JP2000080892A - Joint structure and joint method of steel segment - Google Patents

Abstract

(57) [Summary] [Problem] To improve the tensile strength of bolts for joining steel segments by quality and assurance, to reliably and firmly join the steel segments, and to maintain high waterproofness. It is an object to provide a joint structure of a segment and a joint method thereof. SOLUTION: Steel segments 1 each having a main girder 5 and a joint plate 7 extending in a circumferential direction and an axial direction of a tunnel a are joined to each other. At this time, the main beam 5 is connected to the joint plate 2 with a plurality of short bolts 4 penetrating the joint plate 7 in the circumferential direction of the tunnel a.
And a plurality of high strength bolts 3 penetrating in the axial direction of the tunnel a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure and a joint method for steel segments, and more particularly, to a lining or a primary structure of a steel structure in which a ground of a tunnel is constructed by only a plurality of steel segments. A steel-concrete composite lining body constructed by casting concrete as a secondary lining inside a steel segment installed as a lining, and concrete cast as a secondary lining It is applied when lining with a lining of steel / reinforced concrete composite structure constructed by arranging a plurality of reinforcing bars inside.

[0002]

2. Description of the Related Art As a method for lining a ground of a tunnel immediately after excavation, the present applicant has hitherto disclosed a method of constructing a lining body of a steel structure by installing a plurality of steel segments on the ground of a tunnel. A method of constructing a steel-concrete composite lining by installing multiple steel segments as primary lining on the ground of the tunnel and casting concrete inside as secondary lining. A lining method was developed to construct a reinforced body of steel-reinforced concrete composite structure by arranging reinforcing steel in concrete placed as secondary lining inside the segment.

As a method of efficiently and economically constructing a tunnel having a large cross section, the applicant has first constructed a rectangular cylindrical outer shell 30 as shown in FIG. A large-section tunnel construction method (MMST method) for constructing a large-section tunnel A by excavating earth and sand in the outer shell 30 has also been developed.

[0004] At that time, the outer shell portion 30 excavates a plurality of single shield tunnels a (hereinafter referred to as “simple tunnels a”) in close proximity, and then joins the single tunnels a so as to be continuous with one space. It is constructed by continuously casting concrete 31 therein.

FIG. 8 shows an example of a steel segment used in the construction method of these tunnels. A steel segment 32 has a plurality of main girders 33 installed in parallel in the circumferential direction of the tunnel as shown in FIG. The joint plate 3 is provided at both ends of the main girder 33.
4 and a plurality of vertical ribs 35 are arranged at predetermined intervals in the axial direction of the main girder 33 between the adjacent main girder 33 to form a rectangular lattice frame. It is formed by attaching a skin plate 36 to the ground side.

A method of joining steel segments 32 adjacent to each other in the circumferential direction of the tunnel is described in, for example, FIG.
As shown in (a), a method is known in which the joint plate 34 is bolted and joined with a plurality of short bolts 37 penetrating in the circumferential direction of the tunnel.

[0007]

However, in the method in which the joint plate 34 is bolted with the short bolts 37, the transmission of bending stress and tensile stress at the joint portion is limited.
Since the stress is concentrated on the joint plate 34, the joint plate 34 is easily deformed as shown in FIG. 9B, and the axial force of the short bolt 37 varies. There was a problem that a predetermined tensile force could not be transmitted.

[0008] Further, when the joint plate 34 is deformed in this way, there is another problem that the role of the shield tunnel as a lining body for maintaining the waterproofness and maintaining the shape cannot be sufficiently achieved.

Therefore, in order to increase the rigidity of the joint portion and to transmit a reliable tensile force, for example, as shown in FIG. 10, the main girder 33 is joined to the joint plate 38 by a plurality of high-strength bolts 39. Although high-strength bolt friction joining is also being studied, after the steel segment 32 is installed, the axial load of the bolt varies due to the influence of the load at the time of construction such as jack thrust. There were issues such as difficulty in management.

