JPH07116907B2 - Shield tunnel joining method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a shield tunnel joining method for joining a tunnel in the ground using two shield machines.

<Prior art> Various construction techniques have been proposed for constructing a shield tunnel up to near the joint schedule while excavating with two shield machines set facing each other, and joining both shield tunnels in the ground.

By the way, when adopting this type of joining method, it is important to take measures to stabilize the ground at the shield tunnel joining point.

As a conventional countermeasure work, a chemical injection method and a freezing method are known.

<Problems to be Solved by the Invention> The conventional tunnel junction technology described above has the following problems.

<a> In the chemical liquid injection step, since an expensive chemical liquid is used, the cost is high and the reliability is low in terms of the waterproof effect.

<B> In the case of the freezing method, while it is easy to secure the waterproof effect,
It is difficult to secure sufficient strength.

Therefore, in order to secure sufficient strength, it is necessary to freeze deeply into the deep ground, and the problem of high cost still remains.

<C> The conventional freezing method requires a preceding boring process before installing a long freezing pipe from the rear part of the shield machine to the planned freezing point.

However, various equipments installed in the rear part of the shield machine become an obstacle, and it is difficult to perform the preceding boring work and freeze pipe installation work.

Therefore, it takes a long time to complete the freeze tube installation work, and the construction period tends to be prolonged.

<D> In order to perform preceding boring under high water pressure, an auxiliary construction method and special water stop equipment are separately required to prevent water from entering the shield machine.

<Object of the Present Invention> The present invention has been made to solve the above problems, and an object thereof is to provide the following method for joining shield tunnels.

(1) A method for joining shield tunnels that can significantly reduce construction time and construction costs.

(2) A method of joining shield tunnels that can significantly reduce the amount of frozen soil and also the amount of subsidence of frozen soil.

(3) A method of joining shield tunnels that can create a high-strength, highly water-blocking wall of the ground to be joined.

(4) A method of joining shield tunnels that enables freezing in parallel with the dismantling work of the shield machine.

<Means for Solving Problems> That is, the present invention is a shield tunnel joining method for joining a tunnel constructed using two shield machines in the ground, and a freezing pipe is provided in a hood portion and a cutter portion. Using two shield machines, excavate both shield machines toward the tunnel junction point, agitate the ground at the tunnel junction point to a diameter larger than the cross section of the shield machine, but abut both shield machines, and excavate to the aforementioned large diameter. While solidifying the ground between the tunnel junction point and the cutter parts of both shield machines with solidifying material,
Freezing the surrounding rocks in a wider area than the solidification area by the solidification material at the tunnel junction, and removing the majority of both shield machines in parallel with the freezing work of the rocks, and removing the shield machines left in the ground. Characterized by lining the inside of the hood,
This is a method of joining shield tunnels.

<Description of the Present Invention> The present invention will be described below with reference to the drawings.

First, the shield machine used for construction will be described.

<a> Shielding machine In the present invention, as shown in Fig. 1, a leading shield machine 10 and a trailing shield machine 20 are used.

Both shield machines 10 and 20 are provided with excavation means, earth removal means, excavation means, etc., and have a function of performing an excavation step, an excavation step, and a covering step of the lining material 30 as in the conventional case.

Further, as the excavating means, a known shield excavating means such as a mud pressure type, a limited pressure air type, or an earth pressure balance type can be adopted.

Since both shield machines 10 and 20 have the same structure except for a part of the structure, the structure of the preceding shield machine 10 will be described.

<B> Structure of the leading shield machine The leading shield machine 10 is equipped with a cutter frame 12 as excavating means in the front part of a cylindrical shield body 11.

Center bit 13 provided in the center of the front of the cutter frame 12
Has a structure in which both shield machines 10 and 20 can be slid and retracted when they are joined.

Further, the cutter frame 12 is equipped with a copy cutter for overcutting the ground at the planned joining site.

As shown in FIG. 2, the leading shield machine 10 is a shield body.
A plurality of sets of natural freezing pipes 40a and heat shield freezing pipes 40b are provided on the outer peripheral portion of the hood portion 14 of 11 and the outer peripheral portion of the cutter frame 12.

Further, the hood portion 14 is equipped with an extrusion freeze pipe 50 that radially penetrates into the ground by the extrusion jack 15.

<C> Rock freezing pipe Rock freezing pipe 40a attached to the outer peripheral part of the hood portion 14
Is the main body of freezing work on the ground at the planned joining site,
They are arranged at equal intervals between the inner peripheral surface of the hood portion 14 and the heat insulating material 41.

<D> Heat shield freezing pipe Heat shield freezing pipe 40 provided on the outer peripheral portion of the cutter frame 12
Reference numeral b is a freezing tube for blocking heat generated when the cutter frame 12 is dismantled and for blocking heat conduction to the ground.

Also, the base end of each heat shield freezing pipe 40b is exposed on the back of the cutter frame 12 so as not to affect the rotary excavation of the cutter frame 12, and the pipe extending from the freezing facility is connected when the cutter frame 12 is disassembled. To use.

<E> Extrusion Freezing Pipe The extrusion freezing pipe 50 is intended to supplementally freeze the ground at the junction of the shield tunnel.
They are arranged radially with an acute angle with respect to the axis of the leading shield machine 10 toward the direction of excavation.

The extrusion freezing pipe 50 is hidden in the seat-hold main body 11 during excavation.

Then, at the time of freezing, the push jack arranged on the shield body 11 via the bracket 16 as shown in FIG.
15 is configured so that each extrusion freeze tube 50 can be pushed out of the machine.

The bracket 16 and the extrusion jack 15 are set only when the extrusion freezing pipe 50 is pushed.

Further, the extrusion freezing tubes 50 may be arranged in a plurality of rows in front and behind.

<F> Trailing shield machine The trailing shield machine 20 has the same structure as the leading shield machine 10. Therefore, the same parts as those of the leading shield machine 10 are denoted by the reference numerals in the 20s and the description thereof is omitted.

In addition, the trailing shield machine 20 is configured so that the cutter faces of the two shield machines 10 and 20 are parallel to each other when the leading shield machine 10 and the leading shield machine 10 are joined.

<Operation of the Present Invention> Next, a method for joining shield tunnels will be described.

<a> Overcut of the leading shield machine and promotion of the trailing shield machine As shown in Fig. 3, from just before the leading shield machine 10 arrives at the planned joining site (around 1 m), the leading shield machine is cut with a copy cutter. Digging while overcutting the ground to a larger diameter than the cross section of 10.

When the leading shield machine 10 arrives at the planned joining site, the copy cutter and the center bit 13 are retracted, and then the overcut portion and the cutter frame 12 of the leading shield machine 10 are filled with high-concentration mud water.

On the other hand, the trailing shield machine 20 continues digging toward the leading shield machine 10.

<B> Solidifying material replacement As shown in FIG. 4, the extrusion freezing pipes 50 are set inside the leading shield machine 10, and the extrusion jacks 15 shown in FIG. Penetrate into the ground.

Since the extrusion freezing pipe 50 can penetrate into the ground from the vicinity of the cutter face, the amount of penetration into the ground can be shorter than in the conventional case.

Moreover, since the extrusion freezing pipe 50 penetrates into the overcut portion and the ground by using a copy cutter by using hydraulic pressure, the work of penetrating the extrusion freezing pipe 50 is easy.

Next, the high-concentration muddy water in the cutter frame 12 and the portion overcut by the copy cutter outside the preceding shield machine 10 is solidified by mortar injection or the like to form an annular solidified soil 70 on the outer periphery of the hood portion 14. An internal solidified soil 71 is formed in the cutter frame 12.

During this time, the trailing shield machine 20 continues to dig toward the leading shield machine 10.

<C> Joining of both shield machines As shown in Fig. 5, the trailing shield machine 20 overcuts the ground to a diameter larger than the cross-sectional diameter of the trailing shield machine 20 with a copy cutter from just before the planned joining site. Dig in.

When the trailing shield machine 20 approaches the leading shield machine 10, the center bit 23 is retracted and the trailing shield machine 20 is butted against the leading shield machine 10.

In the meantime, in the preceding shield machine 10, the extrusion freezing pipes 50, the freezing pipes 40a for natural rock, the freezing pipes 40b for heat shield, and the freezing equipment are connected in advance.

<D> Primary dismantling of the leading shield machine, replacement of the extruded frozen pipe set of the trailing shield machine and the solidifying material On the other hand, in the leading shield machine 10, unnecessary equipment such as a rear carriage is carried out.

In the trailing shield machine 20, as shown in FIG. 5, the extrusion freezing pipe 50 is pushed into the ground.

The small amount of penetration of the extrusion freezing pipe 50 and the point of small penetration resistance are the same as in the case of the preceding shield machine 10.

Then, after the high-concentration mud is filled in the overcut portion of the trailing shield machine 20 and the cutter frame 12 of the leading shield machine 10, the high-concentration mud is further solidified with mortar or the like to form the external solidified soil 70 and the inside. The solidified soil 71 is formed.

Furthermore, in the trailing shield machine 20, preparation for freezing is performed.

During this period, unnecessary equipment such as a rear bogie is carried out within the leading shield machine 10.

<E> Freezing work, dismantling work After preparation for freezing work is completed, as shown in Figs. 1 and 2, the freezing plane is circulated in the freezing pipe 40a and the extrusion freezing pipe 50 equipped on both shields 10 and 20. Frozen soil 80 is formed on the ground at the joint site while controlling or controlling the freezing temperature with a temperature measuring tube.

In the present invention, both shield machines 10 and 20 can be disassembled as described below in parallel with freezing.

<F> Dismantling the cutter Next, with the heat shield freezing tube 40b shown in FIG. 2, while cooling the internal solidifying material 71 in the cutter chamber, both shield bodies 11 and 21 are removed as shown in FIG. , Most of both shield machines 10 and 20 are burned off with a gas burner or disassembled by removing bolts.

Since the inside of both cutter frames 12, 22 is replaced with the solidified soil 71, the dismantling work of both shield machines 10, 20 is easy.

The heat shield freezing pipe 40b cools the heat generated during the dismantling work and prevents the heat from being transferred to the natural ground side.

Next, after dismantling and removing the majority, leaving only the shield bodies 11, 21 of both shield machines 10, 20, both shield bodies 11,
Connecting plate 90 is connected between 21.

Regarding the water stopping property during and after dismantling, since the external consolidating material 70 and the frozen soil 80 form a water blocking wall covering the joint parts of the shield bodies 11 and 21, it is possible to prevent flooding and sediment inflow into the tunnel. It can be effectively blocked.

<G> Thawing, thawing soil pouring process Next, the frozen soil 80 formed around the joints of both shield bodies 11, 21 is thawed naturally or forcibly.

After the thawing is completed, the freezing tube 40a, the extrusion freezing tube 50 and the temperature measuring tube are filled with the material, and then the protruding freezing tube 50 and the protruding portion of the temperature measuring tube protruding into the shield bodies 11 and 21 are cut. .

The freezing tube 40a, the extrusion freezing tube 50, and the temperature measuring tube are buried.

<L> Lining Finally, as shown in FIG. 7, a secondary lining 31 is applied to the inside of both shield bodies 11, 21 to complete the joining work.

<Consideration of construction period> The construction period of both construction methods when a tunnel of the same diameter is grounded by the construction method according to the present invention and the conventional construction method will be compared and examined.

FIG. 8 is a process drawing of the tunnel joining process according to the present invention.
The figure is a process drawing of the conventional method.

Directly, the numbers in the figure show the number of days required for each construction, and the numbers in parentheses show the total number of days.

According to the conventional method, freezing work is performed independently from other work such as dismantling work of the leading shield machine and the trailing shield machine, so it takes a total of 430 days from the position confirmation polling work to the completion of the secondary lining work. It takes many days.

On the other hand, in the present invention, since the shield freezing work can be performed in parallel with the dismantling work of the leading shield machine and the trailing shield machine, the number of days required to complete the secondary lining from the position confirmation polling work is about half that of the conventional method. It only takes 230 days.

Especially when comparing only freezing work, in the case of the conventional method of setting a long freezing pipe on the ground from the rear of the shield machine, about 270
Whereas it takes days, in the case of the present invention in which a short freezing pipe is pressed into the ground by hydraulic pressure and the minimum required range is frozen, it takes about 120 days, which is about half the number of days of the conventional method.

As described above, the present invention can significantly shorten the construction period as compared with the conventional construction method.

<Effects of the Present Invention> Since the present invention is as described above, the following effects can be obtained.

<a> Freezing work and dismantling work of the shield machine can be performed in parallel, so the construction period can be greatly shortened.

