JPH0528317B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of the Invention The present invention relates to a tunnel docking method in a mechanized shield.

``Prior art and problems to be solved by the invention'' Generally, when constructing a long tunnel using the shield method, excavation is performed from both sides and a dock is placed in the middle, but in sites where the ground is soft, such as undersea tunnels, There was a problem with the ground collapsing in the Dotsuking section.

In order to solve this problem, conventional methods have been used, such as freezing the ground around the docking part in advance, improving the ground by injecting chemicals, and then excavating from both sides, or installing support hoods that can move forward and backward at the tips of both shield bodies. A known method is to do this, then stick out the mutual support hoods and join them after docking.

However, in the former method, it is inefficient because it is necessary to stop excavation and implement soil improvement methods before docking, and in particular, the freezing method requires a large amount of time and cost to form frozen soil, and the chemical injection method However, there were drawbacks such as the fact that reliable solidification could not be expected.

In addition, in the latter case, if the excavation position is misaligned or the excavation direction is diagonal, problems may occur such as the support hoods on both sides being misaligned or becoming impossible to eject.
There were drawbacks such as the inability to expect safe and reliable dotting.

"Means for Solving the Problems" In order to solve the above-mentioned conventional problems, the present invention has the following features:
Two shield machines excavate from opposite directions, and after the two shield bodies come to a stop close to each other, a large number of cryotubes are installed around one shield body so as to be able to slide in the distal direction. The advanced equipment is moved forward so as to be close to the tip of the shield body, and then the surrounding ground is frozen by sending cooling fluid through each of the freezing tubes, and in this state, the advanced equipment is removed safely. This paper proposes a construction method that allows for penetrating construction at the docking part.

"Embodiment" Below, an embodiment of the present invention shown in the drawings will be described. In two shield machines 1 and 1' that dig in mutual directions from both sides, a predetermined interval is formed on the outer periphery of one of the shield bodies 2. A large number of guide grooves 3 are formed in the front and back direction, and two sets of freezing tubes 4, 4' each having a sharp tip are fitted into each guide groove 3 so as to be slidable along the guide grooves. The freezing tubes 4, 4' are arranged in a positional relationship such that they are located outside the outer periphery of the other shield body 2'.

The freezing tubes 4, 4' are connected to each other so that a cooling fluid such as brine can circulate therebetween.

The shield body 2 facing the rear of the guide groove 3 has a slit 5 in the sliding direction of the freezing tubes 4, 4'.
is provided, and this slit 5 is closed by a cover plate 6 during excavation.

Then, the shield machine 1 with the freezing tubes 4, 4' installed in this way and the normal shield machine 1'
While constructing a shield tunnel, the tunnel is excavated sequentially from both sides, and both shield bodies 2, 2' are brought close to each other at the docking part.

After the shield bodies 2 and 2' have approached each other, the shield machine 1' is stopped, and each cover plate 6 on the inner circumference of one of the shield bodies 2 is removed, and the freezing tubes 4 and 4' exposed from the slit 5 are removed. The reaction member 7 is fixed to the bottom of the
A jack 9 is set between the shield main body 2' and the front end of the shield body 2', and thereby each cryotube 4, 4' is sequentially advanced so that its front portion is located on the outer periphery of the front end of the other shield body 2'.

In this state, the reaction member 7 is removed, and a supply pipe 10 and a discharge pipe 10' for a cooling fluid such as brine (calcium chloride) are connected to each freezing tube 4, 4', and the cooling fluid is pumped and circulated. in this case,
It is reasonable to connect the supply/discharge pipes 10, 10' by screwing the bolt holes of the removed reaction member 7 to the inlet and outlet of the cooling fluid.

By circulating the cooling fluid in each cryotube 4, 4 in this way, both shield bodies 2, 2'
The ground around the area is frozen and strengthened, and this frozen soil 11 is used to retain water.

In this state, remove the bulkheads 12 of both shield bodies 2, 2' and tip equipment such as the rotary cutter 13, and further excavate and remove the remaining earth and sand between the tips of each other to dock both shield tunnels. do.

"Effect of the invention" Two shield machines excavate from opposite directions, and after the shield bodies of both machines come to a close and stop,
A number of cryotubes attached around one shield body so as to be slidable in the distal direction are moved forward so that their front parts are located on the outer periphery of the tip of the other shield body, and then cooling fluid is sent to each cryotube. By flowing, the surrounding ground is frozen, so the surrounding ground is frozen and strengthened to ensure safe earth retention.Afterwards, the tip equipment of both shield machines and the remaining earth and sand between the tips are safely and accurately removed. In addition, since the freezing tube is pre-piped around one of the shield bodies, freezing work can be carried out quickly with both shield bodies close together. Since it is in a frozen state, there is less area to freeze, which makes it possible to reduce construction time and construction costs.

[Brief explanation of the drawing]

Fig. 1 is a front view of the shield main body used in this invention, Fig. 2 is a partially enlarged vertical sectional view of the guide groove,
Figure 3 is a vertical side view of the same, Figure 4 is a bottom view of the same, Figure 5 is a side view of the same.
FIG. 6 is a longitudinal side view showing the state of the shield machine according to the present invention immediately after docking, and FIG. 6 is a longitudinal side view showing the state after docking. 1, 1'... Shield machine, 2, 2'... Shield body, 3... Guide groove, 4, 4'... Freezing tube,
7... Reaction force section, 8... Segment, 9... Jacket, 10... Supply pipe, 10'... Discharge pipe, 11...
...Frozen earth, 12...Bulkhead, 13...Rotating cutter.

Claims (1)

[Claims] 1 Two shield machines excavate from opposite directions, and after their shield bodies come to a halt close to each other, a large number of cryotubes are installed around one shield body so as to be able to slide in the distal direction. The shield machines are moved forward so that they are located at the outer circumference of the tip of the shield body, and then the surrounding ground is frozen by sending cooling fluid through each of the freezing tubes, and in this state, the tip equipment of both shield machines is removed. A tunnel docking method for mechanized shielding.