Further, in the case of the large section tunnel shown in FIG. 7, the short bolt 37 receives the tensile force due to the bending moment in the single tunnel a, and receives the tensile force as the tensile steel material in the large section tunnel A, respectively. The sum of these two stresses is designed as the design stress.

In general, these short bolts 37 are
When assembling the steel segment 32, the allowable tensile stress of 8
An initial introduction axial force of about 0% is introduced. In the case of a large-section tunnel, in order for the short bolt 37 to secure a predetermined safety factor with respect to the section force of the large-section tunnel, the following conditions must be satisfied.

[0012] The pulling force of the short bolt 37 must be within the designed value when the single tunnel a is constructed. This is because, if the short bolt 37 has a tensile force equal to or greater than the design value when the single tunnel a is constructed, there is no room for the tensile force of the bolt when the large-section tunnel A is constructed. The initial axial force of the short bolt 37 is
This is almost constant for all bolts at the time of casting. This occurs when the initial introduction axial force of the short bolts 37 varies, and the rigidity differs for each of the short bolts 37. This is because the distribution ratio of the tensile force varies.

However, in constructing the actual large-section tunnel A, there are various problems as described below. When the single tunnel a is constructed, even when the initial axial force of the short bolt 37 introduced at the time of assembling the steel segment 32 is initially constant, a large variation occurs when the concrete 31 is poured in the construction of the large-section tunnel A.

This is because the steel segment 32 receives various construction loads (jack thrust, connection construction load, etc.) and is deformed during the period from the installation of the steel segment 32 to the placement of the concrete 31. And steel segments 32
This is because it gradually adapts to the ground surface while gradually deforming.

The variation in the axial force is caused by the concrete 31
There is no particular problem if the axial force can be adjusted again by introducing the axial force before casting. However, since the torque value greatly varies due to the influence of rust and water droplets, the time has elapsed since the steel segment 32 was installed. It is not possible later to introduce a constant axial force into the bolt again.

Further, in order to confirm that the tensile force due to the cross-sectional force of the large-section tunnel A has a reliable tensile strength, it is necessary to set the inside of a single tunnel a joined so as to form one continuous space. It is necessary to grasp the tensile force acting on the short bolt 37 before placing the concrete 31. However, when assembling the steel segment 32, the initial axial force of about 80% of the allowable tensile stress is introduced. Therefore, the tensile force acting on the short bolt 37 cannot be grasped.

For this reason, it is not possible to cope with a case where a tensile force exceeding a design value is applied to some of the short bolts 37 due to some construction load. As described above, if one kind of short bolt is used to cope with both the end face force of the single tunnel and the cross-sectional force of the large-section tunnel, the above-described various problems occur. Cannot provide quantitative quality assurance for the bolt strength.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and the quality and the assurance of the tensile strength of a joint bolt can be ensured so that steel segments can be securely and firmly joined to each other, and high water stopping performance can be maintained. It is an object of the present invention to provide a joint structure of a steel segment and a joint method thereof.

[0019]

In order to solve the above-mentioned problems, a joint structure of a steel segment according to the first aspect of the present invention comprises a main girder and a joint plate extending in a circumferential direction and an axial direction of a tunnel, respectively. In the joint structure of the steel segment having the above, the joint plate is joined with a plurality of short bolts penetrating in the circumferential direction of the tunnel, and the main girder is joined with the joint plate with a plurality of high-strength bolts penetrating in the axial direction of the tunnel.

According to a second aspect of the present invention, in the joint structure of a steel segment, the contact surface between the main girder and the joint plate is formed in a rough surface or an uneven shape. According to a third aspect of the present invention, there is provided a joint method of a steel segment having a main girder and a joint plate extending in the circumferential direction and the axial direction of the tunnel, respectively, wherein the joint plate is first penetrated in the circumferential direction of the tunnel. The main girder is joined with a plurality of short bolts, and then the main girders are joined with a plurality of high-strength bolts penetrating in the axial direction of the joint plate and the tunnel.

According to a fourth aspect of the present invention, in the joint method for a steel segment, after excavating while excavating the single shield tunnel with the steel segment, the concrete is poured into the single shield tunnel to a predetermined thickness to form the tunnel. When constructing, in the method of joining steel segments to join steel segments, when excavating a single shield tunnel, steel segments are joined with a plurality of short bolts penetrating in the circumferential direction of the tunnel, and then concrete is Prior to casting, the steel segments are joined together with a plurality of high-strength bolts that penetrate the joint plate and the tunnel in the axial direction.

According to a fifth aspect of the present invention, there is provided a joint method for a steel segment, wherein a plurality of single shield tunnels are excavated while being covered with steel segments, and then concrete is poured into the single shield tunnel to form an outer shell portion. When building, and then excavating the earth and sand inside this outer shell part to construct a tunnel with a large section,
In a method of joining steel segments to join steel segments, when excavating a single shield tunnel, the steel segments are joined with a plurality of short bolts penetrating in a circumferential direction of the tunnel, and then before concrete is poured ( Alternatively, immediately before casting concrete), the steel segments are joined with a plurality of high-strength bolts penetrating in the axial direction of the joint plate and the tunnel.

According to a sixth aspect of the present invention, in the method of the fourth or fifth aspect, the contact surface between the main girder and the joint plate is formed as a rough surface or an uneven shape. The joint method for a steel segment according to claim 7 is a method according to claim 4, 5 or 6.
, A part of the bolt hole for fastening the high-strength bolt is formed when the steel segment is manufactured, and the rest is formed when the high-strength bolt is fastened.

[0024]

1 to 5 show an embodiment of the present invention. A plurality of steel segments 1 are adjacent to each other in the circumferential direction and the axial direction of a tunnel a on the ground surface of a tunnel A. ,
And it is installed by joining mutually.

At this time, in particular, the steel segments 1 which are adjacent to each other in the circumferential direction of the tunnel a are connected to each other by a high-strength bolt friction joint with a joint plate 2 and a plurality of high-strength bolts 3 as shown in FIG. They are joined by bolts 4 with bolts.

FIG. 2 (a) shows an example of a steel segment used here. As shown, a plurality of main girders 5 extend in the circumferential direction of the tunnel a in parallel with each other. A plurality of longitudinal ribs 6 are attached between the girders 5 and 5 at predetermined intervals in the axial direction of the main girders 5, and a joint plate 7 and a reinforcing plate 8 are attached between ends of the main girders 5 and 5, respectively.

Further, a skin plate 10 is attached to the ground side of the lattice-shaped frame 9 formed in a rectangular shape from these members. These members are joined to each other by welding, bolting, or the like.

The main girder 5, the vertical ribs 6 and the joint plate 7 are all formed in a strip shape with a predetermined beam height (height). In addition, a plurality of bolt holes 11 for fastening the high-strength bolt 3 are formed at predetermined intervals at the end of the main girder 5, and a bolt hole 12 for fastening the short bolt 4 and a vertical hole for passing the joint plate 2 are formed in the joint plate 7. 13 are formed respectively.

The bolt holes 11 and 12 are respectively formed at predetermined intervals in the axial direction of the main beam 5 and the joint plate 6 and in parallel. The vertical holes 13 are formed on both sides of the main girder 5 and are formed in a rectangular shape slightly larger than the cross-sectional shape of the joint plate 2 so that the joint plate 2 can slide freely in the axial direction of the main girder 5. I have.

The vertical hole 13 is also formed in the vertical rib 6A adjacent to the joint plate 7 when the joint plate 2 is particularly long. The vertical rib 6 is reinforced by a reinforcing rib 6a as necessary so as to have a sufficient strength as a reaction force receiving a propulsion reaction force of a shield machine that excavates the tunnel a. Installed at intervals.

The vertical rib 6A is formed larger than the vertical rib 6 in order to compensate for the shortage of the cross section due to the provision of the vertical hole 13. The steel segment 1 thus formed
Are installed adjacent to each other in the circumferential direction and the axial direction of the tunnel a. In particular, the joint plates 7 of the steel segments 1 adjacent to the circumferential direction of the tunnel a are butted against each other.

The short bolt 4 is fastened to the bolt hole 11 of the joint plate 7. The joint plate 2 is bridged between the side portions of the main girder 5 through the vertical holes 12, and the high-strength bolts 3 are fastened to the bolt holes 2 a of the joint plate 2 and the bolt holes 11 of the main girder 5.

In this manner, the steel segments 1 and 1 which are adjacent to each other in the circumferential direction of the tunnel a are joined by the bolt joining with the plurality of short bolts 4 and the high strength bolt friction joining with the joint plate 2 and the plurality of high strength bolts 3. .

At this time, the contact surface between the end of the main girder 5 and the joint plate 2 may be formed rough, or as shown in FIG.
By forming a large number of extremely small irregularities 14 on the contact surface as shown in FIG. 2, the friction coefficient of the contact surface can be significantly increased.

As shown in FIGS. 3 (a) and 3 (b), the workability can be improved by joining the ends of the main girder 5 with two thinly formed joint plates 2. In addition, it is possible to easily absorb an error in the construction of the segment joint.

The lining of the tunnel a (lining)
Is a steel structure, only the steel segment 1 is installed as a main body structure (frame) as shown in FIG. 1, and if the lining is a steel-concrete composite structure, as shown in FIGS. 4 (a) to 4 (c). As shown in the figure, concrete 15 is cast into a predetermined thickness as a secondary lining inside a steel segment 1 installed as a primary lining, and in the case of a lining body of a steel / reinforced concrete composite structure, After reinforcing bars 16 are provided inside the steel segments 1 as secondary lining, concrete 15
Is cast at a predetermined thickness.

In particular, in the case of a tunnel having a large cross section as shown in FIG. 5, in order to construct an outer shell 17 of a steel / reinforced concrete composite structure, the tunnel is excavated while lining with a plurality of steel segments 1 and one. Reinforcing reinforcing bars 16 are arranged in a single tunnel a joined so as to be continuous with two spaces,
After that, concrete 15 is cast. And
The earth and sand inside the outer shell 17 thus formed is excavated.

When a large-section tunnel A is constructed as shown in FIG. 5, a steel / concrete composite structure may be used without reinforcing reinforcement. In such a configuration, a method for joining steel segments according to the present invention will be described next (see FIGS. 6 (a) to 6 (e)).

At the tail of the shield machine (not shown), a plurality of steel segments 1 are installed on the ground surface of the tunnel so as to be adjacent to each other in the circumferential direction and the axial direction of the tunnel.
At this time, the steel segments 1 adjacent in the circumferential direction of the tunnel
As shown in FIG. 6B, the joint plate 7 is closely attached so that no gap is formed, and the two bolt holes 12 are aligned. Next, the short bolt 4 is fastened to the bolt hole 12 of the joint plate 7 to join the steel segments 1 adjacent to each other in the circumferential direction of the tunnel. Next, as shown in FIG. 1, when lining the ground of the tunnel with only steel segments, the steel segments 1
After being assembled, it is gradually deformed by receiving various loads during construction, and the axial force of the bolt fluctuates, so these effects disappear, and after the segment has fully adapted to the ground surface,
The main girders 5 are friction-welded to each other by the joint plate 2 and the plurality of high-strength bolts 3.

The joint plate 2 has a vertical hole 1 in one joint plate 7.
3 is inserted into the vertical hole 13 of the other joint plate 7 and bridges between the ends of the two main girders 5. And bolt hole 11 of main girder 5
The high-strength bolt 3 is fastened to the bolt hole 2 a of the joint plate 2 formed corresponding to the bolt hole 11.

The high-strength bolt 3 may be fastened before the concrete 15 is cast.
It is preferable to fasten immediately before casting because the steel segment 1 is not affected by the load at the time of construction and the steel segment 1 is sufficiently adapted to the ground, so that subsequent deformation almost stops.

When the high-strength bolt 3 is fastened, there may be a case in which the high-strength bolt 3 cannot be fastened due to misalignment or misalignment between the joints of the steel segments 1 due to a load during construction such as jack thrust.

As a countermeasure in such a case, when the steel segment 1 is installed (assembled), a temporary joint bolt (not shown) that penetrates the bolt hole 2a of the joint plate 2 and the bolt hole 11 of the main girder 5 is used. 5 are temporarily joined, the temporary joining bolt is pulled out when the concrete 15 is poured, and then the high-strength bolt 3 is fastened.

As another method of temporarily joining the main girders 5, a temporary joint plate (not shown) is attached between the ends of the main girders 5, and the temporary joint plate and the main girders 5 are temporarily joined. There is also a method of temporarily joining with joining bolts (not shown).

There is also a method in which some of the bolt holes 11 and 2a are formed initially, and the remaining bolt holes are formed when the high-strength bolt 3 is fastened. By doing so, it is possible to easily absorb construction errors such as manufacturing errors and assembly errors of the steel segments 1, and in the case of high-strength bolt friction joining, it is not possible to drill a large bolt hole due to its quality. Since the assembling accuracy is required, by forming the bolt hole when fastening the high-strength bolt, the construction accuracy can be remarkably improved. In addition, a high waterproofness of the joint can be ensured.

Further, as shown in FIG. 3, by joining the ends of the main girder 5 with the two thinly formed joint plates 2, it is easier to deal with errors in the joints. .

When the lining body is constructed only of the steel segments 1, the construction is completed with this, but the lining body is made of steel.
When a concrete composite structure is used, FIG.
As shown in (c), concrete 15 is poured into steel segment 1 to a predetermined thickness, and reinforcing steel 16 is arranged in concrete 15 when a steel / reinforced concrete composite structure is formed.

Further, in the case of a tunnel having a large cross section as shown in FIG. 5, a single tunnel a covered with a plurality of steel segments 1 and joined so as to be continuous to one space a
Reinforcing reinforcing bars 16 are arranged inside, and concrete 15
And the outer shell body 17 is constructed. Then, a large-section tunnel A is constructed by excavating earth and sand in the outer shell 17 with a general-purpose heavy machine or the like.

In this way, it is possible to form a joint structure having a reliable tensile strength against stress generated particularly in a large-section tunnel.

[0050]

The present invention has the above-described structure,
Particularly when constructing a large-section tunnel, the bolt that receives the tensile force due to its sectional force in the large-section tunnel is completely separated from the short bolt that receives the tensile force due to the sectional force in the single-piece tunnel, so that the bolt has a large-section tunnel. Since it can be confirmed that it has a reliable tensile strength against the tensile force due to the cross-sectional force of the cross section, it is possible to quantitatively assure the bolt strength in the large-section tunnel, thereby reducing the stress generated in the large-section tunnel. A joint structure having a reliable tensile strength can be provided.

Also, for the sectional force of the large section tunnel,
By using high-strength bolt friction joints with high joint rigidity for the steel segment joints, it is excellent in crack prevention and toughness, especially for composite structures of steel and concrete or steel and reinforced concrete that are resistant to repeated loads during earthquakes. A large section tunnel with a structure can be constructed.

Further, when assembling the steel segments, only the short bolts need to be fastened, so that any errors in the construction such as manufacturing errors and assembling errors of the steel segments are confirmed before fastening the high-strength bolts. The accuracy of construction can be improved by forming bolt holes for this purpose.

In particular, in the case of high-strength bolt friction welding, a high level of assembly accuracy is required because a large bolt hole cannot be drilled in terms of quality. Can be significantly improved. In addition, a high waterproofness of the joint can be ensured.

[Brief description of the drawings]

FIG. 1 is a partial perspective view of a shield tunnel constructed only of steel segments.

2A and 2B show a joining portion between steel segments adjacent to each other in a circumferential direction of a tunnel, where FIG. 2A is a perspective view showing a state before joining, FIG. 2B is a perspective view showing a state after joining, and FIG. FIG. 4 is a plan view of a joint portion between main beams in a circumferential direction of a tunnel.

FIG. 3 is a perspective view showing a joint portion between steel segments adjacent to each other in a circumferential direction of a tunnel, (a) is a perspective view showing a state before joining, and (b) is a perspective view showing a state after joining.

FIGS. 4A and 4B show a shield tunnel having a composite structure of steel and reinforced concrete, in which FIG. 4A is a partial perspective view, FIG. 4B is a partial perspective view of a lining body, and FIG. .

FIGS. 5A and 5B show a large-section tunnel constructed by a composite structure of steel and reinforced concrete, in which FIG. 5A is a cross-sectional view, FIG. 5B is a partial perspective view of a lining body, and FIG. It is.

6 (a) to 6 (e) are process diagrams showing a method of joining steel segments adjacent in the circumferential direction of the tunnel.

FIG. 7 is a sectional view of a large-section tunnel constructed of a composite structure of steel and reinforced concrete.

FIG. 8 is a perspective view showing an example of a conventional steel segment.

FIG. 9 shows a joint of steel segments adjacent to each other in the circumferential direction of the tunnel by short bolts, (a) is a cross-sectional view thereof,
(B) is sectional drawing which shows the state after deformation | transformation.

FIG. 10 is a sectional view showing a joint of a steel segment adjacent to a tunnel in a circumferential direction by a high-strength bolt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Steel segment 2 Joint plate 3 High-strength bolt 4 Short bolt 5 Main girder 6 Vertical rib 7 Joint plate 8 Reinforcement plate 9 Lattice frame 10 Skin plate 11 Bolt hole 12 Bolt hole 13 Vertical hole 14 Uneven portion 15 Concrete 16 Reinforcement Reinforcing bar 17 Outer part

Claims (7)

[Claims] In a joint structure of a steel segment having a main girder and a joint plate respectively extending in a circumferential direction and an axial direction of a tunnel, the main girder is connected with a plurality of short bolts penetrating the joint plate in a circumferential direction of the tunnel. A joint structure for steel segments, wherein the joint is formed by a plurality of high-strength bolts penetrating in the axial direction of the plate and the tunnel. 2. The joint structure for a steel segment according to claim 1, wherein a contact surface between the main girder and the joint plate is formed in a rough surface or an uneven shape. 3. A method of joining steel segments having a main girder and a joint plate respectively extending in the circumferential direction and the axial direction of the tunnel, wherein the joint plate is first joined by a plurality of short bolts penetrating in the circumferential direction of the tunnel. Next, a method of joining steel segments, wherein the main girders are joined with a plurality of high-strength bolts penetrating in an axial direction of the joint plate and the tunnel. 4. Excavation while lining a single shield tunnel with a steel segment, and then joining the steel segments when constructing a tunnel by casting concrete to a predetermined thickness in the single shield tunnel. In the method of jointing steel segments, when excavating a single shield tunnel, steel segments are joined with a plurality of short bolts penetrating in the circumferential direction of the tunnel, and then the steel segments are joined before casting concrete. A method for joining steel segments, comprising joining a plate and a plurality of high-strength bolts penetrating in the axial direction of a tunnel. 5. After excavating a plurality of single shield tunnels while covering them with steel segments, concrete is poured into the single shield tunnel to form an outer shell portion, and then earth and sand in the outer shell portion are formed. When constructing a tunnel with a large cross section by excavating a steel section, in the method of joining steel segments to join the steel segments, a plurality of short sections penetrating the steel segments in the circumferential direction of the tunnel during excavation of a single shield tunnel. A method for joining steel segments, wherein the steel segments are joined together by bolts and then a plurality of high-strength bolts penetrating in the axial direction of the joint plate and the tunnel before casting concrete. 6. The method for joining steel segments according to claim 4, wherein a contact surface between the main girder and the joint plate is formed in a rough surface or an uneven shape. 7. A bolt hole for fastening a high-strength bolt, wherein a part of the bolt hole is formed when the steel segment is manufactured, and the rest is formed when the high-strength bolt is fastened. A method for joining a steel segment as described.