylinders each having a cylinder fixed to the sliding ring are arranged in the circumferential direction of this sliding ring. A shield jack is provided, and a front piston rod and a rear piston rod are provided to project forward and backward from a plurality of pistons housed in the cylinder of this shield jack, and the tip of the front piston rod is attached to the shield body side. , and the tip of the rear piston rod is in contact with a segment lining the inner wall of the tunnel, and the front piston rod and the rear piston rod are connected to each other while controlling the hydraulic pressure between the pistons according to the soil pressure of the face and the water pressure. By sequentially expanding and contracting, excavation and primary lining can be performed simultaneously.In addition to being able to excavate without disturbing the face, there is no need to install a complicated sealing device, allowing for safe and reliable excavation and primary lining. Simultaneous construction is 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, which is rotated by a rad motor to a cutter (not shown), is provided at the front part.

The earth and sand excavated by the above-mentioned power feeder nod 2 is removed by the cutter head 2.
After being taken into a chamber 1b provided between the shield body 1a and the partition wall 1a, the shield body 1 is discharged to the rear of the shield body 1 by an unillustrated discharge device.

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

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 rear piston rod 4e is fixed to the rear surface of the partition wall 1a via a ball joint 5, and the tip of the rear piston rod 4e is brought into contact with the end surface of the segment 7 via a pole joint 6.

In the figure, 10 is a segment selector that assembles the segments 7 in a ring shape along the inner wall of the tunnel immediately after the shield body 1 has excavated, and 11 is a segment selector that allows dirt and water to enter between the rear end of the shield body 1 and the outer circumferential surface of the segments 7. This is a tail seal that prevents

Next, the operation will be explained. In FIG. 1, the shield body 1 is propelled while extending the front piston rod 4d using the existing segment 7 as a reaction force.

This shows a state in which the face is being excavated with the cutter head 2, and in this state, each piston 4b is further removed.

When high pressure oil is supplied to the hydraulic chamber 4□ between 4C and 4C, the front piston rod 4d further extends to propel the shield body 1, as shown in FIG.

At this time, as the shield body 1 is propelled, the cylinder 4a retreats relative to the shield body 1, and accordingly, the sliding ring 3 fixed to the cylinder 4a also moves against the shield body l.
It is in a relatively retracted state while sliding on the inner surface of.

Further, since the hydraulic chamber 43 on the side of the rear piston rod 4e is blocked, the rear piston rod 4e does not operate.

Next, when the front piston rod 4d is extended by one pitch by the width of the segment 7, the hydraulic chamber 41 on the side of the front piston rod 4d
, and extracts the hydraulic pressure from the hydraulic chamber 4 on the rear piston rod 4e side.

As a result, the cylinder 4a moves forward together with the sliding ring 3 as shown in FIG.

Further, at this time, high pressure oil is blocked in the hydraulic chamber 42 between each piston 4b, 4c.

Since the shield body 1 is not pushed back against earth pressure or water pressure applied to the shield body 1 from the face side, it is possible to prevent the face from being disturbed and the ground from collapsing.

When the partial cylinder 4a and the sliding ring 3 are advanced to the stroke end, a portion of the rear piston rod 4e is shortened to form a space for one segment, and a segment erector 10 is used to fill this space. 4 Assemble segment 7 as shown in Figure 4.

Of course, at this time, at the same time, the cutter head 2 is rotated to excavate, the hydraulic chamber 41 is opened, and high pressure oil is sent to the hydraulic chamber 4□ to extend and propel the piston rod 4d.

Thereafter, the rear piston rod 4e is shortened one segment at a time, and the rear piston rod 4e is brought into contact with the assembled segment 7 again to assemble the segments 7 one after another in one circumferential direction while receiving the digging reaction force. One ring will be completed and excavation and propulsion will continue.

In addition, in the above operation, the shield jack of the part where the segments are not assembled is the hydraulic chamber 4. By sealing the cylinder 4a and the piston rod 4e, the propulsive reaction force can be supported by the segment 7.

When tightening the shield jack piston rod 4e where some segments are assembled, the hydraulic chamber 4. The hydraulic chamber 41 on the front piston rod 4d side is opened with the hydraulic pressure necessary to receive the digging reaction force applied, and
When a hydraulic pressure slightly larger than the hydraulic pressure in the hydraulic chamber 4□ is applied to the hydraulic chamber 43 on the rear piston rod 4e side to relieve the oil in the hydraulic chamber 42, the front piston rod 4d also increases the thrust while the rear piston rod 4e contracts. Generate and expand.

As a result, even during segment assembly, all the shield jacks can be propelled by generating thrust while supporting the propulsion reaction force of the shield body 1 to the segments 7 via the sliding ring 3.

Once the segment 7 for one ring is assembled on the front side of the existing segment 7 as described above.

The state shown in Fig. 1 is reached again, and the above operation is repeated.
Excavation work using the shield body 1 and assembly work of the segments 7 can be performed simultaneously.

Further, in FIG. 3, the forward movement of the cylinder 4a and the sliding ring 3 can be carried out smoothly and in a short time because the only load factors are the sliding resistance of the sliding ring 3 and the hydraulic line resistance.

(Effects of the Invention) As described in detail above, the present invention includes a plurality of shield jacks each consisting of a double-acting cylinder provided on a sliding ring that can freely slide in the front and back directions with respect to the shield body, and The front piston rod and rear piston rod, which protrude forward and backward, are expanded and contracted to simultaneously perform propulsion by the shield body and primary lining of the inner wall of the excavated tunnel. By maintaining and controlling the hydraulic pressure at a value sufficient for the soil pressure and water pressure of the face, the shield body will not be pushed back by the excavation reaction force and disturb the face, and the cutter head will not be pushed too much against the face.

This may cause other mountains to collapse or turn into cutters.

In addition to being able to eliminate problems such as deformation or damage to the shield's component parts, the shield body has an integral structure and a sliding ring is installed inside the shield body. 3) There is no need to provide a complicated sealing device, and there are no problems such as a damaged sealing device that requires a lot of time and money to repair or replace.

Furthermore, since no thrust cylinder is required, the configuration is simple and can be implemented at low cost.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view;
FIGS. 2 to 4 are process charts. l...Shield body, 2...Cutter head. 3...Sliding ring, 4...Shield jack 4a...Cylinder, 4b, 4c...Piston 4d...Front piston rod. 4e... Rear piston rod. 7...Segment.

Claims (2)

[Claims] (1) A plurality of shield jacks made of double-acting cylinders are provided on a sliding ring that can freely slide in the front and rear directions with respect to the shield body that has a cutter head on the front part, and the front parts of these shield jacks protrude in the front and rear directions. A tunnel excavation method characterized by expanding and contracting a piston rod and a rear piston rod so that propulsion by the shield body and primary lining of the excavated tunnel inner wall are performed simultaneously. (2) Inside the shield body with a cutter head at the front,
A sliding ring is provided so as to be slidable in the front and back direction of the shield body, and a plurality of shield jacks each having a cylinder fixed to the sliding ring are provided in the circumferential direction of the sliding ring, and a plurality of shield jacks are provided in the cylinder of the shield jack. A front piston rod and a rear piston rod are provided to protrude in the longitudinal direction from the plurality of pistons accommodated, and the tip of the front piston rod is attached to the shield body side, and the tip of the rear piston rod is a segment that lines the inner wall of the tunnel. Excavation and primary lining are carried out at the same time by sequentially expanding and contracting the front piston rod and the rear piston rod while controlling the hydraulic pressure between each piston according to the earth pressure and water pressure of the face. A shield excavator characterized by: