JP2003184490A - Primary lining part structure of shield tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To assure the safety of human lives and facilities without collapsing a shield tunnel even if the displacement of a fault occurs due to an probable earthquake in the future in the shield tunnel passing the fault with a fault fracture zone. <P>SOLUTION: In a segment ring structure forming the primary lining part of the shield tunnel, the ring structure is constructed by connecting segments 14. In segment rings 12 adjacent to each other, the segments 14 are arranged staggered by shifting inter-segment joints 5 to each other so as to form a primary lining part body in which the ring structures adjacent to each other reinforce each other. The inter-ring joints of the segment rings 12 are formed of inter-ring joints 16 with a high rigidity and a high strength and inter-ring joints 15 with a rigidity lower than that of the inter-ring joints alternately combined with each other in the longitudinal direction of the tunnel with all the periphery of the tunnel taken as a unit. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shield tunnel which passes through a fault or the like accompanied by a fault crush zone, and a primary lining body (shield segment) of the shield tunnel during an earthquake.
The present invention relates to a primary lining structure that improves seismic performance by flexibly responding to the force of breaking.

[0002]

2. Description of the Related Art A shield tunnel is constructed by assembling a primary lining body consisting of shield segments on the inner surface of the tunnel. Since the force that destroys the structure acts, in that case, it is necessary to improve the seismic performance of the segment ring that constitutes the primary covering so that the primary covering is not destroyed as much as possible. Is.

The conventional techniques for improving the seismic performance of segment rings include a technique for improving the seismic performance of the inter-ring joint by using elastic washers for the inter-ring joint consisting of tensile bolt joints, and the segment itself is configured as a flexible segment. Then, there is a technology to improve the seismic performance of the shield tunnel by absorbing the displacement after the earthquake.

In connection with the above, the problems examined by the present inventor will be described in detail.

In a shield tunnel, in order to impart durability against the force of breaking the segment ring,
Segments 4 between segment rings are often assembled in a staggered arrangement. This is to assemble the segments in a staggered arrangement between adjacent segment rings, and
By connecting the segment rings with a ring-to-ring joint by a rigid connection, the ring can be strengthened and easily broken.

That is, in the case of the segment ring alone, when a force is applied to the ring from the outside, the joint portion between the joint plates connecting the segments in the tunnel circumferential direction serves as a rotation spring, and the ring is formed. Easily destroyed. However, the segments are assembled in a zigzag arrangement between the adjacent segment rings, and the segment rings are connected by the ring-to-ring joint by rigid connection, so that the ring is strengthened and is not easily broken.

Even if the joints between the rings are rigidly connected, if the segments are arranged in the same row in the longitudinal direction of the tunnel between the adjacent segment rings, the segment joints serve as a rotating spring and the ring is weak and easily broken. It On the other hand, even if the segments are arranged in a zigzag arrangement between adjacent segment rings, if the segment rings are connected by a ring-to-ring joint with a flexible connection, each segment ring is mechanically independent of external force. Therefore, the ring is relatively easily broken as in the case of the segment ring alone.

In the zigzag arrangement described above, when the inter-ring joint is destroyed by an earthquake and the structure has only one ring, the staggered effect exhibited by the adjacent segment rings disappears, and many joints are provided in the circumferential direction of the tunnel. In the single ring structure, the joint between the segments serves as a rotating spring, the ring becomes unstable, and the risk of collapse due to surrounding earth pressure and water pressure increases.

Referring to FIG. 1, FIG. 1A shows a perspective view of a shield tunnel, and the shield tunnel 3 has a segment 4 between a first ring 1 and a second ring 2.
By arranging in a staggered arrangement, the primary lining body is constructed. FIG. 1 (B) is an explanatory view showing a modeled action of the inter-segment joints in the first ring 1 and the second ring 2 and the inter-ring joints when an external stress acts on the segment rings.

In FIG. 1 (B), two circles indicate a first ring 1 and a second ring 2, and a double circle indicates a rotary spring (symbol of Kθ in an inter-segment joint 5 connecting the segments in the tunnel circumferential direction). Is shown). Further, a plurality of sets each including two wavy lines that are shown by changing the arrangement angle indicate the direction of the force acting on the inter-ring joint 6, and the wavy line indicated by Ksr indicates the radial direction of the inter-ring joint 6 (inward and outward directions). ), The wavy line indicated by Kst indicates the movement (spring force) in the circumferential direction (tangential direction).

In FIG. 1B, the first ring 1 and the second ring 1
When an external force that deforms (breaks) the ring 2 acts, the inter-segment joint 5 becomes a rotary spring (Kθ),
When the first ring 1 and the second ring 2 are independent of each other, each ring connects the inter-segment joint 5 to the rotary spring (K
There is a problem that it is easily deformed as θ) and leads to tunnel collapse.

When all of the ring-to-ring joints 6 are flexible joints (this structure is known as described above), an external force that deforms the first ring 1 and the second ring 2 acts. At this time, the ring joint 6 moves in the radial direction (inward / outward direction) indicated by Ksr acting on the ring joint 6 and the circumferential direction (tangential direction) indicated by Kst.
The first ring 1 and the second ring 2 are mechanically independent of each other by following the movement (spring force) toward each other.
θ) is a rotating spring and is easily deformed, leading to tunnel collapse.

[0013]

As described above, in the shield tunnel, the ring of the shield segment that constitutes the primary lining body is deformed by the surrounding earth pressure and water pressure, and becomes unstable. In the technology to improve the seismic performance of the inter-ring joint by shifting the inter-segment joint between adjacent rings in the tunnel circumferential direction to form staggered segments and using elastic washers for the ring-joint consisting of the tensile bolt joints described above. As described above, each ring is mechanically independent of external stress, and since each ring is independent, it can only function as a single ring and cannot deal with it.

As a result of various studies on the method for avoiding the above-mentioned dangers, the present inventor has determined the tensile force in the tunnel axial direction and the rigidity in the tunnel radial direction and the tunnel circumferential direction of one of the ring joints connecting segment rings. By making it higher and lowering the tensile rigidity in the tunnel axial direction of the other ring joint, the displacement in the tunnel axial direction generated during an earthquake is absorbed on the side of the ring with low rigidity and the ring joint with high rigidity is also absorbed. Can hold a staggered arrangement with
This makes it possible to ensure that two adjacent ring structures are retained even after a large fault displacement has occurred after the earthquake. In other words, by retaining the staggered structure of the two rings in this manner and maintaining the staggered effect, it is possible to prevent the ring structure from collapsing due to the surrounding earth pressure and water pressure. Obtained.

The present invention has been proposed on the basis of the above findings, and its purpose is to generate a fault displacement due to an earthquake that may occur in the future in a shield tunnel passing through a fault accompanied by a fault crush zone. In this case, the safety of human life and facilities should be ensured without the collapse of the shield tunnel.

[0016]

In order to achieve the above-mentioned object, the present invention is constructed as follows.

A first aspect of the present invention is, in a primary lining structure of a shield tunnel, constructing a ring structure by connecting shield segments and staggering the segment joints of adjacent rings to form an inter-ring joint. A primary lining body is constructed such that the segment rings to be joined together reinforce each other, and the ring-to-ring joint that connects the segment rings in the longitudinal direction of the tunnel has high rigidity and high yield strength with the entire circumference of the ring as one unit. Ring joint and the ring joint having a lower tensile rigidity in the tunnel axial direction than the above ring joint, and the ring joint having high rigidity and high yield strength and the low rigidity. It is characterized in that the ring-to-ring joints are alternately arranged every one row.

According to a second aspect of the present invention, in the first aspect, the ring joint having a low rigidity is arranged at the side edge of the segment opposite to the side where the ring joint having a high rigidity and a high yield strength is provided. The eaves, which extend over the side edges of the rings joined to each other, are fixed to the side edges, and the eaves are provided so as to cover the openings between the side edges of the other segment ring by the eaves. To do. By arranging a water-swelling rubber having a water-stopping function on the segment side surface of this eaves,
It is possible to prevent the infiltration of groundwater even after the earthquake.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the ring-to-ring joint having low rigidity is inserted into a bolt insertion hole formed in the main girder to be joined to each other, and is arranged on a side surface of the main girder. It is characterized in that the nut is fastened via an elastic washer designed to exert the required performance of the installation.

[0020]

In the present invention, the primary lining body of the shield tunnel is constructed by connecting the shield segments to construct a ring structure, and shifting the joints between the segments between the adjacent rings to form a zigzag structure, thereby adjoining the adjacent ring structures. Form a strong primary lining body that reinforces each other.