<B> Conventionally, in order to form frozen soil, a long freezing tube must be set on the ground from the rear of the shield machine, which requires a lot of labor and time to set the freezing tube.

Since the present invention is a method of setting the freezing tube shorter than the conventional one from the vicinity of the cutter face of the shield machine, the setting of the freezing tube is simple, and only the necessary range can be frozen.

<C> Frozen soil needs to be created only in the minimum required range to show the water blocking property at the planned joining site. Therefore, the frozen soil amount can be significantly reduced compared to the conventional method, and the frozen soil subsidence amount can be significantly reduced.

<D> Since the freezing pipe is penetrated into the overcut portion and the ground by the copy cutter by using the hydraulic pressure, the penetration work of the freezing pipe can be performed in an extremely short time and easily.

<E> Construction costs can be significantly reduced by reducing labor costs associated with shortening the construction period and reducing freezing costs by reducing the amount of freezing.

<F> As a means to stabilize the ground at the joints of the abutting shield machines, a laminated structure of a high-strength solidified material layer and frozen soil formed around the solidified material layer was adopted.

Therefore, a high-strength and highly waterproof wall can be formed on the ground to be joined.

<G> The shield machine is dismantled after solidifying the mud remaining in the cutter part of the shield machine to prevent the mud from flowing out.

Therefore, the dismantling work of the shield machine can be performed smoothly.

<H> A conventional shield machine has a structure in which a guide groove in the axial direction is provided on the outer peripheral surface of a skin plate, and a freezing tube is slidably accommodated in the guide groove in the axial direction (Japanese Patent Application Laid-Open No. Sho-06-09) 63-125798).

In this conventional shield machine, since the freezing pipe always projects from the outer peripheral surface of the skin plate, the shield machine becomes a resistance when the shield machine is excavated, which causes a decrease in excavation efficiency and excavation accuracy.

On the other hand, the freezing tube of the present invention can be stored in the hood portion,
Since it does not become a resistance at the time of digging, the digging efficiency and the digging accuracy do not decrease.

Further, in the conventional shield machine, since the freezing tube only slides close to the outer peripheral surface of the skin plate, it is difficult to freeze the natural ground at a place away from the outer peripheral surface of the skin plate.

Therefore, since only a thin frozen soil layer can be created, a problem arises in waterproofness during construction.

On the other hand, since the freezing tube of the present invention can project obliquely forward, the tip of the freezing tube can reach a position apart from the outer peripheral surface of the skin plate.

Therefore, a thick frozen soil layer can be formed around the freezing pipe, and the waterproofness in construction can be improved.

[Brief description of drawings]

Fig. 1: Cross-sectional view of a shield tunnel at the time of joining Fig. 2: Enlarged view of the hood part of the leading shield machine Fig. 3: Illustration of the joining method of the shield tunnel, where the leading shield and trailing shield of the leading shield machine Sectional view of machine when excavating Fig. 4: Explanatory diagram when solidifying mud water inside and outside the preceding shield machine Fig. 5: Explanatory diagram when joining both shield machines Fig. 6: Most of both shield machines Explanatory drawing when removed Fig. 7: Explanatory drawing of secondary lining Fig. 8: Process drawing of tunnel joining process according to the present invention Fig. 9: Process drawing of tunnel joining process by conventional method

Continuation of front page (72) Inventor Etsuro Ushioda 1-25-1 Nishishinjuku, Shinjuku-ku, Tokyo Within Taisei Corporation (56) Reference JP-A-52-121929 (JP, A) JP-A-63-125798 (JP, A) JP-A-63-312499 (JP, A) JP-B-55-7518 (JP, B2)

Claims (1)

[Claims] Claim: What is claimed is: 1. A shield tunnel joining method for joining a tunnel constructed by using two shield machines in the ground, comprising using two shield machines each having a freeze pipe in a hood section and a cutter section. The shield machine is excavated toward the tunnel junction, and both shield machines are butted against each other while stirring the ground at the tunnel junction to a diameter larger than the cross section of the shield machine. The area between the cutters of the machine is solidified with a solidifying material, and the surrounding natural ground that is wider than the solidifying area at the tunnel junction is frozen, and most of both shield machines are dismantled in parallel with the freezing work of the natural ground. A method for joining shield tunnels, characterized by lining the insides of the hoods of both shield machines that have been removed and left in the ground.