Further, since the ring joints are provided such that the ring joints having high rigidity and high yield strength and the ring joints having low rigidity are alternately arranged in the tunnel axial direction, the displacement generated at the time of earthquake The high rigidity and high yield strength ring joint can be prevented from being broken by absorbing
Therefore, even if two earthquakes occur, the two adjacent ring structures can be retained without fail, so that even if a large fault displacement occurs after the earthquake, the two-ring staggered structure can be retained. The staggered structure of the two rings and the existence of the joint between the rings with high rigidity and high yield strength can be combined to maintain the staggered effect, and the ring structure collapses due to earth pressure and water pressure in the surroundings. It is possible to prevent this.

Further, when the opening amount of the ring joint having low rigidity exceeds the allowable opening amount of the water blocking rubber arranged between the rings, the earth and sand around the tunnel and groundwater violently flow into the tunnel. Is concerned. Here, by covering the spaces between the rings with the eaves structure fixed to one side edge of one of the segment rings, the eaves covers the openings even if a large opening occurs, so Can prevent soil and groundwater around the tunnel from flowing into the tunnel.

[0023]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described with reference to FIGS.

FIG. 2 shows a shield tunnel 1 according to the present invention.
3 is a plan explanatory view showing the direction (arrow) of the force acting on the shield tunnel 13 when 3 passes through the fault crush zone 11, and FIG. 3 is the segment ring 12 when the force in the direction of the arrow of FIG. 2 acts. It is a plane explanatory view showing a mode in which is deformed.

FIG. 4 (A) is a side explanatory view showing a process of assembling the segment ring 12 with an eaves inside a tunnel, and FIG. 4 (A) shows the ring ring joint having a low rigidity of the segment ring 12 with an eaves. It is explanatory drawing which shows the effect | action of the eaves 10 in the case of. FIG. 5 is a perspective view of the segment 14 with an eaves, FIG. 6 is a cross-sectional view of the joint structure, and FIG. 7 is a conceptual diagram of the relationship between the load (P) and the opening (δ) of the inter-ring joint.

As shown in FIGS. 2 to 4, the fault crush zone 11
Segment ring 1 of shield tunnel 13 passing through
In 2 (primary lining body), each segment 14 is connected by a segment joint in the tunnel circumferential direction, and is connected by an inter-ring joint in the tunnel longitudinal direction, and the segments 14 of adjacent rings are arranged in a staggered manner. It is provided in.

In each of the ring joints, the thick line indicates the ring joint 16 having high rigidity and high yield strength, and the thin line indicates the ring joint 15 having low rigidity. As shown in the drawing, the ring joint 16 having high rigidity and high yield strength and the ring joint 15 having low rigidity are provided in combination in the tunnel longitudinal direction, with each joint provided on the entire circumference of the tunnel as one unit. That is, the inter-ring joints 15 having high rigidity and low yield are provided every other row or every other row of the inter-ring joints 15 having low rigidity. The figure shows an example in which high-rigidity inter-ring joints 16 and low-rigidity inter-ring joints 15 are alternately provided.

Segment 14 and ring-to-ring joint 15,
An example of the structure of 16 is shown in FIGS. As shown in FIG. 5, the segment 14 is a concrete filling steel segment in the illustrated example, and the segment 14 is
The two main girders 7 arranged in parallel are connected by a plurality of vertical ribs 8 arranged at a predetermined interval, the ends of each main girder 7 are connected by a joint plate 9, and the main girder 7 and the joint are further joined. A skin plate 17 is connected to the outside of the plate 9 to form a steel shell, and the inside of the steel shell is filled with a filling concrete 18, and a small-diameter reinforcing wire mesh 19 is embedded in the filling concrete. Has been done.

The eaves 10 is fixed to the back surface of the skin plate 17 on one side of the segment 14 in the longitudinal direction of the tunnel, and is provided while traveling a predetermined length from the main girder 7 on one side and the joint plates 9 on both sides. .

When the segment 14 is assembled into the ring, the eaves 1
The one side of the segment where 0 is provided is connected by an inter-ring joint 15 having low rigidity shown in FIG. 6 (A) or (B),
The other side of the segment is connected by a highly rigid and high yield strength inter-ring joint 16 shown in FIG. 6 (C).

The inter-ring joint 15 having a low rigidity shown in FIG. 6 (A) has a joining bolt 21 in the bolt insertion hole 20 of the main girder 7 of the segment 14 to be joined in a staggered arrangement in the longitudinal direction of the tunnel.
The elastic washer 22 is interposed on one side of the two main girders 7 which are inserted through each other and are joined with each other by the nut 23, thereby giving the ring joint 15 low rigidity. Figure 6
In the inter-ring joint 15 having low rigidity shown in (B), elastic washers 22 are interposed on both sides of the two main girders 7 which are joined to each other, and they are joined by nuts 23, so that the ring is made more ring-shaped than in FIG. 6 (A). It is provided so that the rigidity of the joint 15 is low.

In the ring joint 16 with high rigidity and high yield strength shown in FIG. 6 (C), the main girder 7 on the side opposite to the side where the eaves 10 of the segments 14 connected in a staggered arrangement in the longitudinal direction of the tunnel are provided.
The joint bolts 21 are inserted into the bolt insertion holes 20 and the two main girders 7 joined to each other are directly joined by the nuts 23, so that the ring joint 16 has high rigidity and high yield strength. . The inter-ring joint structure shown in FIG. 6 is an example, and the inter-ring joint 1 having a structure other than this and having low rigidity is used.
5 and the ring joint 16 having high rigidity and high yield strength may be configured.

The main element of the present invention is that the primary lining of the segment ring 12 is formed by combining ring joints 15 having low rigidity and ring joints 16 having high rigidity and high yield strength alternately or non-alternately in the longitudinal direction of the tunnel. Building the body and covering the joints, which are joined by the inter-ring joints 15 with low rigidity, with the eaves 10.

FIG. 4A is a side view showing the process of assembling the segment ring 12. As shown in the figure, the eaves-equipped segment 14 is arranged in the tunnel so that the eaves 10 are on the front side, and is sequentially assembled in a ring shape by an erector, and the rigidity is low for each ring 12, The ring-shaped joint 15 having a high yield strength and the ring-shaped joint 16 having a high rigidity and a high yield strength are alternately used to couple the rings to construct a primary lining body. At this time, as the segments 14 are assembled in a ring shape, a ring-shaped eave is formed by the entire eaves 10 of each segment 14, and the ring-shaped eaves covers the outer circumference of the segment ring 12 that was constructed in advance. Is built as.

The operation of the primary lining body according to the present invention will be described.

As shown in FIG. 2, when a shearing force in the direction of the arrow acts on the straight shield tunnel 13 passing through the fault crush zone 11 due to an earthquake or the like, as shown in FIG. The primary lining body is bent, and the segment ring 12 of the primary lining body has both the ring-shaped joint 15 having low rigidity and the ring-shaped joint 16 having high rigidity and high yield strength on the inner peripheral side of the bent portion. The initial pressure welding condition is maintained.

On the other hand, on the outer peripheral side of the bent portion, the ring joint 16 having high rigidity and high yield strength maintains the initial joint state, but the ring joint 15 having low rigidity is compressed in the initial state. Elastic washer 22 (FIG. 6 (A),
(Shown in (B)) expands, thereby creating openings 24 between the segment rings, and the primary lining body flexibly follows the bend of the shield tunnel 13 through the occurrence of the openings 24. There is. As a result, the segment ring 12 when the shield tunnel 13 is bent
It is possible to secure the stability of the ring and eliminate the risk that the primary lining body will be deformed by surrounding earth pressure and water pressure.

Further, as shown in FIG.
4 occurs, the part of the opening 24 of the segment ring 12 is covered with the eaves 10 that travels from one side edge of the segment ring 12 and extends to the one side edge of the other segment ring 12. It is possible to prevent earth and sand, groundwater, etc. from violently entering the ring through the openings 24.

FIG. 7 is a conceptual diagram showing the relationship between the load (P) acting on the ring joint and the aperture (δ). As can be seen from the figure, in the ring joint having high rigidity and high yield strength, when the load exceeds a certain value, the mesh opening progresses at once, that is, the bolt of the ring joint is broken. On the other hand, in the case of ring joints with low rigidity, the mesh opening increases in proportion to the increase in load, that is, the bolts of the ring joints are not broken and the outer peripheral side of the segment ring is tunnel bent during an earthquake. It shows that it can be bent smoothly following the part. From this figure as well, the effectiveness of using the joints of the ring-shaped joint 15 having low rigidity and the ring-shaped joint 16 of high rigidity and high yield strength in the present invention in an alternating or non-alternate combination in the tunnel longitudinal direction is understood. To be done.

[0040]

As described above, according to the present invention,
In a shield tunnel that passes through a fault with a fault crush zone, the seismic performance of the segment ring, which is the primary lining body, has been improved, so even if a fault displacement due to an earthquake that may occur in the future occurs, The safety of human life and facilities can be secured without the shield tunnel collapsing.

[Brief description of drawings]

FIG. 1 (A) is a perspective view of a shield tunnel, and FIG. 1 (B) is a model of the inter-segment joint and the spring action of the inter-ring joint when external stress acts on the first and second segment rings. FIG.

FIG. 2 is a plan view showing a direction (arrow) of a force acting on a primary lining body according to the present invention due to a fault displacement in a shield tunnel passing through a fault crush zone.

FIG. 3 is a plan explanatory view showing a mode in which the segment ring is deformed when a force in the direction of the arrow in FIG. 2 is applied.

FIG. 4 (A) is a side view showing a step of assembling a segment ring with an eaves inside a tunnel, and FIG. 4 (B) is a side view.
It is explanatory drawing which shows the effect | action of an eaves when an opening arises on the side of the ring coupling which has a low rigidity of the segment ring with an eaves.

FIG. 5 is a perspective view of a segment with an eaves.

6A and 6B are cross-sectional views of a ring joint having low rigidity and high yield strength, and FIG. 6C is a cross-sectional view of a ring joint having high rigidity and high yield strength.

FIG. 7 is a conceptual diagram showing in a graph the relationship between the load (P) and the opening (δ) of the ring-to-ring joint.

[Explanation of symbols]

1st ring 2 second ring 3 shield tunnel 4 segments 5 Segment joint 6 Ring joint 7 main girder 8 vertical ribs 9 Joint plate 10 eaves 11 Fault fracture zone 12 segment ring 13 Shield tunnel 14 segments 15 Ring joint with low rigidity 16 High rigidity and high yield strength ring joint 17 skin plate 18 Filling concrete 19 Reinforcing wire mesh 20 bolt insertion hole 21 bolts 22 Elastic washers 23 opening

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshima diameter             20-1 Shintomi, Futtsu City Nippon Steel Co., Ltd.             Inside the surgical development headquarters (72) Inventor Minoru Nakamura             2-6-3 Otemachi, Chiyoda-ku, Tokyo New Japan             Steelmaking Co., Ltd. (72) Inventor Akira Kawamura             2-6-3 Otemachi, Chiyoda-ku, Tokyo New Japan             Steelmaking Co., Ltd. F-term (reference) 2D055 CA01 GC05 LA19

Claims (3)

[Claims] 1. A primary lining structure for a shield tunnel, wherein segments are joined together by inter-ring joints by linking shield segments to construct a ring structure and staggering the segment joints of adjacent rings. A ring joint for connecting the segment rings in the longitudinal direction of the tunnel, which constitutes a primary lining body so that the rings reinforce each other, is a ring joint with high rigidity and high yield strength in which the entire circumference of the ring is one unit. And a ring inter-joint having a low tensile rigidity in the tunnel axial direction as compared with the ring inter-joint, and the ring joint having high rigidity and high yield strength, and the ring joint having low rigidity. A primary lining structure for a shield tunnel, which is characterized by alternately arranging every row. 2. A ring which is joined to a side edge of the segment opposite to the side where the ring joint having high rigidity and high yield strength is provided and where the ring joint having low rigidity is arranged. The primary covering of the shield tunnel according to claim 1, wherein an eave extending over the side edge of the shield tunnel is fixed, and the eave is provided so as to cover the opening between the other segment ring and the eave. Construction. 3. The ring joint having low rigidity is designed such that a bolt is inserted into a bolt insertion hole formed in the main girders to be joined to each other and the side girders have a required performance. The primary lining structure of the shield tunnel according to claim 1 or 2, wherein a nut is fastened via an elastic washer.